| 摘要 |
1,160,255. Monostearyl fumaric acid derivatives. CHAS PFIZER & CO., Inc. 26 Oct., 1966 [18 Nov., 1965; 27 Sept., 1966], No. 48133/66. Heading C2C. [Also in Division A2] Finely divided monostearyl fumaric acid or the sodium, potassium, calcium or magnesium salt thereof, having a surface area of at least one square metre per gram and consisting of particles having an average spherical diameter up to 5 microns, may be obtained from the corresponding fumarate, consisting of particles substantially all of which are at least 5 microns in diameter and 95% of which are at least 10 microns in diameter, by conventional methods, for example by dry-milling or by recrystallizing from hot fats and oils or from aqueous media the corresponding macrocrystalline form. The dry-milling process, which is a preferred method for the preparation of microcrystalline monostearyl fumaric acid, may be effected by employing any conventional milling and classifying equipment, e.g. jet mills, ball mills or other impact mills, pin mills or micronizers. The process of recrystallization from a fat or oil, e.g. cottonseed, soybean, safflower or corn oils or low-melting solid shortenings, e.g. lard and hydrogenated vegetable shortenings, may be effected by dissolving the macrocrystalline form in the edible oil or liquid fat system at elevated temperature, e.g. 100-140‹ C., and rapidly cooling the solution with agitation. The aqueous recrystallization process may be effected (i) by solubilizing the macrocrystalline compound in the aqueous medium by heating to a temperature slightly below the boiling point of the medium and then rapidly lowering the temperature of the system to at least 70‹ C., or (ii) by a continuous process by slurrying the macrocrystalline fumerate in the aqueous medium, feeding the slurry through a heat exchanger, holding the slurry at the solubilization point and thereafter flashing off the water. |
