Patents by Inventor Toyoaki Ishiwata

Toyoaki Ishiwata 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: 10047478
    Abstract: The present invention provides a prepreg comprising: a primary pre-pregnant made of a reinforced fiber substrate and an epoxy resin composition containing at least epoxy resin and thermoplastic resin impregnated into the reinforcing fiber that forms the reinforced fiber substrate; and a surface layer made of epoxy resin composition containing at least an epoxy resin and an epoxy resin-soluble thermoplastic resin that dissolves in the epoxy resin, the surface layer being formed on one or both surfaces of the primary prepreg; the prepreg being characterized in that only one of either the epoxy resin composition of the primary prepreg or the epoxy resin composition of the surface layer contains a hardening agent for an epoxy resin.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: August 14, 2018
    Assignee: TOHO TENAX CO., LTD
    Inventors: Takaya Suzuki, Toyoaki Ishiwata, Yoshinori Suzuki, Hiroshi Numata
  • Publication number: 20150274911
    Abstract: The invention provides a prepreg comprising: a primary prepreg composed of reinforcing fibers and a resin composition (I) impregnating the interior of a reinforcing fiber layer formed from these fibers; and a surface layer composed of a resin composition (II) formed on one or both sides of the primary prepreg; wherein the resin composition (I) is an epoxy resin composition [B] containing at least an epoxy resin and a thermoplastic resin, and the resin composition (II) is an epoxy resin composition [A] containing at least an epoxy resin and conductive particles.
    Type: Application
    Filed: September 25, 2013
    Publication date: October 1, 2015
    Inventors: Takaya Suzuki, Hajime Sakamoto, Toyoaki Ishiwata, Yoshitaka Umemoto
  • Publication number: 20140057515
    Abstract: The present invention provides a prepreg comprising: a primary pre-pregnant made of a reinforced fiber substrate and an epoxy resin composition containing at least epoxy resin and thermoplastic resin impregnated into the reinforcing fiber that forms the reinforced fiber substrate; and a surface layer made of epoxy resin composition containing at least an epoxy resin and an epoxy resin-soluble thermoplastic resin that dissolves in the epoxy resin, the surface layer being formed on one or both surfaces of the primary prepreg; the prepreg being characterized in that only one of either the epoxy resin composition of the primary prepreg or the epoxy resin composition of the surface layer contains a hardening agent for an epoxy resin.
    Type: Application
    Filed: March 21, 2012
    Publication date: February 27, 2014
    Inventors: Takaya Suzuki, Toyoaki Ishiwata, Yoshinori Suzuki, Hiroshi Numata
  • Publication number: 20110111663
    Abstract: Disclosed is an epoxy resin composition comprising at least component [A]: a glycidyl-amino-group-containing polyfunctional epoxy resin, component [B]: an epoxy resin other than the component [A], component [C]: a polyisocyanate compound, component [D]: an aromatic-amine-based curing agent, and component [E]: a thermoplastic resin, characterized in that the epoxy resin composition has an epoxy group concentration of 0.67 to 1.51 Eq/kg of the total amount of the components [A] to [D], and preferably that the component [E] is in a proportion of 10 to 50% by weight of the total epoxy resin composition. Use of a prepreg having the resin composition as a matrix resin makes it possible to obtain a composite material with excellent heat resistance and wet heat resistance together with high mechanical properties.
    Type: Application
    Filed: June 6, 2009
    Publication date: May 12, 2011
    Applicant: TOHO TENAX CO., LTD
    Inventors: Hironori Kawamoto, Toyoaki Ishiwata
  • Publication number: 20100285292
    Abstract: Disclosed is an aromatic polyimide film having specific elastic modulus and thermal expansion coefficient. Also disclosed is a method for producing such an aromatic polyimide film. Specifically disclosed is an aromatic polyimide film which is composed of an aromatic polyimide containing not less than 70 mol % of repeating units represented by the following formula (I): (I) while satisfying the following relations (1) and (2): CTEMD??11×MiMD+70??(1) CTETD??11×MiTD+70??(2) wherein CTEMD represents the in-plane thermal expansion coefficient (ppm·K?1) in the machine direction; CTETD represents the in-plane thermal expansion coefficient (ppm·K?1) in the transverse direction; MiMD represents the elastic modulus (GPa) in the machine direction; and MiTD represents the elastic modulus (GPa) in the transverse direction. Also specifically disclosed is a method for producing such an aromatic polyimide film.
    Type: Application
    Filed: March 27, 2006
    Publication date: November 11, 2010
    Inventors: Toyoaki Ishiwata, Jyuhou Matsuo, Nobuaki Kido
  • Patent number: 7407702
    Abstract: A polymetaphenylene isophthalamide-based polymer porous film having a satisfactory porous structure that exhibits excellent gas permeability and heat resistance. It is produced by a process which comprises casting a dope of the polymetaphenylene isophthalamide-based polymer and coagulating it in a coagulating bath. The porous film may also contain inorganic whiskers, and a composite porous film may be formed in combination with a separate thermoplastic polymer film.
    Type: Grant
    Filed: February 12, 2004
    Date of Patent: August 5, 2008
    Assignee: Teijin Limited
    Inventors: Takao Ohno, Jiro Sadanobu, Tsutomu Nakamura, Susumu Honda, Toyoaki Ishiwata
  • Publication number: 20070148480
    Abstract: A laminate which is advantageously used as an insulating layer for electronic package application and as an adhesive film for fixing a semiconductor wafer for semiconductor device application, laminates comprising the same and a process for manufacturing the above laminate. The laminate (I) comprises a base layer (A) and an adhesive layer (B) formed on one side or both sides of the layer A, the layer A is a film made of (A-1) a specific wholly aromatic polyimide (PIA-1) or (A-2) a specific wholly aromatic polyamide (PAA-2); and the layer B comprises (B-1) a specific wholly aromatic polyimide (PIB-1), (B-2) a specific wholly aromatic polyamide (PAB-2), or (B-3) a specific resin composition (RCB-3) comprising a wholly aromatic polyimide (PIB-3) and a specific wholly aromatic polyamide (PAB-3), laminates comprising the same and a process for manufacturing the above laminate.
    Type: Application
    Filed: December 22, 2004
    Publication date: June 28, 2007
    Inventors: Toyoaki Ishiwata, Toru Sawaki, Takashi Yoshitomi, Tsutomu Nakamura
  • Publication number: 20070100127
    Abstract: An oriented polyimide film with a high Young's modulus, satisfactory moist heat resistance and low moisture absorptivity, and a process for its production. The polyimide film is composed mainly of a pyromellitic acid component, with a p-phenylenediamine component at between 30 mole percent and 99 mole percent and a diamine component represented by the structural unit of the following formula (II) at between 1 mole percent and 70 mole percent: (wherein ArIIa and ArIIb are each independently a C6-20 aromatic group optionally having an non-reactive substituent, and X in structural unit (II) consists of at least one group selected from among —O—, —O—ArIIc—O—, —SO2— and —O—ArIId—O—ArIIe—O—), and the polyimide film is characterized by having two perpendicular directions in which the in-plane Young's modulus is 3 GPa or greater, and having a moisture absorptivity of no greater than 3.3 wt % at 72% RH, 25° C.
    Type: Application
    Filed: March 31, 2003
    Publication date: May 3, 2007
    Inventors: Toyoaki Ishiwata, Tsutomu Nakamura, Kazunori Kojima, Toru Sawaki
  • Publication number: 20060134407
    Abstract: There are provided an adhesive sheet, exhibiting a specific peel strength and shear peel strength and being composed of a base material (A) comprising a fully aromatic polyimide film having a glass transition temperature of 200° C. or above and a thermal adhesive layer (C) comprising a fully aromatic polyamide having a glass transition temperature of 200-500° C., as well as a laminate composed of the sheet and a process for its production. Also provided is a method of release after treatment of the laminate composed of the adhesive sheet, to obtain a laminate having the target to-be-treated layer.
    Type: Application
    Filed: January 28, 2004
    Publication date: June 22, 2006
    Inventors: Takashi Yoshitomi, Kazunori Kojima, Tsutomu Nakamura, Toyoaki Ishiwata, Toru Sawaki
  • Patent number: 6858701
    Abstract: A wholly aromatic polyester carbonate having a good color and excellent heat resistant stability. This polymer had an extremely low alkali metal content of 10 ppm or less. This polymer is advantageously produced by reacting an aromatic dicarboxylic acid, aromatic diol and diaryl carbonate in a specific molar ratio in the presence of a pyridine-based compound as a catalyst.
    Type: Grant
    Filed: May 31, 2001
    Date of Patent: February 22, 2005
    Assignee: Teijin Limited
    Inventors: Hiroshi Sakurai, Toyoaki Ishiwata, Takanori Miyoshi, Shunichi Matsumura
  • Patent number: 6812319
    Abstract: The present invention relates to a wholly aromatic polyester carbonate and a process for its production. An aromatic dicarboxylic acid, an aromatic diol, and a diaryl carbonate are used as starting materials in specific molar ratios, a prepolymerization step, a crystallization step, and a solid-phase polymerization step are essential steps, and a compression molding step is an optional step. This makes it possible to produce with good productivity a wholly aromatic polyester carbonate that has low coloration and a high degree of polymerization.
    Type: Grant
    Filed: April 11, 2003
    Date of Patent: November 2, 2004
    Assignee: Teijin Limited
    Inventors: Hiroshi Sakurai, Toyoaki Ishiwata, Shunichi Matsumura, Masayuki Chokai
  • Publication number: 20040161598
    Abstract: A polymetaphenylene isophtha lamide-based polymer porous film having a satisfactory porous structure that exhibits excellent gas permeability and heat resistance. It is produced by a process which comprises casting a dope of the polymetaphenylene isophthalamide-based polymer and coagulating it in a coagulating bath. The porous film may also contain inorganic whiskers, and a composite porous film may be formed in combination with a separate thermoplastic polymer film.
    Type: Application
    Filed: February 12, 2004
    Publication date: August 19, 2004
    Applicant: TEIJIN LIMITED
    Inventors: Takao Ohno, Jiro Sadanobu, Tsutomu Nakamura, Susumu Honda, Toyoaki Ishiwata
  • Patent number: 6696541
    Abstract: A method for crystallizing a low molecular weight aromatic polycarbonate effectively and a method for preparing a polycarbonate resin having a desired intrinsic viscosity by using the polycarbonate crystallized with the above method of crystallization. A low molecular weight aromatic polycarbonate (preferably, the one produced by melt polycondensation) is crystallized by bringing it into contact with an aromatic monohydroxy compound or a mixture of said compound and water. Or, a low molecular weight aromatic polycarbonate is melt mixed with at least one or more kinds of compounds selected from the group consisting of aromatic monohydroxy compounds, carbonic acid diester compounds and aromatic dihydroxy compounds to crystallize the low molecular weight aromatic polycarbonate. The crystallized product is heated at a temperature lower than its melting point under reduced pressure or in an inert gas flow to convert it into a high polymerized state.
    Type: Grant
    Filed: March 21, 2002
    Date of Patent: February 24, 2004
    Assignee: Teijin Limited
    Inventors: Tomonori Sakurai, Nobuaki Kido, Shunichi Matsumura, Toyoaki Ishiwata, Kazuteru Kohno, Hirotaka Suzuki, Hironori Haga, Toru Hikosaka
  • Patent number: 6646060
    Abstract: A resin composition containing a mixture produced by blending a crystalline polyamide expressed e.g. by formula (1) (in the formula, R1 is a bivalent organic aromatic group or aliphatic group having a carbon number of 2 to 30, optionally having substituent and optionally containing non-reactive groups such as ether group and aromatic group in the main chain, and Ar1 is an aromatic residue having a carbon number of 6 to 45 and optionally having substituent) with a thermoplastic polyester. The resin composition has excellent mechanical characteristics such as high elastic modulus, flow properties and heat-resistance and is suitable as a material for an electronic part for surface mounting.
    Type: Grant
    Filed: January 10, 2001
    Date of Patent: November 11, 2003
    Assignee: Teijin Limited
    Inventors: Kiyotsuna Toyohara, Toyoaki Ishiwata, Daisuke Ozaki, Jiro Sadanobu
  • Publication number: 20030181627
    Abstract: A wholly aromatic polyester carbonate having a good color and excellent heat resistant stability. This polymer had an extremely low alkali metal content of 10 ppm or less. This polymer is advantageously produced by reacting an aromatic dicarboxylic acid, aromatic diol and diaryl carbonate in a specific molar ratio in the presence of a pyridine-based compound as a catalyst.
    Type: Application
    Filed: December 2, 2002
    Publication date: September 25, 2003
    Inventors: Hiroshi Sakurai, Toyoaki Ishiwata, Takanori Miyoshi, Shunichi Matsumura
  • Publication number: 20030171528
    Abstract: The present invention relates to a wholly aromatic polyester carbonate and a process for its production. An aromatic dicarboxylic acid, an aromatic diol, and a diaryl carbonate are used as starting materials in specific molar ratios, a prepolymerization step, a crystallization step, and a solid-phase polymerization step are essential steps, and a compression molding step is an optional step. This makes it possible to produce with good productivity a wholly aromatic polyester carbonate that has low coloration and a high degree of polymerization.
    Type: Application
    Filed: April 11, 2003
    Publication date: September 11, 2003
    Applicant: TEIJIN LIMITED
    Inventors: Hiroshi Sakurai, Toyoaki Ishiwata, Shunichi Matsumura, Masayuki Chokai
  • Patent number: 6596839
    Abstract: A process for producing a wholly aromatic polyester which is excellent in heat resistance, mechanical properties and yet color and has a high degree of polymerization by melt polymerizing a dicarboxylic acid and a diol directly on an industrial scale at a low cost in a short period of time without esterifying the dicarboxylic acid or diol in advance. To produce the wholly aromatic polyester by reacting and molding an aromatic dicarboxylic acid such as terephthalic acid, an aromatic diol such as 2,2-bis(4-hydroxyphenyl)propane and a diaryl carbonate by heating, a combination of a specific pyridine compound and an alkali metal (bi)carbonate, a combination of a specific pyridine compound and an organic tin compound or a specific titanium compound is existent as a catalyst. Thereby, the wholly aromatic polyester having the above properties is obtained.
    Type: Grant
    Filed: July 8, 2002
    Date of Patent: July 22, 2003
    Assignee: Teijin Limited
    Inventors: Takanori Miyoshi, Hiroshi Sakurai, Toyoaki Ishiwata, Shunichi Matsumura
  • Publication number: 20030125504
    Abstract: A molten product of a wholly aromatic polyester carbonate or wholly aromatic polyester and an aromatic polycarbonate, which is rarely colored even when it is molten at a high temperature. This molten product is used for the production of car parts and electric and electronic parts.
    Type: Application
    Filed: December 13, 2002
    Publication date: July 3, 2003
    Inventors: Takanori Miyoshi, Hiroshi Sakurai, Shunichi Matsumura, Toyoaki Ishiwata
  • Publication number: 20030027972
    Abstract: A process for producing a wholly aromatic polyester which is excellent in heat resistance, mechanical properties and yet color and has a high degree of polymerization by melt polymerizing a dicarboxylic acid and a diol directly on an industrial scale at a low cost in a short period of time without esterifying the dicarboxylic acid or diol in advance.
    Type: Application
    Filed: July 8, 2002
    Publication date: February 6, 2003
    Inventors: Takanori Miyoshi, Hiroshi Sakurai, Toyoaki Ishiwata, Shunichi Matsumura
  • Patent number: 5853878
    Abstract: The present invention relates to an elastic fiber of polyester elastomer mainly comprising the polyester elastomer further comprising aromatic polyester component as a hard segment and poly(alkyleneoxide)glycol having a number-average molecular weight of 500 to 5000 as a soft segment, wherein a residual elongation after 400 percent stretching does not exceed 100 percent. Made of the polyester elastomer comprising 1,2-bis?4-(2-hydroxyethyl)phenoxy!ethane as the diol component constituting said aromatic polyester component, or 1,4-benzenediethanol and ethyleneglycol as the diol component constituting said aromatic polyester component, the elastic fiber features excellent elastic properties in the event of great deformation and provides suitable material for clothing.
    Type: Grant
    Filed: September 12, 1996
    Date of Patent: December 29, 1998
    Assignee: Teijin Limited
    Inventors: Toyoaki Ishiwata, Jiro Sadanobu