Patents Assigned to W. R. Grace AB
  • Method for controlling pitch on a paper-making machine
    Patent number: 5223097
    Abstract: A method for the control of pitch in an aqueous system used in pulp or paper making is disclosed which comprises adding to the system, or to the pulp making or paper making machinery, a water soluble polymer derived from (a) an epihalohydrin, a diepoxide or a precursor of an epihalohydrin or diepoxide, (b) an alkyl amine having a functionality with respect to an epihalohydrin of 2 and (c) an amine which has a functionality with respect to an epihalohydrin greater than 2 and which does not possess any carbonyl groups.
    Type: Grant
    Filed: June 20, 1989
    Date of Patent: June 29, 1993
    Assignee: W. R. Grace AB
    Inventor: Thord G. G. Hassler
  • Water soluble thermosetting resin, process for its production, paper sizing composition and paper sizing process
    Patent number: 4895621
    Abstract: A water soluble thermosetting resin useful as a promoter for paper sizing is described. Polyallylamine or a modified polyallyamine is reacted with epichlorohydrin and/or formaldehyde. The formaldehyde may be reacted with the polyallylamine in the presence of dicyandiamide, urea or an ammonium salt or mixtures thereof.
    Type: Grant
    Filed: November 18, 1986
    Date of Patent: January 23, 1990
    Assignee: W. R. Grace AB
    Inventor: Thord G. Hassler
  • Novel amino resins useful in sizing paper and their use
    Patent number: 4847315
    Abstract: A water-soluble, thermosetting resin comprising units derived from tris(2-aminoethyl)amine, and preferably units derived from dicyandiamide and/or epichlorohydrin, is useful as an accelerator in paper sizing, e.g. using an alkyl ketene dimer.
    Type: Grant
    Filed: June 3, 1987
    Date of Patent: July 11, 1989
    Assignee: W. R. Grace AB
    Inventor: Thord G. G. Hassler