IMAGE FORMING METHOD, AND IMAGE FORMED MATTER

• US 20120128949A1
• Filed: 08/10/2010
• Published: 05/24/2012
• Est. Priority Date: 08/21/2009
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Goto, Hiroshi
• Granted Patent: US 8,814,340 B2
• Time in Patent Office: Days
• US Class Current: 428/207
• CPC Class Codes: B41J 2/2107 characterised by the ink properties supplying ink in a solid state B41J2/17593
• CPC Class Codes: B41M 5/0017 Application of ink-fixing material, e.g. mordant, precipitating agent, on the substrate prior to printing, e.g. by ink-jet printing, coating or spraying
• CPC Class Codes: B41M 7/0018 using ink-fixing material, e.g. mordant, precipitating agent, after printing, e.g. by ink-jet printing, coating or spraying
• CPC Class Codes: C09D 11/322 Pigment inks
• CPC Class Codes: C09D 11/38 characterised by non-macromolecular additives other than solvents, pigments or dyes
• CPC Class Codes: C09D 11/54 Inks based on two liquids, one liquid being the ink, the other liquid being a reaction solution, a fixer or a treatment solution for the ink
• CPC Class Codes: Y10T 428/24901 including coloring matter

Abstract

An image forming method including: applying a pre-treatment liquid onto a coating layer provided on at least one surface of a support of a recording medium, jetting an inkjet ink onto the coating layer, onto which the pre-treatment liquid has been applied, so as to form an image, and applying or jetting a post-treatment liquid onto the coating layer, onto which the inkjet ink has been jetted, so as to form a transparent protective layer on the coating layer, wherein the inkjet ink contains the water-dispersible colorant, a water-soluble organic solvent, a surfactant, a penetrant and water, and wherein an amount of pure water transferred into the recording medium, provided with the coating layer, measured at a contact time of 100 ms with a dynamic scanning liquid absorptometer is 1 ml/m² to 10 ml/m², and the pre-treatment liquid contains a water-soluble aliphatic organic acid.

Claims

1. An image forming method, comprising:

applying a pre-treatment liquid, capable of aggregating a water-dispersible colorant, onto a surface of a coating layer on a surface of a support of a recording medium,

jetting an inkjet ink onto the surface of the coating layer, onto which the pre-treatment liquid has been applied, thereby forming an image, and

applying or jetting a post-treatment liquid onto the surface of the coating layer, onto which the inkjet ink has been jetted, thereby forming a transparent protective layer on the coating layer,

wherein the inkjet ink comprises the water-dispersible colorant, a water-soluble organic solvent, a surfactant, a penetrant, and water,

an amount of pure water transferred into the coating layer on the surface of the recording medium is from 1 mL/m² to 10 mL/m² measured at a contact time of 100 ms with a dynamic scanning liquid absorptometer, and

the pre-treatment liquid comprises a water-soluble aliphatic organic acid.

2. The image forming method of claim 1, wherein a number of carbon atoms of the water-soluble aliphatic organic acid is from 2 to 6.

3. The image forming method of claim 1,

wherein the water-soluble aliphatic organic acid comprises at least one compound of a formula selected from the group consisting of Formulae (I), (II), and (III):

4. The image forming method of claim 1, wherein the pre-treatment liquid further comprises a water-soluble organic monoamine compound.

5. The image forming method of claim 4, wherein the water-soluble organic monoamine compound comprises at least one compound of a formula selected from the group consisting of Formulae (IV) and (V):

6. The image forming method of claim 1, wherein a static surface tension of the pre-treatment liquid is 30 mN/m or lower.

7. The image forming method of claim 1, wherein the water-dispersible colorant is a pigment, and the pigment comprises an anionic self-dispersible pigment, a pigment coated with an anionic resin, or both.

8. The image forming method of claim 1, wherein a static surface tension of the inkjet ink is 30 mN/m or lower.

9. The image forming method of claim 1, wherein the post-treatment liquid comprises a thermoplastic resin.

10. The image forming method of claim 9, wherein the thermoplastic resin is a water-dispersible resin, with a glass transition temperature (Tg) of −

30°

C. or higher and a minimum film forming temperature (MFT) of 50°

C. or lower.

11. The image forming method of claim 10, wherein the water-dispersible resin is at least one resin selected from the group consisting of an acrylic resin, a styrene-acrylic resin, a urethane resin, an acryl-silicone resin, and a fluorine resin.

12. The image forming method of claim 1, wherein a dry adhesion amount of the post-treatment liquid to the recording medium is from 0.5 g/m² to 10 g/m².

13. The image forming method of claim 1, further comprising:

heating the recording medium, onto which the post-treatment liquid has been applied or jetted, at 100°

C. to 150°

C. by a heating unit, thereby thermally fixing the inkjet ink on the recording medium.

15. The image forming method of claim 1, wherein a wet coating amount of the pre-treatment liquid applied to the surface of the coating layer is from 0.1 g/m² to 30.0 g/m².

16. The image forming method of claim 15, wherein the wet coating amount of the pre-treatment liquid applied to the surface of the coating layer is from 0.2 g/m² to 10.0 g/m².

17. The image forming method of claim 1, wherein the water-soluble aliphatic acid comprises an organic acid comprising a sulfo group.

18. The image forming method of claim 17, wherein the water-soluble aliphatic acid comprises taurine.

19. The image forming method of claim 1, wherein the water-soluble organic solvent comprises a polyhydric alcohol, a polyhydric alcohol alkyl ether, a polyhydric alcohol aryl ether, a nitrogen-containing heterocyclic compound, an amide, an amine, a sulfur-containing compound, propylene carbonate, ethylene carbonate, or a mixture thereof.

20. The image forming method of claim 1, wherein an equilibrium water content of the water-soluble organic solvent is 30% by mass or more at 23°

C. and 80% relative humidity.

14. An image formed matter obtained by an image forming method, comprising:

applying a pre-treatment liquid, capable of aggregating a water-dispersible colorant, onto a surface of a coating layer on a surface of a support of a recording medium,

jetting an inkjet ink onto the surface of the coating layer, onto which the pre-treatment liquid has been applied, thereby forming an image, and

applying or jetting a post-treatment liquid onto the surface of the coating layer, onto which the inkjet ink has been jetted, thereby forming a transparent protective layer on the coating layer,

wherein the inkjet ink comprises the water-dispersible colorant, a water-soluble organic solvent, a surfactant, a penetrant, and water,

an amount of pure water transferred into the coating layer on the surface of the recording medium is from 1 mL/m² to 10 mL/m² measured at a contact time of 100 ms with a dynamic scanning liquid absorptometer, and

the pre-treatment liquid comprises a water-soluble aliphatic organic acid.