Green Technologies for the Leather Production- Clariant - CLRI

lConfidential 

Global Bu Leather Leather Services Business 

Head of Marketing & Sales 

Harald Bauer 

07.09.2010 

Green Technologies for the Leather 

Production 

45th Leather Research Industry Get Together (LERIG) 

29 January 2011 

Agenda 

Ecological Leather Production 

Ecological Update 

Tanning 

Retanning, Fatliquoring 

Finishing 

BU Leather Services, Harald Bauer, Global Head of Markeing & Sales (Copyright Clariant. All rights reserved.) Slide 2 

1

Green Leather – Industry Achievements 

in the Past 

Wet White tanning as alternative to Chrome tanning 

Enzymatic Unhairing process 

Continous improvement of chemical exhaustion for the beamhouse, tanning and wet end processes 

Complete waterborne finishing replacing solvent systems or solvent/water emulsions 

Replacement of hazardous substances (Nonylphenols, Phthalates, Ethylglycol, Dimethylformamide, 

cancerogenic azo dyes and aromatic amines, lead chromate pigments, short chain chloro paraffins) 

Development of Upgrading technologies for improved raw hide utilization 

Continuous chemical reduction in finishing (low pressure spraying, RRC technology) 


Stakeholder for the Leather – 

Manufacturing Process 

Economy 

Environment 

Clariant 

Technical Balance 

Support 

Customer 

Demand 

High Yield – Low Resources 

• Minimizing Water quantity 

• Minimizing chemical demand 

• Minimal chemical and water waste 

• Minimal leather waste 

• Maximizing leather yield 

High Speed – Low Cost 

• Lowest production costs 

• Production speed 

• Highest production yield 

• Lowest waste 

• Lowest chemical and water consumption 

High Quality – Low Cost 

• Leather Quality 

• Lowest possible cost 

• Lowest possible risk (hazardous substances) 

• Fashion, Function 

• Wearing comfort 


2

Green Leather – New Ecological 

Demands 

Chemicals 

Green chemistry in leather chemicals 

Safety 

Environmental friendly substances, reduction of hazardous substances 

Waste 

Raw 

material 

Updated leather production with minimized waste and resources 

Further development of the manufacturing process with maximizing the 

raw material 


Green Leather – Examples for new 

achievements 

Water/salt 

reduction 

Process Innovation – New Wet White Tanning Technology 

Chemicals 

Greener Fatliquors and Retanning Agents 

VOC 

NMP free Finishing systems 

Yield 

Modern Upgrading Technologies 


3

Agenda 



Tanning 


Finishing 


Most commonly used mineral free tanning 

systems 

Phosphonium salts 

Glutaraldehyde 

Vegetable 

Replacement Syntans 

Oxazolidine 

Metal free Tanning 

Systems 

Silicates 

Oxidisable oil tannage 


4

Why Granofin ® Easy F-90? 

Increasing 

demand 

for chrome-free 

Leather 

Environment perspective 

Production perspective 

Process 

simplification 

Increasing 

ecological 

demand 

EasyWhite Tan 

Cost reduction 

Operator 

safety 

Environmental 

awareness 

Less scope 

for processing 

errors 


EasyWhite Tan & Wet White comparison 

Wet White 

Chemical 

Time 

min 

Offer 

in Kg 

Process % 

Pickle 40 Water 8000 

7 Salt 15 1400 

Add 1 Formic Acid 85% 45 200 

Add 0,6 Sulphuric Acid 98% 120 120 

Tanning 2,7 Glutaraldehyde (25%) 480 540 

Basifi. 0,3 Sodium Bicarbonate 20 60 

Add 0,3 Sodium Bicarbonate 20 60 



Add 3 Phenol Syntan p. 60 600 

Total 880 3060 

EasyWhite Tan 

Chemical 

Time 

min 

Offer 

in Kg 

Process % 

Tanning 30 Water 6000 

10 Granofin F-90 liq 480 2000 

Total 480 2000 

Wet White 

1 2 3 4 5 

Bate 

Pickle Tanning Basification Effluent 

Deliming 

Process considered for the comparison 

EasyWhite 

Tan 

1 2 3 

Bate 

Tanning 

Deliming 

Effluent 


5

Key Points in the Process 

I 

Start pH 8,5 to 7,0 after bating 

II Temperature 25°C to 30°C 

III Product offer 8% to 10% based on limed /split weight 

IV Running time 8 to 12 hours 

V Increase temperature after 60-90 min to 30 -35°C 

VI Increase temperature after 90-120 min to 40°C 

pH 

8 

7 

6 

5 

4 

3 

2 

pH 

New Process with Granofin Easy F90 8 

7 

6 

5 

Standard Process 

4 

3 

2 

VII Run 6 to 8 hours at 40°C 

VIII End pH 4,5 to 5,4 

1 

1 

0 

0 

Time 

0 1 2 3 4 5 6 7 8 9 10 

IX Shrinkage temperature 72°C to 75°C 


Customer Benefits through EasyWhiteTan 

(Granofin ® Easy F-90) 

Process focus EasyWhiteTan 

Deliming and bating 

(~ 4 h / 1 Check) 

Pickle 

(~ 2-4 h / 2-3 Checks) 

Tanning 

(~ 8-12 h / 1 Check) 

Basification 

(~ 2-3 h / 2 Checks) 

Deliming and Bating 

(~ 4-6 h / 1 Check) 

New compact process– no pickle necessary 

(~ 8-12 h / 2 Checks) 

Environmentally friendly 

Lean production process 

Less use of chemicals 

Reduction of production time 

More consistent production quality 

Less scope for processing errors 


6

Leather Properties 

Wet 

White 

Crust 

• Excellent grain flatness 

• White appearance 

• Very tight grain 

• Less neck wrinkles 

• Good resistance to mould 

• Shrinkage temperature ~72 C 

• Cationic Character of Wet White 

• Suitable for shoe upper and fancy leathers, not only for Automotive and Furniture 

• More accurate substance control, compare to Glutaraldehyde and THPS 

• Less stretch and elasticity 

• Less wrinkles, flatter growths marks 

• High Whiteness if required 

• Very tight grain 

• Wide range of articles possible 

• Combinable with metal retanning if necessary (chrome, aluminum or zirconium) 


Conclusion 

• The technological application of Granofin® Easy 

F-90 permits a simplification of the current known 

processes 

• Granofin® Easy F-90 technology is an 

environmentally friendly tanning system 

• Granofin® Easy F-90 is already in production and 

being tested at several customers 

– All potential applications not yet evaluated 

– Further work on optimization of retanning 

process – Principal to reduce products used 

compare to current production 

– Evaluation of products development for the 

retanning of EasyWhite Tan 

– Results to date extremely promising 

EasyWhite Tan 

opens new 

horizons 


7

Agenda 



Tanning 


Finishing 


Retanning Agents – Ecological Update 

Retanning 

Agent 

Synthanes 

Chemistry 

• Aromatic base (Phenol, 

Naphthalene, cresol etc.) with 

sulphonate or hydroxy function 

• Formaldehyde condensation 

Eco Target 

• Residual content of Formaldehyde 

and Phenol of both < 50 ppm 

Resins 

• Urea-Formaldehyde 

• Dicyandiamide-Formaldehyde 

• Melamine-Formaldehyde 

• Residual content of Formaldehyde 

< 50 ppm 

Polymeric 

• Polyacrylic acid 

• Combination and copolymerisation 

with natural substances 

• Incorporation of renewable (and 

biodegradable) raw materials 

• Tergotan PMB 


8

Fatliquors – Ecological Update 

Fatliquors 

Natural 

Chemistry 

• Sulfated or sulfited natural oils 

(castor, neatsfoot, soya) 

Eco Target 

• Long term experience in using 

natural oils 

• Recovered natural oils 

Synthetic 

• Alkylsulfosuccinates 

• Quaternary amines as cationic 

fatliquors 

• Use of by-products as raw materials 

• Higher exhaustion, lower COD 

values for the waste water 

Polymeric 

• Polymeric succinates and 

sulfosuccinates 

• Reuse of synthesis waste as raw 

materials 

• Higher exhaustion, lower COD 

values for the waste water 

• Tergotan PO-60 


Agenda 



Tanning 


Finishing 


9

NMP-free Finishing 

VOC 

- volatile organic compounds - 

Definition 

Europe 

Definition 

USA 

• EC Directive 1999/13/EC 

- Vapour pressure at 20 C (or at working temperature) over 

0.1 hPa 

• CFR 40, Part 51.100(s), US EPA 

- chemical compounds that take part in photochemical 

reactions in the atmosphere 

• Legislators reducing and making emissions more expensive 

‣ Continuous VOC reduction for all processors 

‣ Continuous VOC reduction for all (finishing) chemicals 


10

NMP and VOC 

Boiling point 

at normal pressure 

Vapour 

pressure* 

Ethanol 78 C 79 hPa 

Water 100 C 32 hPa 

Butyl acetate 125 C 17 hPa 

Butyl glycol 171 C 1.5 hPa 

NMP 202 C 0.4 hPa 

VOC (EU) 

> 0.1 hPa 

Ethylene glycol 197 C < 0.1 hPa 

* CRC Handbook of Chemistry And Physics 

NMP is a VOC according to EU and US definitions 


NMP – N-methylpyrrolidone – 

Properties 

Chemically stable 

Polar solvent – Completely soluble in water 

O 

Good miscibility with organic compounds 

Aprotic – No reaction with isocyanate 

Reduces surface tension 

pH-neutral 

N 

CH 3 


11

Production process 

Acetone vs. Prepolymer ionomer process 

A) Acetone process 

first 

reaction 

step 

dispersion 

with 

water 

second 

reaction 

step, 

distillation 

monomers 

in solvent 

prepolymer 

in solvent 

prepolymer dispersion 

containing solvent 

solvent free 

polymer dispersion 

B) Prepolymer ionomer process 

first 

reaction 

step 

dispersion 

in 

water 

second 

reaction 

step 

monomers 

with NMP 

prepolymer 

with NMP 

prepolymer dispersion 

containing NMP 

polymer dispersion 

containing NMP 


NMP as a coalescing agent 

Miscible with water and many solvents 

Water evaporates 

Primary dispersion 

Reduces the MFT 

Improves flow 

Simplifies film formation 

Deformation of the 

polymer particles 

Interdiffusion 

Packing of spheres 

Packing of rhombic 

dodecahedrons 

Coalescing agent 

promotes interdiffusion 

and dissolution 

of boundary surfaces 

Film 


12

NMP in leather 

Partial dissolution of lipophilic substances 

DT 

H 2 O 

H 2 O 

NMP 

Greasing agents 

Retanning agents 

Dyestuffs 

(Hydro)thermal processes in the 

finished leather 

• Natural ageing processes 

• Artificial ageing test 

• Migration into the crust 

• Partial dissolution of watersoluble 

and, above all, lipidsoluble 

substances 

• Promotion of migration to 

the (finished) surface 


New procedure for NMP-free 

polyurethane dispersion 

Water 

Polyol 

Finished PUR 

dispersion 

Isocyanate 

Auxiliary agent 


13

NMP – Legal developments and measures 

taken by Clariant 

International legislation 

2001 2003 2004 2005 … 2010 

Addition of NMP 

in California 2001 to 

Proposition 65 

EU resolution to 

reclassify NMP 

End of the 

transitional 

period Binding 

EU classification 

Clariant 

Future 

Project start 

Oct 2001 

Binding agent syntheses 

without NMP 

1 st generation 

Feb 2004 

Complete NMP-free 

finishes 

Standard 

products 

Apr 2005 

All standard products 

are NMP free 

>2010 

Further reductions in VOCs 


Topcoats – Highest performance 

without NMP 

Application 

• Application process 

• Process parameters (Flow, viscosity) 

Fastness 

Aesthetics 

and haptics 

• Wear properties 

• Ageing resistance 

• Soilability 

• Squeaking behaviour 

• Cracked grain 

• Matt / Gloss grade 

• Depth of black 

• Feel 

No difference 

between NMPcontaining 

and 

modern lacquers! 


14

NMP and VOC content 

- Priming- 

Priming (example recipe) 

2002 Amount NMP VOC EU Since 2005 Amount NMP VOC EU VOC USA 

PU binder 300 g 5.2% 6.0% PU binder 300 g 0.0% 0.0% 0.5% 

Soft PU 50 g 4.7% 8.3% Soft PU 50 g 0.0% 3.5% 4.0% 

Acrylate 100 g 0.0% 0.0% Acrylate 100 g 0.0% 0.0% 0.0% 

Pigment 100 g 0.0% 0.0% Pigment 100 g 0.0% 0.0% 0.0% 

Matting paste 120 g 0.0% 0.6% Matting paste 120 g 0.0% 0.6% 0.6% 

Additive 70 g 0.0% 0.0% Additive 70 g 0.0% 0.0% 0.0% 

Wax 30 g 0.0% 0.0% Wax 30 g 0.0% 0.0% 0.2% 

Water 230 g Water 230 g 

Total 1000 g 1.8% 2.3% Total 1000 g 0.0% 0.2% 0.4% 


NMP and VOC content 

- TopCoat - 

TopCoat (Example recipe) 

2002 Amount NMP VOC EU Since 2005 Amount NMP VOC EU VOC USA 

Matting 400 g 7.1% 15.0% Matting 400 g 0.0% 6.3% 6.5% 

PU gloss binder 100 g 5.2% 6.0% PU gloss binder 100 g 0.0% 0.0% 0.5% 

PU gloss binder 2 80 g 7.0% 8.0% PU gloss binder 2 80 g 0.0% 1.8% 2.3% 

Silicon old 60 g 0.0% 35.0% Silicon new 60 g 0.0% 20.0% 21.0% 

Isocyanate 60 g 0.0% 20.0% Isocyanate 60 g 0.0% 20.0% 19.8% 

Water 300 g Water 300 g 

Total 1000 g 3.9% 10.5% Total 1000 g 0.0% 5.1% 5.3% 


15

Summary 

• NMP-free products and finishing systems available with 

the same performance 

• Long-term usability of NMP-related substances is 

questionable 

• Reduction in NMP is not sufficient to meet car and 

furniture manufacturers‘ specifications 

• Elimination of NMP succeeded with concomitant 

sustainable VOC reduction 

By VOC reduction and NMP Elimination sets a new 

ecological standard in finishing 


Upgrading 

16

Upgrading 

Economic Need meets Ecological Benefit 

Rawhide Quality available 

high 

Yield Improvement 

Upgrading 

Cutting waste reduction 

Resource optimization 

low 

1980 2011 

Demand of Premium Leather 


Upgrading 

Polishing Grounds 

• Upgrading of leather with minor grain defects 

• Maintaining the natural look, low overloading of the grain 

• For RRC and spray finishes 

• For full grain and corrected grain 

• Ironing or polishing, no buffing necessary 

• Prebase for 

– Shoe upper 

– Furniture 

– Garment 

– Fancy Goods 


17

Upgrading 

Microsphere Technology 

RRC Technology 

Improvement of filling power and adhesion 

Optimized stability at the blade/knife 

New product: Melio 06-U-78 


Upgrading 

Further developments 

• Strong covering systems without hardening effects of 

classical fillers 

• Improved embossing behaviour 

• Mechanical and optical properties of binder and filling 

materials coming closer 

• Filler-Binder Hybrids 

New Technologies 


18

lConfidential 

Global Bu Leather Leather Services Business 

Head of Marketing & Sales 

Harald Bauer 

23.01.2011 

Thank you very much for your 

attention 

19

Green Technologies for the Leather Production- Clariant - CLRI

Create successful ePaper yourself

Delete template?

Save as template?