Patents by Inventor Masakazu Yokoi

Masakazu Yokoi 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).

  • Ink composition for oil marking pen
    Patent number: 6039795
    Abstract: An ink composition for an oil marking pen is provided which comprises a coloring agent, an organic polar solvent, an oil-soluble resin and an organically modified silicone as principal components thereof. The organically modified silicone is selected from dimethyl silicone, alkyl-modified silicones, polyether-modified silicones such as a polyoxypropylene modified silicone and the like, and is contained in the ink composition in a proportion of 0.005 wt % to 10 wt %. The organic polar solvent is selected from alcohol solvents and glycol ether solvents. The oil-soluble resin is selected from ketone resins, phenol resins, xylene resins, rosin resins, styrene-organic acid copolymers and polyacrylates. The ink composition of the present invention is excellent in the ink film fixability when applied on a nonabsorbent surface such as a metal surface or a plastic surface, and suitable for oil marking pens.
    Type: Grant
    Filed: December 8, 1997
    Date of Patent: March 21, 2000
    Assignee: Sakura Color Products Corporation
    Inventors: Hidetoshi Fukuo, Masakazu Yokoi
  • Ink composition for marking pen
    Patent number: 5762694
    Abstract: An ink composition according to the present invention includes (1) a leafing type fine metal powder having a median particle size of from about 4 .mu.m to about 11 .mu.m, the powder being present in an amount, relative to the total amount of the ink composition, within the range of from about 10% to about 38% by weight, the powder being selected from a copper alloy, aluminum, copper, or zinc whose surface is treated by a saturated fatty acid having 16 to 22 carbon atoms, or salts thereof. The ink composition further includes (2) a petroleum resin having iodine value of not more than 30 (g/100 g), whereby the resin is present in an amount, relative to the total amount of the ink composition, within the range of from about 10% to about 30% by weight; (3) at least two kinds of hydrocarbon solvents, whereby the solvents are present in an amount, relative to the total amount of the ink composition, within the range of from about 32% to about 80% by weight.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: June 9, 1998
    Assignee: Sakura Color Products Corporation
    Inventors: Masakazu Yokoi, Hirofumi Yamasaki, Yasuji Okuda
  • Fluorescent ink composition for use in marking pens
    Patent number: 5698614
    Abstract: A fluorescent ink composition which comprises:(a) an organic solvent which comprises propylene glycol monomethyl ether as a solvent:(b) a solution type fluorescent pigment dissolved in the organic solvent; and(c) a ketone resin.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: December 16, 1997
    Assignee: Sakura Color Products Corporation
    Inventors: Hiroaki Ueda, Masakazu Yokoi, Yasushi Okuda