UV curable expoxy functional silicones

Claim 2

A UV radiation curable composition comprising: (A) an epoxy functional organopolysiloxane comprising in sufficient number to crosslink and cure said composition units of the formula: R a R 1 b SiO (4-a-b)/2 wherein R is hydrogen, C (1-8) alkyl, or aryl, R¹ is a monovalent epoxy functional organic radical of from 2 to 20 carbon atoms, a is 0, 1, or 2; b is 1, 2 or 3, and a + b is 1, 2 or 3, and in sufficient number to increase capacity to solubilize component (B) modified units of the formula: R c R 2 d SiO (4-c-d)/2 wherein R is given above, R² is the epoxy esterification reaction product of R¹ with HOOC-R³, R³ is hydrogen or a C₁₋₂₀ substituted or unsubstituted hydrocarbon radicals, C is 0, 1 or 2, d is 1, 2 or 3, and c + d is 1, 2 or 3; and (B) a catalytic amount of onium salt photocatalyst.

Claim 3

The composition of Claim 1 wherein said epoxy functional organopolysiloxane is substantially linear.

Claim 4

The composition of Claim 1 wherein b and d are 1.

Claim 5

The composition of Claim 1 wherein from about 1 to about 20% by number silicone units are epoxy functional silicone units and from about 1 to about 20% by number silicone units are modified epoxy functional silicone units.

Claim 6

The composition of Claim 1 wherein said epoxy functional organopolysiloxane has a viscosity from 10 to 500,000 centipoise at 25°C.

Claim 7

The composition of Claim 1 wherein HOOC -R³ is selected from the group consisting of aromatic acids, alkylene acids and alkyl acids.

Claim 8

The composition of Claim 1 wherein HOOC-R³ is selected from benzoic acid.

Claim 9

The composition of Claim 1 wherein said onium salt photocatalyst is selected from halonium salts, sulfonium salts, and phosphonium salts.

Claim 10

The composition of Claim 1 wherein there is from about 0.1% to about 15% by weight of onium photocatalyst based on total composition.

Claim 11

The composition of Claim 1 wherein there is additionally employed an effective amount of dye sensitizer.

Claim 12

The composition of claim 10 wherein there is employed from about 0.01 to about 1.5% by weight dye sensitizer based on total composition.

Claim 13

The composition of Claim 10 wherein said dye sensitizer is a thioxanthone or aminoxanthone.

Claim 14

The composition of Claim 1 wherein there is additionally employed an epoxy functional organic compound in an effective amount to further crosslink.

Claim 15

The composition of Claim 13 wherein there is employed from about 1 to about 50% by weight epoxy functional organic compound based on epoxy functional organopolysiloxane.

Claim 16

A UV radiation curable composition consisting essentially of: (A) an epoxy functional organopolysiloxane comprising in sufficient number to crosslink and cure said composition units of the formula: R a R 1 b SiO (4-a-b-)/2 wherein R is hydrogen, C (1-8) alkyl, or aryl, R¹ is a monovalent epoxy functional organic radical of from 2 to 20 carbon atoms, a is 0, 1 or 2 carbon atoms, a is 0, 1 or 2, b is 1, 2 or 3, and a + b is 1, 2 or 3, and in sufficient number to increase capacity to solubilize component (B) modified units of the formula: R c R 2 d SiO (4-c-d)/2 wherein R is given above, R² is the epoxy esterification reaction product of R¹ with HOOC-R³m R³ is hydrogen or a C₁₋₂₀ substituted or unsubstituted hydrocarbon radical, c is 0, 1 or 2, d is 1, 2 or 3 and c + d is 1, 2 or 3; and (B) a catalytic amount of onium salt photocatalyst, (C) an effective amount of dye sensitizer, and (D) an epoxy functional organic compound in an effective amount to further crosslink.

Claim 17

A UV radiation curable composition consisting essentially of: (A) an epoxy functional organopolysiloxane comprising in sufficient number to crosslink and cure said composition units of the formula: R a R 1 b SiO (4-a-b-)/2 wherein R is hydrogen, C (1-8) alkyl, or aryl, R¹ is a monovalent epoxy functional organic radical of from 2 to 20 carbon atoms, a is 0, 1 or 2 carbon atoms, a is 0, 1 or 2, b is 1, 2 or 3, and a + b is 1, 2 or 3, and in sufficient number to increase capacity to solubilize component (B) modified units of the formula: R c R 2 d SiO (4-c-d)/2 wherein R is given above, R² is the epoxy esterification reaction product of R¹ with HOOC-R³m R³ is hydrogen or a C₁₋₂₀ substituted or unsubstituted hydrocarbon radical, c is 0, 1 or 2, d is 1, 2 or 3 and c + d is 1, 2 or 3; and (B) a catalytic amount of onium salt photocatalyst, (C) an effective amount of dye sensitizer, and (D) an epoxy functional organic compound in an effective amount to further crosslink.