PURPOSE: To obtain a photochromic material composition which can be formed into a membrane or a molding in high productivity, is reduced in product cost and can give a product of a complicated shape, by kneading a dimerized photochromic material with a polymeric material at high temperature and forming the mixture into a membrane or a molding.
CONSTITUTION: A dimerized photochromic material is kneaded with a polymeric material at high temperature, and the mixture is formed into a membrane or a molding. Because the melting point and thermal decomposition temperature of the photochromic material are low, there has been a problem of low productivity because of impossibility of directly forming into a membrane by kneading it with a polymeric matrix material during membrane formation. The melting point and thermal decomposition temperature can be remarkably increased by dimerization, and therefore according to the above process, the membrane formation and molding can be performed at low cost, the thickness of a photochromic layer is increased to give improved weather resistance, and the molding of a product of a complicated shape is possible. As said photochromic material, a spirooxazine material can be used.
ITO HITOSHI
MAEDA SHUICHI
MITSUHASHI KAZUO
MITSUBISHI CHEM IND