Abstract: The present invention relates to ethylene-vinyl alcohol copolymer particles, comprising an ethylene-vinyl alcohol copolymer having an ethylene unit content of 1 mol % or more and less than 20 mol %, a viscosity-average polymerization degree of 200 to 5000, and a saponification degree of 80 to 99.99 mol %, wherein a crystallinity in water Cw (30° C.) at 30° C. and a crystallinity in water Cw (70° C.) at 70° C. as determined by pulse NMR satisfy formula (I). There is thus provided ethylene-vinyl alcohol copolymer particles having excellent solubility in water and excellent gas barrier performance.

Abstract: A water-based adhesive for a paper straw, comprising: an ethylene-vinyl alcohol copolymer (A); and water, wherein the ethylene-vinyl alcohol copolymer (A) has a content of ethylene units of 1 mol % or more and less than 20 mol % and a block character of the ethylene units from 0.90 to 0.99. The water-based adhesive contains the ethylene-vinyl alcohol copolymer (A) having a specific structure, and is thus excellent in balance between the rapid coatability, the film strength, the initial adhesiveness, the dynamic water resistance, and the acid resistance, and particularly excellent in the rapid coatability, the film strength, and the acid resistance.

Abstract: The present invention provides a modified vinyl alcohol polymer having a side chain with an ethylenic double bond, and having reduced a water-insoluble content and superior storage stability in the form of an aqueous solution, methods of making thereof, a modified vinyl alcohol polymer (A) having a degree of saponification of 68 mol % or more and less than 99.9 mol %, and a viscosity-average degree of polymerization of 200 or more and less than 3,000, and comprising a side chain with 0.01 mol % or more and less than 0.50 mol % of a double bond derived from an esterification agent, the esterification agent being one or more selected from the group consisting of (i) itaconic acid and/or derivatives thereof, and (ii) methacrylic acid and/or derivatives thereof, and the modified vinyl alcohol polymer (A) having a peak width W0.05h of at least 2.85 minutes and less than 3.70 minutes at a height of 5% from the baseline in a peak measured by HPLC.

Abstract: The present invention provides a modified vinyl alcohol polymer having a side chain with an ethylenic double bond, and having reduced a water-insoluble content and superior storage stability in the form of an aqueous solution. The present invention also provides a method for producing such a modified vinyl alcohol polymer. A dispersion stabilizer for suspension polymerization comprising the modified vinyl alcohol polymer is also provided that provides superior polymerization stability during suspension polymerization of a vinyl compound, and with which reduced formation of coarse particles, high bulk specific gravity, and superior plasticizer absorbability can be achieved, in addition to reducing fisheyes. The present invention also provides a method for producing a vinyl polymer. The present invention relates to a modified vinyl alcohol polymer (A) having a degree of saponification of 68 mol % or more and less than 99.

Abstract: The present invention relates to ethylene-vinyl alcohol copolymer particles, comprising an ethylene-vinyl alcohol copolymer having an ethylene unit content of 1 mol % or more and less than 20 mol %, a viscosity-average polymerization degree of 200 to 5000, and a saponification degree of 80 to 99.99 mol %, wherein a crystallinity in water Cw (30° C.) at 30° C. and a crystallinity in water Cw (70° C.) at 70° C. as determined by pulse NMR satisfy formula (I). There is thus provided ethylene-vinyl alcohol copolymer particles having excellent solubility in water and excellent gas barrier performance.

Abstract: The present invention relates to an aqueous emulsion including an ethylenically unsaturated monomer unit-containing polymer as a dispersoid and a polyvinyl alcohol as a dispersant. The content of a free polyvinyl alcohol in the aqueous emulsion is 0.2 to 20 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer unit-containing polymer. The free polyvinyl alcohol has a degree of saponification of 80.0 to 99.5 mol % and a viscosity-average degree of polymerization of 200 to 5000, and the free polyvinyl alcohol has a symmetry factor (W0.05h/2f) that satisfies the following expression (1) as determined by gradient high-performance liquid chromatography for reversed-phase separation using a water-acetone eluent according to JIS K 0124 (2011). 0.85?W0.05h/2f?1.30??(1) (The definitions of the symbols are omitted.

Abstract: The present invention relates to an aqueous emulsion including an ethylenically unsaturated monomer unit-containing polymer as a dispersoid and a polyvinyl alcohol as a dispersant. The content of a free polyvinyl alcohol in the aqueous emulsion is 0.2 to 20 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer unit-containing polymer. The free polyvinyl alcohol has a degree of saponification of 80.0 to 99.5 mol % and a viscosity-average degree of polymerization of 200 to 5000, and the free polyvinyl alcohol has a symmetry factor (W0.05h/2f) that satisfies the following expression (1) as determined by gradient high-performance liquid chromatography for reversed-phase separation using a water-acetone eluent according to JIS K 0124 (2011). 0.85?W0.05h/2f?1.30??(1) (The definitions of the symbols are omitted.

Abstract: Provided is a vinyl alcohol polymer that provides a coating film having superior water resistance and binder performances, and has sufficient solubility in water and viscosity stability even in a neutral pH region. Further provided are an aqueous solution, a coating agent, an ink jet recording material, a thermal recording material and a base paper for a release paper that comprise the vinyl alcohol polymer, and a method for producing same, and the like. The vinyl alcohol polymer includes a monomer unit represented by the following formula (1), with the following inequality (I) being satisfied. Preferably, the following inequalities (II) and (III) are further satisfied according to the PVA: wherein, P represents the viscosity average degree of polymerization; and S represents the content (mol %) of the monomer unit.

Abstract: An alkyl-modified PVA solution is provided which has low viscosity at high temperatures leading to superior handleability, accompanied by rapidly increased viscosity upon lowering of the temperature, even in the case in which the concentration of the alkyl-modified PVA in a solution is increased. An alkyl-modified vinyl alcohol polymer solution containing an alkyl-modified vinyl alcohol polymer, a surfactant and water. The alkyl-modified vinyl alcohol polymer has a monomer unit that includes an alkyl group having 5 to 29 carbon atoms. The percentage content of the monomer unit is no less than 0.05 mol % and no greater than 5 mol %. The degree of saponification of the alkyl-modified vinyl alcohol polymer is no less than 20 mol % and no greater than 99.99 mol %. The surfactant is a compound represented by the following formula (I) having hydrophilic groups X1 and X2, and an alkyleneoxy group having 3 to 5 carbon atoms (—R1—O—).

Abstract: Provided is a composition comprising: a vinyl alcohol polymer (A) comprising a monomer unit having a group represented by a formula (1); and a compound (B) comprising a silicon atom, a titanium atom, a zirconium atom or a combination thereof, at a content of 0.01 parts by mass or greater and 900 parts by mass or less with respect to 100 parts by mass of the vinyl alcohol polymer (A), wherein an inequality (I) is satisfied: 370?P×S?6,000??(I) wherein, P represents a viscosity average degree of polymerization; and S represents a percentage content (mol %) of the monomer unit. Also provided are a coating agent containing the composition, and a coated article, a thermal recording material, an ink jet recording material and a base paper for a release paper that are produced using the coating agent, and a method for producing a coated article.

Abstract: A polyvinyl alcohol polymer capable of, in producing hydrolyzable cellulose using a cellulosic biomass as a basic material, readily disrupting the cellulosic biomass at a molecular level by imparting a suitable flow resistance to a solution containing the cellulosic biomass, or the like, thereby resulting in efficient production of hydrolyzable cellulose to be enabled; and a method for producing hydrolyzable cellulose using the polyvinyl alcohol polymer. Provided is a polyvinyl alcohol polymer for use in producing hydrolyzable cellulose using a cellulosic biomass as a basic material, the polyvinyl alcohol polymer having: an average degree of polymerization of no less than 200 and no greater than 5,000; a degree of saponification of no less than 70 mol % and no greater than 99.9 mol %; and a molecular weight distribution of no less than 2.2.

Abstract: Provided is a polyoxyalkylene modified vinyl alcohol-based polymer comprising a polyoxyalkylene group in a side chain, wherein the polymer has a viscosity average degree of polymerization of not less than 150 and not more than 5000, a degree of saponification of not less than 40 mol % and not more than 99.99 mol %, and a polyoxyalkylene group modification rate of not less than 0.05 mol % and not more than 10 mol %; and the polyoxyalkylene group is composed of a polyoxypropylene block and a (poly)oxyethylene block and is represented by the following general formula (I). Such polymer is excellent in temperature-sensitive thickening properties. (in the general formula (I), R1 denotes a hydrogen atom or an alkyl group having a carbon number of from 1 to 8; either one of R2 and R3 is a methyl group and the other is a hydrogen atom; and 10?m?40 and 1?n?50).

Abstract: The present invention provides a halogen-containing resin composition comprising 100 parts by weight of a halogen-containing resin; 0.01 to 2.5 parts by weight of a polyvinyl alcohol having a saponification degree of from 60 to 99.9 mol % and a viscosity-average polymerization degree of from 100 to 1,000; 0.01 to 2.5 parts by weight of a polyol having a molecular weight of 2,000 or less and a hydroxyl content of 10% by weight or more; and 0.01 to 5 parts by weight of a zinc compound.

Abstract: An object of the invention is to provide a novel alkyl-modified PVA capable of exerting superior thickening properties while maintaining high water solubility, and also capable of having high water resistance in a state being hardened without using an especial crosslinking agent. In addition, another object is to provide a composition, a thickener, a coating material for papers, a coated paper, an adhesive and a film containing the alkyl-modified PVA. Provided is an alkyl-modified vinyl alcohol polymer containing (a) a monomer unit represented by the following general formula (I): wherein, R1 represents a linear or branched alkyl group having 8 to 29 carbon atoms; and R2 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and has a viscosity average degree of polymerization of no less than 200 and no greater than 5,000, a degree of saponification of no less than 20 mol % and no greater than 99.99 mol %, and a content of the monomer unit (a) of no less than 0.

Abstract: The present invention provides a dispersion stabilizer having an excellent polymerization stability. When used for suspension polymerization of vinyl compounds even in small amounts, the dispersion stabilizer according to the present invention attains the effects that: with respect to vinyl polymer particles to be obtained, the plasticizer absorptivity is high, leading to easy processing; residual monomer components such as a vinyl compound can be removed easily; the number of coarse particles is small; the obtained particles are as uniform as possible in particle size so that formation of fish-eyes can be prevented. The present invention provides a dispersion stabilizer for suspension polymerization including a polyvinyl alcohol polymer (A) having a saponification degree of 60 mol % or more and a polymerization degree of 200 or more, and a polyvinyl alcohol polymer (C) obtained by esterifying a polyvinyl alcohol polymer (B) having a saponification degree of less than 60 mol % with a carboxylic acid compound.

Abstract: An alkyl-modified PVA solution is provided which has low viscosity at high temperatures leading to superior handleability, accompanied by rapidly increased viscosity upon lowering of the temperature, even in the case in which the concentration of the alkyl-modified PVA in a solution is increased. An alkyl-modified vinyl alcohol polymer solution containing an alkyl-modified vinyl alcohol polymer, a surfactant and water. The alkyl-modified vinyl alcohol polymer has a monomer unit that includes an alkyl group having 5 to 29 carbon atoms. The percentage content of the monomer unit is no less than 0.05 mol % and no greater than 5 mol %. The degree of saponification of the alkyl-modified vinyl alcohol polymer is no less than 20 mol % and no greater than 99.99 mol %. The surfactant is a compound represented by the following formula (I) having hydrophilic groups X1 and X2, and an alkyleneoxy group having 3 to 5 carbon atoms (—R1—O—).

Abstract: Provided is a composition comprising: a vinyl alcohol polymer (A) comprising a monomer unit having a group represented by a formula (1); and a compound (B) comprising a silicon atom, a titanium atom, a zirconium atom or a combination thereof, at a content of 0.01 parts by mass or greater and 900 parts by mass or less with respect to 100 parts by mass of the vinyl alcohol polymer (A), wherein an inequality (I) is satisfied: 370?P×S?6,000??(I) wherein, P represents a viscosity average degree of polymerization; and S represents a percentage content (mol %) of the monomer unit. Also provided are a coating agent containing the composition, and a coated article, a thermal recording material, an ink jet recording material and a base paper for a release paper that are produced using the coating agent, and a method for producing a coated article.

Abstract: Provided is a polyoxyalkylene modified vinyl alcohol-based polymer comprising a polyoxyalkylene group in a side chain, wherein the polymer has a viscosity average degree of polymerization of not less than 150 and not more than 5000, a degree of saponification of not less than 40 mol % and not more than 99.99 mol %, and a polyoxyalkylene group modification rate of not less than 0.05 mol % and not more than 10 mol %; and the polyoxyalkylene group is composed of a polyoxypropylene block and a (poly)oxyethylene block and is represented by the following general formula (I). Such polymer is excellent in temperature-sensitive thickening properties. (in the general formula (I), R1 denotes a hydrogen atom or an alkyl group having a carbon number of from 1 to 8; either one of R2 and R3 is a methyl group and the other is a hydrogen atom; and 10?m?40 and 1?n?50).

Abstract: Provided is a vinyl alcohol polymer that provides a coating film having superior water resistance and binder performances, and has sufficient solubility in water and viscosity stability even in a neutral pH region. Further provided are an aqueous solution, a coating agent, an ink jet recording material, a thermal recording material and a base paper for a release paper that comprise the vinyl alcohol polymer, and a method for producing same, and the like. The vinyl alcohol polymer includes a monomer unit represented by the following formula (1), with the following inequality (I) being satisfied. Preferably, the following inequalities (II) and (III) are further satisfied according to the PVA: wherein, P represents the viscosity average degree of polymerization; and S represents the content (mol %) of the monomer unit.

Abstract: An object of the present invention is to provide a modified PVA solution that enables physical properties such as viscosity to be adjusted even when a concentration of the modified PVA having high hydrophobicity is increased, and to provide a method for producing the modified PVA solution. The modified vinyl alcohol polymer solution of the present invention comprises: a modified vinyl alcohol polymer; an organic solvent; and water, the modified vinyl alcohol polymer: comprising a monomer unit having an alkyl group having a carbon number of 2 or greater and 29 or less;, and having a percentage content of the monomer unit being no less than 0.05 mol % and no greater than 5 mol %, and a degree of saponification of the modified vinyl alcohol polymer being no less than 20 mol % and no greater than 99.99 mol %, and in terms of Hansen solubility parameters of the organic solvent, ?d being no less than 13 MPa0.5 and no greater than 18 MPa0.5, ?p being no less than 4 MPa0.5 and no greater than 9 MPa0.