Multifunctional propyleneimines-new generation of crosslinkers for ...

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Z. Czech / International Journal of Adhesion & Adhesives 24 (2004) 503–511 509
cohesion (N) at 20˚C and 70˚C
120
100
80
60
40
20
0
20˚C
70˚C
TMTT
TPAA
TMTT
TPAA
0.1 0.2 0.3 0.4 0.5
propyleneimine amount (wt.%)
Fig. 29. Cohesion dependence of propyleneimine content.
tack, adhesion and cohesion. The increase of crosslinkers
concentration from0.1 to 0.5 wt% decreases the
tack and adhesion performance by factor about 3–4 in
comparison to initial value. The best cohesion was
achieved with 2,4,6-tris(1-methylaziridinyl)-1,3,5-triazine
(tripropylenemelamine) (TMTT).
CH 3
N
N P O
CH 3
N
CH 3
Fig. 30. Tris-(1-(2-methylaziridynyl)phosphinoxide (MAPO).
S
N P N
CH 3 CH 3
N
CH 3
Fig. 31. Tris-1-(2-methyl)aziridinylphosphinesulfide (TAPS).
O
3.4. Influence of propyleneimines with central heteroatom
on tack, adhesion and cohesion
P
N
N
CH 3
Mainly phosphorus and sulfur serve as heteroatoms
(Figs. 30–32).
Performance qualities of the investigated propyleneimine
crosslinking agents with central heteroatom on
tack, adhesion and cohesion of acrylic PSAs are
described in Figs. 33–35.
The increase of propyleneimine crosslinker concentration
containing central heteroatomdecrease the peel
properties such as tack and adhesion and increase of
course the cohesion at 20 C and 70 C. The best
cohesion and also the low tack and adhesion were
achieved with tris-1-(2-methyl)aziridinylphosphinesulfide
(TAPS). In general, it can be said that the use of
propyleneimines as crosslinker with P¼S group gave the
better cohesion that the use of propyleneimines with
P¼O group.
3.5. Reaction products from multifunctional acrylates
and propyleneimine
Some classical compounds of this section are shown in
Ref. [16]. The table below comprises the characteristics
of propyleneimine crosslikners being offered in the
market (Table 1).
These three crosslinkers have been compared by using
a synthesized polyacrylate PSA at a coating weight of
60 g/m 2 on polyester foil. The performance of crosslinked
pressure sensitive adhesives are presented in
Table 2.
tack (N)
CH 3
Fig. 32. N,N 0 -Bis-propanephosphonic acid diamide (BPAD).
16
12
8
4
0
BPAD
MAPO
TAPS
0.1 0.2 0.3 0.4 0.5
propyleneimine amount (wt.%)
Fig. 33. Tack dependence of propyleneimine content.
As can be seen fromthe Table 2, Permutex XR-2500
is a more useful crosslinker than Trazidin VN and
Neocryl CX-100. While the cohesion of crosslinked
PSAs is comparrable for the both crosslinkers
Permutex XR-2500 and Trazidin VN, the tack and
adhesion tested at 20 C and 70 C are higher in the case
of Permutex XR-2500 introduction. As shown Permutex
XR-2500 provides high-quality crosslinked polyacrylic
PSAs.