GB825534A - Process of making polymeric acids - Google Patents

Abstract

Polymerized fatty acids are prepared from polyunsaturated fatty acids occurring naturally in oils or fats by a process comprising heating an acid reactant consisting of one or more such polyunsaturated 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 equal to or greater than the amount of polyunsaturated fatty acid, in the presence of substantially 1-20% by weight of a crystalline clay mineral of pH 2-7 and substantially 1-5% by weight of water, each percentage being based on the weight of acid reactant, the reaction being effected at such a temperature in the range of substantially 180-260 DEG C. and for such a time that, following an initial increase to a maximum, the neutralization equivalent of the polymeric component of the reaction mixture is reduced to no more than 25 units higher than its saponification equivalent. Suitably, 100 parts by weight of a fatty acid mixture containing unsaturated acids consisting predominantly by weight of polyunsaturated fatty acids are heated with 2-6 parts by weight of the clay and 1-5 parts by weight of water at 215-260 DEG C. for a period of 2-5 hours, the exact time being such that the polymeric component in the produce has an N.E. between 10 and 25 units higher than its S.E. Fatty acid reactants specified are linoleic acid, linolenic acid, mixtures of these two acids, and the acids of linseed, soybean, cottonseed, safflower, corn and tall oils. Suitable clays include montmorillonite, kaolinite, hectorite, sepialite, halloysite, attapulgite, fuller's earth and "Filtrol" (Registered Trade Mark). The process is preferably effected by heating the acids, clay and water in a sealed pressure vessel with agitation; after the required drop in N.E. has occurred, the vessel is cooled and the reaction mixture is filtered to remove the catalyst and then distilled under reduced pressure to remove non-polymerized acids. Alternatively, a reactor provided with a reflux condenser to return vaporized water may be used. Specification 825,535 is referred to.ALSO:Polycarboxylic acids are prepared by the polymerization of polyunsaturated fatty acids occurring naturally in oils or fats by heating an acid reactant consisting of one or more such polyunsaturated 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 equal to or greater than the amount of polyunsaturated fatty acid, in the presence of substantially 1-20% by weight of a crystalline clay mineral of pH 2-7 and substantially 1-5% by weight of water, each being based on the weight of acid reactant, the reaction being effected at such a temperature in the range of substantially 180-260 DEG C. and for such a time that, following an initial increase to a maximum, the neutralization equivalent of the polymeric component of the reaction mixture is reduced to no more than 25 units higher than its saponification equivalent. In an embodiment, 100 parts by weight of a fatty acid mixture containing unsaturated acids consisting predominently by weight of the polyunsaturated fatty acids are heated with 2-6 parts by weight of the crystalline clay mineral and 1-5 parts by weight of water at 215-260 DEG C. for a period of 2-5 hours, the exact time being such that the polymeric component in the product has an N.E. between 10 and 25 units higher than its S.E. Fatty acid reactants specified are linoleic acid, linolenic acid, mixtures of these two acids, and the fatty acids of linseed, soybean, cottonseed, safflower, corn and tall oils. Suitable clays include montmorillonite, kaolinite, hectorite, sepialite, halloysite, attapulgite, fuller's earth and "Filtrol" (Registered Trade Mark). The process is preferably effected by heating the acids, clay and water in a sealed pressure vessel with agitation; after the appropriate drop in N.E. has occurred, the vessel is cooled, the reaction mixture is filtered to remove the clay and then distilled under reduced pressure to remove non-polymerized acid. Alternatively, a reactor provided with a reflux condenser to return vaporized water may be used. The polymerized acids may be used as corrosion inhibitors in gasoline, as components in poly-alkyd resins and in the manufacture of aluminium lubricating greases. In typical examples: (1) soybean oil acids (100 parts) are heated with "Filtrol" (4 parts) and water (2 parts) in an autoclave at 230 DEG C. for 4 hours and the products are worked up as above to recover dimeric acids having an N.E.=304 and a S.E.=286; (3) tall oil fatty acids (100 parts), "Filtrol" (2 parts) and water (4 parts) are similarly heated at 260 DEG C. for 2 hours yielding a polymeric acid residue on working up having an N.E.=309 and a S.E.=293; a much lower yield results when 10 parts of water are used; (6) distilled safflower fatty acids are heated with 4% of "Filtrol" and 2% of water at 230 DEG C. in an autoclave for 4 hours yielding polymeric acids having an N.E.=288 and a S.E.=279. Specification 825,535 is referred to.