Molded article of crystalline thermoplastic resin with high gas barrier property and production thereof

A molded article of crystalline thermoplastic resin with high gas barrier property of which the resin has crystalline and non-crystalline regions, wherein the crystal molecular chain axis direction of the crystalline regions orients uniaxially and uniplanarly, wherein the crystallites orientation is characterized by the following (a) and (b):

• (a) the degree of the uniaxial orientation of the crystal molecular chain axis direction is less than 60.degree. in the half-height width of the longitudinal peak, and
• (b) the degree of the uniaxial-uniplanar orientation of the crystal plane which orients in the direction perpendicular to the molecular chain axis is more than 3 in terms of the equatorial intensity ratio, said crystal plane being characteristic of the individual resin, and wherein the molded article is further annealed to increase the crystallinity of the resin.

A method of making a crystalline thermoplastic resin molded article with high gas barrier property of which the resin has crystalline and non-crystalline regions, said method comprising orienting the crystal molecular chain axis direction of crystallites of the crystalline regions uniaxially and uniplanarly under a temperature lower than the melting point of the crystalline regions and higher than the glass transition point of the non-crystalline regions by a method for achieving such uniaxial-uniplanar crystallites orientation, such that;

• (a) the degree of the uniaxial orientation of the crystal molecular chain axis direction is less than 60.degree. in the half-height width of the longitudinal peak, and
• (b) the degree of the uniaxial-uniplanar orientation of the crystal plane which orients in the direction perpendicular to the molecular chain axis is more than 3 in terms of the equatorial intensity ratio, said crystal plane being characteristic of the individual resin.

A method of making a crystalline thermoplastic resin molded article with high gas barrier property of which the resin has crystalline and non-crystalline regions, said method comprising orienting the crystal molecular chain axis direction of crystallites of the crystalline regions uniaxially and uniplanarly under a temperature lower than the melting point of the crystalline regions and higher than the glass transition point of the non-crystalline regions by a method for achieving such uniaxial-uniplanar crystallites orientation, such that;

• (a) the degree of the uniaxial orientation of the crystal molecular chain axis direction is less than 60.degree. in the half-height width of the longitudinal peak, and
• (b) the degree of the uniaxial-uniplanar orientation of the crystal plane which orients in the direction perpendicular to the molecular chain axis is more than 3 in terms of the equatorial intensity ratio, said crystal plane being characteristic of the individual resin, and further annealing the molded article to increase the crystallinity of the resin, and increasing the crystallinity of the resin by a method for increasing the proportion of the crystalline regions of the resin.