The present application relates to the field of black coloring of materials made from wood, such as reconstituted wood panels or paper/cardboard. The black coloring composition for wood-based materials includes a black pigment, a reactive type black dye and water. It is also possible to prepare a dry extract for some special applications.

The present invention provides a pigment dispersant: that is capable of remarkably ameliorating fluidity of a liquid product, such as an ink or a paint, which contains particles of a pigment, such as a black azo pigment, in a dispersed state; that can suppress aggregation of piment particles; that prevents occurrence of foreign substances; and that is capable of producing a colored article excellent in optical density. Provided is a pigment dispersant being a compound represented by the following formula (1).

##STR00001##

wherein R.sub.1 and R.sub.2 each independently represent a group obtained by eliminating one hydrogen atom from an amino group of an amine compound containing a basic nitrogen atom, and R.sub.3 and R.sub.4 each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a hydroxy group.

The present invention provides an aqueous pigment-material solution which has excellent thermal stability and less fading particularly even under an acidic condition, a method for producing the same, and a blue-colored beverage. Provided are an aqueous pigment-material solution including a pigment material containing 20 mmol to 200 mmol of polycarboxylic acid having one or more hydroxy groups, in terms of carboxylic acid equivalent, per 1 g of phycocyanin, in which when both the phycocyanin and the polycarboxylic acid are added such that a color value represented by absorbance at 620 nm is 2.5 to 5, an optical density per 1 cm of an optical path length at 800 nm is 0.05 or lower at a hydrogen ion concentration (pH) of 3 or lower, a method for producing the aqueous pigment-material solution, and a blue-colored beverage.

An object of the present invention is to provide a technique of suppressing precipitation of an anthocyanin pigment in a range other than the highly acidic range. The present invention provides an anthocyanin pigment preparation, comprising: an anthocyanin pigment; and an emulsifier, wherein the pH when the anthocyanin pigment preparation is diluted with water or dissolved in water so that a color value becomes 10 is more than 3.

The present invention relates to [1] a process for producing a pigment composition, including the step of subjecting a raw material pigment composition containing PY74 and a specific by-product to a treatment with an oxidizing agent, in which a content of the specific by-product in the pigment composition after the treatment on the basis of a content of PY74 in the pigment composition after the treatment is not more than 1,200 mg/kg; [2] a process for producing a pigment composition, including the step of subjecting a raw material pigment composition containing PY74, a specific by-product and water to a treatment with hydrogen peroxide; [3] a method of reducing a content of a specific by-product in a raw material pigment composition containing PY74 and the specific by-product, said method including the step of subjecting the raw material pigment composition to a treatment with an oxidizing agent; and [4] a method of preventing an ink for ink-jet printing from suffering from ejection defects, including the step of compounding the pigment composition produced by any of the aforementioned processes in the ink for ink-jet printing.

A method for determining hydration of a polymer includes mixing a water-soluble, powdered dye with a powdered polymer and introducing the mixed water-soluble, powdered dye and powdered polymer into a water-based fluid. Full hydration of the powdered polymer is determined when the mixed water-soluble, powdered dye, powdered polymer and water-based fluid comprises substantially no internal optical contrast.

A textile printing ink jet ink composition includes a dioxazine pigment, a resin particle, and a lubricant, wherein the content of the dioxazine pigment is 0.5 to 1.5 mass % based on the total amount of the ink composition.

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 % quinacridone pigment, from 0.5 wt % to 3.5 wt % styrene-acrylic dispersant, and from 0.5 wt % to 3.5 wt % hydrophilic polyurethane dispersant having an acid number from 20 to 100. The styrene-acrylic dispersant and the hydrophilic polyurethane dispersant can be present at a weight ratio from 1:5 to 5:1.

A method for determining hydration of a polymer includes mixing a water-soluble, powdered dye with a powdered polymer and introducing the mixed water-soluble, powdered dye and powdered polymer into a water-based fluid. Full hydration of the powdered polymer is determined when the mixed water-soluble, powdered dye, powdered polymer and water-based fluid comprises substantially no internal optical contrast.

Novel, nano-structured particles are formed by introducing a selected solid of interest into a structured fluid matrix formed by a dispersion of a small molecule host vessel components, such as a native or modified polysaccharide, cavitand, simple sugar, disaccharide, simple polyol or other similarly structured molecule known to be useful as a host vessel, in an acidic medium or other solvent, whereby the particle size of the introduced solid is reduced and or limited in the structured fluid matrix, by incorporation into or attachment to, the host vessel. The simple, one-batch mixing process results in stabilized colloidal dispersions of the nanoparticles of a variety of solids of varying scope and function and useful in a wide variety of applications, including without limitation ceramic materials, such as hexagonal boron nitride.