Process for preparing shaped, foamed polyurethane articles

Claim 2

A process for preparing a shaped, foamed polyurethane article comprising shaping a curable froth which is substantially structurally stable but workable at ambient temperatures, said froth comprising a. an organic polyisocyanate; b. an active hydrogen compound reactive with said polyisocyanate to form a polyurethane;

Claim 3

c. a high molecular weight linear non-hydrolyzable (AB) n siloxane-polyoxyalkylene block copolymer having the average formula (Y(R.sub.2 SiO).sub.a R.sub.2 SiYO(C.sub.n H.sub.2n O).sub.y).sub.d wherein R represents a monovalent hydrocarbon radical free from aliphatic unsaturation; n is an integer of from 2 to 4 inclusive; a is an integer of at least 6; y is an integer of at least 4; d is an integer of at least 4; Y represents a divalent organic group selected from the class consisting of --R'--, --R'CO-- --R'--NHCO--, --R'---NCHONH--R"--NHCO-- and --R'--OOCH--R"--NHCO--wherein R' is a divalent alkylene radical and R" is R' or a divalent arylene group; wherein the average molecular weight of each siloxane block ranges from about 500 to about 10,000; wherein the average molecular weight of each polyoxyalkylene block ranges from about 300 to about 10,000; wherein the siloxane blocks constitute about 20 to about 50 weight percent of the copolymer; wherein the polyoxyalkylene blocks constitute about 80 to about 50 weight percent of the copolymer; and wherein the block copolymer has an average weight of at least about 30,000; and d. an inert normally gaseous gas substantially uniformally dispersed throughout said froth; and maintaining the resultant shaped froth at a temperature sufficeint to cure it and set its shape.

Claim 4

c. a high molecular weight linear non-hydrolyzable (AB) n siloxane-polyoxyalkylene block copolymer having the average formula (Y(R.sub.2 SiO).sub.a R.sub.2 SiYO(C.sub.n H.sub.2n O).sub.y).sub.d wherein R represents a monovalent hydrocarbon radical free from aliphatic unsaturation; n is an integer of from 2 to 4 inclusive; a is an integer of at least 6; y is an integer of at least 4; d is an integer of at least 4; Y represents a divalent organic group selected from the class consisting of --R'--, --R'CO-- --R'--NHCO--, --R'---NCHONH--R"--NHCO-- and --R'--OOCH--R"--NHCO--wherein R' is a divalent alkylene radical and R" is R' or a divalent arylene group; wherein the average molecular weight of each siloxane block ranges from about 500 to about 10,000; wherein the average molecular weight of each polyoxyalkylene block ranges from about 300 to about 10,000; wherein the siloxane blocks constitute about 20 to about 50 weight percent of the copolymer; wherein the polyoxyalkylene blocks constitute about 80 to about 50 weight percent of the copolymer; and wherein the block copolymer has an average weight of at least about 30,000; and d. an inert normally gaseous gas substantially uniformally dispersed throughout said froth; and maintaining the resultant shaped froth at a temperature sufficeint to cure it and set its shape.

Claim 5

A process as defined in claim 1, wherein R is a methyl radical; wherein (C n H 2n O) represents a mixture consisting of about 30 to about 75 weight percent of oxyethylene groups and about 70 to about 25 weight percent of oxypropylene groups; wherein Y represents a divalent alkylene group; wherein the average molecular weight of each siloxane block constitutes about 30 to about 45 weight percent of the copolymer and the average molecular weight of the polyoxyalkylene block constitutes about 70 to about 55 weight percent of the copolymer; wherein the average molecular weight of each siloxane block ranges from about 500 to about 5000 and the average molecular weight of each polyoxyalkylene block ranges from about 100 to about 5000; and wherein the block copolymer has an average molecular weight ranging from about 30,000 to about 60,000.

Claim 6

A process as defined in claim 2, wherein Y is a --CH 2 CH 2 CH 2 --radical; wherein the average molecular weight of each siloxane block ranges from about 100 to about 3,500 and wherein the average weight of each polyoxyalkylene block ranges from about 2000 to about 3,500.

Claim 7

A process as defined in claim 3, wherein (C n H 2n O) represents a mixture consisting of about 50 weight percent oxyethylene groups and about 50 weight percent of oxypropylene groups.

Claim 8

A process as defined in claim 2, wherein the polyisocyanate is an aromatic polyisocyanate, wherein the active hydrogen compound is a polyhydroxyl-containing compound and wherein said froth also contains a catalyst having a substantial catalytic activity in the curing of said froth only at temperatures of at least about 70° C.

Claim 9

A process as defined in claim 4, wherein said froth contains as an additional ingredient an inert organic solvent.

Claim 10

A process as defined in claim 5, wherein said polyisocyanate is a tolylene diisocyanate and said active hydrogen compound is a polyether polyol having a hydroxyl number in the range of about 28 to 1000.

Claim 11

A process as defined in claim 5, wherein said active hydrogen compound is an organic polyol blend consisting of a graft copolymer of about 20 percent weight acrylonitrile and about 80 weight percent of a glycerol started propylene oxide adduct triol having a molecular weight of about 3,000 and a hydroxyl number of about 56, the graft copolymer having a hydroxyl number of about 45; a glycerol started propylene oxide adduct triol having a molecular weight of about 700 and a hydroxyl number of about 240; a poly-ε-caprolactone diol having a molecular weight of about 530 and a hydroxyl number of about 212; and said polyisocyanate is a mixture consisting of about 80 weight percent of 2,4 tolylene diisocyanate and about 20 weight percent of 2,6 tolylene diisocyanate.

Claim 12

A process as defined in claim 5, wherein the catalyst is nickel acetylacetonate.

Claim 13

A process as defined in claim 5, wherein the inert gas is air.

Claim 14

A process as defined in claim 5, wherein said froth is substantially non-aqueous and free of auxilliary blowing agents, wherein said polyhydroxyl-containing compound. is substantially reactive with said polyisocyanate only at a temperature of at least 70° C to form a polyurethane, wherein the inert gas is substantially uniformly dispersed throughout the froth by mechanical beating, wherein said polyisocyanate, polyhydroxyl-containing compound, non-hydrolyzable (AB) n block copolymer and catalyst ingredients present in the froth are such that an unfrothed admixture containing only said polyisocyanate, polyhydroxyl-containing compound, non-hydrolyzable (AB) n block copolymer and catalyst ingredients in the same proportions that said ingredients are represented in said froth is chemically stable to the extent that the admixture retains a viscosity of not greater than 10,000 cps. for about 2600 seconds at 25° C ± 0.5° C., wherein said froth has a density of not greater than 45% of the density of the unfrothed liquid phase, and wherein said froth is heated to a temperature of at least 70° C. to form a cured polyurethane foam; any further expansion of said froth during heat curing being substantially only thermal expansion of said inert gas employed.

Claim 15

A process as defined in claim 11, wherein said inert gas is air.

Claim 16

A process as defined in claim 11, where said catalyst is nickel acetylaceonate.

Claim 17

A process as defined in claim 11, wherein said polyisocyanate is an aromatic polyisocyanate or mixtures thereof selected from the group consisting of tolylene diisocyanate, bis(4-isocyanatophenyl) methane, polyphenylmethylene polyisocyanate, a prepolymer of tolylene diisocyanate and any one of the polyhydroxyl compounds defined herein and wherein said polyhydroxyl compound is selected from the group consisting of a polyether polyol, a polymer/polyol of an ethylenically unsaturated monomer and a polyether polyol, a cyclic ester polymer and mixtures thereof, wherein said catalyst is nickel acetylacetonate, wherein said inert gas is air and the mechanical beating is conducted at a pressure of not greater than 100 psig., and wherein said froth has a density of not greater than 35% of the density of the unfrothed liquid phase.

Claim 18

A process as defined in claim 14, wherein a filler and an inert organic solvent are also present in the froth.