Nippon Steel Corporation

Toyo Boseki Kabushiki Kaisha

Hiroshi Endoh

Nobuo Kadowaki

Takeshi Yatsuka

Yoshimasa Zama

Masanori Nakamura

Hiroshi Hirakouchi

Yutaka Mizumura

Hiroshi Nagai

Takeshi Yatuka

There is disclosed a viscoelastic resin composition for vibration damping material containing as essential components a polyester resin having a molecular weight of 5,000 to 50,000 and an acid value of 50 to 500 equivalents/10.sup.6 g, at least 80 mol % of the polycarboxylic acid component of which is an aromatic dicarboxylic acid and, at least 30 mol % of the polyol component of which is a compound of the formula (I):

Viscoelastic resin composition or vibration damping material

Disclosed herein is a viscoelastic resin composition for vibration-damping material which comprises (A) at least one amorphous polyester resin of low specific gravity in which more than 40 mol % of the dibasic acid moiety is of aromatic type, (B) at least one amorphous polyester resin of high specific gravity in which more than 80 mol % of the dibasic acid moiety is of aromatic type, and (C) at least one hardener selected from the group consisting of polyisocyanate compounds, epoxy group-containing compounds, and acid anhydrides, said consitutents (A) and (B) being in the ratio of from 90:10 to 30:70 by weight and differing from each other in specific gravity (at 30.degree. C.) by 0.06 to 0.15 and also in molecular weight by more than 10000, with that of either of them being higher than 5000. This resin composition gives a vibration-damping material which exhibits improved vibration-damping properties, adhesive strength, formability, and heat resistance after forming.

Viscoelastic resin composition for vibration-damping material

A viscoelastic resin which comprises a reaction product of:

Viscoelastic resin for vibration damping material

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Chiba, Japan

Hiroshi Endoh