Abstract: A polyester resin composition is produced by melt-kneading a mixture comprising a polyamide resin and a polyester resin, and a tricarboxylic acid compound. The polyamide resin is a polymerization product of a diamine component containing 70 mol % or more of m-xylylenediamine and a dicarboxylic acid component containing 70 mol % or more of adipic acid. The polyester resin is a polymerization product of a dicarboxylic acid component containing 70 mol % or more of an aromatic dicarboxylic acid and a diol component containing 70 mol % or more of an aliphatic diol. The incorporation of a tricarboxylic acid compound such as aromatic tricarboxylic acids and their anhydrides improves transparency and whitening resistance at moisture absorbing of films, sheets and thin-wall hollow containers without deteriorating their gas barrier properties.

Abstract: A polyamide resin composition comprising 100 parts by weight of a polyamide resin and 0.005 to 1.0 part by weight of at least one compound selected from the group consisting of a metal salt of a fatty acid, a diamide compound and a diester compound. The polyamide resin is obtained by solid phase-polymerizing a polyamide resin prepared by melt-polymerizing a diamine component containing 70 mol % or more of metaxylylenediamine and a dicarboxylic acid component containing 70 mol % or more of adipic acid, and preferably has a relative viscosity of 2.3 to 4.2 when measured at 25.degree. C. using a solution of 1 g polyamide resin in 100 ml of 96% sulfuric acid.

Abstract: A polyamide resin composition obtained by melting and kneading(A) a first polyamide containing not less than 90 mol %, based on the total recurring units, of a m-xylylene adipamide unit of the formula, ##STR1## and (B) a second polyamide showing a semicrystallization time of not more than 30 seconds in a constant-temperature crystallization at 160.degree. C. and having a solubility parameter in the range of 13.+-.1.5;(C) under the conditions where the following relationship is satisfied,(0.025C-2.2).ltoreq.log R.ltoreq.(0.025C-0.5)wherein C is a proportion (wt. %) of the first polyamide based on the total weight of the first and second polyamides, and R is a ratio of the melt viscosity of the first polyamide to the melt viscosity of the second polyamide at a temperature higher by 20.degree. C. than the melting point of that one of the first and second polyamides which has a higher melting point than the other, provided that C is in the range of 20 to 95 (wt. %);and a film produced therefrom.