Patents by Inventor Dieter Constant

Dieter Constant 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: 5668204
    Abstract: A thermoplastic molding composition containing an aromatic polycarbonate and a particular siloxane compound is disclosed. The composition which is based on a polycarbonate resin having bifunctional structural units corresponding to formula (Ia) ##STR1## wherein R.sup.1 and R.sup.2 denote, independently of one another, hydrogen, halogen, C.sub.1 -C.sub.8 alkyl, C.sub.5 -C.sub.6 -cycloalkyl, C.sub.6 -C.sub.10 -aryl, or C.sub.7 -C.sub.12 -aralkyl,m is an integer from 4 to 7,R.sup.3 and R.sup.4 selected individually for each X, denote, independently of one another, hydrogen or C.sub.1 -C.sub.6 -alkyl, andX stands for carbon,under the condition that R.sup.3 and R.sup.4 are both alkyl groups on at least one X atom, andcontains from 0.001 to 1% by weight of at least one siloxane corresponding to formula (II) ##STR2## wherein R denotes hydrogen, C.sub.1 -C.sub.20 -alkyl, C.sub.6 -C.sub.10 -aryl or C.sub.1 -C.sub.
    Type: Grant
    Filed: March 19, 1992
    Date of Patent: September 16, 1997
    Assignee: Bayer Aktiengesellschaft
    Inventors: Helmut-Martin Meier, Uwe Westeppe, Rolf Dhein, Dieter Freitag, Dieter Constant
  • Patent number: 5456861
    Abstract: Process for pretreating abietic acid derivatives comprising dissolving an abietic derivative in water to form a 2 to 25% by weight solution, adding a base so that the pH of the solution is from 10 to 14 and removing from 0.5 to 25% by weight of the abietic acid derivative originally present in the solution by extraction or steam distillation while maintaining the pH from 10 to 14.
    Type: Grant
    Filed: April 18, 1990
    Date of Patent: October 10, 1995
    Assignee: Bayer AG
    Inventors: Karl-Erwin Piejko, Dieter Constant, Christian Lindner, Claus Wulff
  • Patent number: 5250622
    Abstract: A process for the preparation of polymer combinations having high rubber contents from A) aromatic polyesters and B) at least partially cross-linked rubbers, in which1) an aqueous rubber latex having a rubber solids content of up to 65% by weight is mixed with an aqueous alkali metal diphenolate solution and a water immiscible organic solvent in a quantity of from 10 to 1000 parts by weight per 100 parts by weight of rubber in the latex,2) the mixture obtained according to 1) is reacted with dicarboxylic acid halides and/or carbonyl halides and3) the polymer combination is recovered.
    Type: Grant
    Filed: March 23, 1992
    Date of Patent: October 5, 1993
    Assignee: Bayer Aktiengesellschaft
    Inventors: Holger Lutjens, Karl-Erwin Piejko, Christian Lindner, Dieter Constant