A method for producing a polyvinyl alcohol resin having an absorbance of not less than 0.2 at 280 nm, which includes: melt-kneading a polyvinyl alcohol resin material; extruding the resulting melt-kneaded polyvinyl alcohol resin into a sheet; cooling the resulting polyvinyl alcohol resin sheet; and pulverizing the cooled polyvinyl alcohol resin sheet. The method ensures a higher productivity and an excellent long-run property.

There is provided a co-injection molded multilayer structure comprising a barrier layer and outer layers laminated to contact with the barrier layer on its both sides, wherein the barrier layer is made of a resin composition (X) comprising an ethylene-vinyl alcohol copolymer (A) and an alkali metal salt (B) of a higher fatty acid, having a melting point of 250° C. or lower; the ethylene-vinyl alcohol copolymer (A) has an ethylene unit content of 20 to 60 mol % and a saponification degree of 90% or more, and a content of the alkali metal salt (B) in the barrier layer is 50 to 1500 ppm in terms of metal atoms; and the outer layers are made of a resin composition (Y) comprising an unmodified high-density polyethylene (F) and a maleic anhydride-modified polyethylene (G), and a maleic anhydride modification rate relative to the whole resin composition (Y) is 0.005 to 0.1 wt %. This co-injection molded multilayer structure has excellent adhesiveness, so that its oxygen barrier performance can be maintained even after being subjected to an impact due to falling or the like.

There is provided a co-injection molded multilayer structure comprising a barrier layer and outer layers laminated to contact with the barrier layer on its both sides, wherein the barrier layer is made of a resin composition (X) comprising an ethylene-vinyl alcohol copolymer (A) and an alkali metal salt (B) of a higher fatty acid, having a melting point of 250° C. or lower; the ethylene-vinyl alcohol copolymer (A) has an ethylene unit content of 20 to 60 mol % and a saponification degree of 90% or more, and a content of the alkali metal salt (B) in the barrier layer is 50 to 1500 ppm in terms of metal atoms; and the outer layers are made of a resin composition (Y) comprising an unmodified high-density polyethylene (F) and a maleic anhydride-modified polyethylene (G), and a maleic anhydride modification rate relative to the whole resin composition (Y) is 0.005 to 0.1 wt %. This co-injection molded multilayer structure has excellent adhesiveness, so that its oxygen barrier performance can be maintained even after being subjected to an impact due to falling or the like.

Provided is a thermoplastic elastomer composition which does not undergo viscosity increase during melt molding, gelation and molding failure, while having excellent heat resistance and durability. A thermoplastic elastomer composition for tires, which contains (A) an ethylene-vinyl alcohol copolymer or a modified ethylene-vinyl alcohol copolymer, (B) a thermoplastic resin or a thermoplastic elastomer, which has a melting point of 200° C. or higher, and (C) an acid-modified elastomer in an amount of 20% by volume or more based on the amount of all polymer components. This thermoplastic elastomer composition for tires is characterized in that if this thermoplastic elastomer composition for tires is extruded at a piston speed of 5 min/min at a temperature that is higher than the melting point of the thermoplastic resin or thermoplastic elastomer (B) by 20° C. in a viscosity measurement by means of a capillary rheometer, the viscosity η.sub.2 in 800 seconds after the start of the extrusion is less than 120% of the viscosity η.sub.1 in 200 seconds after the start of the extrusion.

Provided is a thermoplastic elastomer composition which does not undergo viscosity increase during melt molding, gelation and molding failure, while having excellent heat resistance and durability. A thermoplastic elastomer composition for tires, which contains (A) an ethylene-vinyl alcohol copolymer or a modified ethylene-vinyl alcohol copolymer, (B) a thermoplastic resin or a thermoplastic elastomer, which has a melting point of 200° C. or higher, and (C) an acid-modified elastomer in an amount of 20% by volume or more based on the amount of all polymer components. This thermoplastic elastomer composition for tires is characterized in that if this thermoplastic elastomer composition for tires is extruded at a piston speed of 5 min/min at a temperature that is higher than the melting point of the thermoplastic resin or thermoplastic elastomer (B) by 20° C. in a viscosity measurement by means of a capillary rheometer, the viscosity η.sub.2 in 800 seconds after the start of the extrusion is less than 120% of the viscosity η.sub.1 in 200 seconds after the start of the extrusion.

Provided is a thermoplastic elastomer composition which does not undergo viscosity increase during melt molding, gelation and molding failure, while having excellent heat resistance and durability. A thermoplastic elastomer composition for tires, which contains (A) an ethylene-vinyl alcohol copolymer or a modified ethylene-vinyl alcohol copolymer, (B) a thermoplastic resin or a thermoplastic elastomer, which has a melting point of 200° C. or higher, and (C) an acid-modified elastomer in an amount of 20% by volume or more based on the amount of all polymer components. This thermoplastic elastomer composition for tires is characterized in that if this thermoplastic elastomer composition for tires is extruded at a piston speed of 5 min/min at a temperature that is higher than the melting point of the thermoplastic resin or thermoplastic elastomer (B) by 20° C. in a viscosity measurement by means of a capillary rheometer, the viscosity η.sub.2 in 800 seconds after the start of the extrusion is less than 120% of the viscosity η.sub.1 in 200 seconds after the start of the extrusion.

Provided is a preparation method of a coating material. The method includes: using an aluminum salt and a silicon source as precursors; and performing hydrothermal crystallization and calcination treatments successively under an action of a template agent to obtain the coating material, wherein the template agent is used to cause the coating material to form a porous spherical structure. In the embodiments of the present disclosure, the preparation process of the coating material is simple and the cost is low, and the specific surface area of the prepared coating material is large.

Provided is a preparation method of a coating material. The method includes: using an aluminum salt and a silicon source as precursors; and performing hydrothermal crystallization and calcination treatments successively under an action of a template agent to obtain the coating material, wherein the template agent is used to cause the coating material to form a porous spherical structure. In the embodiments of the present disclosure, the preparation process of the coating material is simple and the cost is low, and the specific surface area of the prepared coating material is large.

Disclosed is a support material for a fused deposition modeling. The support material has excellent adhesion to a variety of model materials and is easily dissolved and removed by washing with water. Also, the waste liquid (PVA-based aqueous solution) generated after the washing operation may be allowed to be drained as it is, in compliance with environmental regulations. The support material comprises (A) PVA-based resin having a group containing sulfonic acid or a salt thereof and (B) biodegradable polyester. The (A) PVA-based resin having a group containing sulfonic acid or a salt thereof and (B) biodegradable polyester have a sea-island structure in which one is dispersed in the other as a matrix.

Disclosed is a support material for a fused deposition modeling. The support material has excellent adhesion to a variety of model materials and is easily dissolved and removed by washing with water. Also, the waste liquid (PVA-based aqueous solution) generated after the washing operation may be allowed to be drained as it is, in compliance with environmental regulations. The support material comprises (A) PVA-based resin having a group containing sulfonic acid or a salt thereof and (B) biodegradable polyester. The (A) PVA-based resin having a group containing sulfonic acid or a salt thereof and (B) biodegradable polyester have a sea-island structure in which one is dispersed in the other as a matrix.