| 摘要 |
An acrylic polymer composition comprises (I) a copolymer of methyl methacrylate and isobornyl acrylate and/or isobornyl methacrylate and (II) a flame-resistant polymeric phosphorus compound, the amount of phosphorus compound being 5 to 25% by weight of the total composition and the amount and nature of the copolymer being such that the methyl methacrylate units therein constitute at least 50%, and the isobornyl acrylate and/or methacrylate units therein constitute 5 to 30%, by weight of the total composition, with the proviso that some of the methyl methacrylate units may optionally be replaced by units of an acrylic modifier as long as no more than 5% by weight, based on the total weight of the composition, of units of acrylic modifier are present. The compositions may be obtained by polymerizing the monomers in the presence of the phosphorus compound. Suitable acrylic modifiers are, e.g., ethyl acrylate, methacrylic acid and glycidyl methacrylate. In the examples are used: a commercially available phosphonate containing chlorine, methacrylic acid, a chlorine and bromine containing phosphonate, phosphonate polymers prepared from (1) ethylene chlorophosphonite, methylene dichloride and acetone, (2) ethylene chlorophosphite, methyl hexyl ketone and ethyl alcohol, (3) ethylene chlorophosphite and diethyl ketone, (4) 1,2-propylene chlorophosphite, methylene dichloride, acetone and water, (5) acetone, 1,3-butylene chlorophosphite, and methylene dichloride, (6) ethyl acetoacetate, ethanol and ethylene chlorophosphite, (7) cyclohexanone, ethylene chlorophosphite and methylene dichloride. The addition polymerization catalyst used was acetyl peroxide in dimethyl phthalate and the compositions were polymerized between glass plates. In a comparative example t-butyl methacrylate is used. |
