| 摘要 |
<p>Vinyl esters are prepared by a process comprising effecting an ester-interchange between a vinyl ester of a low molecular weight carboxylic acid having 1 to 4 carbon atoms and a carboxylic acid containing 3 to 26 carbon atoms of higher molecular weight by reacting the ester and acid together in the presence of a mercury salt of an aromatic sulphonic acid; preferably, there is used a mercuric salt which, if desired, may be formed in situ from mercuric acetate and the sulphonic acid. The catalyst may be added in stages and the original vinyl ester is preferably used in excess. Reaction may be effected at below room temperature up to the boiling point of the reaction mixture but preferably below 60 DEG C. Use of the lower temperatures avoids formation of ethylidene diester-type by-products. Their formation is also reduced by terminating the reaction at the optimum point, for example, by addition of sodium acetate. Polymerization inhibitors, e.g. copper acetate, may be present. The resulting esters may be homoor polymerized. Examples describe ester-interchange between vinyl acetate and capric, caprylic, benzoic, lauric, myristic, adipic, sebacic, behenic, stearic or pyro mellitic acid or distilled linseed oil or dehydrated castor oil fatty acids, the catalyst being mercuric toluene sulphonate or naphthalene-2-sulphonate which sometimes is formed in situ. U.S.A. Specification 2,299,862 is referred to.</p> |
