Patent GB-600222-A (GB)
Title: Improvements in or relating to the finishing of lace and net fabrics and the like
IPC: D06M15/423
Filed: 1945-09-11
Abstract: Net fabric is rendered resistant to distortion by laundering by impregnation in an emulsion of a blend of a water-insoluble organic solvent-soluble phthalic anhydride-polyhydric alcohol resin with a water-insoluble organic solvent-soluble alkylated melamine- (or urea-) formaldehyde resin dispersed in an aqueous solution of a water-soluble methylated methylol melamine resin, drying and heating to cure the resins in the fabric.  The total amount of resin fixed on the fabric is usually 4-25 per cent based on the dry weight of the fabric; 2-10 per cent of methylated methylol melamine resin is used, and the blend, comprising 30-85 per cent phthalic-anhydride-polyhydric alcohol resin and 70-15 per cent of alkylated melamine-or urea-formaldehyde resin, is used preferentially in amounts of 1-2 times the weight of the methylated methylol melamine resin. Emulsifying agents such as glue, ammonium caseinate and curing accelerators such as a mixture of equal parts of di-ammonium hydrogen phosphate and hexamethylene tetramine may be used.  Dyes and pigments for tinting and toning such as Calcophyl Ecru may also be added.  In an example, an aqueous solution of ammonium caseinate is prepared from 1.8 parts by weight of concentrated ammonia, 2.6 parts casein and 62.2 parts water and allowed to stand for several hours, and then poured slowly into a vigorously stirred blend of 18.1 parts of a xylol solution of butylated melamine formaldehyde and 15.3 parts of a solution in the hydrocarbon solvent known as "Solvesso No. 2" of phthalic anhydride-glycerine-soya bean fatty acids resin at 30 DEG  C.  The agitation is continued until a uniform emulsion is obtained.  10 parts of this stable emulsion are diluted to 100 parts with water and 11 parts of methylated methylol melamine resin added until completely dissolved.  A curing accelerator consisting of equal parts of di-ammonium hydrogen phosphate and hexamethylene tetramine is added to the amount of 0.3 per cent of the emulsion. Net fabrics are padded through this emulsion at 27-37 DEG  C. (the pick-up being 100-150 per cent of the weight of the goods), frame dried at 70 DEG  C. and cured for 3-5 minutes at 148 DEG  C.  The finished fabric may be given a light wash in 1/2 per cent soap and soda-ash at 48 DEG  C. followed by rinsing and frame drying at 70 DEG  C.  The various resins used may be prepared by the processes described in Specification 600,218.ALSO:Net fabric is rendered resistant to distortion by laundering by impregnation in an emulsion of a blend of a water-insoluble organic solvent-soluble phthalic anhydride-polyhydric alcohol resin with a water-insoluble organic solvent-soluble alkylated melamine- (or urea-) formaldehyde resin dispersed in an aqueous solution of a water - soluble methylated methylol melamine resin, drying and heating to cure the resins in the fabric.  The total amount of resin fixed on the fabric is usually 4-25 per cent based on the dry weight of the fabric : 2-10 per cent of methylated methylol melamine resin is used, and the blend, comprising 30-85 per cent phthalic-anhydride-polyhydric alcohol resin and 70-15 per cent of alkylated melamine- or urea-formaldehyde resin, is used preferentially in amounts of 1-2 times the weight of the methylated methylol melamine resin. Emulsifying agents such as glue, ammonium caseinate and curing accelerators such as a mixture of equal parts of di-ammonium hydrogen phosphate and hexamethylene tetramine may be used.  Dyes and pigments for tinting and toning such as Calcophyl Ecru may also be added.  In an example, an aqueous solution of ammonium caseinate is prepared from 1.8 parts by weight of concentrated ammonia, 2.6 parts casein and 62.2 parts water and allowed to stand for several hours, and then poured slowly into a vigorously stirred blend of 18.1 parts of a xylol solution of butylated melamine formaldehyde and 15.3 parts of a solution in the hydrocarbon solvent known as "Solvesso No. 2" of phthalic anhydride-glycerine-soya bean fatty acids resin at 30 DEG  C.  The agitation is continued until a uniform emulsion is obtained.  10 parts of this stable emulsion are diluted at 100 parts with water and 11 parts of methylated methylol melamine resin added until completely dissolved.  A curing accelerator consisting of equal parts of di-ammonium hydrogen phosphate and hexamethylene tetramine is added to the amount of 0.3 per cent of the emulsion. Net fabrics are padded through this emulsion at 27-37 DEG  C. (the pick-up being 100-150 per cent of the weight of the goods), frame dried at 70 DEG  C. and cured for 3-5 minutes at 148 DEG  C.  The finished fabric may be given a light wash in 1/2 per cent soap and soda-ash at 48 DEG  C. followed by rinsing and frame drying at 70 DEG  C.  The various resins used may be prepared by the processes described in Specification 600,218.