Polyether silicone surfactants for the manufacture of urethane foams
AssigneeDow Corning Corporation
InventorsMichael A. Stanga, John H. Frey, Robert F. Hoffman, Robert E. Stevens
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Abstract
Silicone surfactants having a siloxane backbone and polyether pendants having average atomic masses of 2250. The surfactants of the invention operate in polyurethane foam compositions to provide stable foams over a range of surfactant concentrations while still producing product foams without splits. Also disclosed and claimed are polyurethane foam compositions which include the surfactants, a method of making polyurethane foam using the surfactants, and polyurethane foam made by the method.
Claims10
A composition of matter having the average formula MD.sub.90.5 D'.sub.6.5 M
- wherein
- M represents (CH.sub.3).sub.3 SiO.sub.1/2 or R(CH.sub.3).sub.2 SiO.sub.1/2 ;
- D represents (CH.sub.3).sub.2 SiO.sub.2/2 ;
- D' represents (CH.sub.3)(R)SiO.sub.2/2 ;
- wherein in the above formula for M and D', and R is a polyether-containing substituent derived from a C.sub.n H.sub.2n -initiated polyether having --C.sub.n H.sub.2n O(C.sub.2 H.sub.4 O).sub.a (C.sub.3 H.sub.6 O).sub.b R" moieties having average atomic masses in the range 1500-3000 and wherein
- n is 3-4;
- a is a number such that ethylene oxide residues constitute 30-55% by weight of the polyether;
- b is a number such that propylene oxide residues constitute 45-70% by weight of the polyether;
- and
- R" represents H, an alkyl group of 1-4 carbon atoms, or --C(O)CH.sub.3.
In a polyurethane foam composition comprising:
- a polyol, an organic polyisocyanate, at least one urethane catalyst, a blowing agent, a siloxane-oxyalkylene copolymer cell stabilizer, the improvement which comprises:
- a siloxane-oxyalkylene copolymer having the generalized average formula
- MD.sub.90.5 D'.sub.6.5 M
- wherein
- M represents (CH.sub.3).sub.3 SiO.sub.1/2 or R(CH.sub.3).sub.2 SiO.sub.1/2 ;
- D represents (CH.sub.3).sub.2 SiO.sub.2/2 ;
- D' represents (CH.sub.3)(R)SiO.sub.2/2 ;
- wherein in the above formula for M and D', R is a polyether-containing substituent derived from a C.sub.n H.sub.2n -initiated polyether having --C.sub.n H.sub.2n O(C.sub.2 H.sub.4 O).sub.a (C.sub.3 H.sub.6 O).sub.b R" moieties having average atomic masses in the range 1500-3000 and wherein
- n is 3-4;
- a is a number such that ethylene oxide residues constitute 30-55% by weight of the polyether;
- b is a number such that propylene oxide residues constitute 45-70% by weight of the polyether;
- and
- R" represents H, an alkyl group of 1-4 carbon atoms, or --C(O)CH.sub.3.
In a method of preparing polyurethane foam, which comprises reacting a polyol and an organic polyisocyanate in the presence of at least one urethane catalyst, a blowing agent and a siloxaneoxyalkylene copolymer cell stabilizer, the improvement which comprises:
- employing as the cell stabilizer a siloxaneoxyalkylene copolymer having the generalized average formula
- MD.sub.90.5 D'.sub.6.5 M
- wherein
- M represents (CH.sub.3).sub.3 SiO.sub.1/2 or R(CH.sub.3).sub.2 SiO.sub.1/2 ;
- D represents (CH.sub.3).sub.2 SiO.sub.2/2 ;
- D' represents (CH.sub.3)(R)SiO.sub.2/2 ;
- wherein the above formula for M and D, R is a polyether-containing substituent derived from a C.sub.n H.sub.2n -initiated polyether having moieties having average atomic masses in the range 1500-3000 and wherein
- n is 3-4;
- a is a number such that ethylene oxide residues constitute 30-55% by weight of the polyether;
- b is a number such that propylene oxide residues constitute 45-70% by weight of the polyether;
- and
- R" represents H, an alkyl group of 1-4 carbon atoms, or --C(O)CH.sub.3.
Dependencies are inferred from the claim text.