Patents by Inventor Hiroaki TAMAGAKI

Hiroaki TAMAGAKI 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).

  • Publication number: 20210171663
    Abstract: To provide cellulose acetate that exhibits excellent hue even though it is produced by using low grade pulp having a particularly low ?-cellulose content, and also achieves excellent moldability and excellent production efficiency of a molded article. A method for producing cellulose acetate is also provided, the method that can provide cellulose acetate with excellent stable productivity and production efficiency without passing through steps such as extraction. The cellulose acetate of the present invention includes xylose with a molar content rate of greater than 7.0 mol % and not greater than 15 mol % in a sum of molar contents of xylose, mannose, and glucose; and has a hue of not less than 0.60 cm?1 and less than 0.80 cm?1 at a wavelength of 430 nm by absorptiometry; and a 6% viscosity of not greater than 160 mPa·s.
    Type: Application
    Filed: September 29, 2017
    Publication date: June 10, 2021
    Applicant: DAICEL CORPORATION
    Inventors: Akihiro KUWANA, Hiroaki TAMAGAKI
  • Publication number: 20210079561
    Abstract: An object is to mitigate clogging of spinneret holes which occurs as the passage of spinning time even though cellulose acetate has a small titanium oxide content or contains no titanium oxide and to prevent a reduction in pressure drop of a cellulose acetate band. A cellulose acetate fiber, in which a titanium oxide content is not greater than 0.05 wt. %, a calcium content is not greater than 20 ppm, and a magnesium content is not less than 30 ppm.
    Type: Application
    Filed: July 10, 2019
    Publication date: March 18, 2021
    Applicant: DAICEL CORPORATION
    Inventors: Takehiro MATSUMOTO, Hiroaki TAMAGAKI, Keita TAKAHASHI, Takahiko SHIMA
  • Publication number: 20210017296
    Abstract: An object is to provide a cellulose acetate remarkably good in hue even when a low-quality pulp is used. A method for producing the cellulose acetate includes a step (1) of crushing a wood pulp, a step (2) of bringing the crushed wood pulp into contact with acetic acid to subject the pulp to pretreat the wood pulp, a step (3) of causing the wood pulp to react with acetic anhydride after the pretreatment to acetylate the pulp, a step (4) of hydrolyzing the cellulose acetate, which is yielded by the acetylation, and a step (5) of precipitating the cellulose acetate, an acetylation degree of which is adjusted by the hydrolysis. In the hydrolyzing step (4), in a hydrolysis reaction system, a concentration of oxygen is set to 3% or less.
    Type: Application
    Filed: October 1, 2020
    Publication date: January 21, 2021
    Applicant: DAICEL CORPORATION
    Inventors: Akihiro KUWANA, Hiroaki TAMAGAKI
  • Publication number: 20180282434
    Abstract: An object is to provide a cellulose acetate remarkably good in hue even when a low-quality pulp is used. A method for producing the cellulose acetate includes a step (1) of crushing a wood pulp, a step (2) of bringing the crushed wood pulp into contact with acetic acid to subject the pulp to pretreat the wood pulp, a step (3) of causing the wood pulp to react with acetic anhydride after the pretreatment to acetylate the pulp, a step (4) of hydrolyzing the cellulose acetate, which is yielded by the acetylation, and a step (5) of precipitating the cellulose acetate, an acetylation degree of which is adjusted by the hydrolysis. In the hydrolyzing step (4), in a hydrolysis reaction system, a concentration of oxygen is set to 3% or less.
    Type: Application
    Filed: October 5, 2016
    Publication date: October 4, 2018
    Applicant: DAICEL CORPORATION
    Inventors: Akihiro KUWANA, Hiroaki TAMAGAKI