Patent GB-1045684-A (GB)
Title: Rust preventing primer compositions
IPC: C07F9/38
Filed: 1963-05-13
Abstract: Salts (which may be soluble or insoluble) capable of binding ferric ions are obtained from bi- or poly-functional organic nitrogen bases with mono- or poly-functional phosphonic acids, phosphonocarboxylic acids, oxyphosphonic acids and phosphonic or phosphonocarboxylic acids carrying hydroxyl and/or amino groups in a  and/or b  position with respect to the acid groups.  The acid used must be capable of forming complex metal salts. Mixtures of the acids may be used and 1, 3-diketo compounds may be added. The basic components may be benzidine or benzidinebiguanidine.  a  - Hydroxy - octadecyl - phosphonic acid is prepared by distilling n-butylchloride from a mixture of stearic acid chloride and tributylphosphite and refluxing the oily residue with sodium hydroxide in aqueous alcohol.  The solution is treated with water, butanol and sodium and acidified with hydrochloric acid. The butanol layer is separated and butanol distilled off to give the oily acid.  An amine salt of the acid mixed with another salt is prepared by dissolving the acid in aqueous sodium hydroxide and adding benzidine hydrochloride and potassium hexacyanoferrate. The precipitated salt is washed, dried and pulverized.  m - Phenylene - diketo - phosphonic acid is prepared by heating isophthalic acid dichloride with tributyl phosphite and distilling off butyl chloride.  The residue is refluxed with sodium hydroxide in aqueous alcohol.  Salts are formed by adding to an aqueous solution of the acid benzidine hydrochloride benzidine biguanidine and ammonia.  The salts mixture is precipitated by cooling, and washed, dried and pulverized.  Salts mixtures are also formed from m-phenylene-diketo-phosphonic acid and potassium hexacyanoferrate with benzidine hydrochloride, and from m-phenylene-diketo-phosphonic acid, the Na salt of methylene disalicylic acid, sodium tartrate, sodium saccharate (salt of tetrahydroxy adipic acid) and potassium hexacyanoferrate with benzidine hydrochloride.  The salts may be precipitated on a carrier, e.g. kieselguhr, and are useful in rust inhibiting paints (see Division C3).ALSO:A rust preventing primer composition comprises, as a rust inhibitor an insoluble or sparingly soluble salt of a bi- or a polyvalent organic nitrogen base with an acid capable of forming complex compounds with iron ions and as binder a soluble film-forming salt of a bi- or polyvalent organic nitrogen base with an acid capable of forming a complex compound with iron ions. The composition may also contain as a binder nitrocellulose, cellulose acetate or a polymer of an ester or an acetal of vinyl alcohol. The acid component or acid radical of the salt may be a mono- or a polyfunctional phosphonic acid, a phosphono-carboxylic acid, an oxophosphonic acid or a phosphonocarboxylic acid carrying hydroxyl and/or amino groups in alpha and/or beta position to one of the acid groups.  It may be a mono- or a polyfunctional aliphatic or aromatic amino carboxylic acid or hydroxy carboxylic acid carrying at least one amino or hydroxyl group in alpha- or beta-position to the carboxyl group.  It may be a hexacyanoferric acid, chromic acid, manganic acid, tungstic acid, or molybdic acid. 1,3-diketo-compounds may be used in conjunction with the acid component. The basic component of the salt may be benzidine, a benzidine-biguanidine or a high molecular weight condensation product of biguanidine and formaldehyde.  The basic component of a salt used as binder may be an acid amide carrying basic nitrogen substituents. The substituted acid amide may be an acid amide of a mono-, poly-, hydroxy- or aminocarboxylic acid, phosphonic acid, phosphonocarboxylic acid, hydroxy-, amino-, or ketophosphonic acid and/or a high molecular weight condensation or co-condensation product thereof with a primary and/or a secondary mono- or polyamine, a biguanidine or an alkylated phenol or a 1,3-diketo-compound having alkyl radicals with at least 8 carbon atoms, as obtained by condensation with formaldehyde. The rust-preventing agent and the binder may be dispersed in an aqueous medium with the aid of a known dispersing agent.  The rust preventing agent may be supported on a carrier material.  It may be mixed with sparingly soluble barium salts and/or with zinc dust. There may be present a reducing agent forming a sparingly soluble salt with the basic component of the rust-preventing agent.  Said reducing agent may be a compound of phosphorous acid or hypophosphorous acid.  In an example, a rust-preventing salt, prepared by reacting the sodium salt of alphahydroxy-octadecyl-phosphonic acid and potassium hexacyanoferrate with benzidine hydrochloride, is mixed with kieselguhr (as a carrier material) and with a solution containing ricinoleic acid diethylene triamine monoamide condensed with tertiary p-butyl phenol and formaldehyde, alpha-hydroxy-octadecyl-phosphonic acid, nitrocellulose and a vinyl chloridevinyl acetate copolymer in a mixture of butyl acetate, ethyl acetate, methyl acetate, acetone and methylethylketone to form a rust-preventing priming paint.