Matsumoto Yushi-Seiyaku Co., Ltd.

Shiseido Company, Limited

Yasuyuki Nomura

Katsushi Miki

Tetsuya Kanemaru

Ken Shoji

Naoya Tayagaki

Koichi Sakabe

Sumie Taguchi

Tomonori Toyoda

Hiroaki Shigeta

Heat-expandable microspheres having an almost spherical shape and high expansion performance and exhibiting good workability when mixed with a resin, a process for producing the heat-expandable microspheres, and applications thereof. The heat-expandable microspheres include a thermoplastic resin shell and a blowing agent encapsulated therein and vaporizable by heating. The thermoplastic resin is produced by polymerizing a polymerizable component containing a methacrylate monomer and a carboxyl-containing monomer, and optionally containing a nitrile monomer in an amount ranging from 0 to 30 parts by weight to 100 parts by weight of the total amount of the methacrylate monomer and the carboxyl-containing monomer. The blowing agent contains a hydrocarbon having at least 8 carbon atoms per molecule.

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

Heat-expandable microspheres with high encapsulation efficiency of a blowing agent and good heat-expansion performance, a process for reproducibly producing the heat-expandable microspheres and application thereof are provided. The heat-expandable microspheres comprise essentially a thermoplastic resin shell and a blowing agent encapsulated therein, and contain not more than 500 ppm of silicon, not more than 350 ppm of aluminum and not more than 600 ppm of the total of the silicon and aluminum. The heat-expandable microspheres retain at least 70% of the blowing agent encapsulated therein at the temperature which is the average of their expansion-initiation temperature and maximum expansion temperature.

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

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Yao, Japan

Yasuyuki Nomura