Patents Examined by Jim Reddick
  • Two-phase process for preparing poly(vinyl alcohol)-co-poly(vinylamine)
    Patent number: 5194492
    Abstract: Vinyl acetate and an N-vinyl formamide are copolymerized to yield poly(vinyl acetate)-co-poly(N-vinyl formamide) which is base hydrolyzed to poly(vinyl alcohol)-co-poly(N-vinyl formamide). Two phase hydrolysis of particles of poly(vinyl alcohol)-co-poly(N-vinyl formamide) as a slurry in methanol yields particles of poly(vinyl alcohol)-co-poly(vinylamine).Provided is a copolymer of the following general formula ##STR1## where m is 0 to 15 mole %,n is 50 to 99 mole %, x is 0 to 30 mole %, and y is 1 to 50 mole %.
    Type: Grant
    Filed: January 2, 1992
    Date of Patent: March 16, 1993
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Robert K. Pinschmidt, Jr., Ta-Wang Lai