Patent GB-827646-A (GB)
Title: Process for delustring textile materials
Inventor: HAYCOCK PETER HOWARD
IPC: D06M11/71
Filed: 1955-04-30
Abstract: Textile materials are impregnated successively in either order with two aqueous solutions: (a) containing an acid salt of a polybasic acid having a dissociation constant in water of not less than 10-6; and (b) containing a salt of an acid stronger than the said polybasic acid with a metal of which a "less acid" salt with the said polybasic acid will first separate from an aqueous solution of an acid salt therewith on removal of water, either solution containing the ingredients of an amino-aldehyde condensation product, and thereafter the fabric is dried.  The phase "less acid" salt includes neutral salts.  Solution (a) may comprise a sodium, potassium or ammonium acid salt of phosphoric, phosphorous, pyrophosphoric, malonic, oxalic, maleic, tartaric or phthalic acid and solution (b) may comprise a salt of barium, calcium, strontium, thorium, zinc, copper, manganese, cadmium, cerium, magnesium, lead or UO2 and hydrochloric, sulphuric or nitric acid.  It is stated that a less-acid salt of the metal from (b) and the acid from (a), e.g. the monohydrogen-phosphate, is formed upon the fabric and acts as a catalyst in the production of an aminoaldehyde condensate in particulate form upon the textile.  A buffer may be included in either solution.  A list of suitable systems is given.  The amino-aldehyde ingredients may be urea or melamine and formaldehyde or paraformaldehyde or partial condensates thereof, and a minor proportion of methylol ethers of urea- or melamine-formaldehyde condensates may be included in the solution.  In Example (1) a viscose rayon fabric is printed with a paste comprising a gum, trisodium phosphate, a reducing agent, urea, glycerol and a dye, steamed at 100 DEG  C., dried, immersed in a solution of sodium dihydrogen phosphate, mangled and dried, impregnated with a solution containing lead nitrate and urea-formaldehyde precondensate, mangled, dried and baked at 140 DEG  C.  The dyestuff is then re-oxidized with sodium perborate and the printed area relustred with hydrochloric acid.  Example (2) is similar except that the printing paste does not contain trisodium phosphate and in Example (3) two printing pastes are employed one containing trisodium phosphate and one, not.  In Example (5), a viscose rayon fabric is impregnated with sodium dihydrogen phosphate, mangled, dried, impregnated with a solution containing a urea-formaldehyde pre-condensate (molar ratio of formaldehyde to urea 1.6), lead nitrate and a wetting agent, mangled and dried. The materials treated may also be fibres, yarns or fabrics of natural silk and cellulose ethers or esters.  Specifications 467,480 and 827,645 are referred to.ALSO:Textile materials are impregnated successively in either order with two aqueous solutions, (a) containing an acid salt of a polybasic acid having a dissociation constant in water of not less than 10-6 and (b) containing a salt of an acid stronger than the said polybasic acid with a metal of which a "less acid" salt with the said polybasic acid will first separate from an aqueous solution of an acid salt therewith on removal of water, either solution containing the ingredients of an amino-aldehyde condensation product, and thereafter the fabric is dried.  The phrase "less acid" salt includes neutral salts.  Solution (a) may comprise a sodium, potassium or ammonium acid salt of phosphoric, phosphorous, pyrophosphoric, malonic, oxalic, maleic, tartaric or phthalic acid and solution (b) may comprise a salt of barium, calcium, strontium, thorium, zinc, copper, manganese, cadmium, cerium, magnesium, lead or UO2 and hydrochloric, p sulphuric or nitric acid.  It is stated that a less acid salt of the metal from (b) and the acid from (a), e.g. the monohydrogen-phosphate, is formed upon the fabric and acts as a catalyst in the production of an amino-aldehyde condensate in particulate form upon the textile.  A buffer may be included in either solution.  A list of suitable systems is given.  The amino-aldehyde ingredients may be urea or melamine and formaldehyde or paraformaldehyde or partial condensates thereof, and a minor proportion of methylol ethers of urea- or melamine-formaldehyde condensates may be included in the solution.  In Example (1) a viscose rayon fabric is printed with a paste comprising a gum, trisodium phosphate, a reducing agent, urea, glycerol and a dye, steamed at 100 DEG  C., dried, immersed in a solution of sodium dihydrogen phosphate, mangled and dried, impregnated with a solution containing lead nitrate and ureaformaldehyde precondensate, mangled, dried and baked at 140 DEG  C.  The dyestuff is then reoxidized with sodium perborate and the printed area relustred with hydrochloric acid.  Example (2) is similar except that the printing paste does not contain trisodium phosphate and in Example (3) two printing pastes are employed, one containing trisodium phosphate and one, not.  In Example (5), a viscose rayon fabric is impregnated with sodium dihydrogen phosphate, mangled, dried, impregnated with a solution containing a urea-formaldehyde precondensate (molar ratio of formaldehyde to urea-1.6), lead nitrate and a wetting agent, mangled and dried. The materials treated may also be fibres, yarns or fabrics of natural silk and cellulose ethers or esters.  Specifications 467,480 and 827,645 are referred to.