Abstract: The invention provides pellets of a saponified ethylene-vinyl acetate copolymer which are excellent in feedability, cause little fluctuation of extruder torque or discharge during molding, and yield shaped articles with high dimensional accuracy such as the high accuracy of form and thickness. The pellets of the invention are such that the differential curve representing the magnitude of change in the cumulative pore volume curve generated by measuring the fractional volume of surface pores by the mercury intrusion method has no peak within the pore diameter range of 1×102˜1×104 Å.

Abstract: The method of treating a saponified ethylene vinyl acetate copolymer (A) with an acid (B) and/or its salt (C) which comprises feeding a saponified ethylene-vinyl acetate copolymer (A′) in which the acid (B) and/or salt (C) has been incorporated in advance to a column reactor from its top, simultaneously feeding an aqueous solution of the acid (B) and/or salt (C) from the bottom of the reactor to thereby effect a countercurrent contact of (A′) with the aqueous solution of (B) and/or (C), withdrawing the excess of the aqueous solution of acid (B) and/or salt (C) from the reactor top, and continuously withdrawing the treated saponified ethylene-vinyl acetate copolymer from the reactor bottom.

Abstract: An aqueous solution of partially hydrolyzed vinyl ester resin having an excellent stability and useful particularly as a secondary agent for suspension polymerization of vinyl compounds, wherein the partially hydrolyzed vinyl ester resin has a degree of hydrolysis of at most 70% by mole, it is contained in a concentration of at most 50% by weight, and it satisfies the equation: 1n y>0.042x+1.0, in which y is the cloud point (° C.) of a 30% by weight aqueous solution of the partially hydrolyzed vinyl ester resin, and x is the degree of hydrolysis (% by mole) of the partially hydrolyzed vinyl ester resin.

Abstract: A resin composition comprising a saponified ethylene-vinyl acetate copolymer (A), a polyamide resin having a melting point not exceeding 160° C. (B), and a small proportion of a boron compound (C) and a laminate comprising a multi-lamellar shaped article comprised of the above resin composition layer (X) and a thermoplastic resin layer (Y).

Abstract: The invention provides a process for producing a saponified vinyl acetate polymer (a saponified ethylene-vinyl acetate copolymer in particular) which features a minimum of coloration of molding pellets, a well-inhibited emanation of an odor in melt-molding, a high transparency of the product film and a low incidence of fish-eyes in the film, and a process for producing a vinyl acetate polymer (particularly an ethylene-vinyl acetate copolymer) for use as the starting material for said saponified vinyl acetate polymer having said favorable properties. In accordance with the invention, either vinyl acetate alone or vinyl acetate and one or more other monomers are polymerized in the presence of a hydroxylactone compound and a polymerization catalyst. The resulting vinyl acetate polymer (particularly the ethylene-vinyl acetate copolymer) is then saponified.

Abstract: A method of drying saponified ethylene-vinyl acetate copolymers which includes melting and kneading a mixture including one or more saponified ethylene-vinyl acetate copolymer species and having a water content of 5 to 60% by weight until the mixture has a water content of less then 5% by weight.

Abstract: A saponified ethylene-vinyl acetate copolymer is characterized in that, in the relationship between the heating time and the extrusion rate as measured with a Koka flow tester at at least one temperature higher by 10-80° C. than the melting point thereof, it shows an extrusion rate at any time within the period of 15 minutes to 2 hours of heating which is 0.1-50 times the extrusion rate at 15 minutes of heating and an extrusion rate at any time within the period of 2-10 hours of heating which is less than 2 times the extrusion rate at 15 minutes of heating and that, in the relationship between the heating time and the torque at at least one temperature higher by 30-60° C. than the melting point, it shows, at any time within the range of 1-2 hours of heating, a toruque value within the range of ⅙ to ⅚ of the maximum torque value found within the initial 20 minutes of heating.

Abstract: A resin composition comprising a saponified ethylene-vinyl acetate copolymer (A) and a metal soap (B) of the general formula (1) obtained by an acid with a group 2 metal oxide or hydroxide. &agr;MO.M(OOCR)2  (1) wherein &agr; represents a numerical value of 0.1˜1.0; M represents a bivalent metal belonging to Group 2 of Periodic Table of the Elements; R represents a saturated or unsaturated alkyl group containing 11˜29 carbon atoms.

Abstract: A method of producing silicone-containing aqueous coating compositions excellent in shelf stability of the emulsion and in weather resistance, stain resistance, water resistance and solvent resistance of coatings derived therefrom is provided. The method comprises subjecting an aqueous emulsion prepared in advance by emulsification in an aqueous medium containing a polyalkoxypolysiloxane (A), an unsaturated monomer (B) and an emulsifier (C) so as to attain an oil droplet diameter not more than 1,000 nm to polymerization in the presence of a polymerization initiator (D).

Abstract: The method of treating a saponified ethylene vinyl acetate copolymer (A) with an acid (B) and/or its salt (C) which comprises feeding a saponified ethylene-vinyl acetate copolymer (A′) in which the acid (B) and/or salt (C) has been incorporated in advance to a column reactor from its top, simultaneously feeding an aqueous solution of the acid (B) and/or salt (C) from the bottom of the reactor to thereby effect a countercurrent contact of (A′) with the aqueous solution of (B) and/or (C), withdrawing the excess of the aqueous solution of acid (B) and/or salt (C) from the reactor top, and continuously withdrawing the treated saponified ethylene-vinyl acetate copolymer from the reactor bottom.

Abstract: The saponified ethylene-vinyl acetate copolymer (EVOH) resin composition of the present invention is a composition comprising a saponified ethylene-vinyl acetate copolymer (EVOH) (A) having an ethylene content of 20-60 mole percent and a saponification degree of not less than 90 mole percent, magnesium acetate or/and calcium acetate (B) as an essential component and at least one of acetic acid (C), a boron compound (D) and sodium acetate (E) as an optional component, and is characterized in that the contents of the respective components in said composition, relative to 100 parts by weight of EVOH (A), are as follows: magnesium acetate or/and calcium acetate (B) 0.001-0.02 part by weight on the metal basis; acetic acid (C) 0-0.05 part by weight; the boron compound (D) 0-1 part by weight on the boron basis; and sodium acetate (E) 0-0.1 part by weight on the metal basis; and that the weight loss when said composition is maintained at a temperature (T+70)° C. higher by 70 ° C.

Abstract: A resin composition is provided which comprises (A) a saponified ethylene-vinyl acetate copolymer (referred to as EVOH for short) with an ethylene content of 20 to 60 mole percent and a saponification degree of not less than 90 mole percent, and contains therein (B) a boron compound as an essential component, (C) acetic acid as an optional component, and at least one compound selected from among (D) an acetic acid salt and (E) a phosphoric acid compound as an essential component, the contents of the respective additive components per 100 parts by weight of EVOH (A) being as follows: boron compound (B): 0.001 to 1 part by weight on the boron basis; acetic acid (C): 0 to 0.05 part by weight; acetic acid salt (D): 0.001 to 0.05 part by weight on the metal basis; and phosphoric acid compound (E): 0.0005 to 0.05 part by weight on the phosphate radical basis.

Abstract: A dispersing stabilizer suitable for suspension polymerization of vinyl chloride or a monomer mixture mainly composed of vinyl chloride which can be used in a hot water charging polymerization process without any problems, and which can produce vinyl chloride homopolymer or copolymers having a good porosity, a large bulk density, a very low content of coarse particles and good physical properties, the dispersing stabilizer comprising a polyvinyl alcohol having a degree of hydrolysis of 75 to 85% by mole, an absorbance of not less than 0.1 measured at a wavelength of 280 m.mu.with respect to the 0.1% by weight aqueous solution, a content of carboxyl group of 0.01 to 0.15% by mole and a cloud point of not less than 50.degree. C. measured with respect to the 0.

Abstract: A purging agent for purging the resin to be purged from an extruder in a melt extrusion apparatus is provided which comprises (A) a hydrophobic thermoplastic resin, (B) a hydrophilic thermoplastic resin and (C) a purging auxiliary selected from the group consisting of (C1) a plasticizer for the resin to be purged, (C2) water and (C3) a crystal water-containing compound, the proportions of the hydrophobic thermoplastic resin (A) and hydrophilic thermoplastic resin (B) being 100/0 to 30/70 by weight and the proportion of the purging auxiliary (C) relative to 100 weight parts of the sum total of the hydrophobic thermoplastic resin (A) plus hydrophilic thermoplastic resin (B) being 0.01 to 40 weight parts.

Abstract: A laminate having an excellent gas barrier property and an improved organic solvent resistance and suitable for use in containers for chemicals and volatile materials such as organic solvents and fuels. The laminate comprises:(A) a layer comprising (A1) a hydrolyzed ethylene-vinyl acetate copolymer having an ethylene content of 10 to 70% by mole and a degree of hydrolysis of at least 85% by mole,(B) a layer of a resin composition comprising (B1) a polyolefin resin and (B2) 0.

Abstract: A dispersing stabilizer including (A) a polyvinyl alcohol resin containing oxyalkylene groups and having a surface tension of 35 to 55 dyne/cm at 20.degree. C. as a 1% by weight aqueous solution, or said resin and (B) a water-soluble polymer or a polyvinyl alcohol resin having a low degree of hydrolysis and a low degree of polymerization. When using the dispersing stabilizer of the present invention, both of a porosity and a bulk density of a polyvinyl resin particle can be improved at the same time, and, in addition, a distribution of particle size and a uniformity of porosity can be further improved.

Abstract: A dispersing stabilizer suitable for suspension polymerization of vinyl chloride or a monomer mixture mainly composed of vinyl chloride which can be used in a hot water charging polymerization process without any problems, and which can produce vinyl chloride homopolymer or copolymers having a good porosity, a large bulk density, a very low content of coarse particles and good physical properties, the dispersing stabilizer comprising a polyvinyl alcohol having a degree of hydrolysis of 75 to 85% by mole, an absorbance of not less than 0.1 measured at a wavelength of 280 m.mu. with respect to the 0.1% by weight aqueous solution, a content of carboxyl group of 0.01 to 0.15% by mole and a cloud point of not less than 50.degree. C. measured with respect to the 0.1% by weight aqueous solution.

Abstract: A saponified ethylene-vinyl acetate copolymer is oxidation-treated in solution in a solvent mixture of water and alcohol in the presence of hydrogen peroxide and a polyvalent metal salt to provide an oxidation-treated polymer solution. This oxidation-treated polymer solution is coated on a substrate, e.g. a polymer film, to provide a laminate.

Abstract: The invention provides an oxyalkylene group-containing PVA resin composition with an alkali metal acetate content of 0.001.about.1 weight % and an oxyalkylene group-containing PVA resin composition with an alkali metal acetate content of 0.001.about.1 weight %, which further contains 0.1.about.10 moles of an acid with a pKa value of not more than 5.0 per mole of the alkali metal acetate, optionally together with 0.01.about.5 weight of a phenol compound which melts at 50.degree..about.250.degree. C., a thioether or a phosphite based on the polyvinyl alcohol and/or 0.01.about.3 weight % of a fatty acid compound based on the polyvinyl alcohol.

Abstract: The invention relates to a polyvinyl acetate resin composition comprising a hydrophilic polyvinyl acetate resin rendered soluble or dispersible in water by partial saponification or introduction of hydrophilic groups (A), a hydroxy fatty acid compound of not less than 6 carbon atoms (B) and a plasticizer (C).