# US 2014/0192112 A1 · Image forming method and image forming apparatus

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- Number: US 2014/0192112 A1
- Document ID: US20140192112A1
- Status: Published application
- Kind: A1
- Application number: 14/074,044
- Filed: 2013-11-07
- Published: 2014-07-10
- Earliest claimed: 2013-01-07
- Assignees: Ricoh Company, Ltd.
- Inventors: Hidefumi NAGASHIMA; Michihiko Namba; Kiyofumi Nagai
- Web page: https://patentgrep.com/patent/US20140192112A1

## CPC

- B41M 7/00: After-treatment of prints, e.g. heating, irradiating, {setting of the ink, protection of the printed stock (pre-treatment or treatment during printing B41M5/0011; printers for treating or overcoating copy materials before, during or after printing B41J11/0015)}
- B41J 2/01: Ink jet
- B41M 5/0017: {Application of ink-fixing material, e.g. mordant, precipitating agent, on the substrate prior to printing, e.g. by ink-jet printing, coating or spraying}
- B41M 7/0018: {using ink-fixing material, e.g. mordant, precipitating agent, after printing, e.g. by ink-jet printing, coating or spraying}
- B41M 7/0027: {using protective coatings or layers by lamination or by fusion of the coatings or layers}
- B41M 7/0036: {using protective coatings or layers dried without curing}
- B41M 7/02: Dusting {, e.g. with an anti-offset powder for obtaining raised printing such as by thermogravure (B41M7/0027, B41M7/0036, B41M7/0045, B41M7/0054, B41M7/0072, B41M7/0081, B41M7/009 take precedence); Varnishing (devices for treating the surfaces of sheets, webs, or other articles in connection with printing B41F23/00, B41L23/00)}
- 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)
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

An image forming method includes discharging an inkjet ink including a water-dispersible colorant, a wetter, a surfactant, a penetrant water-dispersible polyurethane resin having a median diameter of from 0.01 to 0.10 μm water and at least one of a polyethylene wax and a paraffin wax on the surface of the recording medium on which the inkjet ink is discharged.

## Claims

### Claim 1

An image forming method, comprising:
discharging an inkjet ink comprising a water-dispersible colorant, a wetter, a surfactant, a penetrant and water on a surface of a recording medium; and
applying an after-treatment liquid comprising a water-dispersible polyurethane resin having a median diameter of from 0.01 to 0.10 μm, water and at least one of a polyethylene wax and a paraffin wax on the surface of the recording medium on which the inkjet ink is discharged.

### Claim 2 (depends on 1)

The image forming method of claim 1, wherein the water-dispersible polyurethane resin is an acryl-modified polyurethane resin or a carbonate-modified polyurethane resin.

### Claim 3 (depends on 1)

The image forming method of claim 1, wherein the after-treatment liquid comprises the polyethylene wax such that a weight ratio of the water-dispersible polyurethane resin to the polyethylene wax is from 1 to 10.

### Claim 4 (depends on 1)

The image forming method of claim 1, wherein the after-treatment liquid comprises the polyethylene wax and the paraffin wax such that a weight ratio of the paraffin wax to the polyethylene wax is from 1 to 9.

### Claim 5 (depends on 1)

The image forming method of claim 1, wherein the after-treatment liquid further comprises polyether-modified polydimethylsiloxane.

### Claim 6 (depends on 1)

The image forming method of claim 1, further comprising:
applying a pre-treatment liquid comprising amine on the surface of the recording medium; and
discharging the inkjet ink on the surface thereof on which the pre-treatment liquid is applied.

### Claim 7 (depends on 6)

The image forming method of claim 6, wherein the pre-treatment liquid further comprises the water-dispersible polyurethane resin having a median diameter of from 0.01 to 0.10 μm, and at least one of the polyethylene wax and the paraffin wax.

### Claim 8 (depends on 6)

The image forming method of claim 6, wherein the pre-treatment liquid further comprises polyether-modified polydimethylsiloxane.

### Claim 9 (depends on 1)

The image forming method of claim 1, wherein the recording medium comprises:
a substrate; and
a coated layer formed on one side or both sides of the substrate,
wherein pure water transfers to the recording medium in an amount of form 1 to 10 mL/m2 when contacting the surface thereof on which the coated layer is formed for 100 ms.

### Claim 10

An image forming apparatus, comprising:
a discharger configured to discharge an inkjet ink comprising a water-dispersible colorant, a wetter, a surfactant, a penetrant and water on a surface of a recording medium; and
an applicator configured to apply an after-treatment liquid comprising a water-dispersible polyurethane resin having a median diameter of from 0.01 to 0.10 μm, water and at least one of a polyethylene wax and a paraffin wax on the surface of the recording medium on which the inkjet ink is discharged.