Curable compositions, method of coating a phototool, and coated phototool
A curable composition comprises: an epoxy silane represented by formula X—Si(OR 1 )(OR 2 )(OR 3 ) wherein R 1 -R 3 represent C 1 to C 4 alkyl groups, and X represents an organic group having at least one oxirane ring; a fluorinated silane represented by formula; wherein: R f represents a perfluoroalkyl group having from 3 to 5 carbon atoms, R 4 represents H or a C 1 to C 4 alkyl group, and R 5 -R 7 represent C 1 to C 4 alkyl groups; and a photoacid. Use of the curable composition to coat a phototool, thereby providing a protective coating on the phototool is also disclosed.
1. A curable composition comprising:
an epoxy silane represented by formula
X—Si(OR 1 )(OR 2 )(OR 3 )
wherein R 1 , R 2 and R 3 independently represent alkyl groups having from 1 to 4 carbon atoms, and X represents an organic group having at least one oxirane ring;
a fluorinated silane represented by formula
wherein:
R f represents a perfluoroalkyl group having from 3 to 5 carbon atoms;
R 4 represents H or an alkyl group having from 1 to 4 carbon atoms;
R 5 , R 6 and R 7 independently represent alkyl groups having from 1 to 4 carbon atoms; and
Z represents a linear alkylene group; and
a photoacid.
2. The curable composition of claim 1 , wherein the epoxy silane is represented by a formula selected from the group consisting of
wherein R 1 , R 2 and R 3 independently represent alkyl groups having from 1 to 4 carbon atoms, and Q represents a divalent organic linking group that is free of interfering groups.
3. The curable composition of claim 1 , wherein the curable composition contains less than five percent by weight of volatile organic solvent based on a total weight of the curable composition.
4. The curable composition of claim 1 , wherein the R f is perfluorobutyl.
5. The curable composition of claim 4 , wherein the fluorinated silane has the formula CF 3 CF 2 CF 2 CF 2 S(═O) 2 N(CH 3 )CH 2 CH 2 CH 2 Si(OCH 3 ) 3 .
6. The curable composition of claim 1 , wherein the epoxy silane is selected from the group consisting of beta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and gamma-glycidoxypropyltrimethoxysilane.
7. The curable composition of claim 1 , wherein the photoacid is selected from the group consisting of triarylsulfonium salts and diaryliodonium salts.
8. A method of coating a phototool, the method comprising coating a curable composition onto at least a portion of the phototool and curing the curable composition, wherein the curable composition comprises:
an epoxy silane represented by formula
X—Si(OR 1 )(OR 2 )(OR 3 )
wherein R 1 , R 2 and R 3 independently represent alkyl groups having from 1 to 4 carbon atoms, and X represents an organic group having at least one oxirane ring;
a fluorinated silane represented by formula
wherein:
R f represents a perfluoroalkyl group having from 3 to 5 carbon atoms;
R 4 represents H or an alkyl group having from 1 to 4 carbon atoms;
R 5 , R 6 and R 7 independently represent alkyl groups having from 1 to 4 carbon atoms; and
Z represents a linear alkylene group; and
a photoacid.
9. The method of claim 8 , wherein the epoxy silane is represented by a formula selected from the group consisting of
wherein R 1 , R 2 and R 3 independently represent alkyl groups having from 1 to 4 carbon atoms, and Q represents a divalent organic linking group that is free of interfering groups.
10. The method of claim 8 , wherein the curable composition contains less than five percent by weight of volatile organic solvent based on a total weight of the curable composition.
11. The method of claim 8 , wherein the R f is perfluorobutyl.
12. The method of claim 11 , wherein the R 4 is methyl.
13. The method of claim 8 , wherein the epoxy silane is selected from the group consisting of beta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and gamma-glycidoxypropyltrimethoxysilane.
14. The method of claim 8 , wherein the photoacid is selected from the group consisting of triarylsulfonium salts and diaryliodonium salts.
15. A coated phototool comprising a phototool having a protective coating disposed on at least a portion of a major surface thereof; wherein the protective coating comprises a reaction product of a curable composition comprising:
an epoxy silane represented by formula
X—Si(OR 1 )(OR 2 )(OR 3 )
wherein R 1 , R 2 and R 3 independently represent alkyl groups having from 1 to 4 carbon atoms, and X represents an organic group having at least one oxirane ring;
a fluorinated silane represented by formula
wherein:
R f represents a perfluoroalkyl group having from 3 to 5 carbon atoms;
R 4 represents H or an alkyl group having from 1 to 4 carbon atoms;
R 5 , R 6 and R 7 independently represent alkyl groups having from 1 to 4 carbon atoms; and
Z represents a linear alkylene group; and
a photoacid.
16. The coated phototool of claim 15 , wherein the epoxy silane is represented by a formula selected from the group consisting of
wherein R 1 , R 2 and R 3 independently represent alkyl groups having from 1 to 4 carbon atoms, and Q represents a divalent organic linking group that is free of interfering groups.
17. The coated phototool of claim 16 , wherein the curable composition contains less than five percent by weight of volatile organic solvent based on a total weight of the curable composition.
18. The coated phototool of claim 16 , wherein the R f is perfluorobutyl.
19. The coated phototool of claim 18 , wherein the R 4 is methyl.
20. The coated phototool of claim 15 , wherein the epoxy silane is selected from the group consisting of beta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and gamma-glycidoxypropyltrimethoxysilane.
21. The coated phototool of claim 15 , wherein the photoacid is selected from the group consisting of triarylsulfonium salts and diaryliodonium salts.