Patents by Inventor Peter J. Hartmann

Peter J. Hartmann 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).

  • Zinc-free preparation of rayon fibers
    Patent number: 4405549
    Abstract: Rayon fibers having high wet modulus, low wet elongation and low caustic solubility are prepared from an unmodified viscose spinning solution by spinning the viscose solution into a zinc-free coagulation bath containing at least 125 g/l of Na.sub.2 SO.sub.4, at least 125 g/l of (NH.sub.4).sub.2 SO.sub.4 and less than 100 g/l of H.sub.2 SO.sub.4 while the bath is at a temperature above 40.degree. C. The coagulated filament is then stretched in a secondary bath maintained at a temperature over 70.degree. C.
    Type: Grant
    Filed: July 13, 1981
    Date of Patent: September 20, 1983
    Assignee: International Telephone and Telegraph Corporation
    Inventors: Albin F. Turbak, Peter J. Hartmann
  • Zinc-free preparation of rayon fibers
    Patent number: 4402899
    Abstract: Rayon fibers having a C-shaped cross section and characterized by low caustic solubility are prepared from an unmodified viscose spinning solution having a salt index below 14 by spinning the viscose solution into a zinc-free coagulation bath containing at least 100 g/l of Na.sub.2 SO.sub.4, at least 175 g/l of (NH.sub.4).sub.2 SO.sub.4 and more than 100 g/l of H.sub.2 SO.sub.4 while the bath is at a temperature above 40.degree. C. The coagulated filament is then stretched in a secondary bath maintained at a temperature over 70.degree. C.
    Type: Grant
    Filed: July 13, 1981
    Date of Patent: September 6, 1983
    Assignee: International Telephone and Telegraph Corporation
    Inventors: Peter J. Hartmann, Albin F. Turbak
  • Flame resistant cellulosic product containing antimony pentoxide and polyvinyl bromide
    Patent number: 4123398
    Abstract: A regenerated cellulosic product is made flame resistant by the addition to the cellulosic solution from which the product is regenerated of from 3 to 7% by weight of colloidal antimony pentoxide and from 5 to 30% by weight of polyvinyl bromide.
    Type: Grant
    Filed: May 25, 1977
    Date of Patent: October 31, 1978
    Assignee: International Telephone and Telegraph Corporation
    Inventors: David G. Unrau, Norman A. Portnoy, Peter J. Hartmann