(19)
(11) EP 0 058 138 A2

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication:
18.08.1982 Bulletin 1982/33

(21) Application number: 82810050.3

(22) Date of filing: 05.02.1982
(51) International Patent Classification (IPC)3D06M 15/54
(84) Designated Contracting States:
BE CH DE FR GB IT LI

(30) Priority: 11.02.1981 GB 8104213

(71) Applicant: CIBA-GEIGY AG
4002 Basel (CH)

(72) Inventors:
  • Bellhouse, Eric
    Stockport Cheshire SK6 6PJ (GB)
  • Mosimann, Walter, Dr.
    CH-4106 Therwil (CH)


(56) References cited: : 
   
       


    (54) Process for setting wool yarn


    (57) A process for setting a wool yarn comprising treating the yarn at a temperature within the range from 85° to 108°C and at a pH from 4 to 8, with an aqueous solution containing from 0.5 to 5.0 % by weight, based on the weight of yarn, of an N-methylolurea having the formula

    wherein R is hydrogen, alkyl of 1 to 4 carbon atoms or -CH2OY1; X, and X2 are each hydrogen, alkyl of 1 to 4 carbon atoms or-CH2OY2, or X1 and X2 together represent ethylene, propylene, 1,2-dihydroxyethylene, 2-hydroxypropylene, 1-methoxy-2-dimethylpropylene,



    Y, Y1 and Y2 are each hydrogen or alkyl of 1 to 4 carbon atoms, Z is hydrogen, alkyl or hydroxyalkyl each having 1 to 4 carbon atoms and R' and R" each have the significance given for R.


    Description


    [0001] The present invention relates to a process for setting wool yarn, more particularly to a process for chemically setting hard twist wool yarn.

    [0002] In the carpet industry there is a requirement for improved yarn setting processes for hard twist carpet yarns; the process must be capable of producing and maintaining a high level of twist retention without causing fibre damage.

    [0003] In the present specification and claims, by the term "hard twist wool yarn" is meant a 2-ply or 3-ply yarn in which there is an average degree of twist of from 6 to 12 turns per inch. "Wool yarn" is either 100 % pure wool or a blend of fibres containing wool as the major component e.g. a mixture of wool and polyamide such as an 80:20 % by weight blend of wool and nylon.

    [0004] A known process for setting wool is the so-called hydrosetting method in which yarn is treated in water for 30 to 60 minutes at 70° to 100°C. However, this method has the disadvantages that sufficiently high levels of twist retention are not attained and such hydroset yarns are not sufficiently stable to withstand a subsequent mechanical shampoo treatment - viz. they suffer loss in twist and change in appearance.

    [0005] More recently, there is described in British Patent Specification No. 1393255 a process of setting a hard twist wool yarn by treating it in an aqueous solution with from 0.5 % to 8 % by weight, based on yarn weighty of hexamethylene tetramine (commonly known as hexamine), at pH 5.5 to 8.5 and at 90° to 105°C, until the setting efficiency (defined hereinafter) was at least 70 %.

    [0006] While the latter process is a very successful method of setting wool, we have now found an improved process giving comparable and even higher setting efficiencies while using much less unit weight of active ingredient.

    [0007] According to the present invention, there is provided a process for setting a wool yarn, especially a hard twist wool yarn,at 85° to 108°C, advantageously 85° to 105°C and preferably 95° to 100°C, and at a pH of 4 to 8, comprising treating the yarn with an aqueous solution containing from 0.5 to 5.0 % by weight, based on the weight of yarn, of an N-methylolurea compound having the formula

    wherein

    R is hydrogen, alkyl having 1 to 4 carbon atoms or -CH2OY1;

    X1 and X2 are each hydrogen, alkyl having 1 to 4 carbon atoms or -CH2OY2, or

    X1 and X2 together represent ethylene, propylene, 1,2-dihydroxyethylene, 2-hydroxy-propylene, 1-methoxy-2-dimethylpropylene, -CH2-O-CH2-,

    Y, Y1 and Y2 are each hydrogen or alkyl having 1 to 4 carbon atoms, Z is hydrogen, alkyl or hydroxyalkyl each having 1 to 4 carbon atoms and R' and R" each have the significance given for R.



    [0008] Suitable N-methylolureas are e.g. derivatives of urea, ethylene urea, propylene urea, acetylene diurea or dihydroxyethylene urea, and uron or triazone derivatives.

    [0009] Specific compounds which may be mentioned are:

    N,N'-dimethylolurea, N,N'-dimethylolurea-dimethyl ether, N,N'-tetra- methylolacetylene diurea, N,N'-dimethylolpropylene urea, 4,5-dihydro- xy-N,N'-dimethylolethylene urea, 4,5-dihydroxy-N,N'-dimethylolethylene urea dimethyl ether, N,N'-dimethylol-5-hydroxypropylene urea, 4-methoxy-5,5-dimethyl-N,N'-dimethylolpropylene urea, N,N'-dimethylol-5-oxapropylene urea and, in particular, N,N'-dimethylolethylene urea; and the cyclic urea compounds can in some cases be present also as oligo condensation products.It is also possible to use mixtures of these acyclic and cyclic urea compounds.



    [0010] Alkyl denoted by R, X1, X2, Y, Y1,Y2 and Z in formula (1) is, for example n-butyl, isobutyl, n-propyl, isopropyl or, in particular, ethyl and especially methyl.

    [0011] Especially suitable for the process are N-methylolureas of the

    wherein X3 and X4 each represent hydrogen, alkyl having 1 to 4 carbon atoms or -CH2OY2, or X3 and X4 together represent ethylene, propylene or 1,2-dihydroxyethylene, and R, Y, Y and Y2 have the aforegiven meanings. X3 and X4 together can advantageously also represent 2-hydroxypropylene.

    [0012] Compounds of particular interest are N-methylolureas of the formula

    wherein R1 represents hydrogen, methyl, ethyl, -CH2OH or -CH2OCH3, X5 and X6 each represent hydrogen, methyl, ethyl, -CH2OH, or X and X6 together represent ethylene, 1,2-dihydroxyethylene or 2-hydroxy- propylene, and Y3 represents hydrogen or methyl, with the unetheri- fied N-methylolureas being preferred.

    [0013] Good results are obtained, in particular, with cyclic N-methylolureas of the formula x

    wherein X7 represents hydrogen or hydroxyl, and R2 represents hydrogen or preferably -CH2OH; or are obtained especially with N,N'-dimethylolethylene urea.

    [0014] The N-methylolureas of formula (1) are known compounds which may be produced by methods known per se.

    [0015] The amount of the compound of formula (1) used in the process of the invention is advantageously from 0.6 to 1.25 %,especially from 0.75 to 1.2 % by weight, based on the weight of yarn.

    [0016] The pH value of the treatment medium is preferably from 6 to 8, especially from 7 to 8.

    [0017] The setting process of the invention may be carried out before, during or after the wool yarn to be set has been dyed. It is preferred to carry out the setting of the wool yarn before the dyeing.

    [0018] Conveniently, the process of the invention may be effected by immersing the yarn to be treated in a cold aqueous solution of a compound of formula (1), a convenient liquor ratio being 30:1. The treatment pH is conveniently 7 and the treatment liquor may be heated gradually to the final temperature, desirably the boil, and held at this temperature for e.g. from 10 to 60 minutes. Buffer systems e.g. sodium acetate/acetic acid, monosodium phosphate/ disodium phosphate or sodium acetate may be employed with advantage to maintain pH ranges at preferred levels.

    [0019] Alternatively, the yarn may be padded through a solution of the compound of formula (1) to give a pick-up of approximately 100 % by weight, partially dried e.g. to a moisture content of about 30 % by weight, and then steamed, e.g. for 10 to 30 minutes at atmospheric pressure.

    [0020] The setting may be carried out after dyeing,in which case the same bath may be used for dyeing and setting. It is, therefore, possible to make use of existing single stick yarn dyeing machinery common to all carpet yarn dyehouses. By using coupled dyevats, it is possible to set large weights of yarn in one operation, with consequent advantages in terms of batch uniformity and labour costs.

    [0021] In a further embodiment, the setting may be effected before dyeing in the case of tufted carpets,whereby the carpet containing a pile yarn set according to the process of the invention may be piece dyed.

    [0022] The following Examples further illustrate the present invention in which parts and percentages are by weight.

    [0023] Example 1: An undyed carpet yarn made from a blend of 80 % wool and 20 % polyamide 66 having an original twist of 9.1 turns per inch is treated with 1 % (on the weight of fibre) of N,N'-dimethylolethylene urea for 30 minutes at 100°C. The liquor ratio is 30:1 and the treatment is started cold, the bath being heated at a rate of 2°C/ minute up to the boil. To maintain the pH at 7, a buffer system comprising 5 g/1 monosodium phosphate and 0.5 g/1 disodium phosphate is used.

    [0024] To evaluate the % setting (setting efficiency), five 15 inch lengths of each set hank are relaxed for 24 hours in cold water, air dried and the number of turns per inch(TPI) of a 10 inch sample are measured. The highest and lowest counts are eliminated and an average is calculated from the remaining three counts.



    [0025] For the purposes of comparison, similar experiments are conducted using 1 % hexamine or water, the remaining conditions being the same.

    [0026] The results obtained are set out in the following Table I.



    [0027] Examples 2 to 8: The procedure described in Example 1 is repeated except that the amount of N,N'-dimethylolethylene urea is varied over the range 0.5 % to 2.0 %. The results are set forth in the following Table II.



    [0028] Example 9 and 10: Using the conditions described in Example 1, viz. pH 7 and treatment time of 30 minutes, two different commercial carpet yarn samples are treated with 1 % of dimethylolethylene urea.

    [0029] The setting efficiency is then evaluated using the evaluation method set forth in Example 1.

    [0030] The results obtained are set out in the following Table III which also includes comparative data relating to the known hydroset treatment and to a treatment using 4 % hexamine, the remaining test conditions being as above.



    [0031] Yarn samples I and II are 80/20 woll/polyamide 66 blends, obtained from two commercial sources.

    [0032] The results in Table III show that, even when used at only a quarter of the weight of hexamine, a compound used according to the invention provides a superior setting efficiency on wool/yarn blends.


    Claims

    1. A Process for setting wool yarn comprising treating the yarn at a temperature within the range from 85° to 108°C and at a pH from 4 to 8, with an aqueous solution containing from 0.5 to 5.0 % by weight, based on the weight of yarn, of an N-methylolurea of formula

    wherein R is hydrogen, alkyl having 1 to 4 carbon atoms or -CH2OY1;

    X1 and X2 are each hydrogen, alkyl having 1 to 4 carbon atoms or -CH20Y2, or

    X1 and X2 together represent ethylene, propylene, 1,2-dihydroxyethylene, 2-hydroxypropylene, 1-methoxy-2-dimethylpropylene,

    or

    Y, Y1 and Y2 are each hydrogen or alkyl having 1 to 4 carbon atoms, Z ist hydrogen, alkyl or hydroxyalkyl each having 1 to 4 carbon atoms and R' and R" each have the significance given for R.


     
    2. A process according to claim 1 wherein the wool yarn is a hard twist wool yarn.
     
    3. A process according to claim 1 or 2 wherein the process is effected at a temperature within the range from 95 to 100°C.
     
    4. A process according to anyone of claims 1 to 3, wherein the N-methylolurea has the formula

    wherein

    R is hydrogen, alkyl of 1 to 4 carbon atoms or -CH2OY1

    X3 and X4 each represent hydrogen, alkyl of 1 to 4 carbon atoms, or -CH2OY2, or

    X3 and X4 together represent ethylene, propylene, 1,2-dihydroxyethylene or hydroxypropylene and

    Y, Y1 and Y2 each represent hydrogen or alkyl of 1 to 4 carbon atoms.


     
    5. A process according to claim 4, wherein the N-methylolurea has the formula

    wherein R1 is hydrogen, methyl, ethyl, -CH2OH or -CH2OCH3,

    X5 and X6 are each hydrogen, methyl, ethyl or -CH2OH, or

    X5 and X6 together represent ethylene, 1,2-dihydroxyethylene or 2-hydroxypropylene, and Y is hydrogen or methyl.


     
    6. A process according to claim 5,wherein the N-methylolurea has the formula

    wherein X7 is hydrogen or hydroxyl and R2 is hydrogen or -CH2OH.
     
    7. A process according to claim 6, wherein the N-methylolurea is N,N'-dimethylolethylene urea.
     
    8. A process according to any one of claims 1 to 7, wherein the amount of the N-methylolurea is from 0.6 to 1.25% by weight based on the weight of yarn.
     
    9. A process according to claim 8,wherein the amount of the N-methylolurea is from 0.75 to 1.2 % by weight, based on the weight of yarn.
     
    10. A process according to any one of claims 1 to 9, wherein the pH value of the treatment medium is from 6 to 8.
     
    11. A process according to claim 10 wherein the pH value of the treatment medium is from 7 to 8.
     
    12. Set wool yarn when produced by a process claimed in any one of claims 1 to 11.