Abstract: An interlayer for a laminated glass is provided. The interlayer film contains (a) a polyvinyl acetal with an acetalization degree of 60 to 80 mol %, a content of a vinyl ester monomer unit of from 0.1 to 20 mol %, and a viscosity-average degree of polymerization of from 1400 to 4000, and (b) light-diffusing fine particles in which an absolute value difference between a refractive index of the light-diffusing fine particles and a refractive index of the intrlayer excluding the light-diffusing fine particles is 0.20 or more and a haze as measured in accordance with JIS K 7105 for a laminated glass prepared by sandwiching the interlayer film between two glass sheets with a thickness of 3 mm is 20% or less.

Abstract: There is provided a binder for ceramic formation or a conductive paste, comprising polyvinyl acetal having a degree of acetalization of from 50 to 85 mol %, a content of vinyl ester monomer unit of from 0.1 to 20 mol %, and having a viscosity-average degree of polymerization of from 200 to 5000, wherein a peak-top molecular weight (A) as measured by a differential refractive index detector and a peak-top molecular weight (B) as measured by an absorptiometer (measurement wavelength: 280 nm) in gel permeation chromatographic measurement of the polyvinyl acetal heated at 230° C. for 3 hours satisfy a formula (1) (A?B)/A<0.60 and the polyvinyl acetal has an absorbance in the peak-top molecular weight (B) of from 0.50×10?3 to 1.00×10?2.

Abstract: There is provided a dispersing agent for suspension polymerization of a vinyl compound comprising a polyvinyl alcohol with a saponification degree of 65 to 90 mol % which satisfies Formulas (1) to (3). It allows for reducing the amount of coarse particles during polymerization and can thus provide a vinyl polymer with a sharp particle size distribution and higher plasticizer absorbability. 0.4?(MwUV/MwRI)?0.95??(1) 3?(MwUV/MnUV)?12??(2) 0.1?A220?0.

Abstract: There is provided a multilayer film comprising a layer (X) containing a polyvinyl acetal (I) having an acetalization degree of 55 to 80 mol %, a content of a vinyl ester monomer unit of 0.1 to 1.5 mol % and a viscosity-average degree of polymerization of 1,400 to 5,000; and a layer (Y) containing a polyvinyl acetal (II) having an acetalization degree of 70 to 85 mol %, a content of a vinyl ester monomer unit of 5 to 15 mol % and a viscosity-average degree of polymerization of 1,400 to 5,000, wherein the multilayer film satisfies formulas (1) and (2): (A?B)/A<0.80 (1) and 1.00×10?2<(b/y)/(a/x)<2.00×10?1 (2). There is thus provided a film which exhibits sufficient sound-absorbability, resistance to coloration by heating, reduction in foreign materials (undissolved materials) and excellent recyclability.

Abstract: An object is to provide a polyvinyl acetal film which has excellent transparency and can suppress a thermal cracking phenomenon. The above object is achieved by providing a polyvinyl acetal film in which a ratio between a composite modulus (GPa) of the highest part in a convex part and a composite modulus (GPa) of the lowest part in a concave part on a surface of a film on a side in contact with glass, calculated by a nanoindentation measurement using a scanning probe microscope, is 0.90 or less, when a laminated glass is formed. In addition, the above object is achieved by providing a polyvinyl acetal film in which a ratio between a hardness (GPa) of the highest part in the convex part and a hardness (GPa) of the lowest part in the concave part, calculated by the SPM nanoindentation measurement, is 0.90 or less.

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: 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: Provided are a thermal stabilizer for polyvinyl chloride, comprising a mixed powder (P) containing a vinyl alcohol-based polymer (A) having an average degree of saponification from 30 to 99.9 mol % and having a viscosity average degree of polymerization of 1000 or less, and a zinc compound (B), wherein a weight ratio A/B of (A) and (B) falls within a range from 1/10 to 10/1, and the mixed powder (P) has 80 weight % or more of particles passing through a screen with 75 ?m openings, and a polyvinyl chloride resin composition, comprising: from 0.1 to 10 parts by weight of the thermal stabilizer for polyvinyl chloride based on 100 parts by weight of a polyvinyl chloride resin. Such polyvinyl chloride resin composition is excellent in the thermal stability while being molded and allows obtaining a less colored molded article.

Abstract: A polymer electrolyte membrane comprising as a main ingredient a block copolymer (P) which comprises, as its constituents, a vinyl alcoholic polymer block (A) and a polymer block (B) having ion-conducting groups, which block copolymer (P) is cross-linking treated, and a membrane-electrode assembly and a fuel cell using the polymer electrolyte membrane, respectively. Preferred as polymer block (B) is one having a styrene or vinylnaphthalene skeleton or a 2-(meth)acrylamido-2-methylpropane skeleton. The ion-conducting group includes a sulfonic acid group, a phosphonic acid group or the like.

Abstract: A polyvinyl chloride resin composition contains: from 0.005 to 5 parts by weight of a polyvinyl alcohol having structural units expressed by a formula (1); and from 0.01 to 5 parts by weight of a zinc compound, based on 100 parts by weight of a polyvinyl chloride resin. A polyvinyl chloride resin composition is thereby provided that is good in thermal stability and less colored while being shaped and also allows to obtain a shaped article thereof having less rough surface and showing little loss of transparency after melt process. (R1 and R2 independently denote a hydrogen atom, an alkyl group, or an acyl group, respectively. X denotes a single bond or an alkylene group having a carbon number of from 1 to 3 that may be mediated by an oxygen atom.

Abstract: A polymer electrolyte membrane comprising as a main ingredient a block copolymer (P) which comprises, as its constituents, a vinyl alcoholic polymer block (A) and a polymer block (B) having ion-conducting groups, which block copolymer (P) is cross-linking treated, and a membrane-electrode assembly and a fuel cell using the polymer electrolyte membrane, respectively. Preferred as polymer block (B) is one having a styrene or vinylnaphthalene skeleton or a 2-(meth)acrylamido-2-methylpropane skeleton. The ion-conducting group includes a sulfonic acid group, a phosphonic acid group or the like.

Abstract: A method for producing a polyvinyl acetal resin is provided which is characterized in that a polyvinyl alcohol and a carbonyl compound are reacted at 40 to 200° C. in a liquid containing water and/or an alcohol as solvents in the presence of an acid catalyst including carbon dioxide. By this method, a polyvinyl acetal resin having a halogen element content of ppm or less and an alkali metal element content of 1000 ppm or less can be obtained without particularly performing washing operations. Therefore, a method for producing a polyvinyl acetal resin containing only little impurities such as metal salts and acids is provided.

Abstract: The present invention provides a method for producing a polymer by conducting polymerization in a polymerization reactor having an inner wall covered with an anti-fouling agent comprising an aqueous solution containing a polyvinyl alcohol obtained through saponification of a polyvinyl ester that contains monomer units having a silyl group. In the present invention, the polyvinyl alcohol satisfies the following formulae (I) and (II): 370<P×S<9000 ??(I) where P indicates the viscosity-average degree of polymerization of the polyvinyl alcohol, and S indicates the content (mole %) of the monomer units having a silyl group of formula (1) in the polyvinyl alcohol; 0.2/100?(A?B)/(B)?75/100 ??(II) where A indicates the content (ppm) of silicon atoms in the polyvinyl alcohol, and B indicates the content (ppm) of silicon atoms in the polyvinyl alcohol that was washed with sodium hydroxide-containing methanol and then washed with methanol by Soxhlet extraction.

Abstract: The present invention provides polyvinyl alcohol based (PVA) whose solubility in water varies with a small temperature change to a sufficiently great degree. In manufacturing a polyvinyl alcohol based polymer by: progressing a transesterification reaction of a polyvinyl ester based polymer with alcohol in a liquid reaction mixture including the polyvinyl ester based polymer, the alcohol, and a basic compound; precipitating the polyvinyl ester based polymer, at least a part of which has been transesterified with the alcohol, out of the liquid reaction mixture; and further progressing the transesterification reaction in the liquid reaction mixture including the polyvinyl ester based polymer that has precipitated, the liquid reaction mixture has a temperature of 75° C. to 150° C. when the polyvinyl ester based polymer, at least a part of which has been transesterified, starts precipitating.

Abstract: The present invention provides a method for producing a polymer by conducting polymerization in a polymerization reactor having an inner wall covered with an anti-fouling agent comprising an aqueous solution containing a polyvinyl alcohol obtained through saponification of a polyvinyl ester that contains monomer units having a silyl group. In the present invention, the polyvinyl alcohol satisfies the following formulae (I) and (II): 370<P×S<9000??(I) where P indicates the viscosity-average degree of polymerization of the polyvinyl alcohol, and S indicates the content (mole %) of the monomer units having a silyl group of formula (1) in the polyvinyl alcohol; 0.2/100?(A?B)/(B)?75/100??(II) where A indicates the content (ppm) of silicon atoms in the polyvinyl alcohol, and B indicates the content (ppm) of silicon atoms in the polyvinyl alcohol that was washed with sodium hydroxide-containing methanol and then washed with methanol by Soxhlet extraction.

Abstract: The invention provides a polyvinyl acetal having a degree of acetalization of from 45 to 80 mol %, which is obtained through acetalization of a polyvinyl alcohol having a degree of polymerization of from 30 to 1000 and a degree of hydrolysis of from 80.0 to 99.99 mol % and having a specific amount of an ionic group bonded to the terminal thereof via a sulfido bond. The polyvinyl acetal of the invention is useful for binders for ceramic forming and for binders for ink or paint.

Abstract: The invention provides a polyvinyl acetal having a degree of acetalization of from 45 to 80 mol %, which is obtained through acetalization of a polyvinyl alcohol that contains from 1 to 15 mol % of ?-olefin units and has a 1,2-glycol bond content of from 1 to 3 mol %, a degree of polymerization of from 100 to 2000 and a degree of hydrolysis of from 80.0 to 99.99 mol %. The polyvinyl acetal has good waterproofness and good compatibility with plasticizer. Having the advantages, it is favorable for interlayer films for laminated glass, binders for ceramic forming, binders for ink or paint, and coating liquids for thermally-developable photographic materials.

Abstract: The invention provides a novel polyvinyl acetal having N-vinylamide monomer units in the molecule, and provides a binder with the novel polymer for ink or paint and for ceramic forming. Compared with conventional polyvinyl acetals, the novel polymer lowers the solution viscosity and increases the solid content (pigment content) of ink or paint in which the polymer serves as a binder. The binder with the novel polymer for ceramic molding enables production of thin and homogeneous ceramic green sheets of high strength.

Abstract: A polyvinyl alcohol having hydrolyzed silyl group functionalized monomer units. The polyvinyl alcohol satisfies the following formulae (I) and (II) and the pH of an aqueous 4% solution of the polyvinyl alcohol is between 4 and 8: 20<P×S<370??(I) wherein P is the viscosity-average degree of polymerization of the polyvinyl alcohol, and S is the content of the silyl group functionalized monomer units in the polyvinyl alcohol, 0.1/100?(A?B)/(B)?50/100??(II) wherein A is the silicon atom content of the polyvinyl alcohol, B is the silicon atom content of the polyvinyl alcohol that has been washed with sodium hydroxide-containing methanol and then washed through Soxhlet extraction with methanol. The polyvinyl alcohol may be readily dissolved in water in the absence of sodium hydroxide or an acid; the aqueous solution has good viscosity stability; the binding force with inorganic substances is high; and a film formed of its mixture with an inorganic substance is excellent in resistance to water.

Abstract: A polyvinyl alcohol obtained by hydrolysis of a polyvinyl ester that contains silyl group functionalized monomer units. The polyvinyl alcohol satisfies the following formula (I) and the weight fraction of the polymer molecules contained in the polyvinyl alcohol having the degree of polymerization that is more than 3 times the weight-average degree of polymerization of the whole polyvinyl alcohol molecules is at most 25% by weight: 20<Pw×S<460 ??(I) wherein Pw is the weight-average degree of polymerization of the polyvinyl alcohol, and S is the content (mol %) of the silyl group functionalized monomer units. The polyvinyl alcohol is readily dissolved in water without need for addition of an alkali or an acid; the aqueous solution have good viscosity stability; film formed of its aqueous solution have excellent water resistance; the binding force with inorganic substances is high; and a film mixture of the polyvinyl alcohol with an inorganic substance has excellent water resistance.