Silicone release agent

Claim 2

A release composition for molding polyurethanes which comprises a mixture containing an organopolysiloxane fluid having the general formula (R2SiO)n in which R represents an organic radical having from 1 to 18 carbon atoms selected from the group consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals, n is a number greater than 20 and from 0.1 to 90 percent by weight of an aminofunctional silicon compound based on the total weight of the aminofunctional silicon compound and the organopolysiloxane fluid, said aminofunctional silicon compound is obtained from the equilibration of an organopolysiloxane and an aminofunctional silane or siloxane in the presence of a base catalyst.

Claim 3

The composition of claim 1 wherein the organopolysiloxane used in the preparation of the aminofunctional silicon compound is represented by the formula

Claim 4

The composition of claim 1 wherein the organopolysiloxane used in the preparation of the aminofunctional silicon compound is represented by the formula RySiRzO4-y-z in which R is selected from the group consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals, y is a number of from about 0.5 to 2.49, z is a number of from 0.001 to 1 and the sum of y and z is a number of from 1 to 2.5.

Claim 5

The composition of claim 1 wherein the aminofunctional silane, or siloxane is represented by the formula

Claim 6

The composition of claim 1 wherein the aminofunctional silicon compound is present in an amount of from 1.0 to 30 percent by weight based on the total weight of the aminofunctional silicon compound and the organopolysiloxane fluid.

Claim 7

The composition of claim 1 wherein the organopolysiloxane fluid is a polydimethylsiloxane.

Claim 8

The composition of claim 1 wherein the organopolysiloxane fluid and aminofunctional silicon compound is diluted with an organic solvent.

Claim 9

In the process of preparing polyurethane articles which comprises reacting an organic polyisocyanate with an organic Compound having at least two groups bearing Zerewitinoff active hydrogen atoms and allowing the resultant mixture to gel and become tack-free, the improvement of obtaining multiple releases between a mold surface and said polyurethane articles when successively molded therein by the steps of maintaining the ungelled reaction mixture in contact with a solid surface having a release agent thereon until said reaction mixture has gelled and become tack-free, said release agent comprising a mixture of an organopolysiloxane fluid of the general formula: (R2SiO)n in which R represents an organic radical having from 1 to 18 carbon atoms selected from the group consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals, n is a number greater than 20 and from 0.1 to 90 percent by weight of an aminofunctional silicon compound based on the total weight of the aminofunctional silicon compound and the organopolysiloxane fluid, said aminofunctional silicon compound is obtained from the equilibration of an organopolysiloxane and an aminofunctional silane or siloxane in the presence of a base catalyst.

Claim 10

In the process of preparing polyurethane articles which comprises reacting an organic polyisocyanate with an organic Compound having at least two groups bearing Zerewitinoff active hydrogen atoms and allowing the resultant mixture to gel and become tack-free, the improvement of obtaining multiple releases between a mold surface and said polyurethane articles when successively molded therein by the steps of maintaining the ungelled reaction mixture in contact with a solid surface having a release agent thereon until said reaction mixture has gelled and become tack-free, said release agent comprising a mixture of an organopolysiloxane fluid of the general formula: (R2SiO)n in which R represents an organic radical having from 1 to 18 carbon atoms selected from the group consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals, n is a number greater than 20 and from 0.1 to 90 percent by weight of an aminofunctional silicon compound based on the total weight of the aminofunctional silicon compound and the organopolysiloxane fluid, said aminofunctional silicon compound is obtained from the equilibration of an organopolysiloxane and an aminofunctional silane or siloxane in the presence of a base catalyst.

Claim 11

THE PROCESS OF CLAIM 8 WHEREIN A GASEOUS EXPANDING AGENT IS GENERATED IN THE REACTION MIXTURE RESULTING FROM THE REACTION OF SAID ORGANIC POLYISOCYANATE WITH THE ORGANIC COMPOUND BEFORE SAID REACTION MIXTURE HAS GELLED AND BECOME TACK-FREE, WHEREBY THE POLYURETHANE ARTICLES OBTAINED ARE CELLULAR.

Claim 12

The process of claim 8 wherein the release agent is diluted with an organic solvent.