| 摘要 |
1,173,118. Esterification of methacrylic acid. ROHM & HAAS G.m.b.H. 4 July, 1968 [11 July, 1967], No. 31947/68. Heading C2C. Esters of methacrylic acid e.g. methyl, ethyl and n-butyl methacylates are prepared by introducing methacrylic acid and an aliphatic alcohol in a equimolar ratio into a mixture initially comprising methacrylic acid and sulphuric acid and/or sulphonic acid in a propertion of 8 to 30% by weight; calculated as SO 3 content based on the amount of methacrylic acid initially present in said mixture, at a temperature of 70 to 170‹ C. The rate of introduction of the methacrylic acid and the alcohol into the mixture is not more than the rate of formation of the ester of methacrylic acid. The amount of methacrylic acid initially present in the mixture is 50 to 200% by weight of the amount of methacrylic acid introduced per hour into the mixture. |
