Fuji Photo Film Company, Limited

The Nisshin Oil Mills, Ltd.

Katsumi Ryoke

Masatoshi Takahashi

Eiichi Tadokoro

Masaaki Fujiyama

Nobutaka Yamaguchi

Kazuko Hanai

Hideaki Kosha

Takashi Yoneyama

Toshiyuki Kitahara

Masaki Suzuki

Akihiro Hashimoto

Yutaka Kakuishi

Shinobu Iida

Tsutomu Okita

Toshimitu Okutu

Kenichi Masuyama

Masami Sato

Tadashi Ishiguro

Keisuke Yamada

Nobuo Tsuji

Yasuo Nishikawa

Toshihiko Miura

Nobuyuki Yamamoto

Yuzo Higaki

Norio Nasu

Kazuo Hasumi

Toshihisa Okamura

Keiji Mihayashi

Yasuyuki Yamada

Akihiro Matsufuji

Masakazu Yoneyama

Masami Suzuki

Shinzo Kishimoto

Katsuhiko Meguro

Hiroaki Doushita

Yasuhiro Abe

Naohiko Sugimoto

Hideomi Watanabe

Sugihiko Tada

Youichi Hayata

Nobuyoshi Asada

Tetsuji Nishida

Nobuhisa Sekiguchi

Masahiro Utsumi

Tsugio Izaki

Junji Yazawa

Tatsuya Oguri

A polishing member for use in polishing of an end face of an optical fiber connector ferrule comprises a substrate and a polishing layer, which is overlaid on the substrate and which comprises a binder and fine polishing particles dispersed in the binder. Agglomerated fine silica particles having a mean particle size falling within the range of 0.1 &mgr;m to 4 &mgr;m are utilized as the fine polishing particles contained in the polishing layer, and a thickness of the substrate falls within the range of 25 &mgr;m to 150 &mgr;m. The polishing with the polishing member is performed while a polishing liquid, which is constituted of water or a silica slurry, is being supplied onto a surface of the polishing layer. The polishing liquid is free from a base or an acid. The polishing layer has a dry thickness falling within the range of 5 &mgr;m to 15 &mgr;m.

Polishing member and process for producing the same

An abrasive member for a very high return loss optical connector ferrule is used in abrading an end of an optical connector ferrule having a ferrule hole, in which an optical fiber has been inserted and secured, into a convex spherical surface. The abrasive member comprises a flexible substrate and an abrasive layer, which is formed on the surface of the flexible substrate and comprises a binder and abrasive grains. The surface roughness Ra, expressed in terms of arithmetic mean deviation, of the abrasive layer falls within the range of 0.01 .mu.m to 0.05 .mu.m. The abrasive member carries out polishing such that the surface smoothness of the ferrule surface and the optical fiber surface may be kept high, such that a difference in level between the ferrule surface and the optical fiber surface may not occur, and such that the very high return loss characteristics may thereby be obtained.

Abrasive member for very high return loss optical connector ferrules

An abrasive member comprises a substrate and an abrasive layer, which is constituted of a binder and abrasive grains dispersed therein, wherein the abrasive grains are constituted of sintered .alpha.-alumina grains. The abrasive member is capable of abrading a material to be abraded such that no abnormal abrasion scratch may occur on the abraded material.

Abrasive member

An abrasive tape for cleaning a magnetic information reading apparatus for photographic use. The tape comprises an abrasive layer including an abrasive and a binder and a support therefor. The support havs a characteristic thickness between 40 .mu.m and 180 .mu.m. An abrasive tape package for the apparatus comprises a cartrigde body, and a spool which is placed inside the cartrigde and rotatably supported by the cartrigde through a shaft. In the package, the spool is wound by the abrasive tape wherein the support has a thickness between 40 .mu.m and 180 .mu.m; the cartrigde has a feed passway for sending out the abrasive tape; and a pair of apparatus abrasive tape retainers are attached to the inside of the both ends of the shaft.

Abrasive tape for magnetic information reading apparatus for

An abrasive tape having an abrasive layer primarily containing abrasive grains and a binder and formed on a flexible substrate and a member to be cleaned are fed in substantially opposite directions with the abrasive layer and a surface of the member kept in contact with each other with the ratio of the feed rate of the member to the feed rate of the abrasive tape kept not higher than 1/1.

Cleaning method using abrasive tape

An abrasive member comprises a substrate and an abrasive layer, which is overlaid upon the substrate and is constituted of a binder and abrasive grains dispersed therein. The abrasive grains contain aluminum oxide grains, which have the characteristics such that the sodium content, as calculated in terms of NaO, in the abrasive grains may be at most 0.1% by weight, and such that the grain diameter of .alpha.-crystal grains may be at most 5 .mu.m. The abrasive member is capable of abrading a material to be abraded such that scratches, corrosion, or the like, may not occur with the abraded material, and the abraded material having good quality may be obtained.

An abrasive member comprises a non-magnetic substrate and a plurality of abrasive layers, which are overlaid upon the non-magnetic substrate, each of the abrasive layers mainly containing a binder and hard abrasive grains, which have a Mohs hardness of at least 6 and are dispersed in the binder. The plurality of the abrasive layers include a top abrasive layer and a lower abrasive layer, which is formed between the non-magnetic substrate and the top abrasive layer. The thickness of the top abrasive layer is at most A/2, where A represents the thickness of the lower abrasive layer. The mean grain diameter of the abrasive grains contained in the top abrasive layer is at most B/2, where B represents the mean grain diameter of the abrasive grains contained in the lower abrasive layer.

An abrasive tape comprises a substrate and an abrasive layer, which is overlaid on the substrate and is constituted of fine abrasive grains and a binder, wherein the abrasive layer contains an alkyl sulfosuccinic acid salt ester. The abrasive tape gives little scratching and little chipping to materials to be abraded and has a sufficiently high abrasive powder.

Abrasive tape

An abrasive tape is disclosed, comprising a flexible support having thereon an abrasive layer containing mainly an abrasive particle and a binder resin, wherein said abrasive layer has a thickness of from 0.3 to 10.0 .mu.m, an interlayer is provided between said abrasive layer and said flexible support, the thickness of said interlayer is 1 .mu.m or more, 30% or more of the thickness of said flexible support and larger than the thickness of said abrasive layer, and said interlayer has a Young's modulus of from 10 to 150 Kg/mm.sup.2. The abrasive tape may be used for cleaning and polishing a magnetic head.

Abrasive tape having an interlayer for magnetic head cleaning and

An abrasive tape comprises a flexible substrate and an abrasive layer, which is overlaid on the flexible substrate and which primarily contains fine abrasive grains and a binder resin. The thickness of the flexible substrate falls within the range of 3 .mu.m to 10 .mu.m. The fine abrasive grains of the abrasive layer may contain at least one kind of grains, which have a mean grain diameter falling within the range of 0.05 .mu.m to 20 .mu.m and which are selected from the group consisting of chromium oxide grains, .alpha.-alumina grains, silicon carbide grains, non-magnetic iron oxide grains, and diamond grains.

A surface of a member having intrinsic projections thereon is polished to remove the intrinsic projections. An abrasive tape is formed of a substrate and an abrasive layer formed thereon. The abrasive layer primarily contains abrasive grains and a binder. The abrasive tape and the member are slid in substantially opposite directions with the abrasive layer and the surface of the member kept in contact with each other.

Polishing method

A magnetic recording medium comprises a magnetic layer containing a ferromagnetic powder, a binder and an abrasive material having a Mohs hardness of 8 or more on a non-magnetic support, wherein the average protrusion height, which represents the length between the central line of the surface roughness of the sectional curve of the magnetic layer and the upper end of the abrasive material existing (i) above the central line of the surface roughness of the magnetic layer and (ii) in the surface layer of the magnetic layer, is 15 nm or less. A process for preparing the magnetic recording medium comprises coating on a non-magnetic support a magnetic layer containing a ferromagnetic powder, a binder and an abrasive material having a Mohs hardness of 8 or more, and then polishing the surface of the magnetic layer with an abrasive tape, wherein as the abrasive tape there is used one containing at least one abrasive material having a higher Mohs hardness than the abrasive material to be incorporated in the magnetic layer.

Magnetic recording medium having a magnetic layer with a specified

An abrasive tape for polishing a magnetic head includes a substrate and an abrasive layer which is formed on the substrate. The abrasive layer is composed of abrasive grains and a binder having an acidic functional group. The abrasive layer contains basic carbon black having a pH within the range of 7 to 10 and a mean grain size of 0.01 to 0.1 .mu.m.

A magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer comprising a ferromagnetic powder and a binder resin is disclosed. The magnetic layer contains a first carbon black having a DBP absorption of from 40 to 120 ml/100 g and a second carbon black having a DBP absorption of from 140 to 200 ml/100 g. Both carbon black have an average particle size of from 5 to 35 m.mu.. The medium maintains a high output level and has excellent running stability. Therefore, the dropout due to abrasion caused by an increase in friction coefficient and output reduction due to head clogging, can be avoided.

Magnetic recording medium having a magnetic layer containing two carbon

A magnetic recording medium is described comprising a nonmagnetic support having formed thereon a magnetic layer containing a ferromagnetic powder, an abrasive, and a binder, wherein the ferromagnetic powder is a metal magnetic powder having a crystallite size of not larger than 200 .ANG., the abrasive comprises (i) an inorganic powder having a Mohs' hardness of more than 9 and a mean particle size of 0.1 to 0.9 .mu.m which is contained in an amount of from 0.1 to 10 parts by weight per 100 parts by weight of the ferromagnetic powder, and a center-line average surface roughness (Ra) of the magnetic layer is less than 5 nm. The magnetic recording medium exhibits improved properties in C/N, running durability and drop-out. A process of producing the recording medium is also disclosed involving a calender treatment with at least one pair of metal rolls.

Magnetic recording medium and process for production thereof

Growing community of inventors

Kanagawa, Japan

Katsumi Ryoke