Method for manufacturing printed material using lithographic printing ink, and lithographic printing ink set

Patent metadata

Field	Value
Publication number	US-11434384-B2
Application number	US-201716332551-A
Country	US
Kind code	B2
Filing date	Sep 25, 2017
Priority date	Sep 30, 2016
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

To provide is a manufacturing method for obtaining printed material in which, in lithographic printing, a printed part where multiple colors are superimposed on each other has a high gloss, and also a lithographic printing ink set. The method for manufacturing printed material according to the present invention includes a step of coating at least black ink for lithographic printing, cyan ink for lithographic printing, magenta ink for lithographic printing, and yellow ink for lithographic printing on a substrate, in which a difference in surface tension between the inks to be coated on a substrate is at most equal to 3.5 mN/m. The lithographic printing ink set according to the present invention is a lithographic printing ink set including at least black ink, cyan ink, magenta ink, and yellow ink, in which a difference in surface tension between the inks included in the lithographic printing ink set is at most equal to 3.5 mN/m.

First claim

The invention claimed is:

1. A method for manufacturing printed material comprising a step of coating on a substrate with a lithographic printing process: at least black ink for lithographic printing, cyan ink for lithographic printing, magenta ink for lithographic printing, and yellow ink for lithographic printing, wherein
a difference in surface tension between the inks to be coated on the substrate is at most equal to 3.5 mN/m; and
surface tension of the ink to be coated on the substrate is 45 mN/m or more and 60 mN/m or less.

2. The method for manufacturing printed material according to claim 1 , wherein the coating on a substrate is carried out in order of the black ink for lithographic printing, cyan ink for lithographic printing, magenta ink for lithographic printing, and yellow ink for lithographic printing, and tack value (1 minute value) of the black ink for lithographic printing as measured by an inkometer at 38° C. and 400 rpm is 5.0 or more and 8.0 or less.

3. The method for manufacturing printed material according to claim 1 , wherein the method includes a step of curing by active energy ray irradiation.

4. The method for manufacturing printed material according to claim 1 , wherein viscosity (A) at rotation number of 0.5 rpm, viscosity (B) at rotation number of 20 rpm, and viscosity (C) at rotation number of 50 rpm of the ink to be coated on the substrate are all 5 Pa·s or more and 200 Pa·s or less as measured by a cone-plate rotation type viscometer at 25° C., and viscosity ratio (C)/(B) is 0.75 or more and 1.00 or less.

5. The method for manufacturing printed material according to claim 1 , wherein the ink to be coated on the substrate contains a resin having a hydrophilic group, polyfunctional (meth)acrylate, a pigment, and a surfactant.

6. The method for manufacturing printed material according to claim 5 , wherein the hydrophilic group of the resin having a hydrophilic group is any one of a carboxyl group, a sulfo group, a phosphoric acid group, and a hydroxyl group.

7. The method for manufacturing printed material according to claim 5 , wherein acid value of the resin having a hydrophilic group is 30 mgKOH/g or more and 200 mgKOH/g or less.

8. The method for manufacturing printed material according to claim 5 , wherein the polyfunctional (meth)acrylate has a hydroxyl group.

9. The method for manufacturing printed material according to claim 5 , wherein hydroxyl value of the polyfunctional (meth)acrylate is 50 mgKOH/g or more and 200 mgKOH/g or less.

10. The method for manufacturing printed material according to claim 1 , wherein gloss type coated paper is used as the substrate.

11. A lithographic printing ink set comprising at least black ink, cyan ink, magenta ink, and yellow ink, wherein
a difference in surface tension between the inks included in the lithographic printing ink set is at most equal to 3.5 mN/m; and
surface tension of the ink included in the lithographic printing ink set is 45 mN/m or more and 60 mN/m or less.

12. The lithographic printing ink set according to claim 11 , wherein tack value (1 minute value) of the black ink included in the lithographic printing ink set as measured by an inkometer at 38° C. and 400 rpm is 5.0 or more and 8.0 or less.

13. The lithographic printing ink set according to claim 11 , wherein viscosity (A) at rotation number of 0.5 rpm, viscosity (B) at rotation number of 20 rpm, and viscosity (C) at rotation number of 50 rpm of the ink included in the lithographic printing ink set are all 5 Pa·s or more and 200 Pa·s or less as measured by a cone-plate rotation type viscometer at 25° C., and viscosity ratio (C)/(B) is 0.75 or more and 1.00 or less.

14. The lithographic printing ink set according to claim 11 , wherein the ink included in the lithographic printing ink set contains a resin having a hydrophilic group, polyfunctional (meth)acrylate, a pigment, a photopolymerization initiator, and a surfactant.

15. The lithographic printing ink set according to claim 14 , wherein the hydrophilic group of the resin having a hydrophilic group is any one of a carboxyl group, a sulfo group, a phosphoric acid group, and a hydroxyl group.

16. The lithographic printing ink set according to claim 14 , wherein the resin having a hydrophilic has an acid value of 30 mgKOH/g or more and 200 mgKOH/g or less.

17. The lithographic printing ink set according to claim 14 , wherein the polyfunctional (meth)acrylate has a hydroxyl group.

18. The lithographic printing ink set according to claim 14 , wherein hydroxyl value of the polyfunctional (meth)acrylate is 50 mgKOH/g or more and 200 mgKOH/g or less.

19. A printed material printed by using the lithographic printing ink set according to claim 11 .

Assignees

• Toray Industries

Inventors

• KOSHIMIZU Noboru
• Tsuji Yuichi
• Inoue Takejiro

Classifications

• C09D11/107

  from unsaturated acids or derivatives thereof · CPC title

• C09D11/037

  characterised by the pigment · CPC title

• B41M7/0081

  using electromagnetic radiation or waves, e.g. ultraviolet radiation, electron beams · CPC title

• C09D11/101 Primary

  Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing · CPC title

• B41M1/06 Primary

  Lithographic printing · CPC title