 |
|
Low fogging HR foams
(TDI) |
| Home |
|
HR foams can significantly contribute to fogging of windshields in
cars. The use of low volatility components such as surfactants,
catalysts is important to reduce fogging. Either high molecular
weight additives or additives with functional groups can be used to
achieve no-fogging. |
|
Increase in the crosslinking density of the urea hard segment is
important to improvement in recovery and good compression set. Either
diethanolamine or polyfunctional isocyanates can be used to increase
crosslinking. Increasing the crosslinking density of the soft phase
(higher functional polyols) will reduce the elongation. The resulting
increase in chain entanglements reduces the mobility and increases the
recovery time.
|
|
For increased in rigidity of these foams higher density foams using
MDI as a diisocyanate have been developed.
|
|
|
Formulation HR Foam Carbon dioxide blown
|
Fogging Amine |
|
Non-fogging Amine |
|
|
Polyether
styrene modified OH # 30 |
100 |
|
100 |
|
Diethanolamine,
CAS # 111-42-2 |
1.6 |
|
1.6 |
|
Low fogging
silicone surfactant |
1 |
|
1 |
|
Water |
3.2 |
|
3.2 |
|
Triethylenediamine
33 %, CAS # 280-57-9 |
0.24 |
|
|
|
Hydroxypropylimidazole,
CAS # 37788-55-9 |
|
|
0.35 |
|
Bis(dimethylamino)ether
formic acid, CAS # 51390-19-3 |
0.24 |
|
|
|
Bis(dimethylamino)
2-hydroxpropanol, CAS # 5966-51-8 |
|
|
0.40 |
|
TDI 80,
80 % 2,4-TDI; 20 % 2,6-TDI, CAS # 26471-62-5 |
40.7 |
|
40.7 |
|
Isocyanate
index |
105 |
|
105 |
|
Test results of machine prepared foam
(test
methods) (Conversion factors)
|
|
|
|
Overall density kg/m3 ( lb/ft3),
(1 kg/m3 =
0.0624 lb/ft3
) |
43.6(2.72) |
|
43.7(2.73) |
|
Core density kg/m3 |
40.9(2.55) |
|
39.7(2.45) |
|
SAG factor |
2.7 |
|
2.7 |
|
CLD 40* |
4.2 |
|
4.5 |
|
CLD at 40 density |
4 |
|
4.6 |
|
Compression set
50 % |
4 |
|
4 |
|
Compression set
70 % |
8 |
|
|
|
HACS % |
13 |
|
35 |
Tear strenght
N/m |
245 |
|
220 |
Tensile strength
kPa (1 kPa = 0.145
PSI) |
165 |
|
150 |
|
Resilience |
64 |
|
65 |
|
Air flow |
103 |
|
103 |
|
|
|
|
|
|
Fogging |
|
|
|
|
Silicone ppm |
400 |
|
350 |
|
Amine ppm |
300 |
|
<5 |
|
|
|
|
|
|
*CLD 40 corrected for foam density using formula
CLD1 = CLD2*(r1/r2)2 |
|
|
|
|
|
Last edited on:
|
November 16, 2006
|
Copyright®, Design, Layout and Technical Content by:
|
|
|
|
|