The present invention relates to a woven fabric, more particularly to a woven fabric which is stretchable and contains elastic polyurethane yarns, and to a clothing product such as jeans using the same.

Woven fabrics of cotton have been widely used to jeans and the like. Jeans are sometimes subjected to finishing for giving old appearance and texture after a fabric dyed with indigo is subjected to sewing in order to enhance fashionability thereof. Specifically, the finishing includes a stonewash finish using pumice or abrasives for washing, bleaching using an oxidizing agent such as sodium hypochlorite for decoloration, and the like.

In recent years, since stretchability of fabric is often required of woven products, a woven fabric which is given stretchability by mixing an elastic fiber is proposed. For example, a woven fabric containing a yarn with a staple fiber of cotton, rayon or the like wound on an elastic polyurethane fiber (core-spun yam, hereinafter referred to as CSY) has characteristics excellent in stretchability (refer to Patent Document 1).

However, the stretch woven fabric comprising such an elastic polyurethane yarn has suffered from the problem of reduction in the stretchability thereof after bleaching since the elastic polyurethane yarn contained therein has poor chemical resistance in the bleaching.

Patent Document 2 has proposed a bleached stretch fabric comprising an elastic polyurethane yarn prepared by using a polyester diol which is said to have excellent anti-chlorine performance. However, such an elastic polyurethane yarn is poor in elastic recovery performance of elongation. Moreover, in recent years, more intensive bleaching has been attempted for the purpose of enhancing fashionability. When the elastic ester-based polyurethane yarn was subjected to such bleaching, it was made brittle, leading to unfavorable reduction in stretchability.

On the other hand, woven fabrics comprising polytrimethylene terephthalate yarn are proposed (refer to Patent Documents 3 and 4) as examples in which elastic yarns other than polyurethane are used. However, these woven fabrics have poorer stretch performance than that of a fabric prepared by using an elastic polyurethane yarn.

• [Patent Document 1] JP-A-2003-113549
• [Patent Document 2] JP-A-04-185737
• [Patent Document 3] JP-A-2003-147661
• [Patent Document 4] JP-A-2003-301350

It is a subject of the present invention to provide a bleachable stretch woven fabric which has solved the conventional problems as described above and is excellent in stretchability even after bleaching, and to provide a woven product obtained by using the same.

In order to solve the above described subject, the inventors have found the following constituent features and accomplished the present invention.

The present invention is configured as follow:

1. (1) A stretch woven fabric characterized by comprising an elastic polyurethane fiber(s) containing two or more metals selected from Mg, Al and Zn in part of a yarn.

• (2) The stretch woven fabric according to the above (1), wherein the content of the metal elements in the elastic polyurethane fiber is from 0.5 to 10%.

• (3) The stretch woven fabric according to the above (1) or (2), wherein the fabric contains a composite oxide or a composite hydroxide of the two or more metals.

• (4) The stretch woven fabric according to the above (3), characterized in that the metal composite hydroxide is a hydrotalcite represented by the formula (I):
  
  
  
          M²⁺ _xAl₂(OH)_2x+6-nz(A^n-)_z·mH₂O     (I)
  
  
  
  wherein M²⁺ is Zn or Mg, A^n- is an n-valent anion such as OH^-, F^-, Cl^-, Br^-, NO₃ ^-, CO₃ ^2-, SO₄ ^2-, Fe(CN)₆ ^3-, CH₃COO^-, an oxalate ion and a salicylate ion, n is the valency of the anion, x>0, 0<z≤2, and m≥0.

• (5) The stretch woven fabric according to the above (3), characterized in that the metal composite oxide is a compound represented by the formula (II):
  
  
  
          (x-1)ZnO·ZnAl₂O₄     (II)
  
  
  
  wherein x is a positive numeral of 2 or more.

• (6) The stretch woven fabric according to any of the above (1) to (5), characterized in that the fabric is a twill fabric.

• (7) A stretch woven product obtained by using a stretch woven fabric according to any of (1) to (6).

• (8) The stretch woven product according to the above (7), characterized in that the product is bleached.

• (9) Use of a stretch woven fabric according to any of (1) to (6) for a bleached stretch denim product.

The stretch woven fabric of the present invention has excellent stretch performance even after bleaching, excellent chemical resistance, and good bleachability.

The present invention will be specifically described below.

The stretch woven fabric of the present invention is a woven fabric mainly consisting of cotton and an elastic polyurethane fiber and is characterized by having stretchability. An elongation percentage and an elastic recovery percentage of elongation can be cited as the indices of stretchability of a fabric. The stretch woven fabric of the present invention preferably has an elongation percentage in the weft direction of 5% or more, more preferably 10% or more, and most preferably 15% or more and 40% or less. The stretch woven fabric having stretchability in both the warp and weft directions is particularly preferred.

The stretch woven fabric of the present invention is characterized by comprising an elastic polyurethane fiber. The elastic polyurethane fiber may be woven as a yarn without further processing (used as a bare yam), but it is preferred that the elastic polyurethane fiber is used as a composite with another fiber in terms of durability, texture and the like. The other composite member includes natural fibers such as cotton and hemp, regenerated cellulosic fibers such as viscose rayon, cuprammonium rayon (product name: Cupra) and specific cellulose (trade name: Tencel), and synthetic fibers such as polyester fiber and polyamide fiber. The resulting composites include paralleled yam, air covered yam, covered yam, doubly twisted yam, core-spun yarn in which a sheath yarn is wound on an elastic polyurethane fiber as a core yam, and the like, according to the process of making an individual composite. Among others, a core-spun yarn in which the sheath yarn is a staple spun yarn is preferred.

The content of the elastic polyurethane fiber in a woven fabric is not particularly limited as long as the fiber can impart required stretchability, but the content is preferably from 2 to 40% in terms of covering and elastic recovery of the elastic yarn.

The elastic polyurethane fiber used in the present invention can be obtained from a polymer diol having hydroxy groups at both molecular ends and a number average molecular weight of 600 to 5,000, an organic diisocyanate, and a polyfunctional active hydrogen-containing compound.

Various diols such as polyester diols and polyether diols can be used as the polymer diol. A polyether-based elastic polyurethane fiber using a polyalkylene ether glycol is preferred because it is excellent in stretch performance and weathering performance. As the polyalkylene ether diol, a homopolymer such as polyoxyethylene glycol, polyoxypropylene glycol, or polytetramethylene ether diol (PTMG) may be used as well as a copolymer diol also containing a 2,2-dimethylpropylene group, a 3-methyltetramethylene group, or the like. PTMG or copolyether glycol comprising a tetramethylene group and a 2,2-dimethylpropylene group is suitable, and it preferably has a number average molecular weight of 500 to 5,000, more preferably 1,000 to 3,000.

The organic diisocyanates include known aliphatic, alicyclic and aromatic isocyanates, and the like. Preferred is 4,4'-diphenylmethane diisocyanate.

As the polyfunctional active hydrogen-containing compounds, various low molecular weight diols and low molecular weight amines can be used singly or in combination. Ethylenediamine is preferred.

The elastic polyurethane fiber in the stretch woven fabric of the present invention is characterized by containing two or more metals selected from Mg, Al and Zn. It is possible to ensure the stretch performance of a fabric without reduction in the tenacity and elastic performance of a fiber even after the bleaching described below by introducing a plurality of metals as described above. It is preferred that the fiber contain two types of metals, Mg and Al, in terms of chlorine resistance.

For introducing two or more metals as described above, the fiber may contain a plurality of oxides or hydroxides of Mg, Al, and Zn, but it is preferred that the fiber contain a composite oxide or a composite hydroxide of Al with Mg or Zn. Examples of these compounds include hydrotalcite compounds, composite oxides obtained by firing the same, or the like. Particularly preferred is a hydrotalcite compound having a structure represented by the formula (III):

        M²⁺XAl₂(OH)_2x+6-nz(A^n-)_z·mH₂O     (III)



wherein M²⁺ is Zn or Mg, A^n- is an n-valent anion such as OH^-, F^-, Cl^-, Br^-, NO₃ ^-, CO₃ ^2-, SO₄ ^2-, Fe(CN)₆ ^3-, CH₃COO^-, an oxalate ion and a salicylate ion, n is the valency of the anion, x>0, 0<z≤2, and m≥0.

The composite oxide of A1 with Mg or Zn is preferably obtained by firing the above hydrotalcite, and particularly preferred is the one having a structure represented by the formula (IV):

        (x-1)ZnO·ZnAl₂O₄     (IV)



wherein x is a positive numeral of 2 or more.

These compounds can be added to a polyurethane polymer solution before spinning in a dispersed state. The content of the metal elements (sum of Mg, Al, and Zn) in the elastic polyurethane fiber is preferably from 0.5 to 10% by weight. The metal compounds give an insufficient chlorine resistance when the content is less than 0.5% by weight, and they not only exert adverse effects on the physical properties of the fiber but also increase yarn breakage during spinning when the content exceeds 10% by weight. A more preferred content is from 2 to 8% by weight.

The stretch woven fabric of the present invention is not limited to the weave as long as it is a fabric, but it is preferably a twill fabric in order to be used for stretch denim products. As a warp yarn are used natural fibers such as cotton and hemp, regenerated cellulosic fibers such as viscose rayon, cuprammonium rayon (trade name: "Bemberg") and specific cellulose (trade name: "Tencel"), and synthetic fibers such as polyester fiber, polyamide fiber and elastic polyurethane fiber. Staple fibers, composite spun yarn with the fibers as described above, and the like can be used as the warp yarn. Colored yarn thereof may also be used. The yarn as described above may be used singly or as a composite yarn with polyurethane. Warp yarns may be arranged.

A weft yarn may contain a bare yarn of an elastic polyurethane fiber or a composite yarn (such as CSY) or may be arranged with a yarn containing no elastic polyurethane yarn.

The stretch woven fabric or the present invention may be a 2-way woven fabric (woven fabric stretchable in both the warp and weft directions) containing the elastic polyurethane fiber in both the warp and weft yarns or may be a 1-way woven fabric (woven fabric stretchable in one direction) containing the elastic polyurethane fiber either only in the warp yarn or in the weft yarn. Preferably, the woven fabric contains the elastic polyurethane fiber in at least the weft direction as described above for providing stretchability in the weft direction.

The size of a yarn may be optionally selected depending on the performance required for a woven fabric and a product to be obtained.

The stretch woven fabric of the present invention has an effect that it has good stretch performance after bleaching.

The bleaching includes a treatment of bleaching a fabric or a fabric product using an oxidizing agent based on chlorine, bromine, or the like. Sodium hypochlorite is preferably used as the oxidizing agent. Conditions such as treatment concentration, temperature and time may be conventional conditions, for example, an available chlorine amount of from 0.01 to 2%, a temperature of from 0 to 70°C, preferably from room temperature to 60°C, and a treatment time of from 1 to 60 minutes, preferably from 5 to 40 minutes.

The stretch woven fabric of the present invention can have high stretchability such as an elongation percentage in the weft direction of 5% or more, an instantaneous elastic recovery percentage after bleaching of 70% or more, and an elastic recovery percentage after bleaching of 75% or more. Accordingly, it can be suitably used for stretch woven products such as jeans and the like.

The stretch woven fabric of the present invention as described above can have high stretchability such as an instantaneous elastic recovery percentage of 70% or more and an elastic recovery percentage of 75% or more, in particular, even after it is subjected to a strong bleaching condition, for example, a treatment time of 20 to 60 minutes, which has been employed recently for the purpose of enhancing fashionability.

The present invention will be specifically described with reference to examples. However, the present invention is not limited thereto.

Measurement methods and evaluation methods in the present invention will be described below.

An elastic polyurethane fiber is pulled-out from a fabric as a sample. About 5 g of the sample is treated and then measured for the content of metal elements, Mg, A1 and Zn, by X-ray fluorescence analysis.

The measurement is performed as described below in accordance with a method B: constant-load method of JIS-L-1096.

A fabric piece of 5 cm x 30 cm is collected from a fabric as a test piece, fixed at one end thereof with an upper clamp, applied at the other end thereof with an initial load (20 g), then provided with two marks with a spacing of 20 cm (L0), applied with a load of 1.5 kg gently, and measured for the length between the two marks after being left standing for 1 hour (L1). Then, the load is removed. The initial load is added again at 30 seconds and 1 hour, respectively, after removing the load, and the length between the two marks is measured (L2 and L3, respectively).

An elongation percentage (%) and an elastic recovery percentage of elongation (%) are determined according to the following expressions.

Measurement results were indicated by an average value of three measurements.

$$\mathrm{Elongation\; percentage}\left(\%\right)=\left(\mathrm{L},,1,-,\mathrm{L},,0\right)\times 100/\mathrm{L}0$$ $$\mathrm{Elastic\; recovery\; percentage\; of\; elongation}\left(\mathrm{after},,30,,\mathrm{seconds}\right)\left(\%\right)=\left(\mathrm{L},,1,-,\mathrm{L},,2\right)\times 100/\left(\mathrm{L},,1,-,\mathrm{L},,0\right)$$ $$\mathrm{Elastic\; recovery\; percentage\; of\; elongation}\left(\mathrm{after},,\mathrm{1},,\mathrm{hour}\right)\left(\%\right)=\left(\mathrm{L},,1,-,\mathrm{L},,3\right)\times 100/\left(\mathrm{L},,1,-,\mathrm{L},,0\right)$$

Elastic recovery percentage of elongation (after 30 seconds) is defined as instantaneous elastic recovery percentage, and elastic recovery percentage of elongation (after 1 hour) is defined as elastic recovery percentage.

An elastic polyurethane fiber of 78 dtex was obtained from a polyether-based polyurethane polymer prepared by using PTMG as a starting material, the polymer containing a hydrotalcite compound represented by the formula (V) in an amount of the metal element content in the fiber of 0.3, 0.5, 2.0, 5.0, 8.0, or 10.0% by weight. The elastic polyurethane fiber was stretched by 4 times in advance. A core-spun yarn was produced using the stretched fiber as a core yarn and cotton as a sheath yarn.

        Mg_4.5Al₂(OH)₁₃CO₃·3.5H₂O     (V)



Cotton yarn dyed with indigo was used as the warp and the above CSY as the weft to produce a 3/1 twill fabric having a warp density of 56 pieces/inch and a weft density of 48 pieces/inch.

The resulting stretch woven fabric was used to produce jeans, which were bleached according to the following procedure.

The stretch woven fabric was agitated in an aqueous solution containing an aqueous sodium hypochlorite solution (available chlorine concentration of 6%) in an amount of 40 g/1 for 10, 20, or 30 minutes, treated with a reducing agent, washed with water or the like, and measured for the elongation percentage, and the elastic recovery percentages of elongation after 30 seconds and after 1 hour.

Table 1 shows the fabric composition and stretch performance after the bleaching. This shows that the resulting stretch woven fabric has excellent stretch performance after bleaching.

A stretch woven fabric and jeans were produced in the same manner as in Example 4 except that as a starting material was used a polyether-based polyurethane polymer prepared by using a copolyether glycol comprising a tetramethylene group and a 2,2-dimethylpropylene group (a copolymerization ratio of a 2,2-dimethylpropylene group of 10% by mole) in place of PTMG. Table 1 shows that the resulting stretch woven fabric has particularly excellent stretch performance after bleaching.

A stretch woven fabric and jeans were produced in the same manner as in Example 4 except that a metal composite oxide represented by the formula (VI) was introduced in place of the hydrotalcite compound. Table 1 shows that the resulting stretch woven fabric has excellent stretch performance after bleaching.



        3ZnO·ZnAl₂O₄     (VI)

A stretch woven fabric and jeans were produced in the same manner as in Example 1 except that the hydrotalcite compound was not introduced. Table 1 shows that the resulting stretch woven fabric has poor stretch performance in that it has a reduced instantaneous elastic recovery percentage after bleaching and a reduced elastic recovery percentage after bleaching for 20 minutes or more.

A stretch woven fabric and jeans were produced in the same manner as in Example 1 except that a commercially available polyester-based elastic polyurethane yarn was used. Table 1 shows that the resulting stretch woven fabric has poor elastic recovery of elongation.

No. Metal element content (% Bleaching time (min) Elongation percentage (% Elastic recovery percentage of elongation (% After 30 seconds Instantaneous elastic recoverv percentage After 1 hour Elastic recovery percentage Example 1 0.3 10 min 37.0 68.2 80.0 20 min 38.0 57.0 70.5 30 min 37.5 53.0 66.9 Example 2 0.5 10 min 37.0 72.0 80.0 20 min 38.0 71.3 78.7 30 min 36.0 72.0 76.2 Example 3 2.0 10 min 38.0 73.0 80.5 20 min 36.0 74.0 78.9 30 min 38.0 74.0 80.0 Example 4 5.0 10 min 37.0 74.0 81.8 20 min 35.0 72.2 80.6 30 min 37.5 74.0 81.8 Example 5 8.0 10 min 36.0 75.0 81.0 20 min 38.0 73.5 79.0 30 min 37.0 74.0 79.0 Example 6 10.0 10 min 35.0 73.0 81.5 20 min 37.0 75.0 80.2 30 min 36.0 74.5 81.3 Example 7 5.0 10 min 37.0 80.0 85.3 20 min 36.0 81.2 86.8 30min 38.0 79.0 86.2 Example 8 5.0 10 min 35.0 74.0 81.5 20 min 36.0 72.7 80.3 30 min 37.0 74.0 81.0 Comp. Ex. 1 0 10 min 37.0 68.8 79.2 20 min 29.0 55.0 68.3 30 min 27.0 52.6 66.7 Comp. Ex. 2 0 10 min 20.0 65.0 73 20 min 21.0 64.0 72.0 30 min 20.0 65.0 74.0

The stretch woven fabric of the present invention can be suitably utilized for woven products such as stretch jeans because the fabric has excellent stretch performance even after bleaching.