A colored special effect ink includes a special effect pigment and a colored pigment. The colored pigment is more hydrophobic than the special effect pigment, and the colored pigment is miscible in a solvent chosen from the group consisting of alcohols, ethers, esters, ketones, and water. The colored pigment optionally has a surface energy of less than 35 dynes/cm. A method for preparing the colored special effect ink and treating the colored pigment to form the colored special effect ink are also described.

A colored special effect ink includes a special effect pigment and a colored pigment. The colored pigment is more hydrophobic than the special effect pigment, and the colored pigment is miscible in a solvent chosen from the group consisting of alcohols, ethers, esters, ketones, and water. The colored pigment optionally has a surface energy of less than 35 dynes/cm. A method for preparing the colored special effect ink and treating the colored pigment to form the colored special effect ink are also described.

The present invention provides a process for producing a fine organic pigment which is capable of efficiently atomizing a raw material organic pigment, and excellent in productivity of the fine organic pigment. The present invention relates to a process for producing a fine organic pigment which includes the step of kneading a mixture prepared by compounding a raw material organic pigment, a water-soluble inorganic salt, a water-soluble organic solvent and a resin, in which the resin is a copolymer produced by copolymerizing an aromatic ring-containing ethylenically unsaturated monomer (A), a carboxy group-containing ethylenically unsaturated monomer (B) and an ethylenically unsaturated monomer (C) containing a polyethyleneoxide chain having an average molar number of addition of ethyleneoxide of not less than 1 and not more than 50.

The present invention provides a process for producing a fine organic pigment which is capable of efficiently atomizing a raw material organic pigment, and excellent in productivity of the fine organic pigment. The present invention relates to a process for producing a fine organic pigment which includes the step of kneading a mixture prepared by compounding a raw material organic pigment, a water-soluble inorganic salt, a water-soluble organic solvent and a resin, in which the resin is a copolymer produced by copolymerizing an aromatic ring-containing ethylenically unsaturated monomer (A), a carboxy group-containing ethylenically unsaturated monomer (B) and an ethylenically unsaturated monomer (C) containing a polyethyleneoxide chain having an average molar number of addition of ethyleneoxide of not less than 1 and not more than 50.

The present invention describes a method to obtain magnetic aqueous ink composition for MICR (Magnetic Ink Character Recognition) ink jet printing comprising an aqueous dispersion of functionalized magnetic nanoparticles, humectant agents, solvents, biocide and water. It also allows obtaining stable inks for long periods with extremely high concentrations of magnetic nanoparticles with loading between 15% and 40% by mass and magnetic signals varying from 80 to 200%. Through the use and special combination of humectant agents, the present inventions increase the print head protection, by decreasing abrasiveness and increasing fluidity. The resulting ink has superior printing quality and increased service life of the printing system.

The present invention describes a method to obtain magnetic aqueous ink composition for MICR (Magnetic Ink Character Recognition) ink jet printing comprising an aqueous dispersion of functionalized magnetic nanoparticles, humectant agents, solvents, biocide and water. It also allows obtaining stable inks for long periods with extremely high concentrations of magnetic nanoparticles with loading between 15% and 40% by mass and magnetic signals varying from 80 to 200%. Through the use and special combination of humectant agents, the present inventions increase the print head protection, by decreasing abrasiveness and increasing fluidity. The resulting ink has superior printing quality and increased service life of the printing system.

An aqueous ink composition includes an aqueous medium and resin microparticles formed from a resin, in which the resin has a structural unit represented by General Formula (1) or (2), and the content of the resin microparticles is 1% to 15% by mass,

##STR00001## R.sup.1, R.sup.2, and R.sup.3 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; A.sup.1 represents —O— or —NR.sup.3—; L.sup.1 represents an alkylene group having 6 to 22 carbon atoms; M.sup.1 and M.sup.2 each represent a hydrogen atom, an alkali metal ion, or an ammonium ion; A.sup.2 represents a single bond, —COO—, or —CONH—; and L.sup.2 represents a divalent linking group having 6 to 23 carbon atoms.

The present disclosure provides white pigment dispersions, which can include an aqueous liquid vehicle, and from 5 wt % to 70 wt % of a white metal oxide pigment dispersed by two co-dispersants. The metal oxide pigment can have an average particulate size from 100 nm to 1 μm, and the co-dispersants can include both i) a short-chain anionic dispersant having a weight average molecular weight ranging from 1,000 Mw to 30,000 Mw, and ii) a non-ionic or predominantly non-ionic dispersant.

The present disclosure provides white pigment dispersions, which can include an aqueous liquid vehicle, and from 5 wt % to 70 wt % of a white metal oxide pigment dispersed by two co-dispersants. The metal oxide pigment can have an average particulate size from 100 nm to 1 μm, and the co-dispersants can include both i) a short-chain anionic dispersant having a weight average molecular weight ranging from 1,000 Mw to 30,000 Mw, and ii) a non-ionic or predominantly non-ionic dispersant.

An ink jet recording method is provided for recording an image by ejecting an ink from a recording head including a member defining an ejection orifice through which the ink is ejected, an ejection element configured to generate an energy used for ejecting the ink, and a first flow path communicating with a portion between the ejection orifice and the ejection element. The method includes ejecting an ink through the ejection orifice, and moving the ink from the first flow path to the portion between the ejection orifice and the ejection element separately from the ejecting of the ink. In this method, the ink is an aqueous ink containing a coloring material and a compound containing a chain hydrocarbon having a carbon number of 8 or more to 18 or less substituted by a hydroxy group or an anionic group.