Treatment of fibres
United States Patent Massy et al.  
 TREATMENT OF FIBRES Inventors: Derek James Rowland Massy,  
 Linton; Kenneth Winterbottom, Whittlesford; Albert John Barber, Sale; James McCartney, Disley, all of England Assignee: Ciba-Geigy AG, Basle, Switzerland Filed: July 2, 1973 Appl. No.: 375,408  
 Related US. Application Data Continuation of Ser. No. 158.555. June 30, 1971. abandoned.  
 Foreign Application Priority Data July 2. 1970 United Kingdom 32241/70 US. Cl. 428/378; 428/419; 428/480;  
  427/341; 427/390 Int. Cl. B44d l/02; D06 13/28 Field of Search ..117/138.8 A, 138.8 F,  
 117/138.8 PV, 138.8 N, 138.8 UA, 139.5,  
  References Cited UNITED STATES PATENTS 6/1966 LeFave et 61.; 260/609 FOREIGN PATENTS OR APPLICATIONS 1.463.072 l1/1966 France Primary Examiner--P. E. willis Jr. Attorney, Agent. or Firm-Joseph G. Koloclny; Prabodh l. Almaula; Edward McC. Roberts [57] ABSTRACT A softer handle is imparted to fibres of polyesters and the like by treating them with a polythiol resin and curing the resin. The resistance to soiling and soil redeposition, and soil release properties, may also be improved. The resins employed contain at least two thiol groups per molecule linked via ester or ether groups to po1y(oxya1ky1ene) chains. I  
 v24 Claims, No Drawings TREATMENT OF FIBRES This is a continuation of application Ser. No. 158,555 filed on June 30, 1971 now abandoned.  
  This invention relates to a process for modifying synthetic materials in fibrous form, and to materials so treated.  
  It is well known to treat textiles comprising synthetic fibres with softening agents such as (1) polyethylene emulsions, (2) adducts of ethylene oxide with phenols or emines, and (3) cationic compounds such as C -C fatty amine or aminoamide salts. The softener is preferably applied to the wet fabric just after dyeing and it is highly desirable that it exhausts on to it. Many conventional agents fail in this respect, and even when exhaustion does occur, it is incomplete, a high proportion of the softener being wasted. Furthermore, a considerable amount of the softener is lost on washing the fabric.  
  It has now been found that, by the use of certain thiol-terminated poly(oxyalkylene) substances, synthetic fibrous materials having improved properties, in particular textiles having a fuller, softer, and more resilient handle and improved antisoil (including soil release and antisoil redeposition) and antistatic properties. It has also been found that these substances can exhaust onto the fibres surprisingly, in many cases practically quantitatively, and that the effects are resistant to washing and dry cleaning. These thiols may also serve as spinning lubricants and as knitting and weaving oils.  
  Accordingly, the present invention provides a process for modifying synthetic fibres which comprises 1. treating the fibres, in the absence of keratinous material, with a polythiol having at least two thiol groups per molecule and containing a. a radical of a polyhydric alcohol,  
 b. bound to this radical, at least two poly(oxyalkylene) chains,  
 0. bound through oxygen atoms to carbon atoms in the said poly(oxyalkylene) chains, at least two residues selected from the group comprising an acyl residue of a thiol-containing aliphatic carboxylic acid and the residue, after removal of a hydroxyl group, of a thiol-containing aliphatic alcohol,  
 and  
 2. curing the polythiol on the fibres.  
  The present invention further provides synthetic fibrous materials, in the absence of keratinous materials, bearing thereon a polythiol as aforesaid in the cured or still curable state.  
  If desired, the polythiol may be used in conjunction with an aminoplast, in which case treatment with, and curing, the aminoplast and the polythiol, can take place in any desired sequence. For example, the fibres may be impregnated with a mixture of the aminoplast and the polythiol, and then the aminoplast and polythiol are cured. Or the fibres may be impregnated first with the polythiol and then with the aminoplast, or vice versa, and then the aminoplast and polythiol are cured. Or an aminoplast can be cured on the fibres, which are then treated with the polythiol and the polythiol is cured. In place of the aminoplast, there may be used other resinous or resin-forming substances which can be crosslinked on the synthetic fibres, for example epoxide res- Synthetic fibres which may be subjected to the process of the present invention may be in the form of loose fibres, yarns, threads, woven, non-woven and knitted fabrics and garments, and woven and tuftcd carpets, needle-punched and other mechanical&#39;y formed fibrous floor-covering materials, and are preferably polyamides (nylons), polyesters, polyacrylonitriles, and polyvinyl alcohols. The term synthetic fibres is taken herein to include man-made fibres of cellulosic origin in which all three available hydroxyl groups per anhydrogluco unit have been chemically modified, e.g., by acylation, etherificatiom&#39;or cyanoethylation. Thus, cellulose triacetate is regarded, for the purpose of this invention, as a synthetic material.  
  Mixtures of two or more synthetic fibrous materials, or blends with cellulosic materials, may also be treated, but is should be clearly understood that blends of synthetic fibrous materials with keratinous material are not included within the scope of the present invention.  
  Polythiols used in the process of this invention contain two, three, and preferably not more than six, thiol groups per molecule. Especially good results have been obtained with those containing two or three thiol groups per molecule.  
  Preferred polythiols are those having a molecular weight between 400 and 10,000 particularly those of formula &#39;1 -&#34;r -(-Oalkylene OH i- R j q -(O-alkylene) O (CO) n X l in which m is an integer of at least 1 and may have different values in each of the p and q chains,  
 n is zero or 1,  
 p is a positive integer of at least 2 and at most 6 q is zero or a positive integer of 4 or less, selected so that (p-l-q) equals at least 2 and at most 6,  
  each alkylene group contains a chain of at least 2 and at most 6 carbon atoms between consecutive oxygen atoms,  
  R represents an aliphatic radical containing at least 2 carbon atoms,  
  and X represents an aliphatic radical containing at least one thiol group.  
  The oxyalkylene units in individual poly(oxyalkylene) chains may be different. They may be substituted, if desired, by e.g., phenyl or chloromethyl groups.  
  There may be thus used the partially or fully esterified compounds of the formula l E-o-alkenyb-y o. CO. C H SH in which R, alkylene, m, p, and q have the meanings Continued previously assigned, and r is a positive integer which may be as high as 18 or even 24. 1  
 Further preferred are esters of the formula CH H CH I (OC H O.COC H SH -(-O--alkenylene-)- OH R1 q CIZH b (OC H O.CO.C H SH CH (0C Hzt) OH (Oalkylene-)- O.CO.C H- SH t m &#39;CH (OC H O.CO.C H SH P in which alkylene, m, p, and q have the meanings previously assigned,  
 u is a positive integer of at most 2, 2 t and R represents an aliphatic radical having at least I 2 and at most 6 carbon atoms. l CH F t ZQm Yet further preferred are esters, of formula l (CH2) 2 l l l 7 CH (OC H O.CO.C H SH I (O-alkylene) OH 2 H m (O-alkylene) O.CO.C H SH T Qm p i 2 3O CH (OC H O.CO.C H SH 2 R \(O alkylene) OCOC H SH and 2 T and CH CH- OCH H O.CO.C H SH R o-alkylene) OCOC H SH 3 l t 2t u 2u.  
  p CH -(OC H O-CO.C H SH 3 in which m and u have the meanings previously assigned, and t is an integer of at least 2 and at most 3; in which and alkylene, m, and u have the meanings previously assigned,  
 p represents 2 or 3, CH O CH OCOCH SH q is zero or 1, such that (q +p equals 2 to 3, 2 2 4 )m 2 p denotes an integer of at least 3 and at most 6, H2)  
  R represents an aliphatic hydrocarbon radical hav- H (O (CH 4 OCOCH SH ing at least 3 and at most 6 carbon atoms. 7  
  Still further preferred are esters based on glycerol, hexane-1,2,5-triol, hexane-1,2,6-triol, ethylene glycol, or propylene glycol, and ethylene oxide and/or propylene oxide, or butane-1,4-diol and tetrahydrofuran, i.e., those of the formulae the polythiol having an average molecular weight between ],000 and 7500, where m has the meaning previously assigned.  
  Polythiol esters most preferred for the purposes of the present invention are those obtained from glycerol CH O z or propylene glycol, propylene oxide, and thioglycollic acid, i.e., of formula TH (oc n O.CO.C H SH CH (0C H O CO c H SH CH2 (oc n ococn sn 2 t 2t m o u CH (OC H ococn sn CH (oc n O.CO.C H SH l m CH2 (OC H ococn sn having a molecular weight within the range 1,000 to 5,000, or even 7,500,  
 (1H (OC H OCOCH SH CH (OC H OCOCH SH and CH CH (OC H OCOCH SH CH2 (OC H ICOCH SH having a molecular weight within the range 1,000 to 7,500, where m has the meaning previously assigned. Such esters are commercially available.  
  These thiol-terminated poly( alkylene oxide) esters are readily prepared by the reaction of a polyhydric alcohol with an alkylene oxide followed by partial or complete esterification of the terminal hydroxyl groups with a mercaptocarboxylic acid. suitable polyhydric alcohols include ethylene glycol, poly(oxyethylene) glycols, prepylene glycol, poly(oxypropylene) glycols, propane-l ,3-diol, poly(epichlorohydrin)s, butane-1,2- diol, butane-l ,3 -diol, butane-1,4-diol, butane-2,3-diol, poly(oxy-l, l-dimethylethylene) glycols, poly(tetrahydrofuran)s, glycerol, l,1,l-trimethylolethane, 1,1,1- trimethylolpropane, hexane-1,2,5-triol, hexane-1,2,6- triol, pentaerythritol, dipentaerythritol, mannitol, sorbitol, and adducts of alkylene oxides with ammonia or amines, such as diethanolamine and tetrakis(N-( 2- hydroxyethyl) )ethylenediamine. Suitable alkylene 0xides include ethylene oxide, propylene oxide, tetrahydrofuran and, less preferably, epichlorohydrin. If desired, the polyhydric alcohol may be treated with one alkylene oxide, say propylene oxide, and then tipped with a different alkylene oxide, such as ethylene oxide.  
  The preferred mercaptocarboxylic acids for the esterification are, as already indicated, thioglycollic acid (2-mercaptoacetic acid) and 2-mercaptopropionic acid, but other mercaptomonocarbocylic acids which may be used include mercaptoundecylic acid and mercaptostearic acid.  
  The second class of thiol-terminated poly(alkylene oxides) includes those of formula i l l I (Oalkylene)- OH l R q I &#39;(o-alk 1ene-)- OCHZCHCHZSH in which R denotes OHZ, --(O- alkylene) OH,O, CO, C H SH, or (O-alkylene) O.CO.C H Sl-l,  
  R,alkylene, m,p,q, and u have the meanings previously assigned,  
  and v is an integer of at least 1 and may have different values in each of the p chains.  
  The oxyalkylene units in the individual poly(oxyalhylene) chains may likewise be different, but are preferably the same, and may be substituted if desired, by, e.g., phenyl or chloromethyl groups.  
 Preferred among such ethers are those which are also ings previously assigned, and further preferred are those of the formula in which R R and 12 also have the meanings previously assigned.  
 The particularly preferred ethers are of formula (OC H OCH THCH SH in which R t, m, and p have the meanings previously assigned. The ethers of formula I in which R denotes Ol-l may be prepared in a known manner by reaction of an alkylene oxide with a polyhydric alcohol, etherification of the hydroxyl groups of the product with eipichlorohydrin, and treatment with sodium hydrosul phide to replace the chlorine by a sulphhydryl group (see US. Pat. No. 3,258,495, and United Kingdom Specification Nos. 1,076,725 and 1,144,761). In many cases the average number of thiol groups per molecule is not an integer but, for example, may be 2.6. This is attributable partly to the replacement of the chlorine atoms by the SH group not going to completion, and partly to side-reactions; for example, the chlorohydrin ether obtained by reaction with epichlorohydrin may also react with epichlorohydrin, so forming an ether with contains two replaceable chlorine atoms per hydroxyl group originally present in the polyhydric alcohol Ethers of formula O c H H CHCH SH CH (oc H OCH where m has the meaning previously assigned, especially such ethers having a molecular weight within the range 700 to 3,500 or up to 7,500.  
  The ether-esters of formula 1 in which R denotes O.CO.C l-l ,,Sl-l or(O-alkylene) O.CO.C H ,,Sl-l are obtainable by esterification of the corresponding alcohol with a mercaptocarboxylic acid HOOCC l-l- Sl-l.  
  Many of these polythiols are insoluble in water but can be applied as aqueous dispersions or emulsions. They may also be applied from organic solvents, for example, lower alkanols such as ethyl alcohol, lower ketones such as ethyl methyl ketone, benzene, and halogenated hydrocarbon solvents, especially chlorinated and/or fiuorinated hydrc carbons containing not more than three carbon atoms, such as the dry-cleaning solvents, carbon tetrachloride, trichlorothylene, and perchloroethylene.  
  The amount of the polythiol to be used depends on the effect desired. For most purposes from 0.1 to 10 percent by weight calculated on the weight of the material to be treated is preferred. The and, or handle, of the treated material will, of course, depend on the amount of polythiol employed and by simple experiment the least amount required to give the desired effect may readily be determined. Further, the composition of the fibres, and the construction of the fabrics, also influence the amount of polythiol required. Usually, a pick-up of from about 0.1 to 1 percent gives the required result.  
  When nminoplasts are employed in conjunction with the polythiols, they contain, per molecule, at least two groups of formula Cl-l OR directly attached to an amidic nitrogen atom or atoms, where R denotes a hydrogen atom, an alkyl group of from one to four carbon atoms, or an acetyl group. Examples of such aminoplasts are the N-hydroxymethyl, N-alkoxymethyl, and N-acetoxymethyl derivatives of the following amides and amide-like substances.  
 1. Urea, thiourea, and the cyclic ureas having the formula in which Y denotes either a group of formula or a divalent group containing from 2 to 4 carbon atoms in the chain, which may be substituted by methyl, methoxy, and hydroxy groups, and which may be interrupted by CO,-O--, or  
 where R denotes an alkyl or hydroxyalkyl group containing up to 4 carbon atoms,  
 and Q denotes oxygen or sulphur,  
  Examples of such cyclic ureas are ethyleneurea (imidazolidin-Z-one), dihydroxyethyleneurea (4,5- dihydroxyimidazolidin-Z-one), hydantoin, uron (tetrahydro-oxadiazin-4-one), 1,2-propylenurea (4- methylimidazolidin-Z-one), 1,3-propyleneurea (hexahydro-2l-l-pyrimid-2-one), hydroxypropyleneurea 5-hydroxyhexahydro-ZH-pyrimid- 2-one) dimethylpropyleneurea (5,5- dimethylhexehydro-2H-pyrimid-2-one), dimethylhydroxypropyleneurea and dimethylmethoxypropyleneurea (i.e., 4-hydroxyand 4-methoxy-5,5- dimethylhexahydro-2l-l-pyrimid-2-one), and 5-ethyland 5-(2-hydroxyethyl)-triazin-2-one.  
  ll. Carbonates and dicarbamates of aliphatic monohydric and dihydric alcohols containing up to four carbon atoms, e.g., methyl, ethyl, isopropyl, 2- hydroxyethyl, Z-methyxthl,2-hydroxy-n-propyl, and 3- hydroxy-n-propyl carbamates, and ethylene and 1,4- butylene dicarbamates.  
 lll. Melamine and other polyamino-l,3,5-triazines.  
  If desired, aminoplasts containing both N- hydroxymethyl and N-alkoxymethyl, or N- hydroxymethyl and N-acetoxymethyl groups, may be used, for example, a hexamethylol melamine in which from 1 to 5 of the methylol groups have been so etherified or esterified.  
  The aminoplast is usually applied as such but, if desired, when a urea-formaldehyde or melamineformaldehyde product is to be used, it may be formed in situ in a conventional manner from a ureaformaldehyde concentrate or melamine-formaldehyde concentrate and the requisite additional urea or melamine.  
  The aminoplasts employed are, in general, soluble in water and may be applied from aqueous solution; or they may be applied from aqueous emulsions, from solutions in the dry-cleaning solvents already mentioned, or from solutions in mixtures of water and a suitable cosolvent, such as methanol.  
  The proportions of the polythiol and the aminoplast can vary widely; usually there will be employed, per thiol group equivalent of the polythiol, from 2 to 50 or even 75, but usually from 5 to 40, N-methylol, N- alkoxymethyl or H-acetoxymethyl group equivalents of the aminoplast.  
  The desired effects may not be fully obtainable until substantially all the polythiol on the material has cured. At ordinary temperatures this may take from 5 to days or even longer. The curing reaction can, however, be accelerated greatly by the use of a catalyst and generally it is preferred to add the catalyst to the material to be treated at the same time as the polythiol is applied, although it may be added before or afterwards if desired. The curing time can be controlled by selecting an appropriate catalyst and the choice of curing time will depend on the particular application of the process according to the invention.  
  The catalysts may be bases, sicatives, sulphur, sulphur-containing organic compounds, and free-radical catalysts such as azodi-isobutyronitrile, peroxides and hydroperoxides, or combinations of these.  
  As organic bases there may be used primary or secondary amines such as the lower alkanolamines, e.g., monoand di-ethanolamine, and lower alkylene polyamines, e.g., ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, propane- ],2- and -l,3-diamine, and hexamethylenediamine. As inorganic bases there may be used the water-soluble oxides and hydroxide, e.g. sodium hydroxides, watersoluble, strongly basic salts such as trisodium phos phate, disodium tetraborate, and sodium carbonate, and also ammonia.  
  Sulphur-containing organic compounds which may be used as catalysts include those in which the sulphur atoms are not exclusively present as mercaptan groups, especially mercaptobenzothiazoles and their derivatives, dithiocarbamates, thiuram sulphides, thioureas, disulphides, alkyl xanthogen sluphides and alkyl xanthates.  
  Examples of siccatives are calcium, copper, iron, lead, cerium, and cobalt naphthenates.  
  Examples of suitable peroxides and hydroperoxides are cumene hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, dilauryl peroxide, methyl ethyl ketone peroxide, di-isopropyl peroxydicarbonate, and chlorobenzoyl peroxide.  
  Yet other catalysts are salts of a heavy metal with an acid having an acid strength (log pK) below 5 or chelates of a heavy metal, including chelates which are also salts. By heavy metal is meant one classified as heavy in Langes Handbook of Chemistry, revised 10th Edition, McGraw-I-Iill Book Co., at pp. 60 6l, that is, a metal of group IB, IIB, IIIB, lVB, VB, VIB, VIIB, or VIII, a metal of group IIIA having an atomic number of at least 13, a metal of group IVA having an atomic number of at least 32, or a metal of group VA having an atomic number of at least 51. Preferably the metal is a member of group IB, IIB, IVB, VB, VIB, VIIB, or VIII, particularly the first series of such metals, i.e. titanium, vanadium, chromium, manganese, nickel, and especially iron, cobalt, and copper. Suitable saltforming acids are mineral acids, especially hydrochloric, hydrobromic, nitric, sulphuric, phosphorous, and phosphoric acids, and organic acids such as chloroacetic, fumaric, maleic, oxalic, salicyclic, and, more especially, citric acid. Suitable chelating agents include those in which the chelatingatoms are oxygen and/or nitrogen, for example, 1,2,- and 1,3-diketones such as acetylacetone, alkylenediamines such as ethylenediamine, and more particularly, ethylenediaminetetraacetic acid.  
  The amount of catalyst used can vary widely. In general from 0.1 to 20 percent, preferably 1 to 10 percent, by weight based on the weight of the polythiol used is required, although much larger quantities can be used.  
  Curing of the polythiol takes place more rapidly at a pH of more than 7, e.g., from 7.5 to 12. Curing is also assisted by using elevated temperatures, eg from 30 to 180C or even higher: thus, the threated fibres may be heated at a temperature of 35 to C, but temperatures of above 180 to as high as 220C, may be met with if curing is combined with heat-setting. In high humidities curing is also accelerated.  
  The aminoplast, where one is added, may be cured under the usual conditions, i.e., at room temperature or at elevated temperatures. It may be desirable to include a catalyst for curing the aminoplast. Catalysts which may be used include latent acid compounds (which may be metal salts), or mixtures thereof, or certain basic substances. Ammonium salts which are latent acids, developing acidity in the mixture on heating, include ammonium chloride, ammonium dihydrogen phosphate, ammonium sulphate and ammonium thiocyanate. These ammonium salts may be used admixed with metal salts which also have a similar catalytic effect. Amine salts may also be used, e.g., 2-amino-2- methylpropanol hydrochloride. Among the suitable latent acid metal salts are zinc nitrate, zinc fluoroborate, zinc chloride, zirconium oxychloride, magnesium chloride, magnesium fluoroborate, or magnesium dihydrogen orthophosphate. These catalysts are generally used at concentrations of 0.3 to 5 percent by weight calculated on the weight of resin-forming materials of the aminoplast. There may also be used stronger acids such as hydrochloric or sulphuric acids which may be used as an aqueous solution (say, as 4- to 8- normal solutions) or which may be dissolved in a mixture of water and a solvent which is immiscible or partly miscible with water, and also acidic gases. Basic substances which may be used include sodium bicarbonate and sodium carbonate. When strong acid catalysts are used, in liquid or gaseous form, heating may not be necessary. In other cases, it may be necessary to heat the treated material, e.g., at a temperature of from 80 to 200C for from 30 seconds to 10 minutes, and preferably at from to 180C for from 2 to 7 minutes.  
  The polythiol, and the catalyst if used, can be applied to the material in conventional ways. For example, where fabric or yarn is to be treated, they may be padded on from a solution, emulsion, or suspension, or the material may be immersed in a bath. If garments or garment pieces are to be treated then it-is convenient to 1 1 spray them or to tumble them with the solution, emulsion, or suspension.  
  A particularly effective way of carrying out the process of this invention comprises immersing the fibres in an aqueous medium containing the polythiol and which is heated at a temperature in the range from to 95C. Exhaustion onto the fibres is favoured by working under slightly acid conditions, the aqueous medium having a pH in the range 3 to 6.  
  This denotes a poly(2-hydroxy-3-mercaptopropyl) ether prepared from a glycerol-propylene oxide adduct having an average molecular weight of about 4,800, epichlorohydrin, and sodium hydrosulphide. It had a mercaptan content of 0.32 equiv./kg, corresponding to 2.6 SH groups per average molecule.  
  Thiols C to L were prepared as described for Thiol A.  
 Their compositions are shown in Table I.  
 Table 1 Average mol. Esterifying Thiol Thiol Adduct of wt. of acid functionality polyol C Glycerol Propylene oxide 700 Thioglycollic 3 D Glycerol Propylene oxide 3000 Thioglycollic 3 E Glycerol Propylene oxide 6200 Thioglycollic 3 F Propylene glycol Propylene oxide 2000 Thioglycollic 2 G Glycerol Propylene oxide 4000 Thioglycollic 2 H Glycerol Propylene oxide 4000 Z-Mercaptopropionic 3 l l-lexane-1,2,  
  6-triol Propylene oxide l500 Thioglycollic 3 J Pentaerythritol Propylene oxide 2000 Thioglycollic 4 K Glycerol Propylene oxide i000 3-Mercaptoproprionic 3 L Butane-l,  
 4-diol Tetrahydrofuran l 000 Thioglycollic 2 Thiol G is a partial ester.  
  The compositions used in the process of this invention may also contain antisoiling, antistatic, bacteriostatic, rotproofing, flameproofing, or wetting agents. They may also contain water-repellents such as paraffin wax, of fluoroscent whitening agents.  
  The following Examples illustrate the invention. Unless otherwise specified, parts and percentages are by weight. The thiols used were prepared as follows: Thiol A A mixture of 800 g (0.2 g-mol) of a polyoxpropylene triol having an average molecular weight 4,000 and made from glycerol and propylene oxide (Polyol A), 55.2 g (0.6 g-mol.) of thioglycollic acid, 5 g of toluenep-sulphonic acid, and 350 ml of toluene was heated to reflux with stirring for 4 hours in an atmosphere of nitrogen. Water (108 ml, 0.6 g-mol). formed during the reaction was removed as its aseotrope with toluene, The mixture was cooled and washed with water, and the organic layer was separated. On removing under vacuum the solvent from the organic layer there remained 793 g (94 percent of the theoretical yield) of the desired tris(thioglycollate), (Thiol A), having a mercaptan content of 0.59 equiv./kg.  
 Emulsion A An aqueous emulsion of this thiol was then prepared.  
 Thiol A 500 g emulsifying agent 50 g sodium carboxymethylcellulose 5 g water 445 g The components were mixed at room temperature with a Silverson mixer until a uniform emulsion resulted. The emulsifying agent was an adduct of a mix-.  
 ture of C and C aliphatic primary amines 1 mole.) with ethylene oxide (70 mols.). This stock emulsion was then diluted with 99 parts of water to form Emulsion A.  
 Thiol B Thiol M is similar to Thiol B, but the glycerolpropylene oxide adduct used as the polyol had an average molecular weight of 700: Thiol M had a mercaptan content of 2.17 equiv./kg, corresponding to 2.3 SH groups per average molecule.  
  Emulsions C M were made as described for Emulsion A, substituting the same weight of the corresponding polythiol. Emulsion Z, used for purposes of comparison, was made by substituting a polyoxypropylene trio] of average molecular weight 4,000 (Polyol A) for Polythiol A.  
 Emulsions N and O Emulsions N and 0 were prepared from Thiols A and G respectively, by mixing at room temperature with a Silverson mixer the following:  
 Thiol A or G 500 g emulsifying agent 50 g sodium carboxymethylcellulose 5 g water 445 g The staining test referred to in the Examples con&#39; sisted of immersing the patterns in an aqueous solution, containing 2 g/l iodine and 20 g/l potassium iodide at room temperature for 30 seconds. The samples were washed in water for 10 seconds, pressed between filter papers to remove excess water, and then allowed to stand at room temperature for about 10 minutes. Staining was then assessed using the grey scale (British Standard 3.8. 2666: 1961 ISO Recommendation R /l/Part 3); a value of 5 denotes no change in colour, and l denotes a complete loss in colour, corresponding to no removal, and to complete removal, of the polythiol.  
 EXAMPLE 1 An impregnation liquor was prepared by adding 10 ml of Emulsion A to ml of water. The liquor was heated to 60C and a 10 g hank of yarn composed of short staple fibres of the polyester, polyethylene, terephthalate, was added. The temperature of the liquor was maintained at 60C for 30 minutes with continual movement of the yarn in the liquor by means of a glass EXAMPLE 4 An impregnation liquor was prepared, comprising the following:  
 rod. The liquor, which was initially milky in appear- 5 ance, became much clearer, showing that exhaustion of Emulsion A 20 ml the polythiol onto the fibres had occurred. The yarn hydrogen peroxide 40 ml was then removed from the liquor, spun in a spin dryer, 33 1 Strength) 340 ml and further dried at 70-80C. The yarn so treated had 10 a surprisingly high measure of softness and a pleasant Th li w h t d to 60C, and a 20 g-hank of&#39; silk-like handle. polyester yarn was immersed for 30 minutes during which time the temperature was maintained at 60C. EXAMPLE 2 The yarn was continually moved in the liquor and, after Three impregnation liquors were prepared, each being removed, it was spun in a spin dryer and dried at comprising the following: 70C. The impregnation liquor was virtually clear on removal of the hank, showing that almost complete exhaustion of the polythiol had occured. The yarn so EmulSiQnA m1 treated possessed a greatly improved handle, which monoethanolamine, 1% aqueous solution 5 ml water 175 ml 20 may be described as soft and silky.  
  f EXAMPLE 5 Three 10 g-pieces of a scoured polyester abric obtained under the designation Crimplene (Registered A plam weave tiabnc composed of polyester yams was treated according to the method of Example 4. Ex- Trade Mark) were carefully welghed and placed in the h th h t d t haustion of the impregnation liquor occurred, and the lmpregna quors w 10 i g sg O l l fabric so treated possessed a softer and more silk-like em temperamtes j 40 Q an handle. On creasing the treated fabric in the hand and quors were stirred while maintaining the respective releasing it, it was found to have greatly improved temperatures for 10 minutes The samples of the fabric springiness and recovery to its uncreased state f removed p f p dryer and f l drled pared with untreated material. Measurements of crease a5 Example 1 and Welghed- The followmg Increases recovery angles have confirmed this improvement, as in weight were recorded. shown by the following.  
 Sample Temperature of Treatment(C) Weight increase Crease Recovery Angles* (warp and weft) 1; Untreated polyester fabric 202 3 80 058 Polyester fabric treated by method of Example 4 238 All the treated samples of the fabric showed improved degrees of softness and handle compared with EXAMPLE 6 untreated fabric. A series of impregnation liquors was prepared consistin of, res ectivel the followin EXAMPLE 3 g p y g Three impregnation liquors were prepared exactly as Emulsion A 20 ml m Example 2, and &#39;p of polyester fabnc were monoethanolamine, 1% aqueous solution 0.2 ml carefully weighed and placed in the solution as before. water 179.8 ml The temperature of the solutions in this case were all o maintained at 60C, and times of treatment were requors were heated Q Scoured hanks P spectively 10, 30, and 90 minutes. After three times the f h t? fi i yams f l wellghmg 10 g i gg samples of the fabric were removed, dried and mg 6 o P matena p0 yester 6 1 re cellulose triacetate staple fibre yarn, acrylic staple fibre weighed. The following lncreases in weight were reb d d h d A ded yarn o tame un er t e esignatlon 01&#39;! an cor (Registered Trade Mark), and polyamide (nylon) hand knitting yarn, were immersed in the respective liquors and moved in the liquors which were maintained at Sample Ti of Tr ment in Weight ln r asem C for 30 minutes. The hanks were removed, and  
  60 dried as before. The hanks were then assessed for im- 4 1O 0 47 provements in handle as compared with the untreated 5 30 yarns. The effect on the polyester yarn was outstand- 6 90 0.60 ingly good, while pleasing softening effects were obtained on all the other material.  
  EXAMPLE 7 All the treated samples of the fabric showed improved degrees of softness and handle compared with untreated fabric.  
  Thiols A and B were applied to a variety of yarns from perchloroethylene solution. The yams were dipped into perchloroethylene solutions of the thiol at room temperature: the solutions also contained diethylenetriamine as catalyst. The yarns were then centrifuged so as to leave 1 percent by weight of the thiol and 0.02 percent by weight of diethylenetriamine. After being dried in an oven at 60C, the yarns were allowed to stand overnight in an atmosphere of 66 percent relative humidity at 20C before the handle was assessed according to the following classification:  
  No improvement compared with untreated 1 Slightly softer compared with untreated 2 Substantially softer than untreated 3 Very soft compared with untreated quors, having a pH of about 4, were prepared according to Table 2 below. Pieces g) of scoured Crimplene were immersed in a liquor for minutes at 60C. The liquors, which were originally milky in appearance, became clearer as treatment proceeded. The patterns were spun in a spin dryer without being rinsed, dried at 70C for 30 minutes, and then allowed to cure overnight. Fixation of the thiol was then assessed by either washing the patterns in water at 60C for 10 minutes containing 1 percent of a nonionic detergent or boiling them in hexane for 10 minutes, then staining the unwashed and washed patterns in iodine and assessing the difference in staining.  
 Handle after treatment with Yarn Thiol A Thiol B Polyester (Terylenc&#34;) 3 3 Polyamide (Nylon hand knitting) 3 3 Polyacrylic (Acrilan&#34;) 2 2 Cellulose triacetate (Triccl) 3 3 (&#39;Terylene&#39;,Acrilan, and &#39;Tricel&#39; are Registered Trade Marks).  
 Table 2 Liquor 1 2 3 4 5 6 7 8 Emulsion A( g) 20 20. 20 20 2O 20 2O 20 Aqueous acetic acid 5% (ml) 4 4 4 4 4 4 4 4 Aqueous hydrogen peroxide 20 vol strength (ml) 15 10 5 2 l Aqueous copper sulphate ml 2.5 Aqueous ferric Chloride 1% (ml) 2.5 Water (ml) 176 161 166 171 I74 175 173.5 173.5 Assessment of iodine staining after (a) washing in water at 60C 2 5 5 5 2-3 2 4 3-4 (b) boiling in hexane l-2 5 5 5 l-2 l-2 3-4 2 EXAMPLE 8 EXAMPLE 1O This Example illustrates that the polyoxypylene triol used to prepare Thiol A had negligible effect on the fibres. Emulsions A and Z were applied to scoured Crimplene fabric at a liquor ratio of 20:1, using thefollowing impregnation liquors.  
 Emulsion A or Emulsion Z Water 20 g 180 ml.  
  The samples treated with Emulsion A were much softer than those treated with Emulsion Z, the handle of which was almost indistinguisable from that of the untreated fabric.  
 EXAMPLE 9 This Example illustrates the enhanced degree of fixation obtained when catalysts for curing Emulsion A are incorporated in the treatment bath. Application Ii- Aqueous liquors containing Emulsions A,C,D,E,F, and G were applied to scoured Crimplene, the liquors containing 1%(on weight of Crimplene) of each of the thiols. The pH of the liquors was adjusted to 3.5 with acetic acid, and treatment was carried out at a liquor ratio of 20:1 for 30 minutes at C. After 15 minutes hydrogen peroxide was added to the liquor so that a 1 volume concentrations resulted. The liquors gradually cleared from their initial white milky appearance. The patterns were spun in a spin dryer without being rinsed, and dried in an oven at 60C for 30 minutes. They were then conditioned overnight in an atmosphere of 66 percent relative humidity and at 20C before assessments of handle were carried out. Thiols E, F and G imparted on extremely soft and pleasant handle to the Crimplene, Thiols A and D gave a very soft handle, while with Thiol C the handle was considerably softer than that of untreated material.  
 EXAMPLE 1 l Thiol A is extremely fast to washing treatments when applied to Crimplene, as shown by the following. Thiol A was applied as in Example 10 to scoured Crimplene, the treated patterns were allowed to condition for 3 days at room temperature and 66 percent relative humidity, and the fastness of the finish was then assessed by washing. The excellent fastness properties of the finish are shown by the fact that there was no difference in handle or in degree of iodine staining between washed and unwashed patterns after the following washing treatments:  
 a. lg/l nonionic detergent b. 2g/l soda ash c. 2g/l soda ash plus 3g/l sodium hydrosulphide.  
  In all cases washings were carried out for minutes at 40, 70, and 100C.  
  The treated patterns were unaffected by simulated perspiration tests at pH 5.5 and 8.0.  
 EXAMPLE l2 In this Example the finish is applied under acidic conditions to obtain optimum exhaustion onto the fibres and then the pH of the liquor is made alkaline to obtain maximum fixation and curing of the thiol.  
  Crimplene was treated at a liquor ratio of 20:1 with a diluted aqueous suspension of Emulsion A (100 g/l) set at pH 4.0 with acetic acid, the fabric being immersed at 60C: during the course of minutes the liquor substantially cleared losing its initial milky-white appearance. The liquor was then adjusted to pH 8.5 or 10.0 by addition of either 3.5 g/l disodium phosphate dodecahydrate 1.5 g/l trisodium phosphate dodecshydrate 2.5 g/l disodium phosphate dodecahydrate 2.5 g/l trisodium phosphate dodecahydrate respectively,  
 EXAMPLE l3 Aqueous liquors containing emulsions A,E, and G-M were applied to a scoured coarse polyester yarn, the liquors containing 1 percent (on the weight of the fibre) of each of the thiols. The pH of the liquors was adjusted to 4.0 with acetic acid and treatment was carried out at a liquor ratio of :1 for 30 minutes at 60C. After 15 minutes, hydrogen peroxide was added to the liquor so that a 1 volume concentration resulted. The liquors, which initially were milky white, gradually cleared. The patterns were spun in a spin dryer and dried in an oven at 60C for 30 minutes. They were then conditional overnight in an atmosphere of 66 percent relative humidity and at 20C. Some patterns were washed in a solution (2 g/l) of a nonionic detergent for 10 minutes at 70C dried, and conditioned as above. Handle assessments were carried out on the conditioned, washed and unwashed patterns and the fastness properties were also assessed by iodine staining. The results are given in Table 3. Handle was assessed according to the following classification:  
 1. Extremely soft and pleasant 2. Very soft 3. Soft 4 Slightly softer than untreated 5. Harsh (untreated) The use of other curing catalysts for the fixation of Emulsion A is illustrated in this example. Emulsion A was diluted with water, and acetic acid was added in some cases. Samples (10 g) of Crimplene fabric were treated with these liquors for 15 minutes at 60C using a liquor ratio of 20:1. The curing catalysts which were solids rapidly dissolved when added to the bath. Treatment was continued for a further 15 minutes under the above conditions, and the fabric samples were then spun in a spin dryer without rinsing and dried in an oven at 55C for 30 minutes. Fixation of the thiol was then assessed by washing the samples in water containing 1 g/l of a nonionic detergent for either 10 minutes at C or 5 minutes at C. Unwashed and washed patterns were stained with iodine and the difference in staining assessed by grey scale measurement. The results are given in Table 4. All of the patterns had a softer and more pleasant handle than had untreated Crimplene.  
  A 50:50 polyester-cotton blend plain weave fabric was padded with one of liquors a, b, or c to 70 percent pick-up, dried at its original dimensions on tenter frames at 60C, and heated for 5 minutes at C. The dry crease angles of the fabric samples were determined by the Monsanto method, 12 speciments (six folded warpwise, six folded weftwise) being used in each test, the specimens were creased under a 2 kg load for 3 minutes and and allowed to hang, suspended over a wire, for 3 minutes before the crease angles were measured. The values given below are the average of the six obtained by adding the warpwise value to the corresponding weftwise value and dividing by two. Tear strengths were determined by the Elmendorf method according to TAPPl Standard T 414 n-49. Three samples, each 63 X 63 mm, were used, and the tear strengths were measured in the warp direction. In  
  19 the following Table, Aminoplast denotes a 50 percent aqueous solution of bis(N-hydroxymethyl) dihydroxyethyleneurea.  
 Table Liquor Untreated a b c Aminoplast (g/litre) 150 150 150 MgCl .6H O (g/litre) 2O 20 20 Emulsion N (g/litre) 30 Emulsion O (g/litre) 30 Grease angle 94 117 122 128 Tear strength (g) 1344 1320 1376 1368 EXAMPLE 16 This Example illustrates that antistatic properties can be imparted by the thiol emulsions. A g piece of scoured Crimplene fabric was treated with a liquor comprising Emulsion A g Aqueous acetic acid (5%) 4 ml Water 176 ml EXAMPLE 17 This Example illustrates that soil-release properties and improved resistance to soil-redeposition can be imparted by the thiol emulsions. Crimplene fabric was treated by the method of Example 15, but was not heatset. Samples of treated and untreated fabric were then screen-printed in a striped pattern with three different soiling compositions, each applied as a band 3 cm wide and separated from the adjoining band by an unsoiled strip of the same width.  
  Soil A is a mixture of used dirty motor oil (50 percent) and petroleum jelly (50 percent).  
  Soil B is a solution of lanolin (84 percent) and trichloroethylene (16 percent).  
  Soil C is a mixture of sieved vacuum cleaner dust (20 percent), lanolin (60 percent), and trichloroethylene (20 percent).  
  The treated patterns were dried in an oven for 2 hours at 35C. Portions of the treated and untreated soiled fabric were then washed for minutes at 40C in a washing machine with a solution of 5 g/l of an anionic detergent.  
 The fabric samples were then dried in an oven at 6 60C and the soil-release and resistance to soil redeposition were noted.  
  The treated sample lost nearly all of each of the soils on washing and there was virtually no soil redeposition on the un-soiled portions of the fabric. The untreated 6 pattern retained a considerable portion of the soil during washing and there was widespread deposition of soil on the un-soiled regions of the fabric.  
  We claim: 1. A process for modifying synthetic fibres which comprises 1. treating the fibres, in the absence of keratinous 5 material, with a polythiol having two to six thiol groups per molecule and a molecular weight between about 400 and about 10,000 wherein the polythiol has the formula r w I I T-(O-alkylene) m OH 20 in which m is a positive integer of at least 1,  
 n is zero of 1,  
 p is a positive integer of at least 2 and at most 6,  
 q is zero or a positive integer of four or less, selected 25 so that (p+q) equals at least 2 and at most 6,  
 each alkylene group contains a chain of at least 2 and at most 6 carbon atoms between consecutive oxygen atoms,  
 R is an aliphatic radical containing at least 2 carbon 0 atoms, and  
 X is an aliphatic radical containing at least one thiol group and 2. curing the polythiol on the fibres.  
  2. The process of claim 1, wherein q is zero or 1,  
 p is 2 to 6, provided that when q is 1, p is 2,  
 R is an aliphatic hydrocarbon radical having at least 3 and at most 6 carbon atoms, and  
  X is an aliphatic radical of the formula C H SI-I,  
 wherein u is 1 or 2.  
  3. The process of claim 1, wherein the polythiol is selected from the group consisting of those of the formu- 5 lae:  
  (1) CH (OC H2 O.CO.C H2 SH (2H2 (OC H O.CO.C H SH JIHZ (OC H O.CO.C H SI-I n (OC H O.CO.C H SH (OC H O.CO.C H SH Continued (IV) CH2 (OC H O.CO.C I-l SH l (2H i- (oc H H (1H i- (OC H O.CO.C H SH CH2 j H (V) CH2 (OC H O.CO.C H SH CH2 .(oc H 0.co.c H sH (v1) CH3CH (OC H O.CO.C H SH CH2 (OC H O.CO.C I-I SH in which a is zero,  
 I is an integer of at least 2 and at most 3, u is a positive integer of at most 2 and m has the meaning given in claim 1.  
  4. The process of claim 3, wherein the polythiol is selected from the group consisting of those of the formula:  
 I, wherein t is 3 and u is 1;  
  III, wherein tis 3 and u is l; and  
  VI, wherein t is 3 and u is 1, said polythiol having an average weight of at least 1,000 and at most 7,500.  
  5. The process of claim 1, wherein n zero and, X is an aliphatic radical of the formula and the alkylene groups are -C H or C H 7. The process of claim 6, wherein R is 01-1,  
 q is zero,  
 p is 3,  
 R is  
 l -CH2CH2CH,  
 the alkylene groups are C l-l and the average molecular weight is between about 700 and about 7,500.  
 and  
  8. The process of claim 1 wherein the polythiol is of the formula CH2 (oc n o.co.c n sn CH (OC H O.CO.C H SH wherein a is 2, t is 4 and u is l, and m has the meaning defined in claim 1.  
  9. The process of claim 1, wherein there is used a weight of polythiol which is 0.1 to 10 percent of the weight of synthetic fibres treated.  
  10. The process of claim 1 in which a catalyst for curing the polythiol is also applied, said catalyst being selected from the group consisting of hoses, siccatives, sulphur, sulphur-containing organic compounds in which the sulphur atoms are not exclusively present as mercaptan groups, free-radical catalysts, salts of heavy metals with acids having an acid strenght (pKl) below 5, and chelates of heavy metals.  
  11. The process of claim 10 wherein the catalyst is hydrogen peroxide.  
  12. The process of claim 1, which comprises treating the synthetic fibres with the polythiol at a temperature in the range of 30 to 220C.  
  13. The process of claim 1, wherein the polythiol is applied to the fibres by immersing them in an aqueous medium which contains the polythiol and which is heated to a temperature in the range 25 to C.  
  14. The process of claim 1, wherein the polythiol is applied to the fibres from an aqueous medium having a pH in the range 3 to 6.  
  15. The process of claim 1, wherein the polythiol is cured at a pH in the range 7.5 to l2.  
  16. The process of claim 1, in which the synthetic fibres are selected from the group comprising fibres of nylon, polyester, polyacrylonitrile, and polyvinyl alcohol.  
  17. Synthetic fibrous material, free from keratinous material, bearing thereon from 0.l to 10 percent by 23 weight of a polythiol resin having 2 to 6 thiol groups per molecule and a molecular weight between about 400 and about 10,000, the polythiol having the formula:  
 i ---(Oalkylene) OH l i (Oalkylene) O(CO) X in which m is a positive integer of at least 1,  
 n is zero or 1,  
 p is a positive integer of at least 2 and at most 6,  
 q is zero or a positive intefer of four or less, selected so that (p+q) equals at least 2 and at most 6,  
 each alkylene group contains a chain of at least 2 and at most 6 carbon atoms between consecutive oxygen atoms,  
 R is an aliphatic radical containing at least 2 carbon atoms, and  
 X is an aliphatic radical containing at least one thiol group.  
 18. The synthetic fibrous material of claim 17,  
 wherein q is zero or 1,  
 p is 2 to 6, provided that when q is l, p is 2 R is an aliphatic hydrocarbon radical having at least 3 and at most 6 carbon atoms, and  
 X is an aliphatic radical of the formula C H SH,  
 wherein u is 1 or 2.  
 19. The synthetic fibrous material of claim 17,  
 wherein the polythiol is selected from the formula:  
  (fl-l (OC H2t) O-CO-C H SI-I (I) (OC H 2 O-CO.C H SI-l CH2 (OC H O.CO.C I-I SH (2H (OC H O.CO.C H SH (EH (OC H CO C H SH II (T 2 CH H CH2- (0CtH t) O-CO-C H uSH (III) (1H (OC H O.CO.C H SH TH (OC H OH CH (OC H O.CO.C H SH (IV) CH (OC H O.CO.C H SH CH 2 H Continued (v) CH (OC H O.CO.C H SH CH and 2 (OC H O.CO.C I-I SH (VI) CH &#39;CH (OC H O.CO.C H SH in which a is zero,  
 I. is an integer of at least 2 and at most 3,  
 u is a positive integer of at most 2 and m has the meaning defined in claim 17.  
  20. The synthetic fibrous material of claim 17, wherein the polythiol is selected from the group consisting of those of the formulae:  
 I, wherein t is 3 and u is 1;  
  III, wherein t is 3 and u is 1; and  
  VI, wherein t is 3 and u is 1, said polythiol having an average molecular weight of at least 1,000 and at most 7,500.  
  21. The synthetic fibrous material of claim 17, wherein n is Zero, X is an aliphatic radical of the formula the alkylene groups are C l-l and the average weight is between about 700 and about 7,500. 24. The synthetic fibrous material of claim 17, wherein the polythiol is of th formula (OC H O.CO.C H SH (OC H O.CO.C H Sl-l wherein a is 2, t is 4 and u is l, and m has the meaning defined in claim 17.