Nippon Paint Compnay, Ltd.

Haruhiko Sato

Yutaka Harada

Takehiro Ojima

Yasuhiko Nakae

Atsushi Yamada

Shinji Seo

Masami Yabuta

Kazuhiko Nishimura

Akio Kashihara

Naoya Yabuuchi

Akihiro Kanakura

Katsuaki Kida

A thermosetting powder coating composition prepared by a wet process, which contains a mixture comprising (a) an epoxy-containing acrylic resin, (b) a polycarboxylic acid compound curing agent, (c) fine crosslinked resin particles and, optionally, (d) a resin that exists in the liquid form at room temperature.

Powder coating of epoxy-acrylic resin, polycarboxylic acid and crosslinked resin particles

A thermosetting powder coating composition prepared by a wet process, which contains a mixture comprising (a) an epoxy-containing acrylic resin, (b) a polycarboxylic acid compound curing agent, (c) fine crosslinked resin particles and/or (d) a resin that exists in the liquid form at room temperature.

Powder coating of epoxy-acrylic resin, polycarboxylic acid, crosslinked particles and liquid resin

Thermoplastic or thermosetting resin particles having a narrow particle size distribution are produced by suspending a liquid resinous composition in an aqueous solution of an anionic or cationic polyelectrolyte as primary particles of oil droplets, adjustion the suspension at a pH at which the polyelectrolyte is insolubilized to agglomerate into secondary particles of larger particle size, and allowing the secondary particles in the suspension to solidify.

Process for manufacturing resin particles having narrow particle size

A process for manufacturing thermosetting resin particles for powder coating use exhibiting improved anti-blocking property and workability is disclosed. The process include providing a suspension of the thermosetting resin particles in an aqueous medium and an emulsion or dispersion of a vinyl-based polymer having a relatively high Tg, respectively. The thermosetting resin particles are then treated with the emulsion while the resin particles are still suspended in or wetted with the aqueous medium to adhere the vinyl based polymer onto the resin particles forming a shell layer. The resin particles are dried and made to ready to use in the powder coating.

Process for manufacturing thermosetting resin particles for powder

Thermosetting resin particles having a narrow particle size distribution useful for powder coating application are produced by the steps of (a) providing a first water-soluble polymer having a cloud point within the range between 30.degree. C. and 90.degree. C. and a second water-soluble polymer not having any cloud point; (b) preparing an aqueous suspension in which an organic solvent-containing, liquid thermosetting resin composition is suspended as primary particles of oil droplets in an aqueous suspension medium containing the first and second water-soluble polymers, (c) heating the suspension to a temperature higher than the cloudy point to allow the oil droplets to agglomerate into secondary particles of larger particle sizes, (d) removing the organic solvent contained in the particles during or after step (c) and optionally (e) recovering the particles.

Process for manufacturing thermosetting resin particles

Disclosed is a preparation method of a toner comprising steps of:

Production of toner

The present invention provides a method which makes it possible to manufacture substantially spherical resin granules with a narrow grain size distribution by a simple operation. According to the present invention, there is provided a method of manufacturing resin granules with a grain diameter of 1.about.100 .mu.m and narrow grain size distribution by controlling the cloud point of polyvinyl alcohol and other water soluble polymers.

Manufacturing method of resin granules

Dry toner for electrophotography in the form of colored particles, each particle being composed of a colored core portion having an average diameter of 5 to 20.mu. and comprising as main ingredients, a coloring material and heat-meltable resin having a flow initiation temperature of 120.degree. C. to 160.degree. C., and a covering shell portion of a vinyl resin mixture of a comparatively low molecular weight component and a high molecular weight component, each having the maximum value in the molecular weight distribution curve obtained by gel-permeation chromatography of 8.times.10.sup.3 to 3.times.10.sup.4 and 8.times.10.sup.4 to 5.times.10.sup.5, respectively, and present in a ratio of Mw/Mn=5.0 or more; the weight ratio of said vinyl resins to the total weight of said core and shell portions being 8 to 25% by weight. The present dry toner is particularly useful for use in a high speed electrography.

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Hirakata, Japan

Haruhiko Sato