Patent GB-825535-A (GB)
Title: Process of dimerizing monounsaturated fatty acids
IPC: C07C57/13
Filed: 1955-11-21
Abstract: Dimers of C11-C22 mono unsaturated fatty acids are prepared, according to one method, by a process comprising heating an acid reactant consisting of one or more C11-C22 mono unsaturated fatty acids or a mixture thereof with one or more other fatty acids, excepting any mixture of fatty acids in which the amount by weight of mono unsaturated fatty acid is less than the amount of polyunsaturated fatty acid, to a temperature in the range of substantially 180-300 DEG  C. for a period of substantially 1-6 hours in the presence of substantially 1-20% by weight of crystalline clay mineral having a pH of 2-7 and substantially 1-5% by weight of water, each amount being based on the weight of acid reactant, and agitating the mixture of fatty acids, crystalline clay mineral and water during the treatment, the temperature, time and amounts of clay and water all being coordinated so that, following an initial increase to a maximum, the neutralization equivalent of the polymeric component of the reaction mixture is reduced to not more than 25 units higher than the saponification equivalent; preferably, the acid reactant is heated with about 2-6% of the clay having a pH of 3-5, and 1-5% of water at about 200-260 DEG  C. for 2-4 hours.  In another method, oleic acid dimers are prepared by heating a fatty acid feed-stock, of which at least 50% by weight comprises oleic acid, with substantially 2-6 parts by weight of crystalline clay mineral of pH 2-7 in the presence of substantially 2-4 parts by weight of water to 100 parts by weight of feed-stock at a temperature of substantially 215-240 DEG C. for a period of substantially 2-4 hours but sufficiently long to reduce the neutralization equivalent of the polymer component to 320 or below, agitating the mixture of feed-stock, clay and water during the heating, removing the water and then the clay from the acids after termination of the heating treatment and distilling the residue under reduced pressure to remove the monomeric acids therefrom. In general, the procedure followed is that described in Specification 825,534.  Examples are given illustrating the dimerization of commercial oleic and undecylenic acids, erucic acid, elaidic acid, olive oil foots acids and animal grease fatty acids of I.V. 63.ALSO:Dimers of C11-C22 monounsaturated fatty acids are prepared, according to one embodiment of the invention, by a process comprising heating an acid reactant consisting of one or more C11-C22 monounsaturated fatty acids or a mixture thereof with one or more other fatty acids excepting any mixture of fatty acids in which the amount by weight of monounsaturated fatty acid is less than the amount of polyunsaturated fatty acid, to a temperature in the range of substantially 180-300 DEG  C. for a period of substantially 1-6 hours in the presence of substantially 1-20% by weight of crystalline clay mineral having a pH of 2-7 and substantially 1-5% by weight of water, each amount being based on the weight of the acid reactant, and agitating the mixture of fatty acids, crystalline clay mineral and water during the treatment, the temperature, reaction time and amounts of clay and water all being coordinated so that following an initial increase to a maximum, the neutralization equivalent of the polymeric component of the reaction mixture is reduced to not more than 25 units higher than the saponification equivalent; preferably, the acid reactant is heated with about 2-6% of the clay of pH 3-5 and 1-5% of water at about 200-260 DEG  C. for 2-4 hours.  In another method, oleic acid dimers are prepared by heating a fatty acid feed-stock of which at least 50% by weight comprises oleic acid, with substantially 2-6 parts by weight of crystalline clay mineral having a pH of 2-7 in the presence of substantially 2-4 parts by weight of the acid feed-stock, at a temperature of substantially 215-240 DEG C. for a period of substantially 2-4 hours but sufficiently long to reduce the neutralization equivalent of the polymer component to 320 or below, agitating the feedstock, clay and water together during the heating, removing the water and then the clay from the acids after termination of the heating treatment and distilling the residue under reduced pressure to remove the monomeric acids therefrom.  In general, the procedure followed is that described in Specification 825,534.  Examples are given, illustrating the dimerization of commercial oleic acid, animal grease fatty acids of I.V. 63, commercial undecylenic acid, erucic acid, elaidic acid and olive oil foots acid.