FLUORORESIN FILM HAVING EXCELLENT TRANSPARENCY

摘要

The present invention aims to provide an ETFE film having excellent transparency and heat resistance and cost efficiency. The present invention relates to a film including a copolymer containing an ethylene unit, a tetrafluoroethylene unit, and a (fluoroalkyl)ethylene unit represented by Formula (1):;CH2═CX—Rf  (1);wherein X represents H or F, and Rf represents a fluoroalkyl group having 2 or more carbon atoms, the copolymer containing the (fluoroalkyl)ethylene unit in an amount of 0.8 to 2.5 mol % relative to the amount of all the monomer units and containing the ethylene unit and the tetrafluoroethylene unit at a molar ratio of 30.0/70.0 to 50.0/50.0, the film having a crystallinity of 68% or less, the crystallinity being calculated on the basis of a diffraction intensity curve of the film resulting from X-ray diffraction measurement.

主权项

1. A film comprising a copolymer, the copolymer containing an ethylene unit, a tetrafluoroethylene unit, and a (fluoroalkyl)ethylene unit represented by Formula (1):
CH2=CX—Rf  (1) wherein X represents H or F, and Rf represents a fluoroalkyl group having 2 or more carbon atoms,
the copolymer containing the (fluoroalkyl)ethylene unit in an amount of 0.8 to 2.5 mol % relative to the amount of all the monomer units and containing the ethylene unit and the tetrafluoroethylene unit at a molar ratio of 30.0/70.0 to 50.0/50.0,the film having a crystallinity of 68% or less, the crystallinity being calculated by the following equation on the basis of a diffraction intensity curve of the film resulting from X-ray diffraction measurement:
Crystallinity (%)=(S19+S20)/(S17+S19+S20)×100 wherein S20 represents a peak area around 2θ=20°, S17 represents a peak area around 2θ=17°, and S19 represents a peak area around 2θ=19°.