Silicone release coatings and inhibitors

Claim 2

A silicone release coating composition having improved catalyzed bath life at ambient temperatures comprised of: a. an olefinorganopolysiloxane having units of the structural formula ##EQU6## b. an organohydrogenpolysiloxane having units of the structural formula ##EQU7## wherein R is selected from the group consisting of a monovalent hydrocarbon radical, a halogenated monovalent hydrocarbon radical, a cyanoalkyl radical and mixtures thereof, R' is an olefinic hydrocarbon radical, wherein a has a value of from 0 to 3, inclusive, b has a value of from 0.005 to 2.0, inclusive, and the sum of a and b is equal to from 0.8 to 3, inclusive; c. a sufficient amount of a precious metal catalyst to cause the co-reaction of (a) and (b); and d. a dialkylacetylenedicarboxylate having the general formula ROOCC.tbd.CCOOR where R is as defined above and wherein said dialkylacetylenedicarboxylate is present in an amount effective for inhibiting premature gelation but insufficient for preventing cure at elevated temperature; wherein said silicone release coating composition has a viscosity of, approximately, 25 to 5000 centipoise at 25° C.

Claim 3

A composition as in claim 1 wherein said olefinorganopolysiloxane is a dimethylvinyl chainstopped dimethylmethylvinylpolysiloxane copolymer fluid having a viscosity of, approximately, 300 to 1000 centipoise at 25° C. and a vinyl content of, approximately, 0.1 to 2.5 weight percent.

Claim 4

A composition as in claim 1 wherein said organohydrogenpolysiloxane is a trimethyl chainstopped methylhydrogenpolysiloxane fluid having a viscosity of, approximately, 10 to 500 centipoise at 25° C. at a hydrogen content of, approximately 0.1 to 1.67 weight percent.

Claim 5

A composition as in claim 1 wherein said precious metal catalyst is selected from the group consisting of platinum metal, rhodium metal and complexes of platinum metal and rhodium metal.

Claim 6

A composition as in claim 4 wherein said precious metal catalyst is present in an amount sufficient to provide, approximately, 5 to 500 parts platinum or rhodium metal per million parts of said olefinorganopolysiloxane.

Claim 7

A composition as in claim 1 wherein said dialkylacetylenedicarboxylate is present in an amount of, approximately, 0.02 to 1.0 weight percent of the silicone coating composition.

Claim 8

A composition as in claim 1 wherein said dialkylacetylenedicarboxylate is selected from the group consisting of dimethylacetylenedicarboxylate, diethylacetylenedicarboxylate, and methylethylacetylenedicarboxylate, dibutylacetylenedicarboxylate, and methylbutylacetylenedicarboxylate.

Claim 9

A composition as in claim 1 further comprising a substrate upon which said silicone coating composition has been coated and thermally cured.

Claim 10

A composition as in claim 8 wherein said substrate is paper.

Claim 11

A process for rendering surfaces nonadherent to materials which would normally adhere thereto comprising the steps of: A. providing a silicone release coating composition by combining: a. an olefinorganopolysiloxane having units of the structural formula: ##EQU8## b. an organohydrogenpolysiloxane having units of the structural formula: ##EQU9## wherein R is selected from the group consisting of a monovalent hydrogen radical, a halogenated monovalent hydrocarbon radical, a cyanoalkyl radial and mixtures thereof, R' is an olefinic hydrocarbon radical, wherein a has a value of from 0 to 3, inclusive, b has a value of from 0.005 to 2.0, inclusive, and the sum of a and b is equal to from 0.8 to 3, inclusive; c. a sufficient amount of a precious metal catalyst to cause the co-reaction of (a) and (b); and d. a dialkylacetylenedicarboxylate having the general formula: ROOCC.tbd.CCOOR where R is as defined above and wherein said dialkylacetylenedicarboxylate is present in an amount effective for inhibiting premature gelation but insufficient for preventing cure at elevated temperature; wherein said silicone release coating has a viscosity of, approximately, 25 to 5000 centipoise at 25° C.; B. Coating said silicone release coating on a suitable surface at a thickness of, approximately, 0.05 to 2.0 mils; C. Curing said silicone release coating with an amount of heat effective for overcoming the cure retarding properties of said dialkylacetylenedicarboxylate.

Claim 12

A process for rendering surfaces nonadherent to materials which would normally adhere thereto comprising the steps of: A. providing a silicone release coating composition by combining: a. an olefinorganopolysiloxane having units of the structural formula: ##EQU8## b. an organohydrogenpolysiloxane having units of the structural formula: ##EQU9## wherein R is selected from the group consisting of a monovalent hydrogen radical, a halogenated monovalent hydrocarbon radical, a cyanoalkyl radial and mixtures thereof, R' is an olefinic hydrocarbon radical, wherein a has a value of from 0 to 3, inclusive, b has a value of from 0.005 to 2.0, inclusive, and the sum of a and b is equal to from 0.8 to 3, inclusive; c. a sufficient amount of a precious metal catalyst to cause the co-reaction of (a) and (b); and d. a dialkylacetylenedicarboxylate having the general formula: ROOCC.tbd.CCOOR where R is as defined above and wherein said dialkylacetylenedicarboxylate is present in an amount effective for inhibiting premature gelation but insufficient for preventing cure at elevated temperature; wherein said silicone release coating has a viscosity of, approximately, 25 to 5000 centipoise at 25° C.; B. Coating said silicone release coating on a suitable surface at a thickness of, approximately, 0.05 to 2.0 mils; C. Curing said silicone release coating with an amount of heat effective for overcoming the cure retarding properties of said dialkylacetylenedicarboxylate.

Claim 13

A process as in claim 10 wherein said olefinorganopolysiloxane is a dimethylvinyl chainstopped dimethylmethylvinylpolysiloxane copolymer fluid having a viscosity of, approximately, 300 to 1000 centipoise at 25° C. and a vinyl content of, approximately, 0.1 to 25 weight percent.

Claim 14

A process as in claim 10 wherein said organohydrogenpolysiloxane is a trimethyl chainstopped methylhydrogenpolysiloxane fluid having a viscosity of, approximately, 10 to 500 centipoise at 25° C. and a hydrogen content of, approximately 0.1 to 1.67 weight pecent.

Claim 15

A process as in claim 10 wherein said precious metal catalyst is selected from the group consisting of platinum metal, rhodium metal and complexes of platinum metal and rhodium metal.

Claim 16

A process as in claim 13 wherein said precious metal catalyst is present in an amount sufficient to provide, approximately, 5 to 500 parts platinum or rhodium metal per million parts of said olefinorganopolysiloxane.

Claim 17

A process as in claim 10 wherein said dialkylacetylenedicarboxylate is present in an amount of, approximately, 0.02 to 1.0 weight percent of the silicone coating composition.

Claim 18

A process as in claim 10 wherein said dialkylacetylenedicarboxylate is selected from the group consisting of dimethylacetylenedicarboxylate and diethylacetylenedicarboxylate.

Claim 19

A process as in claim 10 wherein the group of radicals represented by R also contains hydroxyl radicals.

Claim 20

A composition as in claim 1 wherein said olefinorganopolysiloxane is a dimethylvinyl chainstopped dimethylmethylvinylpolysiloxane copolymer fluid having a viscosity of, approximately, 1,000 to 100,000 centipoise at 25° C.

Claim 21

A process as in claim 10 wherein said olefinorganopolysiloxane is a dimethylvinyl chainstopped dimethylmethylvinylpolysiloxane copolymer fluid having a viscosity of, approximately, 1,000 to 100,000 centipoise at 25° C.