Ink composition, inkjet recording method, printed material, production method of a planographic printing plate and planographic printing plate

1. An ink composition comprising (a) a cationically polymerizable oxetane compound represented by one of the following formulae (1)-(5):

wherein R a1 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group, a furyl group or a thienyl group, provided that when there are two R a1 groups in the molecule, they may be the same as or different from each other;

R a2 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aromatic ring-containing group, an alkylcarbonyl group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, or an N-alkylcarbamoyl group having 2 to 6 carbon atoms;

R a3 represents a linear or branched alkylene group, a linear or branched poly(alkyleneoxy) group, a linear or branched unsaturated hydrocarbon group, a carbonyl group or a carbonyl group-containing alkylene group, a carboxyl group-containing alkylene group, a carbamoyl group-containing alkylene group, or one of the following groups:

wherein R a4 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a nitro group, a cyano group, a mercapto group, a lower alkylcarboxyl group, a carboxyl group, or a carbamoyl group;

R a5 represents an oxygen or sulfur atom, a methylene group, NH, SO, SO 2 , C(CF 3 ) 2 , or C(CH 3 ) 2 ;

R a6 represents an alkyl group having 1 to 4 carbon atoms or an aryl group;

n is an integer of 0 to 2,000;

R a7 represents an alkyl group having 1 to 4 carbon atoms, an aryl group, or a monovalent group having the following structure:

wherein R a8 represents an alkyl group having 1 to 4 carbon atoms or an aryl group;

m is an integer of 0 to 100;

R a9 represents a connecting group;

j is 3 or 4;

R a11 represents an alkyl group having 1 to 4 carbon atoms or a trialkylsilyl group; and

r is 1 to 4,

(b) a compound that generates an acid upon irradiation with a radiation ray represented by one of the following formulae (b1) and (b2):

wherein R 201 , R 202 and R 203 each independently represents an organic group, and any two of R 201 -R 203 may bind to each other to form a ring; R 204 and R 205 each independently represents an aryl group, an alkyl group or a cycloalkyl group; and X − represents BF 4 − , PF 6 − , SbF 6 − or (C 6 H 5 ) 4 B − , and

(c) a basic compound that becomes less basic by irradiation with a radiation ray represented by one of the following formulae (I)-(III):

wherein, R 1 to R 3 and R 5 and R 6 each independently represents an alkyl, cycloalkyl, aralkyl, or aryl group that may be substituted; and R 4 represents an alkylene, cycloalkylene, or arylene group that may be substituted; Q − represents OH − , an aliphatic carboxylate anion, or an aromatic carboxylate anion; and any two of R 1 to R 3 in Formula (I), R 1 and R 3 in Formula (II), or R 5 and R 6 in Formula (III) may bond with each other to form a ring,

the ink composition further comprising an alicyclic epoxide;

wherein the ink composition comprises a cationically polymerizable component containing 40-55 wt % of the oxetane compound and 35-50 wt % of the alicyclic epoxide.

2. The ink composition of claim 1 , wherein the content of the basic compound (c) is 0.001 to 10 wt % based on the total solid content of the ink composition.

3. The ink composition of claim 1 , wherein the content of the compound (b) that generates acid by irradiation with a radiation ray is 0.1 to 20 wt % based on the total solid content of the ink composition.

4. The ink composition of claim 1 , wherein the content of the cationically polymerizable compound (a) is 10 to 95 wt % based on the total solid content of the ink composition.

5. The ink composition of claim 1 , further comprising a colorant (d).

6. The ink composition of claim 5 , wherein the colorant (d) is a pigment or oil soluble dye.

7. The ink composition of claim 1 , wherein the ink composition is for use in inkjet recording.

8. An inkjet recording method, comprising: printing on a recording medium with the ink composition of claim 1 by an inkjet printer, and hardening the printed ink composition by irradiation with a radiation ray.

9. A printed material formed by printing on a recording medium with the ink composition of claim 1 by an inkjet printer and then hardening the ink composition by irradiation with a radiation ray.

10. A method of producing a planographic printing plate, comprising: ejecting the ink composition of claim 1 onto a hydrophilic support, and hardening the ink composition by irradiation with a radiation ray, to thereby form a hydrophobic region thereon.

11. A planographic printing plate, comprising a hydrophobic region formed by ejecting the ink composition of claim 1 onto a hydrophilic support and hardening the ink by irradiation with a radiation ray.

12. The ink composition of claim 1 , wherein the cationically polymerizable oxetane compound is represented by formula (I).

13. The ink composition of claim 1 , wherein Q − in formula (I), (II), or (III) is OH − .

14. The ink composition of claim 1 , further comprising a sensitizer.

15. An ink composition comprising (a) a cationically polymerizable oxetane compound represented by one of the following formulae (1)-(5):

wherein R a1 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group, a furyl group or a thienyl group, provided that when there are two R a1 groups in the molecule, they may be the same as or different from each other;

R a2 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aromatic ring-containing group, an alkylcarbonyl group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, or an N-alkylcarbamoyl group having 2 to 6 carbon atoms;

R a3 represents a linear or branched alkylene group, a linear or branched poly(alkyleneoxy) group, a linear or branched unsaturated hydrocarbon group, a carbonyl group or a carbonyl group-containing alkylene group, a carboxyl group-containing alkylene group, a carbamoyl group-containing alkylene group, or one of the following groups:

wherein R a4 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a nitro group, a cyano group, a mercapto group, a lower alkylcarboxyl group, a carboxyl group, or a carbamoyl group;

R a5 represents an oxygen or sulfur atom, a methylene group, NH, SO, SO 2 , C(CF 3 ) 2 , or C(CH 3 ) 2 ;

R a6 represents an alkyl group having 1 to 4 carbon atoms or an aryl group;

n is an integer of 0 to 2,000;

R a7 represents an alkyl group having 1 to 4 carbon atoms, an aryl group, or a monovalent group having the following structure:

wherein R a8 represents an alkyl group having 1 to 4 carbon atoms or an aryl group;

m is an integer of 0 to 100;

R a9 represents a connecting group;

j is 3 or 4;

R a11 represents an alkyl group having 1 to 4 carbon atoms or a trialkylsilyl group; and

r is 1 to 4,

(b) a compound that generates an acid upon irradiation with a radiation ray represented by one of the following formulae (b1) and (b2):

wherein R 201 , R 202 and R 203 each independently represents an organic group, and any two of R 201 -R 203 may bind to each other to form a ring; R 204 and R 205 each independently represents an aryl group, an alkyl group or a cycloalkyl group; and X − represents BF 4 − , PF 6 − , SbF 6 − or (C 6 H 5 ) 4 B − , and

(c) a basic compound that becomes less basic by irradiation with a radiation ray represented by one of the following formulae (I)-(III):

wherein, R 1 to R 3 and R 5 and R 6 each independently represents an alkyl, cycloalkyl, aralkyl, or aryl group that may be substituted; and R 4 represents an alkylene, cycloalkylene, or arylene group that may be substituted; Q − represents OH − , an aliphatic carboxylate anion, or an aromatic carboxylate anion; and any two of R 1 to R 3 in Formula (I), R 1 and R 3 in Formula (II), or R 5 and R 6 in Formula (III) may bond with each other to form a ring, the ink composition further comprising an alicyclic epoxide;

wherein the ink composition comprises a cationically polymerizable component containing 35-40 wt % of the oxetane compound and 50-55 wt % of the alicyclic epoxide.

16. The ink composition of claim 15 , wherein the content of the basic compound (c) is 0.001 to 10 wt % based on the total solid content of the ink composition.

17. The ink composition of claim 15 , wherein the content of the compound (b) that generates acid by irradiation with a radiation ray is 0.1 to 20 wt % based on the total solid content of the ink composition.

18. The ink composition of claim 15 , wherein the content of the cationically polymerizable compound (a) is 10 to 95 wt % based on the total solid content of the ink composition.

19. The ink composition of claim 15 , further comprising a colorant (d).

20. The ink composition of claim 19 , wherein the colorant (d) is a pigment or oil soluble dye.

21. The ink composition of claim 15 , wherein the ink composition is for use in inkjet recording.

22. The ink composition of claim 15 , wherein the cationically polymerizable oxetane compound is represented by formula (I).

23. The ink composition of claim 15 , wherein Q − in formula (I), (II), or (III) is OH − .

24. The ink composition of claim 15 , further comprising a sensitizer.

25. An inkjet recording method, comprising: printing on a recording medium with the ink composition of claim 15 by an inkjet printer, and hardening the printed ink composition by irradiation with a radiation ray.

26. A printed material formed by printing on a recording medium with the ink composition of claim 15 by an inkjet printer and then hardening the ink composition by irradiation with a radiation ray.

27. A method of producing a planographic printing plate, comprising: ejecting the ink composition of claim 15 onto a hydrophilic support, and hardening the ink composition by irradiation with a radiation ray, to thereby form a hydrophobic region thereon.

28. A planographic printing plate, comprising a hydrophobic region formed by ejecting the ink composition of claim 15 onto a hydrophilic support and hardening the ink by irradiation with a radiation ray.