| 发明名称 | Method for purifying methacrylic acid | ||
| 摘要 | Provided is a crystallization method by which a highly-pure methacrylic acid crystal can be produced with high productivity. The method for purifying methacrylic acid according to the present disclosure involves using crude methacrylic acid having a maleic acid concentration of 2000 ppm by mass or less and an acrylic acid concentration of 2000 ppm by mass or less and setting the slurry temperature to −10 to 10° C. in order to crystallize methacrylic acid. A suspension-type jacket-cooling-system crystallization vessel is used as the crystallization apparatus, and an absolute value of the difference between a crystallization temperature and a temperature of a cooling medium in the jacket is preferably 15° C. or less. | ||
| 申请公布号 | US9238610(B2) | 申请公布日期 | 2016.01.19 |
| 申请号 | US201214366673 | 申请日期 | 2012.12.26 |
| 申请人 | MITSUBISHI RAYON CO., LTD. | 发明人 | Hino Tomomichi;Kato Shinpei;Sonobe Hideyuki;Hoshino Manabu |
| 分类号 | C07C51/43;C07C51/44;C07C51/48;C07B63/00 | 主分类号 | C07C51/43 |
| 代理机构 | Jianq Chyun IP Office | 代理人 | Jianq Chyun IP Office |
| 主权项 | 1. A method for purifying methacrylic acid, comprising: crystallizing methacrylic acid, using crude methacrylic acid as a raw material having a maleic acid concentration of no greater than 2000 ppm by mass and an acrylic acid concentration of no greater than 180 ppm by mass, and setting a slurry temperature at −10˜10° C., wherein a suspension-type jacked-cooled crystallization vessel is used as a crystallization device, and an absolute value of the difference between a crystal deposition temperature and a temperature of a cooling medium in the jacket is set at 15° C. or lower. | ||
| 地址 | Tokyo JP | ||