Abstract: The present invention relates to a resin composition having an ethylene-vinyl alcohol copolymer (EVOH) component and a multi-layered structure containing the resin composition.

Abstract: The present invention relates to a resin composition having an ethylene-vinyl alcohol copolymer (EVOH) component and a multi-layered structure containing the resin composition.

Abstract: The present invention relates to a resin composition having an ethylene-vinyl alcohol copolymer (EVOH) component and a multi-layered structure containing the resin composition.

Abstract: A process for producing an ethylene-vinyl alcohol copolymer resin, including feeding EVOH into an extruder, keeping the temperature of the melting resin in the extruder at 70 to 170° C., adjusting the amount of water in the extruder so that the water content right after being discharged from the extruder is 5 to 40 weight %, and extruding out the EVOH resin. The extruded EVOH resin is cut into EVOH pellets. Thereby, it is possible to obtain resin pellets in which no spherocrystals are observed in the center of the cross section of the resin when the cross section is observed by the use of a polarization microscope, or no lubricant is contained in the resin pellets, and the angle of repose is 23° or less when the resin pellets are laminated.

Abstract: A method for producing an ethylene-vinyl alcohol copolymer resin composition, said method comprising: (a) introducing into an extruder an ethylene-vinyl alcohol copolymer having a water content of at least 0.5 wt %; (b) further introducing into said extruder a liquid component comprising an aqueous solution of a resin, an aqueous dispersion of a resin, an aqueous dispersion of inorganic fine particles, or a mixture thereof; (c) subjecting said copolymer and said component to melt-kneading in said extruder; and (d) discharging the resulting ethylene-vinyl alcohol copolymer resin composition from the extruder. This method improves the dispersibility of a resin and/or inorganic fine particles in the EVOH while suppressing thermal deterioration of the EVOH.

Abstract: This invention provides a method for producing a saponified ethylene-vinyl acetate copolymer in which visible imperfections (particularly fish eyes) of the saponified copolymer is inhibited. In this invention, a mixture solution is prepared by adding water to a methanol solution after saponifying an ethylene-vinyl acetate copolymer, and insoluble materials are removed from this mixture solution. Various types of filter or centrifugal separator are used to remove insoluble materials. It is preferable that the weight ratio of methanol to water is from 5:5 to 9:1, the concentration of the saponified copolymer is from 30 to 60 wt %, and the temperature is from 55 to 80° C. This method is particularly suitable for producing a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20 to 70 mol % and a saponification degree of at least 95 mol %.

Abstract: Disclosed are a resin composition comprising an ethylene-vinyl alcohol copolymer and a multi-layered structure comprising the resin composition. The resin composition comprises an ethylene-vinyl alcohol copolymer, and is characterized in that, when it is heated in a nitrogen atmosphere at 220° C., its MFR (at 230° C. under a load of 10.9 kg) shows a minimum value within 10 hours after the start of heating it, and shows a maximum value (MFRmax) within 100 hours after showing its minimum value, that it contains from 0.05 to 4 ?mols/g of a carboxylic acid (A), and that it satisfies the following formulae (1) and (2): 0.5?MFRmax/MFR0?45 ??(1) 0.1?(a1)/(A)?1.0 ??(2) wherein MFRmax indicates the maximum value of MFR (at 230° C. under a load of 10.9 kg) of the resin composition heated in a nitrogen atmosphere at 220° C.; MFR0 indicates MFR (at 230° C under a load of 10.

Abstract: The present invention relates to a method of producing an ethylene-vinyl alcohol copolymer resin.

Abstract: A method for producing a saponified ethylene-vinyl acetate copolymer (EVOH) comprises: supplying into a second reactor a solution containing the copolymer that is saponified partially with an alkali catalyst under a predetermined pressure in a first reactor; and saponifying further the partially-saponified copolymer in the second reactor under a pressure higher than the predetermined pressure in the first reactor. According to the method, an EVOH having a high saponification degree can be produced efficiently with a small amount of alkali catalyst.

Abstract: The present invention provides a method for producing an ethylene-vinyl alcohol copolymer resin composition, said method comprising: a) introducing into an extruder an ethylene-vinyl alcohol copolymer resin having a water content of at least 0.5 weight % and an additional component; b) kneading the resin and the additional component whereby to form an ethylene-vinyl alcohol copolymer resin composition; and c) discharging said resin composition from the extruder; wherein said method further comprises feeding water in a liquid state to the extruder and/or removing water in a liquid state from the extruder. Thereby, strand-breakage or cutting errors are suppressed and thus, molded products such as pellets can be provided with a stable shape.

Abstract: A process for producing an ethylene-vinyl alcohol copolymer resin, including feeding EVOH into an extruder, keeping the temperature of the melting resin in the extruder at 70 to 170° C., adjusting the amount of water in the extruder so that the water content right after being discharged from the extruder is 5 to 40 weight %, and extruding out the EVOH resin. The extruded EVOH resin is cut into EVOH pellets. Thereby, it is possible to obtain resin pellets in which no spherocrystals are observed in the center of the cross section of the resin when the cross section is observed by the use of a polarization microscope, or no lubricant is contained in the resin pellets, and the angle of repose is 23° or less when the resin pellets are laminated.

Abstract: A process for producing an ethylene-vinyl alcohol copolymer resin, including feeding EVOH into an extruder, keeping the temperature of the melting resin in the extruder at 70 to 170° C., adjusting the amount of water in the extruder so that the water content right after being discharged from the extruder is 5 to 40 weight %, and extruding out the EVOH resin. The extruded EVOH resin is cut into EVOH pellets. Thereby, it is possible to obtain resin pellets in which no spherocrystals are observed in the center of the cross section of the resin when the cross section is observed by the use of a polarization microscope, or no lubricant is contained in the resin pellets, and the angle of repose is 23° or less when the resin pellets are laminated.

Abstract: This invention provides a method for producing a saponified ethylene-vinyl acetate copolymer in which visible imperfections (particularly fish eyes) of the saponified copolymer is inhibited. In this invention, a mixture solution is prepared by adding water to a methanol solution after saponifying an ethylene-vinyl acetate copolymer, and insoluble materials are removed from this mixture solution. Various types of filter or centrifugal separator are used to remove insoluble materials. It is preferable that the weight ratio of methanol to water is from 5:5 to 9:1, the concentration of the saponified copolymer is from 30 to 60 wt %, and the temperature is from 55 to 80° C. This method is particularly suitable for producing a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20 to 70 mol % and a saponification degree of at least 95 mol %.

Abstract: This invention provides a method for producing a saponified ethylene-vinyl acetate copolymer in which visible imperfections (particularly fish eyes) of the saponified copolymer is inhibited. In this invention, a mixture solution is prepared by adding water to a methanol solution after saponifying an ethylene-vinyl acetate copolymer, and insoluble materials are removed from this mixture solution. Various types of filter or centrifugal separator are used to remove insoluble materials. It is preferable that the weight ratio of methanol to water is from 5:5 to 9:1, the concentration of the saponified copolymer is from 30 to 60 wt %, and the temperature is from 55 to 80° C. This method is particularly suitable for producing a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20 to 70 mol % and a saponification degree of at least 95 mol %.

Abstract: A method for producing an aqueous ethylene-vinyl alcohol copolymer (EVOH) composition that ensures efficient removal of alcohol not worsening the environment in and around working areas, and which provides EVOH pellets of the aqueous composition, which can be produced stably and can be washed rapidly, the method involving introducing an EVOH solution that contains at least 50 parts by weight, relative to 100 parts by weight of EVOH therein, of an alcohol having a boiling point of not higher than 100° C., into a vessel, and contacting it with water vapor in the vessel, thereby letting the alcohol out along with water vapor and taking the resulting aqueous EVOH composition that contains from 0 to 10 parts by weight of the alcohol and from 10 to 500 parts by weight of water, relative to 100 parts by weight of EVOH therein, out of the vessel; and the EVOH pellets obtained by cutting the aqueous EVOH composition obtained in the method.

Abstract: The present invention relates to a resin composition having an ethylene-vinyl alcohol copolymer (EVOH) component and a multi-layered structure containing the resin composition.

Abstract: In the present invention, particles of an ethylene-vinyl alcohol copolymer (EVOH) are contacted with a solution containing a boron compound, whereby to obtain a substantially homogeneous distribution of the boron compound within the particles. For example, EVOH and the solution are continuously fed into a treatment apparatus and brought into contact with each other in the treatment apparatus, and the EVOH when continuously removed from the apparatus is in contact with the solution containing the boron compound in a concentration of at least 0.7 times but not more than 1.3 times a solution equilibrium concentration.

Abstract: A method for producing a saponified ethylene-vinyl acetate copolymer (EVOH) comprises: supplying into a second reactor a solution containing the copolymer that is saponified partially with an alkali catalyst under a predetermined pressure in a first reactor; and saponifying further the partially-saponified copolymer in the second reactor under a pressure higher than the predetermined pressure in the first reactor. According to the method, an EVOH having a high saponification degree can be produced efficiently with a small amount of alkali catalyst.

Abstract: A method for producing an ethylene-vinyl alcohol copolymer resin composition, said method comprising: (a) introducing into an extruder an ethylene-vinyl alcohol copolymer having a water content of at least 0.5 wt %; (b) further introducing into said extruder a liquid component comprising an aqueous solution of a resin, an aqueous dispersion of a resin, an aqueous dispersion of inorganic fine particles, or a mixture thereof; (c) subjecting said copolymer and said component to melt-kneading in said extruder; and (d) discharging the resulting ethylene-vinyl alcohol copolymer resin composition from the extruder. This method improves the dispersibility of a resin and/or inorganic fine particles in the EVOH while suppressing thermal deterioration of the EVOH.

Abstract: The present invention provides a method for producing an ethylene-vinyl alcohol copolymer resin composition, said method comprising: a) introducing into an extruder an ethylene-vinyl alcohol copolymer resin having a water content of at least 0.5 weight % and an additional component; b) kneading the resin and the additional component whereby to form an ethylene-vinyl alcohol copolymer resin composition; and c) discharging said resin composition from the extruder; wherein said method further comprises feeding water in a liquid state to the extruder and/or removing water in a liquid state from the extruder. Thereby, strand-breakage or cutting errors are suppressed and thus, molded products such as pellets can be provided with a stable shape.