Liquid photopolymer useful in fabricating printing plates which are resistant to solvent based ink

• US 20030152870A1
• Filed: 02/19/2003
• Published: 08/14/2003
• Est. Priority Date: 09/24/1996
• Status: Abandoned Application

• Current Assignee: Macdermid Imaging Technology Incorporated
• Original Assignee: Macdermid Imaging Technology Incorporated
• Inventors: Huang, Misty
• Application Number:
  US10/369,440
• Publication Number:
  US 20030152870A1
• Time in Patent Office: Days
• US Class Current: 430/306
• CPC Class Codes: G03F 7/033 the binders being polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. vinyl polymers
• CPC Class Codes: G03F 7/035 the binders being polyurethanes

Abstract

A polymer based on the reaction of an excess of diisocyanate with saturated polyolefine diols to form an oligomer and further reaction of the oligomer with hydroxyacrylates or hydroxymethacrylates is discussed. The polymer is then blended with ethylenically unsaturated monomers and a photoinitiator to produce a photosensitive composition which is useful in fabricating printing plates.

Claims

1. A photosensitive resin composition comprising:

a). an ethylenically unsaturated polyurethane prepolymer of the following structure;

Y—

X

P—

X

_nY

 

wherein P is a saturated polyolefine;

 

wherein X is independently selected from the group consisting of aromatic diisocyanates and aliphatic diisocyanates;

 

wherein Y is a terminal group which has an ethylenically active portion at the outer end of said group; and

 

wherein n is an integer of from 1 to 20;

b). at least one ethylenically unsaturated monomer; and

c). at least one photopolymerization initiator.

2. A photosensitive resin composition of claim 1 wherein P is selected from the group consisting of hydrogenated polybutadienes, hydrogenated polyisoprenes, and hydrogenated, copolymers of butadiene with styrene.

3. A photosensitive resin composition of claim 1 wherein Y is independently selected from the group consisting of acrylates and methacrylates.

4. A photosensitive resin composition of claim 1 wherein the terminal group is polypropylene glycol monomethacrylate.

5. A photosensitive composition of claim 1 wherein the unsaturated polyurethane prepolymer is prepared by reacting an excess of a diisocyanate with diols selected from the group consisting of saturated polyolefine diols, a mixture of saturated polyolefine diols with unsaturated polyolefine diols, a mixture of saturated polyolefine diols with short chain diols, and a mixture of saturated polyolefine diols with polyester diols, to form an oligomer, and further reaction of the oligomer with a compound selected from the group consisting of hydroxy acrylates and hydroxymethacrylates.

6. A photosensitive composition of claim 1 wherein the prepolymer has a molecular weight greater than 3,000.

7. A photosensitive resin composition of claim 1 wherein the monomer comprises a mixture of monomers having one ethylenic group and monomers having more than one ethylenic group.

8. A photosensitive composition of claim 5 wherein the diols comprise a mixture of saturated polyolefine diols with short chain diols and wherein the short chain diols comprise less than 15 percent by weight of the total diols.

9. A photosensitive composition according to claim 8 wherein the monomer comprises a mixture of monomers having one ethylenic group and monomers having more than one ethylenic groups.

10. A process for fabricating a printing plate, said process comprising:

a). selectively contacting a photosensitive resin composition comprising;

1) an ethylenically unsaturated polyurethane prepolymer of the following structure;

Y—

X

P—

X

_nY

 

wherein P is a saturated polyolefine;

 

wherein X is independently selected from the group consisting of aromatic diisocyanates and aliphatic diisocyanates;

 

wherein Y is a terminal group which has an ethylenically active portion at the outer end of said group; and

 

wherein n is an integer of from 1 to 20;

2) at least one ethylenically unsaturated monomer; and

3) at least one photopolymerization initiator;

with actinic radiation; and

b) developing away any unpolymerized photosensitive resin.

11. A process according to claim 10 wherein P is selected from the group consisting of hydrogenated polybutadienes, hydrogenated polyisoprenes, and hydrogenated copolymers of butadiene with styrene.

12. A process according to claim 10 wherein Y is independently selected from the group consisting of acrylates and methacrylates.

13. A process according to claim 10 wherein the terminal group is polypropylene glycol monomethacrylate.

14. A process according to claim 10 wherein the unsaturated polyurethane prepolymer is prepared by reacting an excess of a diisocyanate with diols selected from the group consisting of saturated polyolefine diols, a mixture of saturated polyolefine diols with unsaturated polyolefine diols, a mixture of saturated polyolefine diols with short chain diols, and a mixture of saturated polyolefine diols with polyester diols, to form an oligomer, and further reaction of the oligomer with a compound selected from the group consisting of hydroxy acrylates and hydroxymethacrylates.

15. A process according to claim 10 wherein the prepolymer has a molecular weight greater than 3,000.

16. A process according to claim 10 wherein the monomer comprises is a mixture of monomers having one ethylenic group and monomers having more than one ethylenic group.

17. A process according to claim 14 wherein the diols comprise a mixture of saturated polyolefine diols with short claim diols and wherein the short claim diols comprise less than 15 percent by weight of the total diols.

18. A process according to claim 17 wherein the monomer comprises a mixture of monomers having one ethylenic group and monomers having more than one ethylenic group.

19. A method of forming an ethylenically unsaturated polyurethane prepolymer comprising:

a) reacting an excess of a diisocyanate with diols selected from the group consisting of saturated polyolefine diols, a mixture of saturated polydefine diols with unsaturated polyolefine diols, a mixture of saturated polyolefine diols with short claim diols and a mixture of saturated polyolefine diols with polyester diols, to form an oligomer; and

b) further reacting the oligomer with a compound selected from the group consisting of hydroxyacrylates, hydroxymethacrylates and mixtures thereof.

20. A method according to claim 19 wherein the diols comprise a mixture of saturated polyolefine diols with short chain diols and wherein the short chain diols comprise less than 15 percent by weight of the total diols.

21. A printing plate comprising the photochemical reaction product of:

(a) an ethylenically unsaturated polyurethane prepolymer which prepolymer was prepared by;

1). reacting an excess of a diisocyanate with diols selected from the group consisting of saturated polyolefine diols, a mixture of saturated polyolefine diols with unsaturated polyolefine diols, a mixture of saturated polyolefine diols with short chain diols and a mixture of saturated polyolefine diols with polyester diols, to form an oligomer; and

2). further reacting the oligomer with a compound selected from the group consisting of hydroxyacrylates, hydroxymethacrylates and mixtures thereof;

(b) at least one ethylenically unsaturated monomer; and

(c) at least one photopolymerization initiator.