Patent GB-735697-A (GB)
Title: Improvements in or relating to the treatment of fatty acids
IPC: C09F5/00
Filed: 1951-11-05
Abstract: Fatty acids having 13 to 25 carbon atoms in the molecule are heated with a keto fatty acid or a derivative thereof containing a keto group to bring about a reduction therebetween so as to reduce the free fatty acid content of the reaction mixture with the elimination of water.  The keto fatty acid derivative may be an oil containing a glyceride of a keto fatty acid having 13 to 25 carbon atoms in the molecule, e.g. oiticica oil, po-yoak oil and cacahuanache-nut oil, or it may be an oxidized oil in which carbonyl groups have been formed by oxidation.  The fatty acids may be those derived from tall oil or the soapstock fatty acids obtained in the refining of non-drying, semi-drying or drying oils such as rape-seed oil, soya-bean oil and linseed oil.  The heating is preferably carried out with the exclusion of air, e.g. in an inert atmosphere such as carbon dioxide, and at a temperature of 150-320 DEG  C.  An esterification catalyst which may be an alkaline catalyst or a finely divided metal such as zinc or tin may be present during the heating.  Specified alkaline catalysts are alkali metal and alkaline earth metal hydroxides, e.g. sodium or calcium hydroxide, or an alkali metal or alkaline earth metal soap.  A non-drying or slowly thickening oil or resin commonly used in the manufacture of varnishes, e.g. linseed oil, may be added to the reaction mixture.  Polyhydric alcohols may be added to the reaction mass whereby the remaining fatty acids are esterified. Examples are given in which oiticica oil is heated in the presence of various catalysts with (1) a tall oil distillate freed from solid resin acids; (2) a tall oil distillate low in resin acids; (3) a mixture of tall oil fatty acids and crude linseed oil, the product being a bodied varnish; (4) a mixture of corn oil fatty acids, glycerol being then added and esterification effected; (6) crude fatty acids obtained from the refining of linseed oil; (9) a mixture of crude fatty acids obtained from the refining of linseed oil, the product being a thick drying oil.  In other examples (5), (7) and (8) prepolymerized oiticica oil is heated with a technical fatty acid mixture obtained from the refining of rape seed oil, crude linseed oil fatty acids, and distilled soya bean fatty acids, respectively, the catalysts being zinc dust, caustic lime, and technical calcium linoleate respectively.ALSO:Fatty acids having 13 to 25 carbon atoms in the molecule are heated with a keto fatty acid or a derivative thereof containing a keto group to bring about a reaction therebetween so as to reduce the free fatty acid content of the reaction mixture with the elimination of water.  The keto fatty acid derivative may be an oil containing a glyceride of a keto fatty acid having 13 to 25 carbon atoms in the molecule, e.g. oiticica oil, po-yoak oil and cacahuanache-nut oil, or it may be an oxidized oil in which carbonyl groups have been formed by oxidation.  The fatty acids may be those derived from tall oil or the soap-stock fatty acids obtained in the refining of non-drying, semi-drying or drying oils such as rape-seed oil, soya-bean oil and linseed oil.  The heating is preferably carried out with the exclusion of air, e.g. in an inert atmosphere such as carbon dioxide, and at a temperature of 150-320 DEG  C.  An esterification catalyst, which may be an alkaline catalyst or a finely-divided metal such as zinc or tin, may be present during the heating.  Specified alkaline catalysts are alkali-metal and alkaline-earth metal hydroxides, e.g. sodium or calcium hydroxide, or an alkali-metal or alkaline-earth metal soap. A non-drying or slowly thickening oil or resin commonly used in the manufacture of varnishes, e.g. linseed oil, may be added to the reaction mixture.  Polyhydric alcohols may also be added to the reaction mass, whereby the remaining fatty acids are esterified. Examples are given in which oiticica oil is heated in the presence of various catalysts with (1) a tall oil distillate freed from solid resin acids; (2) a tall oil distillate low in resin acids; (3) a mixture of tall oil fatty acids and crude linseed oil, the product being a bodied varnish which, after the addition of drying agents such as lead naphthenate and diluents such as petroleum naphtha, dries to a varnish film in about 24 hours; (4) a mixture of corn oil fatty acids, glycerol being then added and esterification effected; (6) crude fatty acids obtained from the refining of linseed oil, the product being diluted with mineral spirits and lead/cobalt naphthenates being added as drying agents; (9) a mixture of crude fatty acids obtained from the refining of linseed oil, the product being a thick drying oil to which a lead drying agent is added.  In other examples: (5), (7), and (8) pre-polymerized oiticica oil is heated with a technical fatty acid mixture obtained from the refining of rape-seed oil, crude linseed oil fatty acids, and distilled soya bean fatty acids, respectively, the catalysts being zinc dust, caustic lime, and technical calcium linoleate respectively.