Patent GB-303560-A (GB)
Title: Softening agent for coating compositions containing nitro-cellulose or the like, and process of preparing the same
IPC: D06N3/02
Filed: 1927-10-06
Abstract: 303,560. Marks, E. C. R., (Alox Chemical Corporation). Oct. 6, 1927. Carboxylic acids ; formic acid ; ketones ; aldehydes. -Carboxylic acids suitable for use as softening agents in cellulose, nitrate coating- compositions are made by oxidizing by air or other gas containing free oxygen, a petroleum hydrocarbon mixture in liquid phase at suitable temperature (100-160‹ C. and pressure (100- 350 lb.), saponifying the petroleum-soluble, acids produced, and decomposing the soaps with acids. The oxidation is effected in a cylinder 1, which may be lined with non-corrodible material such as aluminium, provided with a coil 3 for heating or cooling and if desired with a jacket or other means for the same purpose. The oil is supplied from a tank 4 by a pipe 7 and compressed air from a compressor 6 by a pipe 4, gaseous products being withdrawn by a pipe 9 and liquid products by a pipe 8 discharging into a separating tank 12. The oil which may be Pennsylvania. oil of 45‹ Be., with a catalyst such as a compound of manganese, copper, or iron, (manganese oleate being mentioned) or with some of the ketonic products of the reaction, is charged into the cylinder 1 and the oxidation is started. Volatile acids, chiefly formic acid, and ketones escape with the gaseous products and are condensed. The first products. of oxidation are formic acid and ketones or aldehydes of high molecular weight, which are then oxidized to carboxylic acids soluble in petroleum and having molecular weights about 50 per cent more than would be expected. Further oxidation converts these into hydroxy acids insoluble in petroleum and of about the same molecular weight as would be expected. The process is conducted so as to produce the petroleum-soluble acids, avoiding the production of the hydroxy-acids. For this reason it is preferred to start with an oil free from wax, and the oxidation should be carried to about 20 per cent. The oxidized product is washed with water in the tank 12 to remove water soluble bodies, and is treated with caustic soda from a pipe 16 to produce soaps, water from a pipe 15 being added if necessary to obtain a clear separation of the soap solution from unsaponined oil. The oil is taken by pipe 13<1> to the supply tank 14 and the soaps are discharged to a tank 17 and decomposed by sulphuric acid from a pipe 18, using a slight excess of acid. The separated acids, or an oily nature, are led to a still 20 for the removal of volatile substances at about 150‹ C. and 10-20 mm. in a stream of superheated steam; air &c., and finally a rapid current of steam is blown through. leaving a fatty acid product of 1.011-1.015 density, which may be esterified by the usual methods to form a product very similar to castor oil. The oxidation process may be effected continuously. In a discussion of the course of the oxidation it is suggested that the high molecular weight of the carboxylic acids may be due to the union of one acid molecule with an alcoholic group at the other end of another acid molecule, resulting in an ester-acid of high molecular weight, and that lactones may be formed from the molecules having a carboxylic group at one end and a secondary alcohol group adjoining the other end. It, is stated that by partial precipitation from an acid having an average molecular weight of 360, acids have been obtained with molecular weights as high as 800 and so low as 100, particularly when hydroxy-acids have been formed.