Matsumoto Yushi-seiyaku Co., Ltd.

Satoshi Kawanami

Kenichi Kitano

Katsushi Miki

Toshiaki Masuda

Ichiro Takahara

Takeshi Inohara

Ikuo Yosejima

Takayuki Aoki

Daisuke Nakatomi

Takeyoshi Fukuda

Hiroki Naito

Yoshitsugu Sasaki

Heat-expandable microspheres having a thermoplastic resin shell and a thermally-vaporizable blowing agent encapsulated therein. The thermoplastic resin is a copolymer produced from a polymerizable component containing 15 to 90 wt % of acrylonitrile, 3 to 50 wt % of an acrylate ester monomer (A) represented by formula (1) shown below, and 3 to 70 wt % of a methacrylate ester monomer (B) represented by formula (2) shown below. The weight ratio of the acrylate ester monomer (A) represented by formula (1) to the methacrylate ester monomer (B) represented by formula (2) in the polymerizable component (A:B) ranges from 10:90 to 90:10:HC&#x2550;CH&#x2014;COOR&#x2003;&#x2003;(1)HC&#x2550;C(CH)&#x2014;COOR&#x2003;&#x2003;(2).Also disclosed are hollow particles manufactured by expanding the heat-expandable microspheres; a composition containing a base compound and the heat-expandable microspheres or the hollow particles; and a formed product manufactured by molding or applying the composition.

Heat-expandable microspheres and applications thereof

Heat-expandable microspheres having an expansion temperature which can be decreased by a simple means without changing the polymerizable monomer and its ratio and/or changing the blowing agent and its ratio, and applications thereof. The heat-expandable microspheres are composed of a thermoplastic resin shell and a core material encapsulated therein. The core material contains a thermally-vaporizable blowing agent which imparts a swelling degree of less than 5% as defined by the following formula (I) and a component (A) which imparts a swelling degree of 5 to 30% as defined by the following formula (I), wherein an amount of the component (A) ranges from 0.0001 to 30 parts by weight to 100 parts by weight of the blowing agent:Swelling degree (%)={()/}&#xd7;100&#x2003;&#x2003;(I)wherein Mand Mare as defined herein.

Heat-expandable microspheres and application thereof

Heat-expandable microspheres include a shell of thermoplastic resin and a blowing agent encapsulated therein having a boiling point not higher than the softening point of the thermoplastic resin, have a maximum expanding ratio not lower than 50 times, and are thermally expanded into hollow particulates having a repeated-compression durability not lower than 75 percent. The method of producing the heat-expandable microspheres includes the steps of dispersing an oily mixture containing a polymerizable component and the blowing agent in an aqueous dispersing medium containing a specific water-soluble compound and polymerizing the polymerizable component contained in the oily mixture.

Heat-expandable microspheres, method for producing the same, and application thereof

A production method for heat-expandable microspheres, which have high expanding ratio and are thermally expanded into hollow particulates having excellent repeated-compression durability, and application thereof are provided. The method produces heat-expandable microspheres a shell of thermoplastic resin and a blowing agent being encapsulated therein and having a boiling point not higher than the softening point of the thermoplastic resin.

Method for producing heat-expandable microspheres and application thereof

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Yao, Japan

Satoshi Kawanami