Claims
- 1. A method for making a lithographic printing plate, comprising:exposing a positive photosensitive lithographic printing plate comprising a positive photosensitive composition on a support, wherein the positive photosensitive composition comprises (a) a photo-thermal conversion material, and (b) a high molecular compound wherein said high molecular compound (b) has a solubility in an aqueous alkali developer which changes as a result of a change, other than a chemical change, in said high molecular compound (b); wherein the solubility in an aqueous alkali developer of said composition is greater in a photo-thermally exposed portion than a non-exposed portion; wherein said exposing is accomplished by means of a light ray belonging to a wavelength region of from 650 to 1300 nm and having a light intensity of at least 2×106 mJ/s·cm2, and developing the positive photosensitive lithographic printing plate with an alkali developer, wherein said photosensitive composition has substantially no photosensitivity to ultraviolet light.
- 2. The method of claim 1, wherein the light intensity is at least 1×107 mJ/s·cm2.
- 3. The method of claim 1wherein said exposing is accomplished by means of a light ray belonging to a wavelength region of from 650 to 1100 nm.
- 4. The method for making a lithographic printing plate according to claim 1, wherein the light source for the light ray is a semiconductor laser or a YAG laser.
- 5. The method of claim 1 wherein the positive photosensitive composition further contains (c) a solubility-suppressing agent, wherein said solubility-suppressing agent (c) is capable of lowering the dissolution rate of a blend of component (a) and component (b) in said aqueous alkali developer.
- 6. The method of claim 5, wherein the solubility-suppressing agent (c) is at least one functional compound selected from the group consisting of a sulfonic acid ester, a phosphoric acid ester, an aromatic carboxylic acid ester, a carboxylic anhydride, an aromatic ketone, an aromatic aldehyde, an aromatic amine, an aromatic ether, a substituted compound thereof and a polymeric material having a structure in which said functional compound is combined into a polymer or a resin.
- 7. A method for making a lithographic printing plate, comprising:exposing a positive photosensitive lithographic printing plate comprising a positive photosensitive composition on a support, wherein the positive photosensitive composition comprises (a) a photo-thermal conversion material, and (b) a high molecular compound wherein said high molecular compound (b) has a solubility in an aqueous alkali developer which changes as a result of a change, other than a chemical change, in said high molecular compound (b); wherein the solubility in an aqueous alkali developer of said composition is greater in a photo-thermally exposed portion than a non-exposed portion; wherein said exposing is accomplished by means of a light ray belonging to a wavelength region of from 650 to 1300 nm and having a light intensity of at least 2×106 mJ/s·cm2, and developing the positive photosensitive lithographic printing plate with an alkali developer, wherein the positive photosensitive composition further contains (c) a solubility-suppressing agent, wherein said solubility-suppressing agent (c) is capable of lowering the dissolution rate of a blend of component (a) and component (b) in said aqueous alkali developer, and wherein the solubility-suppressing agent (c) is a compound having substantially no photosensitivity to ultraviolet light.
- 8. A method for making a positive photosensitive lithographic printing plate comprising exposing a positive photosensitive lithographic printing plate having a positive photosensitive composition on a support, said photosensitive composition comprising(a) a photo-thermal conversion material; and (b) a high molecular compound; wherein the solubility in an aqueous alkali developer of said composition is greater in a photo-thermally exposed portion than a non-exposed portion; with the proviso that B<A, where A is the solubility in an alkali developer at an exposed portion of the composition, and B is an alkali solubility after heating of the exposed portion;wherein said exposing is accomplished by means of a light ray belonging to a wavelength region of from 650 to 1300 nm and having a light intensity of at least 2×106 mJ/s·cm2, and developing the positive photosensitive lithographic printing plate with an alkali developer, wherein said photosensitive composition has substantially no photosensitivity to ultraviolet light.
- 9. The method of claim 8 wherein the light intensity is at least 1×107 mJ/s·cm2.
- 10. The method of claim 8 wherein said exposing is accomplished by means of a light ray belonging to a wavelength region of from 650 to 1100 nm.
- 11. The method for making a positive photosensitive lithographic printing plate according to claim 8, wherein the light source for the light ray is a semiconductor laser or a YAG laser.
- 12. The method of claim 8 wherein the positive photosensitive composition further contains (c), a solubility-suppressing agent, wherein said solubility-suppressing agent (c) is capable of lowering the dissolution rate of a blend of component (a) and component (b) in said aqueous alkali developer.
- 13. The method of claim 12 wherein the solubility-suppressing agent (c) is at least one functional compound selected from the group consisting of a sulfonic acid ester, a phosphoric acid ester, an aromatic carboxylic acid ester, a carboxylic anhydride, an aromatic ketone, an aromatic aldehyde, an aromatic amine, an aromatic ether, a substituted compound thereof and a polymeric material having a structure in which said functional compound is combined into a polymer or a resin.
- 14. The method of claim 12 wherein the solubility-suppressing agent (c) is a compound having substantially no photosensitivity to ultraviolet light.
- 15. The method of claim 1, wherein the photo-thermal conversion material (a) is a light-absorbing dye having an absorption band, covering a part or the whole, of a wavelength region of from 650 to 1100 nm.
- 16. The method of claim 1, wherein the photo-thermal conversion material (a) is at least one compound selected from the group consisting of a cyanine dye, a polymethine dye, a squarilium dye, a croconium dye, a pyrylium dye and a thiopyrylium dye.
- 17. The method of claim 1, wherein the photo-thermal conversion material (a) is at least one compound selected from the group consisting of a cyanine dye of formula (I), wherein each of R1 and R2 is a C1-8 alkyl group which may have a substituent, wherein the substituent is a phenyl group, a phenoxy group, an alkoxy group, a sulfonic acid group, or a carboxyl group; Q1 is a heptamethine group which may have a substitutent, wherein the substituent is a C1-8 alkyl group, a halogen atom or an amino group, or the heptamethine group may contain a cyclohexene ring or a cyclopentene ring having a substituent, formed by mutual bonding of substituents on two methine carbon atoms of the heptamethine group, wherein the substituent is a C1-6 alkyl group or a halogen atom; each of m1 and m2 is 0 or 1; each of Z1 and Z2 is a group of atoms required for forming a nitrogen-containing heterocyclic ring; and X− is a counter anion; a polymethine dye of formula (II), wherein each of R3 to R6 is a C1-8 alkyl group; each of Z4 and Z5 is an aryl group which may have a substituent, wherein the aryl group is a phenyl group, a naphthyl group, a furyl group or a thienyl group, and the substituent is a C1-4 alkyl group, a C1-8 dialkylamino group, a C1-8 alkoxy group and a halogen atom; Q2 is a trimethine group or a pentamethine group; and X− is a counter anion; and a pyrylium or thiopyrylium dye of formula (III) wherein each of Y1 and Y2 is an oxygen atom or a sulfur atom, each of R7, R8, R15 and R16 is a phenyl group or a naphthyl group which may have a substituent, wherein the substituent is a C1-8 alkyl group or a C1-8 alkoxy group; each of l1 and l2 which are independent of each other, is 0 or 1; each of R9 to R14 is a hydrogen atom or a C1-8 alkyl group, or R9 and R10, R11, and R12, or R13 and R14, are bonded to each other to form a linking group of formula (IV): where each of R17 to R19 is a hydrogen atom or a C1-6 alkyl group, and n is 0 or 1; Z3 is a halogen atom or a hydrogen atom; and X− is a counter anion.
- 18. The method of claim 17, wherein the counter ion X− is selected from the group consisting of Cl−, Br−, I−, ClO4−, BF4−, PF6−, benzenesulfonic acid anion, p-toluenesulfonic acid anion, naphthalene-1-sulfonic acid anion and acetic acid anion.
- 19. The method of claim 1, wherein the high molecular compound (b) comprises a polymer or a resin.
- 20. The method of claim 1, wherein the high molecular compound (b) comprises a novolak resin, a polyvinyl phenol resin or a mixture thereof.
- 21. The method of claim 1, wherein the high molecular compound (b) is a novolak resin.
- 22. The method of claim 1, wherein said composition is in the absence of a compound susceptible to a photochemical sensitizing effect by the photo-thermal conversion material.
- 23. The method of claim 5, wherein said solubility-suppressing agent (c) is a compound not susceptible to a photochemical sensitizing effect by the light source used to effect photo-thermal conversion material.
- 24. The method of claim 5, wherein the solubility-suppressing agent (c) lowers the dissolution rate of the blend of component (a) and component (b) to a level of up to 80%.
- 25. The method of claim 5, wherein the solubility-suppressing agent (c) lowers the dissolution rate of the blend of component (a) and component (b) to a level of up to 50%.
- 26. The method of claim 5, wherein the solubility-suppressing agent (c) lowers the dissolution rate of the blend of component (a) and component (b) to a level of up to 30%.
- 27. The method of claim 8, wherein the photo-thermal conversion material (a) is a light-absorbing dye having an absorption band, covering a part or the whole, of a wavelength in a region of from 650 to 1100 nm.
- 28. The method of claim 8, wherein the photo-thermal conversion material (a) is at least one compound selected from the group consisting of a cyanine dye, a polymethine dye, a squarilium dye, a croconium dye, a pyrylium dye and a thiopyrylium dye.
- 29. The method of claim 8, wherein the photo-thermal conversion material (a) is at least one compound selected from the group consisting of a cyanine dye of formula (I), wherein each of R1 and R2 is a C1-8 alkyl group which may have a substituent, wherein the substitutent is a phenyl group, a phenoxy group, an alkoxy group, a sulfonic acid group, or a carboxyl group; Q1 is a heptamethine group which may have a substitutent, wherein the substituent is a C1-8 alkyl group, a halogen atom or an amino group, or the heptamethine group may contain a cyclohexene ring or a cyclopentene ring having a substituent, formed by mutual bonding of substituents on two methine carbon atoms of the heptamethine group, wherein the substituent is a C1-6 alkyl group or a halogen atom; each of m1 and m2 is 0 or 1; each of Z1 and Z2 is a group of atoms required for forming a nitrogen-containing heterocyclic ring; and X− is a counter anion;a polymethine dye of formula (II), wherein each of R3 to R6 is a C1-8 alkyl group; each of Z4 and Z5 is an aryl group which may have a substituent, wherein the aryl group is a phenyl group, a naphthyl group, a furyl group or a thienyl group, and the substituent is a C1-4 alkyl group, a C1-8 dialkylamino group, a C1-8 alkoxy group and a halogen atom; Q2 is a trimethine group or a pentamethine group; and X− is a counter anion; and a pyrylium or thiopyrylium dye of formula (III) wherein each of Y1 and Y2 is an oxygen atom or a sulfur atom, each of R7, R8, R15 and R16 is a phenyl group or a naphthyl group which may have a substituent, wherein the substituent is a C1-8 alkyl group or a C1-8 alkoxy group; each of l1 and l2 which are independent of each other, is 0 or 1; each of R9 to R14 is a hydrogen atom or a C1-8 alkyl group, or R9 and R10, R11, and R12, or R13 and R14, are bonded to each other to form a linking group of formula (IV): where each of R17 to R19 is a hydrogen atom or a C1-6 alkyl group, and n is 0 or 1; Z3 is a halogen atom or a hydrogen atom; and X− is a counter anion.
- 30. The method of claim 29, wherein the counter ion X− is selected from the group consisting of Cl−, Br−, I−, ClO4−, BF4−, PF6−, benzenesulfonic acid anion, p-toluenesulfonic acid anion, naphthalene-1-sulfonic acid anion and acetic acid anion.
- 31. The method of claim 8, wherein the high molecular compound comprises a polymer or a resin.
- 32. The method of claim 8, wherein the high molecular compound comprises a novolak resin, a polyvinyl phenol resin or a mixture thereof.
- 33. The method of claim 8, wherein the high molecular compound is a novolak resin.
- 34. The method of claim 8, wherein said composition is in the absence of a compound susceptible to a photochemical sensitizing effect by the photo-thermal conversion material.
- 35. The method of claim 12, wherein said solubility-suppressing agent (c) is a compound not susceptible to a photochemical sensitizing effect by the light source used to effect photo-thermal conversion.
- 36. The method of claim 12, wherein the solubility-suppressing agent (c) lowers the dissolution rate of the blend of component (a) and component (b) to a level of up to 80%.
- 37. The method of claim 12, wherein the solubility-suppressing agent (c) lowers the dissolution rate of the blend of component (a) and component (b) to a level of up to 50%.
- 38. The method of claim 12, wherein the solubility-suppressing agent (c) lowers the dissolution rate of the blend of component (a) and component (b) to a level of up to 30%.
- 39. The method of claim 1 wherein the positive photosensitive composition contains no photo-acid generator.
- 40. The method of claim 8 wherein the positive photosensitive composition contains no photo-acid generator.
Priority Claims (3)
Number |
Date |
Country |
Kind |
8-207013 |
Aug 1996 |
JP |
|
8-302722 |
Nov 1996 |
JP |
|
9-9264 |
Jan 1997 |
JP |
|
Parent Case Info
This application is a Division of application Ser. No. 08/906,258 filed on Aug. 5, 1997, now U.S. Pat. No. 6,326,122.
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