Claims
- 1. A positive-working heat-sensitive imaging member comprising a support having thereon a heat-sensitive surface imageable layer comprising:
a) a heat-sensitive polymer comprising a heat-activatable sulfonate group, and b) a photothermal conversion material, said heat-activatable sulfonate group represented by structure I: 13wherein X is a divalent linking group, X′ is an oxygen or a sulfur atom, and Y is an imino, an alkyl group, or an amide group
- 2. The imaging member of claim 1 wherein:
a) if Y is an imino group, Y is represented by —N═CR1R2 wherein R1 and R2 are independently hydrogen, an alkyl group, an acyl group or an aromatic group, or R1 and R2 taken together can provide the atoms necessary to form alicyclic ring having from 5 to 15 carbon atoms in the ring; and b) if Y is an alkyl group, Y is represented by —CHR3CHR4R5 wherein R5 is an electron withdrawing group, and R3 and R4 are independently hydrogen or an alkyl group, and c) if Y is an amide group, Y is represented by —NHCOR wherein R is an aliphatic group, an aryl group, or a heteroaryl group.
- 3. The imaging member of claim 2 wherein:
a) if Y is said imino group, R1 and R2 taken together can provide the atoms necessary to form alicyclic ring having from 5 to 15 carbon atoms in the ring, and b) if Y is said alkyl group, R5 is sulfo, carboxy, nitro, nitrile or a substituted or unsubstituted aryl group, and R3 and R4 are independently hydrogen or an alkyl group, and c) if Y is said amide group, R is an aliphatic group having 1-12 carbon atoms, an aryl group having 6-12 carbon atoms, or a heteroaryl group having 4-12 carbon atoms.
- 4. The imaging member of claim 3 wherein:
a) if Y is said imino group, R1 and R2 together can provide the atoms necessary to form an unsubstituted alicyclic ring having from 5 to 14 carbon atoms in the ring, b) if Y is said alkyl group, R5 is sulfo or a phenyl group, and R3 and R4 are independently hydrogen or an alkyl group.
- 5. The imaging member of claim 4 wherein Y is said imino group, and X′ is an oxygen atom
- 6. The imaging member of claim 1 wherein X is a divalent aromatic group, or a group represented by —COZ(CH2)n— wherein Z is an oxy or —NH— group, and n is 1 to 6.
- 7. The imaging member of claim 6 wherein X is phenylene or —CONH(CH2)3—.
- 8. The imaging member of claim 1 wherein said heat-sensitive polymer is a vinyl polymer.
- 9. The imaging member of claim 8 wherein said heat-sensitive polymer comprises recurring units of the structure II:
- 10. The imaging member of claim 9 wherein said recurring units of structure II comprise at least 25 mol % of the total recurring units in said heat-sensitive polymer.
- 11. The imaging member of claim 10 wherein said recurring units of structure II comprise from about 40 to about 100 mol % of all recurring units in said heat-sensitive polymer.
- 12. The imaging member of claim 11 wherein said heat-sensitive polymer is a copolymer derived from two or more different ethylenically unsaturated polymerizable monomers, at least one of said monomers containing said heat-activatable sulfonate group.
- 13. The imaging member of claim 12 wherein at least one of said monomers is an acrylate, an acrylamide, an acrylonitrile, a vinylether, a styrene, vinyl acetate, a diene, vinyl pyridine or vinylpyrrolidone.
- 14. The imaging member of claim 13 wherein at least one of said monomers is an acrylate,an acrylamide, or a styrenic.
- 15. The imaging member of claim 1 wherein said photothermal conversion material is an infrared radiation absorbing material.
- 16. The imaging member of claim 15 wherein said photothermal conversion material is carbon black or one of the following IR radiation absorbing dyes:
- 17. The imaging member of claim 1 that is a lithographic printing plate.
- 18. The imaging member of claim wherein said support is a polyester or metal support.
- 19. A method of imaging comprising the steps of:
A) providing the positive-working imaging member of claim 1, and B) imagewise exposing said imaging member to thermal energy to provide exposed and unexposed areas on the surface of said imaging member, whereby said exposed areas are rendered more hydrophilic than said unexposed areas.
- 20. The method of claim 19 wherein said imagewise exposure is carried out using an IR radiation emitting laser.
- 21. The method of claim 19 wherein said imagewise exposure is carried out using a thermal printing head.
- 22. The method of claim 19 carried out without any wet processing after imaging step B.
- 23. A method of printing comprising the steps of:
A) providing the positive-working imaging member of claim 1, B) imagewise exposing said imaging member to thermal energy to provide exposed and unexposed areas on the surface of said imaging member, whereby said exposed areas are rendered more hydrophilic than said unexposed areas, and C) without any wet processing, contacting said imagewise exposed imaging member with a lithographic printing ink, and imagewise transferring said printing ink to a receiving material.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part application of copending application U.S. Ser. No. 09/399,191 for “Imaging Member Containing Switchable Polymers and Method for Use” filed Sep. 17, 1999, which is incorporated in fill herein by reference.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09399191 |
Sep 1999 |
US |
Child |
09431706 |
Nov 1999 |
US |