THERMAL INKJET INK SET

• US 20160319147A1
• Filed: 01/28/2014
• Published: 11/03/2016
• Est. Priority Date: 01/28/2014
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: CHEN, Tienteh, VISNYAK, Elizabeth Ann, PRASAD, Keshava A.
• Granted Patent: US 9,738,808 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B41J 11/0015 for treating before, during or after printing or for uniform coating or laminating the copy material before or after printing selective coating B41J2/2114
• CPC Class Codes: 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
• CPC Class Codes: B41M 7/0036 using protective coatings or layers dried without curing
• CPC Class Codes: C09D 11/10 based on artificial resins
• CPC Class Codes: C09D 11/107 from unsaturated acids or derivatives thereof
• CPC Class Codes: C09D 11/322 Pigment inks
• CPC Class Codes: C09D 11/40 Ink-sets specially adapted for multi-colour inkjet printing
• CPC Class Codes: C09D 11/54 Inks based on two liquids, one liquid being the ink, the other liquid being a reaction solution, a fixer or a treatment solution for the ink

Abstract

A thermal inkjet ink set includes a pre-treatment fixing fluid, an ink, and a post-treatment fluid. The pre-treatment fixing fluid includes a metal salt. The ink includes an ink vehicle and a colorant. The post-treatment fluid includes a fluid vehicle and an anionic polyurethane acrylic hybrid polymer binder dispersed in the fluid vehicle. The anionic polyurethane acrylic hybrid polymer binder is present in an amount ranging from greater than 0 wt % to about 25 wt %. The anionic polyurethane acrylic hybrid polymer binder includes an acrylic polymer or copolymer, and an anionic polyurethane polymer encapsulating the acrylic polymer or copolymer.

Claims

1. A thermal inkjet ink set, comprising:

a pre-treatment fixing fluid including a metal salt;

an ink including an ink vehicle and a colorant; and

a post-treatment fluid including a fluid vehicle and an anionic polyurethane acrylic hybrid polymer binder dispersed in the fluid vehicle, the anionic polyurethane acrylic hybrid polymer binder present in an amount ranging from greater than 0 wt % to about 25 wt %, and the anionic polyurethane acrylic hybrid polymer binder including;

an acrylic polymer or copolymer; and

an anionic polyurethane polymer encapsulating the acrylic polymer or copolymer.

2. The thermal inkjet ink set as defined in claim 1 wherein the polyurethane acrylic hybrid polymer binder includes at least 70 wt % of the acrylic polymer or copolymer and 30 wt % or less of the anionic polyurethane polymer.

3. The thermal inkjet ink set as defined in claim 1 wherein the acrylic polymer or copolymer is selected from the group consisting of a copolymer of methyl methacrylate and n-butyl acrylate, a copolymer of ethyl acrylate and n-butyl acrylate, a copolymer of styrene and n-butyl acrylate, a copolymer of styrene, n-butyl acrylate, and methyl methacrylate, a copolymer of cyclohexane methacrylate and n-butyl acrylate, a copolymer of t-butyl methacrylate and n-butyl acrylate, and a copolymer of methyl methacrylate, n-butyl acrylate, and ethylene diacrylate.

4. The thermal inkjet ink set as defined in claim 1 wherein a Tg of the acrylic polymer or copolymer ranges from about −

30°

C. to about 100°

C.

5. The thermal inkjet ink set as defined in claim 1 wherein each of the treatment fixing fluid, the ink, and post-treatment fluid are contained in separate ink cartridges.

6. The thermal inkjet ink set as defined in claim 1 wherein the anionic polyurethane polymer has a molecular weight ranging from about 5,000 to about 70,000.

7. The thermal inkjet ink set as defined in claim 1 wherein:

the anionic polyurethane acrylic hybrid polymer binder is a particle having a core shell morphology;

the acrylic polymer or copolymer forms a core of the particle; and

the anionic polyurethane polymer forms a shell of the particle.

8. The thermal inkjet ink set as defined in claim 1 wherein the anionic polyurethane polymer includes:

a polyisocyanate segment;

a polyol segment having a number average molecular weight ranging from about 500 to about 6,000;

a compound including i) an ionic group or ii) a group to form an ionic group;

optionally a diol or triol having a number average molecular weight ranging from about 62 to about 500; and

optionally a second polyol segment having a polyethyleneoxide functional group.

9. The thermal inkjet ink set as defined in claim 8 wherein:

the polyisocyanate segment is isophorone diisocyanate;

the polyol segment is selected from the group consisting of polytetrahydrofuran, polypropyleneglycol, polycarbonate polyol, a mixture of polytetrahydrofuran and monodicarbinol terminated polydimethylsiloxane, and a mixture of polytetrahydrofuran and carbinol (hydroxyl) terminated polydimethylsiloxane;

the compound including i) the ionic group or ii) the group to form an ionic group is selected from the group consisting of 2,2′

-dimethyloyl propionic acid, taurine, and mixtures thereof;

the diol or triol is selected from the group consisting of cyclohexane dimethyol, a mixture of cyclohexane dimethyol and hydroxyethyl acrylate, and 3-methyl-1,5-pentanediol; and

the second polyol segment is polyethyleneoxide diol.

10. The thermal inkjet ink set as defined in claim 1 wherein the fluid vehicle consists of:

a co-solvent selected from the group consisting of Di-(2-Hydroxyethyl)-5,5-Dimethylhydantoin, N-(2-Hydroxyethyl)-2-pyrrolidone, hydroxyethyl urea, 1,2,6-hexanetriol, 1,2,4-butanetriol, tetraethylene glycol, 2-methyl-2-hydroxymethyl-1,3-propandiol, and combinations thereof;

a surfactant;

optionally an additive selected from the group consisting of an anti-kogation agent, a wax, a biocide, and combinations thereof; and

a balance of water.

11. The thermal inkjet ink set as defined in claim 1 wherein the colorant of the ink is an anionically dispersed pigment.

12. A printing method, comprising:

separately depositing onto a medium, in order with a thermal inkjet printer, a pre-treatment fixing fluid, an ink, and a post-treatment fluid including a fluid vehicle and an anionic polyurethane acrylic hybrid polymer binder dispersed in the fluid vehicle, the anionic polyurethane acrylic hybrid polymer binder present in an amount ranging from greater than 0 wt % to about 25 wt %, and the anionic polyurethane acrylic hybrid polymer binder including;

an acrylic polymer or copolymer; and

an anionic polyurethane polymer shell encapsulating the acrylic polymer or copolymer.

13. The printing method as defined in claim 12, further comprising performing a drying operation after the depositing of the ink and before the depositing of the post-treatment fluid.

14. The printing method as defined in claim 12 wherein the depositing of the post-treatment fluid is performed before the ink and the pre-treatment fixing fluid are dry.

15. The printing method as defined in claim 12 wherein:

the depositing of the pre-treatment fixing fluid includes jetting the pre-treatment fixing fluid from a first inkjet ink cartridge;

the depositing of the ink includes jetting the ink from a second inkjet ink cartridge; and

the depositing of the post-treatment fluid includes jetting the post-treatment from a third inkjet ink cartridge.