Abstract: Process for producing polyvinyl ester having a high degree of polymerization and an intrinsic viscosity of from 15 dl g.sup.-1 to 3.2 dl g.sup.-1, and a polyvinyl ester obtained thereby. The process comprises subjecting a vinyl ester monomer to emulsion polymerization using nonionic emulsifiers nonionic-anionic emulsifiers, or anionic emulsifiers and a redox initiator at a temperature of -60.degree. to 15.degree. C.

Abstract: Provided are compositions comprising a saponified product of an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 80 mol % and a saponification degree of vinyl acetate component of at least 95 mol %, said composition containing 20 to 200 ppm as converted to alkali metal of an alkali metal acetate, 30 to 250 ppm of acetic acid, and 5 to 500 ppm as converted to phosphate ion of phosphoric acid or an alkali metal hydrogenphosphate, and having a content ratio of acetic acid/alkali metal acetate of 0.1 to 1 and the flow characteristic that the extrusion rate does not substantially increase for at least 10 hours in the relationship between the heating time and the extrusion rate with a capillary rheometer (Koka Flow Tester) at at least one temperature 10.degree. to 80.degree. C. above the melting point.

Abstract: Disclosed herein is a new process for producing polyvinyl ester having a high degree of polymerization having an intrinsic viscosity not less than 1.5 dl/g, preferably not less than 2.2 dl/g, and most preferably higher than 3.2 dl/g, said process comprising subjecting vinyl ester monomer to low-temperature emulsion polymerization under specific conditions.Disclosed also herein is a new process for producing polyvinyl alcohol having a high degree of polymerization having an intrinsic viscosity not less than 1.5 dl/g, preferably not less than 2.2 dl/g, and most preferably higher than 3.2 dl/g, said process comprising saponifying in the usual way the polyvinyl ester obtained by low-temperature emulsion polymerization under specific conditions.

Abstract: An aqueous dispersion comprising a dispersoid of an ethylene-vinyl alcohol copolymer having an ethylene content of 15 to 65 mole % and a dispersion stabilizer of a saponified product of an ethylene-vinyl ester copolymer having an ionic group and having an ethylene content of 10 to 70 mole % and a saponification degree of at least 80%. According to the present invention, aqueous dispersions with high solid concentration and having excellent stability during storage or upon use. The film obtained by applying and then drying the aqueous dispersion has excellent gas barrier properties.

Abstract: An aqueous dispersion comprising a dispersoid of an ethylene-vinyl alcohol copolymer having an ethylene content of 15 to 65 mole % and a dispersion stabilizer of a saponified product of an ethylene-vinyl ester copolymer having an ionic group and having an ethylene content of 10 to 70 mole % and a saponification degree of at least 80%. According to the present invention, aqueous dispersions with high solid concentration and having excellent stability during storage or upon use. The film obtained by applying and then drying the aqueous dispersion has excellent gas barrier properties.

Abstract: Provided are compositions comprising a saponified product of an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 80 mol % and a saponification degree of vinyl acetate component of at least 95 mol %, said composition containing 20 to 200 ppm as converted to alkali metal of an alkali metal acetate, 30 to 250 ppm of acetic acid, and 5 to 500 ppm as converted to phosphate ion of phosphoric acid or an alkali metal hydrogenphosphate, and having a content ratio of acetic acid/alkali metal acetate of 0.1 to 1 and the flow characteristic that the extrusion rate does not substantially increase for at least 10 hours in the relationship between the heating time and the extrusion rate with a capillary rheometer (Koka Flow Tester) at at least one temperature 10.degree. to 80.degree. C. above the melting point.

Abstract: The present invention relates to a method of aqueous printing on a recording medium for ink, the recording medium having an excellent ink absorbing property and a markedly excellent waterproof property, the method characterized in that the recording medium comprises a substrate containing a composition which comprises polyvinyl alcohol, chitosan and an aldehyde compound.

Abstract: This invention provides a water-soluble binder and a hot-melt binder for ceramics molding, said binder being composed of a polyvinyl alcohol-based copolymer containing (meth)allyl group-containing nonionic monomer units or nitrogeneous group-containing nonionic monomer units.

Abstract: Disclosed herein is a highly compatible polymer composition which comprises (A) starch, (B) vinyl alcohol polymer having an alkyl group of 4 to 50 carbon atoms at the terminal, and/or (C) polyvinyl alcohol. Disclosed also herein is a textile sizing agent having outstanding weavability which comprises (A) starch, (B) vinyl alcohol polymer having an alkyl group of 4 to 50 carbo atoms at the terminal, (C) polyvinyl alcohol, and (D) oil for textile sizing.

Abstract: The present invention provides a process for producing easily on an industrial scale a polyvinyl ester having a high degree of polymerization and PVA having a high degree of polymerization derived by saponification form such a polyvinyl ester. The process of this invention makes it possible to produce the desired product especially even when the polymerization is carried out until a high conversion to polymer is attained, as well as even when the polymerization is suspended while the conversion to polymer is still low.

Abstract: Disclosed herein is a new process for producing polyvinyl ester having a high degree of polymerization having an intrinsic viscosity not less than 1.5 dl/g, preferably not less than 2.2 dl/g, and most preferably higher than 3.2 dl/g, said process comprising subjecting vinyl ester monomer to low-temperature emulsion polymerization under specific conditions.Disclosed also herein is a new process for producing polyvinyl alcohol having a high degree of polymerization having an intrinsic viscosity not less than 1.5 dl/g, preferably not less than 2.2 dl/g, and most preferably higher than 3.2 dl/g, said process comprising saponifying in the usual way the polyvinyl ester obtained by low-temperature emulsion polymerization under specific conditions.

Abstract: This invention relates to a water resistant composition which comprises (A) polyvinyl alcohol, (B) a chitosan of which aqueous 1% solution has a viscosity not greater than 70 centipoise at 20.degree. C. and (C) an aldehyde compound, as well as a heat-sensitive recording sheet which comprises said composition. The composition has excellent water resistant properties and the heat-sensitive recording sheet has improved color forming properties and excellent resistance to water and solvents.

Abstract: The present invention relates to a polymer having a thiol group at one end of the molecule, which is obtained by subjecting the monomers capable of radical polymerization to radical polymerization in the presence of a thiolcarboxylic acid and then treating the resulting polymer with an alkali or acid; to a process for producing the same; and to a block copolymer based on the polymer having a thiol group at the end.The polymer having a thiol group at one end is difficult of forming disulfide linkages by oxidation and thus difficult of becoming insoluble. It is also a highly reactive material that will find wide use in varied application areas. The block copolymer based on the polymer having a thiol group at the end is superior in compatibility and will find wide use in varied application areas.

Abstract: A photosensitive composition which comprises:(a) a vinyl alcohol polymer having at least one thiol group in the molecule thereof,(b) an ethylenically unsaturated compound which is radically polymerizable, and,(c) a photoinitiator,and is free from the defect of the removal of the vinyl alcohol polymer at the hardened regions upon development with water.

Abstract: A polymer composition of excellent compatibility which comprises a block copolymer containing a polyvinyl alcohol polymer unit as one constituent and a polymer unit having an ionic group as another constituent, and protein. It is suitable, especially when the protein is gelatin, for making a photographic emulsion, microcapsules, or a photosensitive material, among others.

Abstract: A polymer having a fluorine-containing end group which is produced by polymerizing a monomer capable of radical polymerization in the presence of a fluorine-containing thiol; a vinyl ester polymer having a fluorine-containing end group which is produced by polymerizing vinyl ester in the presence of a fluorine-containing thiol; and vinyl alcohol polymer having a fluorine-containing end group which is produced by saponifying the said vinyl ester polymer; and processes for producing the same are provided.The polymers of this invention are superior in water repellency, oil repellency, heat resistance, chemical resistance, and surface activity which are characteristic of fluorocarbon compounds, and are expected to find use in various application areas.

Abstract: The present invention relates to a polymer having a thiol group at one end of the molecule, which is obtained by subjecting the monomers capable of radical polymerization to radical polymerization in the presence of a thiolcarboxylic acid and then treating the resulting polymer with an alkali or acid; to a process for producing the same; and to a block copolymer based on the polymer having a thiol group at the end.The polymer having a thiol group at one end is difficult of forming disulfide linkages by oxidation and thus difficult of becoming insoluble. It is also a highly reactive material that will find wide use in varied application areas such as capture of heavy metals by forming a mercaptide. The block copolymer based on the polymer having a thiol group at the end is superior in compatibility and will find wide use in varied application areas such as surface size for paper, textile fiber finishing, additives for adhesives and paints, and binders for non woven textiles.

Abstract: A water-soluble cationic copolymer and methods for producing the same is disclosed which comprises comonomer units respectively represented by the formulae: ##STR1## wherein R.sup.1 is H or lower alkyl; B is ##STR2## R.sup.2, R.sup.3 and R.sup.4 are each independently lower alkyl or lower alkyl which contain a substituent; X is an anion capable of forming a salt with the ammonium nitrogen; and A is a group which links the nitrogen atom in B to the amide nitrogen atom.These copolymers are used in preparing paper strength additives.

Abstract: Cationic emulsions are obtained by the emulsion polymerization or copolymerization of ethylenically unsaturated monomers such as vinyl acetate, etc. in the presence of a cationic group-modified polyvinyl alcohol (PVA). Typical cationic group-modified PVA are the modified PVA's which contain a copolymeric unit having one of the following formulas: ##STR1## wherein R.sup.1 is H or lower alkyl; B is ##STR2## R.sup.2, R.sup.3 and R.sup.4 are each lower alkyl (substituted or unsubstituted) and X is an anion forming a salt with the ammonium N; and A is an inert bivalent organic group linking the N atom in B to the N atom in the amide group; ##STR3## wherein, in formulas (II) and (III), R.sup.5, R.sup.6 and R.sup.7 are each H, lower alkyl or phenyl; R.sup.8 is lower alkyl; and Y is an anion forming a salt with the imidazolinium N atom. Particularly desirable are the cationic group-modified PVA's containing the copolymeric unit (I) wherein A is ##STR4## R.sup.2, R.sup.3 and R.sup.

Abstract: A pressure-sensitive adhesive composition based on liquid rubber, a cross-linking agent therefor and a tackifier, in which the liquid rubber component is a modified low molecular weight polyisoprene which is obtainable by adding 0.03 to 7 mol % of maleic anhydride or a derivative thereof, based on each isoprene monomer unit, to a low molecular weight polyisoprene having a molecular weight in the range of 10,000 to 90,000 is useful in producing a pressure-sensitive adhesive composition having very desirable tackiness, cohesive force and bonding characteristics without use of an organic solvent or with use of only a small amount of the solvent.