Patent GB-630610-A (GB)
Title: Improvements in or relating to acylated esters of hydroxy-substituted 18 carbon atom aliphatic monocarboxylic acids and process of preparing same
IPC: C11C3/04
Filed: 1946-08-01
Abstract: Vinyl resins are plasticized by the ester products obtained by acylating an ester of a hydroxy-substituted 18 carbon atom aliphatic monocarboxylic acid with a fatty acid anhydride containing from 4 to 8 carbon atoms at a temperature of 175 DEG  to 260 DEG  C. and for not more than 20 minutes (see Group IV (b)).  In examples, the acetylated castor oil products obtained by reacting castor oil with acetic anhydride at 190 DEG  C. for 7 minutes and at 197 DEG  C. for 6 minutes respectively, are employed as plasticizers in compositions containing polyvinyl chloride, clay, basic lead carbonate, and dioctyl phthalate, either of the acetylated products being present. The ingredients are mixed at 300 DEG  F. and then moulded into discs. The compositions have a high electrical resistivity and may be used for electrical insulation.ALSO:An ester of a hydroxy substituted 18 carbon atom aliphatic monocarboxylic acid is acylated with a fatty acid anhydride containing from 4 to 8 carbon atoms by maintaining a mixture thereof at a temperature of from 175 DEG  to 260 DEG  C. for a period of time sufficient for substantial completion of the reaction and not more than 20 minutes, and separating the resulting acylated ester from any unreacted reagents and from the fatty acid produced.  A catalyst, e.g. sulphuric or hydrochloric acid may be used. Specified ester starting materials are methyl-, ethyl-, butyl-, phenyl-, tolyl-, benzyl- and cyclohexyl ricinoleates, castor oil, hydrogenated castor oil, methyl 11-hydroxy stearate, ethyl 11-hydroxystearate and isoamyl 11-hydroxystearate.  Specified acid anhydrides are acetic, propionic, butyric and isobutyric anhydrides. Inert diluents or solvents may be used and the reactants may be preheated and then introduced separately into the reaction chamber, or the cool reactants may be premixed or introduced separately into the reaction chamber and the heating accomplished in the chamber. The reactants may be used in the liquid phase or the anhydride may be in the vapour phase.  The reaction may be conducted batchwise, but is best carried out continuously, preferably employing a counter current flow of preheated reactants.  In examples: (1) castor oil heated to about 195 DEG  C. in a heat exchanger is introduced to the top of a reaction chamber consisting of a heat insulated vertical glass column packed with Berl Saddles.  Acetic anhydride vapour at 140 DEG  to 160 DEG  C. is continuously introduced near the bottom of the column, about 70 per cent excess by weight of the anhydride over the amount theoretically required to react completely with all the castor oil being used.  A mixture of acetic anhydride and acetic acid is continuously removed from the top of the column and the acetylated castor oil and a small amount of acetic anhydride and acetic acid are continuously withdrawn at the bottom.  The temperature at the centre of the column is about 190 DEG  C. and the time for the passage of any given portion of castor oil through the column is about 7 minutes; (2) the reaction is effected as in (1) except that the temperature at the centre of the column is 197 DEG  C., the castor oil being preheated to 223 DEG  C., and the passage time is 6 minutes.  In each example the product withdrawn from the reaction chamber is cooled rapidly to below 100 DEG  C. and then heated and treated with superheated steam under reduced pressure to remove the acetic acid and anhydride.  The ester products are useful as plasticisers for vinyl resins, the plasticised compositions are used for electrical insulation.