Patents by Inventor Michael Stumpp

Michael Stumpp 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).

  • Process for the preparation of bis(4-chlorophenyl) sulfone
    Patent number: 5082973
    Abstract: A process for the preparation of bis(4-chlorophenyl) sulfone, wherein sulfur trioxide, dimethyl sulfate and chlorobenzene are reacted with each in a single reaction at a temperature of from 50.degree. to 100.degree. C.
    Type: Grant
    Filed: January 12, 1990
    Date of Patent: January 21, 1992
    Assignee: BASF Aktiengesellschaft
    Inventors: Michael Stumpp, Peter Neumann, Heinz Eilingsfeld
  • Process for the preparation of bis(4-hydroxyphenyl) sulfone
    Patent number: 5072049
    Abstract: A process for the preparation of bis(4-hydroxyphenyl) sulfone by reacting phenol with sulfuric acid at a temperature of from 140.degree. to 230.degree. C., wherein the sulfuric acid is metered in to the phenol only after the reaction temperature has been reached, the phenol and sulfuric acid are used in a molar ratio of from 1:1 to 25:1 and the reaction is carried out in the absence of an inert solvent.
    Type: Grant
    Filed: January 3, 1990
    Date of Patent: December 10, 1991
    Assignee: BASF Aktiengesellschaft
    Inventors: Michael Stumpp, Peter Neumann, Bernd Hupfeld, Helmut Reichelt
  • Preparation of bis(4-hydroxyphenyl)sulfone
    Patent number: 5059715
    Abstract: A process for the preparation of bis(4-hydroxyphenyl)sulfone by reacting phenol with sulfuric acid in the presence of a solvent at from 130.degree. to 220.degree. C. and in the presence or absence of a sulfonating assistant, wherein the bis(4-hydroxyphenyl)sulfone formed is selectively deposited on a nucleating surface during or after the reaction, and thus removed from the reaction medium.
    Type: Grant
    Filed: March 14, 1991
    Date of Patent: October 22, 1991
    Assignee: BASF Aktiengesellschaft
    Inventors: Michael Stumpp, Peter Neumann, Wolfgang Ruehenback, Michael Bergner
  • Preparation of bis-(4-chlorophenyl) sulfone
    Patent number: 4983773
    Abstract: Bis-(4-chlorophenyl) sulfone is prepared by reacting chlorobenzene with sulfuric acid at from 200.degree. to 250.degree. C. by a process in which a condensing agent is added.
    Type: Grant
    Filed: October 5, 1989
    Date of Patent: January 8, 1991
    Assignee: BASF Aktiengesellschaft
    Inventors: Michael Stumpp, Peter Neumann, Heinz Eilingsfeld
  • Isolation of 4,4'-dichlorodiphenyl sulfone
    Patent number: 4873372
    Abstract: A process for the isolation of 4,4'-dichlorodiphenyl sulfone from a mixture of dichlorodiphenyl sulfones in which the ratios of the masses of 2,4'-dichlorodiphenyl sulfone and 3,4'-dichlorodiphenyl sulfone to the mass of 4,4'-dichlorodiphenyl sulfone are respectively from 0.5% to 20% and from 0.5% to 30% by treating the mixture with an alkanol at temperatures of from 20.degree. C. to 250.degree. C., cooling, and separating the pure 4,4'-dichlorodiphenyl sulfone that precipitates.
    Type: Grant
    Filed: January 25, 1988
    Date of Patent: October 10, 1989
    Assignee: BASF Aktiengesellschaft
    Inventors: Gerhard Schaefer, Heinz Eilingsfeld, Peter Neumann, Michael Stumpp