Patents Assigned to Hart Chemical Limited
  • Low foaming surfactant
    Patent number: 4925988
    Abstract: A novel low foaming non-ionic surfactant having good wetting properties has a molecular weight of about 1700 to about 2300 and the formula:R--O--X--Y--Hwherein R is a primary alkyl group having about 6 to about 10 carbon atoms, X is a random mixture of EO and PO groups containing about 10 to about 12 EO groups and wherein the mole ratio of EO:PO groups is about 4:1, and Y is a PO block containing about 15 to about 25 PO groups, preferably about 21 to about 25.
    Type: Grant
    Filed: August 17, 1988
    Date of Patent: May 15, 1990
    Assignee: Hart Chemical Limited
    Inventors: Brigitte H. Licht, Roger T. Bentley, Frederick S. Schell
  • Production of highly-dispersible water-soluble polymers
    Patent number: 4874827
    Abstract: The water dispersibility of water-soluble vinyl polymers, for example, polyacrylamides, is improved by incorporating a suitable surfactant in the monomer mixture from which the polymer is formed. The polymerization is effected by an initial phase of ultraviolet radiation-induced free radical polymerization until the monomer mix achieves the temperature at which chemically-induced free radical polymerization commences and then a terminal phase of chemically-induced free radical polymerization.
    Type: Grant
    Filed: August 24, 1988
    Date of Patent: October 17, 1989
    Assignee: Hart Chemical Limited
    Inventors: Ratana Kanluen, Brigitte H. Licht
  • Water-emulsifiable defoamer composition
    Patent number: 4088601
    Abstract: Defoamer compositions, from which particulate inorganic solids are substantially absent, are described for use in hot and cold stock pulp mill and paper mill applications. The compositions are water-emulsifiable to form stable emulsions for ease of application in use. The composition contains low viscosity mineral oils, an aliphatic diamide, silicone oil and an ethoxylated alkyl substituted phenol.
    Type: Grant
    Filed: November 11, 1974
    Date of Patent: May 9, 1978
    Assignee: Hart Chemical Limited
    Inventors: Hugh J. S. Shane, Frederick S. Schell
  • Water-dispersible defoamer composition
    Patent number: 4024072
    Abstract: Water-dispersible defoamer compositions comprise an intimate blend of a mixture of defoaming components and at least one emulsifier to impart water-dispersibility to the composition. The defoaming components include a monoester of an alkenylated succinic acid, a particular organo-phosphorus compound and a silicone oil. The defoamer compositions have particular use in pulp mill defoaming compositions.
    Type: Grant
    Filed: February 18, 1976
    Date of Patent: May 17, 1977
    Assignee: Hart Chemical Limited
    Inventors: Hugh J. S. Shane, Frederick S. Schell, Mohammad A. Kasem
  • Bottle
    Patent number: D273661
    Type: Grant
    Filed: December 2, 1981
    Date of Patent: May 1, 1984
    Assignee: Hart Chemical Limited
    Inventor: Fredi Widmer