# US 9,751,325 B2 · Inkjet printing method and inkjet printer used in the printing method

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- Number: US 9,751,325 B2
- Document ID: US9751325B2
- Status: Granted
- Kind: B2
- Application number: 14/576,397
- Filed: 2014-12-19
- Published: 2015-07-02
- Granted: 2017-09-05
- Earliest claimed: 2013-12-27
- Assignees: Riso Kagaku Corporation
- Applicants: Riso Kagaku Corporation
- Inventors: Kenji Shimomura; Hiroshi Hayashi
- Web page: https://patentgrep.com/patent/US9751325B2

## CPC

- B41J 2/2107: {characterised by the ink properties (supplying ink in a solid state B41J2/17593)}
- B41J 2/2146: {for line print heads}
- B41M 5/0011: {Pre-treatment or treatment during printing of the recording material, e.g. heating, irradiating (after-treatment of prints B41M7/00; printers for treating or overcoating copy materials before, during or after printing B41J11/0015)}
- C09D 11/322: Pigment inks
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41M: PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING, (correction of typographical errors B41J; processes for applying transfer pictures or the like B44C1/16; fluid media for correction of typographical errors by coating C09D10/00; printing textiles D06P)
- 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

Using a plurality of colors of inks comprising an oil-based ink containing a dye lake pigment and an oil-based ink containing a pigment other than dye lake pigments, and superposing the plurality of colors of inks when printing, the oil-based ink containing a dye lake pigment is ejected on a printing medium prior to the oil-based ink containing a pigment other than dye lake pigments.

## Claims

### Claim 1

An inkjet printing method comprising:
ejecting an oil-based ink (A) containing a dye lake pigment onto a printing medium;
ejecting an oil-based ink (B) containing a pigment other than dye lake pigments onto the printing medium, and
ejecting an oil-based ink (B′) containing a pigment other than dye lake pigments onto the printing medium,
wherein the oil-based ink (A) is ejected onto the printing medium prior to the oil-based ink (B), so that the oil-based ink (B) is disposed on the oil-based ink (A) on the printing medium, and
wherein the color of the oil-based ink (B) is different from the color of the oil-based ink (B′).

### Claim 2 (depends on 1)

The inkjet printing method according to claim 1, wherein the oil-based ink (A) is ejected onto the printing medium prior to the oil-based ink (B) and the oil-based ink (B′).

### Claim 3 (depends on 2)

The inkjet printing method according to claim 2, wherein the ejection interval between ejection of the oil-based ink (A) and ejection of the oil-based ink (B) is larger than the ejection interval between ejection of the oil-based ink (B) and ejection of the oil-based ink (B′).

### Claim 4 (depends on 1)

The inkjet printing method according to claim 1, wherein the dye lake pigment is a pigment obtained by laking a xanthene derivative dye.

### Claim 5 (depends on 1)

The inkjet printing method according to claim 1, wherein the dye lake pigment is a pigment obtained by laking a triphenylmethane derivative dye.

### Claim 6

An inkjet printer comprising:
an inkjet head (a) holding an oil-based ink (A) containing a dye lake pigment,
an inkjet head (b) holding an oil-based ink (B) containing a pigment other than dye lake pigments, and
an inkjet head (b′) holding an oil-based ink (B′) containing a pigment other than dye lake pigments,
a carrying part of carrying the printing medium positioned to face the inkjet head, wherein
the inkjet head (a) is positioned upstream of the inkjet head (b) in a direction of carrying the printing medium, and
the color of oil-based ink (B) is different from the color of oil-based ink (B′).

### Claim 7 (depends on 6)

The inkjet printer according to claim 6, wherein, among the inkjet head (a), the inkjet head (b), and the inkjet head (b′), inkjet head (a) is positioned in the uppermost stream in the carrying direction of the printing medium.

### Claim 8 (depends on 7)

The inkjet printer according to claim 7, wherein the printer is structured and configured to provide an ejection interval between the oil-based ink (A) and the oil-based ink (B) is larger than the ejection interval between the oil-based ink (B) and the oil-based ink (B′).

### Claim 9 (depends on 6)

The inkjet printer according to claim 6, wherein the dye lake pigment is a pigment obtained by laking a xanthene derivative dye.

### Claim 10 (depends on 6)

The inkjet printer according to claim 6, wherein the dye lake pigment is a pigment obtained by laking a triphenylmethane derivative dye.