Brushstrokes - October 2011 - Surface Coatings Association of New ...
Brushstrokes - October 2011 - Surface Coatings Association of New ...
Brushstrokes - October 2011 - Surface Coatings Association of New ...
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www.scanz.org.nz<br />
OCTOBER <strong>2011</strong><br />
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Rheology Modifiers<br />
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Resins<br />
Acrylic polyols<br />
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hydrocarbon resins<br />
Phenolics<br />
Silicones and Siloxanes<br />
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AntiCorrosives<br />
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This edition was intended to have Titanium<br />
dioxide as its theme but as usual following<br />
the conference, there is some spill over in this<br />
issue and for the next. In this edition we have the full<br />
transcript <strong>of</strong> Adam Berry’s article kindly given to us by<br />
Nuplex Industries Ltd. Adam has joined Rocket Lab<br />
Ltd, a new Zealand based company that is developing<br />
niche technologies in electronics and propulsion<br />
system for rockets. Who would have believed that paint<br />
technology could lead to Rocket Science? Of course<br />
some would say that Rocket Science is no longer<br />
Rocket Science! NASA are planning to hand launch<br />
capability over to the private sector on the grounds<br />
that rocket science has become common science. I<br />
think there may be some pain ahead.<br />
Speaking <strong>of</strong> rocket science, we see from Peter’s<br />
painted memories, that early titanium dioxide started<br />
life as a coprecipitated anatase and barium sulphate<br />
and eventually to uncoated grades in the early 1940’s.<br />
Uncoated titanium dioxide has highly catalytic<br />
effect on any organic binding resins and must have<br />
produced some fierce chalking. The advent <strong>of</strong> surface<br />
treated grades greatly improved the performance as<br />
we see today. Couple that with the improvements in<br />
additives and titanium almost stirs straight into many<br />
paint formulations without the need for prolonged<br />
dispersion. When I started in the paint industry,<br />
everything was done in a ball mill, even laboratory<br />
samples. How many people even remember how to<br />
formulate for a ball mill?<br />
Throughout the time that I have been associated with<br />
the paint industry, the titanium dioxide producers<br />
have been threatening short supply and high prices as<br />
the cost <strong>of</strong> production and the market price squeezed<br />
pr<strong>of</strong>its, or so we were always lead to believe. We even<br />
had some Japanese suppliers use the <strong>New</strong> Zealand<br />
market to get established and then “turn <strong>of</strong>f the tap”<br />
so to speak. Titanium is probably better value in real<br />
dollar terms than it has ever been and with a rebound<br />
recession predicted, the paint industry will no doubt<br />
feel the effects very early in the cycle, resulting in less<br />
pressure on prices. Let’s hope our own paint industry<br />
will be in position to take advantage <strong>of</strong> it.<br />
<strong>Brushstrokes</strong><br />
Editorial<br />
The committee is in the advanced stages <strong>of</strong> planning<br />
for a seminar to be held in mid <strong>October</strong>, similar to the<br />
very successful one held back in 2004. The theme<br />
is basic paint technology, intended fort technicians,<br />
people in sales that think they know it all but <strong>of</strong>ten<br />
don’t, old hand like me that have forgotten it or have<br />
holes in their knowledge they don’t even know about,<br />
or anyone else that is interested to learn, or re learn,<br />
some <strong>of</strong> the fundamentals again. With the changes<br />
that have taken place in the last 10 years or so, there<br />
is always something new to be learnt. Look out for the<br />
notice later in the journal.<br />
In that regard, the <strong>Coatings</strong> and Polymer Science<br />
course is still available at the University <strong>of</strong> Auckland.<br />
It is administered by Neil Edmonds and run at<br />
Tamaki Campus in Glen Innes. The course has<br />
been amalgamated into the polymers and plastics<br />
program and run in conjunction between the School<br />
<strong>of</strong> Chemical Sciences and Engineering and Materials<br />
Science. More details next issue for those that would<br />
like to take their knowledge to a higher level with a<br />
recognised qualification.<br />
CJB.<br />
The theme <strong>of</strong> the next issue is<br />
Ro<strong>of</strong> <strong>Coatings</strong>.<br />
Any technical, historical or market oriented<br />
articles to do with the paint for ro<strong>of</strong>s, painting<br />
ro<strong>of</strong>s or the substrates that ro<strong>of</strong>s are made<br />
from, will be gratefully accepted.<br />
Please send any ideas, articles<br />
or suggestions to the editor.<br />
Email: cbolt@xtra.co.nz<br />
Phone: 021 897 844.<br />
or by mail to PO Box 1282, Pukekohe 2340<br />
Advertising enquires: Marina on<br />
021 781 968 or marina@apconz.co.nz<br />
Visit the SCANZ website<br />
www.scanz.org.nz<br />
SURFACE COATINGS ASSOCIATION OF NEW ZEALAND 1
Painted Memories<br />
A selection <strong>of</strong> Historical Paint References compiled by Peter Walters<br />
Titanium Dioxide, the theme <strong>of</strong> this edition <strong>of</strong> <strong>Brushstrokes</strong>, is,<br />
in spite <strong>of</strong> its now almost universal use as the white opacifying<br />
pigment in most industries, a very recent addition to our<br />
formulating armoury. Titanium Dioxide has only been produced<br />
commercially since 1919, initially by two companies, sharing<br />
technology and development efforts, in Fredrikstad, Norway &<br />
Niagara Falls, USA.<br />
The first Titanium Dioxide products consisted <strong>of</strong> 25% anatase<br />
TiO2 co-precipitated with 75% barium or calcium sulphate.<br />
These pigments gave between three and four times as much<br />
hiding as the then commonly used white lead. This quantum<br />
leap in performance sounded the death knell <strong>of</strong> white lead as<br />
an effective opacifying pigment. However initial cost <strong>of</strong> these<br />
‘high performance’ pigments relegated their early use to quality<br />
and specialised paints, providing the white lead industry with<br />
breathing space.<br />
The crucial dates in the adoption <strong>of</strong> TiO2 as our preferred<br />
white opacifying pigment are 1920, the first commercial TiO2<br />
composite products became available for purchase, 1928,<br />
‘Pure’ anatase pigments, 1940, ‘Pure’ rutile pigments and 1951<br />
the first surface treated TiO2 products became commercially<br />
available. During the 1950’s TiO2 replaced most previous white<br />
opacifiers as the pigment <strong>of</strong> choice.<br />
This timeline is reflected in the historic texts in my personal<br />
library. The Certain-teed Paints Varnishes handbook <strong>of</strong> 1928<br />
mentions Titanox, a 30% titanium oxide co-precipitated<br />
with 70% barium sulphate, and Titanolith, a very new coprecipitated<br />
three component pigment consisting <strong>of</strong> 15%<br />
titanium oxide, 25% zinc sulphide and 60% barium sulphate.<br />
The handbook contains the comment “Titanium oxide itself<br />
is a very excellent pigment but it is so expensive that it could<br />
not be put to general use.” Even the article on Titanox states<br />
that “Its relatively high cost causes it to be replaced whenever<br />
possible by combinations <strong>of</strong> other pigments which possess<br />
equally good properties.”<br />
By 1935 The Modern Painter and Decorator stated, under an<br />
entry for Titanium Oxide, that it was a “comparatively new<br />
addition to the range <strong>of</strong> white pigments” that had the chief<br />
disadvantage <strong>of</strong> an “expense which has prevented it from being<br />
so widely employed as it deserves to be.”<br />
My extract for our theme is from von Fischer’s comprehensive<br />
textbook “Paint and Varnish Technology” published in 1948 by<br />
the Reinhold Publishing Company. I have chosen to reproduce<br />
the first part <strong>of</strong> Chapter 5 as it comprehensively contrasts and<br />
compares all white opacifying pigments used in the coatings<br />
2 SURFACE COATINGS ASSOCIATION OF NEW ZEALAND<br />
industry at a point in time when Titanium Dioxide was just<br />
coming to dominate this field. A coatings text, therefore, had to<br />
compare TiO2 with the existing technologies that the coatings<br />
technologists at the time would have been familiar with. This<br />
textbook was also published prior to the introduction <strong>of</strong> surface<br />
treated grades <strong>of</strong> TiO2 and at a time when anatase TiO2 was<br />
considered the appropriate choice for exterior white house<br />
paints because <strong>of</strong> the “self-cleaning” properties brought about<br />
by its free-chalking characteristics.<br />
White Hiding Pigments<br />
By W. H. Madson<br />
Pigments Department, E.I. duPont deNemours & Co., Inc.,<br />
Wilmington, Delaware<br />
In this chapter there will be a general consideration <strong>of</strong> the<br />
various white hiding pigments in common use. This subject<br />
is a very large one; therefore it will not be covered completely<br />
but only the more important points will be considered. There<br />
isn’t any good short definition <strong>of</strong> what we mean by a white<br />
hiding pigment. However, it may be defined as a material which<br />
“tends to color something white.”<br />
In order to clarify the topic under consideration it is best to list<br />
the white hiding pigments which will be taken up. The following<br />
are included:<br />
White lead (basic carbonate) Titanium dioxide (Rutile)<br />
White lead (basic sulfate) Titanated Lithopone<br />
Zinc oxide Zinc sulfide-barium<br />
Leaded zinc oxide Zinc sulfide-calcium<br />
Lithopone Zinc sulfide-magnesium<br />
Zinc sulfide Antimony Oxide<br />
Titanium-barium pigment Lead titanate<br />
Titanium-calcium pigment Basic lead silicate<br />
Titanium-magnesium pigment Zirconium oxide<br />
Titanium dioxide (Anatase) Lead tetra-phosphate<br />
Of these 20 white pigments, white lead is the oldest, while<br />
titanium dioxide (pure and extended) is the most important<br />
today. The last three are relatively new in the pigment field.<br />
Probably more will be learned about these in future years.<br />
Figures 2 and 3 summarize the production figures <strong>of</strong><br />
three important pigments. A study <strong>of</strong> these graphs reveals<br />
interesting information on the production <strong>of</strong> these materials.<br />
Attention is called to the effect <strong>of</strong> the depression years and<br />
how the introduction <strong>of</strong> a new pigment tends to affect one<br />
already in production.
Fig. 2 Some white pigment sales.<br />
Fig. 3<br />
As mentioned above White lead is the oldest white pigment<br />
in use today. It was known at least 400 B.C. The first plant<br />
in America was built in 1804 by Samuel Wetherill & Sons<br />
in Philadelphia. There have been recent advances in the<br />
improvement <strong>of</strong> manufacture which is enabling the industry<br />
to make better white lead pigment. It is manufactured by<br />
five different processes. These vary primarily in the type <strong>of</strong><br />
raw material used.<br />
The oldest process is probably the Dutch process, which<br />
uses refined metallic lead in the form <strong>of</strong> perforated discs. It<br />
takes about three months to make the white lead. The Carter<br />
process dates from 1885. It uses powdered lead in revolving<br />
wooden cylinders and takes only 12 days. The Euston process<br />
puts the refined lead in solution and precipitates the white<br />
lead. Feathered lead is used as the raw material, which is<br />
made by running molten lead into water. The Sperry process<br />
is the electric process using a lead anode and iron cathode.<br />
The electrolytes, sodium acetate and sodium carbonate, are<br />
separated by a membrane. The Thompson-Stewart process is<br />
a recent development similar to the Carter process in that lead<br />
oxide is formed. However, all the lead oxide is first formed;<br />
then carbon-dioxide is added and controlled to form a definite<br />
chemical compound: 4PbC03.2Pb(OH)2.PbO.<br />
Basic carbonate white lead has the ability to impart adhesion,<br />
toughness, elasticity, and durability to a paint. It is used in<br />
various types <strong>of</strong> paint, principally in exterior paints. Basic<br />
carbonate white lead is the only white pigment which will<br />
produce a durable exterior paint if used alone without other<br />
pigments. A large proportion <strong>of</strong> the total white-lead production<br />
is used in white-lead pastes, which are thinned to paint form<br />
by the painter or other consumer. The two types <strong>of</strong> commercial<br />
white-lead paste are heavy paste and s<strong>of</strong>t paste. The first is<br />
composed <strong>of</strong> about 91 per cent white lead and 9 per cent<br />
linseed oil, while the latter contains about 89 per cent white<br />
lead, 9 per cent linseed oil, and 2 per cent turpentine. The<br />
linseed oil used is refined oil with an acid number <strong>of</strong> 6 to 12.<br />
About 95 per cent <strong>of</strong> the total production <strong>of</strong> white lead is<br />
consumed by the paint industry, with a small amount used in<br />
putty and by the ceramic and other industries.<br />
Basic lead sulfate is quite widely used as a paint pigment.<br />
It is called white basic lead sulfate, basic sulfate white lead<br />
or “sublimed white lead.” White basic lead sulfate is a quite<br />
recent pigment in comparison to basic carbonate white lead.<br />
It was originated in 1855 by E. O. Bartlett. He was at that<br />
time making zinc oxide directly from zinc ores by the American<br />
process. Applying the same principles to the production <strong>of</strong> a<br />
lead pigment from lead ore, he found that it was possible to<br />
produce a white powder having pigment properties.<br />
The first plant was built in 1876 in Joplin, Missouri, where lead<br />
ore deposits were sufficiently free from other metals for the<br />
production <strong>of</strong> white basic lead sulfate. It is manufactured by two<br />
processes, called the fume process and the chemical process;<br />
these are self-explanatory as far as manufacturing is concerned.<br />
Almost the entire production <strong>of</strong> white basic lead sulfate goes into<br />
mixed-pigment exterior paints, either directly or as the basic lead<br />
sulfate portion <strong>of</strong> blended leaded zinc oxides.<br />
White basic lead sulfate, like basic carbonate white lead, has<br />
the ability to impart to paints adhesion, toughness, elasticity,<br />
and durability, but is not as effective in this respect as is the<br />
basic carbonate. In exterior mixed-pigment paints, it is used<br />
principally as a substitute for basic carbonate white lead.<br />
White basic lead sulfate may be used for the “white lead”<br />
content <strong>of</strong> many specification paints, such as Federal<br />
Specification paints TT-P-40 and TT-P-81. White basic lead<br />
sulfate is a less expensive pigment than basic carbonate<br />
white lead, and this has been an influencing factor in its<br />
use. White basic lead sulfate is not generally used for singlepigment<br />
paints or pastes but is used in conjunction with<br />
other pigments in ready-mixed exterior paints. Ninety-seven<br />
per cent <strong>of</strong> the total production <strong>of</strong> this material is used in<br />
the paint industry, the remaining 3 per cent being used in<br />
the rubber and other industries.<br />
Zinc oxide pigments are made primarily by either the American<br />
or French process. In both these processes the characteristics<br />
<strong>of</strong> the pigment are determined by:<br />
1. The temperature <strong>of</strong> the oxidation <strong>of</strong> the fume;<br />
2. The time the zinc oxide is held at a high temperature;<br />
3. The composition <strong>of</strong> the gases;<br />
4. The rate <strong>of</strong> cooling.<br />
SURFACE COATINGS ASSOCIATION OF NEW ZEALAND 3
The French process uses purified metal which is melted and<br />
vaporized at 1650 to 1850°F under controlled conditions. The<br />
main difference in the American process is that this process<br />
uses ore instead <strong>of</strong> refined metal.<br />
However, the effects for which it is used in paints can be<br />
summarized, together with the known or suggested explanations<br />
for the results:<br />
“Use <strong>of</strong> Zinc Oxide in Paints (Nelson-Mattiello)<br />
To aid mixing and grinding - Consistency control - Penetration<br />
control and sealing - Drying - Hardening or solidifying the film<br />
Gloss and gloss retention - To minimize discoloration and<br />
yellowing - Reduced chalking - Color and tint retention<br />
Dirt shedding (self-cleansing), washability, and ease <strong>of</strong><br />
polishing - Mildew control - Resistance to moisture and to<br />
blistering under moist conditions - Neutralizing and inhibiting”<br />
Leaded zinc oxide was first introduced into the paint industry<br />
about 1896 as a result <strong>of</strong> developments on smelting Colorado<br />
complex zinc and lead ores. With improvements in the<br />
manufacturing process the product was standardized. Several<br />
grades were developed containing 5, 20 and 35 per cent lead<br />
sulfate and basic lead sulfate, the remainder being zinc oxide.<br />
The more recent developments have been the introduction <strong>of</strong><br />
a 50 per cent grade <strong>of</strong> leaded zinc and the manufacture <strong>of</strong><br />
leaded zinc oxides by blending white basic lead sulfate and<br />
lead-free zinc oxide. A considerable portion <strong>of</strong> the leaded zinc<br />
oxide on the market today is entirely or in part a mechanical<br />
mixture. Practically the entire production <strong>of</strong> leaded zinc oxide<br />
is used by the paint industry. It is used in conjunction with<br />
other white pigments in exterior house paints. When leaded<br />
zinc oxide is used in a paint it usually furnishes the entire<br />
amount <strong>of</strong> zinc oxide required in the particular paint.<br />
Co-fumed leaded zinc is made in the same general manner as<br />
American process lead-free zinc oxide. Dry-mixing zinc oxide<br />
and basic lead sulfate in the proper proportions yields blended<br />
leaded zinc oxide.<br />
Lithopone was not very important for some time after its<br />
introduction. This is <strong>of</strong>ten characteristic, and some attribute this<br />
condition to the fact that people do not like to make changes.<br />
However, the fact that lithopone was not light-stable prior to<br />
about 1920 no doubt had a definite effect on its acceptance. The<br />
improvement in lithopone at this time was very marked and made<br />
it possible for the material to be used much more widely than<br />
previously. Lithopone is primarily used in paints, rubber, textiles,<br />
paper and printing inks. It is receiving very stiff competition from<br />
titanium dioxide and extended titanium dioxide.<br />
High strength lithopones are made by blending lithopone with<br />
zinc sulfide or titanium dioxide. The former are made in several<br />
“strengths,” the 50 to 55 per cent zinc sulfide grade being<br />
the most popular. This is also known as zinc sulfide-barium<br />
pigment. Blends with titanium dioxide are called “titanated<br />
lithopones,” and usually contain about 15 per cent <strong>of</strong> titanium<br />
dioxide. Also in this same class are the zinc sulfide-calcium<br />
and zinc sulfide-magnesium pigments; these are blends <strong>of</strong> zinc<br />
sulfide with calcium sulfate or magnesium silicate.<br />
4 SURFACE COATINGS ASSOCIATION OF NEW ZEALAND<br />
Zinc sulfide is a relatively high-strength pigment, but it has not<br />
been used as widely as the blends with lithopone or extenders.<br />
Extended titanium pigments were introduced shortly after World<br />
War I. First to be produced was titanium-barium pigment,<br />
consisting <strong>of</strong> 25 per cent titanium dioxide and 75 per cent<br />
barium sulfate. Later came titanium-calcium pigment, with 30<br />
per cent titanium dioxide, and a 30 per cent titanium-barium<br />
pigment. Relatively recently, titanium-magnesium pigment (30<br />
per cent titanium dioxide and 70 per cent magnesium silicate)<br />
was made for use in house paints.<br />
These pigments, particularly straight titanium dioxide, met<br />
great resistance because <strong>of</strong> their relatively high price per<br />
pound, and a long educational program was required to<br />
convince the pigment users that these prices were really low<br />
when considered on the basis <strong>of</strong> cost per unit <strong>of</strong> hiding power<br />
developed in the finished product.<br />
Fig. 4 Titanium dioxide pigment<br />
Titanium dioxide has the highest hiding power <strong>of</strong> any <strong>of</strong> the<br />
white pigments, but its manufacture is more complicated and<br />
more expensive than any <strong>of</strong> the other pigments which have been<br />
considered. Figure 4 shows the manufacture <strong>of</strong> titanium dioxide<br />
pigment. Examination <strong>of</strong> this flow sheet shows how complicated<br />
the manufacture <strong>of</strong> this pigment really is. In order to<br />
manufacture pigment <strong>of</strong> a high quality today, extreme care must<br />
be taken in all steps, and impurities controlled very accurately.<br />
Previously the subject <strong>of</strong> hiding power was mentioned. It is<br />
this quality <strong>of</strong> titanium dioxide that makes it very important in<br />
the paint field. The comparison <strong>of</strong> the hiding power <strong>of</strong> various<br />
pigments is given in Figure 5. There may be some disagreement<br />
in the actual values <strong>of</strong> hiding power. This disagreement is<br />
due primarily to the fact that different conditions are used in<br />
measuring it. However, in general, the order given in Figure 5<br />
will be found under usual conditions.<br />
Fig. 5 Comparison <strong>of</strong> hiding power <strong>of</strong> various pigments.
A Naturally Occurring Sub-Micron Titanium<br />
Dioxide Extender for Decorative Paints<br />
Introduction<br />
By Simon Bussell*, Technical Sales Manager, Sibelco Speciality Minerals Europe * Corresponding author<br />
Mart Verheijen, Application Development Manager, Sibelco Speciality Minerals Europe<br />
In the first quarter <strong>of</strong> 2009 the price <strong>of</strong> titanium dioxide (TiO2)<br />
stood at $2,400/tonne for the US and Asia. Since that time<br />
regular increases have seen the price increase dramatically<br />
to $2,750-2,950/tonne by the end <strong>of</strong> 2010. Prices are even<br />
higher in Europe at up to €2,780/tonne.‚ At the same time<br />
supply has been severely limited with manufacturers rationing<br />
deliveries to customers. There are several causes for this,<br />
shortages <strong>of</strong> titanium ores such as ilmenite and rutile as well<br />
as other raw materials such as sulphuric acid, increased energy<br />
costs, increased demand from Asia and capacity reduction by<br />
suppliers. This situation has forced formulators to look again<br />
at the level <strong>of</strong> TiO2 in their coatings and consider options for<br />
reducing the quantities used. One such option is a complex<br />
carbonate extender produced by the Sibelco Group company<br />
Ankerpoort based a mixture <strong>of</strong> calcium and magnesium<br />
carbonates and hydrated carbonates. The material is marketed<br />
by Sibelco Speciality Minerals Europe (SSME) a new<br />
commercial group focused on the supply <strong>of</strong> functional fillers for<br />
coatings, polymers and adhesives. This work will show that the<br />
mixture, which occurs naturally as sub-micron, platy crystals,<br />
is an ideal TiO2 extender, maintaining and improving brightness<br />
and hiding power in comparison to other ultrafine extenders.<br />
Experimental<br />
Titanium Dioxide is responsible for two principle features <strong>of</strong><br />
paints and coatings, whiteness and opacity. TiO2 is the best<br />
pigment for these properties because <strong>of</strong> its high refractive<br />
index (2.75). This gives the highest level <strong>of</strong> scattering when<br />
light crosses the boundary between binder and TiO2 particle or<br />
air and TiO2 particle. Reduction <strong>of</strong> TiO2 content is a balancing<br />
act between the need to reduce cost and the need to maintain<br />
quality. To be effective a TiO2 extender must allow TiO2 levels to<br />
be reduced while maintaining whiteness and opacity levels.<br />
In the 1970’s a wall paint could contain more than 18% TiO2 by<br />
volume. 3 This has been steadily reduced since that time, typically<br />
by improving the dispersion and separation <strong>of</strong> TiO2 particles in the<br />
film. Figure 1 shows diagrammatically how this can be done by<br />
reducing the average particle size <strong>of</strong> the filler material.<br />
There is a limit to how effective this method can be. Beyond<br />
a certain particle size suitable finely ground fillers may not be<br />
available, and if they are binder demand, dispersant levels and<br />
dispersion time would all be increased. An alternative method<br />
is to use ultrafine particles to space the TiO2 particles in the<br />
interstitial voids between large filler particles (figure 2). Typically<br />
Figure 1 – improved TiO2 distribution by reduction <strong>of</strong> filler particle size<br />
(not to scale).<br />
particles <strong>of</strong> around twice the diameter <strong>of</strong> TiO2 particles (0.5-<br />
0.6µm) are found to be most effective.<br />
The purpose <strong>of</strong> this work was<br />
to determine how effective this<br />
complex carbonate mineral<br />
is as a TiO2 extender. To do<br />
this it was compared with four<br />
other materials commonly<br />
used for TiO2 extension, finely<br />
ground calcite, precipitated<br />
calcium carbonate, fine<br />
hydrous kaolin and calcined<br />
kaolin at two different TiO2<br />
volume concentrations.<br />
Figure 2 - TiO2 spacing by ultrafine extender (not to scale)<br />
Materials<br />
This work was undertaken at the SSME paint lab in Maastricht<br />
using a formulation (table 1) based on a styrene-acrylic<br />
emulsion. Initially two coatings were prepared using 7% TiO2 by<br />
volume and 3.5% TiO2 by volume. Selected coatings from these<br />
trials were repeated using a higher binder level. With the PVC<br />
above critical and a low level <strong>of</strong> TiO2 these coatings were felt to<br />
represent a general use interior wall paint.<br />
Fillers<br />
The complex carbonate extender is a mixed alkaline earth<br />
carbonate with the general formula Mg3Ca(CO3)4. It is formed<br />
by the weathering <strong>of</strong> magnesite or dolomite and subsequent<br />
deposition. Ankerpoort mine and partially process the material<br />
in Greece (figure 3) where the raw material is screened and<br />
beneficiated to provide a reasonably pure feedstock for further<br />
processing. The material is then shipped to The Netherlands<br />
where Ankerpoort have developed proprietary processing<br />
SURFACE COATINGS ASSOCIATION OF NEW ZEALAND 5
Table 1 – interior wall paint formulation<br />
techniques to achieve the optimum particle size distribution without<br />
affecting the unique morphology. The deposit is fine and white with<br />
a high carbonate content and an iron content <strong>of</strong> only 0.03%.<br />
Details <strong>of</strong> the morphology and physical properties can be seen in<br />
figure 1 and table 1. It occurs naturally as an aggregate <strong>of</strong> platy<br />
crystals with sides <strong>of</strong> ≈ 0.5 – 1.0µm and an aspect ratio <strong>of</strong> 10:1.<br />
The defining properties are the high brightness, low particle size<br />
and the high oil absorption/ surface area. The advantages <strong>of</strong><br />
these properties will be shown in the following work.<br />
The properties <strong>of</strong> the other test fillers (as measured by SSME)<br />
are summarised in table 3. Where quoted, the manufacturers<br />
D50 particle size is also given. Measurements were made using<br />
the Sedigraph technique which is useful for platy materials<br />
such as hydrous kaolin, but can give discrepancies for round<br />
or needle shaped particles such as PCC. A lower value would<br />
be expected for the calcined kaolin suggesting this sample was<br />
highly agglomerated.<br />
Methods<br />
7% TiO2<br />
7% TiO2<br />
+ 20%<br />
Binder<br />
3.5% TiO2<br />
Dispersion - All coatings were produced using a high speed<br />
disperser with a toothed blade. The water, dispersants, calcium<br />
scavenger, biocide, antifoam and thickener were dispersed at<br />
6 SURFACE COATINGS ASSOCIATION OF NEW ZEALAND<br />
3.5% TiO2<br />
+ 10%<br />
Binder<br />
Water 270 270 270 270<br />
Dispersant A 4 4 4 4<br />
Na HMP 1 1 1 1<br />
Dispersant B 1 1 1 1<br />
Biocide 3 3 3 3<br />
Antifoam 2 2 2 2<br />
Cellulose thickener 3 3 3 3<br />
TiO2 80 80 40 40<br />
5µm GCC 290 290 290 290<br />
Test extender 100 100 140 140<br />
Talc 80 80 80 80<br />
Styrene Acrylic<br />
binder<br />
160 192 160 176<br />
Thickener 3 3 3 3<br />
TiO2 PVC 7 6.7 3.5 3.4<br />
Total PVC 72.2 68.4 72.7 70.8<br />
Figure 3 Ankerpoort mine in Greece<br />
Figure 4 (left) - Morphology <strong>of</strong> complex carbonate extender<br />
Table 2 - Physical properties <strong>of</strong> complex carbonate extender<br />
Density 2.7g/cm3<br />
Mohs Hardness 2 - 3<br />
Refractive index 1.61 – 1.64<br />
D50 (Sedigraph) 0.56µm<br />
Oil Absn 55-60g/100g<br />
BET 18m2/g<br />
Brightness (Ry) 95<br />
Brightness (ISO) 92.3<br />
pH 10<br />
Table 3 – physical properties <strong>of</strong> competitive test extenders<br />
Fine GCC PCC<br />
low speed until fully dissolved. The pigment, fillers and extender<br />
were added and dispersed at high speed for 30 minutes until a<br />
grind <strong>of</strong> 5 or better was achieved. Following this the binder and<br />
thickener were added and dispersed at low speed for a further<br />
30 minutes until a uniform dispersion was achieved.<br />
Brightness and contrast ratio - The coatings were drawn<br />
down onto a Leneta No. 2 opacity chart using a bird type<br />
applicator to give a 150µm wet film thickness and allowed<br />
to dry for 7 days. Brightness was measured as L* using a<br />
spectrophotometer. Contrast ratio was measured as the ratio<br />
<strong>of</strong> reflected light from the coating over the black and white<br />
portions <strong>of</strong> the card (RB/RW) expressed as a percentage.<br />
Viscosity measurement - Viscosity was measured using a<br />
Brookfield viscometer fitted with spindle 5. High and low shear<br />
measurements were made at 100rpm and 10rpm.<br />
Results and discussion<br />
Hydrous<br />
Kaolin<br />
Calcined<br />
Kaolin<br />
Density 2.7 2.6 2.6 2.6<br />
D50 (Sedigraph) 1.1 1.38 0.62 6.6<br />
D50 (TDS) 0.2 - 0.3 0.7<br />
Oil Absn 30.5 37.5 42.0 74.5<br />
Brightness (ISO) 91.0 95.5 85.5 90.9<br />
The results for all test measurements are shown in table 4a and<br />
4b. There was no significant difference in the brightness measured<br />
for all formulations, being in the range 95.0 ± 0.6 although it<br />
should be mentioned that the highest brightness for each series
Table 4a – test results for 7% TiO2 formulation<br />
7% Titan<br />
7% Titan<br />
+ 20%<br />
Binder<br />
was given by the complex carbonate extender. As may be expected<br />
the brightness <strong>of</strong> the coatings containing 7% TiO2 was higher than<br />
those containing 3.5% TiO2, although in reality the difference was<br />
on average only half a point. Gloss measurements were also very<br />
similar for all samples ranging from 2.4 to 3.8. All coating would<br />
be suitable for low sheen applications.<br />
The variation in contrast ratio was far greater, ranging from<br />
a low <strong>of</strong> 90.1 to a high <strong>of</strong> 96.2. Once again the complex<br />
carbonate formulations had the highest value in all test series,<br />
in some cases by a significant margin, being at least two points<br />
above the average value for each series <strong>of</strong> tests. The results<br />
for the fine GCC and the PCC were very similar and it would be<br />
difficult to place one above the other in terms <strong>of</strong> contrast ratio.<br />
The lowest contrast ratio was given by the hydrous and calcined<br />
kaolins which were also very similar. In terms <strong>of</strong> particle size<br />
and shape the hydrous kaolin was closest in morphology to<br />
the complex carbonate, however the results show it is not as<br />
effective as the complex carbonate as a TiO2 extender.<br />
There was some variation between the contrast ratio <strong>of</strong> the<br />
higher and lower TiO2 contents. Increasing the level <strong>of</strong> extender<br />
and reducing the level <strong>of</strong> TiO2 gave a higher contrast ratio for<br />
the complex carbonate, fine GCC and hydrous kaolin while a<br />
lower value for PCC and calcined kaolin.<br />
The area which showed the greatest difference between the<br />
complex carbonate and the other extenders was viscosity.<br />
The GCC, PCC and hydrous kaolin give reasonably similar<br />
viscosities, however the complex carbonate gives a noticeably<br />
higher viscosity and the calcined kaolin a noticeably lower<br />
viscosity. The highly thixotropic nature <strong>of</strong> dispersions<br />
containing the complex carbonate can be an advantage in that<br />
settling is less pronounced and thickener levels can reduced. If<br />
lower viscosities are required then subsequent work has shown<br />
that alternative combinations <strong>of</strong> dispersant and thickener are<br />
Portafill H5 Fine GCC PCC Hydrous Kaolin Calcined Kaolin<br />
Brightness L* 95.8 95.0 95.4 94.9 95.4<br />
CR/% 96.4 92.4 92.5 92.4 90.1<br />
Gloss 85° 2.8 2.4 3.2 2.5 2.6<br />
Viscosity100rpm/cP 2640 1880 2040 1680 1240<br />
Viscosity10rpm/cP 14000 7200 7600 7200 4400<br />
Brightness L* 95.8 95.3<br />
CR/% 95.9 94.9<br />
Gloss 85° 2.6 2.7<br />
Table 4b – test results for 3.5% TiO2 formulation<br />
3.5% Titan<br />
3.5% Titan<br />
+ 10%<br />
Binder<br />
Portafill H5 Fine GCC PCC Hydrous Kaolin Calcined Kaolin<br />
Brightness L* 95.6 94.5 95.1 94.4 94.8<br />
CR/% 95.2 94.3 91.1 92.2 92.0<br />
Gloss 85° 3.6 3.4 3.8 2.9 2.9<br />
Viscosity100rpm/cP 3600 1880 1680 1920 1160<br />
Viscosity10rpm/cP 21200 7600 5600 9200 2000<br />
Brightness L* 93.2 94.4 94.4 94.1<br />
CR/% 94.5 92.0 90.3 91.5<br />
Gloss 85° 3.2 3.1 2.8 3.1<br />
effective in controlling the rheological behaviour.<br />
The relatively low viscosity <strong>of</strong> the mixes containing the calcined<br />
kaolin, despite the highest oil absorption, may be further<br />
evidence <strong>of</strong> the difficulty in deagglomerating the material and<br />
achieving a fine dispersion. This in turn would account for the<br />
poor performance in terms <strong>of</strong> contrast ratio.<br />
Conclusions<br />
SSME’s complex carbonate extender is an ultrafine, platy<br />
extender and has been compared in this series <strong>of</strong> tests against<br />
ultrafine carbonate extenders and ultrafine platy extenders.<br />
Overall the results show that it works well as a TiO2 extender,<br />
brightness in the test formulations was slightly better than<br />
the competitive materials however the most important result<br />
was contrast ratio. In formulations above critical PVC it is<br />
relatively easy to achieve a good brightness using white fillers<br />
but dry hiding power can be difficult to maintain as TiO2<br />
levels are reduced. This work shows that increasing the level<br />
<strong>of</strong> the complex carbonate extender in a formulation allows<br />
the TiO2 level to be reduced while actually increasing the<br />
dry hiding power to a level not achieved by other fillers. This<br />
has advantages both in terms <strong>of</strong> cost reduction and quality<br />
improvement. In addition the rheological behaviour makes this<br />
extender highly suitable for viscous materials such as sealants,<br />
underbody coatings and putties.<br />
References<br />
1. Titanium dioxide price pressure, Industrial Minerals, March 2009<br />
2. Titanium dioxide market most “buoyant” for a decade, Industrial<br />
Minerals, Jan <strong>2011</strong><br />
3. The Effect <strong>of</strong> Fine Particle Size Extenders and Entrapped Air on TiO2<br />
in Emulsion Paints, Paul F. Dietz, PCI Magazine, September 2003.<br />
Contact details<br />
Simon Bussell, Sibelco Europe, Brookside Hall, Sandbach,<br />
Cheshire, UK. Contact: Simon.bussell@sibelco.com,<br />
Ph: +44 1270 752914, +44 7889 057206<br />
SURFACE COATINGS ASSOCIATION OF NEW ZEALAND 7
Formulating for the Future<br />
<strong>New</strong> open-time binder for the Australasian Market<br />
Summary<br />
By S.B. Browning and A. Berry - Nuplex Resins, Australasia<br />
In Australasia, the open time <strong>of</strong> current water borne enamels<br />
is limited by the binder system, which in gloss systems is<br />
about three minutes. Incremental gains in open time may be<br />
made from changing the rheological pr<strong>of</strong>ile and/or with certain<br />
additives, but the open time will still be significantly shorter<br />
than solvent borne systems. In addition these additives have<br />
the potential to compromise the chemical and mechanical<br />
properties <strong>of</strong> the coating and significantly reduce the coverage.<br />
Nuplex Industries acknowledges this fact and has developed an<br />
experimental binder using proprietary binder technology that<br />
gives coatings two and a half times the open time <strong>of</strong> commercial<br />
water borne trim enamels with improved early water resistance.<br />
Introduction<br />
Over the past 15 years, the trim enamel market has undergone<br />
a dramatic shift from solvent borne alkyds to waterborne<br />
acrylic systems. A number <strong>of</strong> reasons have been given for<br />
this including the perceived environmentally friendliness to<br />
hazard mitigation. This transformation has lead to a number <strong>of</strong><br />
advantages, such as water wash up and fast curing times.<br />
However, this transition has exposed the weaknesses<br />
<strong>of</strong> waterborne acrylic trim enamels. Due to their drying<br />
behaviour, the open time and gloss are poorer than the older<br />
solvent borne technologies, whilst their lower solids deliver<br />
poor telegraphing resistance.<br />
To resolve these deficiencies Nuplex Resins embarked on<br />
a project to understand the rheological parameters that<br />
determine open time with the intention <strong>of</strong> developing a series<br />
<strong>of</strong> binders with better application properties without increasing<br />
the concentrations <strong>of</strong> surfactants or solvents. This is important<br />
as the desired improvement in open time should not be at the<br />
expense <strong>of</strong> dry film properties.<br />
What is open time?<br />
Open time is many things to many people. However a good<br />
definition <strong>of</strong> this property was put forward by Reuvers in 1999:<br />
“the period <strong>of</strong> time during curing when small corrections can<br />
be made without leaving clearly visible brush strokes”<br />
This definition covers the time in which a painter can repair<br />
any deformations in the film (the repair time) and the time<br />
when painter can re-brush (the wet edge or lapping time.)<br />
One must bear in mind that this is not only the time when<br />
surface imperfections can flow out <strong>of</strong> the coating but also<br />
when sagging, slumping and runs can occur (Akkerman et al,<br />
8 SURFACE COATINGS ASSOCIATION OF NEW ZEALAND<br />
2009.) All <strong>of</strong> these properties are to do with flow and hence<br />
are related.<br />
Whilst it is generally acknowledged that the high shear viscosity<br />
will determine how much paint is applied and hence wet film<br />
thickness, Bosma et al. found by manipulation <strong>of</strong> the Orchard<br />
equation that a paint will cease flow, levelling and hence<br />
open time once it has reached a certain low shear viscosity<br />
and from this concluded that paints with a high degree <strong>of</strong><br />
pseudoplasticity will always have poor open times.<br />
The differences between solvent borne and<br />
water borne coatings.<br />
There are number <strong>of</strong> reasons why the open times <strong>of</strong> solvent<br />
borne coatings are superior to those <strong>of</strong> their water borne<br />
cousins, but the main reason is the relationship between<br />
fluidity (inverse viscosity) and solids content. Dispersions and<br />
waterborne dispersions in particular decrease their fluidity with<br />
increasing solids at a much faster rate than solutions regardless<br />
<strong>of</strong> solvent content. As a result water borne binders have<br />
virtually no flow above 50%, whilst solvent borne alkyds still<br />
have a degree <strong>of</strong> fluidity at 75% solids. This allows the painter<br />
significantly longer period to work with the coating, hence<br />
better open times, and thus better dry film appearance.<br />
This fluidity effect is exacerbated by the different levelling<br />
mechanisms between water borne and solvent borne coatings.<br />
In the initial phase <strong>of</strong> curing, the evaporate rate is constant<br />
regardless <strong>of</strong> local layer thickness. In solvent based paints<br />
this leads to an increase in surface tension in areas <strong>of</strong> low<br />
film build - as white spirits has a surface tension <strong>of</strong> 24 dynes/<br />
cm whilst the final coatings typically have a surface tension <strong>of</strong><br />
45 dynes/cm. As the surface tension tries to equilibrate, that<br />
is the surface area reduces, material is forced to flow from<br />
locations <strong>of</strong> low surface tension to areas where the surface<br />
tension is higher. This results in a surface tension gradient that<br />
promotes levelling, but this phenomena is opposite for water<br />
based coatings as water has a surface tension <strong>of</strong> 72 dynes/cm.<br />
This factor can be minimized by the addition <strong>of</strong> surfactants<br />
and solvents, but this has a negative effect on hardness<br />
development, water resistance and in the case <strong>of</strong> solvents, an<br />
increase in VOC.<br />
Another reason why waterborne coatings are observed to be<br />
inferior to solvent borne coatings is telegraphing resistance,<br />
the transmission <strong>of</strong> substrate defects from the substrate to the<br />
surface. In the absence <strong>of</strong> surface tension gradients (as occurs<br />
at initial application <strong>of</strong> the coating) the telegraphed amplitude<br />
only depends on the initial solids content (also known as
the shrinkage factor) and is thus irrespective <strong>of</strong> rheological<br />
properties, thickness, applied surface pr<strong>of</strong>ile or surface tension.<br />
The shrinkage factor can thus be modelled as:<br />
where ρ solids is density <strong>of</strong> solids and SC-0 is initial solids<br />
content. Using this formula we can ascertain that by either<br />
increasing the solids content or by decreasing the density <strong>of</strong><br />
the solid, the degree <strong>of</strong> shrinkage can be reduced (See graph<br />
below) In solvent borne coatings, both the solids content is<br />
higher, and due to the higher resin component, the density <strong>of</strong><br />
the solids is lower, hence much better telegraphing resistance.<br />
The Development <strong>of</strong> an Experimental Open<br />
Time Binder<br />
As we have seen, the application and appearance <strong>of</strong> self<br />
cross linking acrylics are inferior to their solvent borne alkyd<br />
predecessors. To try and minimize the shortfall in open-time,<br />
paint chemists commonly add humectants such as glycols or<br />
surfactants; with conventional logic being that these will hold<br />
back water and therefore extend open time.<br />
However propylene glycol does not form an azeotrope 1 with<br />
water, and it is the belief <strong>of</strong> the authors that propylene glycol<br />
only improves the wet edge <strong>of</strong> the paint and not the ability for<br />
a paint to flow out after brush/roller corrections. Significantly<br />
greater gains in open time have been found by slightly reducing<br />
the volume solids content rather than by increasing the<br />
surfactant and solvent concentrations, with only a minimal<br />
reduction in telegraphing resistance.<br />
1 An Azeotropic mixture is defined as a liquid mixture <strong>of</strong> two or more<br />
substances, that when mixed behave as a single species as the<br />
vapour produced from partial evaporation <strong>of</strong> the liquid has the same<br />
composition as the liquid (Turner, 1950.) Whilst propylene glycol is<br />
infinitely dissolvable in water, the resulting liquid exhibits two distinct<br />
boiling points.<br />
Even when the volume solids <strong>of</strong> a coating with a <strong>New</strong>tonian<br />
rheology pr<strong>of</strong>ile is around 35%, the open time using the Nuplex<br />
Cross Open Time (COT) method will be at best between three<br />
and four minutes. This is because the curing mechanism <strong>of</strong> the<br />
resin is the overriding factor in determining the open time in<br />
waterborne acrylic enamel systems.<br />
The self cross-linking acrylic polymers commonly used in the<br />
manufacture <strong>of</strong> trim enamels are classified as dispersions.<br />
In the wet state these resins exist as semi solid particles<br />
suspended in water, and film for through deformation or<br />
coalescence <strong>of</strong> these polymer particles. The dry film retains<br />
some <strong>of</strong> the structure <strong>of</strong> the polymer particles which reduces<br />
the gloss, particularly at 20°. In general the acrylic polymer<br />
particles are high molecular weight and cannot easily move<br />
past one another, so the viscosity increases rapidly on drying,<br />
hence the short open times. These polymers get the majority <strong>of</strong><br />
their performance properties from their high molecular weight<br />
and not from cross-linking, which is why they appear to cure<br />
at a much faster rate than alkyd systems. It is also why acrylic<br />
systems need to have higher glass transition temperatures than<br />
alkyd systems to get the same blocking resistance.<br />
There are two other waterborne technologies that are currently<br />
available for use in the waterborne trim enamel market; alkyd<br />
emulsions and solutions.<br />
Alkyd emulsions are supplied as alkyd droplets in water (an oil<br />
in water or o/w emulsion.) As water evaporates, the viscosity<br />
increases until the resin inverts from an oil in water emulsion to<br />
a water in oil (w/o) emulsion, and the viscosity decreases. The<br />
dry time <strong>of</strong> alkyd emulsions is similar to solvent borne alkyds,<br />
as they both require oxidative cross-linking for chemical and<br />
mechanical properties.<br />
Unlike acrylic dispersions, the resin droplets in alkyd emulsions<br />
are liquid, which gives these binders a higher degree <strong>of</strong> fluidity<br />
at the same solids content, and as alkyd emulsions do not<br />
coalesce, they do not require a coalescing solvent and they<br />
contain renewable (but yellowing) oils. This yellowing and the<br />
slow dry times are two reasons why this technology has fallen<br />
from favour in the Australasian trim market.<br />
Currently the only other technologies that can be utilised are<br />
water soluble polymers. Traditionally the trim market was<br />
dominated by (alkyd solvent borne) solutions, which have<br />
issues with odour, dry time VOCs and yellowing, but have good<br />
open time and telegraphing resistance (due to being able to<br />
flow above 70% volume solids.) Water soluble polymers also<br />
have excellent gloss and open time but perform very poorly<br />
when exposed to water, <strong>of</strong>ten re-dissolving within two minutes.<br />
They mostly have poor mechanical properties.<br />
The Experimental Binder EM8683<br />
These deficiencies in current resin technology have led Nuplex<br />
to develop EM8683, an experimental polymer designed to<br />
have much better open time than current technologies on the<br />
market. As we have already seen, the open time <strong>of</strong> the current<br />
waterborne self cross-linking acrylics is limited by the binder<br />
system. Nuplex have addressed this by developing a fast curing<br />
acrylic copolymer emulsion. Unlike traditional self cross-linking<br />
acrylics, this system is oil modified and oxidatively cross-links,<br />
hence the MFFT is significantly reduced without compromising<br />
mechanical properties.<br />
To ensure that the performance <strong>of</strong> this experimental polymer is<br />
SURFACE COATINGS ASSOCIATION OF NEW ZEALAND 9
similar to current market standards, paints made on EM8683<br />
have been evaluated and compared to six commercially<br />
available paints; three high gloss solvent borne alkyd trim<br />
enamels, two high gloss waterborne trim enamels and a water<br />
based trim enamel based on an alkyd emulsion.<br />
The open time was tested using a standardised method very<br />
similar to ASTM D7488-10, and evaluated a number <strong>of</strong><br />
properties including how long the open time is in the wet (open<br />
time a’) and dry (open time b) films. It was found that the open<br />
time <strong>of</strong> EM8683 was nearly as long as the waterborne alkyd<br />
and 250% longer than a commercial waterborne acrylic market<br />
standards. Significantly, and unlike paints based on self crosslinking<br />
acrylics, the open time in the wet film was identical to<br />
that in the dry film.<br />
As previously mentioned, EM8683 utilises oxidative crosslinking<br />
technology. There have been a number <strong>of</strong> advantages<br />
in doing this, such as reducing the coalescent demand and<br />
improving the resistances to water and hydrophilic stains.<br />
To ensure that the coating did not suffer from loss <strong>of</strong> dry,<br />
it was placed in the oven at 60°C for seven and 42 days<br />
(1000 hours.) In this test it was found that EM8683 had dry<br />
times longer than acrylics but still shorter than solvent borne<br />
enamels. It was also found that the dry time <strong>of</strong> the heat aged<br />
samples was similar to the un-aged sample, unlike three<br />
commercial solvent borne standards.<br />
To observe the mechanical properties <strong>of</strong> the coatings; block<br />
resistance and pendulum (Koenig) hardness tests were<br />
undertaken. Block resistance was carried out using a method<br />
based upon ASTM D4946-89 (2003.) In this test EM8683<br />
had a block resistance within the solvent borne and waterborne<br />
market standards, even though the MFFT <strong>of</strong> EM8683 is much<br />
lower than the self cross-linking acrylics, and a pendulum<br />
hardness akin to the solvent borne alkyds.<br />
Finally the 20° gloss <strong>of</strong> the coating based in EM8683 was<br />
67%. This is a step improvement from the current technology<br />
as it places it roughly half way between the solvent borne<br />
<strong>Coatings</strong> that Michelman has successfully tested for repulpability<br />
and their applications include:<br />
VaporCoat® 330C – a wax replacement solution typically used on roll wrap, produce boxes, poultry boxes and<br />
anywhere packaged goods require protection from water and/or moisture vapor.<br />
Michem® Coat 40EAF - another wax replacement coating that is water resistant and also demonstrates some<br />
grease resistance. Typically used on fruit, vegetable and protein/meat boxes.<br />
Nomar 70AF - a water based, abrasion resistant coating, generally used to provide abrasion protection for gas<br />
flushed food packaging or small appliances.<br />
Coating X300AF - another waterborne coating that provides a high level <strong>of</strong> water resistance and good moisture<br />
resistance on kraft paper. It is used to protect food products from excessive moisture, freezer burn and sticking.<br />
MaxWhite 17 - a decorative white coating that provides excellent brightness before and after wax applications.<br />
10 SURFACE COATINGS ASSOCIATION OF NEW ZEALAND<br />
alkyds and the water borne self cross-linking acrylics.<br />
Conclusion<br />
With commercial pressures from the marketplace and our<br />
share holders, environmental pressures from legislators,<br />
specifiers and consumers and performance pressures from all<br />
<strong>of</strong> the above, we are all continually trying to formulate for the<br />
future. One <strong>of</strong> the last bastions <strong>of</strong> solvent borne technology<br />
in architectural coatings is gloss trim paints. To overcome the<br />
limitations <strong>of</strong> acrylic water borne enamels in both open time<br />
and telegraphing, Nuplex has developed a new binder resin.<br />
Whilst the ultimate parameters <strong>of</strong> this resin are currently being<br />
finalised, the results, thus far, look very promising.<br />
It is anticipated that this binder will be utilised in one <strong>of</strong> two<br />
ways, either in coatings with the same volume solids but much<br />
better open time; or in coatings with higher volume solids to<br />
minimise telegraphing. This second route may be a way <strong>of</strong><br />
reducing TiO2 demand as coverage will be better with the higher<br />
film build. Either way, the coalescent demand will be lower<br />
which may lead to lower formulation costs, reduced VOC’s and<br />
due to the low MFFT and hydrophobic nature <strong>of</strong> this resin, it is<br />
believed that it will be a good candidate for DTS applications as<br />
it is expected have good tannin bleed resistance.<br />
While this polymer is being commercialised we will still be<br />
formulating for the future – working on the next generation<br />
<strong>of</strong> polymers which will give even longer open times and emit<br />
even less VOC’s and having physical and chemical properties in<br />
advance <strong>of</strong> those already achieved.<br />
Acknowledgements:<br />
Nuplex Technical team in Australia and <strong>New</strong> Zealand<br />
Nuplex Technical Team in Holland and Adam Berry<br />
References:<br />
1. Akkerman, J. Bosma, M. Berry, A. Fallani, F. Adolphs, R. Mestach,<br />
D. “<strong>New</strong> developments op open time resins for waterborne<br />
decorative coatings” European <strong>Coatings</strong> Congress, 2009<br />
2. Turner (ed) “The Condensed Chemical Dictionary” Forth Edition,<br />
Reinhold Publishing Corporation, 1950
Bridging the gap in performance deficiency <strong>of</strong><br />
eco-friendly waterborne coatings by making use<br />
<strong>of</strong> a nanoparticle containing additive<br />
Eco-friendly waterborne paints and coatings already gained<br />
considerable interest and market shares compared to traditional<br />
solvent borne systems driven by stricter legislation as well as<br />
the general environmental awareness. Nevertheless waterbornes<br />
have well known limitation in overall performance compared to<br />
classical solvent borne systems.<br />
A innovative concept based on metal oxide nanoparticle<br />
technology potentially improving waterborne coatings will be<br />
introduced. With a chemo-mechanical milling process particles<br />
with tailored surface properties were generated. A overall good<br />
compatibility <strong>of</strong> the particles with a broad variety <strong>of</strong> binders<br />
was observed. Especially acrylic binders and copolymers with<br />
acrylic compartments are very well suited for the use with<br />
Oxylink. This also includes acrylic modified alkyds and PUDs.<br />
MEK double<br />
rubs<br />
[#]<br />
120<br />
80<br />
40<br />
0<br />
? = 85<br />
0.00 1.00 2.00<br />
wt.-% Oxylink 3101 (solids on solids)<br />
Figure 1: Concentration <strong>of</strong> Oxylink 3101 in transparent wood stain<br />
formulation based on Primal AC 337ER versus the<br />
MEK rub resistance<br />
The particles in the additive improve the overall coating<br />
performance due to direct particle-to-resin interaction. This<br />
effect closely depends on the high degree <strong>of</strong> dispersion as<br />
well as on the high surface area <strong>of</strong> the nanoparticles. We<br />
recommend a usage level <strong>of</strong> 1.0 % additive for first formulation<br />
experiments (see. Fig. 1).<br />
In particular the MEK rub stability, drying time, blocking<br />
resistance and stability against humidity will be improved.<br />
Detailed test results for a wood stain and a direct-to-metal<br />
By Marc Herold and Frank Tabellion<br />
Figure 2: Performance charts <strong>of</strong> a transparent Coating for wood based<br />
on Primal AC-337 ER (top) and a white DTM formulation based on<br />
Neocryl XK 86 (bottom).<br />
coating are depicted in Figure 2. The main performance benefit<br />
for the wood coating by the additive is a reduced drying time<br />
and a higher blocking resistance. The humidity resistance and<br />
the MEK-double rub resistance are the main effects for the<br />
direct-to-metal coating.<br />
The above shown results demonstrate that a nanoparticle<br />
based additive like Oxylink can significantly improve the overall<br />
properties <strong>of</strong> waterborne coatings. With steadily improving the<br />
properties <strong>of</strong> waterborne coatings, the gap between waterbornes<br />
and solvent borne coatings becomes narrower and the hurdles<br />
for using waterbornes become lower. As a consequence,<br />
nanotechnology can play an important role in bringing greener<br />
coatings forward.<br />
Bühler PARTEC GmbH<br />
Science Park 2<br />
66123 Saarbrücken<br />
Phone: +49 681 394 6550<br />
oxylink@buhlergroup.com<br />
SURFACE COATINGS ASSOCIATION OF NEW ZEALAND 11
Introduction<br />
To brush or not to brush.<br />
Formulating hand applied waterborne high performance<br />
two pack polyurethane coatings<br />
By Adriaan Sanderse, Jan Goossen, Jaap Akkerman, Dirk Mestach - Nuplex Industries.<br />
Progress made over the last years in the design <strong>of</strong> waterborne<br />
acrylic polyols and polyisocyanates for two pack polyurethane<br />
coatings has enabled the coatings formulator to overcome<br />
the drawbacks that were associated with the first generation<br />
<strong>of</strong> water-borne polyurethanes. Consequently waterborne two<br />
pack (WB2K) technology has gained a strong foothold in the<br />
industrial coatings market, meeting all <strong>of</strong> the requirements to<br />
<strong>of</strong>fer a true alternative for solventborne coatings.<br />
In addition to <strong>of</strong>fering reduced emissions <strong>of</strong> volatile organic<br />
compounds (VOC) during application <strong>of</strong> the coating resulting<br />
in reduced exposure <strong>of</strong> the painter to organic vapours, these<br />
coatings reduce risk <strong>of</strong> fire and are easier to clean up (creating<br />
less hazardous waste to dispose <strong>of</strong>).<br />
Most WB2K coatings have been optimized for application by<br />
means <strong>of</strong> spraying, either airless or air assisted or electrostatic.<br />
Until now, not much work was done to develop formulation<br />
guideline for WB2K systems that can be hand applied, by<br />
roller or brush. However if it would be possible to hand apply<br />
WB2K systems with final aesthetical and film-properties that<br />
are equivalent to spray applied WB2K would open up a number<br />
<strong>of</strong> new end-use applications where properties such as high<br />
durability and excellent resistance properties are <strong>of</strong> prime<br />
importance. Typical examples <strong>of</strong> such end-use applications<br />
are highly durable clear and pigmented exterior woodcoatings,<br />
yacht coatings, site-applied flooring coatings and coatings to<br />
repair or refinish interior wood.<br />
Water-borne two component<br />
polyurethane technology<br />
As for all paint formulation work, the right selection <strong>of</strong> the base<br />
resin components is crucial to obtain a satisfactory end result.<br />
In a WB2K coating system for hand application, component<br />
A is a polyol binder, consisting <strong>of</strong> small colloidal polyol<br />
particles that are suspended in water. Because <strong>of</strong> the fact that<br />
most waterborne acrylic polyols can not sufficiently emulsify<br />
hydrophobic isocyanates to achieve proper homogeneous film<br />
formation 2,1 , component B is preferably a water dispersible<br />
polyisocyanate hardener. Water dispersible hydrophylic<br />
polyisocyanates can be prepared by reacting isocyanate<br />
trimers with mono-functional polyethers 2 . Most suitable<br />
polyisocyanate hardners for this application are based on<br />
hexamethylene diisocyanate (HDI) trimers, however in order to<br />
optimize properties such as hardness development, also water<br />
12 SURFACE COATINGS ASSOCIATION OF NEW ZEALAND<br />
dispersible polyisocyanates based on isophoronediisocyanate<br />
(IPDI) trimers can be used in combination with HDI-types.<br />
Just before application the polyol component is mixed with<br />
the polyisocyanate hardener. After application onto the<br />
substrate, the coating cures through the hydroxyl-isocyanate<br />
reaction resulting in the formation <strong>of</strong> urethane crosslinks. In<br />
waterborne systems a important side-reaction occurs when<br />
isocyanate reacts with water. Some <strong>of</strong> the polyisocyanate<br />
groups are sacrificed because <strong>of</strong> this reaction forming the<br />
unstable carbamic acid which immediately decomposes and<br />
releases CO2 gas and a primary amine. The amine can then<br />
react with the isocyanate forming polyurea. Because <strong>of</strong> the<br />
water side-reaction, the NCO:OH ratio will have a significant<br />
impact on the coating properties: dry times, sanding, pot<br />
life, hardness development and chemical resistance. The<br />
competition between urethane versus urea reaction is<br />
governed by a number <strong>of</strong> parameters such as the surface area/<br />
particle size <strong>of</strong> the polyisocyanate emulsion, the emulsion<br />
stabilization mechanism3 , neutralizing agents and the time<br />
between mixing components A and B and the application <strong>of</strong><br />
the coating. Publications by Urban et al. 4,5 discuss in great<br />
detail the mechanisms and the influence <strong>of</strong> the ratio between<br />
hydrophobic / hydrophilic isocyanates and the curing conditions<br />
such as relative humidity on film-properties.<br />
Binder selection<br />
Most waterborne polyol emulsions are stabilized by either<br />
anionic or non-ionic stabilizing groups or a combination there<strong>of</strong>.<br />
Anionic groups are required for fine particle size emulsions.<br />
Generally there is a relation between the acid value <strong>of</strong> the<br />
polyol and the particle size <strong>of</strong> the emulsion. Most commonly<br />
the anionic groups are introduced by the copolymerization<br />
with carboxylic acid functional (meth)acrylic monomers such<br />
as acrylic or methacrylic acid. The carboxylic acid groups are<br />
converted in the salts using a volatile amine before or during<br />
emulsification in water. The problem associated with the<br />
presence <strong>of</strong> amines in the coating system is the catalytic action<br />
towards the isocyanate-water reaction. In order to decouple the<br />
emulsion particle size with the negative catalytic influence <strong>of</strong><br />
the neutralizing amine, the resin chemists at Nuplex Resins<br />
developed a proprietary technology to replace part <strong>of</strong> the<br />
carboxyl acid groups in the polyol by sulfonate-functional<br />
groups. The advantage <strong>of</strong> the sulfonate functionality is the<br />
fact that these acid groups are neutralized with an inorganic<br />
base that has no unfavourable catalytic action. As a result the<br />
curing <strong>of</strong> the WB2K coating become more controllable and
the flow and levelling properties are positively influenced. Also<br />
the risk <strong>of</strong> CO2 bubbles getting trapped in the drying coating<br />
is reduced. In Table 1 the main properties <strong>of</strong> the waterborne<br />
acrylic polyol used in this study are given.<br />
Table 1. Resin properties.<br />
Hydroxyl value 4.2 % OH<br />
Solids content 47 %<br />
pH 8<br />
Acid value (on solids) 16 mg KOH g mixed<br />
carboxylic and sulfonic<br />
Particle size ± 100 nm<br />
Co-solvent Butyl glycol (approx. 2 %)<br />
Rheology <strong>of</strong> hand applied WB2K coatings<br />
The paint rheology is one <strong>of</strong> the most important parameters<br />
for brush or roller application. When comparing the flow-curve<br />
<strong>of</strong> a conventional solvent-borne 2K paint formulated for hand<br />
application (VOC <strong>of</strong> ± 500 g/l) with that <strong>of</strong> a WB2K system, the<br />
initial flow curves immediately after mixing are quite different<br />
(figure 1).<br />
Figure 1. Flow curve <strong>of</strong> SB 2K and WB 2K paints.<br />
The flow curves also change in a different way as a function <strong>of</strong><br />
the time after mixing (graph 2).<br />
Figure 2. Changes in rheology during the pot-life <strong>of</strong> WB and SB 2K<br />
formulations.<br />
At high shear the viscosity <strong>of</strong> WB2K paint is much lower,<br />
resulting in an initial brush resistance that is far too low.<br />
Furthermore the viscosity decreases during the pot-life, so<br />
application properties become worse after mixing <strong>of</strong> the paint.<br />
Under low shear on the other side, the viscosity is much higher,<br />
with relatively poor flow as a consequence. Because <strong>of</strong> this<br />
rheological behaviour defoaming <strong>of</strong> the paint after application<br />
also becomes difficult.<br />
In order to adjust the rheological behaviour <strong>of</strong> the WB2K paint<br />
a high shear a polyurethane thickener is used to increase<br />
the ICI viscosity to a level <strong>of</strong> 1.6 Poise, similar to that <strong>of</strong><br />
the solventborne paint. By adding the thickener the solids<br />
content <strong>of</strong> the paint could be lowered in order to reduce the<br />
low shear viscosity. This results in adequate brush resistance<br />
in combination with acceptable levelling, flow and defoaming<br />
properties. Most waterborne two pack systems still require the<br />
use <strong>of</strong> some co-solvent and the influence on the rheological<br />
pr<strong>of</strong>ile needs to be taken into account. With this specific polyol<br />
it was found that a mixture <strong>of</strong> butyl acetate, dipropylene glycol<br />
dimethyl ether and butyldiglycol acetate <strong>of</strong>fered the best<br />
results regarding the balance between gloss and levelling. The<br />
flow-curves as function <strong>of</strong> time after mixing for the adjusted<br />
formulation are given in figure 3.<br />
Figure 3. Time dependant flow-curves <strong>of</strong> adjusted formulations.<br />
Formulation parameters for clear and<br />
pigmented coatings<br />
A basic formulation for a hand applied WB2K formulation (both<br />
pigmented and clear) is given in Table 2. The white mill base<br />
used in the pigmented formulation was prepared by dispersing<br />
in a pearl mill 20.12 parts <strong>of</strong> titanium dioxide with 1.03 grams<br />
<strong>of</strong> a dispersant, 0.16 grams <strong>of</strong> thickener and 5.8 grams <strong>of</strong><br />
demineralized water until a Hegmann fineness <strong>of</strong> less than 10<br />
microns was obtained.<br />
During this work it was found that proper selection <strong>of</strong> the high<br />
shear thickener and defoamer is essential to formulate a paint<br />
with a good balance <strong>of</strong> aesthetical and performance properties.<br />
How to achieve proper defoaming<br />
When formulating without a defoamer, the paint, after brush<br />
or roller application will contain at lot <strong>of</strong> foam. After drying<br />
<strong>of</strong> the paint this will result in surface defects such as pinholes<br />
and foam. The selection <strong>of</strong> a defoamer however is<br />
not straight forward as it should ensure proper defoaming<br />
during application without affecting gloss, flow and levelling.<br />
Preferably the defoamer should be easily introduced into the<br />
base without excessive shear.<br />
SURFACE COATINGS ASSOCIATION OF NEW ZEALAND 13
Table 2. WB2K formulations.<br />
Component Raw material Weight<br />
Clear varnish White paint<br />
Polyol<br />
emulsion<br />
51.41 36.37<br />
Wetting<br />
additives<br />
0.52 0.36<br />
Base<br />
High shear<br />
thickener<br />
2.70 1.91<br />
Defoamer variable variable<br />
Hardener<br />
Diluents<br />
Properties<br />
Demineralized<br />
water<br />
13.73 11.86<br />
Mill base<br />
HDI/IPDI<br />
- 27.11<br />
based<br />
hydrophilic<br />
isocyanate<br />
HDI based<br />
9.85 6.97<br />
hydrophilic<br />
isocyanate<br />
8.66 6.12<br />
Co-solvents* 5.82 4.12<br />
Demineralized<br />
water<br />
7.31 5.18<br />
Density (kg/l) 1.04 1.22<br />
Volume solids<br />
(%)<br />
38.9 38.9<br />
Weight solids<br />
(%)<br />
42.3 50.5<br />
VOC ready to<br />
use (g/l)<br />
87 73<br />
NCO/OH ratio 1.25 1.25<br />
* co-solvent mixture consisting <strong>of</strong> butyl acetate:dipropylene glycol<br />
dimethyl ether:butyldiglycol acetate in a ratio <strong>of</strong> 13/74/13.<br />
In the base for the clear varnish formulation given in table 2,<br />
a number <strong>of</strong> different defoamer types were added at different<br />
concentration levels.<br />
All varnish samples were subjected to a foam test that is<br />
carried out as follows: the coating is applied with a pipette to<br />
the white part <strong>of</strong> a black-white paper contrast chart. After that,<br />
Table 3. Results for the foam test in a clear varnish.<br />
14 SURFACE COATINGS ASSOCIATION OF NEW ZEALAND<br />
coating is applied to half <strong>of</strong> the black part <strong>of</strong> the chart using a<br />
brush. The varnish on the white chart is stipulated intensively<br />
with the brush to incorporate a lot <strong>of</strong> air. This varnish is then<br />
brushed over the second half <strong>of</strong> the black part <strong>of</strong> the chart. The<br />
amount <strong>of</strong> foam in the two black parts <strong>of</strong> the chart is judged<br />
after drying overnight according to a scale <strong>of</strong> one (bad) to five<br />
(good). Also the clarity <strong>of</strong> the varnish applied onto glass was<br />
judged after drying. The results are given in table 3.<br />
In the foaming test the defoamers based on a mixture <strong>of</strong><br />
hydrophobic solids and polysiloxanes and the polyether siloxane<br />
defoamer perform well both at high and low addition levels.<br />
However the first type does introduce a strong orange peel<br />
effect in the dried film, even at low concentrations. Also this<br />
defoamer has a negative influence on the clarity <strong>of</strong> the film.<br />
The polyether siloxane defoamer also introduces a slight orange<br />
peel effect, but at low concentrations this is judged to be<br />
acceptable. The defoamer based on the mixture <strong>of</strong> polymers<br />
and hydrophobic solids is somewhat less effective but has<br />
no effect on gloss and haze. At the lower addition level, no<br />
negative effect on the leveling properties was observed.<br />
In order to verify if these defoamers also worked in pigmented<br />
systems, additional tests were performed using the defoamers<br />
at the lowest addition level. Gloss and haze values were<br />
measured for both brush and roller application and are given in<br />
Defoamer Addition level Before After Orange peel Clarity on glass Gloss*<br />
(20°)<br />
None none 2 1 none OK 84 24<br />
Mixture <strong>of</strong> hydrophobic solids<br />
and polysiloxanes<br />
Mixture <strong>of</strong> polymers and<br />
hydrophobic solids<br />
Polyether siloxane copolymer<br />
* applied by brush low=0,17 wt%, high=0,34 wt%<br />
Figure 4. Gloss and haze values for different defoamer types.<br />
Haze*<br />
low 5 5 yes NOK 76 93<br />
high 5 5 yes NOK 82 39<br />
low 4 4 none OK 84 20<br />
high 5 4.5 none OK 83 28<br />
low 5 5 slight OK 84 22<br />
high 5 5 yes OK 84 24
figure 4. Based on these result a final selection was made for<br />
the defoamer based on the polyether siloxane copolymer.<br />
Additional tests have been performed on the final clear varnish<br />
and white paint formulations. The coatings were applied on<br />
glass panels at a wet film thickness <strong>of</strong> 120 microns and dried<br />
at 22 °C and 50% relative humidity: drying and hardness<br />
development were measured. Household chemical resistance<br />
according to the DIN 68861-1A (on oak veneered panels two<br />
coats <strong>of</strong> respectively 175 and 125 microns wet film thickness)<br />
and resistance against methyl ethyl ketone (MEK) were<br />
measured after 1 week <strong>of</strong> drying. Results are given in table 4.<br />
Results at a glance<br />
Waterborne acrylic polyols having mixed carboxylic and sulfonic<br />
stabilization can be used to formulate hand applied two pack<br />
varnishes and paint that show good esthetical properties (gloss,<br />
flow and levelling).<br />
Proper selection <strong>of</strong> the defoamer in the formulation is<br />
essential to get smooth, defect free coatings. Evaluation <strong>of</strong><br />
drying time, hardness build-up and resistance properties show<br />
that these are on the same level <strong>of</strong> conventional solventborne<br />
polyurethane coatings.<br />
These products open up a whole new range <strong>of</strong> end-use<br />
applications for environmentally friendly high performance<br />
coatings where previously only the use <strong>of</strong> high VOC-systems was<br />
a viable option.<br />
Email address: adriaan.sanderse@nuplexresins.com<br />
References<br />
1. M. Melchiors, C. Kobusch, K. Noble, M. Sonntag, H. Casselmann.<br />
‘Aqueous Two-Component Polyurethane (2C-PUR) <strong>Coatings</strong>: An<br />
Evolving Technology’, presented at the International Waterborne,<br />
High Solids and Powder <strong>Coatings</strong> Symposium, <strong>New</strong> Orleans, LA,<br />
February 10, 1999.<br />
2. R. Hombach, H. Reiff, M. Dollhausen, US4663377 to Bayer AG.<br />
3. J. Akkerman, R. Hall, D. Mestach and P. Vandevoorde, sixth<br />
Nürnberg Conference, 2001, 17.<br />
4. D. Otts, M. Urban, Polymer 46 (2005), 2699.<br />
5. D. Otts, K. Pereira, W. Jarret and M. Urban, Polymer 46 (2005),<br />
4600.<br />
Table 4. Testing <strong>of</strong> optimized clear varnish and white paint. Clear Varnish White Paint<br />
Persoz hardness (s) 1 day 107 105<br />
7 days 284 234<br />
BK drying (min) phase I 15 15<br />
phase II 195 210<br />
phase III 360 270<br />
phase IV 570 810<br />
MEK resistance double rubs 68 57<br />
Household chemical resistance (according to DIN 68861-1A) Exposure<br />
5 = no visual damage, 0 = severe damage<br />
ammonia (25 %) 16 h 3 5<br />
ammonia (25 %) 2 m 5 5<br />
50 % ethanol 16 h 5 5<br />
red wine 16 h 5 2<br />
c<strong>of</strong>fee 16 h 5 3<br />
water 16 h 5 5<br />
acetone 16 h 5 5<br />
olive oil 16 h 5 5<br />
mustard 16 h 5 3<br />
black ink 16 h 5 3<br />
cleaning solution 16 h 5 3<br />
SURFACE COATINGS ASSOCIATION OF NEW ZEALAND 15
We invite papers that deliver new perspectives on<br />
· Smarter Manufacturing – Choosing The Right Equipment<br />
· Environmentally Sustainable Manufacturing In NZ<br />
· NZ Made Vs Imports – Keeping NZ Customers Loyal<br />
· The NZ Way – Specific Technical Demands For The NZ Market<br />
· Innovation In NZ<br />
· The Future Of Manufacturing In NZ<br />
· Challenges Of “Economy <strong>of</strong> Scale” And How To Overcome These<br />
· R & D Successful Studies<br />
· Freight Companies Challenges For Import/Export<br />
PAPERS<br />
Oral presentations will be scheduled to suit the final programme and will be delivered as<br />
presentations <strong>of</strong> 35 minutes with 5 minutes question time. There is also the opportunity<br />
for panel and combination presentations to provide a range <strong>of</strong> perspective on an issue<br />
or a cluster <strong>of</strong> related topics in a shorter format. All papers will be evaluated by the<br />
conference committee. Papers accepted will be published in the conference proceedings<br />
exactly as submitted. A short resumé and photo <strong>of</strong> the presenter is required to be sent<br />
with the abstract.<br />
CONDITIONS<br />
Speakers will be provided with registration for the day <strong>of</strong> their presentation allowing<br />
them to attend other sessions and network with the industry participants. Travel,<br />
accommodation and any additional registration costs associated with the<br />
conference are not included.<br />
ABSRACT FORMAT<br />
• An abstract must be no more than 300 words<br />
• The abstract must include the title <strong>of</strong> the presentation<br />
• Please include all authors <strong>of</strong> the submission, indicating the<br />
author presenting the paper<br />
• The abstract should not include graphics or tables<br />
• Papers should reflect the highest pr<strong>of</strong>essional standard<br />
• The use <strong>of</strong> trade names is discouraged<br />
CONTACT DETAILS<br />
If you would like to present an oral paper at the SCANZ<br />
conference 2012 please email your abstract, resumé and photo to:<br />
Sue Peck, SP Conference Management, Email: suepeck@xtra.co.nz,<br />
Phone: 64 6 3571466<br />
16 SURFACE COATINGS ASSOCIATION OF NEW ZEALAND<br />
SURFACE COATINGS ASSOCIATION NZ<br />
2012 CONFERENCE<br />
CALL FOR PAPERS<br />
In 2012 the <strong>Surface</strong> <strong>Coatings</strong> <strong>Association</strong><br />
<strong>of</strong> <strong>New</strong> Zealand will be hosting ‘Made<br />
in NZ’ in Blenheim, <strong>New</strong> Zealand. This is<br />
<strong>New</strong> Zealand’s leading technical event for<br />
the surface coatings industry attracting key<br />
participants from established and emerging<br />
companies.<br />
19-21 July 2012<br />
Marlborough Convention<br />
Centre, Blenheim<br />
KEY DATES<br />
Expressions <strong>of</strong> interest by: 31 <strong>October</strong> <strong>2011</strong><br />
Closing Date for Abstracts: 29 February 2012<br />
Final Paper Closing date: 31 May 2012<br />
Final Presentation Closing date: 30 June 2012
FRANK JOSEPH AITKEN-SMITH<br />
One <strong>of</strong> the hardest tasks in life is to write an obituary for a<br />
friend whom one has known for a great many years. Frank was a<br />
workmate and friend whose principles and integrity were <strong>of</strong> the<br />
highest order and he will be missed by friends and colleagues alike.<br />
Franks career in the Paint Industry started in 1947 when,<br />
using his own words, “I had no idea as to what I should do for<br />
a living other than it had to be in a laboratory”. He obtained<br />
a job with Fleetwood Paints in Deptford, South London and<br />
was introduced to the industry by an elderly chemist who was<br />
making paint in an equally elderly edge-runner. Varnishes were<br />
cooked in large mobile pots over sunken gas rings in an open<br />
lean-to attached to the <strong>of</strong>fice building. In Winter the varnish<br />
makers dressed in overcoats and scarves were carefully watching<br />
the “string” from the paddle.<br />
From here he moved on to Sherwood Paints in Barking, Essex<br />
when a tram, ferry and bus ride eventually got him to work<br />
each morning. Work was a large barn with a concrete floor and<br />
long wooden benches with nowhere to sit. Frank remarked “ in<br />
winter, with snow on the ground, we stood at our bench wearing<br />
overcoats and scarves under our lab coats” They did not make<br />
their own mill-bases as a man made them all on triple and single<br />
roll mills. Sherwood made a range <strong>of</strong> good decorative paints and<br />
Frank admitted he learned a good deal <strong>of</strong> his knowledge there.<br />
In about 1950 he joined Pinchin Johnson & Associates<br />
in Silvertown, a large modern paint factory with various<br />
sections dealing with Development, Raw Material Testing and<br />
Government Specification Training. He eventually obtained his<br />
A.R.I.C. with PJA. Frank always said that, at that time, they<br />
were expected to call their superiors “Sir” and to wear a suit and<br />
tie under their lab coats. Frank was very happy working for PJA<br />
but in 1953, for various reasons, he transferred to Taubmans<br />
Paints in Miramar, Wellington.<br />
His move to Wellington was significant as it was here in 1954<br />
he met and married Valerie, his wife, a partnership which was<br />
to last 57 years. Frank’s workmates were Jock Mandeno ( Willie<br />
Mandeno’s Father) and Keith Furneaux who was Frank’s Best<br />
Man at the wedding.<br />
Frank joined the O.C.C.A. N.Z. Section in 1953 a couple <strong>of</strong><br />
weeks after he joined the Taubmans lab.<br />
Two years later Frank was transferred to the Taubmans plant<br />
in Auckland and worked there until it closed down in 1959. He<br />
then joined Hill & Plumber on Federal and Hobson Streets<br />
when, although they were only a paint distributor, they purpose<br />
built a laboratory for Frank on its premises. Noel Frykberg was<br />
the Representative and identified customer needs while Frank<br />
formulated the necessary paints and sent it to Wellington where<br />
the paint was manufactured.<br />
Frank was also a Founder member <strong>of</strong> the Auckland Branch<br />
<strong>of</strong> the O.C.C.A N.Z. Section., and has maintained his<br />
20TH February 1930 - 21st August <strong>2011</strong><br />
membership throughout his career, being a regular attendee at<br />
Technical evenings, Past Chairman’s Dinners and Conferences<br />
etc. (Frank was Chairman <strong>of</strong> the Auckland Section between<br />
1963 and 1965)<br />
Noel then bought a company in Penrose Auckland with a<br />
nominee shareholder in David Levene and changed its name to<br />
Oregon Paints. The writer was the company chemist and the<br />
company eventually became Levene Paint Manufacturing Ltd.<br />
In 1962 Frank moved to B.I.P and, in 1970, to Goldex Paints,<br />
subsequently bought out by Samson Paints. When James<br />
Hardie bought Samson Paints, Frank retired - for the first time.<br />
In 1983 Frank joined the D.S.I.R. and worked at the Naval<br />
Dockyards Laboratory for the Dept. <strong>of</strong> Defence.<br />
Frank then joined Levene Paint Manufacturing in 1985 in a<br />
part-time position, which is where the Writer got to know and<br />
respect more <strong>of</strong> Frank, who became a very valued member <strong>of</strong> the<br />
L.P.M. Lab. Staff.<br />
In 1994 Frank retired for the second time, devoting his time to<br />
his own company.<br />
Way back in 1974 Frank and Valerie had started a company<br />
<strong>of</strong> their own called Fine Arts Supplies Ltd and expanded it to<br />
a very successful supplier <strong>of</strong> art paints when Bruce Clegg and<br />
Peter Ellis became involved. Frank subsequently sold his share<br />
in F.A.S. and formed Multicraft Manufacturing where, right<br />
up until his death, he and his associates were supplying photosensitive<br />
and screen blocking lacquers for screen printing as well<br />
as fabric dyes and chemicals.<br />
Frank was a humble man and it was very easy to underestimate<br />
his capabilities, which were enormous. Certainly <strong>of</strong> strong will,<br />
stubborn and forthright, he did not display his knowledge in an<br />
arrogant manner, rather he would quietly go on learning and not<br />
making the same mistakes twice. Frank is survived by his wife<br />
Valerie, his children and there families and a large number <strong>of</strong><br />
friends and colleagues.<br />
Tom Hackney<br />
SURFACE COATINGS ASSOCIATION OF NEW ZEALAND 17
SURFACE<br />
COATINGS<br />
ASSOCIATION<br />
NEW<br />
ZEALAND<br />
Seminar: 17th November <strong>2011</strong><br />
Venue: The University <strong>of</strong> Auckland, Tamaki Campus<br />
SCANZ is planning to run a full day seminar on basic paint parameters, similar<br />
to the very successful seminar a few years ago. This is aimed at new chemists<br />
and plant personnel with a penchant for understanding the chemistry behind<br />
their products. A degree in Chemistry is not essential.<br />
Provisional Program:<br />
• General introduction - what is paint ? Where and why it is used ?<br />
• HSNO – documentation, MSDS<br />
• Morning tea<br />
• Binders (resins / polymers)<br />
• Pigments<br />
• Solvents<br />
• Additives<br />
• Lunch<br />
• Paint Formulating<br />
• Rheology<br />
• Paint Production, processing<br />
• Afternoon tea<br />
• Quality / Paint Testing<br />
• Paint Defects / Trouble shooting<br />
Costs: These have not been finalised at print deadline but will be minimal to cover the<br />
overheads only. Further notice by email shortly.<br />
For more information or to express an interest, contact Phil Coveny on:<br />
Ph: 09 580 0851 Mob: 021 748 167 Email: philc@nuplex.co.nz.<br />
18 SURFACE COATINGS ASSOCIATION OF NEW ZEALAND<br />
Binders<br />
Rhodoline Defoamers<br />
Rhodoline Dispersants<br />
Extenders: Tixosil & Tixolex<br />
Upcoming Event<br />
The pr<strong>of</strong>essional body <strong>of</strong> chemists in the oil and chemical coatings industry<br />
Surfactants<br />
Water Repellents<br />
Wetting Agents<br />
Gensil Silicones<br />
<strong>New</strong> Zealand Manufacturer backed by Global Innovation<br />
For more information contact:<br />
Kevin Osten Ph (0274) 577 417 • kevin.osten@ap.rhodia.com • Customer Services: Ph (06) 368 9372 • Fax (06) 368 2071
Evonik Tego wins<br />
“Ringier Technology<br />
Innovation Award<br />
<strong>2011</strong> for <strong>Coatings</strong><br />
Industry”<br />
TEGO ® Twin 4100 is an innovative product that<br />
combines properties <strong>of</strong>ten seemingly contradicting<br />
in one molecule. This enables coating and ink<br />
customers to formulate environmentally friendly<br />
solutions by using an APE-free, solvent-free and<br />
isocyanate-free product. TEGO ® Twin 4100 is a good<br />
example <strong>of</strong> a product that Tego is utilizing based on<br />
its innovation technologies. This is exemplified not<br />
only by benchmarking existing technology but also<br />
by entering new chemical fields in the coatings and<br />
ink markets, especially in environmental friendly<br />
systems like water, UV and High Solids systems.<br />
Ringier Trade Media Ltd. is a leading B2B<br />
industrial information provider <strong>of</strong> technical<br />
information, solutions and applications for<br />
industrial leaders in China, Asia Pacific and the<br />
Middle East. The Ringier Technology Innovation<br />
Award is to recognize those who have made<br />
significant contributions for the advancement<br />
<strong>of</strong> the industry through technical innovation,<br />
productivity increase, economic efficiency and<br />
market opportunity creation. Ringier Technology<br />
Innovation Awards are regarded as one <strong>of</strong> the most<br />
important awards in China’s coating industry.<br />
David tells me that Twin 4100 ® is a Gemini<br />
surfactant that effectively lowers surface tension<br />
and improves wetting and flow even at very low<br />
concentrations. Its Gemini structure reduces<br />
foaming even in highly dynamic processes<br />
and application methods. The product’s good<br />
compatibility and long-term activity also impress<br />
in problematic binder systems. The solvent-free<br />
TEGO Twin 4100 ® has proven itself particularly in<br />
waterborne formulations for wood and industrial<br />
finishes as well as printing inks and lacquers …ED<br />
SITUATION WANTED<br />
Experienced coatings chemist seeks<br />
full time position at any coatings<br />
manufacturer in <strong>New</strong> Zealand.<br />
I am a qualified paint chemist from Zimbabwe with<br />
vast knowledge and technical expertise in paint<br />
systems, formulations and production mechanisms.<br />
I hold Bachelor’s degree (honours) in chemistry<br />
and South Africa Paint Technology course and have<br />
received four awards for being the best student.<br />
In 2010 I received the ‘Kekwick Award’ for being<br />
the most outstanding student during the Paint<br />
Technology course, presented to me by Brenda<br />
Peters the Oil & Colour Chemists <strong>Association</strong><br />
(OCCA) President <strong>of</strong> which I am a member <strong>of</strong>.<br />
I have 5 years experience in the coatings industry<br />
and have knowledge with domestic, industrial and<br />
automotive coatings. My duties and responsibilities<br />
involve the following:<br />
Research and development on new products,<br />
Formulation optimization, in process control <strong>of</strong><br />
unfinished and finished paint in production, Quality<br />
control <strong>of</strong> incoming raw materials, evaluating<br />
competitors’ products, Offering technical assistance<br />
to internal and external customers, customer<br />
complaints resolution.<br />
Contact: Patience Sameke Email: patiek8@gmail.com<br />
Cell: +263 772747301<br />
SURFACE COATINGS ASSOCIATION OF NEW ZEALAND 19
Random and Disordered Thoughts - By Jetsam<br />
Once again we are blessed with a wonderful article by Peter<br />
Walters tracing the history <strong>of</strong> perhaps our most important<br />
single paint ingredient, certainly our most important white<br />
pigment in the modern age.<br />
When you look back at things like white lead, one is able to<br />
imagine that white paint, or even orange paint, was a toxic<br />
nasty that could poison us and make us all sterile. A bit like the<br />
ancient Romans with their lead water pipes. Titanium dioxide<br />
is completely the opposite, a potential environmental life saver.<br />
We have even been sent an article that extols the virtues <strong>of</strong><br />
cleaning the atmosphere using nano-sized titanium dioxide.<br />
In this age <strong>of</strong> global warming and carbon tax, I note that<br />
the scientific community has determined that growing trees<br />
is contributing more to global warming because <strong>of</strong> the dark<br />
colour than the benefit from adsorbing carbon dioxide. Maybe<br />
our government could fund research into growing white trees.<br />
IMCD <strong>New</strong> Zealand Ltd is a leading supplier <strong>of</strong> specialty and commodity chemicals into the<br />
<strong>New</strong> Zealand <strong>Coatings</strong>, Inks, Construction, Adhesive and related markets.<br />
Some <strong>of</strong> our key agencies include…<br />
Dow Chemicals - Glycols, Epoxy resins, Glycol Ethers,<br />
Amines, PEGs, Surfactants and Water Treatment systems.<br />
Troy - Wet/Dry film Biocides and Additives.<br />
AkzoNobel - Organic Peroxides.<br />
Sasol - Surfactants and Olefins.<br />
20 SURFACE COATINGS ASSOCIATION OF NEW ZEALAND<br />
That raises the question <strong>of</strong> white houses with white ro<strong>of</strong>s. Some<br />
scientists worked out the positive contribution to climate cooling<br />
if every ro<strong>of</strong> was painted white.<br />
But there are a growing number <strong>of</strong> local bodies, or the<br />
remnants <strong>of</strong> them if you live in Auckland, that are specifying<br />
light reflectance values <strong>of</strong> no more than 55%, medium to<br />
dark coloured houses with, presumably, correspondingly dark<br />
coloured ro<strong>of</strong>s. With the huge potential <strong>of</strong> titanium dioxide to<br />
save the planet, or at least us from ourselves more likely, you<br />
have to wonder about the commitment or the intelligence <strong>of</strong><br />
the politicians that make up these rules, or are they just paying<br />
lip service to global warming? After all, carbon is easy to tax<br />
and as we all seem to have forgotten in the euphoria <strong>of</strong> the<br />
rugby world cup, so are people.<br />
I bet most <strong>of</strong> you did not realise how political titanium<br />
dioxide really is.<br />
DuPont - Capstone Fluoro-Additives and Micro Powders.<br />
Wacker - EVA Polymer Emulsions and Powders,<br />
Silicones, Silanes, Siloxanes and Fumed Silica.<br />
<strong>New</strong> Supplier: http://www.dow.com/ Eagle Chemicals - Solvent based<br />
resins (Alkyds, Polyester and Acrylics).<br />
RECREATE PMS<br />
Our contact details:<br />
Paul Armistead and Warren Strickett • 09 582 0250 • imcdcs@imcd.co.nz • www.imcd.co.nz<br />
Head Office<br />
5 Lockhart Place, Mt Wellington, Auckland 1060, <strong>New</strong> Zealand<br />
P.O. Box 62274, Mt Wellington, Auckland 1641, <strong>New</strong> Zealand<br />
Tel +64 9 914 7010 Fax +64 9 914 7014<br />
Email: sibelconz@sibelco.co.nz<br />
Nationwide Stockists <strong>of</strong>: Barytes, Calcite, Cement, Clay, Diatomaceous Earth,<br />
Feldspar, Gypsum, Iron Oxide Pigment, Magnesium Oxide, Mica, Miclay,<br />
Nepheline Syenite, Pumice, Pyrophyllite, Silica, Slate, Talc & Wollastonite<br />
www.sibelco.co.nz
Rohm and Haas <strong>New</strong> Zealand Ltd<br />
• Paraloid ® Thermoplastic/Thermosetting<br />
Acrylics<br />
• Primal ® Acrylic Copolymers<br />
• Acrysol ® , Orotan ® , Kathon ® , Ropaque ® ,<br />
Skane ® , Rocima ® , Additives<br />
• Acumer ® , Acusol® Dispersants/Detergent<br />
Polymers<br />
Rhodia<br />
• Rhodoline ® Defoamers, Dispersants, Wetting<br />
Agents<br />
• Abex ® , Alkamuls ® , Antarox ® , Geropon ® ,<br />
Igepal ® , Rhodasurf ® , Soprophor ® Surfactants<br />
“TECHNOLOGY AND COLOURS<br />
FOR COATINGS”<br />
• Organic /Inorganic Pigments (DIC, Sudarshan, Sun E.C. Pigments)<br />
• Fiesta Fluorescent Colours (Swada, NovaGlo, Glowbug)<br />
• Ultramarine Pigments<br />
• Gasil Matting Silicas, Silica gels, Freeflow (PQ Corp)<br />
• Pigment Dispersions (DIC Group)<br />
• Coating & Composite Resins (Reichhold & DIC Group)<br />
• Epoxy Curing Agents/Resins (Reichhold & DIC Group)<br />
• Polyisocyanates/Polyurethanes (Reichhold & DIC Group)<br />
• Aluminium Pastes/Powder (Benda Lutz)<br />
• Solvent Dyes (Rathi)<br />
DIC <strong>New</strong> Zealand<br />
PO Box 12-748, Penrose, Auckland 1642<br />
Telephone 09 636 2947 • Fax 09 636 5522<br />
email: penny.meads@dic.co.nz • website: www.dic.co.nz<br />
CONNELL BROS COMPANY AUSTRALASIA LIMITED<br />
(formerly Wilbur-Ellis Connell Bros)<br />
3rd Floor, 19 Great South Road, <strong>New</strong>market, Auckland<br />
PO Box 9956, <strong>New</strong>market, Auckland<br />
( +64 9 984 4700 7 +64 9 921 3391<br />
www.connellbros.com<br />
Aditya Birla Chemicals<br />
• Epotec ® Epoxy Resins, Reactive Diluents &<br />
Curatives<br />
Columbian Chemicals Company<br />
• Raven ® Carbon Black Pigments<br />
Dynasol<br />
• Calprene ® and Solprene ® Elastomers<br />
Huber Engineered Materials<br />
• Calcium carbonate, Silica/silicate, Kaolin<br />
clay, Alumina trihydrate, Barium sulphate,<br />
Engineered composites<br />
General Chemicals<br />
• Glycols, Coalescents, D-Limonene, EDTA, Iron<br />
Oxides, Surfactants, Hot Polymerised SBR<br />
Rubbers, Various Commodities<br />
AArbor International Corporation<br />
• Silverking ® Aluminium Pigment Pastes<br />
Alberdingk Boley Gmbh<br />
• Refined Linseed Oils<br />
Sherwin Williams Chemicals<br />
• Moly-White ® Corrosion Inhibitors<br />
Bayer <strong>New</strong> Zealand Ltd<br />
PO Box 2825<br />
Auckland<br />
Phone 64 9 441 8595<br />
www.lanxess.com
• Alkyd Resins<br />
• Polyester Polyols<br />
• Solution Acrylics<br />
• Polyester Gelcoats<br />
I N D U S T R<br />
I E S<br />
Manufacturers & Suppliers <strong>of</strong>:<br />
L I M I T E D<br />
• Aqueous Polymer<br />
Dispersions<br />
• Polyurethane Dispersions<br />
• M/C Urethanes<br />
Proud<br />
Supporters<br />
<strong>of</strong> SCANZ<br />
• Waterborne Alkyds<br />
• T RAcrylic/Alkyd<br />
I E S L I M I T E D Hybrid Resins<br />
• Speciality Resins<br />
• Acrylic Polyols<br />
P O Box 12-841, Penrose, Auckland. Phone: 0-9-579 2029. Fax: 0-9-571 0542. Toll Free: 0800 803 000<br />
T h e<br />
QC<br />
Building the Future Together<br />
W o r l d o f A d d i t i v e s<br />
Proud supporter <strong>of</strong> SCANZ<br />
Solution<br />
s for<br />
<strong>Coatings</strong><br />
and<br />
Plastics<br />
C o o k s C o m p o s i t e s<br />
Tronox Titanium Dioxide<br />
Nubiola anti-corrosives, ultramarine blue<br />
Shamrock micronised waxes<br />
Dynoadd coatings additives<br />
Microbeads surface modifiers<br />
Industrial Copolymers resins and Oxazolidines<br />
Jayant Oil Castor oil and derivatives<br />
Nippon Polyurethane<br />
Worlee Chemie resins<br />
Spolchemie Epoxies<br />
Silanes, chlorinated paraffins, zinc oxide<br />
Organic pigments and lead chrome replacements<br />
Iron oxide, talc, barium sulphate, silica flour, mica<br />
Metal powders and pastes, pigment preparations<br />
D-Limonene, methylene chloride, caustic soda<br />
Building Building the Future the Future Together Together<br />
T h e<br />
Contact: Heather Smith, Richard Calvin, Dave Perano, Steve Parlane,<br />
John Gilbert, Sean Winter, Michael Behr, Anne Day, Tracy Taylor,<br />
Taryn Rabie, Gray Gilbert<br />
Ph (09) 486 6637 • Fax (09) 486 6286<br />
www.rebain.com<br />
Offices in Auckland, Palmerston North, Melbourne, Barcelona, Rotterdam & Venezuela<br />
T h e W o r l d o f A d d i t i v e s<br />
W o r l d o f A d d i t i v e s<br />
QC<br />
Solution<br />
s for<br />
<strong>Coatings</strong><br />
and<br />
Plastics<br />
& P<br />
Q<br />
o<br />
C<br />
l<br />
S<br />
y<br />
o<br />
m<br />
lu<br />
e<br />
tio<br />
r<br />
n<br />
s<br />
s for<br />
<strong>Coatings</strong><br />
and<br />
Plastics<br />
Supplier <strong>of</strong> brand Titanium Dioxide<br />
I N D U S<br />
I N D U S T R I E S L I M I T E D<br />
C o o k s C o m p o s i t e s & P o l y m e r s<br />
C o o k s C o m p o s i t e s & P o l y m e r s<br />
PO Box 5175<br />
Rotorua West, Rotorua 3044<br />
Toll Free NZ only:<br />
0800 4 TIONA (0800 484 662)<br />
Phone +64 7 346 2225<br />
Fax +64 7 346 2224<br />
Mobile: 021 643 192<br />
www.cristalglobal.com