US-12624243-B2 - Graft polyurethane copolymer dispersions

Abstract

A graft polyurethane copolymer dispersion can include dispersed polyurethane particles including a graft polyurethane copolymer. The graft polyurethane copolymer in this example includes a polyurethane backbone, a graft side-chain polymer attached to the polyurethane backbone, sulfonic acid groups, and isocyanate-generated amines. The graft side-chain polymer can include a poly(meth)acrylic moieties with C1 to C12 alkyl pendant groups, polyalkylene oxide pendant groups, or a combination thereof.

Inventors

• Zhang-Lin Zhou
• Yubai Bi
• Qianhan Yang

Assignees

• HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P.

Dates

Publication Date

20260512

Application Date

20200110

Claims (17)

1. 1 . A graft polyurethane copolymer dispersion, comprising dispersed polyurethane particles including a graft polyurethane copolymer, wherein the graft polyurethane copolymer consists of: a polyurethane backbone that is either: a) a reaction product of i) a polyisocyanate and ii) a polycarbonate polyol; or b) a reaction product of i) a polyisocyanate and ii) a polyether polyol selected from the group consisting of ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, and polyethylene-polypropylene glycol; or c) a reaction product of i) a polyisocyanate and ii) a polyol selected from the group consisting of a polyether polyol having a weight-average molecular weight of from 700 Mw to 3500 Mw and a polycarbonate polyol; a graft side-chain polymer attached to the polyurethane backbone, wherein the graft side-chain polymer includes poly(meth)acrylic moieties with C1 to C12 alkyl pendant groups, polyalkylene oxide pendant groups, or a combination thereof; sulfonic acid groups; and isocyanate-generated amines, wherein the graft polyurethane copolymer has a weight-average molecular weight ranging from 10,000 Mw to 150,000 Mw.
2. 2 . The graft polyurethane copolymer dispersion of claim 1 , wherein the graft side-chain polymer is attached to the polyurethane backbone via a sulfur-containing linking group.
3. 3 . The graft polyurethane copolymer dispersion of claim 1 , wherein the polyisocyanate includes an isophorone diisocyanate.
4. 4 . The graft polyurethane copolymer dispersion of claim 1 , wherein the isocyanate-generated amines are generated from an excess of the isocyanate groups provided by the polyisocyanate relative to hydroxyl groups provided by the polyol.
5. 5 . An ink composition, comprising: a pigment; an ink vehicle including water and organic co-solvent; and from 1 wt % to 15 wt % of polyurethane particles including a graft polyurethane copolymer based on the total weight of the ink composition, the graft polyurethane copolymer consisting of: a polyurethane backbone that is either: a) a reaction product of i) a polyisocyanate and ii) a polycarbonate polyol; or b) a reaction product of i) a polyisocyanate and ii) a polyether polyol selected from the group consisting of ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, and polyethylene-polypropylene glycol; or c) a reaction product of i) a polyisocyanate and ii) a polyol selected from the group consisting of a polyether polyol having a weight-average molecular weight of from 700 Mw to 3500 Mw and a polycarbonate polyol; a graft side-chain polymer attached to the polyurethane backbone, wherein the graft side-chain polymer includes a poly(meth)acrylic moieties with C1 to C12 alkyl pendant groups, polyalkylene oxide pendant groups, or a combination thereof; sulfonic acid groups; and isocyanate-generated amines, wherein the graft polyurethane copolymer has a weight-average molecular weight ranging from 10,000 Mw to 150,000 Mw.
6. 6 . A multi-fluid kit for imaging, comprising: an ink composition, comprising: a pigment; an ink vehicle including water and organic co-solvent; and from 1 wt % to 15 wt % of polyurethane particles based on a total weight of the ink composition, the polyurethane particles including a graft polyurethane copolymer consisting of a polyurethane backbone, a graft side-chain polymer attached to the polyurethane backbone, sulfonic acid groups, and isocyanate-generated amines, wherein the graft side-chain polymer includes a poly(meth)acrylic moieties with C1 to C12 alkyl pendant groups, polyalkylene oxide pendant groups, or a combination thereof, wherein the graft polyurethane copolymer has a weight-average molecular weight ranging from 10,000 Mw to 150,000 Mw, and wherein the polyurethane backbone is either: a) a reaction product of i) a polyisocyanate and ii) a polycarbonate polyol; or b) a reaction product of i) a polyisocyanate and ii) a polyether polyol selected from the group consisting of ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, and polyethylene-polypropylene glycol; or c) a reaction product of i) a polyisocyanate and ii) a polyol selected from the group consisting of a polyether polyol having a weight-average molecular weight of from 700 Mw to 3500 Mw and a polycarbonate polyol; and a secondary fluid composition.
7. 7 . The multi-fluid kit of claim 6 , wherein the secondary fluid composition is a second ink composition comprising a second pigment colorant of a different color than the pigment colorant.
8. 8 . The multi-fluid kit of claim 6 , wherein the secondary fluid also includes the polyurethane particles having the graft polyurethane copolymer.
9. 9 . The multi-fluid kit of claim 6 , wherein the secondary fluid composition is a fixer composition comprising a cationic compound.
10. 10 . A method of printing, comprising: ejecting an ink composition onto a media substrate, the ink composition including: a pigment; an ink vehicle including water and organic co-solvent; and from 1 wt % to 15 wt % of polyurethane particles based on a total weight of the ink composition, the polyurethane particles including a graft polyurethane copolymer consisting of: a polyurethane backbone that is either: a) a reaction product of i) a polyisocyanate and ii) a polycarbonate polyol; or b) a reaction product of i) a polyisocyanate and ii) a polyether polyol selected from the group consisting of ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, and polyethylene-polypropylene glycol; or c) a reaction product of i) a polyisocyanate and ii) a polyol selected from the group consisting of a polyether polyol having a weight-average molecular weight of from 700 Mw to 3500 Mw and a polycarbonate polyol; a graft side-chain polymer attached to the polyurethane backbone, wherein the graft side-chain polymer includes a poly(meth)acrylic moieties with C1 to C12 alkyl pendant groups, polyalkylene oxide pendant groups, or a combination thereof; sulfonic acid groups; and isocyanate-generated amines, wherein the graft polyurethane copolymer has a weight-average molecular weight ranging from 10,000 Mw to 150,000 Mw.
11. 11 . The method of claim 10 , further comprising ejecting a fixer composition including a cationic compound on the media substrate prior to ejecting the ink composition thereon.
12. 12 . The graft polyurethane copolymer dispersion of claim 1 , wherein the graft side-chain polymer includes the polyalkylene oxide pendant groups.
13. 13 . The graft polyurethane copolymer dispersion of claim 1 , wherein the graft side-chain polymer is the reaction product of thioglycerol, methyl methacrylate, 2-ethylhexyl acrylate, and 2-(2-ethoxyethoxy)ethyl acrylate.
14. 14 . The graft polyurethane copolymer dispersion of claim 1 , wherein the graft side-chain polymer has a weight average molecular weight ranging from 10,000 Mw to 20,000 Mw.
15. 15 . The graft polyurethane copolymer dispersion of claim 1 , wherein the graft polyurethane copolymer is self-crosslinkable through the isocyanate-generated amines.
16. 16 . The graft polyurethane copolymer dispersion of claim 1 , wherein the graft polyurethane copolymer dispersion has an acid number ranging from 39 mg KOH/g to 51.9 mg KOH/g.
17. 17 . The graft polyurethane polymer dispersion of claim 1 , wherein the polyol has a polymer chain and a hydroxyl group at each end of the polymer chain.

Description

BACKGROUND Inkjet printing has become a popular way of recording images on various types of media. Some of the reasons include low printer noise, variable content recording, capability of high-speed recording, and multi-color recording. These advantages can be obtained at a relatively low price to consumers. As the popularity of inkjet printing increases, the types of uses also increase providing demand for new ink compositions and applications. For example, there is a wide variety of packaging applications that could benefit from the use of ink compositions having good durability when printed thereon. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A schematically illustrates an example graft polyurethane copolymer dispersion in accordance with the present disclosure; FIG. 1B schematically illustrates various example chemical groups that can be present on the graft polyurethane copolymers of the example polyurethane particles in accordance with the present disclosure; FIG. 2 schematically illustrates an example graft polyurethane copolymer dispersion in the form of an ink composition in accordance with the present disclosure; FIG. 3 schematically illustrates an example multi-jet fluid kit in accordance with the present disclosure; and FIG. 4 illustrates an example method of printing in accordance with the present disclosure. DETAILED DESCRIPTION Printing for packaging can present some challenges that may not be present when printing on standard papers or other print media. For example, the size and/or dimensions of packaging; packaging color, e.g., dark colors; packaging translucency, e.g., transparent substrate may be assisted by application of white base for printing; packaging configuration, e.g., flexible, corrugated, foldable, etc.; packaging conditions, e.g., heat, pressure, etc.; and the like can present different challenges when printing indicia thereon. Enhancing print durability on a variety of packaging applications can thus provide a versatile printing solution across a wide swath of packaging applications, and in the case of inkjet printing applications, providing good durability while retaining reliable printing characteristics would be useful. In accordance with an example of the present disclosure, a graft polyurethane copolymer dispersion includes dispersed polyurethane particles including a graft polyurethane copolymer including a polyurethane backbone, a graft side-chain polymer attached to the polyurethane backbone, sulfonic acid groups, and isocyanate-generated amines. The graft side-chain polymer in this example includes a poly(meth)acrylic moieties with C1 to C12 alkyl pendant groups, polyalkylene oxide pendant groups, or a combination thereof. In one example, the graft polyurethane copolymer can be devoid of carboxylic acid. In another example, when the graft polyurethane copolymer includes carboxylic acid groups, the carboxylic acid groups are are present at a molar ratio of sulfonic acid groups to carboxylic acid groups of 2:1 or more, e.g., as the ratio increases, the carboxylic acid molar concentration is reduced relative to the sulfonic acid molar concentration. The graft side-chain polymer can be attached to the polyurethane backbone via a sulfur-containing linking group. In further detail, the polyurethane backbone can include a reaction product of polyisocyanates with polycarbonate polyols or polyether polyols, e.g., an isophorone diisocyanate, in addition to graft side-chain polymeric diols used to generate the graft side-chain polymer. The polyurethane backbone can include a reaction product of polyisocyanates with polyols, wherein the isocyanate-generated amines are generated from a 10 wt % to 25 wt % molar excess of the isocyanate groups provided by polyisocyanates relative to hydroxyl groups provided by the polyols. In another example, the graft polyurethane copolymer dispersion is in the form of an ink composition. The ink composition in this example includes a pigment, an ink vehicle including water and organic co-solvent, and from 1 wt % to 15 wt % of the polyurethane particles with the graft polyurethane copolymer based on the total weight of the ink composition. The graft polyurethane copolymer in this example includes a polyurethane backbone, a graft side-chain polymer attached to the polyurethane backbone, wherein the graft side-chain polymer includes a poly(meth)acrylic moieties with C1 to C12 alkyl pendant groups, polyalkylene oxide pendant groups, or a combination thereof, sulfonic acid groups, and isocyanate-generated amines. In another example, a multi-fluid kit for imaging includes an ink composition and a second fluid composition. The ink composition, for example, includes a pigment, an ink vehicle including water and organic co-solvent, and from 1 wt % to 15 wt % polyurethane particles based on the total weight of the ink composition. The polyurethane particles in this example include a graft polyurethane copolymer with a polyurethane backbone, a graft side-chain