Patent GB-515172-A (GB)
Title: Manufacture of driers for varnishes, lacquers, paints and plastic masses
IPC: C09F9/00
Filed: 1938-05-26
Abstract: 515,172. Phthalic ester-acid driers: I. G. FARBENINDUSTRIE AKT.-GES. May 26, 1938, No. 15735. Convention date, May 26, 1937. [Classes 1 (iii) and 95] [Also in Group IV] Driers comprise the polyvalent metal salts of mono-ester acids of phthalic acid, wherein the mono-ester acid is obtained by condensing phthalic anhydride with at least one monohydric aliphate, aromatic, or hydroaromatic alcohol, at 95-105‹C. and preferably at 95-97‹C., the alcohol or alcohols being present in a small excess, say 1.05-1.10 mols. alcohol per mol. of anhydride, whereby formation of free phthalic acid or of diesters is avoided. The metal salts obtained are therefore free from phthalates which are insoluble or sparingly soluble in fatty oils and volatile solvents. Salts of cobalt, manganese, lead, zinc, aluminium, calcium, copper, iron, mercury, bismuth, tin, cadmium, chromium, cerium, and vanadium are referred to, and they may be obtained either by the "precipitating" process, or by the "melting" process preferably under reduced pressure, and with the addition of a small quantity of a free iso-carboxylic acid, naphthenic acid, fatty acid; or resinic acid. The isobutyl oil boiling between 100 and 180‹C. obtained as a byproduct in the manufacture of methanol by catalytic reduction of carbon monoxide may be used to form the ester-acid, and for production of the metal salt the ester-acid may be used in admixture with a carboxylic acid or acids obtained by the alkaline oxidation at a raised temperature and if necessary under pressure of at least one primary alcohol, and particularly of the mixed alcohols of high molecular weight contained in the said isobutyl oil, and/or with a naphthenic acid, fatty acid, resinic acid, benzoic acid or derivative thereof, or a wool fat acid. In one. example, isohexyl alcohol is condensed with phthalic anhydride, the esteracid converted to its sodium salt, a small quantity of naphthenic acid added, and the lead salt of the ester-acid precipitated by adding lead nitrate. In a second example a mixture of isobutyl and isoheptyl alcohols is used, and the cobalt salt of the ester-acid precipitated in the presence of a small quantity of iso-carboxylic acid. In a third example, the ester-acid obtained from the mixed alcohols of the "isobutyl oil" above referred to is mixed with the isocarboxylic acids obtained by oxidation of the oil, and a mixed lead and manganese salt precipitated in the presence of a small quantity of linseed oil fatty acid. In a fourth example,' the ester-acid of the preceding example is heated to 100‹C. and cobaltous hydroxide added gradually with stirring and increase of temperature to 120‹C. under reduced pressure. In a fifth example, a mixture of the isoamyl esteracid and "isocarboxylic acid" is heated to 120‹C. and manganese acetate gradually added with stirring and increase of temperature to 140-150‹C. In a final example, a mixture of the isobutyl oil ester-acid, isocarboxylic acid, and naphthenic acid is heated to 100‹C. and zinc oxide and cobaltous hydroxide gradually'added with stirring and increase of temperature to 140‹C. under reduced pressure. The products of the process may be mixed with other driers such as naphthenates, linoleates, resinates, benzoates, or wool fat driers. Specification 513,222 is referred to.