Cleaning liquid for aqueous ink

Patent metadata

Field	Value
Publication number	US-10981385-B2
Application number	US-201716473398-A
Country	US
Kind code	B2
Filing date	Dec 26, 2017
Priority date	Dec 28, 2016
Publication date	Apr 20, 2021
Grant date	Apr 20, 2021

Abstract

The present invention relates to a cleaning liquid for a water-based ink that contains a pigment and a water-insoluble polymer, said cleaning liquid containing (A) a surfactant, (B) a water-soluble organic solvent containing (b-1) diethylene glycol monoisopropyl ether, and water, in which the surfactant (A) contains at least one compound selected from the group consisting of (a-1) an acetylene glycol or an ethyleneoxide adduct of the acetylene glycol, and (a-2) a polyethylene glycol alkyl ether containing an alkyl group having not less than 8 carbon atoms or a polyethylene glycol aryl ether containing an aryl group having not less than 6 carbon atoms, and a content of the water-soluble organic solvent (B) in the cleaning liquid is from 5 to 30% by mass; and a method of cleaning a water-based ink using the cleaning liquid.

First claim

The invention claimed is:

1. A cleaning liquid for a water-based ink that comprises a pigment and a water-insoluble polymer, said cleaning liquid comprising (A) a surfactant, (B) a water-soluble organic solvent comprising (b-1) diethylene glycol monoisopropyl ether, and water, in which
the surfactant (A) comprises at least one compound selected from the group consisting of (a-1) an acetylene glycol or an ethyleneoxide adduct of the acetylene glycol, and (a-2) a polyethylene glycol alkyl ether comprising an alkyl group having not less than 8 carbon atoms or a polyethylene glycol aryl ether comprising an aryl group having not less than 6 carbon atoms,
the water-soluble organic solvent (B) further comprises (b-2) a compound having a solubility parameter (SP value) of not less than 20 (MPa) 1/2 and not more than 35 (MPa) 1/2 , the compound (b-2) is a polyhydric alcohol, and a mass ratio of the compound (b-2) to the diethylene glycol monoisopropyl ether (b-1) [(b-2)/(b-1)] is not less than 0.03 and not more than 3, and
a content of the water-soluble organic solvent (B) in the cleaning liquid is not less than 7% by mass and not more than 30% by mass, and
a content of the diethylene glycol monoisopropyl ether (b-1) in the cleaning liquid is not less than 5% by mass and not more than 25% by mass.

2. The cleaning liquid according to claim 1 , wherein an average molar number of addition of ethyleneoxide of the acetylene glycol or the ethyleneoxide adduct of the acetylene glycol (a-1) is not less than 0 mol and not more than 35 mol.

3. The cleaning liquid according to claim 1 , wherein the polyethylene glycol alkyl ether comprising an alkyl group having not less than 8 carbon atoms or the polyethylene glycol aryl ether comprising an aryl group having not less than 6 carbon atoms (a-2) is represented by the following formula (1):
R 1 O−(EO) n −H  (1)

wherein R 1 is an alkyl group having not less than 8 carbon atoms or an aryl group having not less than 6 carbon atoms; EO is a group derived from ethyleneoxide; and n is an average molar number of addition of EO.

4. The cleaning liquid according to claim 3 , wherein the average molar number n of addition of EO in the formula (1) is not less than 4 and not more than 30.

5. The cleaning liquid according to claim 1 , wherein the acetylene glycol or the ethyleneoxide adduct of the acetylene glycol (a-1) is used in combination with the polyethylene glycol alkyl ether comprising an alkyl group having not less than 8 carbon atoms or the polyethylene glycol aryl ether comprising an aryl group having not less than 6 carbon atoms (a-2).

6. The cleaning liquid according to claim 5 , wherein a mass ratio of the component (a-1) to the component (a-2) [(a-1)/(a-2)] is not less than 0.1 and not more than 2.

7. The cleaning liquid according to claim 1 , wherein a mass ratio of the surfactant (A) to the diethylene glycol monoisopropyl ether (b-1) [(A)/(b-1)] is not less than 0.01 and not more than 2.

8. A method of cleaning a water-based ink, comprising the step of allowing the water-based ink that comprises a pigment and a water-insoluble polymer to come into contact with the cleaning liquid according to claim 1 .

9. The method of cleaning a water-based ink according to claim 8 , wherein the water-based ink is used for gravure printing or ink-jet printing.

10. The method of cleaning a water-based ink according to claim 8 , wherein the water-insoluble polymer is an acrylic polymer.

11. The cleaning liquid according to claim 1 , wherein a content of the compound (b-2) in the cleaning liquid is not less than 1% by mass and not more than 15% by mass.

12. The cleaning liquid according to claim 1 , wherein a total content of diethylene glycol monoisopropyl ether (b-1) and the compound (b-2) in the water-soluble organic solvent (B) is not less than 80% by mass.

13. The cleaning liquid according to claim 1 , wherein the compound (b-2) is at least one compound selected from the group consisting of propylene glycol and glycerin.

14. The cleaning liquid according to claim 1 , wherein a boiling point of the water-soluble organic solvent (B) is not lower than 150° C. and not higher than 260° C.

15. The cleaning liquid according to claim 1 , wherein a total content of the acetylene glycol or the ethyleneoxide adduct of the acetylene glycol (a-1) and the polyethylene glycol alkyl ether containing an alkyl group having not less than 8 carbon atoms or the polyethylene glycol aryl ether containing an aryl group having not less than 6 carbon atoms (a-2) in the surfactant (A) is not less than 80% by mass.

16. The cleaning liquid according to claim 1 , wherein a content of the acetylene glycol or the ethyleneoxide adduct of the acetylene glycol (a-1) in the cleaning liquid is not less than 0.01% by mass and not more than 5% by mass.

17. The cleaning liquid according to claim 1 , wherein a content of the polyethylene glycol alkyl ether containing an alkyl group having not less than 8 carbon atoms or the polyethylene glycol aryl ether containing an aryl group having not less than 6 carbon atoms (a-2) in the cleaning liquid is not less than 0.01% by mass and not more than 5% by mass.

18. The cleaning liquid according to claim 1 , wherein a content of the surfactant (A) in the cleaning liquid is preferably not less than 0.3% by mass and not more than 10% by mass.

Assignees

• Kao Corp

Inventors

• Suzuki Takayuki
• Takeno Hirotaka

Classifications

• C11D3/43

  Solvents · CPC title

• C11D17/0008 Primary

  aqueous liquid non soap compositions (C11D3/0015, C11D3/3947, C11D3/3956 take precedence) · CPC title

• C11D3/2065

  Polyhydric alcohols · CPC title

• C11D1/72

  Ethers of polyoxyalkylene glycols · CPC title

• B41J2/16552

  using cleaning fluids · CPC title