Ir Radical Polymerization-Type Photopolymer Plate Using Specific Binder Polymer

1 . A negative working photosensitive composition comprising:

(A) an infrared absorber,

(B) an organic boron compound,

(C) a compound having a polymerizable unsaturated group, and

(D) a binder resin having a sulfonamide or active imino group.

2 . The negative working photosensitive composition according to claim 1 , wherein the binder resin has a phenolic hydroxyl group.

3 . The negative working photosensitive composition according to claim 1 , wherein the binder resin has a polymerizable unsaturated group.

4 . The negative working photosensitive composition according to claim 2 , wherein the binder resin has a polymerizable unsaturated group.

5 . The negative working photosensitive composition according to claim 1 , wherein the infrared absorber is a near-infrared absorbing cationic dye represented by the following formula (1):

D + A −   (1)

wherein D + represents a cationic dye having an absorption in a near-infrared range, and A − represents an anion.

6 . The negative working photosensitive composition according to claim 2 , wherein the infrared absorber is a near-infrared absorbing cationic dye represented by the following formula (1):

D + A −   (1)

wherein D + represents a cationic dye having an absorption in a near-infrared range, and A − represents an anion.

7 . The negative working photosensitive composition according to claim 3 , wherein the infrared absorber is a near-infrared absorbing cationic dye represented by the following formula (1):

D + A −   (1)

wherein D + represents a cationic dye having an absorption in a near infrared range, and A − represents an anion.

8 . The negative working photosensitive composition according to claim 1 , wherein the organic boron compound is an ammonium salt of a quaternary boron anion represented by the following formula (2):

[Chemical Formula 1]

wherein R 1 , R 2 , R 3 and R 4 each independently represents an alkyl group, an aryl group, an alkaryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group, at least one of R 1 , R 2 , R 3 and R 4 is an alkyl group having 1 to 8 carbon atoms, and R 5 , R 6 , R 7 and R 8 each independently represents a hydrogen atom, an alkyl group, an aryl group, an allyl group, an alkaryl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group.

9 . The negative working photosensitive composition according to claim 2 , wherein the organic boron compound is an ammonium salt of a quaternary boron anion represented by the following formula (2):

[Chemical Formula 2]

wherein R 1 , R 2 , R 3 and R 4 each independently represents an alkyl group, an aryl group, an alkaryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl

group, an alicyclic group, or a saturated or unsaturated heterocyclic group, at least one of R 1 , R 2 , R 3 and R 4 is an alkyl group having 1 to 8 carbon atoms, and R 5 , R 6 , R 7 and R 8 each independently represents a hydrogen atom, an alkyl group, an aryl group, an allyl group, an alkaryl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group.

10 . The negative working photosensitive composition according to claim 3 , wherein the organic boron compound is an ammonium salt of a quaternary boron anion represented by the following formula (2):

[Chemical Formula 3]

wherein R 1 , R 2 , R 3 and R 4 each independently represents an alkyl group, an aryl group, an alkaryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group, at least one of R 1 , R 2 , R 3 and R 4 is an alkyl group having 1 to 8 carbon atoms, and R 5 , R 6 , R 7 and R 8 each independently represents a hydrogen atom, an alkyl group, an aryl group, an allyl group, an alkaryl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group.

11 . The negative working photosensitive composition according to claim 5 , wherein the organic boron compound is an ammonium salt of a quaternary boron anion represented by the following formula (2):

[Chemical Formula 4]

wherein R 1 , R 2 , R 3 and R 4 each independently represents an alkyl group, an aryl group, an alkaryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group, at least one of R 1 , R 2 , R 3 and R 4 is an alkyl group having 1 to 8 carbon atoms, and R 5 , R 6 , R 7 and R 8 each independently represents a hydrogen atom, an alkyl group, an aryl group, an allyl group, an alkaryl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group.

12 . The negative working photosensitive composition according to claim 6 , wherein the organic boron compound is an ammonium salt of a quaternary boron anion represented by the following formula (2):

[Chemical Formula 5]

wherein R 1 , R 2 , R 3 and R 4 each independently represents an alkyl group, an aryl group, an alkaryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group, at least one of R 1 , R 2 , R 3 and R 4 is an alkyl group having 1 to 8 carbon atoms, and R 5 , R 6 , R 7 and R 8 each independently represents a hydrogen atom, an alkyl group, an aryl group, an allyl group, an alkaryl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group.

13 . The negative working photosensitive composition according to claim 7 , wherein the organic boron compound is an ammonium salt of a quaternary boron anion represented by the following formula (2):

[Chemical Formula 6]

wherein R 1 , R 2 , R 3 and R 4 each independently represents an alkyl group, an aryl group, an alkaryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group, at least one of R 1 , R 2 , R 3 and R 4 is an alkyl group having 1 to 8 carbon atoms, and R 5 , R 6 , R 7 and R 8 each independently represents a hydrogen atom, an alkyl group, an aryl group, an allyl group, an alkaryl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group.

14 . A negative working photosensitive lithographic printing plate precursor comprising a substrate and a photosensitive layer formed on the substrate,

said photosensitive layer comprising

(A) an infrared absorber,

(B) an organic boron compound,

(C) a compound having a polymerizable unsaturated group, and

(D) a binder resin having a sulfonamide or active imino group.

15 . The printing plate precursor of claim 14 wherein the binder resin has a phenolic hydroxyl group.

16 . The printing plate precursor of claim 14 wherein the binder resin has a polymerizable unsaturated group.

17 . The printing plate precursor of claim 14 wherein the infrared absorber is a near-infrared absorbing cationic dye represented by the following formula (1):

D + A −   (1)

wherein D + represents a cationic dye having an absorption in a near-infrared range, and A − represents an anion.

18 . The printing plate precursor of claim 14 wherein the organic boron compound is an ammonium salt of a quaternary boron anion represented by the following formula (2):

[Chemical Formula 1]

wherein R 1 , R 2 , R 3 and R 4 each independently represents an alkyl group, an aryl group, an alkaryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group, at least one of R 1 , R 2 , R 3 and R 4 is an alkyl group having 1 to 8 carbon atoms, and R 5 , R 6 , R 7 and R 8 each independently represents a hydrogen atom, an alkyl group, an aryl group, an allyl group, an alkaryl group, an aralkyl group, an alkenyl group, an alkynyl group, an alicyclic group, or a saturated or unsaturated heterocyclic group.

19 . A method of forming a printing plate comprising imaging and developing the printing plate precursor of claim 14.