Sensitizer dyes for photoacid generating systems
View Patent ↗Photosensitizing dyes are often used in conjunction with a photoacid generator in holographic recording media. Conventional photosensitizing dyes typically are limited by having an appreciable absorption of light when used in a sufficient concentration, such that the intensity of light decreases significantly with penetration into a recording medium. The present invention discloses a number of new 5-alkynyl substituted napthacene photosensitizing dyes that have low extinction coefficients coupled with good sensitizing properties, such that the problems associated with the photosensitizing dyes absorbing light are significantly reduced.
1. A dye represented by Structural Formula (I):
wherein:
R 1 is a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or —Si(R 5 ) 3 ;
R 2 , R 3 , and R 4 are each independently —H, a halogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group;
each R 5 is independently a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl group; and rings A and B are independently substituted or unsubstituted.
2. The dye of claim 1 , wherein rings A and B are unsubstituted.
3. The dye of claim 2 wherein the dye is represented by Structural Formula (II):
wherein
R 4 is —H, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.
4. The dye of claim 3 , wherein, R 4 is a substituted or unsubstituted phenyl group.
5. The dye of claim 4 , wherein R 2 and R 3 are —H, and each R 5 is an alkyl group.
6. The dye of claim 5 , wherein each R 5 is a methyl group and R 4 is phenyl.
7. The dye of claim 3 , wherein the dye sensitizes iodonium, sulfonium, diazonium, or phosphonium salts when exposed to actinic radiation and wherein the dye has an extinction coefficient less than 16,000 L mol −1 cm −1 at 532 nm.
8. The dye of claim 1 , wherein R 1 and R 4 are each independently a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl group.
9. The dye of claim 1 , wherein the dye is represented by Structural Formula (III):
wherein R 1 is a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl group.
10. The dye of claim 9 , wherein the dye is represented by Structural Formula (IV):
wherein R 10 is —H, a halogen, or an alkyl, alkoxy, trialkylammonium, or a diarylamino group and y is an integer from 1 to 5.
11. The dye of claim 10 , wherein the dye is represented by Structural Formula (V):
wherein R 2 and R 3 are —H, and R 10 is —H, —CH 3 , or —OCH 3 .
12. A polymerizable medium, wherein said medium comprises:
a) a dye of claim 1 ;
b) a photo acid generator (PAG), which in combination with the dye produces acid when exposed to actinic radiation; and
c) at least one monomer or oligomer which is capable of undergoing cationic polymerization initiated by said acid.
13. The medium of claim 12 , wherein the monomer or oligomer which is capable of undergoing cationic polymerization contains one or more epoxide, oxetane, cyclic ether, 1-alkenyl ether, unsaturated hydrocarbon, lactone, cyclic ester, lactam, cyclic carbonate, cyclic acetal, aldehyde, cyclic sulfide, cyclosiloxane, cyclotriphosphazene, or polyol functional groups, or a combination thereof.
14. The medium of claim 13 , wherein the monomer or oligomer which is capable of undergoing cationic polymerization contains one or more epoxide, oxetane or 1-alkenyl ether functional groups.
15. The medium of claim 14 , wherein said medium comprises a binder or a second monomer or oligomer which is capable of undergoing cationic polymerization.
16. The medium of claim 12 , further including a binder that is capable of supporting cationic polymerization of the monomer or oligomer.
17. The medium of claim 16 , wherein the PAG is a sulfonium, iodonium, diazonium, or phosphonium salt.
18. The medium of claim 17 , wherein the dye is represented by Structural Formula (II):
wherein R 4 is —H, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, R 5 is an alkyl, R 2 and R 3 are —H.
19. The medium of claim 18 , wherein each R 5 is a methyl group and R 4 is phenyl.
20. The medium of claim 17 , wherein R 1 and R 4 are each independently a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group.
21. The medium of claim 20 , wherein R 1 and R 4 are each independently a substituted or unsubstituted aryl group and wherein R 2 and R 3 are —H.
22. The medium of claim 21 , wherein R 1 and R 4 are phenyl.
23. The medium of claim 17 , wherein the dye is represented by Structural Formula (III):
wherein R 1 is a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl group.
24. The medium of claim 23 , wherein the dye is represented by Structural Formula (V):
wherein R 10 is —H, a halogen, or an alkyl, alkoxy, trialkylammonium or diarylamino group.
25. The medium claim 24 , wherein R 2 and R 3 are —H, and R 10 is —H, —CH 3 , or —OCH 3 .
26. The medium of claim 16 , wherein the binder is diffusible and inert to polymerization.
27. The medium of claim 16 , wherein the monomer is an epoxide monomer that comprises one or more cyclohexene oxide groups.
28. The medium of claim 27 , wherein the epoxide monomer is a siloxane comprising two or more cyclohexene oxide groups or a polyfunctional siloxane comprising three or more cyclohexene oxide groups.
29. The medium of claim 16 , wherein the medium comprises a second monomer or oligomer capable of undergoing cationic polymerization.
30. A method of recording holograms within a polymerizable medium of claim 16 comprising the step of passing into the medium a reference beam of coherent actinic radiation and an object beam of the same coherent actinic radiation, wherein the PAG is capable of producing acid upon exposure to said coherent actinic radiation, thereby forming within the medium an interference pattern and thereby recording a hologram within the medium.
31. The method of claim 30 , wherein the binder is diffusible and inert to polymerization.
32. The polymerizable medium of claim 16 , wherein the refractive index of the binder differs from the refractive index of the polymerized monomer by at least 0.04.
33. The polymerizable medium of claim 12 , wherein the dye has an extinction coefficient less than 16,000 L mol −1 cm −1 at 532 nm.
34. A holographic recording medium, wherein said medium comprises:
a) a dye of claim 1 ;
b) a photo acid generating compound (PAG), which in combination with the dye produces acid when exposed to actinic radiation;
c) a monomer or oligomer which is capable of undergoing cationic polymerization initiated by the acid; and
d) a binder that is capable of supporting cationic polymerization of the monomer or oligomer.
35. The holographic recording medium of claim 34 , wherein said medium is greater than 500 μm thick.
36. The holographic recording medium of claim 35 , wherein said medium is greater than 1,000 μm thick.
37. The holographic recording medium of claim 34 , wherein said medium is greater than 300 μm thick.
38. The holographic recording medium of claim 34 , wherein the dye has an extinction coefficient less than 16,000 L mol −1 cm −1 at 532 nm.