Abstract: A methacrylic resin composition comprising 100 parts by mass of a methacrylic resin having an amount of a terminal double bond of less than 0.012% by mole and an amount of a bonded sulfur atom of preferably less than 0.25% by mole; 5×10?6 to 9×10?3 part by mass of a metal element having an atomic number of not more than 20 (preferably lithium element and aluminum element); and 0.025 to 0.50 part by mass of a hindered phenol antioxidant such as 2,6-bis(1,1-dimethylethyl)-4-methylphenol, wherein the methacrylic resin composition, when being exposed to a nitrogen gas atmosphere at 290° C. for 15 minutes, has a thermogravimetric retention of not less than 98% by mass.

Abstract: A methacrylic resin composition comprising 100 parts by mass of a methacrylic resin having an amount of a terminal double bond of less than 0.012% by mole and an amount of a bonded sulfur atom of preferably less than 0.25% by mole; 5×10?6 to 9×10?3 part by mass of a metal element having an atomic number of not more than 20 (preferably lithium element and aluminum element); and 0.025 to 0.50 part by mass of a hindered phenol antioxidant such as 2,6-bis(1,1-dimethylethyl)-4-methylphenol, wherein the methacrylic resin composition, when being exposed to a nitrogen gas atmosphere at 290° C. for 15 minutes, has a thermogravimetric retention of not less than 98% by mass.

Abstract: Provided are a break-resistant copolymer having high transparency and heat resistance and also having a high tensile strain at break, and a molded article. A copolymer contains 80% by mass to 98% by mass of structural units derived from a methacrylic ester monomer and 2% to 10% by mass of ester structural units derived from a cyclic ketene acetal monomer. The copolymer has a weight average molecular weight of 80,000 or more and a molecular weight distribution of 1.75 to 3.80.

Abstract: A methacrylate resin composition containing a methacrylate resin and a phenoxy resin and a film consisting of the same, each having high transparency, small phase differences in a thickness direction, low heat shrinkage rate, high strength and good adhesion properties are provided. The methacrylate resin composition contains a methacrylate resin with a triad syndiotacticity (rr) of equal to or more than 58% and a phenoxy resin, and the content of the phenoxy resin per 100 parts by mass of the methacrylate resin is in a range of 0.1 to 8 parts by mass, and the total content of the methacrylate resin and phenoxy resin is 80 mass % or more.

Abstract: Provided are a break-resistant copolymer having high transparency and heat resistance and also having a high tensile strain at break, and a molded article. A copolymer contains 80% by mass to 98% by mass of structural units derived from a methacrylic ester monomer and 2% to 10% by mass of ester structural units derived from a cyclic ketene acetal monomer. The copolymer has a weight average molecular weight of 80,000 or more and a molecular weight distribution of 1.75 to 3.80.