| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyamide film which can realize high-speed casting with excellent productivity, can be stretched, contains little low-molecular components formed and is excellent in strength by incorporating a specified polyester copolymer into polyamide. SOLUTION: A polyamide (A), preferably one having a relative viscosityηr in 98% sulfuric acid of 2.0 to 6.0, is mixed with 0.1-50wt.% copolyester (B) having a melt viscosityηof 0.1-50Pa.sec and containing 5-75mol% mesogen groups in the principal chain to give a polyamide film for stretching. It is desirable that the melt viscosity ratio (ηA/ηB) of the polyamide A to the polyester copolymer B is at least 5:1. It is also desirable that the polyamide film contains at most 1wt.% low-molecular weight components (oligomers and monomers) and has an overall degree of crystallization of less than 30%. |
