Patent GB-766864-A (GB)
Title: Improvements in or relating to polysiloxane compositions for treating organic fabrics
IPC: D06L1/04
Filed: 1955-03-24
Abstract: A composition for waterproofing, and shrinkproofing textiles and rendering them resistant to grease-spotting and solvent-spotting, consists essentially of a mixture of (1) 5-75 per cent by weight of a liquid or hydrocarbon solvent-soluble polysiloxane having from 0.05 to 1 silicon-bonded hydrogen atoms per silicon atom, and a total of from 1.6 to 2.5 total hydrogen and hydrocarbon radicals per silicon atom (the radicals being aliphatic up to 5 carbon atoms and up to 0.1 aryl radicals per silicon atom); and (2) 25-95 per cent of an hydroxylated polysiloxane having a viscosity less than 1,000,000 cs. and from 1.4 to 2 hydrocarbon radicals per silicon atom, of which up to 0.1 may be aryl and the remainder aliphatic up to 5 carbon atoms. The composition may also contain minor amounts of monorganosiloxane resins, urea-formaldehyde, melamine-formaldehyde, vinyl acetate and acrylonitrile resins.  In Example (1) the shrinkage after successive washings of a wool fabric treated with two compositions of the invention is compared with that of the same fabric treated with similar compositions but in which the second polysloxiane is not hydroxylated.  Each compositions contained 2 per cent lead 2-ethyl hexoate.  The polysiloxanes were dimethyl polysiloxanes and methylhydrogen polysiloxanes.  The compositions were cured in the fabric by heating at 300 DEG  F. for 10 minutes.  Examples (2), (3) and (4) also utilize dimethyl and methylhydrogen polysiloxanes.  In Examples (5) copolymers of 90 mol. per cent Me2SiO, 9.5 mol. per cent HSiO 3/2 and 0.5 mol. per cent C6H5Me2 SiO 1/2 ; 99.5 mol. per cent C3H7SiO and 0.5 mol. per cent (CH3)2HSiO 1/2 ; and 0.1 mol. per cent C5H11(CH3)2SiO 1/2 , 55 mol per cent (C2H5)2SiO and 44.9 mol. per cent CH3HSiO were used instead of methylhydrogen polysiloxane. Example (6) refers to the use of hydroxyl terminated diethyl, diamyl and ethylmethylpolysiloxanes and a copolymer of 95 mol. per cent dimethylsiloxane and 5 mol. per cent diphenyl siloxane, also hydroxyl terminated.  Example (7) uses a mixture of a copolymer of 70 mol. per cent dimethylsiloxane and 30 mol. per cent monomethylsiloxane containing 0.36 per cent hydroxyl groups and a trimethyl endblocked methyl hydrogen polysiloxane, and Example (8) uses a similar hydroxyl-containing polysiloxane.  The compositions may be in the form of solutions or emulsions. Specifications 680,265, 686,212 and 762,819 are referred to.ALSO:Wool fibres are treated with a mixture of (1) 5-75 per cent by weight of a liquid or hydrocarbon solvent soluble polysiloxane having from 0.05 to 1 silicon-bonded hydrogen atoms per silicon atom and a total of from 1.6 to 2.5 hydrogen and hydrocarbon radicals per silicon atom (the radicals being aliphatic up to 5 carbon atoms and up to 0.1 aryl radicals per silicon atom), and (2) 25-95 per cent of an hydroxylated polysiloxane having a viscosity of less than 1,000,000 cs. and from 1.4 to 2 hydrocarbon radicals per silicon atom of which up to 0.1 may be aryl and the remainder aliphatic up to 5 carbon atoms (see Group IV(a)).  The composition may also contain minor amounts of mono-organosiloxane resins and ureaformaldehyde, melamine - formaldehyde, vinyl acetate and acrylonitrile resins.  The compositions may be used in solution or emulsion.  In examples compositions according to the invention are used to treat wool flannel shirting and wool gabardine.  In each case the composition was cured on the fabric.  In one example comparative results are given for fabrics treated with compositions containing a trimethyl end-blocked polysiloxane instead of a hydroxylated polysiloxane.  Other fabrics may be treated to obtain water repellency and to improve resistance to grease spotting (see Group VIII).