Tdk Corporation

Hodogaya Chemical Co., Ltd.

Shigeru Shimada

Yuichi Kubota

Masaharu Nishimatsu

Hiroyuki Arioka

Toshiaki Ide

Yoshiaki Saito

Kazunori Tamazaki

Susumu Jinbo

Akira Kuroda

Shinzi Ishikawa

Junichi Tomiuga

Hideyuki Isii

Disclosed is a polyoxyalkylene derivative which is useful for a carboxyl group-containing polyurethane resin, can easily introduce a carboxyl group into a polyurethane resin skeleton, and has a low melting point or is in a liquid state at normal temperature. The polyoxyalkylene derivative is represented by formula (I): ##STR1## wherein R.sub.1 represents a hydrogen atom or an alkyl group having from 1 to 3 carbon atoms; R.sub.2 represents an alkylene group having from 1 to 6 carbon atoms or an arylene group having from 6 to 8 carbon atoms; A represents an alkylene group having from 4 to 7 carbon atoms; B represents an alkylene group having from 2 to 6 carbon atoms; l represents from 0 to 2; m represents from 0.1 to 35; n represents from 0.1 to 50; and 0.5&lt;(m+n)&lt;50.

Carboxyl group-containing polyoxyalkylene derivative

A back coating resin composition for a magnetic recording medium comprising:

Resin composition and magnetic recording medium employing the composition

A magnetic recording medium, obtained by preparing a radiation-sensitive curing resin by modification of a copolymer of (A) vinyl chloride, (B) a vinyl carboxylate, (C) an unsaturated carboxylic acid and (D) an unsaturated carboxylic anhydride, containing 50 to 80% by weight of (A) based on the total of (A) and (B), 10 to 30% by weight of (D) based on the total of (C) and (D) and a total of 1 to 5 parts by weight of (C) and (D) based on 100 parts by weight of (A) and (B) and having an average polymerization degree of 100 of 400, and a magnetic powder thereby producing a magnetic paint, applying said magnetic paint to a non-magnetic substrate, and solidifying the resultant coating of paint on said substrate by exposure to radiation.

Magnetic recording medium

A magnetic recording medium, produced by preparing a resin solution for magnetic paint containing a mixture of a radiation curable resin modified copolymer of (A) vinyl chloride, (B) a vinyl carboxylate, (C) vinyl alcohol, (D) an unsaturated carboxylic acid and (E) an unsaturated carboxylic anhydride, containing 50 to 90% by weight of (A) based on the total of the amounts of (A), (B) and (C), 0 to 30% by weight of (E) based on the total of the amounts of (D) and (E), and 1 to 5 parts by weight of the total of (D) and (E) based on 100 parts by weight of the total of (A), (B) and (C) and having an average polymerization degree of 100 to 400 and an other radiation curable resin, and a magnetic powder, applying the resultant magnetic paint to a nonmagnetic substrate, and curing the applied layer of paint with radiation.

A magnetic recording medium, produced by preparing a resin solution for magnetic paint having as a main component thereof a copolymer of (A) vinyl chloride, (B) a vinyl carboxylate, (C) an unsaturated carboxylic acid, (D) an unsaturated carboxylic anhydride and (E) vinyl alcohol, containing 50 to 90% by weight of (A) based on the total of the amounts of (A), (B) and (E), 1 to 15% by weight of (E) based on the total of the amounts of (A), (B) and (E), 0 to 30% by weight of (D) based on the total of amounts of (C) and (D), and 1 to 5 parts by weight of the total of (C) and (D) based on 100 parts by weight of the total of (A), (B) and (E) and having an average polymerization degree of 100 to 400, mixing 10 to 80% by weight of said resin solution with 90 to 20% by weight of a radiation curable resin, blending the resultant mixture as a main component with a magnetic powder, applying the resultant magnetic paint to a non-magnetic substrate, and curing the applied layer of paint with radiation.

A magnetic recording medium comprising a transparent plastic film substrate, a primer coating layer formed on the substrate and a magnetic layer for magnetic recording formed on the primer coating layer, wherein said primer coating layer is formed by dispersing carbon black in a radiation curable coating material composed essentially of at least one oligomer or polymer containing at least one radiation curable unsaturated double bond per molecule and curing the resulting dispersion by radiation.

A magnetic recording medium comprising fine ferromagnetic particles as the main component and a binder composed of a mixture of a radiation sensitive soft resin, a radiation sensitive modified resin and a partially saponified vinyl chloride-vinyl acetate copolymer containing at least 0.5% by weight of maleic acid, said binder being cross-linked and polymerized by radiation.

A magnetic recording medium, produced by preparing a resin solution for magnetic paint having as a main component thereof a copolymer of (A) vinyl chloride, (B) a vinyl carboxylate, (C) an unsaturated carboxylic acid and (D) an unsaturated carboxylic anhydride, containing 50 to 80% by weight of (A) based on the total of the amounts of (A) and (B), 60 to 90% by weight of (D) based on the total of the amounts of (C) and (D), and 1 to 5 parts by weight of the total of (C) and (D) based on 100 parts by weight of the total of (A) and (B) and having an average polymerization degree of 100 to 400, mixing 10 to 80% by weight of said resin solution weigh 90 to 20% by weight of a radiation-sensitive curing resin, blending the resultant mixture as a main component with a magnetic powder, applying the resultant magnetic paint to a non-magnetic substrate, and solidifying the applied layer of paint with radiation.

A water-base polyurethane emulsion useful as an adhesive or coating material for a polyolefin resin, which comprises a polyol component and a polyisocyanate component, characterized in that a hydrogenated polyalkadiene polyol is used as the polyol component.

Growing community of inventors

Saku, Japan

Shigeru Shimada