Patents by Inventor George M. Crews

George M. Crews 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: 5795507
    Abstract: Spherical porous polymer pigment beads of melamine formaldehyde resin with uniform diameter were prepared by a water-in-oil emulsion polymerization of colored methylolmelamine aqueous solution. The dyes combined with methylolmelamine to give an excellent hue stability. The pigmented melamine formaldehyde beads (PMFB) with mean size of 3-6 micron as an organic pigment showed excellent weather and heat stability, chemical resistant properties and disperability in an application medium.
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: August 18, 1998
    Assignee: Melamine Chemicals, Inc.
    Inventors: George M. Crews, Ji Shen
  • Patent number: 5254665
    Abstract: Ammeline-melamine-formaldehyde resins (AMFR) containing from 5-100% ammeline were synthesized by the polymerization of the sodium salt of ammeline, which must be made in advance, melamine, and formaldehyde in basic medium (pH=9.2-10.0). In this copolymerization, it is possible to make uniform random AMFR resins with any mole ratio of ammeline salt to melamine. Preferably the AMFR resin will contain from 5-10% ammeline. As an "ionomer" or a "polyelectrolyte," both the solid and solution properties of these resins (such as melting temperature, solubility, solution stability, etc.) depended directly on the mole ratio of ammeline to melamine and formaldehyde, and/or on the pH value of the medium in which the AMFR resin was present. The pH value controlled the ammeline rings/ammeline's salt groups and also the ratio of unprotonated to protonated amino groups on both the melamine and ammeline rings.
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: October 19, 1993
    Assignee: Melamine Chemicals, Inc.
    Inventors: George M. Crews, Shen Ji, Charles U. Pittman, Jr., Ruicheng Ran
  • Patent number: 5120821
    Abstract: A process of producing melamine formaldehyde resins using crude or impure melamine is described. The process using the impure or crude melamine includes the control of the pH within the range of from about 8 to 10, and preferably 9 to 9.2 during at least the initial stages of the formaldehyde/melamine reaction. The pH control provides resins having commercially acceptable characteristics, with the cook times of the resin formation also being commercially acceptable.
    Type: Grant
    Filed: February 22, 1991
    Date of Patent: June 9, 1992
    Assignee: Melamine Chemicals, Inc.
    Inventors: George M. Crews, Shen Ji
  • Patent number: 4832728
    Abstract: Relates to a fertilizer product in granular form, to processes for making and using it. The granules have strength, sizes and weights suitable for mechanical dispensing and application to and into the soil. These granules combine particles of a nitrogen source of poor solubility in pH 7 water at 20.degree. C., that converts slowly to a useful form, together with a binder that holds these fine particles together.
    Type: Grant
    Filed: September 18, 1985
    Date of Patent: May 23, 1989
    Assignee: Melamine Chemicals, Inc.
    Inventors: G. Graham Allan, Donald E. Freepons, George M. Crews
  • Patent number: 4560400
    Abstract: Relates to a fertilizer product in granular form, to processes for making and using it. The granules have strength, sizes and weights suitable for mechanical dispensing and application to and into the soil. These granules combine particles of a nitrogen source of poor solubility in pH 7 water at 20.degree. C., that converts slowly to a useful form, together with a binder that holds these fine particles together.
    Type: Grant
    Filed: November 17, 1983
    Date of Patent: December 24, 1985
    Assignee: Melamine Chemicals, Inc.
    Inventors: G. Graham Allan, Donald E. Freepons, George M. Crews
  • Patent number: 4421545
    Abstract: This invention relates to an improved annealing process for preparing melamine-urea fertilizer granular agglomerates having increased crush strength.
    Type: Grant
    Filed: January 13, 1982
    Date of Patent: December 20, 1983
    Assignee: Melamine Chemicals, Inc.
    Inventor: George M. Crews