Flexible foams comprising additives for improving hardness
A polyurethane foam-forming composition comprising a polyether functional silicone additive with an active hydrogen atom. The addition of the polyether functional silicone additive to a foam-forming composition for a flexible foam increases the hardness of the resulting foam without adversely affecting other properties of the foam.
1 . A flexible polyurethane foam-forming composition comprising:
(a) a polyol;
(b) a polyisocyanate comprising toluene diisocyanate, the polyisocyanate having an isocyanate index of from about 70 to about 120;
(c) a catalyst selected from an organotin catalyst;
(d) a surfactant other than a polyether functional silicone (e); and
(e) a polyether functional silicone of the formula:
M*D x D″ y M*
where:
M* is R a (CH 3 ) 3-a SiO 1/2
D is (CH 3 ) 2 SiO 2/2
D″ is (CH 3 )(R)SiO 2/2
x is 1-100;
y is 1-20
a is 0 or 1;
R is polyether substituent C n H 2n O(C 2 H 4 O) b (C 3 H 6 O) c R 1 derived from a single type of polyether substituent, where R 1 is —H, —R 3 N(H)R 2 , or —R 3 SH, R 2 is H or a C1-C10 alkyl, R 3 is C1-C10 alkylene; n is 3 to 4; b is a number such that the ethylene oxide residues constitute from about 30% to about 100% by weight of the alkylene oxide residues of the polyether substituent R; c is a number such that the propylene oxide residues constitute from about 0% to about 70% by weight of the alkylene oxide residues of the polyether substituent R; and the substituent R has a number average molecular weight of from about 200 Dalton to about 5000 Dalton, with the proviso that the flexible polyurethane foam-forming composition is free of a physical blowing agent except that the composition may optionally comprise carbon dioxide or methylene chloride, and wherein a foam produced from the composition is a flexible polyurethane foam.
2 . The flexible polyurethane foam-forming composition of claim 1 , wherein b in polyether functional silicone (e) is such that the ethylene oxide residues constitute from about 35% to about 100% by weight of the alkylene oxide residues of the polyether substituent R.
3 . The flexible polyurethane foam-forming composition of claim 1 , wherein b in polyether functional silicone (e) is such that the ethylene oxide residues constitute from about 40% to about 100% by weight of the alkylene oxide residues of the polyether substituent R.
4 . The flexible polyurethane foam-forming composition of claim 1 , wherein the polyether substituent R of the polyether functional silicone (e) has an ethylene oxide residue content of from about 70% to about 100% by weight.
5 . The flexible polyurethane foam-forming composition of claim 1 , wherein b of the polyether functional silicone (e) is such that the ethylene oxide residues constitute from about 75% to about 95% by weight of the alkylene oxide residues of the polyether substituent R.
6 . The flexible polyurethane foam-forming composition of claim 1 , wherein R 1 in the polyether functional silicone (e) is —H.
7 . The flexible polyurethane foam-forming composition of claim 1 , wherein the polyether substituent R of the polyether functional silicone (e) is a polyether substituent having a number average molecular weight of from about 400 Dalton to about 4000 Dalton.
8 . The flexible polyurethane foam-forming composition of claim 1 , wherein R in the polyether functional silicone (e) has a number average molecular weight of from about 500 Dalton to about 1500 Dalton.
9 . The flexible polyurethane foam-forming composition of claim 1 , wherein y in the polyether functional silicone (e) is 2-20.
10 . The flexible polyurethane foam-forming composition of claim 1 , wherein y in polyether functional silicone (e) is 1-10.
11 . The flexible polyurethane foam-forming composition of claim 1 , wherein the polyether functional silicone (e) is present in an amount of from about 0.1 to about 10 parts by weight based on the total weight of the flexible polyurethane foam-forming composition.
12 . A flexible polyurethane foam formed from the flexible polyurethane foam-forming composition of claim 1 .
13 . The flexible polyurethane foam of claim 12 , wherein the flexible polyurethane foam has a hardness that is greater than the hardness of a foam formed in the absence of the polyether functional silicone (e).
14 . The flexible polyurethane foam-forming composition of claim 1 comprising water in an amount of about 0.5 parts by weight to about 5 parts by weight based on the weight of the polyurethane foam-forming composition.
15 . The flexible polyurethane foam-forming composition of claim 1 comprising a blowing agent selected from methylene chloride or carbon dioxide.