IMPROVEMENTS IN THE TREATMENT OF LEATHER

摘要

1,256,335. Proofing leather. HENKEL & CIE G.m.b.H. 26 June, 1970 [27 June, 1969], No. 31060/70. Heading DIP. [Also in Division C6] Leather is impregnated with a composition which comprises a solution of: A a condensation product of an aluminium alcoholate of a lower monoalcohol of chain lengths C 1 to C 4 with a phosphoric acid monoester of a higher fatty alcohol of chain lengths C 12 to C 20 , and B. a fluoro-carbocyclic acid or an ester thereof, or a fluoro-alcohol or an ester, ether or acetal thereof, which has a fluorinated lipophile residue having a chain length of C 8 to C 20 , in an organic solvent. The solvent is preferably a gasoline fraction having a boiling range of 60 to 200 degrees C, ethyl acetate, butyl acetate, trichloroethylene or toluene. In a preferred example component A comprises a reaction product of 1 mole of aluminium isopropylate and 0.7 to 1.5 moles of a monoalkyl phosphoric acid ester mixture of chain lengths C 12 to C 18 , dissolved in perchloroethylene, and component B is a mixture of perfluorooctane carbocylic acid and a methacrylic acid ester of a fluorinated unsaturated fatty alcohol mixture having an average chain length of C 8 , dissolved in methyl chloroform. The two components may be mixed in various proportions such that the proportion of component B is in the range 5 per cent to 90 per cent by weight, preferably between 10 and 50 per cent by weight. The composition may additionally include a stabilizer, e.g. acetyl acetone or ethyl acetoacetate, and may further include dimethyl polysiloxane, or/and a wax, resin or. dye. The composition may also be varied by replacing part of the phosphoric acid monoester in component A with a corresponding phosphoric acid diester.