Kuraray Co., Ltd.

Kurarayco., Ltd.

Tatsuya Tanida

Keisuke Morikawa

Yosuke Kumaki

Masaki Kato

Masato Nakamae

Tadahito Fukuhara

Shinsuke Nii

Yusuke Amano

Yoko Mori

Masako Katayama

Junpei Horiguchi

Keishi Hachiya

Ayumu Yamamoto

Seisuke Inada

An ethylene-vinyl alcohol copolymer may have 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 99.7 mol %. A block character of ethylene units in the ethylene-vinyl alcohol copolymer may be 0.90 to 0.99. Such an ethylene-vinyl alcohol copolymer may have excellent high-speed coating ability and water-resistant adhesiveness, particularly when being used as an adhesive.

Ethylene-vinyl alcohol copolymer, method for producing same, and use thereof

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&#xb0; C.) at 30&#xb0; C. and a crystallinity in water Cw (70&#xb0; C.) at 70&#xb0; 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.

Ethylene-vinyl alcohol copolymer particles, method for producing same and use of same

The present invention provides an aqueous solution containing an ethylene-vinyl alcohol copolymer (A), an alcohol (B) having 1 to 4 carbon atoms and water (C), wherein an ethylene unit content of the ethylene-vinyl alcohol copolymer (A) is 1 mol % or more and less than 20 mol %; a crystallinity in water Cw (30&#xb0; C.) at 30&#xb0; C. and a crystallinity in water Cw (70&#xb0; C.) at 70&#xb0; C. as determined by pulse NMR satisfy Formula (I); the ethylene-vinyl alcohol copolymer (A) is contained in 0.1 to 100 parts by mass based on 100 parts by mass of water (C); and the alcohol (B) is contained in 0.01 to 30 parts by mass based on 100 parts by mass of water (C). Thus, there is provided an aqueous solution of an ethylene-vinyl alcohol copolymer, which forms a less number of lumps and generates a reduced amount of fibrillar precipitate even when a shear stress is applied. 

Ethylene-vinylalcohol copolymer aqueous solution

The present invention provides an aqueous emulsion excellent in heat resistance, water resistance (particularly, hot water resistance and boiling resistance), and viscosity stability. The present invention also provides an adhesive containing the aqueous emulsion, forming an adhesive layer resistant to staining, and ensuring a high level of safety. The present invention relates to an aqueous emulsion containing an ethylenically unsaturated monomer unit-containing polymer (A) as a dispersoid and vinyl alcohol polymer (B) as a dispersant, wherein, the ethylenically unsaturated monomer unit-containing polymer (A) includes a structural unit derived from a radical-polymerizable ethylenically unsaturated monomer (a) having a functional group represented by the following general formula (W), and the degree of saponification of the vinyl alcohol polymer (B) is 80 mol % or more: 

Aqueous emulsion and adhesive using same

A modified vinyl alcohol polymer powder having a structural unit derived from a derivative of an ethylenically unsaturated dicarboxylic acid, and containing a reduced amount of methanol, and a trace amount of a component that does not dissolve in water. The present invention relates to a modified vinyl alcohol polymer powder containing a structural unit derived from a derivative (A) of an ethylenically unsaturated dicarboxylic acid in a content (X) of 0.05 mol % or more and 10 mol % or less, and having a degree of saponification of 80.0 mol % or more and 99.9 mol % or less, the modified vinyl alcohol polymer powder has a methanol content of 0.01 weight % or more and less than 3.0 weight %, the modified vinyl alcohol polymer powder contains 0.1 ppm or more and less than 2,000 ppm of a component that is insoluble in a 90&#xb0; C., 5 weight % aqueous solution.

Modified vinyl alcohol polymer powder having reduced methanol content and production method therefor, and water-soluble film and packaging material

The present invention provides an aqueous emulsion composition excellent in heat resistance, water resistance, hot water resistance, boiling water resistance, and viscosity stability and also excellent in stain resistance. The present invention relates to an aqueous emulsion composition including an aqueous emulsion (D) and a cyclic acid anhydride (E). The aqueous emulsion (D) includes a polymer (X) having an ethylenically unsaturated monomer (B), a polyvinyl alcohol resin (A), and water. At least one selected from the polyvinyl alcohol resin (A) and the polymer (X) has, in a main chain thereof, a structural unit derived from a monomer (C) represented by the following formula (I), (II), (III), or (IV).  (The definitions of the symbols in the formulae are omitted.)

Aqueous emulsion composition

Provided is a vinyl alcohol-based copolymer, obtained by saponifying a copolymer of vinyl acetate and a polyfunctional monomer, wherein the polyfunctional monomer contains two or more ethylenic double bonds in its molecule, the vinyl alcohol-based copolymer has a side chain containing an ethylenic double bond and a molar ratio (d) of the ethylenic double bond to a total of vinyl alcohol units and vinyl acetate units is from 0.05/100 to 2/100, and the vinyl alcohol-based copolymer is water soluble.

Vinyl alcohol copolymer and method for producing same

The present invention provides: a water-soluble film that is superior in cold water solubility and in practical properties such as strength and stiffness and that can resist deterioration in various properties such as chemical resistance over time; and a modified polyvinyl alcohol used for the water-soluble film. The present invention relates to a modified polyvinyl alcohol containing 0.05 to 10 mol % of a monomer unit having two carboxyl groups. InH-NMR spectroscopy of the modified polyvinyl alcohol, an integral (X) from 6.8 to 7.2 ppm and an integral (Y) from 5.3 to 5.5 ppm satisfy the following expression:0.60&#x2264;/()&#x3c;1.0.

Modified polyvinyl alcohol and water-soluble film

There is provided a vinyl alcohol-based polymer having an ethylenic double bond with a saponification degree of 70 mol % or more, wherein the vinyl alcohol-based polymer is water-soluble; a molar ratio of the ethylenic double bond to the total of vinyl alcohol units and vinyl acetate units is 0.05/100 to 2/100; and a limiting viscosity [&#x3b7;] and a weight-average molecular weight Mw of a vinyl ester-based polymer which is produced by esterifying the vinyl alcohol-based polymer satisfy the following formulas (1) and (2).4.7&#x2264;log Mw 6.3&#x2003;&#x2003;(1)0.60&#x3c;(log [&#x3b7;]+3.75)/log Mw&#x3c;0.69&#x2003;&#x2003;(2)

Vinyl alcohol polymer and use thereof

Provided is a modified polyvinyl alcohol containing 0.1 to 10 mol % of a monomer unit represented by formula (1) below and having a degree of polymerization exceeding 2000. This provides a modified polyvinyl alcohol an aqueous solution of which foams less and which has excellent film strength and gas barrier properties under high humidity conditions, while having excellent water solubility. [In formula (), Rrepresents a hydrogen atom or a methyl group.]

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Kurashiki, Japan

Tatsuya Tanida