Patents by Inventor Barbara Brahm

Barbara Brahm 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 polyurethanes with liquid crystal properties and diisocyanates suitable for carrying out the process
    Patent number: 5008447
    Abstract: This invention relates to a process for preparing polyurethanes having liquid crystal properties comprising reacting, in proportions corresponding to an NCO/OH equivalent ratio of from about 0.9:1 to 1.1:1, an organic polyhydroxyl compound with an organic diisocyanate having at least two phenylene groups and at least one carboxylic ester group. The organic diisocyanate comprises an aliphatic diisocyanate wherein at least one of the carboxylic ester groups connects an aliphatic group to a phenylene group or an aromatic diisocyanate wherein at least one of the carboxylic acid groups connects two phenylene groups.This invention further relates to preferred diisocyanates used in the process according to this invention.
    Type: Grant
    Filed: November 7, 1989
    Date of Patent: April 16, 1991
    Assignee: Bayer Aktiengesellschaft
    Inventors: Werner Mormann, Barbara Brahm, Martin Brahm
  • Process for the preparation of polyurethanes with liquid crystal properties and diisocyanates suitable for carrying out the process
    Patent number: 4895920
    Abstract: This invention relates to a process for preparing polyurethanes having liquid crystal properties comprising reacting, in proportions corresponding to an NCO/OH equivalent ratio of from about 0.9:1 to 1.1:1, an organic polyhydroxyl compound with an organic diisocyanate having at least two phenylene groups and at least one carboxylic ester group. The organic diisocyanate comprises an aliphatic diisocyanate wherein at least one of the carboxylic ester groups connects an aliphatic group to a phenylene group or an aromatic diisocyanate wherein at least one of the carboxylic acid groups connects two phenylene groups.This invention further relates to preferred diisocyanates used in the process according to this invention.
    Type: Grant
    Filed: September 7, 1988
    Date of Patent: January 23, 1990
    Assignee: Bayer Aktiengesellschaft
    Inventors: Werner Mormann, Barbara Brahm, Martin Brahm