Fuji Photo Film Company, Limited

Nobutaka Yamaguchi

Masaaki Fujiyama

Eiichi Tadokoro

Katsumi Ryoke

Shinobu Iida

Norio Nasu

Masatoshi Takahashi

Kazuko Hanai

Hideaki Kosha

Takahito Miyoshi

Nobuo Tsuji

Toshimitu Okutu

Masami Suzuki

Kenichi Masuyama

Satoru Takayama

Masahiro Utsumi

Yasuyuki Yamada

Goro Akashi

Yasutoshi Okuzawa

Masahiro Utumi

Hiroshi Hashimoto

Tsutomu Okita

Masakazu Yoneyama

Takashi Yoneyama

Akira Kasuga

Noburo Hibino

Shigeo Komine

Yoshito Mukaida

Koji Sasazawa

Kazuo Kato

Sugihiko Tada

Haruo Masuda

Fumiaki Tsukuda

Masaaki Igarashi

Masaaki Fujiyana

Akira Kashiwagi

Masaki Fujiyama

An abrasive tape comprises a flexible substrate, and an abrasive layer overlaid on the flexible substrate by applying an abrasive coating composition containing abrasive grains and a binder onto the flexible substrate and drying the applied abrasive coating composition. The binder contains a vinyl chloride resin having a --SO.sub.3 M group, where M represents Li, Na or K, and an epoxy group.

Abrasive tape

An abrasive tape comprises a flexible non-magnetic substrate, and an abrasive coating film applied onto the flexible non-magnetic substrate and formed by kneading abrasive grains, a binder and an additive. The binder contains a resin which has, at a side chain, at least one polar group selected from the group consisting of ##STR1## where M represents a hydrogen atom, lithium, sodium, or potassium, M.sub.1 represents a hydrogen atom, lithium, sodium, potassium, or an alkyl group, and M.sub.2 represents a hydrogen atom, lithium, sodium, potassium, or an alkyl group.

Abasive tape

A method of making an abrasive tape comprises the steps of preparing an abrasive composition at least from abrasive grains and a binder, applying the abrasive composition onto a flexible substrate, and drying the applied abrasive composition. The step of preparing the abrasive composition comprises kneading processing and attritor dispersion processing which are carried out for at least a part of the abrasive grains and at least a part of the binder.

Method of making abrasive tape

An abrasive tape comprises a flexible non-magnetic substrate, and an abrasive coating film applied onto the flexible non-magnetic substrate and formed by kneading an abrasive material, a binder, and a lubricant essentially consisting of a fatty acid, a fatty acid ester, a silicone oil, and a surface active agent.

An abrasive tape comprises a flexible non-magnetic substrate, and an abrasive coating film essentially consisting of an abrasive material, a binder and an additive kneaded together and applied onto the flexible non-magnetic substrate. The abrasive material has a Mohs hardness of 6 or higher, and the binder essentially consists of a vinyl chloride-vinyl acetate copolymer, a prepolymer having an isocyanate group at a terminal, and an organic amine.

An abrasive tape comprises a flexible non-magnetic substrate, and an abrasive coating film applied onto the flexible non-magnetic substrate and formed by kneading an abrasive material and a binder essentially consisting of a vinyl chloride-vinyl acetate-maleic acid copolymer, a polyamide resin and an epoxy resin.

A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer being provided on one surface of the support and a backing layer being provided on the surface of the support opposite to said magnetic layer, the backing layer contains binder and non-magnetic particles comprised of (i) corbon black having an average particle size of 0.1 to 1.0 .mu.m and (ii) particles of abrasives having a Mohs' hardness of at least 6 and an average particle size of 1 .mu.m or less, with the non-magnetic particles in said backing layer being used in an amount of 40 to 300 parts by weight per 100 parts by weight of binder.

Magnetic recording medium

A magnetic recording medium is described, comprising a magnetic layer coated on one side of a non-magnetic support and a backing layer coated on the opposite side of the non-magnetic support, wherein the backing layer is provided after the magnetic layer has been subjected to calendering treatment and the backing layer comprises (i) non-magnetic particles including carbon black particles having an average particle diameter of from 0.1 to 1 .mu.m and (ii) a binder composition comprising from 50 to 95 wt % of a resin having a 100% modulus at 150 kg/cm.sup.2 or less based on the total weight of the binder composition, and the weight ratio of non-magnetic particles to binder composition contained in the backing layer is from 300/100 to 40/100.

A magnetic recording medium is described, comprising a non-magnetic support having provided thereon a magnetic layer being provided on one surface of the support and a backing layer being provided on the surface of the support opposite to said magnetic layer, the backing layer containing (A) a binder comprised of resin having a 100% modulus of 150 kg/cm.sup.2 or less present in an amount of 50 to 95 wt % based on the total weight amount of binder and (B) non-magnetic particles comprised of (i) carbon black having an average particle size of more than 0.1 .mu.m to 1.0 .mu.m, and (ii) carbon black having an average particle size of 0.01 .mu.m to 0.1 .mu.m in a weight ratio of carbon black (i)/carbon black (ii) of 95/5 to 5/95, with the non-magnetic particles in the backing layer being present in an amount of 40 to 300 parts by weight per 100 parts by weight of the total binder.

A magnetic recording medium is described, comprising a non-magnetic support having a magnetic layer and a backing layer which is provided on the surface of the support opposite to the magnetic layer, the backing layer containing (a) non-magnetic particles comprising carbon black having an average particle diameter of 0.1 to 1.0 .mu.m, (b) a binder comprising (i) a resin having 150 kg/cm.sup.2 or less of 100% modulus in an amount of at least 50 wt % based on the total amount of binder, and (ii) a diphenyl methane diisocyanate type hardening agent, with the amount of non-magnetic particles to total contained in the backing layer being 40 to 300 parts by weight of non-magnetic particles per 100 parts by weight of binder.

A magnetic recording medium comprised of a nonmagnetic support base having a magnetic recording layer on one surface thereof and a backing layer on the other surface thereof is disclosed. The backing layer is comprised of (1) carbon black having a particle size in the range of 10 to 150 m.mu., (2) graphite having a particle size of 3.mu. or less, and (3) a curing agent. By utilizing this particular backing layer the resulting recording medium has improved durability with respect to the backing layer and shows a decreased in the number of dropouts and scratches during use.

A magnetic recording medium is disclosed which comprises a non-magnetic support having provided thereon a magnetic recording layer and a backing layer on the opposite surface thereof, wherein said magnetic recording layer contains a fatty acid, said backing layer contains a cellulose resin, and said non-magnetic support has a Young's modulus of 7.times.10.sup.10 to 1.times.10.sup.13 dyn/cm.sup.2.

A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer on one side and a backing layer on the other side, wherein the backing layer contains (1) non-magnetic powders containing carbon black having an average particle diameter of from 0.1 to 1 .mu.m; (2) two or more binders wherein (a) at least one of the binders is a resin having a 100% modulus of from 15 to 150 kg/cm.sup.2 in an amount of from 50 to 95 wt % based on the total amount of the binders in the backing layer, and (b) the rest binder(s) is/are a resin other than the resin having a 100% modulus of from 15 to 150 kg/cm.sup.2, and the weight ratio of all the non-magnetic powders to all the binders in the backing layer is from 300:100 to 40:100; and (3) a polyisocyanate in an amount of from 15 to 40 wt % based on the total amount of the binders in the backing layer.

A magnetic recording material, which comprises a non-magnetic support having provided on one side thereof a magnetic layer and on the other side thereof a backing layer is disclosed. The binder of the backing layer is comprised of a combination of a cellulose resin, a vinylidene chloride resin, a polyurethane resin and a polyisocyanate. Use of the backing layer increases the durability of the tape and aids in preventing drop out.

A magnetic recording medium is disclosed. The medium is comprised of a non-magnetic support base having a surface with a center line average loughness (Ra) of not more then 0.035 .mu.m, having coated thereon a magnetic layer. The magnetic layer is comprised of a ferromagnetic powder, a fatty acid ester and two types of carbon black dispersed in a binder. The first type of carbon black has an average primary particles sizes of 10 to 30 m.mu.. The second type of carbon black has an average primary particle size of 60 to 120 m.mu.. The first type of carbon black and second type of carbon black are present in a mixing weight ratio in the range of 60/40 to 95/5. The magnetic recording medium has excellent electromagnetic properties and provides a tape having good running property and durability.

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Kanagawa, Japan

Nobutaka Yamaguchi