Patent GB-380518-A (GB)
Title: Method of improving the durability of nitrocellulose coating compositions and films
IPC: C09D101/18
Filed: 1931-06-19
Abstract: Nitrocellulose coating-compositions or films, not containing drying-oils or alkyd resins modified by combination with drying-oil acids, are rendered more resistant to ultra-violet light present in sunlight by incorporating an organic salt (other than a lake or dye) of iron, copper or cobalt, which is compatible with the nitrocellulose and soluble in organic solvents.  The films absorb ultra-violet-light and may transmit, for example, only 10 per cent at 3130  .U., or 25 per cent for the entire range present in sunlight. The compositions may be clear lacquers, enamels, or plastics, and may form the connecting film in laminated glass.  The quantity of the organic salt may be 1 part to 4 parts of nitrocellulose, and should seldom exceed 1 part to 1 part of nitrocellulose.  Salts particularly suitable are those of an aliphatic or alicyclic acid, a higher fatty acid, a drying-oil acid (linseed, chinawood), a semi or non-drying oil acid (castor, cotton seed), or a half-ester of a dibasic acid, and camphorates, naphthenates, resinates, abietates.  Salts specified are ferric linoleate, the ferric salt of castor-oil acids, copper ethyl succinate, ferric butyl camphorate, ferric oleate, basic ferric acetate, ferric ethyl succinate, ferric naphthenate, ferric resinate, ferric abietate, copper abietate, and cobalt abietate. A suitable lacquer contains 20-25 per cent of nitrocellulose in a solvent mixture consisting of ethyl acetate, butyl acetate, toluene, and alcohol; gums, alkyd resins, softeners, and pigments may be added; and the organic salt is then added, preferably in solution, e.g. in toluene or butyl alcohol.  The Specification as open to inspection under Sect. 91 (3) (a) states also that zinc butyl phthalate and organic salts of the following metals have been incorporated in nitrocellulose films: K, Mg, Al, Cr, Mn, Zn, Zr, Cd, Sn, Ba, Hg, Pb, Bi, Th, U, Nd, but are ineffective or less effective than the salts of copper, iron, and cobalt for absorbing ultra-violet light.  This subject-matter does not appear in the Specification as accepted.ALSO:Nitrocellulose coating-compositions or films, not containing drying oils or alkyd resins modified by combination with drying-oil acids, are rendered more resistant to ultra-violet light present in sunlight by incorporating an organic salt (other than a lake or dye) of iron, copper, or cobalt, which is compatible with the nitrocellulose and soluble in organic solvents.  The films absorb ultra-violet light, and may transmit, for example, only 10 per cent at 3130 A DEG .U., or 25 per cent for the entire range present in sunlight.  The compositions may be clear lacquers, enamels, or plastics, and may form the connecting film in laminated glass.  The quantity of the organic salt may be 1 part to 4 parts of nitrocellulose, and should seldom exceed 1 part to 1 part of nitrocellulose.  Salts particularly suitable are those of an aliphatic or alicyclic acid, a higher fatty acid, a drying-oil acid (linseed, chinawood), a semi- or non-drying oil acid (castor, cotton seed), or a half-ester of a dibasic acid, and camphorates, naphthenates, resinates, abietates.  Salts specified are ferric linoleate, the ferric salt of castor oil acids, copper ethyl succinate, ferric butyl camphorate, ferric oleate, basic ferric acetate, ferric ethyl succinate, ferric naphthenate, ferric resinate, ferric abietate, copper abietate, and cobalt abietate. A suitable lacquer contains 20-25 per cent of nitrocellulose in a solvent mixture consisting of ethyl acetate, butyl acetate, toluene, and alcohol; gums, alkyd resins, softeners, and pigments may be added; and the organic salt is then added, preferably in solution, e.g. in toluene or butyl alcohol.  The iron, cobalt and copper salts may be prepared by treating an aqueous or alcoholic solution of a salt of the metal with the sodium or potassium salt of the organic acid or half-ester.  Thus, ferric ethyl succinate is prepared by heating together alcoholic solutions of anhydrous ferric chloride and potassium ethyl succinate, evaporating to dryness, extracting the residue with a p  mixture of equal quantities of toluene and n-butyl alcohol, and removing the solvent by distillation.  The Specification as open to inspection under Sect. 91 (3) (a) states also that zinc butyl phthalate and organic salts of the following metals have been incorporated in nitrocellulose films:--K, Mg, Al, Cr, Mn, Zn, Zr, Cd, Sn, Ba, Hg, Pb, Bi, Th, U, Nd, but are ineffective or less effective than the salts of copper, iron, and cobalt for absorbing ultra-violet light.  This subject-matter does not appear in the Specification as accepted.