Patents by Inventor Robert D. Dworkin

Robert D. Dworkin 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: 4279807
    Abstract: The combination of a conventional antimony- or bismuth-containing heat stabilizers with certain aromatic esters or aryloxides containing boron, phosphorus, silicon, antimony, tin or zinc interacts synergistically to provide an unexpectedly high level of heat stability to halogen-containing polymers such as polyvinyl chloride (PVC). In addition the aromatic ester or aryloxide inhibits spontaneous degradation of the heat stabilizing component in the presence of heat and/or light.
    Type: Grant
    Filed: December 13, 1979
    Date of Patent: July 21, 1981
    Assignee: M&T Chemicals Inc.
    Inventor: Robert D. Dworkin
  • Patent number: 4254017
    Abstract: This invention relates to novel organotin compounds containing at least one sulfur atom that is bonded exclusively to tin or to tin and hydrogen. The compounds are derivatives of mercaptoalkanols, which are present as the free alcohols, as esters of polycarboxylic acids, esters of acids containing specified non-metallic elements or as alkoxides of specified metallic elements. The compounds are effective catalysts for a variety of reactions and impart heat stability to halogen-containing resins.
    Type: Grant
    Filed: November 13, 1978
    Date of Patent: March 3, 1981
    Assignee: M&T Chemicals Inc.
    Inventors: Robert D. Dworkin, William A. Larkin
  • Patent number: 4231895
    Abstract: The combination of a conventional antimony--or bismuth-containing heat stabilizers with certain aromatic esters or aryloxides containing boron, phosphorus, silicon, antimony, tin or zinc interacts synergistically to provide an unexpectedly high level of heat stability to halogen-containing polymers such as polyvinyl chloride (PVC). In addition the aromatic ester or aryloxide inhibits spontaneous degradation of the heat stabilizing component in the presence of heat and/or light.
    Type: Grant
    Filed: January 2, 1979
    Date of Patent: November 4, 1980
    Assignee: M & T Chemicals Inc.
    Inventor: Robert D. Dworkin
  • Patent number: 4187239
    Abstract: Organotin derivatives of mercaptoalcohol esters that correspond to the general formula ##STR1## wherein R and R' are hydrocarbon and m is 2 or 3, are prepared by sequentially reacting a monoorganotin trihalide with stoichiometric amounts of a base, a mercaptoalcohol, an alkali metal sulfide or disulfide and a carboxylic acid or an ester thereof. The present method offers advantages over the prior art, which teaches reacting an esterified mercaptoalcohol with an organotin halide, oxide or organostannoic acid. Compounds wherein R' is n-heptyl are unique in that they do not exhibit the disagreeable odor that characterizes this class of compounds.
    Type: Grant
    Filed: July 20, 1978
    Date of Patent: February 5, 1980
    Assignee: M&T Chemicals Inc.
    Inventor: Robert D. Dworkin
  • Patent number: 4124618
    Abstract: Organotin derivatives of mercaptoalcohol esters that correspond to the general formula ##STR1## wherein R and R' are hydrocarbon, m is 2 or 3, and p is 1 or 2 are prepared by sequentially reacting a quantity of a monoorganotin trihalide, a diorganotin dihalide or an equimolar mixture of a mono- and a diorganotin halide containing n moles of halogen with n-2 equivalent weights of a base, n-2 moles of a mercaptoalcohol, 0.5 mole of an alkali metal sulfide when p is 1 or an alkali metal disulfide when p is 2, for every mole of tin present and n-2 moles of an carboxylic acid or ester thereof. The present method offers advantages over the prior art, which teaches reacting an esterified mercaptoalcohol with an organotin halide, oxide or organostannoic acid. Compounds wherein R' is n-heptyl are unique in that they do not exhibit the disagreeable odor that characterizes this class of compounds.
    Type: Grant
    Filed: November 2, 1976
    Date of Patent: November 7, 1978
    Assignee: M&T Chemicals Inc.
    Inventors: Robert D. Dworkin, Adam J. Ejk
  • Patent number: 4104292
    Abstract: Organotin derivatives of mercaptoalcohol esters corresponding to the general formula ##STR1## WHEREIN R and R' are hydrocarbon, m is 2 or 3 and q is 1 or 2 are prepared by reacting a mercaptoalcohol of the formula HS(CH.sub.2).sub.m OH with a diorganotin oxide, organostannoic acid or an anhydride of said acid in an aqueous medium and subsequently esterifying the reaction product with the desired carboxylic acid, R'COOH, or an ester thereof. The present method offers advantages over the prior art, which teaches reacting an esterified mercaptoalcohol with an organotin compound. Compounds wherein R' is n-heptyl are unique in that they do not exhibit the disagreeable odors that characterize this class of compounds.
    Type: Grant
    Filed: November 2, 1976
    Date of Patent: August 1, 1978
    Assignee: M&T Chemicals Inc.
    Inventors: Robert D. Dworkin, Adam J. Ejk
  • Patent number: 3953385
    Abstract: Cellular vinyl chloride polymers are prepared in the presence of a blowing agent and a diorganotin dimercaptide such as di-n-butyltin bis(dodecyl mercaptide). These organotin compounds are unique in that they activate the blowing agent to achieve maximum gas evolution at conventional processing temperatures while imparting a superior level of heat stability to the polymer. The dimercaptide is preferably employed in combination with a specified organotin derivative of a carboxylic acid, alcohol or phenol and/or metal salts of carboxylic acids containing between 4 and 18 carbon atoms wherein the metal is selected from Group IIB of the Periodic Table.
    Type: Grant
    Filed: December 5, 1974
    Date of Patent: April 27, 1976
    Assignee: M&T Chemicals Inc.
    Inventors: Robert D. Dworkin, Adam J. Ejk