Visible radiation activated hydrosilation reaction

Claim 2

A hydrosilation process which comprises reacting a composition comprising a compound having aliphatic unsaturation and a compound containing at least one silicon-bonded hydrogen atom and not having more than three hydrogen atoms attached to any one silicon atom, in the presence of both a (η 5 -cyclopentadienyl)tri(σ-aliphatic)platinum complex and a sensitizer that is capable of absorbing visible light and that is capable of transferring energy to said platinum complex such that the hydrosilation reaction is initiated upon exposure to visible light.

Claim 3

The process of claim 1 wherein said reaction is carried out by means of exposing said composition to visible radiation.

Claim 4

The process of claim 1 wherein said sensitizer has a triplet energy of at least 31 Kcal/mole.

Claim 5

The process of claim 1 wherein said sensitizer is a polycyclic aromatic compound.

Claim 6

The process of claim 4 wherein said polycyclic aromatic compound has from two to five rings, inclusive.

Claim 7

The process of claim 5 wherein said polycyclic aromatic compound is selected from the group consisting of 9,10-dimethylanthracene, 9,10-dichloroanthracene, 2-ethyl-9,10-dimethylanthracene, and azulene.

Claim 8

The process of claim 1 wherein said sensitizer is an aromatic compound containing a ketone chromophore.

Claim 9

The process of claim 7 wherein said aromatic compound is a thioxanthone.

Claim 10

The process of claim 8 wherein said thioxanthone is selected from the group consisting of thioxanthone, 2-chlorothioxanthone, and 2-isopropylthioxanthone.

Claim 11

The process of claim 1 wherein the platinum complex has the formula ##STR12## wherein Cp represents a cyclopentadienyl group that is eta-bonded to the platinum atom, the cyclopentadienyl group being unsubstituted or substituted by one or more groups that do not interfere in a hydrosilation reaction, and each of R 1 , R 2 , and R 3 represents an aliphatic group having from one to eighteen carbon atoms, said R 1 , R 2 , and R 3 groups being sigma-bonded to the platinum atom.

Claim 12

The process of claim 10 wherein the platinum complex is selected from the group consisting of: (η 5 -cyclopentadienyl)trimethylplatinum, (η 5 -methylcyclopentadienyl)trimethylplatinum, (η 5 -trimethylsilylcyclopentadienyl)trimethylplatinum, and (η 5 -dimethylphenylsilylcyclopentadienyl)trimethylplatinum.

Claim 13

The process of claim 1 wherein the composition comprises from about 0.1 to about 10.0 equivalent weights of the compound having silicon-bonded hydrogen per equivalent weight of the compound having aliphatic unsaturation, and, per 1,000,000 parts by weight of the total composition, from about 5 to about 1000 parts by weight of the platinum catalyst, and from about 50 to about 50,000 parts by weight of the sensitizer.

Claim 14

The process of claim 1 wherein the compound containing aliphatic unsaturation is a polyorganosiloxane having the general formula: ##STR13## wherein each R 6 independently represents a member selected from the group consisting of non-halogenated or halogenated ethylenically-unsaturated groups, non-halogenated or halogenated alkyl groups, non-halogenated or halogenated cycloalkyl groups, and the phenyl group, provided that at least 70% of all R 6 groups are methyl groups, but no more than 10% of all R 6 groups are vinyl groups or other alkenyl groups, further provided that at least two of the R 6 groups are vinyl groups or other alkenyl groups, h is a number having a value from 1 to about 3000, and g is 0, 1, 2, or 3.

Claim 15

The process of claim 1 wherein the compound containing silicon-bonded hydrogen is a polyorganohydrosiloxane having the general formula: ##STR14## wherein each R 8 independently represents a member selected from the group consisting of alkyl groups, cycloalkyl groups, phenyl group, and hydrogen, provided that at least two but no more than one-half of all the R 8 groups in the siloxane are hydrogen, m is 0, 1, 2 or 3, and n is a number having an average value from one to about 3000.

Claim 16

The process of claim 1 wherein the compound having aliphatic unsaturation is one having olefinic unsaturation.

Claim 17

A radiation-curable composition comprising: (a) a silicon compound containing at least one hydrogen atom attached to silicon per molecule, there being not more than three hydrogen atoms attached to any one silicon atom, (b) a compound containing aliphatic unsaturation, (c) a (η 5 -cyclopentadienyl)tri(σ-aliphatic)platinum complex, and (d) a sensitizer that is capable of absorbing visible light and that is capable of transferring energy to said platinum complex when said composition is exposed to visible light.

Claim 18

A radiation-curable composition comprising: (a) a silicon compound containing at least one hydrogen atom attached to silicon per molecule, there being not more than three hydrogen atoms attached to any one silicon atom, (b) a compound containing aliphatic unsaturation, (c) a (η 5 -cyclopentadienyl)tri(σ-aliphatic)platinum complex, and (d) a sensitizer that is capable of absorbing visible light and that is capable of transferring energy to said platinum complex when said composition is exposed to visible light.

Claim 19

The composition of claim 16 wherein said sensitizer has a triplet energy of at least 31 Kcal/mole.

Claim 20

The composition of claim 16 wherein said sensitizer is a polycyclic aromatic compound.

Claim 21

The composition of claim 18 wherein said polycyclic aromatic compound has from two to five rings, inclusive.

Claim 22

The composition of claim 19 wherein said polycyclic aromatic compound is selected from the group consisting of 9,10-dimethylanthracene, 9,10-dichloroanthracene, 2-ethyl-9,10-dimethylanthracene, and azulene.

Claim 23

The composition of claim 16 wherein said sensitizer is an aromatic compound containing a ketone chromophore.

Claim 24

The composition of claim 21 wherein said aromatic compound is a thioxanthone.

Claim 25

The composition of claim 22 wherein said thioxanthone is selected from the group consisting of thioxanthone, 2-chlorothioxanthone, and 2-isopropylthioxanthone.

Claim 26

The composition of claim 16 wherein the platinum complex is represented by the formula: ##STR15## wherein Cp represents a cyclopentadienyl group that is eta-bonded to the platinum atom, the cyclopentadienyl group being unsubstituted or substituted by one or more groups that do not interfere in a hydrosilation reaction, and each of R 1 , R 2 , and R 3 represents an aliphatic group having from one to eighteen carbon atoms, said R 1 , R 2 , and R 3 groups being sigma-bonded to the platinum atom.

Claim 27

The composition of claim 24 wherein the platinum complex is selected from the group consisting of: (η 5 -cyclopentadienyl)trimethylplatinum, (η 5 -methylcyclopentadienyl)trimethylplatinum, (η 5 -trimethylsilylcyclopentadienyl)trimethylplatinum, and (η 5 -dimethylphenylsilycyclopentadienyl)trimethylplatinum.

Claim 28

The composition of claim 16, said composition comprising from about 0.1 to about 10.0 equivalent weights of the compound having silicon-bonded hydrogen per equivalent weight of the compound having aliphatic unsaturation, and per 1,000,000 parts by weight of the total composition, from about 5 to about 1000 parts by weight of the platinum complex and from about 50 to about 50,000 parts by weight of the sensitizer.

Claim 29

Radiation-curable composition comprising (a) a polyorganohydrosiloxane having the general formula: ##STR16## wherein each R 8 independently represents a member selected from the group consisting of alkyl groups, cycloalkyl groups, phenyl group, and hydrogen, provided that at least two but no more than one-half of all the R 8 groups in the siloxane are hydrogen; m is 0, 1, 2 or 3, and n is a number having an average value from one to about 3000, (b) a polyorganosiloxane having the general formula: ##STR17## wherein each R 6 independently represents a member selected from the group consisting of non-halogenated or halogenated ethylenically unsaturated groups, non-halogenated or halogenated alkyl groups, non-halogenated or halogenated cycloalkyl groups, and the phenyl group, provided that at least 70% of all R 6 groups are methyl groups, but no more than 10% of all R 6 groups are vinyl groups or other alkenyl groups, further provided that at least two of the R 6 groups are vinyl groups or other alkenyl groups, h is a number having a value from 1 to about 3000, and g is 0, 1, 2, or 3, (c) a platinum complex represented by the formula: ##STR18## wherein Cp represents a cyclopentadienyl group that is eta-bonded to the platinum atom, the cyclopentadienyl group being unsubstituted or substituted by one of more groups that are inert in a hydrosilation reaction, and each of R 1 , R 2 , and R 3 represents an aliphatic group having from one to eighteen carbon atoms, said R 1 , R 2 , and R 3 groups being sigma-bonded to the platinum atom, and (d) a sensitizer that is capable of absorbing visible light and that is capable of transferring energy to said platinum complex when said composition is exposed to visible light.

Claim 30

Radiation-curable composition comprising (a) a polyorganohydrosiloxane having the general formula: ##STR16## wherein each R 8 independently represents a member selected from the group consisting of alkyl groups, cycloalkyl groups, phenyl group, and hydrogen, provided that at least two but no more than one-half of all the R 8 groups in the siloxane are hydrogen; m is 0, 1, 2 or 3, and n is a number having an average value from one to about 3000, (b) a polyorganosiloxane having the general formula: ##STR17## wherein each R 6 independently represents a member selected from the group consisting of non-halogenated or halogenated ethylenically unsaturated groups, non-halogenated or halogenated alkyl groups, non-halogenated or halogenated cycloalkyl groups, and the phenyl group, provided that at least 70% of all R 6 groups are methyl groups, but no more than 10% of all R 6 groups are vinyl groups or other alkenyl groups, further provided that at least two of the R 6 groups are vinyl groups or other alkenyl groups, h is a number having a value from 1 to about 3000, and g is 0, 1, 2, or 3, (c) a platinum complex represented by the formula: ##STR18## wherein Cp represents a cyclopentadienyl group that is eta-bonded to the platinum atom, the cyclopentadienyl group being unsubstituted or substituted by one of more groups that are inert in a hydrosilation reaction, and each of R 1 , R 2 , and R 3 represents an aliphatic group having from one to eighteen carbon atoms, said R 1 , R 2 , and R 3 groups being sigma-bonded to the platinum atom, and (d) a sensitizer that is capable of absorbing visible light and that is capable of transferring energy to said platinum complex when said composition is exposed to visible light.