Infrared absorbing compounds and their use in photoimageable elements

1. An infrared absorbing compound, the compound having the structure:

in which:

R 1 and R 2 are each independently an alkyl group, an aryl group, an aralkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an aminoalkyl group, a carboxyalkyl group, or a sulfoalkyl group;

Y is hydrogen, halo, alkyl, diphenylamino, or phenylthio;

Z 1 and Z 2 are each independently a benzo group or a naphtho group;

Z 3 is two hydrogen atoms, a cyclohexene residue, or a cyclopentene residue;

X 1 and X 2 are each independently S, O, NH, CH 2 , or C(CH 3 ) 2 ;

A is selected from the group consisting of 5-isatinsulfonate, 10-camphorsulfonate, and 4,5-dihydroxy-1,3-benzenedisulfonate; and

n is 1 when A is 10-camphorsulfonate, and n is 2 when A is 5-isatinsulfonate or 4,5-dihydroxy-1,3-benzenedisulfonate.

2. The infrared absorbing compound of claim 1 in which A is 5-isatinsulfonate.

3. The infrared absorbing compound of claim 1 in which A is 10-camphorsulfonate.

4. The infrared absorbing compound of claim 1 in which A is 4,5-dihydroxy-1,3-benzenedisulfonate.

5. The infrared absorbing compound of claim 1 in which R 1 and R 2 are the same; Z 1 and Z 2 are the same; and X 1 and X 2 are the same.

6. The infrared absorbing compound of claim 5 in which:

R 1 and R 2 are each an alkyl group of one to four carbon atoms;

Y is hydrogen, chloro, phenylthio, or diphenylamino;

Z 3 is cyclohexene residue or a cyclopentene residue; and

X 1 and X 2 are each C(CH 3 ) 2 .

7. The infrared absorbing compound of claim 6 in which A is 5-isatinsulfonate.

8. The infrared absorbing compound of claim 6 in which A is 10-camphorsulfonate.

9. The infrared absorbing compound of claim 6 in which A is 4,5-dihydroxy-1,3-benzenedisulfonate.

10. An imageable element, the imageable element comprising a layer of an imageable composition over a substrate,

in which the imageable element comprises an infrared absorbing compound having the structure:

in which:

R 1 and R 2 are each independently an alkyl group, an aryl group, an aralkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an aminoalkyl group, a carboxyalkyl group, or a sulfoalkyl group;

Y is hydrogen, halo, alkyl, diphenylamino, or phenylthio;

Z 1 and Z 2 are each independently a benzo group or a naphtho group;

Z 3 is two hydrogen atoms, a cyclohexene residue, or a cyclopentene residue;

X 1 and X 2 are each independently S, O, NH, CH 2 , or C(CH 3 ) 2 ;

A is selected from the group consisting of 5-isatinsulfonate, 10-camphorsulfonate, and 4,5-dihydroxy-1,3-benzenedisulfonate; and

n is 1 when A is 10-camphorsulfonate, and n is 2 when A is 5-isatinsulfonate or 4,5-dihydroxy-1,3-benzenedisulfonate.

11. The element of claim 10 in which the imageable composition comprises the infrared absorbing compound, an acid generator; an acid activatable crosslinking agent; and a polymeric binder.

12. The element of claim 11 in which the acid activatable crosslinking agent is a methylol melamine resin or a resole rein.

13. The element of claim 11 in which the polymeric binder is a novolac resin.

14. The element of claim 11 in which the polymeric binder is selected from the group consisting of:

(a) copolymers that contain about 25 to about 75 mol % of N-phenylmaleimide; about 10 to about 50 mol % of methacrylamide; and about 5 to about 30 mol % of methacrylic acid;

(b) copolymers that contain a reactive pendent group capable of undergoing acid crosslinking, the reactive pendent group selected from the group consisting of carboxylic acid, sulfonamide, and alkoxymethyl amide;

(c) functionalized polyvinyl alcohols in which 10 mol % to 60 mol % of the hydroxyl groups are unfunctionalized; about 1 mol % to 30 mol % of the hydroxyl groups are functionalized with —OCOR 3 groups; 5 mol % to 60 mol % of the hydroxyl groups are functionalized with an aldehyde of the structure R 4 CHO; 0 mol % to 60 mol % of the hydroxyl groups are functionalized with an aldehyde of the structure R 5 CHO; and 1 mol % to 40 mol % of the hydroxyl groups are functionalized with an aldehyde that contains a carboxyl group; in which R 3 , R 4 , and R 5 are each hydrogen or an alkyl group of one to eighteen carbon atoms; and

(d) sulfonyl amido substituted phenolic resins of the structure:

in which:

each R 7 is hydrogen or —C(O)—NH—SO2—R 11 with the proviso that at least 20 mol % of the R 7 groups are —C(O)—NH—SO2—R 11 R 11 is alkyl, aryl, or aralkyl; each R 8 is hydrogen or alkyl; each R 9 and R 10 is each independently hydrogen or alkyl; and n is greater than 20.

15. The element of claim 11 in which the acid generator is a salt in which the cation is iodonium, sulfonium, or diazonium, and the anion is an organic sulfate, an alkyl sulfonate, an alkyl sulfonate, or an organic thiosulfate.

16. The element of claim 11 in which R 1 and R 2 are the same; Z 1 and Z 2 are the same; and X 1 and X 2 are the same.

17. The element of claim 11 in which:

R 1 and R 2 are each independently an alkyl group, an aryl group, an aralkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an aminoalkyl group, a carboxyalkyl group, or a sulfoalkyl group;

Y is hydrogen, chloro, phenylthio, or diphenylamino;

Z 3 is cyclohexene residue or a cyclopentene residue; and

X 1 and X 2 are each C(CH 3 ) 2 .

18. The element of claim 17 in which the polymeric binder is selected from the group consisting of:

(a) copolymers that contain about 25 to about 75 mol % of N-phenylmaleimide; about 10 to about 50 mol % of methacrylamide; and about 5 to about 30 mol % of methacrylic acid;

(b) copolymers that contain a reactive pendent group capable of undergoing acid crosslinking, the reactive pendent group selected from the group consisting of carboxylic acid, sulfonamide, and alkoxymethyl amide;

(c) functionalized polyvinyl alcohols in which 10 mol % to 60 mol % of the hydroxyl groups are unfunctionalized; about 1 mol % to 30 mol % of the hydroxyl groups are functionalized with —OCOR 3 groups; 5 mol % to 60 mol % of the hydroxyl groups are functionalized with an aldehyde of the structure R 4 CHO; 0 mol % to 60 mol % of the hydroxyl groups are functionalized with an aldehyde of the structure R 5 CHO; and 1 mol % to 40 mol % of the hydroxyl groups are functionalized with an aldehyde that contains a carboxyl group; in which R 3 , R 4 , and R 5 are each hydrogen or an alkyl group of one to eighteen carbon atoms; and

(d) sulfonyl amido substituted phenolic resins of the structure:

in which:

each R 7 is hydrogen or —C(O)—NH—SO2—R 11 with the proviso that at least 20 mol % of the R 7 groups are —C(O)—NH—SO2—R 11 ; R 11 is alkyl, aryl, or aralkyl; each R 8 is hydrogen or alkyl; each R 9 and R 10 is each independently hydrogen or alkyl; and n is greater than 20.

19. The element of claim 18 in which the acid generator is a salt in which the cation is iodonium, sulfonium, or diazonium, and the anion is an organic sulfate, an alkyl sulfonate, an aryl sulfonate, or an organic thiosulfate.

20. The element of claim 19 in which A is 5-isatinsulfonate.

21. The element of claim 19 in which A is 10-camphorsulfonate.

22. The element of claim 19 in which A is 4,5-dihydroxy-1,3-benzenedisulfonate.

23. The element of claim 11 in which A is 5-isatinsulfonate.

24. The element of claim 11 in which A is 10-camphorsulfonate.

25. The element of claim 11 in which A is 4,5-dihydroxy-1,3-benzenedisulfonate.

26. The element of claim 10 in which the element additionally comprises an underlayer between the imageable layer and the substrate.

27. The element of claim 26 in which the infrared absorbing compound is either in the underlayer or in an absorber layer between the imageable layer and the underlayer.

28. A method for forming an image, the method comprising, in order, the steps of:

thermally imaging an imageable element comprising a layer of an imageable composition on a substrate and forming an imaged imageable element comprising imaged and unimaged regions in the layer of imageable composition; and

developing the imaged imageable element in a developer and removing the unimaged regions;

in which:

the imageable composition comprises an infrared absorbing compound, an acid generator; an acid activatable crosslinking agent; and a polymeric binder; and

the infrared absorbing compound has the structure:

in which:

R 1 and R 2 are each independently an alkyl group, an aryl group, an aralkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an aminoalkyl group, a carboxyalkyl group, or a sulfoalkyl group;

Y is hydrogen, halo, alkyl, diphenylamino, or phenylthio;

Z 1 and Z 2 are each independently a benzo group or a naphtho group;

Z 3 is two hydrogen atoms, a cyclohexene residue, or a cyclopentene residue;

X 1 and X 2 are each independently S, O, NH, CH 2 , or C(CH 3 ) 2 ;

A is selected from the group consisting of 5-isatinsulfonate, 10-camphorsulfonate, and 4,5-dihydroxy-1,3-benzenedisulfonate; and

n is 1 when A is 5-isatinsulfonate or 10-camphorsulfonate, and n is 2 when A is 4,5-dihydroxy-1,3-benzenedisulfonate.

29. The method of claim 28 additionally comprising the step of heating the imaged imageable element after imaging and before developing.

30. The method of claim 28 in which imaging is carried out with infrared radiation.

31. The method of claim 28 in which R 1 and R 2 are the same; Z 1 and Z 2 are the same; and X 1 and X 2 are the same.

32. A method for forming an image, the method comprising, in order, the steps of:

thermally imaging an imageable element comprising a layer of an imageable composition on a substrate and forming an imaged imageable element comprising imaged and unimaged regions in the layer of imageable composition; and

developing the imaged imageable element in a solvent based developer and removing the unimaged regions;

in which:

the solvent based developer comprises about 0.5 wt % to about 15 wt %, based on the weight of the developer, of an organic solvent and the developer has a pH of less than 10.5;

the imageable composition comprises an infrared absorbing compound, an acid generator, an acid activatable crosslinking agent, and a polymeric binder; and

the polymeric binder is:

(a) a copolymer that contains about 25 to about 75 mol % of N-phenylmaleimide; about 10 to about 50 mol % of methacrylamide; and about 5 to about 30 mol % of methacrylic acid;

(b) a copolymer that contains a reactive pendent group capable of undergoing acid crosslinking, the reactive pendent group selected from the group consisting of carboxylic acid, sulfonamide, and alkoxymethyl amide;

(c) a functionalized polyvinyl alcohol in which 10 mol % to 60 mol % of the hydroxyl groups are unfunctionalized; about 1 mol % to 30 mol % of the hydroxyl groups are functionalized with —OCOR 3 groups; 5 mol % to 60 mol % of the hydroxyl groups are functionalized with an aldehyde of the structure R 4 CHO; 0 mol % to 60 mol % of the hydroxyl groups are functionalized with an aldehyde of the structure R 5 CHO; and 1 mol % to 40 mol % of the hydroxyl groups are functionalized with an aldehyde that contains a carboxyl group; in which R 3 , R 4 , and R 5 are each hydrogen or an alkyl group of one to eighteen carbon atoms; or

(d) a sulfonyl amido substituted phenolic resin of the structure:

in which:

each R 7 is hydrogen or —C(O)—NH—SO2—R 11 with the proviso that at least 20 mol % of the R 7 groups are —C(O)—NH—SO2—R 11 ; R 11 is alkyl, aryl, or aralkyl; each R 8 is hydrogen or alkyl; each R 9 and R 10 is each independently hydrogen or alkyl; and n is greater than 20.

33. The method of claim 32 additionally comprising the step of heating the imaged imageable element after imaging and before developing.

34. The method of claim 33 in which the polymeric binder is (a), the copolymer that contains about 25 to about 75 mol % of N-phenylmaleimide; about 10 to about 50 mol % of methacrylamide; and about 5 to about 30 mol % of methacrylic acid.

35. The method of claim 33 in which the polymeric binder is (b), the copolymer that contains a reactive pendent group capable of undergoing acid crosslinking.

36. The method of claim 33 in which the polymeric binder is (c), the functionalized polyvinyl alcohol.

37. The method of claim 33 in which the polymeric binder is (d), the sulfonyl amido substituted phenolic resin of the structure:

38. The method of claim 32 in which the binder is the copolymer that contain about 25 to about 75 mol % of N-phenylmaleimide; about 10 to about 50 mol % of methacrylamide; and about 5 to about 30 mol % of methacrylic acid.

39. The method of claim 32 in which the binder is the copolymer that contain a reactive pendent group capable of undergoing acid crosslinking.

40. The method of claim 32 in which the binder is the functionalized polyvinyl alcohol.

41. The method of claim 32 in which the binder is the sulfonyl amido substituted phenolic resin.

42. A method for forming an image, the method comprising, in order, the steps of:

thermally imaging an imageable element comprising a layer of an imageable composition on a substrate and forming an imaged imageable element comprising imaged and unimaged regions in the layer of imageable composition; and

developing the imaged imageable element in a solvent based developer and removing the unimaged regions;

in which:

the solvent based developer comprises about 0.5 wt % to about 15 wt %, based on the weight of the developer, of an organic solvent and the developer has a pH of less than 10.5;

the imageable composition comprises an infrared absorbing compound, an acid generator, an acid activatable crosslinking agent, and a polymeric binder;

the polymeric binder is:

(a) a copolymer that contains about 25 to about 75 mol % of N-phenylmaleimide; about 10 to about 50 mol % of methacrylamide; and about 5 to about 30 mol % of methacrylic acid;

(b) a copolymer that contains a reactive pendent group capable of undergoing acid crosslinking, the reactive pendent group selected from the group consisting of carboxylic acid, sulfonamide, and alkoxymethyl amide;

(c) a functionalized polyvinyl alcohol in which 10 mol % to 60 mol % of the hydroxyl groups are unfunctionalized; about 1 mol % to 30 mol % of the hydroxyl groups are functionalized with —OCOR 3 groups; 5 mol % to 60 mol % of the hydroxyl groups are functionalized with an aldehyde of the structure R 4 CHO; 0 mol % to 60 mol % of the hydroxyl groups are functionalized with an aldehyde of the structure R 5 CHO; and 1 mol % to 40 mol % of the hydroxyl groups are functionalized with an aldehyde that contains a carboxyl group; in which R 3 , R 4 , are R 5 each hydrogen or an alkyl group of one to eighteen carbon atoms; or

(d) a sulfonyl amido substituted phenolic resin of the structure:

in which each R 7 is hydrogen or —C(O)—NH—SO2-R 11 with the proviso that at least 20 mol % of the R 7 groups are —C(O)—NH—SO2—R 11 ; R 11 is alkyl, aryl, or aralkyl; each R 8 is hydrogen or alkyl; each R 9 and R 10 is each independently hydrogen or alkyl; and n is greater than 20; and

the infrared absorbing compound has the structure:

in which:

R 1 and R 2 are each independently an alkyl group, an aryl group, an aralkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an aminoalkyl group, a carboxyalkyl group, or a sulfoalkyl group;

Y is hydrogen, halo, alkyl, diphenylamino, or phenylthio;

Z 1 and Z 2 are each independently a benzo group or a naphtho group;

Z 3 is two hydrogen atoms, a cyclohexene residue, or a cyclopentene residue;

X 1 and X 2 are each independently S, O, NH, CH 2 , or C(CH 3 ) 2 ;

A is selected from the group consisting of 5-isatinsulfonate, 10-camphorsulfonate, and 4,5-dihydroxy-1,3-benzenedisulfonate; and

n is 1 when A is 5-isatinsulfonate or 10-camphorsulfonate, and n is 2 when A is 4,5-dihydroxy-1,3-benzenedisulfonate.

43. The method of claim 42 in which imaging is carried out with infrared radiation.

44. The method of claim 43 in which R 1 and R 2 are the same; Z 1 and Z 2 are the same; and X 1 and X 2 are the same.