Patent GB-561152-A (GB)
Title: Improvements in process for treating fabrics with synthetic resins
IPC: D06M15/39
Filed: 1942-10-22
Abstract: A fabric, such as a knitted fabric which may be in the form of a stocking, is immersed in an aqueous bath containing particles of a synthetic resin which have been agglomerated from the dispersed state to the form of flocks which are readily separable from the aqueous medium on standing and which are capable of depositing on the fabric on contact therewith, and the fabric is associated with the bath until at least part of the flocculated particles of synthetic resin have been deposited on the fabric.  The treatment renders a knitted fabric resistant to laddering, and it improves the wearing qualities and appearance.  The resin may be a phenol-or urea-aldehyde, polymethacrylate, polyvinyl ester, terpene polymer or ester gum.  The water dispersion of the resin may be prepared from the solid resin by treatment in a colloid mill, or by milling in presence of a hydrophyllic colloid and water, or the resin may be prepared by condensation or polymerisation in an aqueous medium.  The resin may be agglomerated from the dispersed condition by the addition of precipitating agents in the presence of a sufficient amount of a protective agent or stabilizer to prevent the resin particles from completely coagulating into a coherent lump.  Ammonium sulphate or similar salt may be used for agglomerating the resin particles. Preferably the resin dispersion contains clay and a protein such as gelatine.  Another method of agglomerating the resin particles is to precipitate a flocculant salt or acid in the dispersion of synthetic resin as by precipitating a polyvalent metal silicate or silicic acid gel in the dispersion of resin and in presence of a protective substance.  The protective substance may be one of the well-known stabilizers for colloidal dispersions, e.g. a carboxylate, sulphonate, sulphinate, phenolate, or ethereal sulphate, having an aliphatic, or aromatic group, which may contain substituent halogen, amine, nitro, or hydroxyl groups. Preferably the protective substance is of the formula R-SO3M, where R is an organic radical containing at least one group containing more than 8 carbon atoms and M represents alkali metal, hydrogen, or ammonium.  Several examples of such compounds are specified including compounds of the formulae:-C10H21O-SO3Na to C18H37O-SO3 Na, C12H25-SO3Na lauryl sodium sulphonate, C16H33-SO3Na cetyl sodium sulphonate, C17H33OC2H4-SO3Na, C17H33COOC2H4-SO3Na, C17H33COOC2H4-O-SO3Na C17H33 CO-NH-C2H4-SO3Na, alkyl naphthalene sulphonates, hydrogenated anthracene sulphonates, hydrogenated naphthalene sulphonates, and compounds of the formula:- <FORM:0561152/IV/1> in which one of the groups R1, R2 is an alkyl radical from C3H7 to C8H17 and the other i also such a radical or is hydrogen.  Woven or knitted fabrics may be treated with the resin flock bath and they may comprise fibres of silk, wool, cotton, linen, viscose rayon, acetate rayon, or nylon. After the treatment, the fabrics may be rinsed or washed and dried.  The bath of resin agglomerates may be of acid reaction and with such a bath the agglomerates become firmly anchored in the fibres on deposition. Small amounts of acid may be added during the treatment.  If the bath is not acid, the fabric should be rendered acid or should be dried before rinsing.  In an example, an aqueous dispersion of methacrylic acid polymers containing Aquarex D, a stabilizer having the composition of mono sodium sulphate ester of a half lauryl and half myristyl alcohol, and containing gelatine and a dispersion of clay, is treated with ammonium sulphate solution so as to form flocks of agglomerated resin particles.  Rayon stockings enclosed in a cotton bag are immersed in the bath and agitated.  Small amounts of formic acid are added during the treatment.  The stockings are removed, washed and dried.  In another example, the treating bath is made up with Aquarex D, "Nypene Emulsion 1802" (an aqueous dispersion of an alicyclic resin consisting of a terpene polymer), clay dispersion, and gelatine, mixed with ammonium sulphate to flocculate the resin. In another example, the treating bath is prepared from an aqueous dispersion of polyvinyl acetate, Aquarex D, clay dispersion, and gelatine, flocculation being effected by adding ammonium sulphate.