Patents by Inventor Gerhard Wickenhaeuser

Gerhard Wickenhaeuser 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).

  • Recovery of aqueous glyoxylic acid solutions
    Patent number: 4902828
    Abstract: Aqueous glyoxylic acid solutions, essentially free of other acids, are recovered from aqueous solutions which still contain other acids, by a method in which the aqueous solution is mixed with an organic nitrogen compound at as high as 50.degree. C., the phases are separated, and the glyoxylic acid is extracted from the organic phase with water, at a higher temperature.
    Type: Grant
    Filed: October 18, 1984
    Date of Patent: February 20, 1990
    Assignee: BASF Aktiengesellschaft
    Inventors: Gerhard Wickenhaeuser, Bernd Heida, Fritz Graf, Leopold Hupfer
  • Purification of aqueous glyoxal solutions
    Patent number: 4521632
    Abstract: Aqueous solutions of glyoxal which contain acids are purified by treatment with a solution which contains from 20 to 60% by weight of a tertiary amine and from 80 to 40% by weight of an alcohol which is not infinitely miscible with water, the treatment being carried out by mixing the two solutions during a residence time of less than 5 minutes.
    Type: Grant
    Filed: January 23, 1984
    Date of Patent: June 4, 1985
    Assignee: BASF Aktiengesellschaft
    Inventors: Gerhard Wickenhaeuser, Bernd Heida, Fritz Graf, Leopold Hupfer
  • Conditioning of finely divided crude organic pigments
    Patent number: 4451654
    Abstract: A process for the preparation of deeply colored organic pigments by crystallizing finely divided crude organic pigments, whose primary particles have a size of .ltoreq.0.2 .mu.m, in C.sub.3 -C.sub.5 -alkanes, C.sub.3 -C.sub.5 -alkenes or C.sub.1 -C.sub.3 -chloroalkanes at from 40.degree. to 250.degree. C. to under atmospheric pressure or superatmospheric pressure, and isolating the pigment.The pigments obtained by the process give deep, brilliant colorations.
    Type: Grant
    Filed: September 20, 1982
    Date of Patent: May 29, 1984
    Assignee: BASF Aktiengesellschaft
    Inventors: Fritz Graser, Gerhard Wickenhaeuser
  • Process for drying finely divided pigments
    Patent number: 4368582
    Abstract: A process for drying finely divided pigments contained in a press cake or a suspension, wherein a mixture of the pigment and a liquid whose critical temperature is below the decomposition temperature of the pigment is heated under pressure to above the critical temperature of the liquid and is then released while keeping the temperature above the dew line of the liquid. The process gives fine pigments powders which are easily dispersible in the media in which pigments are used, and which produce deep, brilliant colorations.
    Type: Grant
    Filed: March 10, 1981
    Date of Patent: January 18, 1983
    Assignee: BASF Aktiengesellschaft
    Inventors: Fritz Graser, Gerhard Wickenhaeuser