| abstract |
(57) [Summary] [Structure] (A) A copolymer comprising a monomer mainly containing alkyl methacrylate and a copolymerizable unsaturated carboxylic acid or a salt thereof, and (B) an organic carboxylic acid and / or Or its neodymium salt, with a neodymium content of 0.3 In the transparent resin of 20 to 20% by weight, acrylic acid, methacrylic acid and their salt units in the copolymer and the organic carboxylic acid and its salt relative to the total number of carboxyl groups of the organic carboxylic acid and its salt The number of carboxyl groups possessed occupies the ratio x, the ratio of the carboxyl groups forming a salt by neutralizing neodymium among all the carboxyl groups is y, and x and y satisfy a specific formula. Neodymium-containing transparent resin and method for producing the same. [Effect] Even though it is transparent, it can selectively absorb light of wavelengths other than the three primary colors, so that it can be used as a photon resin material for the front plate of a color cathode ray tube or the like to prevent deterioration of image contrast. |