Hitachi Maxell, Limited

Hitachi, Ltd.

Hitachi Computer Peripherals Co., Ltd.

Hitachi Instrument Engineering Co., Ltd.

Sayaka Shinomoto

Takahiro Furutani

Kazushi Miyata

Tetsuo Mizumura

Hideo Daimon

Kenji Kohno

Nobumasa Nishiyama

Hiroaki Koyanagi

Noboru Isoe

Kouichi Hoashi

Yuko Uetani

Ryuichiroh Tamochi

Kouji Takai

A lubricant containing a fluorinated dicarboxylic acid of the formula: A.sup.1 --COO--R.sup.1 --Rf--R.sup.2 --OCO--A.sup.2 in which Rf is a divalent perfluoropolyether group; R.sup.1 and R.sup.2 are the same or different and represent a hydrocarbon group; and A.sup.1 and A.sup.2 are the same or different and represent an organic group having a carboxyl group, which allows two solid materials, for example, a magnetic recording medium and a magnetic head, to slide with low wearing at a low friction under various conditions.

Lubricant and magnetic recording medium comprising the same

An organic compound of the formula: R.sub.1 -Z.sub.1 -R.sub.3 -Z.sub.2 -R.sub.2 in which R.sub.1 and R.sub.2 represent a linear, branched or cyclic saturated or unsaturated hydrocarbon group, a polyether group, a polyester group, a polyamide group or a polycarbonate group; Z.sub.1 and Z.sub.2 represent an amide bond, an ether bond, a urethane bond, a urea bond or an amine salt bond formed by a reaction between an acid and an amine; and R.sub.3 is a group of the formula: --(CH.sub.2).sub.x --(CF.sub.2).sub.y --(CH.sub.2).sub.z -- in which x and z are an integer of 1 to 4, and y is an integer of 4 to 34 which is useful as a lubricant to be used, for example in a magnetic recording medium.

Organic triblock compound solid lubricant comprising the same and

A lubricant containing a branched aliphatic diester of the general formula: R.sub.1 R.sub.2 R.sub.3 C--(CH.sub.2).sub.n --X--R--X'--(CH.sub.2).sub.n --CR.sub.4 R.sub.5 R.sub.6 in which R.sub.1 to R.sub.6 independently represent a hydrocarbon group having 1-18 carbon atoms; R is a fluorinated hydrocarbon group having 6 to 18 carbon atoms; either one of X and X' represent either one of --OCO-- and --COO--, while the other of X and X' represent the other of --OCO-- and --COO--; and n is an integer from 0 to 6, and optionally an aliphatic amine of the general formula: R.sub.7 NR.sub.8 R.sub.9 in which R.sub.7, R.sub.8 and R.sub.9 independently represent a hydrogen atom or a hydrocarbon group having 1 to 26 carbon atoms.

Lubricant and magnetic recording medium using the same

A lubricating agent contains at least one alkylene oxide derivative having an alkylene oxide group and an ester moiety or an ammonium salt moiety, which is represented by the following general formula (1), (2), (3) or (4) :

Lubricating agent and magnetic recording medium comprising the same

A lubricating agent contains at least one alkylene oxide derivative having an alkylene oxide group and an ester moiety or an ammonium salt moiety, which is represented by the following general formula (1), (2), (3) or (4): R.sup.1 --O--(R.sup.2 O).sub.m --R.sup.3 --COO--R.sup.4 (1) R.sup.1 O--(R.sup.2 O).sub.m --R.sup.3 --COONH.sub.3 --R.sup.4 (2) R.sup.4 --OCO--R.sup.3 --O--(R.sup.2 O).sub.m --R.sup.3 --COO--R.sup.4 (3) R.sup.4 --NH.sub.3 OCO--R.sup.3 --O--(R.sup.2 O).sub.m --R.sup.3 --COONH.sub.3 --R.sup.4 (4) wherein R.sup.1 is a hydrocarbon group having 1 to 26 carbon atoms or a hydrogen atom, R.sup.2 is a hydrocarbon group having 1 to 6 carbon atoms, R.sup.3 is a hydrocarbon group having 1 to 26 carbon atoms, R.sup.4 is a hydrocarbon or fluorocarbon group having 1 to 26 carbon atoms, and m is from 1 to 12. There is also disclosed a magnetic recording medium having a non-magnetic substrate and a magnetic layer provided on at least one surface of the substrate, wherein the magnetic layer has the lubricating agent in or on the magnetic layer.

An organic compound of the formula: R.sub.1 --Z.sub.1 --R.sub.3 --Z.sub.2 --R.sub.2 in which R.sub.1 and R.sub.2 represent a linear, branched or cyclic saturated or unsaturated hydrocarbon group, a polyether group, a polyester group, a polyamide group or a polycarbonate group; Z.sub.1 and Z.sub.2 represent an amide bond, an ether bond, a urethane bond, a urea bond or an amine salt bond formed by a reaction between an acid and an amine; and R.sub.3 is a group of the formula: --(CH.sub.2).sub.x --(CF.sub.2).sub.y --(CH.sub.2).sub.z in which x and z are an integer of 1 to 4, and y is an integer of 4 to 34 which is useful as a lubricant to be used, for example in a magnetic recording medium.

A personal information display system is provided with a portable information display device for reading information to be used from a storage medium, a communication network for transmission of information, input/output apparatus for input/output of information, an input/output control apparatus connected between the communication network and the input/output apparatus, an information control apparatus having a hierarchical memory connected to the communication network, and an information output apparatus connected to the information control apparatus to transfer information to the storage medium of the portable information display device.

Growing community of inventors

Kyoto, Japan

Sayaka Shinomoto