Liquid electrophotographic varnish composition

Patent metadata

Field	Value
Publication number	US-10168629-B2
Application number	US-201515539935-A
Country	US
Kind code	B2
Filing date	Jan 19, 2015
Priority date	Jan 19, 2015
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A liquid electrophotographic varnish composition comprising: a polymer resin; an epoxy-based cross-linking agent; a solid catalyst comprising at least one amine group; and a carrier liquid.

First claim

The invention claimed is:

1. A liquid electrophotographic varnish composition, comprising:
a polymer resin comprising a polymer having acidic side groups;
an epoxy-based cross-linking agent;
a solid catalyst comprising at least one amine group;
a carrier liquid; and
a metal catalyst and/or a photoinitiator;
wherein the composition is substantially colorless.

2. The composition as claimed in claim 1 , wherein the catalyst comprises more than one amine group.

3. The composition as claimed in claim 1 , wherein the catalyst comprises a primary or secondary amine group.

4. The composition as claimed in claim 3 , wherein the catalyst comprises a guanidine or urea group.

5. The composition as claimed in claim 1 , wherein the catalyst is selected from 2-cyanoguanidine, methylene diphenyl bis(dimethyl urea), melamine and cyanamide.

6. The composition as claimed in claim 1 , wherein the catalyst has a melting point of above 80 degrees C.

7. The composition as claimed in claim 1 , which comprises 0.5 to 20 weight % of the catalyst.

8. The composition as claimed in claim 1 , wherein the epoxy-based cross-linking agent is present in an amount of 0.5 to 20 wt % based on the total weight of solids in the composition.

9. The composition as claimed in claim 1 , wherein the epoxy-based cross-linking agent is selected from 1,2,7,8-diepoxy octane, trimethylolpropane triglycidyl ether, resorcinol diglycidyl ether, N,N-diglycidyl-4-glycidyloxyaniline, 4,4′-Methylenebis(N,N-diglycidylaniline), tris(4-hydroxyphenyl)methane triglycidyl ether, diglycidyl 1,2-cyclohexanedicarboxylate, 1,4-cyclohexanedimethanol diglycidyl ether, tris(2,3-epoxypropyl) isocyanurate, neopentyl glycol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol A propoxylate diglycidyl ether, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, poly[(o-cresyl glycidyl ether)-co-formaldehyde], poly(ethylene-co-glycidyl methacrylate), poly(ethylene-co-methyl acrylate-co-glycidyl methacrylate), poly(bisphenol A-co-epichlorohydrin) glycidyl end-capped, poly(ethylene glycol) diglycidyl ether, and poly(propylene glycol) diglycidyl ether.

10. A method of electrophotographic printing, said method comprising printing the liquid electrophotographic varnish composition of claim 1 onto a substrate using a liquid electrophotographic printer.

11. The method as claimed in claim 10 , which comprises curing the printed electrophotographic varnish composition by subjecting the printed composition to heat.

12. The composition as claimed in claim 1 , wherein the composition is transparent.

13. A liquid electrophotographic varnish composition, comprising:
a polymer resin comprising a polymer having acidic side groups and having an acidity of 50 mg KOH/g or more;
an epoxy-based cross-linking agent;
a solid catalyst comprising at least one amine group; and
a carrier liquid;
wherein the composition is substantially colorless.

14. The composition as claimed in claim 13 , wherein the polymer having acidic side groups is selected from (i) ethylene or propylene acrylic acid co-polymers and (ii) ethylene or propylene methacrylic acid co-polymers.

15. The composition as claimed in claim 13 , wherein the solid catalyst has the general formula:

where:
Ra and Rb are each independently selected from the group consisting of hydrogen, and a C 1 to C 6 alkyl;
Rc is hydrogen; and
Rd is a hydrocarbyl group that is optionally substituted with a nitrogen-containing group.

16. The composition as claimed in claim 13 , wherein the catalyst is methylene diphenyl bis(dimethyl urea).

17. A liquid electrophotographic varnish composition, comprising:
a polymer resin comprising a polymer having acidic side groups;
an epoxy-based cross-linking agent;
a solid catalyst comprising at least one amine group;
a carrier liquid; and
a charge adjuvant;
wherein the composition is substantially colorless.

18. The composition as claimed in claim 17 wherein:
the solid catalyst is selected from 2-cyanoguanidine, methylene diphenyl bis(dimethyl urea), melamine and cyanamide; and
the epoxy-based cross-linking agent is selected from 1,2,7,8-diepoxy octane, trimethylolpropane triglycidyl ether, resorcinol diglycidyl ether, N,N-diglycidyl-4-glycidyloxyaniline, 4,4′-Methylenebis(N,N-diglycidylaniline), tris(4-hydroxyphenyl)methane triglycidyl ether, diglycidyl 1,2-cyclohexanedicarboxylate, 1,4-cyclohexanedimethanol diglycidyl ether, tris(2,3-epoxypropyl) isocyanurate, neopentyl glycol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol A propoxylate diglycidyl ether, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, poly[(o-cresyl glycidyl ether)-co-formaldehyde], poly(ethylene-co-glycidyl methacrylate), poly(ethylene-co-methyl acrylate-co-glycidyl methacrylate), poly(bisphenol A-co-epichlorohydrin) glycidyl end-capped, poly(ethylene glycol) diglycidyl ether, and poly(propylene glycol) diglycidyl ether.

Assignees

• Hp Indigo Bv

Inventors

• Azzam Tony
• Mor Ilanit
• Farran Samer
• Teishev Albert
• Nesher Guy
• Biadglin Getahun
• Cohen Haim
• Dayan Benjamin
• Kowal-Blau Yael
• Shelef Eyal

Classifications

• G03G9/12

  in liquid developer mixtures · CPC title

• G03G7/004

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• G03G9/13

  characterised by polymer components · CPC title

• G03G7/002 Primary

  Organic components thereof · CPC title

• G03G9/131

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title