Patent GB-1038306-A (GB)
Title: Process of treating wool
IPC: D06M15/59
Filed: 1964-11-18
Abstract: 1,038,306. Shrinkproofing wool. ARTHUR. D. LITTLE Inc. Nov. 18, 1964 [Nov. 20, 1963], No. 47024/64. Addition to 913,370. Headings D1L and D1P. Wool is shrinkproofed by subjecting it in continuous operation to serial impregnation with (a) a solution of a diamine in water and then with (b) a solution of a diacid chloride, a bischloroformate or a diisocyanate in an inert, water-immiscible solvent, a portion of solution (b) being continuously withdrawn and continuously treated to remove water, hydrolysis products and suspended matter and being continuously returned to solution (b) after removal of the water, hydrolysis products and suspended matter. A polymer is produced at the interface between the liquids (a) and (b) and is formed in situ on the fibres. The water, hydrolysis products, e.g. hydrogen chloride, dicarboxylic acids and/or dicarboxylic acid monochlorides, and suspended matter, e.g. gummy or resinous materials may be removed from the withdrawn portion of (b) by passing it through a plate-type filter precoated with a diatomaceous earth filter aid and through a dehydrating agent which preferably has the ability to absorb hydrogen chloride as well as water, e.g. calcium chloride or sulphate, silica gel, alumina, charcoal, activated carbon, bentonites, attapulgite and porous glasses and molecular sieves such as alumino-silicate zeolites. Molecular sieves are preferably used in conjunction with other agents or devices, e.g. screens or beds of sand or diatomaceous earth and ion exchange resins. The molecular sieve may be regenerated by back-washing with a warm alkaline solution containing a surface-active agent and heating by forcing hot gas, e.g. air or nitrogen, through the sieve. The solvent used to prepare solution (b) may be benzene, carbon tetrachloride, toluene, xylene, ethylene dichloride chloroform, hexane, octane or petroleum ether. Either solution (a) or (b) may contain a catalyst, e.g. pyridine, dimethyl aniline, quinoline, an alkali metal hydroxide, sodium carbonate or bicarbonate, trisodium phosphate, borax or excess diamine, to remove the hydrogen chloride in the case where a diacid chloride or bischloroformate is used, tributyl trichloride, boran trifluoride-diethyl ether complex, stannous tartrate, ferric chloride, titanium tetrachloride or tin laurate or myristate. The diamine solution may also contain a surface active agent, e.g. sodium alkyl (C 8 -C 18 ) sulphates, sodium alkane (C 8 -C 18 ) sulphonates, sodium alkyl (C 8 -C 20 ) benzene sulphonates, esters of sulphosuccinic acid, soaps and reaction products of ethylene oxide with fatty acids, polyhydric alcohols, partial esters of fatty acids with polyhydric alcohols or alkyl phenols and/or a supplementary solvent, e.g. acetone, in a quantity sufficient to disperse the active reactant. In Fig. I the fabric 6 is passed through the diamine solution 2 in tank 1 which is provided with heating jacket 9, excess solution is removed by pad rolls 10 and returned via trough 8 to tank 1,  and the fabric is then passed through the diacid chloride solution 4 in tank 3, excess solution being removed by pad rolls 11 and collected in trough 12. Diacid chloride solution is continuously withdrawn from tank 3 by pump 16 and together with the solution collected in trough 12 is passed up through the purification system comprising column 13 packed with beads 14 of a water-absorbing zeolite or other molecular sieve supported on screen 15, and returned via pipe 19 back to tank 3. A plate-type filter pre-coated with a diatomaceous earth filter aid may be interposed between pump 16 and column 13.