Patents Assigned to Toho Tenax Co., Ltd.
  • Patent number: 10647849
    Abstract: The present invention provides an epoxy resin composition comprising at least the following component [A], component [B] and component [C], the epoxy resin composition being characterized in that: the mixture of component [A] and component [B] is a mixture that, when temperature is increased at 2° C./min, begins to thicken at temperature (T1) and completes thickening at temperature (T2), temperature (T1) being 80-110° C. and temperature (T1) and temperature (T2) satisfying the relationship of expression (1) 5° C.?(T2?T1)?20° C. expression (1); and the mixture of component [A] and component [C] is a mixture that, when temperature is increased at 2° C./min, begins to cure at temperature (T3), temperature (T1) and temperature (T3) satisfying the relationship of expression (2) 5° C.?(T3?T1)?80° C. expression (2). Component [A]: epoxy resin Component [B]: thickening particle Component [C]: curing agent.
    Type: Grant
    Filed: March 30, 2016
    Date of Patent: May 12, 2020
    Assignee: TOHO TENAX CO., LTD.
    Inventors: Toru Kaneko, Yuko Okano
  • Patent number: 10544274
    Abstract: A prepreg includes conductive fibers impregnated with a matrix resin, the prepreg having a conductive region where a conductive material is dispersed in the resin. In the present invention, a resin layer composed of at least the matrix resin preferably is present on one or both surfaces of a conductive fiber layer composed of at least the conductive fibers, and the conductive region is present at least in the resin layer. In addition, the above-described conductive region preferably is present continuously in the thickness direction. The conductive region preferably is a conductive region where the conductive material is dispersed in the matrix resin, and the resin in the conductive region preferably forms a continuous phase with the matrix resin in other regions. A volume resistivity of the conductive region preferably is 1/1,000 or less of that of other regions of the matrix resin.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: January 28, 2020
    Assignee: Toho Tenax Co., Ltd.
    Inventors: Kazuma Kurokawa, Hironori Kawamoto, Yoshitaka Umemoto, Akio Nakaishi
  • Patent number: 10316433
    Abstract: Carbon fibers having a high tensile strength satisfy the relationship represented by formula (1) and one of the relationships represented by formulas (2) to (5): La?1??(1), La??0.5+0.01×TM when 170?TM?230??(2), La??37.3+0.17×TM when 230<TM?240??(3), La??2.5+0.025×TM when 240<TM?300??(4), and La?2+0.01×TM when 300<TM??(5) where La is a crystal size in nm in a direction parallel to an axis of the fibers measured with by X-ray diffraction, and TM is a tensile modulus in GPa.
    Type: Grant
    Filed: March 29, 2016
    Date of Patent: June 11, 2019
    Assignee: TOHO TENAX Co., LTD.
    Inventors: Yoshinori Suzuki, Toshimichi Nakajima
  • Publication number: 20190040551
    Abstract: A carbon fiber manufacturing method includes joining first and second target fiber bundles with a joining fiber bundle, and carbonizing the joined bundles by feeding them through one or more carbonization furnaces. The joining includes forming an overlap between a first end of the joining fiber bundle and a second end of the first target fiber bundle and jetting a fluid to the overlap to form a first entangled portion, and forming an overlap between a second end of the joining fiber bundle and a first end of the second target fiber bundle and jetting a fluid to the overlap to form a second entangled portion.
    Type: Application
    Filed: January 31, 2017
    Publication date: February 7, 2019
    Applicant: TOHO TENAX CO., LTD.
    Inventors: Fumio AKIYAMA, Tadayuki AOYAMA, Ichiro KITANO
  • 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: 20180208729
    Abstract: A prepreg includes conductive fibers impregnated with a matrix resin, the prepreg having a conductive region where a conductive material is dispersed in the resin. In the present invention, a resin layer composed of at least the matrix resin preferably is present on one or both surfaces of a conductive fiber layer composed of at least the conductive fibers, and the conductive region is present at least in the resin layer. In addition, the above-described conductive region preferably is present continuously in the thickness direction. The conductive region preferably is a conductive region where the conductive material is dispersed in the matrix resin, and the resin in the conductive region preferably forms a continuous phase with the matrix resin in other regions. A volume resistivity of the conductive region preferably is 1/1,000 or less of that of other regions of the matrix resin.
    Type: Application
    Filed: July 24, 2015
    Publication date: July 26, 2018
    Applicant: Toho Tenax Co., Ltd.
    Inventors: Kazuma KUROKAWA, Hironori KAWAMOTO, Yoshitaka UMEMOTO, Akio NAKAISHI
  • Publication number: 20180105690
    Abstract: The present invention provides an epoxy resin composition comprising at least the following component [A], component [B] and component [C], the epoxy resin composition being characterized in that: the mixture of component [A] and component [B] is a mixture that, when temperature is increased at 2° C./min, begins to thicken at temperature (T1) and completes thickening at temperature (T2), temperature (T1) being 80-110° C. and temperature (T1) and temperature (T2) satisfying the relationship of expression (1) 5° C.?(T2?T1)?20° C. expression (1); and the mixture of component [A] and component [C] is a mixture that, when temperature is increased at 2° C./min, begins to cure at temperature (T3), temperature (T1) and temperature (T3) satisfying the relationship of expression (2) 5° C.?(T3?T1)?80° C. expression (2).
    Type: Application
    Filed: March 30, 2016
    Publication date: April 19, 2018
    Applicant: TOHO TENAX CO., LTD.
    Inventors: Toru KANEKO, Yuko OKANO
  • Publication number: 20180051399
    Abstract: Carbon fibers having a high tensile strength satisfy the relationship represented by formula (1) and one of the relationships represented by formulas (2) to (5): La?1??(1), La??0.5+0.01×TM when 170?TM?230??(2), La??37.3+0.17×TM when 230<TM?240??(3), La??2.5+0.025×TM when 240<TM?300??(4), and La?2+0.01×TM when 300<TM??(5) where La is a crystal size in nm in a direction parallel to an axis of the fibers measured with by X-ray diffraction, and TM is a tensile modulus in GPa.
    Type: Application
    Filed: March 29, 2016
    Publication date: February 22, 2018
    Applicant: TOHO TENAX CO.,LTD.
    Inventors: Yoshinori SUZUKI, Toshimichi NAKAJIMA
  • Patent number: 9745671
    Abstract: A carbonization method of carbonizing precursor fibers that are being conveyed includes carbonization performed using a plurality of carbonization furnaces for heating fibers arranged in the direction in which the fibers are conveyed. The plurality of carbonization furnaces include at least one carbonization furnace that heats the fibers using plasma when the fibers are passing through the inside of the at least one carbonization furnace. A carbon fiber production method includes a carbonization process of carbonizing precursor fibers that are being conveyed. The carbonization process is performed with the above carbonization method.
    Type: Grant
    Filed: July 24, 2014
    Date of Patent: August 29, 2017
    Assignee: TOHO TENAX CO., LTD.
    Inventor: Yoshinori Suzuki
  • Publication number: 20160280871
    Abstract: The present invention provides a heat-curable resin composition, which comprises (1) a heat-curable resin mixture comprising a heat-curable resin (a) and thickener particles (b) and exhibiting a viscosity (150° C.) after having been held at a temperature of 150° C. for 30 seconds that is a viscosity (S), and (2) a curing agent, and is characterized in that the heat-curable resin composition exhibits a lowest viscosity (R) at 80-120° C., the lowest viscosity (R) is 0.1-10 Pa·s, and the viscosity (S) and lowest viscosity (R) satisfy the relationship of formula (1): 5<S/R<200??formula (1).
    Type: Application
    Filed: November 21, 2014
    Publication date: September 29, 2016
    Applicant: TOHO TENAX CO., LTD.
    Inventor: Toru KANEKO
  • Publication number: 20160130732
    Abstract: A carbonization method of carbonizing precursor fibers that are being conveyed includes carbonization performed using a plurality of carbonization furnaces for heating fibers arranged in the direction in which the fibers are conveyed. The plurality of carbonization furnaces include at least one carbonization furnace that heats the fibers using plasma when the fibers are passing through the inside of the at least one carbonization furnace. A carbon fiber production method includes a carbonization process of carbonizing precursor fibers that are being conveyed. The carbonization process is performed with the above carbonization method.
    Type: Application
    Filed: July 24, 2014
    Publication date: May 12, 2016
    Applicant: TOHO TENAX CO., LTD.
    Inventor: Yoshinori SUZUKI
  • Patent number: 9181640
    Abstract: Disclosed is a carbon-fiber chopped strand, and a manufacturing method of the same. The carbon-fiber chopped strand is composed of single filaments composed of 30,000-120,000 carbon fibers, and a sizing agent content 1-10% by weight that bundles the single filaments; the ratio of maximum diameter (Dmax) in the cross section and minimum diameter (Dmin) is 1.0-1.8, a length along a fiber direction is 3-10 mm, and a repose angle of 10-30°.
    Type: Grant
    Filed: February 28, 2011
    Date of Patent: November 10, 2015
    Assignee: TOHO TENAX CO., LTD.
    Inventors: Hiroshi Tsunekawa, Takao Saeki, Akio Yoshida
  • Patent number: 8916310
    Abstract: A conductive sheet comprises an aromatic polyamide pulp, a fluoroplastic fused to the aromatic polyamide pulp, and a carbon-based conductive material; wherein the conductive sheet has a static contact angle of water on a first surface that is greater than the static contact angle of water on a second surface that in the opposite surface to the first surface, and the difference between the static contact angle of water on the first surface and the static contact angle of water on the second surface is 20°-180°; or wherein the injection pressure of water on the first surface of the conductive sheet is less than the injection pressure of water on the second surface that is the opposite surface to the first surface, and the difference between the injection pressure of water on the first surface and the injection pressure of water on the second surface is 20-50 kPa.
    Type: Grant
    Filed: August 24, 2011
    Date of Patent: December 23, 2014
    Assignee: Toho Tenax Co., Ltd.
    Inventors: Kazuma Kurokawa, Tetsuya Akamatsu
  • Publication number: 20130157171
    Abstract: A conductive sheet comprises an aromatic polyamide pulp, a fluoroplastic fused to the aromatic polyamide pulp, and a carbon-based conductive material; wherein the conductive sheet has a static contact angle of water on a first surface that is greater than the static contact angle of water on a second surface that in the opposite surface to the first surface, and the difference between the static contact angle of water on the first surface and the static contact angle of water on the second surface is 20°-180°; or wherein the injection pressure of water on the first surface of the conductive sheet is less than the injection pressure of water on the second surface that is the opposite surface to the first surface, and the difference between the injection pressure of water on the first surface and the injection pressure of water on the second surface is 20-50 kPa.
    Type: Application
    Filed: August 24, 2011
    Publication date: June 20, 2013
    Applicant: TOHO TENAX CO., LTD.
    Inventors: Kazuma Kurokawa, Tetsuya Akamatsu
  • Patent number: 8236273
    Abstract: There is disclosed a method of producing a pre-oxidation fiber in the production of the pre-oxidation fiber by subjecting a polyacrylic precursor fiber to pre-oxidation processing in an oxidizing atmosphere, including shrinking the precursor fiber as a pretreatment of pre-oxidation at a load of 0.58 g/tex or less in the temperature range of 220 to 260° C. under conditions in which the degree of cyclization (I1620/I2240) of the precursor fiber measured by a Fourier transform infrared spectrophotometer (FT-IR) does not exceed 7%, initially-drawing the precursor fiber at a load of 2.7 to 3.5 g/tex in an oxidizing atmosphere at 230 to 260° C. in the ranges of the degree of cyclization of not exceeding 27% and of the density of not exceeding 1.2 g/cm3, and then subjecting the pre-oxidation fiber to pre-oxidation treatment.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: August 7, 2012
    Assignee: Toho Tenax Co., Ltd.
    Inventors: Taro Oyama, Rie Kawahito, Hiroshi Kimura
  • Patent number: 8211537
    Abstract: The present invention discloses a resin composition and a prepreg produced using the resin composition. The resin composition comprises, as essential components: 100 parts by mass of a component (A) which is an epoxy resin; 41 to 80 parts by mass of a component (B) which is thermoplastic resin particles; and 20 to 50 parts by mass (in terms of diaminodiphenylsulfone) of a component (C) which is diaminodiphenylsulfone microencapsulated with a coating agent. The thermoplastic resin particles (B) comprise at least thermoplastic resin particles (B1) having an average particle diameter of 1 to 50 ?m and thermoplastic resin particles (B2) having an average particle diameter of 2 to 100 ?m at a mass ratio of 3:1 to 1:3. The average particle diameter ratio D2/D1 of the average particle diameter D2 of the thermoplastic resin particles (B2) to the average particle diameter D1 of the thermoplastic resin particles (B1) is 2 or more.
    Type: Grant
    Filed: April 11, 2008
    Date of Patent: July 3, 2012
    Assignee: Toho Tenax Co., Ltd.
    Inventors: Yasuyuki Yokoe, Toru Kaneko, Hiroshi Numata, Takeshi Shimada
  • Patent number: 8161607
    Abstract: According to the present invention there is provided a method for opening a fabric, in which warp and weft yarns can be uniformly opened using a simple method without having to alter the fabric weaving procedure. The method is a method for opening a fabric (4) produced by weaving a warp yarn (2) and a weft yarn (3), each of which having a bundled plurality of fiber filaments (1). A contact body (6) is provided to a surface of the fabric (4) with a protective film (5) interposed therebetween, and the contact body (6) is caused to move over the fabric (4) obliquely, and in a relative manner, with respect to the longitudinal direction of the warp yarn (2) or the weft yarn (3), whereby the warp yarn (2) or the weft yarn (3) is spread.
    Type: Grant
    Filed: August 6, 2008
    Date of Patent: April 24, 2012
    Assignees: Arisawa Mfg. Co. Ltd., Toho Tenax Co., Ltd.
    Inventors: Masaaki Hirai, Akihiko Machii
  • Patent number: 8129017
    Abstract: A carbon fiber strand obtained by bundling 20,000-30,000 carbon fibers each having, in the surface thereof, creases which are parallel to the fiber-axis direction. In an examination with a scanning probe microscope, the creases in the carbon fiber surface are apart from each other at a distance of 120-160 nm and have a depth of 12-23 nm, excluding 23 nm. The carbon fibers have an average fiber diameter of 4.5-6.5 nm, specific surface area of 0.9-2.3 m2/g, and density of 1.76 g/cm3 or higher. The carbon strand has a tensile strength of 5,900 MPa or higher and a tensile modulus of 300 GPa or higher. When would on a bobbin at a tension of 9.8 N, the strand on the bobbin has a width of 5.5 mm or larger. When the carbon fiber strand is examined by a strand splitting evaluation method in which the strand is caused to run through three stainless-steel rods while applying a tension of 9.8 N thereto, no strand splitting is observed.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: March 6, 2012
    Assignee: Toho Tenax Co., Ltd.
    Inventors: Hidekazu Yoshikawa, Taro Oyama, Hiroshi Kimura
  • Patent number: 8124228
    Abstract: A carbon fiber strand which is produced by obtaining a solidified-yarn strand by spinning with a spinneret having 20,000-30,000 spinning holes, passing the strand through an interlacing nozzle having an air blowing pressure of 20-60 kPa to obtain precursor fibers, oxidizing them in heated air having a temperature of 200-280° C. to obtain oxidized fibers, subjecting these oxidized fibers to a first carbonization treatment in an inert-gas atmosphere at a temperature of 300-900° C. in which the fibers are firstly stretched in a stretch ratio of 1.03-1.06 and then secondarily stretched in a stretch ratio of 0.9-1.01, subsequently conducting a second carbonization treatment in an inert-gas atmosphere at 1,360-2,100° C., and then conducting a surface oxidization treatment in an aqueous solution of an inorganic acid salt in a quantity of electricity of 20-100 C per g of the carbon fibers.
    Type: Grant
    Filed: August 27, 2008
    Date of Patent: February 28, 2012
    Assignee: Toho Tenax Co., Ltd.
    Inventors: Hidekazu Yoshikawa, Taro Oyama, Hiroshi Kimura
  • Patent number: 8034442
    Abstract: The present invention provides a prepreg made by impregnating a resin composition into a fiber reinforcing material, the resin composition comprising 50 to 60 parts by weight of an aromatic bismaleimide (A), 30 to 40 parts by weight of an alkenylphenol ether compound (B) expressed by a specific general formula, 5 to 15 parts by weight of an alkenyl aromatic comonomer (C), and 1 to 10% by weight of a thermoplastic resin (D) soluble in (B) or (C) based on the total amount of (A), (B) and (C), the aromatic bismaleimide (A) including 90% by weight or more of bismaleimide diphenylmethane, and a composite material having a glass transition temperature of 260 to 350° C. obtained by heat-curing the prepreg.
    Type: Grant
    Filed: January 24, 2008
    Date of Patent: October 11, 2011
    Assignee: Toho Tenax Co., Ltd.
    Inventors: Toru Kaneko, Shusuke Sanai