| 摘要 |
PURPOSE:To obtain an optical material having heat resistance, moisture resistance, chemical resistance and incombustibility with which light from UV rays to near infrared rays can be transmitted with extremely low loss by using a fluorine polymer substantially containing no C-H bonds. CONSTITUTION:This material consists of a noncrystalline fluorine-contg. polymer (a) which substantially does not contain C-H bonds and a material (b) having >=0.01 difference of refractive index from the refractive index of the fluorine- contg. polymer (a). The material (b) is distributed to give a gradient of density in a specified direction in the fluorine-contg. polymer (a). The noncrystalline fluorine-contg. polymer has excellent transparency since scattering due to crystallinity is not caused. As for the fluorine-contg. polymer (a), any noncrystalline fluorine-contg. polymer may be used as far as it does not contain C-H bonds, and especially, a fluorine-contg. polymer having a cyclic structure in the main chain is preferable. As for the material (b), a low mol.wt. compd., oligomer or polymer containing aromatic rings such as benzene ring, halogen atoms such as chlorine, bromine and iodine, and coupling groups such as ether bonds are preferably used. |
