Improvements in the manufacture of synthetic camphor
Реферат: Esters are prepared from turpentine and an acid, such as formic, acetic, butyric, sebacic, benzoic, salicylic, but preferably oxalic acid with the acid of a solvent, consisting of a chlorinated or brominated hydrocarbon suich as methylene p chloride, chloroform, carbon tetrachloride, ethylene chloride or bromide, or tetrachlorethane, in the absence of inorganic chlorides. The solvents are stated to act as catalysts. The solvent, turpentine, and anhydrous oxalic acid may be heated together at 115-140 DEG C., sufficient of the solvent being used to bring the boiling-point of the mixture to the required temperature. The product is mainly the neutral bornyl oxalate, from which excess of turpentine and the solvent may be distilled first in vacuum and then in steam, and may be re-used. The ester is saponified by soda, and the alcohol oxidized to camphor by known methods. With sebacic acid, an acid ester is obtained. Specifications 26785/03, 20526/06, 14408/08, and 158,533 are referred to. The Specification as open to inspection under Sect. 91 (3) (a) refers to Specifications 14754/00 and 2129/02; it mentions trichlorethylene, benzene, and acetone as solvents. This subject-matter does not appear in the Specification as accepted.
Improvements in the process of manufacture of hexamethylene diisocyanate
Номер патента: GB833467A. Автор: . Владелец: SOLVAY SA. Дата публикации: 1960-04-27.