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US 2010/0305270 A1Published application
Vinyl alcohol copolymers for use in aqueous dispersions and melt extruded articles
AssigneeSekisui Specialty Chemicals America, LLC
InventorRichard Vicari
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Abstract
A product comprising a cold water soluble film wherein: a) the film comprises a copolymer of vinyl alcohol (VOH) with a minor amount of 2-acrylamido-2-methyl propane sulfonic acid in free acid form or as a salt of the free acid (AMPS); and b) the film has a harsh chemical dissolution time of less than about 80 seconds measured by the harsh chemical dissolution test method after 8 weeks.
Claims14
A process for the production of a copolymer of vinyl alcohol (VOH) and a comonomer comprising:
- a) continuously feeding with agitation, vinyl acetate (VAM) and comonomer, a free radical yielding polymerization initiator, and a solvent to a first reaction zone under polymerization conditions for a residence time sufficient for a major proportion of comonomer fed to said first reaction zone to polymerize;
- b) continuously feeding reaction mass from said first reaction zone with an additional supply of comonomer to a second reaction zone, maintaining the reaction mass in the second reaction zone for a residence time sufficient to polymerize a major proportion of the comonomer added to the second reaction zone;
- c) continuously withdrawing reaction mass from the second reaction zone;
- d) separating copolymer from the reaction mass of step (c);
- and
- e) saponifying by hydrolysis and/or alcoholysis a major proportion of the acetate groups in said copolymer to form a copolymer of VOH.
3 more elements
Dependencies are inferred from the claim text.