Patents by Inventor Maria I. Villarreal

Maria I. Villarreal 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).

  • Preparation of 4,4'-dihydroxy-alpha'-dialkylstilbenes and 4, 4'-dihydroxy-alpha'-dialkylstilbenes
    Patent number: 5475155
    Abstract: 4,4'-Dihydroxy-alpha-alkylstilbenes of high purity are prepared by reacting at a temperature of from about -20.degree. C. to about 20.degree. C. a mixture of (1) at least one alpha-haloketone, (2) at least one phenolic hydroxyl-containing compound or alkoxy-containing aromatic compound, and (3) at least one strong protonic acid or Lewis acid; such that the mole ratio of phenolic hydroxyl-containing compound or alkoxy-containing aromatic compound:alpha-haloketone(s) is from 0.1:1 to 1.9:1, and the mole ratio of phenolic hydroxyl-containing compound or alkoxy-containing aromatic compound:alpha-haloketone(s):strong protonic acid or Lewis acid is from about 0.1:1:0.0026 to about 1.9:1:0.95. The high purity 4,4'-dihydroxy-alpha-alkylstilbenes are useful for the advancement of epoxy resins, for the preparation of phenoxy resins and for the preparation of epoxy resins.
    Type: Grant
    Filed: January 18, 1995
    Date of Patent: December 12, 1995
    Assignee: The Dow Chemical Company
    Inventors: Robert E. Hefner, Jr., Maria I. Villarreal, David A. Carr
  • Preparation of 4,4'-dihydroxy-alpha-alkylstilbenes and 4,4'-dihydroxy-alpha, alpha'-dialkylstilbenes
    Patent number: 5414150
    Abstract: 4,4'-Dihydroxy-alpha-alkylstilbenes of high purity are prepared by reacting at a temperature of from about -20.degree. C. to about 20.degree. C. a mixture of (1) at least one alpha-haloketone, (2) at least one phenolic hydroxyl-containing compound or alkoxy-containing aromatic compound, and (3) at least one strong protonic acid or Lewis acid; such that the mole ratio of phenolic hydroxyl-containing compound or alkoxy-containing aromatic compound:alpha-haloketone(s) is from 0.1:1 to 1.9:1, and the mole ratio of phenolic hydroxyl-containing compound or alkoxy-containing aromatic compound:alpha-haloketone(s):strong protonic acid or Lewis acid is from about 0.1:1:0.0026 to about 1.9:1:0.95. The high purity 4,4'-dihydroxy-alpha-alkylstilbenes are useful for the advancement of epoxy resins, for the preparation of phenoxy resins and for the preparation of epoxy resins.
    Type: Grant
    Filed: December 3, 1993
    Date of Patent: May 9, 1995
    Assignee: The Dow Chemical Company
    Inventors: Robert E. Hefner, Jr., Maria I. Villarreal, David A. Carr