| abstract |
PURPOSE: To provide a film which can convert light in a short wavelength range into one having a longer wavelength with good weather resistance and is useful for agricultural use for controlling the growth of plants, by incorporating a specified perylene pigment into a transparent plastic. n CONSTITUTION: A perylene pigment of the formula (wherein Y is oxygen, -NR ; R is H, a 1W5C lower alkyl or phenyl group which may be substituted with lower alkyl, lower alkoxy or halogen ; n is 1W8) is incorporated into a transparent plastic. As said transparent plastic, a plymer having a solubility parameter of 9 or higher is preferred. When the solubility parameter of the polymer is lower than 9, the solubility of the pigment in the polymer is very low, fluorescence can not be observed and film becomes easily opaque. Thus, such solubility parameter is not preferred. Since the purpose of the use of the pigment is different from mere coloration, the pigment is used in an amount of 0.001W3.0wt%. n COPYRIGHT: (C)1982,JPO&Japio |