Kao Corporation

Teikoku Oil Co., Ltd.

Takashi Takeuchi

Tetsuya Imamura

Shinichiro Yasuda

Akira Ishikawa

Takayuki Ikenaga

Michihide Yamauchi

Nobuyuki Kishine

Shigetoshi Suzue

Hiroyuki Kanai

Takahide Minami

Tsuyoshi Ootani

Chiaki Abe

Takashi Tetsutani

Tetusya Imamura

Hiroshi Ito

Shoji Kobayashi

Tsuyoshi Ohtani

Kyusei Hasegawa

Syoji Kobayashi

A magnetic recording medium comprises a support the magnetic layer and a magnetic layer, coated on said support, comprising magnetic powder, a binder, (I) an ester compound having the formula: ##STR1## in which R1 and R2 are each a saturated alkyl group having 1 to 25 carbon atoms, branched or straight, the total carbon number of R1 and R2 being from 22 to 34, and R3 is a saturated or unsaturated alkyl group having 7 to 29 carbon atoms, branched or straight, and (II) an ester compound having the formula: ##STR2## in which R4 is an aliphatic hydrocarbon group having 1 to 29 carbon atoms, straight or branched, and R5 is an aliphatic hydrocarbon group having 1 to 23 carbon atoms, straight or branched, or a straight aliphatic hydrocarbon group having 24 to 36 carbon atoms, the total carbon number of R4 and R5 being 15 to 65. Alternatively, the ester (II) compound can be replaced by an aliphatic acid having from 8 to 30 carbon atoms. The magnetic layer comprising compounds (I) and (II) may also include an aliphatic acid having from 10-30 carbon atoms.

Magnetic recording medium

A magnetic recording medium exhibiting reduced abrasion and improved lubricant properties comprising a non-magnetic substrate having a magnetic layer containing a magnetic powder thereon, the magnetic layer including a glasslike carbon powder having an average particle diameter of from 0.1 to 2.0 .mu.m present in an amount of from 0.5 to 15 parts by weight per 100 parts by weight of the magnetic powder.

A magnetic toner comprises magnetic powder and a coating layer to cover said powder, the layer being a reaction product between (1) a silane coupling agent containing an amino group, an isocyanate group or an epoxy group and (2) one or more compounds having a functional group reactive with one of the reactive group on the silane coupling agent. A compound having a carboxyl group, an acid anhydride, an isocyanate compound or a ketene dimer is used for the amino group. A compound having a hydroxyl group, an amine compound or a compound having a carboxyl group is used for the isocyanate group. A compound having a hydroxyl group, a compound having a carboxyl group or a copolymer of a di- or monoalkylamino-alkyl (meth)acrylate and a hydrophobic vinyl monomer is used for the epoxy group. The magnetic toner is improved about dispersibility in a binder.

Coated magnetic toner powder

A magnetic recording medium excellent in magnetic properties and durability is provided which is characterized by containing magnetic powder coated with a reaction product between an aminosilane coupling agent and at least one compound selected from the group consisting of an acid anhydride of 6 to 22 carbon atoms and an alkylketene dimer. A magnetic paint containing said coated magnetic powder has good dispersibility of the magnetic powder and provides improved adhesion between the magnetic powder and a binder.

A stable micelle solution composition for recovering crude oil, which can form a homogeneous micro emulsion against brines in a wide range of salt concentrations. In a micelle solution composition comprising a hydrocarbon, brine, and a surface active agent, the above stated stable micelle solution composition can be obtained by specifying the surface active agent to be a mixture of (a) an ethylene oxide and propylene oxide block polymer, (b) an alkylbenzenesulfonate, (c) a polyoxyethylene alkyl ether sulfate or polyoxyethylene alkylphenol ether sulfate, and (d) a polyoxyethylene nonionic surface active agent other than the agent specified in (a).

Micelle solution compositions for recovering crude oil

Magnetic recording particles (i) are coated with a reaction product of (ii) an isocyanate compound such as polyisocyanate compounds and isocyanate compounds having a hydrolyzable alkoxysilane group, and (iii) a phosphoric ester of an alkanol, alkenol, alkylene oxide additives thereof or aliphatic carboxylic alkylene oxides.

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Utsunomiya, Japan

Takashi Takeuchi