Toyo Boseki Kabushiki Kaisha

Haruhiko Narusawa

Takeshi Yatsuka

Yasunobu Sugyo

Hiroshi Fujimoto

Shigeji Konagaya

Haruo Asai

Susumu Tate

Yasuo Kato

Hideshi Kuzumoto

Akira Chiba

Youichi Watanabe

Masaya Tokai

Osamu Watanabe

A magnetic recording medium comprise a non-magnetic support and a magnetic layer formed thereon which is made of a composition comprising ferromagnetic particles and a resinous binder. The resinous binder comprises a polyurethane resin containing at least a high molecular polyol (A) and a diisocyanate (B) as its constituents. The high molecular polyol (A) comprises a polyol (a.sub.1) having a glass-transition temperature of 20.degree. C. or more and having a number average molecular weight in the range of 500 to 10,000, and the polyurethane resin has at least one hydroxyl group at its molecular terminals and the urethane bond concentration of the polyurethane resin is in the range of 500 to 1,500 equivalents/10.sup.6 g.

Magnetic recording medium comprising magnetic particles and a specified

A polyurethane resin composition containing a polyurethane resin composed of a high molecular weight polyol having a molecular weight of not less than 500, an organic polyisocyanate and optionally a compound having at least 2 active hydrogen-containing groups is disclosed. Not less than 30% by weight of the high molecular weight polyol is a polyester polyol, and the polyester polyol contains at least one tricyclic molecular skeleton in the molecular chain thereof in an amount of not less than 20 mole % based on total acid or glycol components.

Polyurethane resin composition

A novel ultra-high-molecular-weight polyester prepared from aromatic dicarboxylic acid or alkyl ester thereof and alkylene glycol, and having intrinsic viscosity of not less than 1.5 and insoluble polymer content of not more than 10% by weight.

Ultra-high-molecular-weight polyesters

A permselective membrance suitable for obtaining fresh water by the desalination of sea water and salt water is provided herein, said permselective membrane being prepared by the reaction of an aromatic polycarboxylic acid component with a mixed diamine component comprising a diaminodiphenylsulfone compound of the formula (I), ##STR1## wherein R.sup.1 is hydrogen atom or a C.sub.1 -C.sub.12 hydrocarbon group, R.sup.2 s may be same or different, each representing a monovalent organic group, and n is an integer of 0 or 1 to 3, and an alicyclic diamine compound containing two secondary amino groups in the same or different ring(s).

Permselective membrane

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Otsu, Japan

Haruhiko Narusawa