Patents by Inventor Matsuaki Nakamura

Matsuaki Nakamura has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4197347
    Abstract: A magnetic recording medium comprising a nonmagnetic support having thereon a magnetic recording layer of a ferromagnetic powder dispersed in a binder, wherein the ferromagnetic powder is a low vacuum evaporation process ferromagnetic metal powder subjected to a surface oxidation stabilizing processing and the low vacuum evaporation process ferromagnetic metal powder is one processed with an aqueous solution containing at least one anionic surface active agent.
    Type: Grant
    Filed: July 19, 1978
    Date of Patent: April 8, 1980
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Hiroshi Ogawa, Yasuo Tamai, Matsuaki Nakamura
  • Patent number: 4186228
    Abstract: A magnetic recording medium comprising a non-magnetic support having thereon a magnetic recording layer containing a finely divided ferromagnetic powder, a binder and at least one 1,2-epoxyalkane represented by the general formula (I) ##STR1## wherein R represents an alkyl group having 10 to 30 carbon atoms; in an amount of about 0.05 to about 3 parts by weight per 100 parts by weight of the ferromagnetic powder.
    Type: Grant
    Filed: September 7, 1978
    Date of Patent: January 29, 1980
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Hiroshi Ogawa, Matsuaki Nakamura, Yasuo Tamai
  • Patent number: 4154895
    Abstract: In a magnetic recording member comprising a non-magnetic support having provided thereon a magnetic layer comprising finely divided ferromagnetic powders dispersed in a binder, in which the binder comprises about 10 to about 70 wt% of (a) a polyester-polyurethane resin and about 30 to about 90 wt% of (b) a synthetic non-drying oil modified alkyd resin and (c) a polyisocyanate, wherein the molar ratio of the isocyanate groups present in the polyisocyanate (c) to the hydroxyl groups present in the synthetic non-drying oil-modified alkyd resin (b) ranges from about 0.8:1 to about 2.0:1. The binder system in accordance with the present invention provides excellent magnetic properties, particularly improved squareness ratio and 5 MHz output. The binder system of the present invention also enables the use of finely divided ferromagnetic alloy powders, with excellent magnetic properties being maintained when magnetic recording members are produced therefrom.
    Type: Grant
    Filed: December 20, 1977
    Date of Patent: May 15, 1979
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Hiroshi Ogawa, Masashi Aonuma, Matsuaki Nakamura, Yasuo Tamai
  • Patent number: 4135016
    Abstract: A magnetic recording material, which comprises a non-magnetic support having thereon a magnetic layer containing ferromagnetic powder dispersed in a binder, with the magnetic layer containing an organic silicone compound represented by the following general formula (I); ##STR1## wherein R, R' and R", which may be the same or different, each has 7 to 21 carbon atoms and represents an alkyl group, an alkenyl group, an alkadienyl group, an alkatrienyl group or an alkatetraenyl group, m represents an integer of 1 to 100; n represents an integer of 0 to 250; and m+n.ltoreq.300 and m.gtoreq.n/5.
    Type: Grant
    Filed: March 9, 1977
    Date of Patent: January 16, 1979
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Hiroshi Ogawa, Matsuaki Nakamura, Masashi Aonuma, Yasuo Tamai
  • Patent number: 4135218
    Abstract: A magnetic recording and reproducing apparatus provided with a magnetic head device comprising a supporting means having a recording magnetic head made of an alloy system magnetic material and a reproducing magnetic head made of a ferrite system magnetic material. The recording and reproducing heads are fixed relative to one another thereby eliminating the need for completely separate head mechanisms and for complex mechanisms to reliably interchange the positions of the two heads relative to the recording medium.
    Type: Grant
    Filed: May 19, 1976
    Date of Patent: January 16, 1979
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Matsuaki Nakamura, Tatsuji Kitamoto, Yasuo Tamai, Koshu Kurokawa
  • Patent number: 4110503
    Abstract: A magnetic recording member comprising a non-magnetic support having thereon a magnetic layer of a ferromagnetic powder dispersed in a binder, wherein the magnetic layer contains an organic silicone compound represented by the formula (I): ##STR1## wherein R and R', which may be the same or different, each is a saturated or unsaturated hydrocarbon group containing 7 to 21 carbon atoms, and n is an integer of 0 to 50.
    Type: Grant
    Filed: December 3, 1976
    Date of Patent: August 29, 1978
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Hiroshi Ogawa, Masashi Aonuma, Matsuaki Nakamura, Yasuo Tamai
  • Patent number: 4071654
    Abstract: A magnetic recording material comprising a non-magnetic flexible support having thereon a magnetic recording layer comprising a ferromagnetic powder dispersed in a binder, the surface of the non-magnetic flexible support having the magnetic recording layer thereon satisfying an S-factor expressed by the following relationship (I-1) ##EQU1## wherein S.sub.1 is the surface roughness in .mu.m of the surface of the non-magnetic flexible support having the magnetic recording layer thereon and d is the thickness in .mu.m of the magnetic recording layer, with the thickness (d) of the magnetic recording layer being about 5 .mu.m or less, and the back surface of the non-magnetic flexible support opposite that having the magnetic recording layer thereon satisfying an S-factor expressed by the following relationship (I-2) ##EQU2## wherein S.sub.2 is the surface roughness in .mu.m of the back surface of the non-magnetic support opposite that having the magnetic recording layer thereon and d is as described above.
    Type: Grant
    Filed: August 28, 1975
    Date of Patent: January 31, 1978
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Hiroshi Ogawa, Kazuhide Ishii, Matsuaki Nakamura, Yasuo Tamai, Goro Akashi
  • Patent number: 4009111
    Abstract: A magnetic recording medium for high density recording comprising a support having thereon a magnetic recording layer comprising a ferromagnetic metal powder of the Fe-Co-Cr-B system and having a coercive force of about 700 to 1500 orsteds in the oriented direction of the magnetic substance and a residual magnetic flux density of about 1500 gauses or more, the residual magnetic flux density of which after storage for 160 hours under the conditions of a temperature of 60.degree. C and 90%RH is 85% or more of the initial value thereof before storage under these conditions in a binder. The magnetic recording medium is especially suitable for high density recording, having sufficient sensitivity and excellent resistance.
    Type: Grant
    Filed: October 20, 1975
    Date of Patent: February 22, 1977
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuo Tamai, Masashi Aonuma, Matsuaki Nakamura, Hiroshi Agawa, Goro Akashi
  • Patent number: 3943012
    Abstract: A magnetic recording medium for high density recording comprising a support having thereon a magnetic recording layer comprising a ferromagnetic metal powder of the Fe-Co-Cr-B system and having a coercive force of about 700 to 500 oersteds in the oriented direction of the magnetic substance and a residual magnetic flux density of about 1500 gausses or more, the residual magnetic flux density of which after storage for 160 hours under the conditions of a temperature of 60.degree.C and 90%RH is 85% or more of the initial value thereof before storage under these conditions in a binder. The magnetic recording medium is especially suitable for high density recording, having sufficient sensitivity and excellent resistance.
    Type: Grant
    Filed: August 19, 1974
    Date of Patent: March 9, 1976
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuo Tamai, Masashi Aonuma, Matsuaki Nakamura, Hiroshi Agawa, Goro Akashi