| 摘要 |
PURPOSE:To provide the transparent plastic film which has optically double refractiveness and high transparency as well as heat resistance and surface hardness and has the surface highly resistance to flawing and the process for producing said film by subjecting the film consisting of an amorphous arom. polymer to uniaxial stretching. CONSTITUTION:The amorphous arom. polymer in order to obtain the transparent film having the double refractiveness is exemplified by arom. polyester, arom. polysulfone, arom. polycarbonate, arom. polyether, etc. These polymers are used alone or in combination of >=2 kinds. The arom. polyester or arom. polycarbonate has high heat resistance and less thermal deformation and is, therefore, adequate. The films consisting of these polymers are obtd. by extrusion molding or casting from a doping liquid. The high double refractiveness is imparted to these films by uniaxially stretching the films or biaxially stretching the films by giving a difference to the degrees of biaxial stretching. |
