Photosensitive composition containing a transition metal coordination complex cation and a borate anion and photosensitive materials employing the same

• US 4,954,414 A
• Filed: 11/08/1988
• Issued: 09/04/1990
• Est. Priority Date: 11/08/1988
• Status: Expired due to Term

• Current Assignee: Eastman Kodak Company
• Original Assignee: MEAD Corporation (Meadwestvaco Corporation)
• Inventors: Adair, Paul C., Gottschalk, Peter
• Primary Examiner(s): McCamish, Marion C.
• Assistant Examiner(s): Hamilton, Cynthia
• Application Number:
  US07/268,433
• Time in Patent Office: 665 Days
• Field of Search: 544/229, 544/225, 540/3, 540/4, 546/2, 546/8, 546/13, 549/3, 549/4, 556/7, 522/66, 522/26, 522/28, 522/29, 522/63, 522/64, 430/138, 430/281, 430/914, 430/936, 430/917
• US Class Current: 430/138
• CPC Class Codes: G03F 7/029 Inorganic compounds; Onium compounds; Organic compounds having hetero atoms other than oxygen, nitrogen or sulfur
• CPC Class Codes: Y10S 430/115 Cationic or anionic
• CPC Class Codes: Y10S 430/118 with inhibitor or stabilizer
• CPC Class Codes: Y10S 430/137 Cobalt complex containing

Abstract

A composition including a cationic transition metal coordination complex and a borate anion, wherein said composition is capable of absorbing actinic radiation and producing free radicals which can initiate free radical addition polymerization of a free radical addition polymerizable or crosslinkable monomer is disclosed. The compositions are particularly useful as visible light photoinitiators.

Claims

1. A photoinitiator including a cationic transition metal coordination complex and a borate anion wherein said borate anion is represented by the following formula:

##STR3## wherein R₁, R₂, R₃ and R₄ are the same or different and are selected from the group consisting of alkyl, aryl, aralkyl, alkaryl, alkenyl, alkynyl, alicyclic, heterocyclic, and allyl groups, and wherein said photoinitiator is capable of absorbing actinic radiation and producing free radicals.

2. The photoinitiator according to claim 1 wherein three of said R₁, R₂, R₃ and R₄ groups are aryl and one of said R₁, R₂, R₃ and R₄ groups is alkyl.

3. The photoinitiator according to claim 2 wherein said cationic transition metal coordination complex is a complex of a transition metal atom having a d⁶ orbital configuration and one or more ligands covalently bonded to said transition metal atom so that said complex is capable of underdoing metal to ligand charge transfer upon photoexcitation.

4. The photoinitiator according to claim 3 wherein said cationic transition metal coordination complex includes a transition metal selected from the group consisting of Re(I), Fe(II), Ru(II), Os(II), Co(III) and Ir(III).

5. The photoinitiator according to claim 4 wherein said cationic transition metal coordination complex and said borate anion are present as an ion pair.

6. The photoinitiator according to claim 5 wherein at least one of said ligands includes a heterocyclic group containing a nitrogen atom.

7. The photoinitiator according to claim 6 wherein at least one of said ligands is selected from the group consisting of pyridine, 2,2'"'"'-bipyridine, 4,4'"'"'-dimethyl-2,2'"'"'-bipyridine, 1,10-phenanthroline, 3,4,7,8-tetramethyl-1,10-phenanthroline, 2,2'"'"',2"-terpyridine, 5,6-dimethyl-1,10-phenanthroline, 5-methyl-1,10-phenanthroline, 5-chloro-1,10-phenanthroline, 5-nitro-1,10-phenanthroline, 4,7-dimethyl-1,10-phenanthroline and 2,4,6-tri(2-pyridyl-s-triazine and substituted derivatives thereof.

8. The photoinitiator according to claim 5 wherein one or more of said ligands is a bidentate or tridentate ligand.

9. The photoinitiator according to claim 1 wherein said photoinitiator is capable of absorbing actinic radiation and producing free radicals as a result of exposure to light emitted from a visible or near ultraviolet light source.

10. A photoresist material comprising a free radical addition polymerizable or crosslinkable compound and a photoinitiator including a cationic transition metal coordination complex and a borate anion wherein said borate anion is represented by the following formula:

##STR4## wherein R₁, R₂, R₃ and R₄ are the same or different and are selected from the group consisting of alkyl, aryl, aralkyl, alkaryl, alkenyl, alkynyl, alicyclic, heterocyclic, and allyl groups, and wherein said photoinitiator is capable of absorbing actinic radiation and producing free radicals which can initiate free radical polymerization of said polymerizable or crosslinkable compound.

11. The material composition according to claim 10 wherein three of said R₁, R₂, R₃ and R₄ groups are aryl and one of said R₁, R₂, R₃ and R₄ groups is alkyl.

12. The material according to claim 10 wherein said cationic transition metal coordination complex is a complex of a transition metal atom having a d⁶ orbital configuration and one or more ligands covalently bonded to said transition metal atom so that said complex is capable of undergoing metal to ligand charge transfer upon photoexcitation..

13. The material according to claim 12 wherein said cationic transition metal coordination complex includes a transition metal atom selected from the group consisting of Re(I), Fe(II), Ru(II), Os(II), Co(III) and Ir(III).

14. The material according to claim 13 wherein said cationic transition metal coordination complex and said borate anion are present as an ion pair.

15. The material according to claim 14 wherein at least one of said ligands includes a hetercyclic group containing a nitrogen atom.

16. The material according to claim 15 wherein at least one of said ligands is selected from the group consisting of pyridine, 2,2'"'"'-bipyridine, 4,4'"'"'-dimethyl-2,2'"'"'-bipyridine, 1,10-phenanthroline, 3,4,7,8-tetramethyl-1,10-phenanthroline, 2,2'"'"',2"-terpyridine, 5,6-dimethyl-1,10-phenanthroline, 5-methyl-1,10-phenanthroline, 5-chloro-1,10-phenanthroline, 5-nitro-1,10-phenanthroline, 4,7-dimethyl-1,10-phenanthroline and 2,4,6-tri(2-pyridyl-s-triazine) and substituted derivatives thereof.

17. The material according to claim 14 wherein at least one of said ligands is a bidentate or tridentate ligand.

18. The material according to claim 10 wherein said photoinitiator is capable of absorbing actinic radiation and producing free radicals as a result of exposure to light emitted from a visible light source.

19. The material according to claim 10 wherein said compound is an ethylenically unsaturated compound.

20. The material according to claim 10 wherein said composition is microencapsulated.

21. The material according to claim 20 wherein said photoinitiator additionally comprises an autoxidizer.

22. A photosensitive material comprising a support having a layer of a photohardenable composition on the surface thereof, said composition comprising a free radical addition polymerizable or crosslinkable compound and a photoinitiator including a cationic transition metal coordination complex and a borate anion wherein said borate anion is represented by the following formula:

##STR5## where R₁, R₂, R₃ and R₄ are the same or different and are selected from the group consisting of alkyl, aryl, aralkyl, alkaryl, alkenyl, alkynyl, alicyclic, heterocyclic, and allyl groups, and wherein said photoinitiator is capable of absorbing actinic radiation and producing free radicals which can initiate free radical polymerization of said polymerizable or crosslinkable compound.

23. The material according to claim 22 wherein said composition is microencapsulated.

24. The material according to claim 22 wherein three of said R₁, R₂, R₃ and R₄ groups are aryl and one of said R₁, R₂, R₃ and R₄ groups is alkyl.

31. The material according to claim 22 wherein said photoinitiator is capable of absorbing actinic radiation and producing free radicals as a result of exposure to light emitted from a visible light source.

32. The material according to claim 23 wherein said composition additionally comprises an image-forming agent.

33. The material according to claim 32 wherein said image-forming agent comprises a colorless color-forming agent which forms an image upon contact with a developer material.

34. The material according to claim 33 wherein said compound comprises an ethylenically unsaturated compound.

35. The material according to claim 34 wherein said microcapsules include a first set of microcapsules having a cyan image-forming agent associated therewith, a second set of microcapsules having a magenta image-forming agent associated therewith and a third set of microcapsules having a yellow image-forming agent associated therewith, wherein at least one of said first, second and third sets of microcapsules contains said photoinitiator including said cationic transition metal coordination complex and said borate anion.

36. The material according to claim 35 wherein said microcapsules upon imagewise exposure to three distinct wavelengths of actinic radiation which respectively image-wise harden said first, second and third sets of microcapsules are capable of forming a full color image on a developer material.

37. The photosensitive material of claim 36 wherein said three distinct wavelengths correspond to red, green and blue light.

25. The material according to claim 25 wherein said cationic transition metal coordination complex is a complex of a transition metal atom having a d⁶ orbital configuration and one or more ligands covalently bonded to said transition metal atom so that said complex is capable of undergoing metal to ligand charge transfer upon photoexcitation.

26. The material according to claim 25 wherein said cationic transition metal coordination complex is a complex of a transition metal atom selected from the group consisting of Re(I), Fe(II), Ru(II), Os(II), Co(III), and Ir(III).

27. The material according to claim 26 wherein said cationic transition metal coordination complex and said borate anion are present as an ion pair.

28. The material according to claim 26 wherein at least one of said ligands includes a heterocyclic group containing a nitrogen atom.

29. The material according to claim 26 wherein at least one of said ligands is selected from the group consisting of pyridine, 2,2'"'"'-bipyridine, 4,4'"'"'-dimethyl-2,2'"'"'-bipyridine, 1,10-phenanthroline, 3,4,7,8-tetramethyl-1,10-phenanthroline, 2,2'"'"',2"-terpyridine, 5,6-dimethyl-1,10-phenanthroline, 5-methyl-1,10-phenanthroline, 5-chloro-1,10-phenanthroline, 5-nitro-1,10-phenanthroline, 4,7-dimethyl-1,10-phenanthroline and 2,4,6-tri(2-pyridyl-s-triazine).

30. The material according to claim 26 wherein at least one of said ligands is a bidentate or tridentate ligand.