A pigment dispersion for an inkjet ink contains pigment particles, styrene-acrylic resin, and water. The styrene-acrylic resin includes a first repeating unit having a group represented by formula (1) and a second repeating unit not having a repeating unit represented by formula (1).

##STR00001##

The first repeating unit has a percentage content to the total mass of the first repeating unit and the second repeating unit of at least 1% by mass and no greater than 10% by mass. In formula (1), R.sup.1 represents a hydrogen atom or a methyl group, R.sup.2 represents a hydrogen atom or an alkyl group with a carbon number of at least 1 and no greater than 7, and m.sub.1 represents an integer of at least 4 and no greater than 9.

Ink compositions and methods of use for reliably printing on alkaline and readily oxidizing surfaces comprise one or more pigments, one or more solvents for adjusting viscosity, surface tension, and/or heat tolerance, and water, the pigments being “loaded” in the ink sufficiently to meet the relevant color and optical density requirements for the ink while such ink composition still also meets the duty cycle requirements of the application.

Ink compositions and methods of use for reliably printing on alkaline and readily oxidizing surfaces comprise one or more pigments, one or more solvents for adjusting viscosity, surface tension, and/or heat tolerance, and water, the pigments being “loaded” in the ink sufficiently to meet the relevant color and optical density requirements for the ink while such ink composition still also meets the duty cycle requirements of the application.

An ink jet recording method includes: a treatment liquid adhesion step of adhering a treatment liquid containing an aggregating agent to a recording medium; an ink adhesion step of adhering an aqueous ink composition containing a colorant to the recording medium by ejection thereof from an ink jet head; a first heating step of heating the recording medium to which the treatment liquid and the aqueous ink composition are adhered to a first surface temperature by a first heating mechanism; a second heating step of heating the recording medium after the first heating step to a second surface temperature which is higher than the first surface temperature by a second heating mechanism provided at downstream than the first heating mechanism in a recording medium transport direction; and a cooling step of, after the first heating step and before the second heating step, cooling the recording medium by a cooling mechanism, and by the cooling step, a surface temperature of the recording medium is decreased to a temperature lower than the first surface temperature.

An ink jet recording method includes: a treatment liquid adhesion step of adhering a treatment liquid containing an aggregating agent to a recording medium; an ink adhesion step of adhering an aqueous ink composition containing a colorant to the recording medium by ejection thereof from an ink jet head; a first heating step of heating the recording medium to which the treatment liquid and the aqueous ink composition are adhered to a first surface temperature by a first heating mechanism; a second heating step of heating the recording medium after the first heating step to a second surface temperature which is higher than the first surface temperature by a second heating mechanism provided at downstream than the first heating mechanism in a recording medium transport direction; and a cooling step of, after the first heating step and before the second heating step, cooling the recording medium by a cooling mechanism, and by the cooling step, a surface temperature of the recording medium is decreased to a temperature lower than the first surface temperature.

The ink jet recording method includes ejecting an aqueous ink from a recording head to apply the aqueous ink to a recording medium, to thereby record an image. The ink jet recording method includes: ejecting the aqueous ink heated to a temperature T.sub.H (° C.) from the recording head to apply the aqueous ink to the recording medium; and heating the recording medium having the aqueous ink applied thereto to a temperature T.sub.F (° C.), the aqueous ink containing a pigment and a polyester resin particle, a glass transition temperature T.sub.G (° C.) of the polyester resin particle, the temperature T.sub.H (° C.) and the temperature T.sub.F (° C.) satisfying relationships of the following expressions (1) to (3).

T.sub.G(° C.)>T.sub.H(° C.)   (1)

T.sub.F(° C.)≥T.sub.H(° C.)+10° C.   (2)

T.sub.F(° C.)≥T.sub.G(° C.)−10° C.   (3)

The present invention provides an aqueous ink comprising one or more film forming agents, wherein the total film forming agent concentration in the aqueous ink is from 0.1 to 30 wt. %, and optionally one or more emulsifiers, preferably wherein the total emulsifier concentration in the aqueous ink is from 0.1 to 10 wt. %. The one or more emulsifiers, if present, are fatty acid esters of polyalkoxylated sorbitan and/or the one or more film forming agents fulfil at least one of the following properties: a Young modulus of at least 2 GPa, and a nano hardness of at least 0.08 GPa. Also provided is a use thereof for inkjet printing, preferably on a corrugated board or on a liner for the production of corrugated board.

The present invention provides an aqueous ink comprising one or more film forming agents, wherein the total film forming agent concentration in the aqueous ink is from 0.1 to 30 wt. %, and optionally one or more emulsifiers, preferably wherein the total emulsifier concentration in the aqueous ink is from 0.1 to 10 wt. %. The one or more emulsifiers, if present, are fatty acid esters of polyalkoxylated sorbitan and/or the one or more film forming agents fulfil at least one of the following properties: a Young modulus of at least 2 GPa, and a nano hardness of at least 0.08 GPa. Also provided is a use thereof for inkjet printing, preferably on a corrugated board or on a liner for the production of corrugated board.

A printed matter exhibiting metallic gloss is provided and includes: a substrate; and a metallic glossy layer, being formed on the substrate, and the metallic glossy layer containing scaly particles having a metal. In the metallic glossy layer, the scaly particles are oriented to be substantially parallel to a surface of the metallic glossy layer; and the surface of the metallic glossy layer has a DOI value of greater than or equal to 20% and a Sa value of less than or equal to 2 μm.

A method of preparation of a gold electrode, which includes the steps of: a) inkjet printing on a substrate an ink including gold nanoparticles functionalized with a compound Cap of formula (I) HS-A-Polyalkylene glycol (I), wherein A is a bound or an alkyl chain having 1 to 12 carbon atoms and wherein polyalkylene glycol is polyethylene glycol, polypropylene glycol or a mixture thereof; and b) annealing printed ink, wherein the compound Cap has an average molar mass of less than 500 g/mol, preferably an average molar mass of about 200 g/mol. Also, an electrode obtainable by the method of the invention, a sensor including the electrode and the use of the sensor.