Abstract: This invention relates to an improved process for the production of polyvinyl alcohol containing keto-ester groups wherein a polymer containing polyvinyl alcohol units is contacted with a compound having keto-ester forming groups under conditions for forming keto-ester groups on the polymer. The improvement in the process comprises:contacting a solid polymer containing vinyl alcohol units with a liquid phase acetoacetate of the formula: ##STR1## where R is chosen independently from alkyl groups under conditions for converting the alcohol functionality to the keto ester form; and then, removing unreacted acetoacetate forming group and volatile byproduct alcohol from the solid polymer.

Abstract: A method for treating paper which comprises applying to the surface of the paper an aqueous medium containing a sizing composition consisting essentially of 75 to 99.9 wt % polyvinyl alcohol which is at least 95 mole % hydrolyzed and 0.1 to 25 wt % ketene dimer represented by the formula: ##STR1## wherein R and R.sup.1 are the same or different hydrocarbyl groups having 8-30 carbon atoms.

Abstract: A method for preparing a compatible blend of polyolefin and thermoplastic polyvinyl alcohol comprising:(a) melting polyolefin in the initial elements of a melt extruder,(b) adding and melt blending an unsaturated carboxylic acid or anhydride with the melted polyolefin downstream in the extruder,(c) adding peroxide to the melt blend and grafting the unsaturated carboxylic acid or anhydride onto the polyolefin, and(d) melt blending thermoplastic PVOH into the grafted polyolefin/unsaturated carboxylic acid or anhydride melt mixture.

Abstract: A multilayer structure, especially a multilayer film, for packaging alkaline, or caustic, compositions. The multilayer structure consists essentially of:(1) a first layer of an acid functional polymer that is soluble in aqueous alkaline medium,(2) a second layer of a partially hydrolyzed, thermoplastic PVOH, and, optionally,(3) a third layer of a fully hydrolyzed, thermoplastic PVOH.

Abstract: An extrudable polyvinyl alcohol composition useful for packaging and molding applications is prepared by melt blending polyvinyl alcohol and thermoplastic modified starch to provide a product which has reduced water sensitivity, improved modulus and reduced elongation at high relative humidity.A method for extruding the polyvinyl alcohol composition comprises:adding sufficient energy to the polyvinyl alcohol composition to both melt it and essentially eliminate the polyvinyl alcohol crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.The thermoplastic modified starch may be added to the polyvinyl alcohol before or during the melting of the polyvinyl alcohol and elimination of its crystallinity, or the starch may be blended with the thus treated polyvinyl alcohol and then melt extruding the polyvinyl alcohol/starch blend.

Abstract: A solid state process for modifying polyvinyl alcohol using a Michael-type addition wherein dry polyvinyl alcohol powder is sprayed with a solution of a monomer capable of Michael-type addition in an amount sufficient to swell the polyvinyl alcohol or maintain its swollen state, but not dissolve or form a slurry of the polyvinyl alcohol. The swollen polyvinyl alcohol is sprayed with a catalyst and the temperature is raised to initiate the reaction between the polyvinyl alcohol and the monomer.

Abstract: In a melt extrudable polyvinyl alcohol composition consisting essentially of polyvinyl alcohol and plasticizer, which has been made melt extrudable by adding sufficient energy to the polyvinyl alcohol to both melt and substantially eliminate the crystallinity in the melt while simultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol, the improvement which comprises 5 to 25 wt % poly(butylene terephthalate)-polytetrahydrofuran block copolymer for improved impact resistance.

Abstract: A modified polyvinyl alcohol and a solid state process for producing modified polyvinyl alcohol wherein polyvinyl alcohol powder is sprayed with a sufficient amount of a solution of a polymerizable monomer to swell the polyvinyl alcohol powder but not dissolve it or form a slurry. The swollen polyvinyl alcohol powder is sprayed with a free radical source (an initiator) and the temperature is raised to initiate a reaction between polyvinyl alcohol and the polymerizable monomer.

Abstract: An extrudable polyvinyl alcohol composition useful for packaging and molding applications is prepared by melt blending polyvinyl alcohol and thermoplastic polyethylene oxide to provide a product which has improved pH stability and salt solution solubility. Useful extruded articles prepared from such compositions include films and containers.A method for extruding the polyvinyl alcohol composition comprises:adding sufficient energy to the polyvinyl alcohol composition to both melt it and essentially eliminate the polyvinyl alcohol crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.The thermoplastic polyethylene oxide may be added to the polyvinyl alcohol before the polyvinyl alcohol is melted and its crystallinity eliminated or blended with the thus thermally treated polyvinyl alcohol and then melt extruding the polyvinyl alcohol/polyethylene oxide blend.

Abstract: A method for extruding polyvinyl alcohol which comprisesadding sufficient energy to the polyvinyl alcohol to both melt it and essentially eliminate the crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.Rapidly cooling the extruded melt reduces the heat history and improves the resulting color of the extrudable polyvinyl alcohol.

Abstract: A method for extruding polyvinyl alcohol which includesadding sufficient energy to the polyvinyl alcohol to both melt it and essentially eliminate the crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol andrapidly cooling the extruded melt reduces the heat history and improves the resulting color of the extrudable polyvinyl alcohol.

Abstract: An extruable polyvinyl alcohol composition useful for packaging and molding applications is prepared by melt blending polyvinyl alcohol and thermoplastic polyurethane to provide a product which has low water absorptivity, improved impact resistance, and improved low temperature/low humidity tensile properties. Useful extruded articles prepared from such compositions include films and bottles.A method for extruding the polyvinyl alcohol composition comprises:adding sufficient energy to the polyvinyl alcohol composition to both melt it and essentially eliminate the polyvinyl alcohol crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.The thermoplastic polyurethane may be added to the polyvinyl alcohol before the polyvinyl alcohol is melted and its crystallinity eliminated or blended with the thus treated polyvinyl alcohol and then melt extruding the polyvinyl alcohol/polyurethane blend.

Abstract: A vinyl acetate copolymer comprising the following general structure ##STR1## where R is hydrogen or methyl;R.sup.1 is a C.sub.6 -C.sub.18 hydrocarbyl group not containing an olefinic functionality;y is 92 to 99.5 mole %; andz is 0.5 to 8 mole %.The vinyl acetate copolymer is hydrolyzed to provide a vinyl alcohol copolymer that can be thermoplastically processed into shaped articles possessing good oxygen gas barrier properties.

Abstract: A vinyl alcohol copolymer comprising the following general structure: ##STR1## wherein R is hydrogen or methyl;X is an organic linking group such as ##STR2## R.sup.1 is C.sub.1 -C.sub.4 alkyl; R.sub.f is a perfluoronated alkyl or poly(alkyleneoxy) group;m is 0 or 1;x is 50-99.9 mole %;y is 0-50 mole %; andz is 0.001-50 mole %.The vinyl alcohol copolymer has excellent solvent barrier properties.

Abstract: An aqueous size composition for cotton-containing textile yarn comprising in an aqueous solution(a) 100 parts polyvinyl alcohol(b) 2-15 parts hydrophobic waxy material(c) 0.2-5 parts ethylene oxide-propylene oxide surfactant which has a surface tension between about 37 and 48 dynes/cm as a 0.1% aqueous solution at 25.degree. C., and a foaming number less than about 20 (ml foam/g solution).degree. F. as a 7% aqueous polyvinyl alcohol solution containing 11.4 parts hydrogenated tallow wax and 2 parts surfactant per 100 parts polyvinyl alcohol.

Abstract: A vinyl alcohol copolymer comprising the following general structure ##STR1## where R is hydrogen or methyl;R.sup.1 is a C.sub.6 -C.sub.18 hydrocarbyl group not containing an olefinic functionality;x is 70 to 99.5% mole %;y is 0 to 29.5 mole %; andz is 0.5 to 8 mole %.