Kao Corporation

Mitsubishi Chemical Corporation

Tomohide Yoshida

Kosuke Muto

Hiroshi Nakano

Eiji Shirai

Yasufumi Ueda

Shoichi Murata

Hiroyuki Kaneko

Tarou Amano

Hirotaka Takeno

Manabu Suzuki

Norihiro Hirai

Motomu Shibata

Hiroto Hayashi

Takashi Kanno

The present invention relates to [1] a process for producing a metal fine particle dispersion containing metal fine particles (a) dispersed with a polymer B, including the step 1 of mixing a metal oxide A, the polymer B and a compound C with each other, in which the polymer B contains a hydrophilic group; the compound C is a dihydric alcohol represented by the general formula (1); and the metal fine particles (a) have a cumulant average particle size of not more than 50 nm, and [2] an ink containing the metal line particle dispersion obtained by the production process described in the above [1].

Fine metal particle dispersion production method

The present invention relates to a method for producing an electrically conductive member which includes the step of applying an electrically conductive ink containing a metal fine particle dispersion to a substrate to form electrically conductive images on the substrate under ordinary-temperature environments, thereby obtaining the electrically conductive member, in which the metal fine particle dispersion contains metal fine particles (a) dispersed therein with a polymer B; a glass transition temperature of the polymer B is not higher than a temperature at which the electrically conductive images are formed on the substrate; and the substrate has a porous surface.

Method for manufacturing electrically conductive member

A metal fine particle-containing ink that contains metal fine particles dispersed therein with a polymer dispersant, a low-molecular weight carboxylic acid and an aqueous solvent, wherein the polymer dispersant contains a constitutional unit derived from an acid group-containing monomer; a content of the low-molecular weight carboxylic acid C in the ink is not less than 1% by mass and not more than 15% by mass. A boiling point (C) of the low-molecular weight carboxylic acid and a boiling point (D) of the aqueous solvent satisfy the following relational formula (I); and an acid dissociation exponent pKa (C) of the low-molecular weight carboxylic acid and an acid dissociation exponent pKa (B) of an acid group in the polymer dispersant satisfy the following relational formula (II):boiling point ()>boiling point ()   (I), andpKa ()<pKa ()   (II).

Ink containing fine metal particles

The present invention relates to a metal fine particle-containing ink containing metal fine particles (a) dispersed therein with a polymer B, in which the ink contains an ink solvent S; a difference ΔSP (|SP(S)−SP(B)|) between solubility parameters of the solvent S and the polymer B is not more than 1.5 (cal/cm)wherein SP(S) and SP(B) are a solubility parameter of the ink solvent S and a solubility parameter of the polymer B, respectively, as measured by a Fedors method; and the SP(B) is not less than 9.5 (cal/cm)and not more than 10.5 (cal/cm), as well as a method for producing a printed material, which includes the step of applying the metal fine particle-containing ink to a printing substrate to form a metal coating film of the ink on the printing substrate under ordinary-temperature environments, thereby obtaining the printed material.

Metal-microparticle-containing ink

The present invention relates to a process for producing a dispersion of white fine particles from which a white ink that is capable of exhibiting excellent hiding power, rub fastness and water resistance even when printed on a low-water absorbing printing medium can be obtained by incorporating the dispersion of the white fine particles into the ink, and a water-based ink for ink-jet printing which contains the white fine particles. The present invention provides [1] a process for producing a dispersion of white fine particles, including step 1 of mixing titanium oxide and a polymer dispersant at a pH value that is not less than an acid dissociation exponent (pKa) of at least a part of an acid component of the polymer dispersant to thereby obtain a titanium oxide dispersion, in which an isoelectric point (A) of the titanium oxide and the acid dissociation exponent (pKa) (B) of the polymer dispersant satisfy a relationship represented by the formula: A&#x2212;B&#x2265;0, the polymer dispersant contains a constitutional unit derived from a hydrophobic monomer, and a volume median particle size (D) of particles in the titanium oxide dispersion is from 150 to 500 nm; and step 2 of adding a polymerizable monomer to the titanium oxide dispersion obtained in the step 1 to subject the polymerizable monomer to polymerization reaction, thereby obtaining the dispersion of the white fine particles, and [2] a water-based ink for ink-jet printing which contains the white fine particles obtained above.

Method for manufacturing white fine particle dispersion

The present invention relates to white fine particles from which a white ink that is capable of satisfying both of high hiding power and good bending resistance in a printed material can be obtained, and further relates to white fine particles from which an ink that is capable of satisfying not only excellent fixing properties even when printed on a non-liquid absorbing printing medium such as a resin film, but also suppression of increase in viscosity of the ink and at the same time good deinking properties at a high level can be obtained. The present invention provides [1] white fine particles containing titanium oxide and a polymer component with which the titanium oxide is encapsulated, in which a titanium atomic fraction of a surface of the respective white fine particles as measured at a photoelectron takeoff angle of 45&#xb0; by X-ray photoelectron spectroscopy (XPS) is not more than 7 atomic %, [2] a water-based ink containing the aforementioned white fine particles, in which the titanium atomic fraction of the surface of the respective white fine particles as measured at a photoelectron takeoff angle of 45&#xb0; by XPS is not more than 5 atomic %, and [3] a process for producing a dispersion of white fine particles, including step 1 of mixing titanium oxide and a polymer dispersant to obtain a titanium oxide dispersion and step 2 of adding a polymerizable monomer to the thus obtained titanium oxide dispersion to subject the polymerizable monomer to polymerization reaction, thereby obtaining the dispersion of the white fine particles, in which a titanium atomic fraction of a surface of the respective white fine particles as measured at a photoelectron takeoff angle of 45&#xb0; by XPS is not more than 7 atomic %.

Fine white particles comprising polymer-encapsulated titanium oxide

The present invention relates to a binder resin composition for toners for development of electrostatic images capable of giving a toner excellent in fusing properties on PP films, a toner for development of electrostatic images containing the binder resin composition, a printing method using the toner, and a printed material. [1] A binder resin composition for toners for development of electrostatic images, including a polyester-based resin and polyolefin particles, wherein the polyolefin particles contain a polymer having a polymer skeleton of olefin having 2 or more and 3 or less carbon atoms, the volume median diameter (D) of a small particle size component, as measured according to a dynamic light scattering method using a dispersion S of a small particle size component obtainable according to Methods 1 and 2, is 20 nm or more and 400 nm or less, the content of a large particle size component obtainable according to Method 2 is 0% by mass or more and 30% by mass or less relative to the total amount of the large particle size component and the small particle size component, and the content of the small particle size component is 70% by mass or more and 100% by mass or less relative to the total amount of the large particle size component and the small particle size component, and the melting endothermic energy amount of the small particle size component is 3 J/g or more and 10 J/g or less; [2] a toner for development of electrostatic images including the binder resin composition for toners for development of electrostatic images according to the above [1] in an amount of 20% by mass or more and 100% by mass or less in the binder resin therein, and including a releasing agent having a melting point of 60&#xb0; C. or higher and 100&#xb0; C. or lower in an amount of 1 part by mass or more and 10 parts by mass or less relative to 100 parts by mass of the binder resin; [3] a printing method including printing on a plastic film according to an electrophotographic method with the toner for development of electrostatic images according to the above [2]; and [4] a printed material obtainable according to the method of the above [3].

Binder resin composition for electrostatic image developing toners

The present invention provides a toner for development of electrostatic images including a polyester-based resin and a polypropylene-based wax, which is excellent in fusing properties on a polypropylene film. The present invention relates to [1] a resin binder composition for toners for development of electrostatic images which has an endothermic amount ratio &#x394;Hof not less than 0.10 and not more than 0.80, [2] a resin binder composition for toners for development of electrostatic images in which a volume-median particle size (D) of a wax as a whole contained therein is not less than 1 &#x3bc;m and not more than 50 &#x3bc;m; a volume-median particle size (D) of a small particle size component of the wax is not less than 20 nm and not more than 400 nm; and a content of the small particle size component in the wax is not less than 20% by mass and not more than 90% by mass, [3] a process for producing a resin binder composition for toners for development of electrostatic images in which a polypropylene-based wax is added to a reaction system prior to addition polymerization upon production of a composite resin as a resin binder; and [4] a toner for development of electrostatic images including the resin binder composition as described in the above [1] or [2].

The present invention relates to a process for producing a toner for development of electrostatic images, including the following steps (1) to (3): Step (1): aggregating resin particles (X) containing a composite resin that contains a segment constituted of a polyester resin (a) obtained by polycondensing an alcohol component containing 80 mol % or more of a propyleneoxide adduct of bisphenol A and a polycarboxylic acid component, and a vinyl-based resin segment containing a constitutional unit derived from a styrene-based compound, in an aqueous medium, to obtain aggregated particles (1); Step (2): aggregating the aggregated particles (1) obtained in the step (1) with resin particles (Y) containing a polyester resin (b) obtained by polycondensing an alcohol component containing 80 mol % or more of an ethyleneoxide adduct of bisphenol A and a polycarboxylic acid component to obtain aggregated particles (2); and Step (3): coalescing the aggregated particles (2) obtained in the step (2).

Process for producing toner for development of electrostatic images

An object of the present invention is to provide a resin composition improved in film formability and/or mechanical property, particularly tensile elastic modulus or tearing strength, of the film. The present invention provides a resin composition including at least (A) an aliphatic polyester-based resin and (C) a starch, the aliphatic polyester-based resin (A) forming a matrix phase and the starch (C) forming a dispersed phase, wherein the average particle diameter of the dispersed phase is 1 &#x3bc;m or less.

Growing community of inventors

Wakayama, Japan

Tomohide Yoshida