An expandable thermoplastic resin particle including a polymer obtained by a process including polymerizing monomers including 60 to 80 parts by weight of α-methylstyrene and 40 to 20 parts by weight of acrylonitrile. A content of residual monomeric components in the expandable thermoplastic resin particle is not more than 0.5% by weight. When an expanded mold article is produced from the expandable thermoplastic resin particle at an expansion ratio of 10 times, foam cells in a cross section of the expanded mold article have an average chord length of from 20 μm to 60 μm.

There are provided an aqueous pigment dispersion containing a pigment, hydrophilic fumed silica, and an aqueous medium; an ink jet recording ink containing such an aqueous pigment dispersion; and a printed article using the aqueous pigment dispersion. The average particle size of the hydrophilic fumed silica is preferably not more than 250 nm. The amount of the hydrophilic fumed silica is preferably in the range of 20 to 300 mass % relative to the amount of the pigment. The amount of the pigment is preferably in the range of 0.5 to 30 mass % relative to the amount of the whole aqueous pigment dispersion.

An aqueous organic pigment dispersion contains a green copper phthalocyanine pigment and an azo-coupled β-ketoamide pigment. It also includes an organic pigment dispersant at 40 weight % to 100 weight %, based on the sum of the weights of the organic pigments. This aqueous organic pigment dispersion can be combined with a humectant to provide an aqueous green inkjet ink composition. The weight ratio of the green copper phthalocyanine pigment to the azo-coupled β-ketoamide pigment is from 1:1 to 10:1. The median particle diameter of each of the green copper phthalocyanine pigment and the azo-coupled β-ketoamide pigment is less than 85 nm. At least 95% of the total particles of each of the green copper phthalocyanine pigment and the azo-coupled β-ketoamide pigment have a particle diameter of less than 150 nm. The aqueous green inkjet ink compositions can be used in various inkjet printing methods.

The present invention provides the following process for producing a fine organic pigment which is capable of producing the fine organic pigment that has a very small primary particle size and is excellent in filtering property even in a cleaning step, and a fine organic pigment produced by the process; a process for producing a dispersion using the fine organic pigment, and a dispersion produced by the process; and a process for producing an ink using the dispersion. The present invention relates to [1] a process for producing a fine organic pigment, including steps 1 and 2: step 1: kneading a mixture prepared by compounding a raw material organic pigment, a water-soluble inorganic salt, a water-soluble organic solvent and a compound represented by the following formula (1) with each other, the compound being compounded in an amount of not less than 0.8 part by mass and not more than 18.0 parts by mass on the basis of 100 parts by mass of the raw material organic pigment: R.sup.1O(PO).sub.m(EO).sub.nA (1); and step 2: subjecting the mixture obtained in the step 1 to cleaning treatment with an aqueous solvent and then to filtration, [2] a fine organic pigment produced by the process according to the above aspect [1], [3] a dispersion produced using the fine organic pigment according to the above aspect [2], [4] a process for producing a paste of a fine organic pigment, including the above step 1 and 2, [5] a process for producing a dispersion, including step 3 of subjecting the paste of the fine organic pigment produced by the process according to the above aspect [4], an organic solvent and water to dispersing treatment, and [6] a process for producing an ink, including step 4 of mixing the dispersion produced by the process according to the above aspect [5] with at least one material selected from the group consisting of water and an organic solvent.

An anti-corrosion pigment for use in an aqueous-based coating composition is provided herein. The anti-corrosion pigment disclosed comprises a plurality of titanium dioxide particles; in the range of from about 0.05% by weight to about 1% by weight, based on the total weight of the pigment, of at least one non-volatile, organic hydroxyl amine deposited on the surfaces of the titanium dioxide particles; and in the range of from about 0.02% by weight to about 1% by weight, based on the total weight of the pigment, of at least one organic dispersant deposited on the surfaces of the titanium dioxide particles. The pigment is in dry form. An aqueous-based coating composition, a method of forming a dry anti-corrosion pigment for use in an aqueous-based coating composition, and a method of forming an aqueous-based coating composition are also provided.

The novel yellow metal azo pigments based on at least three metal azo compounds, which differ at least in the type of metal, have improved colour strengths and are of excellent suitability for pigmentation of pigment preparations for a broad field of use.

The novel yellow metal azo pigments based on at least three metal azo compounds which differ at least in the type of metal have improved colour strengths and are of excellent suitability for pigmentation of pigment preparations for a broad field of use.

The novel yellow metal azo pigments based on at least three metal azo compounds which differ at least in the type of metal have improved colour strengths and are of excellent suitability for pigmentation of pigment preparations for a broad field of use.

The novel yellow metal azo pigments based on at least two metal azo compounds which differ a least in the type of metal have improved colour strengths and are of excellent suitability for pigmentation of pigment preparations for a broad field of use.

The present invention relates to a kit of parts comprising a dental mill blank comprising a porous zirconia material and a colouring solution for colouring the porous zirconia material. The porous zirconia material comprises Zr oxide calculated as ZrO2: from 80 to 97 wt.-%, Al oxide calculated as Al2O3: from 0 to 0.15 wt.-%, Y oxide calculated as Y2O3: from 1 to 10 wt.-%, Bi oxide calculated as Bi2O3: from 0.01 to 0.2 wt.-%, the porous zirconia material not comprising Fe calculated as Fe2O3 in an amount of more than 0.01 wt.-%, wt.-% with respect to the weight of the porous zirconia material. The colouring solution comprises solvent(s), colouring agent(s) comprising metal ions selected from Tb, Er, Pr, Mn or combinations thereof, the solution not comprising Fe ions in an amount of more than 0.01 wt.-%, the solution not comprising Bi ions in an amount of more than 0.01 wt.-%, wt.-% with respect to the weight of the colouring solution. The invention also relates to a process of producing a dental restoration, the process comprising the steps: providing a dental mill blank comprising a porous zirconia material as described in any of the preceding claims, machining an article out of the porous zirconia material, the article having the shape of a dental restoration with an outer and inner surface, providing a colouring solution as described in any of the preceding claims, applying the colouring solution to at least portions of the surface of the article having the shape of a dental restoration.