# US 2014/0198151 A1 · Ink, ink cartridge and ink jet recording method

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- Number: US 2014/0198151 A1
- Document ID: US20140198151A1
- Status: Published application
- Kind: A1
- Application number: 14/232,650
- Filed: 2013-02-27
- Published: 2014-07-17
- Earliest claimed: 2012-03-02
- Assignees: Canon Kabushiki Kaisha
- Applicants: Canon Kabushiki Kaisha
- Inventors: Masashi Yamamoto; Eiichi Nakata; Shuichi Okazaki; Satoshi Takebayashi
- Web page: https://patentgrep.com/patent/US20140198151A1

## CPC

- 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)

## Abstract

An ink containing water, a water-soluble organic solvent and an organic pigment, wherein a primary particle of the organic pigment has a ratio (minor axis b)/(major axis a) of 0.70 or more and a particle diameter of 35 nm or less, the ink contains a water-soluble organic solvent with a dielectric constant of 25.0 or less in an amount of 0.5% by mass or more based on the total mass of the ink, and a dielectric constant ∈mix of the ink as calculated according to the following equation (1) is 66-72: ∈mix=Σn∈nrn/Σnrn Equation (1): wherein n means a kind of water or the water-soluble organic solvent, ∈n is a dielectric constant of water or the water-soluble organic solvent represented by n, and rn is a content of water or the water-soluble organic solvent represented by n based on the total mass of the ink.

## Claims

### Claim 1

An ink comprising water, a water-soluble organic solvent and an organic pigment, wherein
a primary particle of the organic pigment has a ratio (minor axis b)/(major axis a) of 0.70 or more and a particle diameter of 35 nm or less,
the ink contains a water-soluble organic solvent with a dielectric constant of 25.0 or less in an amount of 0.5% by mass or more based on the total mass of the ink, and
a dielectric constant ∈mix of the ink as calculated according to the following equation (1) is 66 or more and 72 or less:
∈mix=Σn∈nrn/Σnrn
wherein n means a kind of water or the water-soluble organic solvent, ∈n is a dielectric constant of water or the water-soluble organic solvent represented by n, and rn is a content of water or the water-soluble organic solvent represented by n based on the total mass of the ink.

### Claim 2 (depends on 1)

The ink according to claim 1, wherein the organic pigment comprises a self-dispersible pigment.

### Claim 3 (depends on 1)

The ink according to claim 1, wherein the organic pigment comprises at least one selected from the group consisting of a phthalocyanine pigment, a quinacridone pigment and an azo pigment.

### Claim 4 (depends on 1)

The ink according to claim 1, wherein the organic pigment comprises a phthalocyanine pigment.

### Claim 5 (depends on 1)

The ink according to claim 1, further comprising a polyoxyethylene alkyl ether as a surfactant.

### Claim 6 (depends on 5)

The ink according to claim 5, wherein the content (% by mass) of the surfactant is 0.05% by mass or more and 2.0% by mass or less based on the total mass of the ink.

### Claim 7 (depends on 1)

The ink according to claim 1, wherein a 1,2-alkanediol is contained in the water-soluble organic solvent with a dielectric constant of 25.0 or less, and
the content (% by mass) of the 1,2-alkanediol is 0.2% by mass or more and 10.0% by mass or less based on the total mass of the ink.

### Claim 8 (depends on 1)

The ink according to claim 1, which is an ink jet ink.

### Claim 9 (depends on 1)

An ink cartridge comprising an ink and an ink storage portion storing the ink, wherein
the ink comprises the ink according to claim 1.

### Claim 10 (depends on 1)

An ink jet recording method comprising ejecting an ink from a recording head of an ink jet system to record an image on a recording medium, wherein the ink comprises the ink according to claim 1.