| abstract |
A cyclic carbodiimide compound represented by formulas (O-1) or (O-2) can be used for producing a polyester film that does not contain isocyanates with a small molecular weight and that has excellent thickness uniformity without any thickening, and is capable of suppressing thickening when producing a film and suppressing generation of isocyanate gas. (R 1 , R 5 , R 11 , R 15 , R 21 and R 25 are an alkyl group, an aryl group or an alkoxy group; R 2 -R 4 , R 6 -R 8 , R 12 -R 14 , R 16 -R 18 , R 22 -R 24 and R 26 -R 28 are a hydrogen atom, an alkyl group, an aryl group or an alkoxy group; R 1 -R 8 can be linked together to form a cycle; R 11 -R 28 can be linked together to form a cycle; X 1 , X 2 , X 11 , X 12 , X 21 and X 22 are a single bond, and -O-, -CO-, -S-, -SO 2 -, -NH- or -CH 2 -; L 1 is a divalent linking group; and L 2 is a tetravalent linking group.) |