Nippon Paint Compnay, Ltd.

Tsuyoshi Imamura

Keizou Ishii

Koichi Saito

Shinichi Ishikura

Yasuhiro Shibai

Naoya Yabuuchi

Katsumi Mizuguchi

Yasuhiro Shibata

Manabu Yoshioka

Shuhei Yamoto

Masanori Ohiwa

Kunihiko Takeuchi

Katsuhiko Sho

Takahiro Mukae

Yashuhiro Shibai

Toner particles having a polar group of either an acid group or a basic group at least on surface layers thereof are employed, and a polymer, which contains a polar group of reverse polarity to the polar group of the surface layers of the toner particles and is soluble in a medium, is added to the medium.

Liquid developer

An aqueous coating composition comprising: (A) 10 to 95% by weight (based on solid content) of a film forming polymer which is prepared by neutralizing at least a part of acid groups contained in a copolymer having a number average molecular weight ranging from 6,000 to 50,000 prepared by copolymerizing (A1) 5 to 40% by weight of an amide group-containing ethylenically unsaturated monomer, (A2) 3 to 15% by weight of an acid group-containing ethylenically unsaturated monomer, (A3) 10 to 40% by weight of a hydroxyl group-containing ethylenically unsaturated monomer, and (A4) a remainder amount of ethylenically unsaturated monomers other than the monomers (A1) to (A3); and (B) 5 to 90% by weight (based on solid content) of an aqueous dispersion of carboxyl group-containing acrylic resin particles having a particle size ranging from 0.01 to 1.0 .mu.m and an acid value ranging from 20 to 80. An aqueous metallic-base coating composition which enables to form a coating film of an improved appearance at a high workability almost free from 'sagging' and 'unevenness' is provided.

Aqueous coating composition

A method of preparing microcapsules includes the steps of preparing a block polymer having a block of a hydrophobic repeating unit and a block of a hydrophilic repeating unit, and employing the block polymer as a protective colloid for preparing microcapsules in a nonaqueous medium by interfacial polymerization.

Method of preparing microcapsules

Disclosed are aqueous crosslinked polymer particles which provide excellent properties and paint workability. Aqueous crosslinked polymer particles have 20 to 200 nm of an average particle size (De), measured by a transmission electron microscope after dyeing with uranyl acetate, and also have 0.5 to 0.9 of an average roundness (R) represented by the equation:

Aqueous crosslinked polymer particles and their production

Polymer particles having a small particle diameter and a narrow particle diameter distribution are obtained by a continuous polymerization method which does not accompany an increase of cohering products attaching to an inner face of a reaction vessel and an air-bubble invasion and, in which stirring of a material solution for polymerization is easy. An emulsion polymerization reaction or a suspension polymerization reaction is carried out by supplying a material solution for polymerization continuously to a clearance between coaxial double cylinders, which have stretched toward a direction crossing a horizontal plane, from the end side of the cylinders, by rotating at least one of the double cylinders round the axis and thereby, causing Taylor vortices. The polymer particles thus-formed are obtained by through from the other end side of the double cylinders to the outside.

Continuous polymerization method and apparatus

Polymer particles having a small particle diameter and a narrow particle diameter distribution are obtained by a continuous polymerization method which does not accompany an increase of cohering products attaching to an inner face of a reaction vessel and an air-bubble invasion and, in which stirring of a material solution for polymerization is easy. An emulsion polymerization reaction or a suspension polymerization reaction is carried out by supplying a material solution for polymerization continuously to a clearance between coaxial double cylinders, which have stretched toward a direction crossing a horizontal plane, from the end side of the cylinders, by rotating at least one of the double cylinders round the axis and thereby, causing Taylor vortices. The polymer particles thus-formed are obtained by through the other end side of the double cylinders to the outside.

Growing community of inventors

Katano, Japan

Tsuyoshi Imamura