Patent GB-952868-A (GB)
Title: Preservation of cellulosic materials
Inventor: WEISS LUDWIG
IPC: D06M16/00
Filed: 1960-03-08
Abstract: Cellulosic materials, particularly cotton, hessian or flax fabrics, or paper or paper pulp, are preserved against attack by organisms causing decay by impregnating them with an organo-metallic compound formed by reacting a copper compound, and at least one metal or compound thereof from the group zinc, tin, cobalt, boron, mercury, bismuth, antimony or aluminium, with an organic complex-forming compound containing at least two of the elements nitrogen, sulphur and oxygen in a chain with at least one carbon atom.  The organo-metallic compound may be formed on the treated material, the components being applied in aqueous or organic solution or in emulsion.  Reducing agents may be included which reduce the copper, with or without the other metal component, to a lower valency state and render the treating material white or colourless.  The active compound may be used in a proportion of 0.3-3.0% of the dry cellulosic material.  Adhesion may be assisted by incorporation in the treating material of dextrin, starch, glue, casein, ethylcellulose, sodium carboxy methyl cellulose or polyacrylate or polystyrene emulsions. Waterproofing agents such as waxes, resins, and metallic salts and/or fireproofing agents such as borates, phosphates or antimonates may be added; additives specifically referred to are metal naphthenates and octoates, 8-hydroxy quinoline and 2, 2-methylene-bis (4-chlorophenol).  The treated materials are stated to be resistant to acids.  The Specification lists many examples of organic complex-forming compounds containing carbon-sulphur-oxygen, carbon-sulphur-nitrogen and carbon-nitrogen-oxygen linkages.  In representative examples, (1) Cotton duck is treated in succession with a cuprammonium solution and partially dried, an aqueous bath of potassium cyanate and a minor quantity of sodium pentachlorphenate, and a 5% solution of aluminium sulphate, and is repeatedly washed in successively cooler water, pressed and dried; the product is white and rot-resistant.  (2) Hessian fabric is padded in succession through aqueous baths of thiazole-carboxylic acid methyl ester, copper sulphate, stannous chloride and sodium carbonate, washed and dried.  (3) Flax fabric is treated with cuprammonium solution and partially dried, and is then treated in succession in aqueous baths containing respectively barium thiocyanate plus antimonyl chloride, and sulphocyanoacetone, and dried; the product is rot- and fire-resistant.  (4) Hessian fabric is treated in an aqueous bath containing cuprammonium and copper, zinc and calcium naphthenate, and partly dried, and is then passed quickly through a bath containing an aqueous emulsion of barium thiocyanate, thiophene dicarboxylic acid and hydrooxylamine formate; the washed and dried product is white, rot resistant and fast to sunlight.  (5) Cotton duck is rendered white, waterproof and rot-resistant by treatment in succession in a bath containing bismuth nitrate and ammonium zincate, an emulsion of copper stearate and ammonium thiocyanate, and a bath of sodium stannate, and washing and drying.