Patents by Inventor Donald F. Stewart

Donald F. Stewart 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: 5168108
    Abstract: Nylon compositions useful for molding and film applications with film properties and impact strength are made of a polyamide resin and a block copolymer of poly(amide-ether) of the formula ##STR1## where R is an alkyl or substituted alkyl group with from one to 12 carbons, n is an integer from 2 to 20, m is an integer from 2 to 6, and x and y are numbers from about 50 to about 30,000. In one embodiment, a nonpolymeric amide is added to the composition. Articles made from the claimed compositions have improved impact strength; films made from the compositions have improved drapeability over the unmodified resin, both at room temperature and after heat-aging. Reinforced compositions are obtained by including mineral and other reinforcing fillers, including glass fibers, in the extrusion process. The reinforced compositions exhibit improved impact characteristics.
    Type: Grant
    Filed: August 27, 1990
    Date of Patent: December 1, 1992
    Assignee: Allied Signal Inc.
    Inventors: Varkki P. Chacko, George M. Johns, Mocherla K. Rao, Michael F. Tubridy, Donald F. Stewart
  • Patent number: 5153275
    Abstract: Nylon compositions useful for molding and film applications with film properties and impact strength are made of a polyamide resin and a block copolymer of poly(amide-ether) of the formula ##STR1## where R is an alkyl or substituted alkyl group with from one to 12 carbons, n is an integer from 2 to 20, m is an integer from 1 to 6, and x and y are numbers from about 50 to about 30,000. In one embodiment, a non-polymeric amide is added to the composition. Articles made from the claimed compositions have improved impact strength; films made from the compositions have improved drapeability over the unmodified resin, both at room temperature and after heat-aging. Reinforced compositions are obtained by including mineral and other reinforcing fillers, including glass fibers, in the extrusion process. The reinforced compositions exhibit improved impact characteristics.
    Type: Grant
    Filed: August 27, 1990
    Date of Patent: October 6, 1992
    Assignee: Allied-Signal Inc.
    Inventors: Varkki P. Chacko, George M. Johns, Mocherla K. Rao, Michael F. Tubridy, Donald F. Stewart
  • Patent number: 4970274
    Abstract: Nylon compositions useful for molding and film applications with film properties and impact strength are made of a polyamide resin and a block copolymer of poly(amide-ether) of the formula ##STR1## where R is an alkyl or substituted alkyl group with from one to 12 carbons, n is an integer from 2 to 20, m is an integer from 2 to 6, and x and y are numbers from about 50 to about 30,000. In one embodiment, a non-polymeric amide is added to the composition. Articles made from the claimed compositions have improved impact strength; films made from the compositions have improved drapeability over the unmodified resin, both at room temperature and after heat-aging. Reinforced compositions are obtained by including mineral and other reinforcing fillers, including glass fibers, in the extrusion process. The reinforced compositions exhibit improved impact characteristics.
    Type: Grant
    Filed: May 1, 1989
    Date of Patent: November 13, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Varkki P. Chacko, George M. Johns, Mocherla K. Rao, Michael F. Tubridy, Donald F. Stewart
  • Patent number: 4581274
    Abstract: Carpet underlaying comprising perforated nylon film bonded to pad, provided for slippage between the carpet and the pad during installation, and minimal noise when the carpet is walked on.
    Type: Grant
    Filed: August 6, 1984
    Date of Patent: April 8, 1986
    Assignee: Allied Corporation
    Inventors: G. Michael Johns, Donald F. Stewart, Harold W. Tuller
  • Patent number: 4556696
    Abstract: The present invention is a process to form a composition comprising from 5 to 50% by weight and preferably from 10 to 30% by weight polycaprolactam and from 50 to 95% by weight and preferably 70 to 90% by weight poly(hexamethylene adipamide). The process comprises heating the composition to from 440.degree. to 505.degree. F. and preferably 450.degree. to 485.degree. F. The preferred forming process is to form the composition into a film.
    Type: Grant
    Filed: April 26, 1984
    Date of Patent: December 3, 1985
    Assignee: Allied Corporation
    Inventors: Donald F. Stewart, Michael F. Tubridy, Herbert J. Huthwaite