# US 8,783,843 B2 · Set of ink and reaction liquid, and image forming method

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- Number: US 8,783,843 B2
- Document ID: US8783843B2
- Status: Granted
- Kind: B2
- Application number: 13/440,342
- Filed: 2012-04-05
- Published: 2012-10-25
- Granted: 2014-07-22
- Earliest claimed: 2011-04-19
- Assignees: Canon Kabushiki Kaisha
- Applicants: Kenji Moribe; Yasuhito Mori
- Inventors: Kenji Moribe; Yasuhito Mori
- Web page: https://patentgrep.com/patent/US8783843B2

## CPC

- 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
- B41J 2/01: Ink jet
- B41J 2/2107: {characterised by the ink properties (supplying ink in a solid state B41J2/17593)}
- C09D 11/322: Pigment inks
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

A set of an ink containing a pigment dispersed by a water-soluble resin and having the surface tension of 38 mN/m or less and a reaction liquid containing a polyvalent metal ion and a surfactant, which is an ethylene oxide adduct of a higher alcohol of a linear primary or secondary alcohol or an isoalkyl alcohol, and has a HLB value of 13.0 or more as determined by the Griffin method. The content of the polyvalent metal ion in the reaction liquid is 10.0 times or more in terms of molar ratio as much as an amount of an acidic group derived from the water-soluble resin in the ink and the content of the surfactant in the reaction liquid is 0.15 times or more in terms of mass ratio as much as the total content of the pigment and water-soluble resin in the ink.

## Claims

### Claim 1

A set of an ink and a reaction liquid for ink jet, the set having a combination of an ink comprising a pigment dispersed by a water-soluble resin, and a reaction liquid containing no coloring material but comprising a polyvalent metal ion and a surfactant, wherein
a surface tension of the ink is 38 mN/m or less,
a content (μmol/g) of the polyvalent metal ion in the reaction liquid is 10.0 times or more in terms of molar ratio as much as an amount (μmol/g) of an acidic group derived from the water-soluble resin in the ink,
the surfactant in the reaction liquid comprises an ethylene oxide adduct of a higher alcohol selected from the group consisting of a linear primary alcohol, a linear secondary alcohol and an isoalkyl alcohol, and has a HLB value of 13.0 or more as determined by the Griffin method, and
a content (% by mass) of the surfactant in the reaction liquid is 0.15 times or more in terms of mass ratio as much as the total content (% by mass) of the pigment and the water-soluble resin in the ink.

### Claim 2 (depends on 1)

The set according to claim 1, wherein the polyvalent metal ion is at least one selected from the group consisting of Ca2+, Al3+ and Y3+.

### Claim 3 (depends on 1)

The set according to claim 1, wherein a number of carbon atoms of the higher alcohol is 16 or more.

### Claim 4 (depends on 1)

An image forming method in which an ink and a reaction liquid are respectively ejected from a recording head of an ink jet system to bring the ink and the reaction liquid into contact with each other on a recording medium, thereby forming an image, wherein the set of the ink and the reaction liquid according to claim 1 is used as the ink and the reaction liquid.

### Claim 5 (depends on 1)

The set according to claim 1, wherein a content (% by mass) of the water-soluble resin in the ink is 0.1% by mass or more and 3.0% by mass or less based on the total mass of the ink.

### Claim 6 (depends on 1)

The set according to claim 1, wherein a content (% by mass) of the pigment in the ink is 0.1% by mass or more and 15.0% by mass or less based on the total mass of the ink.

### Claim 7 (depends on 1)

The set according to claim 1, wherein a content (% by mass) of the surfactant in the reaction liquid is 0.10% by mass or more and 2.5% by mass or less based on the total mass of the reaction liquid.

### Claim 8 (depends on 1)

The set according to claim 1, wherein a content (% by mass) of the polyvalent metal ion as a form of a polyvalent metal salt in the reaction liquid is 3.0% by mass or more and 20.0% by mass or less based on the total mass of the reaction liquid.

### Claim 9 (depends on 1)

The set according to claim 1, wherein an acid value of the water-soluble resin is 80 mg KOH/g or more and 300 mg KOH/g or less.