Hydrogel three-dimensional printing kits, methods of three-dimensional printing and three-dimensional printed hydro-gels are described. In one example, a three-dimensional printing kit can comprise a particulate build material, a crosslinking agent and a structural modifier. The particulate build material may comprise a polyhydroxylated polymer having hydroxyl groups. The crosslinking gent is for crosslinking the polyhydroxylated polymer by a reaction with the hydroxyl groups. The structural modifier can have a plurality of functional groups for forming a network within the hydrogel, and where the structural modifier may have a reactivity that is chemically orthogonal to the reaction with the hydroxyl groups for crosslinking the polyhydroxylated polymer.

Hydrogel three-dimensional printing kits, methods of three-dimensional printing and three-dimensional printed hydro-gels are described. In one example, a three-dimensional printing kit can comprise a particulate build material, a crosslinking agent and a structural modifier. The particulate build material may comprise a polyhydroxylated polymer having hydroxyl groups. The crosslinking gent is for crosslinking the polyhydroxylated polymer by a reaction with the hydroxyl groups. The structural modifier can have a plurality of functional groups for forming a network within the hydrogel, and where the structural modifier may have a reactivity that is chemically orthogonal to the reaction with the hydroxyl groups for crosslinking the polyhydroxylated polymer.

An ink set has two or more aqueous pigment-based inks, each of which has 75-95 weight %, a) one or more pigment colorants, and b) one or more water-miscible humectants that are present in a total amount of at least 1 weight % and up to and including 20 weight %, and consist essentially of compounds, each of which has a carbon atom to oxygen atom ratio of at least 1.0:1.0 and only two hydroxy groups. The weight % amounts of water and the b) water-miscible humectants are based on the total weight of each aqueous pigment-based ink. The aqueous pigment-based inks in the ink set can be used individual or in combination to provide monochrome or polychrome inkjet-printed images on various ink-receptive media and using various inkjet printing equipment and methods.

An ink set has two or more aqueous pigment-based inks, each of which has 75-95 weight %, a) one or more pigment colorants, and b) one or more water-miscible humectants that are present in a total amount of at least 1 weight % and up to and including 20 weight %, and consist essentially of compounds, each of which has a carbon atom to oxygen atom ratio of at least 1.0:1.0 and only two hydroxy groups. The weight % amounts of water and the b) water-miscible humectants are based on the total weight of each aqueous pigment-based ink. The aqueous pigment-based inks in the ink set can be used individual or in combination to provide monochrome or polychrome inkjet-printed images on various ink-receptive media and using various inkjet printing equipment and methods.

The present invention relates to an ink-jet printing method of overprinting a first ink and a second ink on a low-liquid absorbing printing medium, in which the first ink and the second ink are respectively in the form of a water-based ink containing a colorant (A), a polymer (B), an organic solvent (C) and water, and satisfy the following formulae (1) and (2), said ink-jet printing method including the steps of forming characters or images using at least one ink as the first ink, and then forming a background image using the second ink such that the background image is superimposed on at least a part of the characters or images formed by the first ink: [T.sub.2−T.sub.1]<0 mN/m (1); and [V.sub.2−V.sub.1]≥1.0 mPa.Math.s (2) wherein T.sub.2 is the static surface tension of the second ink; T.sub.1 is the static surface tension of the first ink; V.sub.2 is the viscosity of the second ink as measured at 32° C.; and V.sub.1 is the viscosity of the first ink as measured at 32° C. According to the method of the present invention, it is possible to obtain good printed characters or images that are excellent in uniformity of solid image printing and suffer from less intercolor bleeding.

The present invention relates to [1] an aqueous composition for ink-jet printing containing a carbodiimide compound, a vinyl polymer and water, in which the vinyl polymer is dispersed in the aqueous composition in the form of polymer particles formed by partially neutralizing carboxy groups of the vinyl polymer with a basic compound having a boiling point of not higher than 130° C.; [2] an ink set for ink-jet printing containing an aqueous composition a containing a carbodiimide compound and water, and an aqueous composition b containing a vinyl polymer; and [3] an ink-jet printing method including the step 1 of ejecting a carbodiimide compound, a pigment, a vinyl polymer and water by an ink-jetting method to print characters or images, and the step 2 of subjecting the resulting printed characters or images to heat treatment at a temperature of 50 to 200° C. According to the aqueous composition of the present invention, it is possible to obtain a printed material that is excellent in rub fatness.

A metallic nanoparticle composition includes copper nanoparticles, a first non-aqueous polar protic solvent (boiling point in a range of 180° C. to 250° C. and viscosity in a range of 10 cP to 100 cP at 25° C.), and a second non-aqueous polar protic solvent (boiling point in a range of 280° C. to 300° C. and a viscosity of at least 100 cP at 25° C.). The concentration of copper nanoparticles in the composition is in a range of 32 wt % to 55 wt %, and the concentration of the second non-aqueous polar protic solvent in the composition is in a range of 4 wt % to 10 wt %. There is polyvinylpyrrolidone present on the copper nanoparticles surfaces. The composition's viscosity is at least 250 cP at 25° C.

A metallic nanoparticle composition includes copper nanoparticles, a first non-aqueous polar protic solvent (boiling point in a range of 180° C. to 250° C. and viscosity in a range of 10 cP to 100 cP at 25° C.), and a second non-aqueous polar protic solvent (boiling point in a range of 280° C. to 300° C. and a viscosity of at least 100 cP at 25° C.). The concentration of copper nanoparticles in the composition is in a range of 32 wt % to 55 wt %, and the concentration of the second non-aqueous polar protic solvent in the composition is in a range of 4 wt % to 10 wt %. There is polyvinylpyrrolidone present on the copper nanoparticles surfaces. The composition's viscosity is at least 250 cP at 25° C.

A barium titanate fiber is useful as a filler for a polymer composite piezoelectric body, a polymer composite piezoelectric body has high piezoelectric properties, and a piezoelectric element utilizes the polymer composite piezoelectric body. In the barium titanate fiber, the molar ratio of barium atoms to titanium atoms (Ba/Ti ratio) falls within the range of 1.01 to 1.04. The polymer composite piezoelectric body includes a resin composition containing the barium titanate fiber and a polymer. The piezoelectric element including an electrically conductive layer on one surface or both surfaces of the polymer composite piezoelectric body.

A barium titanate fiber is useful as a filler for a polymer composite piezoelectric body, a polymer composite piezoelectric body has high piezoelectric properties, and a piezoelectric element utilizes the polymer composite piezoelectric body. In the barium titanate fiber, the molar ratio of barium atoms to titanium atoms (Ba/Ti ratio) falls within the range of 1.01 to 1.04. The polymer composite piezoelectric body includes a resin composition containing the barium titanate fiber and a polymer. The piezoelectric element including an electrically conductive layer on one surface or both surfaces of the polymer composite piezoelectric body.