Patents by Inventor Takayuki Ikai

Takayuki Ikai 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: 11654711
    Abstract: A writing tool includes a refill having an ink reservoir tube formed to be a straight cylinder whose wall thickness is less than 0.56 mm; and a writing tip or a relay member holding the writing tip attached to a first end of the ink reservoir tube, wherein the refill is detachably attached to a barrel, wherein in the refill, amounting strength between the writing tip or the relay member holding the writing tip and the ink reservoir tube is set higher than a mounting strength between the barrel and a connecting portion of the ink reservoir tube. There is provided a writing tool that can prevent the occurrence of a problem such as leakage of ink at a time of replacement of refills and perform replacement of refills smoothly.
    Type: Grant
    Filed: June 17, 2019
    Date of Patent: May 23, 2023
    Assignee: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Takayuki Ikai, Seiichi Maruyama, Kiyoshi Iwamoto
  • Publication number: 20230072944
    Abstract: A coloring tablet may have excellent solubility and redispersibility and a water-based ink composition for a writing instrument. Such a coloring tablet may contain at least a colorant and a dispersing agent. The dispersing agent may include a hydroxide neutralization product of an (meth)acrylic resin, a hydroxide neutralization product of a styrene-maleic acid copolymer resin, a polyoxyethylene-based surfactant, an alkyl condensed ring sulfonate, an amine ethylene oxide propylene oxide adduct, and/or a isobutylene-based polymer.
    Type: Application
    Filed: August 4, 2022
    Publication date: March 9, 2023
    Applicant: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Tatsuya MIZOGUCHI, Takayuki IKAI
  • Publication number: 20220017760
    Abstract: Provided are an oil-based ink composition for writing utensils, a writing utensil using the same, and an airbrush unit using the same. The oil-based ink composition for writing utensils has good writing properties on writing surfaces of various materials and improved scratch resistance to scratches repeated or to scratches with stronger force on a marking after writing. The subject oil-based ink composition for writing utensils contains at least an aluminum pigment, a colorant, a resin, an organic solvent, and a polydimethylsiloxane, the polydimethylsiloxane having polyether-modifying groups at both ends, and a total number of hydroxyl groups on the polyether-modifying groups being 3 or greater.
    Type: Application
    Filed: November 19, 2019
    Publication date: January 20, 2022
    Applicant: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Takayuki IKAI, Yumiko HARUHARA
  • Patent number: 11135868
    Abstract: A refill for writing implements has an ink reservoir tube (1) made of resin material and formed to be a straight cylinder and a writing tip (2) attached to one end of the ink reservoir tube (1), and a value of an expression of D4?(D?2t)4 is selected to be 45 or greater, where D denotes an outer diameter of the ink reservoir tube (1) and t denotes a thickness of the ink reservoir tube (1). It is possible to secure the necessary storage amount of ink in the ink reservoir tube (1) without increasing the outer diameter thereof, and is also possible to provide a refill for a writing implement and a writing implement which allow one to keep writing comfortably without feeling of discomfort in writing.
    Type: Grant
    Filed: March 19, 2018
    Date of Patent: October 5, 2021
    Assignee: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventor: Takayuki Ikai
  • Publication number: 20210178803
    Abstract: A writing tool includes a refill having an ink reservoir tube formed to be a straight cylinder whose wall thickness is less than 0.56 mm; and a writing tip or a relay member holding the writing tip attached to a first end of the ink reservoir tube, wherein the refill is detachably attached to a barrel, wherein in the refill, amounting strength between the writing tip or the relay member holding the writing tip and the ink reservoir tube is set higher than a mounting strength between the barrel and a connecting portion of the ink reservoir tube. There is provided a writing tool that can prevent the occurrence of a problem such as leakage of ink at a time of replacement of refills and perform replacement of refills smoothly.
    Type: Application
    Filed: June 17, 2019
    Publication date: June 17, 2021
    Applicant: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Takayuki IKAI, Seiichi MARUYAMA, Kiyoshi IWAMOTO
  • Patent number: 10569596
    Abstract: A refill for a writing tool includes an ink containing tube that is made from a resin material and formed in a straight cylindrical shape, and a writing tip that is attached to an end of the ink containing tube. A press-fit portion, formed at the end of the ink containing tube, has a thickness being made thickened toward an inner circumferential surface and has an opening hole penetrating in an axial direction at a central portion of the press-fit portion. The writing tip or a relay member supporting the writing tip is press-fitted and attached to the press-fit portion. The refill for a writing tool can ensure a necessary and sufficient amount of ink stored without expanding an outer diameter of the ink containing tube, and sufficiently secure mechanical strength of an end portion, and a writing tool using the same can be provided.
    Type: Grant
    Filed: October 6, 2016
    Date of Patent: February 25, 2020
    Assignee: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Takayuki Ikai, Seiichi Takigawa, Naohiro Katou, Takanori Shindou
  • Publication number: 20190337323
    Abstract: A refill for writing implements has an ink reservoir tube (1) made of resin material and formed to be a straight cylinder and a writing tip (2) attached to one end of the ink reservoir tube (1), and a value of an expression of D4?(D?2t)4 is selected to be 45 or greater, where D denotes an outer diameter of the ink reservoir tube (1) and t denotes a thickness of the ink reservoir tube (1). It is possible to secure the necessary storage amount of ink in the ink reservoir tube (1) without increasing the outer diameter thereof, and is also possible to provide a refill for a writing implement and a writing implement which allow one to keep writing comfortably without feeling of discomfort in writing.
    Type: Application
    Filed: March 19, 2018
    Publication date: November 7, 2019
    Applicant: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventor: Takayuki Ikai
  • Publication number: 20180236807
    Abstract: A refill for a writing tool includes an ink containing tube that is made from a resin material and formed in a straight cylindrical shape, and a writing tip that is attached to an end of the ink containing tube. A press-fit portion, formed at the end of the ink containing tube, has a thickness being made thickened toward an inner circumferential surface and has an opening hole penetrating in an axial direction at a central portion of the press-fit portion. The writing tip or a relay member supporting the writing tip is press-fitted and attached to the press-fit portion. The refill for a writing tool can ensure a necessary and sufficient amount of ink stored without expanding an outer diameter of the ink containing tube, and sufficiently secure mechanical strength of an end portion, and a writing tool using the same can be provided.
    Type: Application
    Filed: October 6, 2016
    Publication date: August 23, 2018
    Applicant: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Takayuki Ikai, Seiichi Takigawa, Naohiro Katou, Takanori Shindou
  • Publication number: 20100297901
    Abstract: The present invention relates to a coloring composition for preventing see-through of cloth which comprises, on the basis of the total mass of the composition, a pigment in an amount ranging from 0.002% by mass to 1% by mass; a polymer particulate dispersion; and water. The present invention can thus provide the cloth which can prevent any see-through of the color of the underlying layer without causing any color-see-through phenomenon even if the cloth is white or light-colored one, and which can show excellent fastness while maintaining hand and feel peculiar to the original cloth irrespective of the material of the cloth used.
    Type: Application
    Filed: October 25, 2007
    Publication date: November 25, 2010
    Applicant: MITSUBISHI PENCIL COMPANY, LIMITED
    Inventors: Takayuki Ikai, Shigeru Miyazaki, Tadashi Kamagata
  • Patent number: 7381754
    Abstract: An ink composition comprising at least one dye represented by one of the following chemical structural formulae and an anthraquinone-based pigment as coloring materials, an alcohol or an ether as a solvent, and a resin. In a preferred embodiment, a triarylmethane-based dye is used in combination or polyvinylbutyral is contained as the resin. wherein A is a tertiary or quaternary ammonium ion group.
    Type: Grant
    Filed: July 19, 2002
    Date of Patent: June 3, 2008
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Shuuji Ichikawa, Takayuki Ikai
  • Patent number: 7311459
    Abstract: A follower for a nonaqueous ballpoint pen, comprising at least one poly-?-olefin which is a synthetic oil having a viscosity of 200 mPa·s or more at 40° C., wherein the total amount of poly-?-olefins is 80 mass % or more of all components, the viscosity at 40° C. is from 1,000 to 30,000 mPa·s, and the shear-thinning index at a shear rate of 1 to 10/s is 0.95 or more. A follower for a nonaqueous ballpoint pen can be used also for a nonaqueous ballpoint pen using a solvent having a high vapor pressure and causes no problem even when the follower is mounted in an ink reservoir tube with strong tube resistance having an inner diameter of 2.8 mm or less.
    Type: Grant
    Filed: April 16, 2004
    Date of Patent: December 25, 2007
    Assignee: Mitsubishi Pencil Kabushiki Kaisha
    Inventors: Takayuki Ikai, Shuji Ichikawa
  • Publication number: 20070020031
    Abstract: A follower for a nonaqueous ballpoint pen, comprising at least one poly-?-olefin which is a synthetic oil having a viscosity of 200 mPa·s or more at 40° C., wherein the total amount of poly-?-olefins is 80 mass % or more of all components, the viscosity at 40° C. is from 1,000 to 30,000 mPa·s, and the shear-thinning index at a shear rate of 1 to 10/s is 0.95 or more. According to the present invention, a follower for a nonaqueous ballpoint pen is provided, which can be used also for a nonaqueous ballpoint pen using a solvent having a high vapor pressure and causes no problem even when the follower is mounted in an ink reservoir tube with strong tube resistance having an inner diameter of 2.8 mm or less. Also, a nonaqueous ballpoint pen is provided, which comprises this follower for a nonaqueous ballpoint pen and a nonaqueous ballpoint pen ink using a solvent having a high vapor pressure and in which the inner diameter of the ink reservoir tube is 2.8 mm or less.
    Type: Application
    Filed: April 16, 2004
    Publication date: January 25, 2007
    Applicant: MITSUBISHI PENCIL KABUSHIKI KAISHA
    Inventors: Takayuki Ikai, Shuji Ichikawa
  • Patent number: 6945726
    Abstract: A refill for an oil-based ink ballpoint pen which inhibits starving at the beginning of writing and protects a pen point and which inhibits an ink solvent from absorbing moisture from the outside and volatilizing with the passage of time and is excellent in making writing feeling soft and smooth. The refill for an oil-based ink ballpoint pen includes a volatilization-inhibiting seal member, for example, a sealing coat prepared by melting and solidifying an olefin base thermoplastic sticking agent is formed at the point part a tip of a refill for an oil-based ink ballpoint pen charged with a volatile oil-based ink having a specific physical property. The refill can be charged into a defined oil-based ink ballpoint pen.
    Type: Grant
    Filed: September 8, 2004
    Date of Patent: September 20, 2005
    Assignee: Mitsubishi Pencil Co. Ltd.
    Inventors: Syuji Ichikawa, Takayuki Ikai, Miyuki Shouji, Daisen Katou, Takeshi Kobayashi
  • Publication number: 20050123341
    Abstract: A refill for an oil-based ink ballpoint pen which inhibits starving at the beginning of writing and protects a pen point and which inhibits an ink solvent from absorbing moisture from the outside and volatilizing with the passage of time and is excellent in making writing feeling soft and smooth. The refill for an oil-based ink ballpoint pen includes a volatilization-inhibiting seal member, for example, a sealing coat prepared by melting and solidifying an olefin base thermoplastic sticking agent is formed at the point part a tip of a refill for an oil-based ink ballpoint pen charged with a volatile oil-based ink having a specific physical property. The refill can be charged into a defined oil-based ink ballpoint pen.
    Type: Application
    Filed: September 8, 2004
    Publication date: June 9, 2005
    Applicant: Mitsubishi Pencil Co., Ltd.
    Inventors: Syuji Ichikawa, Takayuki Ikai, Miyuki Shouji, Daisen Katou, Takeshi Kobayashi
  • Patent number: 6830611
    Abstract: An ink composition comprising at least one triarylmethane-based dye as a coloring material, an alcohol having 2 or more carbon atoms, a polyhydric alcohol or a glycol ether as a solvent, and a resin which can dissolve in the solvent, the triarylmethane-based dye comprising a compound represented by the following formula: [C(—Ar—Y)3]A wherein each Ar is independently an aryl group substituted, or not substituted, by a halogen or an alkyl group, each Y is independently a diethylamino group or hydrogen, provided that at least two Y are a diethylamino group, A is a halogen or an organic acid group, and A is charge-balanced to the residue.
    Type: Grant
    Filed: May 17, 2002
    Date of Patent: December 14, 2004
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Shuuji Ichikawa, Takayuki Ikai
  • Publication number: 20030134937
    Abstract: An ink composition comprising at least one dye represented by one of the following chemical structural formulae and an anthraquinone-based pigment as coloring materials, an alcohol or an ether as a solvent, and a resin. In a preferred embodiment, a triarylmethane-based dye is used in combination or polyvinylbutyral is contained as the resin.
    Type: Application
    Filed: July 19, 2002
    Publication date: July 17, 2003
    Applicant: MITSUBISHI PENCIL CO., LTD.
    Inventors: Shuuji Ichikawa, Takayuki Ikai
  • Publication number: 20030075074
    Abstract: An ink composition comprising at least one triarylmethane-based dye as a coloring material, an alcohol having 2 or more carbon atoms, a polyhydric alcohol or a glycol ether as a solvent, and a resin which can dissolve in the solvent, the triarylmethane-based dye comprising a compound represented by the following formula: [C(—Ar—Y)3]A wherein each Ar is independently an aryl group substituted, or not substituted, by a halogen or an alkyl group, each Y is independently a diethylamino group or hydrogen, provided that at least two Y are a diethylamino group, A is a halogen or an organic acid group, and A is charge-balanced to the residue.
    Type: Application
    Filed: May 17, 2002
    Publication date: April 24, 2003
    Inventors: Shuuji Ichikawa, Takayuki Ikai
  • Patent number: 6441061
    Abstract: A additive for an oil based ink for a ball point pen containing at least one or plural kinds of organic solvents, a resin and an inorganic fine particle thickener, wherein the additive has a viscosity of 1000 mPa·s or more at a shear rate of 5/s and at 0° C. and a viscosity of 50000 mPa·s or less at a shear rate of 5/s and at 50° C., and has an absorbance of from 0.01 to 5 at a wavelength of 900 nm when a cell is 1 cm long. This additive is added to an oil based ink for a ball point pen such that an amount of the additive becomes 0.1 to 30% by weight based on the total ink.
    Type: Grant
    Filed: February 16, 2001
    Date of Patent: August 27, 2002
    Assignee: Mitsubishi Pencil Kabushiki Kaisha
    Inventor: Takayuki Ikai
  • Patent number: 5942027
    Abstract: An ink for a ball point pen contains at least one or plural kinds of organic solvents, colorants and resins and further contains fine particle silica having a primary average particle diameter of 7 to 40 nm and a specific surface area (BET method) of 50 to 380 m.sup.2 /g. The ink for a ball point pen is prevented from leaking out of the pen tip, is not damaged smooth writing feeling and does not cause clogging at the pen tip.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: August 24, 1999
    Assignee: Mitsubishi Pencil Kabushiki Kaisha
    Inventors: Takayuki Ikai, Misao Oyama