Overcoating liquid, ink set, image forming method, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9783700-B2
Application number	US-201514633328-A
Country	US
Kind code	B2
Filing date	Feb 27, 2015
Priority date	Mar 11, 2014
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

An overcoating liquid contains a hydrodispersible polyurethane; a compound represented by Chemical formula 1: C 6 F 13 —CH 2 CH 2 O(CH 2 CH 2 O) n H, where n represents an integer of from 1 to 40; a compound represented by Chemical formula 2: HOR 1 R 3 C—(CH 2 ) n —CR 2 R 4 OH, where R 1 and R 2 each, independently represent alkyl groups having three to six carbon atoms, R 3 and R 4 each, independently represent methyl groups or ethyl groups, and n represents an integer of from 1 to 6; and water, wherein the overcoating liquid is applied to the surface of a recording medium onto which inkjet ink is already discharged.

First claim

What is claimed is:

1. An overcoating liquid comprising:
a hydrodispersible polyurethane that includes at least one of polyacrylate-urethane and polycarbonate-urethane;
a compound represented by Chemical formula 1: C 6 F 13 —CH 2 CH 2 O(CH 2 CH 2 O) n H, where n represents an integer of from 1 to 40;
a compound represented by Chemical formula 2: HOR 1 R 3 C—(CH 2 ) n —CR 2 R 4 OH, where R 1 and R 2 each, independently represent alkyl groups having three to six carbon atoms, R 3 and R 4 each, independently represent methyl groups or ethyl groups, and n represents an integer of from 1 to 6; and
water,
wherein the overcoating liquid is applied to a surface of a recording medium on which inkjet ink is already discharged.

2. The overcoating liquid according to claim 1 , wherein the compound represented by Chemical formula 1 accounts for 0.05% by weight to 1% by weight.

3. The overcoating liquid according to claim 1 , wherein the compound represented by Chemical formula 2 is 2,4,7,9-tetramethyl-4,7-decane diol.

4. The overcoating liquid according to claim 1 , wherein the compound represented by Chemical formula 2 accounts for 0.2% by weight to 1% by weight.

5. The overcoating liquid according to claim 1 , further comprising polyethylene wax.

6. The overcoating liquid according to claim 5 , wherein a mass ratio of the polyethylene wax to the hydrodispersible polyurethane ranges from 0.1 to 1.

7. An inkset comprising:
an inkjet ink comprising:
a hydrodispersible colorant,
a surfactant,
a hydrosoluble organic solvent, and
water; and

an overcoating liquid comprising:
a hydrodispersible polyurethane that includes at least one of polyacrylate-urethane and polycarbonate-urethane;
a compound represented by Chemical formula 1: C 6 F 13 —CH 2 CH 2 O(CH 2 CH 2 O) n H, where n represents an integer of from 1 to 40;
a compound represented by Chemical formula 2: HOR 1 R 3 C—(CH 2 ) n —CR 2 R 4 OH, where R 1 and R 2 each, independently represent alkyl groups having three to six carbon atoms, R 3 and R 4 each, independently represent methyl groups or ethyl groups, and n represents an integer of from 1 to 6; and

water,
wherein the overcoating liquid is applied to a surface of a recording medium on which the inkjet ink is already discharged.

8. An image forming method comprising:
discharging inkjet ink to a recording medium comprising a substrate; and
applying the overcoating liquid of claim 1 to a surface of the recording medium on which the inkjet ink is already discharged,
wherein the inkjet ink comprises a hydrodispersible colorant, a wetting agent, a surfactant, a permeating agent, and water.

9. The image forming method according to claim 8 , further comprising heat-fixing the overcoating liquid on the recording medium.

10. The image forming method according to claim 8 , wherein a coated layer is formed on one or both sides of the substrate and a transfer amount of pure water ranges from 1 mL/m 2 to 10 mL/m 2 when a contact time of a surface on which the coated layer is formed is 100 ms.

11. An image forming apparatus comprising:
a discharging device to discharge inkjet ink to a recording medium;
the overcoating liquid of claim 1 ;
an application device to apply the overcoating liquid to a surface of the recording medium on which the inkjet ink is already discharged,
wherein the inkjet ink comprises a hydrodispersible colorant, a wetting agent, a surfactant, a permeating agent, and water.

Assignees

• Tamai Takashi
• Namba Michihiko
• Gotoh Akihiko
• Ricoh Co Ltd

Inventors

• Tamai Takashi
• Namba Michihiko
• Gotoh Akihiko

Classifications

• C09D11/322

  Pigment inks · CPC title

• C09D175/04 Primary

  Polyurethanes · CPC title

• B41M7/0018

  using ink-fixing material, e.g. mordant, precipitating agent, after printing, e.g. by ink-jet printing, coating or spraying · CPC title

• C09D11/40

  Ink-sets specially adapted for multi-colour inkjet printing · CPC title

• B41M7/0036

  using protective coatings or layers dried without curing · CPC title