A METHOD TO CONTINUOUSLY TREAT WOOL

Abstract: A method for the continuous treatment of a web of wool slivers comprising the following steps separately and in order: (i) continuously treating said web with a non-ionic ethoxylated detergent, (ii) continuously treating said web with permonosulfuric acid or salts thereof, (iii) continuously treating said web with a sulfite containing solution, and (iv) continuously treating said web with an emulsion, dispersion or microemulsion of an aminofunctional polydimethylsiloxane.

Description: A Method to Continuously Treat Wool The present invention relates to a method for the continuous treatment of a web of wool slivers to impart shrink-resistance. In particular, the present invention relates to a shrink resist treatment of wool sliver which avoids chlorination and makes it possible to treat wool webs of wool sliver at high speeds and also to treat wool webs with slivers of weights of 20 ktex or above. An increasing amount of wool is subject to shrink-resist treatments in order to impart machine washability or easy care properties and many such methods have been described. The most common approach to shrink-resist wool involves first subjecting the wool to an oxidative treatment and then to a polymer treatment. This is discussed in detail by K.R. Makinson in "Shrinkproofing of Wool", Marcel Dekker Inc. New York 1979. The most common type of oxidative treatment used to shrink resist wool involves chlorination, either with elemental chlorine as a gas or in aqueous solution, solutions of hypochlorous acid or its salts, or with organic chlorinating agents such as N, N'-dichloroisocyanuric acid or its salts. Bryne et al, Proc. 9 th Intern. Wool Textile Res. Conf. Biella Italy 1995, vol 1, p.234 state that currently more than three quarters of the commercial shrink-resist treatments involve chlorination. In recent years there has been increasing environmental concern about the use of shrink-resist treatments which involve chlorination since during the treatment or in subsequent dyeing or wet treatments chlorinated compounds may be released. The release of such compounds into the environment is restricted in some countries by laws which limit discharges of adsorbable organohalogen compounds (AOX). A further problem with chlorination shrink-resist treatments for wool is the handle of the fabric produced from the wool becomes harsher after the treatment. Methods which impart shrink-resist properties to wool which do not involve chlorination have been developed. The most common of these methods use as an oxidizing agent permonosulfuric acid or its salts (hereafter abbreviated to PMS). Shrink-resistance is not an absolute property. The level of shrink-resistance (usually quantified by determining the amount of change in area or length of a piece of fabric after a defined wash test) will depend on the properties of the wool (mean fibre diameter and length, fibre strength etc.), the construction of the fabric (yarn count, yarn twist, knit or weave structure etc.) and the wash test method (type of washing machine type, duration of test, wash liquor pH, temperature, salt concentration, pass/fail criteria etc.). Shrink resistance is now generally regarded as, and for the purpose of the present invention shrink-resistance is defined, according to the International Wool Secretariat Test Method 31 in which a swatch is knitted from a 2/22 count yarn at a cover factor of 1.1 and relaxed for one ISO 7 A wash cycle followed by 5 ISO 5 A wash cycles in a Wascator front loading machine and shows less than 10% area shrinkage. Hence what may be called shrink-resistance in the older literature may now be regarded as poor shrink-resistance or not shrink-resistant. Different methods of treatment of wool with a chemical such as PMS, result in different effects (eg. amount of reaction, type of reaction, or where on the fibre reaction occurs) and this then influences the shrink-resistance and other properties. Three general types of treatment can be considered - batch, continuous and semi-continuous (or pad/store), and in each type further variations are possible by changing the type of equipment used or the method of operation of the equipment. In a batch treatment the wool is left in a vessel for a period typically from 10 minutes to one hour and the chemicals are added at once or slowly. A feature of batch treatments is the long reaction time which may allow diffusion of small molecules into the fibre. In continuous treatments the wool is rapidly run through a bowl containing a solution of the chemical then after squeezing the wool immediately passes into another bowl or a series of bowls containing water or other chemicals. Such continuous reactions are characterized by short reaction times, typically around 15 seconds and this tends to confine reactions to the fibre surface. The semi-continuous or pad/store method the wool is first passed through a solution of chemicals in the nip of a horizontal pad mangle and then stored for 1 -5 minutes before passing through a series of bowls as in the continuous method. In this approach the reaction time is intermediate between that of continuous and batch treatments. In the semi-continuous method during storage if the reaction is exothermic the temperature will rise, unlike the continuous method where the large volume of solution in the bowl keeps the temperature constant, or the batch method where the temperature can be varied as desired. Another variant in the continuous method concerns the design of the bowls; in early equipment, backwashing bowls were used in which the web of wool is conducted around a series of solid rollers submerged in the treatment solution, whereas in modern suction drum bowls the web is passed around the outer surface of a perforated drum and the solution is sucked by means of a pump continuously through the web into the drum and then returned to the bowl. In suction drum bowls the pumping action ensures 5 an even treatment throughout the web of wool, whereas in backwashing bowls the outer surfaces of the web may undergo a greater extent of chemical reaction than the centre of the web. Further control can be effected on the extent of reaction and the treatment process, for example in the continuous method the speed at which the wool is transported through the bowls may be varied or the rate at which liquid is pumped through the web in suction drum bowls may be varied. 10 PMS is known to impart shrink-resistance to wool, eg. British Patents 692,258, 716,806 and 1,084,716 which describe batch, pad/store or continuous treatments with backwashing bowls, however the level of shrink resistance was low. D.L. Connell in Deutschen Wollforschungsinstitutes Reports, Nol 114, 1995, page 183 provides an example of the low 15 shrink-resistance from a commercial continuous (pad/store) PMS treatment known as Dylan XCP. The level of shrink-resistance was improved by a subsequent treatment with another oxidizing agent such as a chlorinating agents (British Patents 1,073,441, and 1, 118,792) or permanganate (British Patents 872,292 and 991,163, and Byrne et al. vide supra) or hydrogen peroxide (British Patent 1,071,053). In PCT application WO 92/00412 wool is simultaneously 20 treated with PMS and hydrogen peroxide by a pad store method. PCT application WO 92/00412, also describes the addition of polymers to further enhance the shrink-resistance. Polymers suitable for use in enhancing shrink resistance have been described as containing amino groups and having a backbone comprising carbon atoms, some of which may be replaced by nitrogen or oxygen atoms (eg. US Patent 3,811,835, European patents 414,377 and 315,477). 25 However such polyamine treatments produce a harsh handle or create dyeing problems. PCT application WO 93/13260 describes the simultaneous treatment of wool with three components - PMS, a wetting/scouring agent and a swelling /dispersing agent; this patent describes batch treatments and claims continuous treatments but these are not demonstrated in the examples. In a paper presented and published in the Deutschen Wollforschungsinstitutes Schriftenreihe, 30 1991, vol. 108 page 627 G.B. Guise described a continuous (suction drum) PMS wool treatment at 5 metres/min which gave a high level of shrink-resistance. D.L. Connell in Deutschen Wollforschungsinstitutes Reports, 1995, Nol. 114, page 183 describes an improved continuous PMS treatment to shrink-resist wool. P. Schϋrek et al. in Proc. 9 th Intern. Wool Textile Res. Conf Biella Italy 1995, vol 1, page 199 describe a continuous PMS shrink-resist treatment. The treatment of wool with PMS by different methods will produce different effects, different levels of shrink-resistance or other differences in the properties of the treated wool and it is generally not possible to predict from the results of one method of treatment to the results of another method. We have now found that continuous treatment of wool slivers with PMS in a sequence of processing steps permits higher processing rates and surprisingly improved properties in the wool when compared with batch PMS treatments of the prior art, or from semi-continuous pad/store PMS treatments of the prior art. According to the present invention there is provided a method for the continuous treatment of a web of wool slivers comprising the following steps separately and in order: (i) continuously treating said web with a non-ionic ethoxylated detergent, (ii) continuously treating said web with permonosulfuric acid or salts thereof, (iii) continuously treating said web with a sulfite containing solution, and (iv) continuously treating said web with an emulsion, dispersion or microemulsion of an aminofunctional polydimethylsiloxane. In the following discussion (i), (ii), (iii) and (iv) are referred to as stages (i), (ii), (iii) and (iv) respectively. Surprisingly found that this particular treatment sequence imparted a high level of shrink- resistance (as defined above), was able to impart such shrink-resistance to fine wools. In contrast it was found that continuous PMS treatments of the prior art did not impart such a high level of shrink-resistance or could only do so if operated at a much lower speed and with much lighter slivers, or were not applicable to wools as fine as 18 micron average fibre diameter. It is well known that fine wools (eg. 18 micron average fibre diameter) are more difficult to shrink- resist than coarse wools (see K.R. Makinson vide supra). A particular advantage of the present invention is the ability to treat a web of wool slivers with weights greater than 30 ktex and fibre diameters greater than 18 micron, at a speed in excess of 8 metres/min. We have found that it is necessary for each of the four stages designated (i), (ii),(iii) and (iv) to be carried out sequentially in order to obtain the improvement in shrink resistance. If one or more of the stages was omitted, the shrink resistance was found to fall significantly. The wool for the purposes of the present invention may be in the form of slivers which may or may not have been combed. In other words, the method is applicable to card sliver as well as to tops. Slivers subjected to continuous treatments typically have a weight above 15 ktex. We have found that it was also possible to treat slivers in accordance with the present invention of 30 ktex or in excess such as 40 ktex and still obtain a high level of shrink-resistance. In prior art processes such as in continuous industrial PMS and chlorination treatments for wool, slivers of around 20 ktex are commonly used and it is well known with chlorination treatments that heavier slivers particularly above 30 ktex, obtain uneven treatment and the shrink-resistance is poor. The ability to treat slivers in accordance with the present invention of 30 ktex or higher, such as 40 ktex, substantially increases productivity. The method of the present invention may be carried out in any apparatus suitable for continuously processing a web of wool slivers such that the web is capable of treatment with a solution. We have found that it is preferred to continuously treat a web of wool slivers in a series of suction drum bowls. Other types of apparatus, such as immersion bowls or by conveying the web through bowls or under sprays between two continuous perforated belts, may be used but are not as effective at imparting shrink resistance as suction drum bowls. The residence time of each of the four stages designated (i), (ii), (iii) and (iv) are from about 10 to about 20 seconds, preferably about 15 seconds. For example, in a suction drum having a diameter of about 500 millimetres, which for a 1 metre wide drum would typically be in a bowl of volume between 400 and 600 L and solution would be pumped through the drum at a rate of about 2-4 bowl volumes/minute, typically 3. These residence times correspond to all web speeds of in excess of 8 metres per minute. Typically when a series of suction drum bowls are operated in practice the bowls will not all operate at the same speed. Usually the first bowl is slightly slower than the second which in turn operates at a slightly slower speed than the third and so. The reason for this is that the wet web tends to draft slightly, i.e., the web extends and the weight per unit length is slightly reduced. Consequently when a speed of say 8 metres/minute is quoted this speed refers to the speed of the wool web as it passes out of the last bowl. Advantageously, the present invention makes it possible to operate at speeds hithertofore unattainable of 8 metres/minute or greater, and particularly in the range 10-12 metres/minute and still impart a high level of shrink- resistance. The ability to treat wool webs at 10 m/minute or greater speeds under industrial conditions substantially increases productivity compared with methods of the prior art which operate at slower speeds. This contrasts with prior art continuous PMS treatments in which it is necessary to treat at slow speeds. Preferably a series of suction drum bowls are operated so that, as the wool web leaves each suction drum bowl the web passes through a series of squeeze rollers to prevent excess liquid being removed from the bowl and the liquid removed from the web by the squeeze rollers is allowed to flow back into the suction drum bowl. We have found that in order to produce a uniform treatment over a period of time, it is desirable to maintain concentrations in the various bowls as close as possible to a constant value and this requires the constant addition of reagents to replace that removed by reaction with or deposition onto the wool, and that carried out on the wool into the next bowl as entrained solution. Hence in the following discussion the preferred conditions of the present invention have been defined in terms of steady state suction drum bowl concentrations, rather than as treatment levels (usually expressed as a percentage on the weight of wool). These concentrations have been given as ranges and will vary with treatment speeds and wool types, particularly average fibre diameter. The addition rates required to maintain constant concentrations will be readily determined by simple experimentation so as to compensate for variations in treatment solution concentrations. It is well know that untreated wool only slowly wets out when placed in water and this has been attributed to the presence of a lipid layer on the surface of the wool fibres. Hence it is a well established practice to add wetting agents in the first stage of wool treatments. Such wetting agents are particularly important in continuous treatments because there is only a short time available for reaction; for example if a dry wool sliver is run into a PMS solution as described in the prior art in a suction drum bowl operating from 5 to 15 metres/minute the treatment will be uneven since the centres of slivers will not have wet out completely during immersion. Consequently in continuous PMS treatments it is usual practice to add a wetting agent, to the PMS treatment solution. We have unexpectedly found that if replacing a continuous treatment with a mixture of PMS and wetting agent with stages (i) and (ii), the shrink-resistance imparted was surprisingly improved. The method of the present invention, provides surprising improvements, even over continuous treatments employing PMS and high levels, such as 5-10 g/L, of wetting agent. We have found that the amount of non-ionic ethoxylated detergent used in stage (i) will be dependent upon the web if wool slivers, the type of non-ionic ethoxylated detergent, and the residence time of the wool slivers in the detergent solution. Preferably the concentration of non- ionic ethoxylated detergent in stage (i) is in the range of from 4-10 g/L, more preferably 5 g/L. The temperature of stage (i) is preferably in the range of from 40-70 °C, more preferably 50 °C. The non-ionic ethoxylated detergent may be any such detergent which is used as a standard scouring agent in the industry. The non-ionic ethoxylated detergent is preferably an alkylene oxide, more preferably an ethylene oxide, derivative of a fatty alcohol or an alkylphenol. Preferred detergents are derivatives of fatty alcohols having from ten to twenty carbon atoms or mixtures thereof or alkylphenols with alkyl groups having from seven to twelve carbon atoms reacted with from five to fifteen moles of ethylene oxide. The preferred method, for use in stage (i) includes suction drum bowls but may also include other types of apparatus, including the Fleissner split-pad chlorinator, and the Kroy deep irnmersion chlorinator which are used commercially in continuous chlorination shrink-resist treatments for wool. These types of apparatus are readily adapted for treatment of the web with non-ionic ethoxylated detergents. It will be appreciated that if a dry web of wool enters stage (i) such as into a suction drum bowl, containing the non-ionic ethoxylated detergent and a wet web leaves the bowl, the volume of liquid in the bowl will decrease with time. Additionally dirt and grease will build up in the bowl. It is preferred to add the non-ionic ethoxylated detergent solution to the bowl, and preferably the rate of addition of detergent solution is in the range of from 2 to 10 times, the weight of the dry wool web entering the bowl in that given time most preferably from 5 to 8 times. The permonosulfuric acid or salts thereof is preferably in aqueous solution obtained by dissolving the triple salt 2KHSO 5 .KHSO 4 .K 2 SO 4 in water; this triple salt is available commercially as Caroat (Degussa) or Oxone (DuPont). It is to be appreciated by those skilled in the art that solutions of the PMS triple salt could be replaced by solutions containing equivalent concentrations of pure permonosulfuric acid, or by solutions of the sodium salt of permonosulfuric acid adjusted to pH 2 with sulfuric acid. The permonosulfonic acid may also conveniently be produced by the reaction of hydrogen peroxide with sulfuric acid. The preferred method of the present invention in the second suction drum bowl uses a solution of the permonosulfuric acid or salts thereof at a concentration preferably in the range of from 20 to 60 g/L in water at a temperature preferably in the range of from 20 to 60 °C. In a more preferred method of the present invention two separate suction drum bowls containing the solution of permonosulfuric acid or salts thereof are used in stage (ii). The sulfite solution used in stage (iii) is preferably a solution of sodium sulfite at a concentration from 20-50 g/L and at a temperature from 20-50 °C. The sulfite solution is preferably maintained at a pH in the range 8-10, such as by the addition of sodium carbonate or sodium hydroxide. It is to be appreciated by those skilled in the art that the sulfite solution could be prepared potassium sulfite or that solutions of sodium bisulfite, sodium metabisulfite or sulfur dioxide adjusted to pH 8-10 with alkali. The aminofunctional polydimethylsiloxones for use in the present invention may have a linear or branched backbone and the aminofunctional groups may grouped together in blocks or randomly distributed along the polydimethylsiloxane backbone. The aminofunctional groups are preferably in the separated from the silicon atoms of the backbone by three or more carbon atoms and may be primary, secondary or tertiary aliphatic amines or a mixture thereof. Examples of suitable commercially available aminofunctional polydimethylsiloxanes include SM 8709 (Toray Dow-Corning) CT 45e and NP 1445e (Wacker Chemie), and JG4008A and AR4136A (Flexichem). The arninofunctional polydimethyl siloxane may be in the form of an emulsion, dispersion or microemulsion, conveniently prepared with the aid of cationic, non-ionic or anionic emulsifiers, preferably at a concentration in the range of from 2 to 20 g/L of the aminofunctional polydimethyl siloxane and more preferably in the range of from 5 to 15 g/L. Preferably the pH is maintained in the range of from 4 to 7. Other materials known to influence textile properties, other than shrink-resistance, may conveniently be added in stage (iv) with the aminofunctional polydimethylsiloxane such as lubricants (to improve subsequent gilling, combing, drawing and spinning performance) antistatic agents, fungicides, bactericide, moth-proofing agents and softening agents such long chain quaternary ammonium surfactants. The use of such materials is well known to those skilled in the textile art. It is to be appreciated that if such materials are added at stage (iv) the material should not contain any strongly anionic components as this may cause the cationic aminofunctional polydimethylsiloxane emulsion to become unstable. Several modifications of the present invention are possible. It has been found that it is possible to place additional suction drums bowls in order to repeat the processing steps recited above to obtain desired residence time in treatment solutions. Advantageously additional steps to rinse the wool with water may be used. For example, rinse bowls can be placed between stages (i) and (ii) between stages (ii) and (iii) or between stages (iii) and (iv), and this may conveniently be done with any combination of between one and three rinse bowls. It is to be appreciated that after treatment of wool in a series of aqueous solutions it is necessary to dry the wool before it can be processed further. Typically the wool is passed around the surface of perforated cylindrical drums through which hot air is drawn. Two stage dryers may also be used and between the stages of the two dryer stages it is possible to place a suction drum bowl. It has been found that stage (iv) of the present invention can be performed in a suction drum between the two stages of the dryer. In other words the wool can be dried between stages (iii) and (iv). Two stage dryers allows another variant of present invention that the other materials that can be applied in stage (iv) may be sprayed onto the wool between the dryer stages. Wool treated by the methods of the prevention was found to have a high level of shrink- resistance as measured according to IWS TM31 and discussed above, to have a soft handle, to have a whiter colour than the untreated wool, to dye in a similar manner to untreated wool (unlike wool treated with commercial cationic polymers such as Hercosett 250 (Hercules Inc.), to dye under pressure in top form without hardening, to dye such that the dyed wool has good rub-fastness, and had a reduced tendency to form pills. From the environmental point of view the methods of the present invention do not release AOX either during the treatment or in subsequent dyeing or finishing. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. The following examples are provided to illustrate the present invention and in no way intended to be limiting. Wash Testing: A sample of treated wool sliver was spun to a 2/71 tex yarn with 370 tpm singles and 213 tpm twofold twist which was knitted into a single jersey swatch with cover factor 1.1. Swatches were washed in a Wascator FOM 7 IMP machine according to the International Wool Secretariat Test Method 31. A 1 kg load of samples and polyester weighting squares are relaxed by washing with one 7 A wash cycle, measured washed for five 5 A wash cycles, measured again and the area shrinkage (abbreviated below to AS) is then calculated. An area shrinkage in excess of 10% is considered a failure (and is shown as F in the results below). The following chemicals were used in the examples below: A Alcopol 650 (Allied Colloids) a non-ionic ethoxylate B Synperonic 10/6 (ICI) a C 13 -C 15 alcohol ethoxylate with an average of 6 moles +of ethylene oxides per alcohol C Lissapol 91/6 (ICI Australia) a C 9 -C,, alcohol ethoxylate with an average of 6 moles of ethylene oxides per alcohol D Lissapol TN450 (ICI Australia) a nonylphenol ethoxylate E Oxone (DuPont) the triple salt F Anhydrous sodium sulfite G Selbana 4611 (Henkel) a wool processing and spinning lubricant H Wacker CT 45e (Wacker Chemie) an aminofunctional polydimethylsiloxane J SM 8709 (Toray Dow-Corning) an aminofunctional polydimethylsiloxane K Hercosett 250 (Hercules Inc.) the product from the reaction of epichlorohydrin with an amino-functional polyamide L JG4008A (Flexichem) aminofuncitonal polydimethylsiloxane M AR 4136 A (Flexichem) aminofuncitonal polydimethylsiloxane Example 1 A web of wool 36 slivers of weight 20 ktex from a combed wool top 21 microns mean fibre diameter, 70 mm mean fibre length, pH 8-9 , was treated at a speed of 10 metres/min in an industrial plant with series of 6 suction drum bowls 1 m wide with a volume of 500 L and perforated drums 300 mm in diameter, each bowl being separated from the next by hydraulically operated squeeze rollers set to give a 50% expression, and then passed into a 5 drum dryer. In each experiment (i) addition of chemicals were made to bowls 2, 3,4, and 6 so as to maintain the concentrations listed in the following table, (ii) the temperatures were maintained at the values shown in the table by thermostatically operated heating coils, (iii) in bowl 1 a the starting solution was added at the rate of 6 L per kg of dry wool entering the bowl, (iv) bowl 4 was maintained at pH 9.5 by the addition of 10% sodium carbonate solution, and (vi) bowl 6 was maintained at pH 5.5 by the addition of 10% acetic acid solution. Experiments 1-4 demonstrate that the methods of the present invention are superior to those in which the wetting agent is not in a separate bowl at the start but is omitted or is added to the PMS bowl. Experiments 5-7 demonstrate the importance of the preferred conditions in the pre- scour stage 1, while experiments 16-18 demonstrate the use of alternative non-ionic detergents in stage (i). Experiments 8-1 1 demonstrate the shrink-resistance is lost one of the PMS bowls, the sulfite bowl or the silicone is omitted. Experiments 12-14 demonstrate that the omission of the lubricant Selbana 4611 has no effect and that another silicone can be used. In experiment 15 the polymer Hercosett 250, which is extensively used on chlorinated wools, gives no shrink- resistance. Example 2 This example uses the same conditions as experiment 1 of Example 1 but wools of different average fibre diameters and/or sliver weights were treated at different line speeds. Example 3 This example uses a two stage dryer rather than the one stage dryer used in example 1. Between the two stages there is an additional suction drum bowl designated bowl 7. In the following experiments bowls 1 to 5 inclusive were the same as in experiment 1 example 1. This example demonstrates that it is possible to dry the wool before the silicone is applied. Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications which fall within its spirit and scope. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

Claims: CLAHVIS 1. A method for the continuous treatment of a web of wool slivers comprising the following steps separately and in order: (i) continuously treating said web with a non-ionic ethoxylated detergent, (ii) continuously treating said web with permonosulfuric acid or salts thereof, (iii) continuously treating said web with a sulfite containing solution, and (iv) continuously treating said web with an emulsion, dispersion or microemulsion of an aminofunctional polydimethylsiloxane. 2. A process according to claim 1 wherein each of the four stages designated (i), (ii), (iii) and (iv) is performed in one or more suction drum bowls. 3. A process according to claim 1 wherein the residence time of each of the four stages designated (i), (ii), (iii) and (iv) are from about 10 to about 20 seconds. 4. A process according to claim 1 wherein the web of wool slivers is continuously treated at a rate in excess of 8 metres per minute. 5. A process according to claim 1 wherein the web of wool slivers is continuously treated at a rate in the range of from 10 to 12 metres per minute. 6. A process according to claim 1 wherein the concentration of treating agents used in stages (i), (ii), (iii), and (iv) are maintained in steady state by the continuous addition of treatment agents. 7. A process according to claim 1 wherein the non-ionic ethoxylated detergent is an alklyene oxide derivative of a fatty alcohol or an alkylphenol. 8. A process according to claim 7 wherein the derivative of the fatty alcohol has from ten to twenty carbon atoms or mixtures thereof or the derivative of the alkylphenol comprises alkyl groups having from seven to twelve carbon atoms reacted with from five to fifteen moles of ethylene oxide. 9. A process according to claim 1 wherein the permonosulfuric acid or salts thereof is in aqueous solution. 10. A process according to claim 9 wherein the aqueous solution is obtained by dissolving the triple salt 2KHSO 5 .KHSO 4 .K 2 SO 4 in water, a solution of pure permonosulfuric acid, or by solutions of the sodium salt of permonosulfuric acid adjusted to pH 2 with sulfuric acid, or produced by the reaction of hydrogen peroxide with sulfuric acid. 11. A process according to claim 9 wherein the solution of the permonosulfuric acid or salts thereof at a concentration preferably in the range of from 20 to 60 g/L in water at a temperature preferably in the range of from 20 to 60 °C. 12. A process according to claim 1 wherein sulfite solution is selected from the group consisting of a solution of sodium sulfite, a solution of potassium sulfite, or solutions of sodium bisulfite, sodium metabisulfite or sulfur dioxide adjusted to pH 8-10 with alkali. 13. A process according to claim 1 wherein the sulfite solution comprises sodium sulfite. 14. A process according to claim 1 wherein the aminofunctional polydimethylsiloxones comprises linear or branched backbone and the aminofunctional groups may grouped together in blocks or randomly distributed along the polydimethylsiloxane backbone. 15. A process according to claim 1 wherein the aminofunctional polydimethylsiloxane is at a concentration in the range of from 2 to 20 g/L. 16. A process according to claim 1 wherein the aminofunctional polydimethylsiloxane is in the range of from 5 to 15 g/L. 17. A process according to claim 1 wherein the aminofunctional polydimethylsiloxane is maintained at a pH in the range of from 4 to 7. 18. A web of wool slivers treated by the process according to claim 1. 19. Shrink resistant wool treated by the process according to claim 1.

Inventors: DENNING RON, FREELAND GRAEME, GUISE BRUCE, DENNING, RON, FREELAND, GRAEME, GUISE, BRUCE
Applicants: COMMW SCIENT IND RES ORG, DENNING RON, FREELAND GRAEME, GUISE BRUCE, COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION, DENNING, RON, FREELAND, GRAEME, GUISE, BRUCE
Application year: 1998
Main classification: D06M11
IPC codes: D06L3, D06M11, D06M13, D06M15