Method for producing printed item

Patent metadata

Field	Value
Publication number	US-10808137-B2
Application number	US-201816141003-A
Country	US
Kind code	B2
Filing date	Sep 25, 2018
Priority date	Sep 29, 2017
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

A method for producing a printed item including discharging two or more inks by an inkjet method toward a recording medium to form an image is disclosed, wherein the two or more inks include a first oil-based inkjet ink containing a first colorant and a non-aqueous solvent and having an ink surface tension of less than 27.0 mN/m, and a second oil-based inkjet ink containing a second colorant and a non-aqueous solvent and having an ink surface tension of 27.0 mN/m or greater, and the method includes discharging the first oil-based inkjet ink toward the recording medium at a discharge volume of at least 20 pl per one liquid droplet to form dots with the first oil-based inkjet ink, and subsequently discharging the second oil-based inkjet ink toward the recording medium at a discharge volume of less than 20 pl per one liquid droplet so as to overlap with the dots formed with the first oil-based inkjet ink.

First claim

What is claimed is:

1. A method for producing a printed item comprising discharging two or more inks by an inkjet method toward a recording medium to form an image, wherein
the two or more inks comprise:
a first oil-based inkjet ink comprising a first colorant and a non-aqueous solvent, and having an ink surface tension of less than 27.0 mN/m at 23° C., and
a second oil-based inkjet ink comprising a second colorant and a non-aqueous solvent, and having an ink surface tension of 27.0 mN/m at 23° C. or greater, and
the method comprises:
discharging the first oil-based inkjet ink toward the recording medium at a discharge volume of at least 20 pl per one liquid droplet to form dots with the first oil-based inkjet ink, and subsequently discharging the second oil-based inkjet ink toward the recording medium at a discharge volume of less than 20 pl per one liquid droplet so as to overlap with the dots formed with the first oil-based inkjet ink.

2. The method for producing a printed item according to claim 1 , wherein a surface tension of the first oil-based inkjet ink is at least 22.0 mN/m but not more than 26.0 mN/m at 23° C.

3. The method for producing a printed item according to claim 1 , wherein a total of the discharge volume per one liquid droplet of the first oil-based inkjet ink and the discharge volume per one liquid droplet of the second oil-based inkjet ink is not more than 60 pl.

4. The method for producing a printed item according to claim 1 , wherein the non-aqueous solvent of the first oil-based inkjet ink comprises at least 15% by mass of a silicone oil relative to a total mass of the non-aqueous solvent.

5. The method for producing a printed item according to claim 1 , wherein the non-aqueous solvent of the second oil-based inkjet ink comprises at least 15% by mass of at least one selected from the group consisting of a fatty acid ester-based solvent, a higher alcohol-based solvent, a petroleum-based hydrocarbon solvent, a higher fatty acid-based solvent and a glycol ether-based solvent, relative to a total mass of the non-aqueous solvent.

6. The method for producing a printed item according to claim 1 , wherein
the first oil-based inkjet ink is a black ink, and
the second oil-based inkjet ink is a cyan ink, a yellow ink, or a magenta ink.

Assignees

• Riso Kagaku Corp

Inventors

• Ando Kazuyuki
• Shimura Shinichiro
• Morinaga Marie
• Sugiura Hikaru
• Ozawa Shinsuke

Classifications

• C09D11/06

  based on fatty oils · CPC title

• C09D11/324

  containing carbon black · CPC title

• C09D11/033

  characterised by the solvent · CPC title

• C09D11/40 Primary

  Ink-sets specially adapted for multi-colour inkjet printing · CPC title

• C09D11/037

  characterised by the pigment · CPC title