Water-blown silicone foam

Claim 1

A method of producing an open-cell silicone foam at room temperature consisting of (A) mixing ingredients consisting essentially of (1) 100 parts by weight of a polydiorganosiloxane having organic groups selected from the group consisting of methyl, ethyl, propyl, vinyl, phenyl, and 3,3,3-trifluoropropyl, endblocking consisting of hydroxyl or vinyl groups, and a viscosity of from 0.4 to 100 Pa.sup.. s at 25° C., (2) from 15 to 50 parts by weight of a silicon hydride of the formula ##STR5## where R is an alkyl radical of 1 to 4 carbon atoms or phenyl and R 1 is R or hydrogen, x and y are such that x is from 0 to 40 percent of y, y is at least 3, and x plus y are such that the viscosity of the silicon hydride is below 0.05 Pa.sup.. s at 25° C., (3) from 0.5 to 15 parts by weight of water, (4)from 10 to 100 parts by weight of platinum per million parts of (A) in the form of a platinum catalyst, (5) optionally a profoamer consisting essentially of a resinous, benzene-soluble organosiloxane copolymer consisting essentially of SiO 4/2 units, silicon-bonded hydroxyl groups, (CH 3 ) 3 SiO 1/2 units and fluorine-containing units selected from the group consisting of R a R b 'SiO.sub.(4-a-b)/2 and R"[Si(R') b O.sub.(3-b)/2 ] 2 and mixtures thereof, where R is a monovalent organic radical containing at least four perfluorinated carbon atoms and is bonded to the silicon atom of said fluorine-containing units by a sequence of at least two methylene units or by an oxygen atom that is, in turn, bonded to a sequence of at least two methylene units, R' is an alkyl radical containing from 1 to 3 carbon atoms, and R" is a divalent organic radical containing at least four perfluorinated carbon atoms and is bonded to the silicon atom of said fluorinecontaining units by means of a carbon or oxygen atom, a is 1 or 2, b is 0, 1 or 2 and the sum of a and b is 3 or less with the provision that when R and R" represent fluorine-containing units bonded to silicon via an oxygen atom the organosiloxane copolymer optionally contains repeating units of the formula GSiO 3/2 where G represents the residue obtained by removal of the hydrogen atom from a hydroxyl group of a linear organic polymer containing an average of at least one terminal hydroxyl group per molecule and selected from the group consisting of polyethers, polyoxyalkylene glycols, homopolymers of ethylenically unsaturated alcohols and copolymers of ethylenically unsaturated alcohols with ethylenically unsaturated hydrocarbons; the molar ratio of all units other than hydroxyl and SiO 4/2 units to SiO 4/2 units is from 0.7:1 to 1.1:1, inclusive, and the concentration of said fluorinecontaining units and any GSiO 3/2 units is sufficient to (a) impart a surface tension of less than 2.2×10 -4 newtons per centimeter at 25° C. to a 10 percent by weight solution of (5) in a hydroxyl endblocked polydimethylsiloxane exhibiting a viscosity of 0.08 Pa.s at 25° C., and (b) require the addition of from 0 to 100 percent by weight of xylene to said 10 percent by weight solution to achieve optical clarity, and (6) optionally an alcohol having from 1 to 12 carbon atoms, and (B) allowing the mixture to form a froth and cure at ambient temperature to an elastomeric silicone foam.

Claim 2

A method of producing an open-cell silicone foam at room temperature consisting of (A) mixing ingredients consisting essentially of (1) 100 parts by weight of a polydiorganosiloxane having organic groups selected from the group consisting of methyl, ethyl, propyl, vinyl, phenyl, and 3,3,3-trifluoropropyl, endblocking consisting of hydroxyl or vinyl groups, and a viscosity of from 0.4 to 100 Pa.sup.. s at 25° C., (2) from 15 to 50 parts by weight of a silicon hydride of the formula ##STR5## where R is an alkyl radical of 1 to 4 carbon atoms or phenyl and R 1 is R or hydrogen, x and y are such that x is from 0 to 40 percent of y, y is at least 3, and x plus y are such that the viscosity of the silicon hydride is below 0.05 Pa.sup.. s at 25° C., (3) from 0.5 to 15 parts by weight of water, (4)from 10 to 100 parts by weight of platinum per million parts of (A) in the form of a platinum catalyst, (5) optionally a profoamer consisting essentially of a resinous, benzene-soluble organosiloxane copolymer consisting essentially of SiO 4/2 units, silicon-bonded hydroxyl groups, (CH 3 ) 3 SiO 1/2 units and fluorine-containing units selected from the group consisting of R a R b 'SiO.sub.(4-a-b)/2 and R"[Si(R') b O.sub.(3-b)/2 ] 2 and mixtures thereof, where R is a monovalent organic radical containing at least four perfluorinated carbon atoms and is bonded to the silicon atom of said fluorine-containing units by a sequence of at least two methylene units or by an oxygen atom that is, in turn, bonded to a sequence of at least two methylene units, R' is an alkyl radical containing from 1 to 3 carbon atoms, and R" is a divalent organic radical containing at least four perfluorinated carbon atoms and is bonded to the silicon atom of said fluorinecontaining units by means of a carbon or oxygen atom, a is 1 or 2, b is 0, 1 or 2 and the sum of a and b is 3 or less with the provision that when R and R" represent fluorine-containing units bonded to silicon via an oxygen atom the organosiloxane copolymer optionally contains repeating units of the formula GSiO 3/2 where G represents the residue obtained by removal of the hydrogen atom from a hydroxyl group of a linear organic polymer containing an average of at least one terminal hydroxyl group per molecule and selected from the group consisting of polyethers, polyoxyalkylene glycols, homopolymers of ethylenically unsaturated alcohols and copolymers of ethylenically unsaturated alcohols with ethylenically unsaturated hydrocarbons; the molar ratio of all units other than hydroxyl and SiO 4/2 units to SiO 4/2 units is from 0.7:1 to 1.1:1, inclusive, and the concentration of said fluorinecontaining units and any GSiO 3/2 units is sufficient to (a) impart a surface tension of less than 2.2×10 -4 newtons per centimeter at 25° C. to a 10 percent by weight solution of (5) in a hydroxyl endblocked polydimethylsiloxane exhibiting a viscosity of 0.08 Pa.s at 25° C., and (b) require the addition of from 0 to 100 percent by weight of xylene to said 10 percent by weight solution to achieve optical clarity, and (6) optionally an alcohol having from 1 to 12 carbon atoms, and (B) allowing the mixture to form a froth and cure at ambient temperature to an elastomeric silicone foam.