Patent GB-596362-A (GB)
Title: Improvements relating to the production of toxic compounds and their use in the treatment of textiles for protection against biological attack
IPC: D06M16/00
Filed: 1944-01-29
Abstract: A toxic compound of pentachlor-phenol and a protein constituting textile fibre or contained in or applied to textile fibre is prepared by bringing the pentachlor-phenol dispersed in an aqueous acid medium into contact with the protein in or on the fibre and drying the treated fibre, and establishing during the process before the fibre is completely dry a pH value within the range of 4 to 7 at which the desired compound is formed.  Thus, in treating protein fibres, an aqueous dispersion of pentachlor-phenol is prepared by adding finely-divided pentachlor-phenol to a solution of a volatile acid or by precipitating the phenol from a solution of its sodium or potassium salt by means of a volatile acid in the presence of a protective colloid, and woollen goods are then passed through the resultant suspension and thereafter dried, so expelling the volatile acid and establishing the required pH value for formation of the toxic compound; the suspension may also contain polyvalent metal salts of volatile acids.  When using an added protein, the latter, which may be partially demerized, is dispersed in an aqueous solution of sodium pentachlor-phenolate having a pH of at least 8 in absence of ammonia or its salts and cloth is impregnated with the mixture and then, with or without previous drying, is passed through a solution of a volatile acid or heat decomposable salt thereof and thereafter dried.  Alternatively, a protein solution containing up to 2 per cent sodium pentachlor-phenolate is treated with a slight excess of volatile acid, with or without a heat-sensitive salt, so forming a precipitate in emulsion form through which woollen or cotton cloth is passed and thereafter dried as before.  Instead of using excess of volatile acid or salt thereof as above, there may be used an aqueous dispersion having a pH within the specified range when applied to the fibre, formation of the toxic compound then commencing at once. Woollen goods may be treated according to p  these methods at any of the stages of acid milling, finishing and acid-dyeing.  The methods may be combined with a simultaneous water-proofing (see Group VIII). In examples: (1) an aqueous suspension of pentachlor-phenol is prepared by adding excess formic acid to a solution of the phenol sodium salt in presence of glue or gelatine as a protective colloid, and woollen goods rendered moth-proof therewith, (a) in an acid-milling operation by adding the suspension to the mill, (b) in finishing by adding the suspension to the dolly and (c) in acid-dyeing from dyebaths containing the acid phenol suspension and an after-chrome-, neutral- or acid-dyestuff, for example, Fast chrome cyanine 2B, Coumassie blue N, Cyanine navy blue 2RNX, Elite fast red G or Cyanine fast scarlet 3B, in each case the desired toxic compound being formed on subsequently drying the treated wool; (2) cloth is padded through a solution of sodium pentachlorphenolate and demerized protein, obtained by treating an aqueous solution of glue or gelatine with pancreatin, and the impregnated cloth is then treated with a solution of formic acid, or (3) aluminium formate and dried; (4) the demerized protein-sodium phenolate solution of (2) is mixed with excess formic acid and, if desired, with aluminium formate, and the resulting cloudy liquor used direct in the padding mangle, the cloth being dried as before.ALSO:Insecticidal and fungicidal compositions comprise aqueous dispersions of pentachlor-phenol which may be obtained by adding the finely-divided phenol to an aqueous acid solution or by precipitating the phenol either from a solution of its alkali-metal salt in the presence of a protective colloid by means of a volatile acid such as formic acid with or without the addition of polyvalent metal salts of volatile acids, or from a solution of the alkali metal salt of the phenol and a protein, such as glue or casein, by addition of a volatile acid and, if desired, a heat-sensitive salt such as aluminium formate.  The compositions may also comprise aqueous solutions of an alkali metal pentachlorphenolate containing a protein and having a pH of at least 8 in the absence of ammonia or its salts.  The acid dispersions may also contain protein-wax emulsion or other water-repellents, such as are described in Specification 380,076, [Group VIII], and dyes such as an after-chrome dyestuff, for example, Fast chrome cyanine 2B, a neutral dyeing dyestuff, for example, Coumassie blue N or Cyanine navy blue 2RNX or an acid dyestuff, for example, Elite fast red G or Cyanine fast scarlet 3B, with the usual ingredients of acid dye-baths.