Konishiroku Photo Industry Co., Ltd.

Konica Corporation

Hideki Murata

Hiroyuki Takagiwa

Tsuneo Wada

Sadatugu Terada

Kiyoshi Tamaki

Akitoshi Matsubara

Masao Asano

Kazumasa Matsumoto

Isamu Michihata

Toshihiko Kiriki

Katsuyuki Takeda

Nobuyuki Sekiguchi

Wataru Fujimatsu

Toshihiko Sato

Satoshi Matsunaga

Kenji Watanabe

Syozo Kikugawa

Sota Kawakami

Tetsuro Sunaga

A magnetic recording medium and a manufacturing process thereof are disclosed. The medium comprises a magnetic layer containing a binder, chromium oxide having an average particle size within the range of 0.3 to 0.5 .mu.m and a metal magnetic powder, wherein the binder comprises a polyurethane resin having a polar group selected from the group consisting of --SO.sub.3 M, --OSO.sub.3 M, --COOM, --PO (OM), and --OPO(OM).sub.2 wherein M represents a hydrogen atom or an alkali metal.

Disk type magnetic recording medium and process of manufacturing the same

A magnetic recording medium having a magnetic layer containing a urethane resin having a tensile strength of less than 200 kg/cm.sup.2 and an elongation at break of 900% or more, and another urethane resin having a tensile strength of 200 kg/cm.sup.2 or more and an elongation at break of less than 900%. This recording medium has good surface properties, good magnetic particles' orientation, great durability, and high wear resistance and produces high output.

Magnetic recording medium

A magnetic recording medium is described comprising a non-magnetic support layer, a magnetic layer and at least one layer of a high-molecular weight boron containing compound of the formula: ##STR1##

The invention relates to a method for producing a toner by polymerizing an aqueous suspension of a monomer in the presence of a dispersant selected from orthophosphate, pyrophosphate and polyphosphate, a colorant and an anionic surfactant. The polymerization product is then treated with dilute acid and rinsed with water whereby the dispersant is removed from the polymerization product.

Method for the production of toner for electrophotography and the toner

An optical element including an optical resin composition consisting essentially of a polycarbonate is disclosed. Said optical resin composition have a melt flow rate of more than or equal to 5.0 g/10 min. as measured based on ISO R-1133 Standard under the condition of 230.degree. C. and 5 kgf. and have a glass transition point of more than or equal to 100.degree. C. Said polycarbonate include a major repeating unit represented by the formula (I) or (II). ##STR1## wherein Ar.sub.1 and Ar.sub.2 each represent an arylene group or a cycloalkylene group; R represents an alkylene group, a cycloalkylene group, --O--, --O--Ar.sub.3 --O--, --S--, --SO--, --SO.sub.2 --, --SO.sub.2 --Ar.sub.3 --SO.sub.2 --, --R.sub.1 --Ar.sub.4 --R.sub.1 --, --O--R.sub.1 --O--, ##STR2## --CONH--R.sub.1 --NHCO--, or --Ar.sub.5 --R.sub.1 --; Ar.sub.3 and Ar.sub.4 each represent a phenylene group or a bisphenylene group; R.sub.1 represents an alkylene group; R.sub.2 represents an alkyl group; Ar.sub.5 represents a cycloalkylene group, --R.sub.1 --Ar.sub.4 --R.sub.1 --, --R.sub.1 --Ar.sub.5 --R.sub.1 --, --R.sub.1 --O--Ar.sub.4 --O--R.sub.1 --, or --R.sub.1 --O--Ar.sub.4 --X--Ar.sub.4 --O--R.sub.1 ; and X represents --SO.sub.2 --, --CO--, an alkylene group, or --R.sub.1 --Ar.sub.4 --R.sub.1 --.

Optical element and optical polycarbonate resin composition for the

Herein disclosed are a toner composition for the development of electrostatic latent images which comprises a polymer obtained by polymerizing a polymerizable monomer or monomers in the presence of a chlorinated polyolefin, and a method for preparing the same.

Toner composition for the development of electrostatic latent images and

A process for manufacturing towers and their use in developing an electrostatically charged image comprising polymerized grains formed by the suspension polymerization of an alpha-beta unsaturated polymeric monomer or monomers in the presence of a dispersion stabilizer selected from the group consisting of aluminum hydroxide, ferric hydroxide titanium hydroxide and thorium hydroxide.

Toner for developing an electrostatically charged image and

An electrostatic image developing toner comprising polymer particles produced by suspension polymerization of a polymerizable monomer in the presence of an emulsification-preventing agent. Such toners produce images of high image density.

Growing community of inventors

Hino, Japan

Hideki Murata