| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of drop out caused by coarse projections and improve the output characteristics by forming a film from an aromatic polyamide containing inorganic particles wherein the proportions of inorganic particles observed on the surface of the film and having various degrees of agglomeration are specified. SOLUTION: A film is formed from a mixture of an aromatic polyamide containing at leas 50 mol% repeating units of formula I or II with 0.01-3 wt.% inorganic particles having a mean secondary particle diameter of 10-500 nm. The film is heat treated and then stretched to give an aromatic polyamide film wherein the number An of inorganic particles with a degree of agglomeration n among those contained in the film and observed on the surface satisfies the relation of formula III, wherein the number of surface projections due to inorganic particles at least on one side is 10,000-5,000,000/mm2, preferably 20,000-3,000,000/mm2, and which has a thickness of 0.5-30μm, preferably 1-20μm, and a Young's modulus in tension in one direction of at least 800 kg/mm2. In the formula, Ar1, Ar2 and Ar3 are each a group of any one of formulas IV to VIII; X and Y each -O-, -CH2 or the like; and 1<=n<=3. |
