| 摘要 |
<p>1,145,477. Ethylene glycol purification. COLUMBIAN CARBON CO. 11 July, 1966 [30 Aug., 1965], No. 31094/66. Heading C2C. Ethylene glycol having a trace iron content is contacted with a cation exchange resin in the acid form to reduce the iron content and give a product having substantially no increased acidity. The treatment is preferably applied to substantially anhydrous ethylene glycol containing up to 2 p.p.m. of iron and up to 100 p.p.m. titratable acids, calculated as acetic acid, and gives products containing, e.g. 0À15 p.p.m. of iron and may reduce the acidity to 50 p.p.m. Suitable resins are those of the sulphonated phenolformaldehyde, sulphonated polystyrene and sulphonated polystyrene carboxylic acid types. The resin is preferably dried before use by contact with anhydrous ethylene glycol.</p> |
