Abstract: A problem to be solved by the present invention is to provide an aqueous pigment dispersion for adjustment of ink for ink jet recording in which the optical density OD of plain paper and the gloss value of photographic paper are compatible with each other at a high level. Another object of the present invention is to provide an ink for ink jet recording obtained by using the aqueous pigment dispersion. The present invention relates to an aqueous pigment dispersion including an aqueous medium, a dispersion (A), and a dispersion (B), wherein the dispersion (A) contains a pigment (a) and a pigment dispersant resin, and has a volume average particle diameter of 40 nm or more and less than 70 nm, and wherein the dispersion (B) contains a self-dispersing pigment (b), and has a volume average particle diameter of 70 nm or more and 210 nm or less.

Abstract: A highly efficient method is provided for producing a water-based ink for ink jet recording with which the number of coarse particles in a water-based pigment dispersion liquid is significantly reduced, dispersed particles are made finer, the dispersion stability is improved, the storage stability is improved, and high discharge stability is achieved when a water-based ink for ink jet recording is produced. Particularly, provided is a method for producing a water-based pigment dispersion liquid, the method including kneading a mixture containing a quinacridone type pigment (a), a styrene-acrylic acid type copolymer (c), a basic compound (d), and a polyoxyalkylene glycol or its derivative (e) to prepare a pigment dispersion that is solid at room temperature and mixing a aqueous medium and the pigment dispersion to decrease the viscosity and liquefy the pigment dispersion.

Abstract: A highly efficient method is provided for producing a water-based ink for ink jet recording with which the number of coarse particles in a water-based pigment dispersion liquid is significantly reduced, dispersed particles are made finer, the dispersion stability is improved, the storage stability is improved, and high discharge stability is achieved when a water-based ink for ink jet recording is produced. Particularly, provided is a method for producing a water-based pigment dispersion liquid, the method including kneading a mixture containing a quinacridone type pigment (a), a styrene-acrylic acid type copolymer (c), a basic compound (d), and a polyoxyalkylene glycol or its derivative (e) to prepare a pigment dispersion that is solid at room temperature and mixing a aqueous medium and the pigment dispersion to decrease the viscosity and liquefy the pigment dispersion.

Abstract: A pigment dispersion of the present invention includes a bisacetoacetarylide pigment (a); a styrene-acrylic acid-based copolymer (b); a basic compound (c); and a wetting agent (d), wherein the wetting agent (d) includes at least one diol compound (e), the diol compound (e) is selected from the group consisting of dipropylene glycol, 2-ethyl-1,3-hexanediol, and 1,2-hexanediol the mass ratio (e)/(a) of the diol compound (e) and the bisacetoacetarylide pigment (a) is within a range from 3/100 to 8/100.

Abstract: A pigment dispersion of the present invention includes a bisacetoacetarylide pigment (a); a styrene-acrylic acid-based copolymer (b); a basic compound (c); and a wetting agent (d), wherein the wetting agent (d) includes a diol compound (e), the diol compound (e) is a compound represented by a general formula (1) or a general formula (2), and A-B??(1) C—O-D??(2) the mass ratio (e)/(a) of the diol compound (e) and the bisacetoacetarylide pigment (a) is within a range from 3/100 to 15/100.

Abstract: An information processing apparatus is characterized in that firmware is easily replaced in the case where a booting operating system is changed for another to improve the operational efficiency associated with the changing of the operating system; plural pieces of firmware, each of which is compatible with each of plural operating systems of different kinds, types or versions, are stored in a storage unit and each piece of firmware is provided with compatible information indicating which of the operating systems each pieces of firmware conforms to; and the type or version of operating system to boot is determined when booting the operating system, and firmware compatible with compatible information is selected from the storage unit for replacement on the basis on a determination result.

Abstract: A thin film magnetic head includes a slider and a thin film magnetic transducing element, wherein the slider is provided with an insulating film on a surface of an electric conductive substrate, the thickness of the insulating film being in a range of 0.5 .mu.m-3 .mu.m, and the thin film magnetic transducing element is formed on the insulating film and has a thin film magnetic circuit including a magnetic film and a coil film.

Abstract: An improved composite magnetic recording head having a core chip with two opposed magnetic members via a magnetic gap and a nonmagnetic layer is disposed on at least one of the magnetic members and a thin magnetic layer is disposed on the non-magnetic layer. The thin magnetic layer has a higher saturation flux density than the magnetic members and the non-magnetic layer increases the adhesive strength between the thin magnetic layer and the magnetic member. The core chip fits into a slide member and is integrated using an adhesive glass.

Abstract: Treatment baths for surface treatment of semiconductor wafers by dipping thereof into a treatment liquid are arranged in a treatment bath train.One or more selected treatment baths among these treatment baths are constructed to have a plurality of unit treatment vessels. The treatment liquid in these treatment vessels is replaced successively one by one of the unit treatment vessels. The semiconductor wafers are dipped in the treatment liquid contained in that unit treatment vessel that is not being subjected at that moment to the replacement of the treatment liquid.

Abstract: Treatment baths for surface treatment of semiconductor wafers by dipping thereof into a treatment liquid are arranged in a treatment bath train.One or more selected treatment baths among these treatment baths are constructed to have a plurality of unit treatment vessels. The treatment liquid in these treatment vessels is replaced successively one by one of the unit treatment vessels. The semiconductor wafers are dipped in the treatment liquid contained in that unit treatment vessel that is not being subjected at that moment to the replacement of the treatment liquid.

Abstract: A polyurethane resin composition which comprises (1) a polyurethane prepolymer in the form of liquid or solution, (2) colloidal silica and (3) a siloxane compound having a polyoxyethylene chain in the molecule maintains an excellent thixotropy even after solvents and additives are added and kneaded as the case may be.

Abstract: A solid catalyst comprising (1) silver ion, (2) aluminum oxide and (3) silicon oxide, which may further comprise, as the fourth ingredient(s), the oxide and/or ion of one or more of transition elements, alkaline earth metals, boron, thallium, tin, lead and phosphorus gives a high yield of isoprene in the reaction of isobutylene and formaldehdye and has a prolonged catalytic activity.