GB532054A - Improvements in or relating to the manufacture of unsaturated esters - Google Patents

Abstract

532,054. Methacrylic esters. BRITISH CELANESE, Ltd. Aug. 15, 1939, No. 23519. Convention date, Aug. 16, 1938. [Class 2 (iii)] Methallyl methacrylate is made by condensing methacrolein in the presence of an aluminium alcoholate. Aluminium ethoxide may be used as the condensing agent, but aluminium methallyloxide is preferably employed. The latter may be made by activating aluminium by treatment with absolute alcohol in the presence of mercuric chloride and iodine, and treating the activated aluminium with methallyl alcohol. In an example of the preparation of methallyl methacrylate, equal quantities of methacrolein and aluminium methallyloxide are heated in ethyl acetate. The methallyl ester may be converted to other esters by refluxing with excess of the alcohol corresponding to the desired ester in the presence of an acid catalyst, e.g. phosphoric acid. The alcohols may be monohydric, e.g. methyl, ethyl, propyl, isopropyl or butyl alcohols, or di- or trihydric, e.g. a glycol or glycerol. An example of the preparation of ethyl methacrylate is given. The products may be polymerized with the aid of light, heat, ultra-violet rays, or a catalyst such as benzoyl peroxide, to form synthetic resins which may be formed into sheets, for use as a substitute for glass, filaments, rods &c.