Nippon Shokubai Co., Ltd.

Seiko Epson Corporation

Oji Paper Co., Ltd.

Teruo Kikuta

Mitsuo Kushino

Atsushi Miyazaki

Makoto Matsumoto

Akio Ito

Masatoshi Yoshida

Masuji Izubayashi

Toshiaki Matsunaga

Shiro Nakano

Hidetoshi Hatta

Kohei Hori

Toshifumi Nishida

Katsuyuki Kono

Toshiki Nikaya

Yoshifumi Fukushima

An electrophoretic particle including: a pigment particle having an average particle diameter of 1 &#x3bc;m or smaller; and a polymer layer having an average thickness of 1 to 500 nm formed on a surface of the pigment particle, wherein 50% or higher of an entire surface of the pigment particle is coated with the polymer layer. The electrophoretic particle can be produced by radical polymerization using a polymerization initiator in a state where a pigment particle and monomer components are present in a solvent. The electrophoretic particle can be used in a microcapsule and a sheet for electrophoretic display, as well as an electrophoretic display device and an electronic equipment.

Electrophoretic particle, process for its production, and its use

An object of the present invention is to provide a microcapsule for an electrophoretic display device which can suppress reduction in later contrast even when the electrophoretic display device is allowed to stand under the high temperature and high humidity condition, favorably, under the high temperature and high humidity condition for a long time (e.g. under 60&#xb0; C., 90% RH for 24 hours). As a means of achieving this object, a microcapsule according to the present invention for an electrophoretic display device comprises an electrophoretic fine particle and a solvent both of which are encapsulated in a shell, and is characterized in that an amount of an alkaline metal ion in the whole microcapsule is 150 ppm or smaller.

Microcapsule for electrophoretic display device, process for manufacturing the same and use thereof

An aqueous resin dispersion for a heat-sensitive recording material is disclosed. The aqueous resin dispersion is obtained by the use of polyvinyl alcohol as an emulsifier and the use of two steps of polymerization. In the first step of polymerization, a polymeric monomer composition A is polymerized, composition A containing polymeric multi-functional monomers which constitute 15% by weight or more of the total weight of the polymeric monomers used for the first step. And, in the second step, a polymeric monomer composition B is polymerized, The invention also discloses a heat-sensitive recording material using such an aqueous resin dispersion as a color-developing layer or a protective coating.

Aqueous resin dispersion for heat-sensitive recording material and

A highly weather-resistant, single package, cross-linkable emulsion using an emulsion polymer (X) obtained by emulsion polymerization, in an aqueous medium, of polymerizable monomer ingredients (II) comprising (a) from 0.1 to 10% by weight of a polymerizable UV-ray stable monomer, (b) from 5 to 99.4% by weight of cycloalkyl group-containing polymerizable monomer, (c) from 0.5 to 40% by weight of a polymerizable monomer which contains the groups having reactivity with carboxyl groups and (d) from 0 to 94.4% by weight of other polymerizable monomer, in which the amount of the polymerizable monomers (a), (b), (c) and (d) in total is 100% by weight, by using a water soluble or water dispersible polymer (I) having a terminal alkyl group with an acid value of 200 or greater obtained by polymerizing a polymerizable monomer ingredient (A) containing an unsaturated carboxylic acid as an essential ingredient under the presence of an alkyl mercaptan of 6 to 18 carbon atoms. This emulsion provides a highly weather-resistant, single package, crosslinkable emulsion capable of forming a coating layer which rapidly dries to cure at the initial stage of coating, exhibits long lasting excellent water proofness and weather-resistance, and further, having satisfactory gloss retainability, shape retainability, chemical resistance, solvent resistance and so on.

Highly weather-resistant, single package, crosslinkable emulsion

The present invention yields a coating film excellent in adhesion, water resistance, solvent resistance and durability. A compound having a carboxyl group and a long-chain alkylthio group or a salt thereof is used as an emulsifier and emulsion polymerization is carried out using a polymerizable monomer or monomers having, within their molecule, a group reactive with a carboxyl group as raw materials for emulsion polymerization, whereby the resin produced by emulsion polymerization and the emulsifier react with each other efficiently on the occasion of film formation and form a crosslinked structure. When a compound having a polymerizable unsaturated group in addition to the carboxyl group and long-chain alkylthio group or a salt thereof is used as the emulsifier, not only the above-mentioned crosslinked structure is formed but also the polymerizable unsaturated group in the emulsifier will react with the unsaturated group in the polymerizable monomer or monomers in the manner of grafting. As a result, the compatibility between the emulsifier and the emulsion-polymerized resin is improved.

Aqueous crosslinkable resin dispersions, method of their production and

A compound having a carboxy group and a long-chain alkylthio group and/or a salt thereof is used as an emulsifier and, on the other hand, emulsion polymerization is carried out using a polymerizable monomer or monomers having, within their molecule, a group reactive with a carboxyl group as raw materials for emulsion polymerization, whereby the resin produced by emulsion polymerization and the emulsifier react with each other efficiently on the occasion of film formation and form a crosslinked structure. When a compound having a polymerizable unsaturated group in addition to the carboxyl group and long-chain alkylthio group and/or a salt thereof is used as the emulsifier, not only the above-mentioned crosslinked structure is formed but also the polymerizable unsaturated group in the emulsifier will react with the unsaturated group in the polymerizable monomer or monomers in the manner of grafting. As a result, the compatibility between the emulsifier and the emulsion-polymerized resin is improved.

Heat-sensitive recording paper having an overcoat layer formed from an

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Nagaokakyo, Japan

Teruo Kikuta