Patents by Inventor Akio Iakashima

Akio Iakashima has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Rubber composition comprising a styrene-butadiene block copolymer having two kinds of blocks
    Patent number: 4782119
    Abstract: A rubber composition containing at least 20% by weight of a styrene-butadiene block copolymer consisting of a block (A) and a block (B) characterized in that: (i) the block (A) is a styrene-butadiene copolymer block having the content of styrene of 10-80% by weight and the average content of the vinyl bonds in the butadiene portion of 30-70% by weight; (ii) the block (B) is a polybutadiene block with the average content of the vinyl bonds in the butadiene portion being not more than 60% by weight (iii) the styrene-butadiene block copolymer contains at least 20% by weight of each of the block (A) and the block (B); (iv) the average content of the vinyl bonds in the butadiene portion of the block (A) is greater by at least 5% by weight than that of the block (B); (v) the glass transition temperature of the block (A) is higher by at least 30.degree. C.
    Type: Grant
    Filed: August 27, 1985
    Date of Patent: November 1, 1988
    Assignees: Japan Synthetic Rubber Co., Ltd., Bridgestone Corporation
    Inventors: Fumio Tsutsumi, Akio Iakashima, Mitsuhiko Sakakibara, Noboru Oshima, Tatsuo Fujimaki, Yoshiyuki Morimoto