Provided is an ABA block copolymer that can offer a pigment dispersion composition having excellent dispersion stability when used as a pigment dispersant in an aqueous medium. An ABA block copolymer including: an A block containing a structural unit represented by a general formula (1) below and a structural unit derived from a vinyl monomer with an acid group; and a B block containing a structural unit derived from a vinyl monomer with an aromatic ring group or an alicyclic alkyl group, the ABA block copolymer having an acid value of 30 to 250 mgKOH/g. ##STR00001##
In the general formula (1), R.sup.1 is a hydrogen atom or a methyl group and R.sup.2 is an alkyl group having 2 to 10 carbon atoms.

Aqueous ink compositions and methods for fabricating a resistive material for a printed circuit are provided. The aqueous ink composition may include an aqueous solvent, one or more carbon nanoparticles, and one or more cellulose nanocrystals. The one or more carbon nanoparticles may include carbon nanotubes, such as multi-walled nanotubes, and the one or more cellulose nanocrystals may include cellulose nanocrystals functionalized with carboxylate groups.

Aqueous ink compositions and methods for fabricating a resistive material for a printed circuit are provided. The aqueous ink composition may include an aqueous solvent, one or more carbon nanoparticles, and one or more cellulose nanocrystals. The one or more carbon nanoparticles may include carbon nanotubes, such as multi-walled nanotubes, and the one or more cellulose nanocrystals may include cellulose nanocrystals functionalized with carboxylate groups.

The present disclosure is drawn to aqueous pigment dispersions. In one example, an aqueous pigment dispersion can include from 40 wt % to 90 wt % water, from 2 wt % to 30 wt % organic co-solvent, from 7.5 wt % to 30 wt % copper phthalocyanine pigment, from 0.5 wt % to 5 wt % styrene-acrylic dispersant, and from 0.5 wt % to 5 wt % hydrophilic polyurethane dispersant having a weight average molecular weight from 10,000 Mw to 30,000 Mw. The styrene-acrylic dispersant and the hydrophilic polyurethane dispersant can be present at a weight ratio from 1:10 to 2:1.

The present disclosure is drawn to aqueous pigment dispersions. In one example, an aqueous pigment dispersion can include from 40 wt % to 90 wt % water, from 2 wt % to 30 wt % organic co-solvent, from 7.5 wt % to 30 wt % copper phthalocyanine pigment, from 0.5 wt % to 5 wt % styrene-acrylic dispersant, and from 0.5 wt % to 5 wt % hydrophilic polyurethane dispersant having a weight average molecular weight from 10,000 Mw to 30,000 Mw. The styrene-acrylic dispersant and the hydrophilic polyurethane dispersant can be present at a weight ratio from 1:10 to 2:1.

An ink contains water, a coloring material, and a polymer having a structure unit represented by the following Chemical formula 1 and a structure unit having an anionic group,

##STR00001## where R.sub.1 represents a hydrogen atom or a methyl group, L.sub.1 is an alkylene group having three to five carbon atoms having a hydroxyl group, L.sub.2 is an alkylene group having two to ten carbon atoms, and Ar represents a phenyl group, a biphenyl group, or a naphthyl group.

An ink contains water, a coloring material, and a polymer having a structure unit represented by the following Chemical formula 1 and a structure unit having an anionic group,

##STR00001## where R.sub.1 represents a hydrogen atom or a methyl group, L.sub.1 is an alkylene group having three to five carbon atoms having a hydroxyl group, L.sub.2 is an alkylene group having two to ten carbon atoms, and Ar represents a phenyl group, a biphenyl group, or a naphthyl group.

A pre-treatment fixing fluid for an offset coated medium is disclosed. The pre-treatment fixing fluid includes calcium-containing cationic crashing agents consisting of calcium propionate and calcium nitrate, wherein the calcium propionate is present in an amount ranging from about 0 wt % to about 10 wt %, and wherein the calcium nitrate is present in an amount ranging from about 15 wt % to 0 wt %, both based on the total wt % of the pre-treatment fixing fluid. The pre-treatment fixing further includes a co-solvent, a surfactant, and a balance of water. The surfactant is selected from the group consisting of a first surfactant having a first hydrophilic lipophilic balance (HLB) value within a hydrophobic range and a combination of the first surfactant and a second surfactant having a second HLB value within a water dispersible range.

A pre-treatment fixing fluid for an offset coated medium is disclosed. The pre-treatment fixing fluid includes calcium-containing cationic crashing agents consisting of calcium propionate and calcium nitrate, wherein the calcium propionate is present in an amount ranging from about 0 wt % to about 10 wt %, and wherein the calcium nitrate is present in an amount ranging from about 15 wt % to 0 wt %, both based on the total wt % of the pre-treatment fixing fluid. The pre-treatment fixing further includes a co-solvent, a surfactant, and a balance of water. The surfactant is selected from the group consisting of a first surfactant having a first hydrophilic lipophilic balance (HLB) value within a hydrophobic range and a combination of the first surfactant and a second surfactant having a second HLB value within a water dispersible range.

Disclosed herein is a three-dimensional printing method comprising: applying a build material; applying on, at least, a portion of the build material, a low tint fusing agent composition comprising metal oxide nanoparticles dispersed in a liquid vehicle; and exposing the build material to radiations to fuse the portion of the build material in contact with the low tint fusing agent composition in order to form a layer of a 3D object. Also disclosed herein is an article obtained according to the three-dimensional printing method described herein. Such articles comprises a core substrate made of a polymeric build material that has been fused with a core fusing agent composition; a first layer, applied on the surface of the core substrate, comprising a polymeric build material fused with a low tint fusing agent composition including metal oxide nanoparticles dispersed in a liquid vehicle; and a second layer, applied over the surface of the first layer, comprising a polymeric build material fused with a colored ink composition and a core fusing agent or with a low tint fusing agent composition colored ink composition.