Matsumoto Yushi-seiyaku Co., Ltd.

The Yokohama Rubber Co., Ltd.

Yoshiaki Shirakabe

Toshiaki Masuda

Kenichi Kitano

Katsushi Miki

Ichiro Takahara

Naoki Kushida

Takeshi Inohara

Ikuo Yosejima

Makio Mori

Takamasa Kitamura

Takashi Hujie

Heat-expandable microspheres include a shell of thermoplastic resin and core material encapsulated in the shell. The core material include a blowing agent having a boiling point not higher than the softening point of the thermoplastic resin and a gas migration inhibitor having a boiling point higher than the softening point of the thermoplastic resin. The ratio of the gas migration inhibitor to the core material is at least 1 weight percent and below 30 weight percent. The average particle size of the heat-expandable microspheres ranges from 1 to 100 micrometers.

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

A rubber composition for a tire containing (i) 100 parts by weight of a diene-based rubber and (ii) 0.5 to 25 parts by weight of a heat-expandable microcapsule including a shell, and a substance capable of vaporizing or expanding under heating to thereby generate a gas and a nonpolar oil, both encapsulated in the shell,

Rubber composition for tire

Thermo-expansive microcapsules comprising a shell of a polymer produced by polymerizing a mixture of monomers, which comprises (I) a nitrile monomer, (II) a monomer having an unsaturated double bond and carboxyl groups in a molecule, (III) a monomer having two or more of polymerizable double bonds in a molecule, and optionally, (IV) a monomer different from and copolymerizable with the monomers (I), (II) and (III) and a blowing agent encapsulated in the shell. The volume retention of the expanded microcapsules of the thermo-expansive microcapsules is 50% or more after loaded with 15 MPa.

Thermo-expansive microcapsules and their application

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Yao, Japan

Yoshiaki Shirakabe