Two-layer imageable element comprising thermally reversible polymers

1. An imageable element comprising:

a substrate;

a top layer comprising: (a) a first thermally imageable composition comprising a first thermally sensitive supramolecular polymer which exhibits an increased solubility in an aqueous developer solution upon exposure to heat; the first thermally sensitive supramolecular polymer comprising: at least one covalently bonded unit; and at least one thermally reversible non-covalently bonded unit, which includes a two or more centered H-bond within each non-covalently bonded unit or (b) a thermally imageable composition free of the first thermally sensitive supramolecular polymer; and

disposed between the substrate and the top layer, a bottom layer comprising a second thermally imageable composition comprising a second thermally sensitive supramolecular polymer which exhibits an increased solubility in an aqueous developer solution upon exposure to heat; the second thermally sensitive supramolecular polymer comprising: at least one covalently bonded unit; and at least one thermally reversible non-covalently bonded unit, which includes a three or more centered H-bond within each non-covalently bonded unit.

2. The imageable element of claim 1 , wherein the top layer comprises the first thermally sensitive supramolecular polymer, and wherein the thermally reversible non-covalently bonded unit in the top layer includes a four-centered H-bond.

3. The imageable element of claim 2 , wherein the four-centered H-bond in the top layer comprises two isocytosine groups.

4. The imageable element of claim 2 , wherein the four-centered H-bond comprises two N,N′-diacetyl-2,6-diaminotriazine units.

5. The imageable element of claim 1 , wherein the top layer comprises the first thermally sensitive supramolecular polymer, and wherein the covalently bonded unit in the top layer is derived from a polyfunctional material that is soluble or dispersible in an aqueous developer solution.

6. The imageable element of claim 5 , wherein the polyfunctional material is selected from the group consisting of: polyfunctional phenolic resin, acrylic resin, polyester resin, polyurethane resin and a combination thereof.

7. The imageable element of claim 6 , wherein the polyfunctional phenolic resin is selected from the group consisting of: phenol/cresol novolak, polyvinyl phenol polymer, vinyl phenol/hydxocarbyl acrylate copolymer, pyrogallol/acetone polymer and a mixture thereof.

8. The imageable element of claim 1 , wherein the top layer comprises the first thermally sensitive supramolecular polymer, and wherein the first thermally sensitive supramolecular polymer in the top layer comprises a supramolecular polymer including units having the formula:

wherein each R 1 and R 2 is independently selected from the group consisting of: hydrogen and hydrocarbyl;

wherein Y is a hydrocarbylene derived from a diisocyanate represented by the formula Y(NCO) 2 ;

wherein R 3 is a phenolic residue derived from a polyfunctional phenolic resin represented by the formula R 3 (OH) n ; and

wherein n is at least 1.

9. The imageable element of claim 8 , wherein the polyfunctional phenolic resin is selected from the group consisting of: phenol/cresol novolak, polyvinyl phenol polymer, vinyl phenol/hydrocarbyl acrylate copolymer, pyrogallol/acetone polymer and a mixture thereof.

10. The imageable element of claim 8 , wherein the diisocyanate is selected from the group consisting of: isophorone diisocyanate, methylene-bis-phenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, tetramethylxylylene diisocyanate, dimers thereof, adducts thereof with diols, and mixtures thereof.

11. The imageable element of claim 8 , wherein n is 1, 2 or 3.

12. The imageable element of claim 1 , wherein the top layer comprises the first thermally sensitive supramolecular polymer, and wherein the thermally reversible non-covalently bonded unit in the top layer includes a two-centered H-bond, which comprises two 2-pyridone groups.

13. The imageable element of claim 12 , wherein the first thermally sensitive supramolecular polymer comprises a supramolecular polymer derived from monomers represented by the formula:

wherein each R′ and R″ is independently selected from the group consisting of: H, linear, branched or cyclic alkyl, aryl, aralkyl, alkaryl, substituted aryl, alkenyl, halogen, cyano, nitro, alkoxy, aryloxy, alkoxycarbonyl, amido, acyl, aminocarbonyl, carboxylic, sulfonic, imide, N-acyl sulfonamide and phenolic hydroxy with the proviso that at least one of the R′ and R″ groups is selected from the group consisting of: carboxylic, sulfonic, imide, N-acyl sulfonamide and phenolic hydroxy; and wherein A is a bridging group.

14. The imageable element of claim 1 , wherein the top layer comprises the first thermally sensitive supramolecular polymer, and wherein the thermally reversible non-covalently bonded unit in the top layer includes a three-centered H-bond, which comprises a cyclic imide group and a 2,6-diaminotriazine group.

15. The imageable element of claim 1 , wherein the top layer comprises the first thermally sensitive supramolecular polymer, and wherein the first thermally sensitive supramolecular polymer in the top layer comprises a maleimide/styrene copolymer associated with a 4-vinyl-2,6-diaminotriazine/styrene copolymer, with the proviso that the copolymers comprise at least one base-soluble functional group selected from the group consisting of: carboxylic, sulfonic, imide, N-acyl sulfonamide and phenolic hydroxy.

16. The imageable element of claim 1 , wherein the thermally reversible non-covalently bonded unit in the bottom layer includes a four-centered H-bond.

17. The imageable element of claim 16 , wherein the four-centered H-bond in the bottom layer comprises two isocytosine groups.

18. The imageable element of claim 16 , wherein the four-centered H-bond comprises two N,N′-diacetyl-2,6-diaminotriazine units.

19. The imageable element of claim 1 , wherein the covalently bonded unit in the bottom layer is derived from a polymer, which is soluble or dispersible in an aqueous developer.

20. The imageable element of claim 19 , wherein the polymer comprises at least one base soluble functional group.

21. The imageable element of claim 20 , wherein the base soluble functional group is selected from the group consisting of: hydroxyl, carboxylic acid, sulfonic acid, phosphoric acid, imide, N-acyl sulfonamide and a combination thereof.

22. The imageable element of claim 21 , wherein the hydroxyl group is an aromatic hydroxyl group.

23. The imageable element of claim 19 , wherein the polymer is formed by polymerizing a monomer mixture comprising one or more of an ethylenically unsaturated monomer having a functional group selected from the group consisting of: hydroxyl, carboxylic acid, sulfonic acid, phosphoric acid and a combination thereof.

24. The imageable element of claim 23 , wherein the ethylenically unsaturated monomer is selected from the group consisting of compounds represented by the formulas:

and a mixture thereof;

wherein:

each Q 1 and Q 2 is independently selected from the group consisting of: hydroxyl and carboxylic acid groups;

R 4 is selected from the group consisting of: hydrogen, linear, branched or cyclic alkyl of 1 to 22 carbon atoms, linear, branched or cyclic substituted alkyl of 1 to 22 carbon atoms, aryl of 6 to 24 carbon atoms and substituted aryl of 6 to 24 atoms, wherein the substituent is selected from the group consisting of: alkyl, aryl, halogen, keto, ester, alkoxy and cyano;

X is selected from the group consisting of: O, S and NR 5 wherein R 5 selected from the group consisting of: hydrogen, linear, branched or cyclic alkyl of 1 to 22 carbon atoms, linear, branched or cyclic substituted alkyl of 1 to 22 carbon atoms, aryl of 6 to 24 carbon atoms and substituted aryl of 6 to 24 atoms, wherein the substituent is selected from the group consisting of: alkyl, aryl, halogen, keto, ester, alkoxy and cyano;

Y is selected from the group consisting of: linear, branched or cyclic alkylene of 1-22 carbon atoms, alkyleneoxyalkylene, poly(alkyleneoxy)alkylene, alkylene-NHCON(R 5 )— and a bond; and

Z is selected from the group consisting of: hydrogen, hydroxyl, carboxylic acid and groups represented by the formula:

25. The imageable element of claim 24 , wherein the ethylenically unsaturated monomer is selected from the group consisting of compounds represented by the formulas:

and a combination thereof.

26. The imageable element of claim 23 , wherein the monomer mixture further comprises an ethylenically unsaturated comonomer.

27. The imageable element of claim 26 , wherein the ethylenically unsaturated comonomer is selected from the group consisting of: acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl ether, styrene, N-phenylmaleimide, and a mixture thereof.

28. The imageable element of claim 1 , wherein the bottom layer comprises a supramolecular polymer including units having the formula:

wherein each R 1 and R 2 is independently selected from the group consisting of: hydrogen and hydrocarbyl;

wherein Y is a hydrocarbylene derived from a diisocyanate represented by the formula Y(NCO) 2 ;

wherein R 3 is a phenolic residue derived from a polyfunctional phenolic resin represented by the formula R 3 (OH) n ; and

wherein n is at least 1.

29. The imageable element of claim 28 , wherein the polyfunctional phenolic resin is selected from the group consisting of: phenol/cresol novolak, polyvinyl phenol polymer, vinyl phenol/hydrocarbyl acrylate copolymer, pyrogallol/acetone polymer and a mixture thereof.

30. The imageable element of claim 1 , further comprising a photothermal converter material.

31. The imageable element of claim 1 , wherein the thermally imageable composition that is free of the first thermally sensitive supramolecular polymer comprises a novolak resin and an infrared dye.

32. The imageable element of claim 1 , wherein the top layer comprises the first thermally sensitive supramolecular polymer, and wherein the first and the second thermally sensitive supramolecular polymers are the same.

33. The imageable element of claim 1 , wherein the top layer comprises the first thermally sensitive supramolecular polymer, and wherein the first and the second thermally sensitive supramolecular polymers are different thermally sensitive supramolecular polymers.

34. The imageable element of claim 1 , wherein the thermally reversible non-covalently bonded unit in the bottom layer includes a three-centered H-bond.

35. The imageable clement of claim 34 , wherein the three-centered H-bond comprises a cyclic imide group and a 2,6-diaminotriazine group.

36. The imageable element of claim 34 , wherein the second thermally sensitive supramolecular polymer in the bottom layer comprises a maleimide/styrene copolymer associated with a 4-vinyl-2,6-diaminotriazine/styrene copolymer, with the proviso that the copolymers comprise at least one base-soluble functional group selected from the group consisting of: carboxylic, sulfonic, imide, N-acyl sulfonamide and phenolic hydroxy.

37. An imageable element comprising:

a substrate;

a top layer comprising a first thermally imageable composition comprising a first thermally sensitive supramolecular polymer which exhibits an increased solubility in an aqueous developer solution upon exposure to heat; the first thermally sensitive supramolecular polymer comprising: at least one covalently bonded unit; and at least one thermally reversible non-covalently bonded unit, which includes a two or more centered H-bond within each non-covalently bonded unit; and

disposed between the substrate and the top layer, a bottom layer comprising a second thermally imageable composition comprising a second thermally sensitive supramolecular polymer which exhibits an increased solubility in an aqueous developer solution upon exposure to heat; the second thermally sensitive supramolecular polymer comprising: at least one covalently bonded unit; and at least one thermally reversible non-covalently bonded unit, which includes a two or more centered H-bond within each non-covalently bonded unit.

38. The imageable element of claim 37 , wherein the thermally reversible non-covalently bonded unit in the bottom layer includes a four-centered H-bond.

39. The imageable element of claim 37 , wherein the thermally reversible non-covalently bonded unit in the bottom layer includes a three-centered H-bond.

40. The imageable element of claim 37 , wherein the thermally reversible non-covalently bonded unit in the top layer includes a four-centered H-bond.

41. The imageable element of claim 37 , wherein the thermally reversible non-covalently bonded unit in the top layer includes a three-centered H-bond.

42. A method of producing an imaged element comprising the steps of:

providing an imageable element comprising a substrate; a top layer comprising: (a) a first thermally imageable composition comprising a first thermally sensitive supramolecular polymer which exhibits an increased solubility in an aqueous developer solution upon exposure to heat; the first thermally sensitive supramolecular polymer comprising: at least one covalently bonded unit; and at least one thermally reversible non-covalently bonded unit, which includes a two or more centered H-bond within each non-covalently bonded unit or (b) a thermally imageable composition free of the first thermally sensitive supramolecular polymer; and disposed between the substrate and the top layer, a bottom layer comprising a second thermally imageable composition comprising a second thermally sensitive supramolecular polymer which exhibits an increased solubility in an aqueous developer solution upon exposure to heat; the second thermally sensitive supramolecular polymer comprising: at least one covalently bonded unit; and at least one thermally reversible non-covalently bonded unit, which includes a three or more centered H-bond within each non-covalently bonded unit;

imagewise exposing the imageable element to thermal radiation to produce exposed regions; and

contacting the exposed imageable element and a developer within a period of time after the exposing step to remove the exposed regions and thereby produce the imaged element.

43. The method of claim 42 , wherein the imageable element further comprises a photothermal converting material.

44. The method of claim 42 , wherein the step of imagewise exposing the imageable element to thermal radiation is carried out using an infrared laser.

45. The method of claim 42 , wherein the period of time is up to 1 hour.

46. The method of claim 42 , wherein the thermal radiation has a pixel dwell time of not more than 100 μs.