JPS6224532B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a mixed twisted yarn with new functions. BACKGROUND ART A mixed twisted yarn is a twisted yarn that gives new performance by twisting two or more types of twisted yarns, single yarns, or spun yarns made of mixed twisted yarns, and currently there are mixed twisted yarns that are made by twisting various types of twisted yarns or single yarns. For example, mixed twisted yarns are known which are made by making a mixed twisted yarn of cotton threads and synthetic fiber yarns to have the desirable properties of both washability and soft touch. As a result of research on mixed twisted yarn, the present inventors found that when a thread made of water-swellable fibers absorbs water, it contracts and is given elasticity. , has new functions,
The present invention was achieved by discovering that a mixed twisted yarn useful for various applications can be obtained. One object of the present invention is to provide a mixed yarn that shrinks when absorbing water. Another object of the present invention is to provide a mixed twisted yarn that is a water-absorbing shrinkable yarn and has excellent strength even when absorbing water. One object of the present invention is to provide a mixed twisted yarn that is stretchable upon absorption of water. According to the present invention, these objects are obtained by twisting together two or more types of twisted yarns, single yarns, or mixed twisted yarns, in which at least one type has water absorbency and has water absorption properties in the yarn direction. Consists of spun yarn (water-absorbing shrinkable yarn) consisting of twisted yarn, single yarn, or mixed twisted yarn that has the property of shrinking by 10% or more of its original length, and at least one type of yarn does not have the property of shrinking in practical terms when it comes into contact with water. This is achieved by using a twisted yarn or a mixed twisted yarn consisting of a spun yarn (non-shrinkable yarn) such as a single yarn or a mixed twisted yarn. The mixed twisted yarn of the present invention shrinks when water is absorbed, has elasticity, and is reinforced with non-shrinkable yarn, so it has excellent strength and achieves the above object. That is, the present invention provides a mixed twisted yarn formed by twisting two or more types of yarns, at least one of which is a water-insoluble first yarn that shrinks in length by 10% or more and is imparted with elasticity upon contact with water. The present invention relates to a mixed twisted yarn characterized in that it consists of at least one other type of yarn or a water-insoluble second yarn whose length does not substantially change even when it comes into contact with water. Examples of water-absorbing and shrinkable yarns that can be used in the mixed twisted yarn of the present invention include modified cellulose fibers such as cotton and rayon, such as carboxymethylated cotton, methylated cotton, ethylated cotton, hydroxyethylated cotton,
Sulfated cotton, sulfonated cotton, phosphorylated cotton, cationized cotton, amphoteric ionized cotton, sodium acrylate, acrylic acid, acrylotrile, acrylamide grafted onto cellulose fibers, etc., and crosslinked products thereof, wool, silk, etc. Examples include water-insoluble threads made of fibers such as the above-mentioned modified products, and modified synthetic fibers, such as partially saponified acrylonitrile fibers and partially maleated vinylon. In addition, non-shrinkable threads (shrinkage rate of 10% or less when in contact with water) include nylon, acrylic,
Threads made of synthetic fibers such as vinylon, polyester, polypropylene, or semi-synthetic fibers such as rayon, acetate, or natural fibers such as hemp, cotton, wool, silk, etc. may be used. As mentioned above, the water-absorbing shrinkable yarn used in the present invention has a shrinkage rate of 10% or more when it comes into contact with water, and has a modulus of elasticity (initial Young's modulus) when it absorbs water and shrinks, and when it is stretched to its original length. Elastic modulus (original long-term Young's modulus)
As shown in the production example below, both are 10 ⁶ ~
10 ⁸ dyne/cm ² and exhibits rubber elasticity,
It has great elasticity. The mixed twisted yarn of the present invention as described above can have slightly different properties depending on whether it is twisted lightly (eg, several 5 per inch) or strongly twisted (for example, several 10 per inch). To explain this with reference to the drawings, FIG. 1 schematically shows the state of the mixed yarn when it is gently twisted, with 1 indicating a non-shrinkable yarn and 2 a water-absorbing shrinkable yarn. Fig. 2 schematically shows the state in which the mixed twisted yarn of Fig. 1 has absorbed water, and it shows that since a large void is created around the water-absorbing contraction yarn 2' when water is absorbed, the water absorbing and retaining power increases and , it can be seen that it also has stretchability. On the other hand, FIG. 3 schematically shows the state of the mixed twisted yarn when twisted somewhat strongly, and FIG. 4 schematically shows the state of the mixed twisted yarn of FIG. 3 in which water has been absorbed. In the case of FIG. 4, the mixed twisted yarn of the present invention takes on a sheath shape upon water absorption, but can be restored to its original length by force in the yarn direction, indicating that it has stronger elasticity. The mixed twisted yarn of the present invention having the above-mentioned properties can be applied to various fields by using appropriately twisted mixed yarn. Typical application examples will be explained below. One application of the present invention is water-absorbing objects. For example, when the twisted yarn of the present invention is used in an absorbent material such as a napkin, tampon, or disposable diaper, when the absorbent material becomes wet with body fluids, voids are created around the twisted yarn,
It has the advantage that more body fluid can be retained in the void space. Another application is a disposable diaper in which an elastic body is provided at the edge around the crotch area, in which the twisted yarn blend of the present invention can be used in place of the elastic body.
The elastic bodies currently used for this purpose are always elastic, which poses problems in terms of use, manufacturing process, and transportation. In other words, during use, the crotch area of the diaper is always sealed by the elastic body, which tends to cause stuffiness, and gives a constant feeling of pressure to the crotch area, making it uncomfortable to wear. Furthermore, in manufacturing, the elastic body must be assembled into the diaper in a stretched state, which poses various difficulties and reduces production efficiency. Furthermore, since the elastic body of the finished product has shrunk, the entire diaper is wrinkled and the product itself is bulky, leading to an increase in transportation costs. On the other hand, if the mixed twisted yarn of the present invention is used instead of the elastic body, the above-mentioned drawbacks can be overcome. For example, in use, since it does not normally have elasticity, a suitable gap can be formed around the thigh area, and it will not get stuffy, and when the mixed yarn gets wet (with urine), it will shrink. Since it has elasticity, the edge of the diaper can be brought into close contact with the thigh area to prevent leakage. In manufacturing, it is sufficient to simply incorporate the mixed twisted yarn of the present invention, which does not have any elasticity (when dry), so that production efficiency does not decrease. In addition, since the twisted yarn of the finished product does not have elasticity before use, the diaper does not wrinkle, and the product itself is not bulky, so transportation costs can be reduced. Another example of application of the present invention is its use as a mixed twisted yarn for knitting and woven fabrics. For example, it can be used in the production of knitted and woven fabrics for swimwear. Currently, swimsuits are
It is given strong elasticity from the beginning to make it fit to the body, and when it gets wet, for example, in the case of knitwear, swimsuits that are tight to the body tend to become loose. On the other hand, when a knitted or woven fabric using the blended yarn of the present invention in part or in its entirety is used for a swimsuit, it is loose before it gets wet, but when it gets wet, the twisted yarn shrinks and tightens to the body. It starts to come. This blended yarn is reusable and can be used many times. The mixed twisted yarn of the present invention can be used for various useful applications in addition to the above-mentioned applications. The present invention will be described below with reference to Examples, but the present invention is not limited thereto. First, an example of manufacturing a water-absorbing shrinkable yarn that can be used in the present invention will be shown. Production example 1 (carboxymethylated cotton) 0.3g of cotton thread (Daruma sewing thread 40/3)
It was immersed in a reaction solution containing 0.8 g of NaOH, 1.83 g of ClCH ₂ COONa, and 60 g of 80% ethanol, left at room temperature for 1 hour, reacted at 60° C. for 6 hours, and neutralized with acetic acid. Then wash 3 times with 80% ethanol,
Wash once with ethanol and then dry. The degree of etherification of the obtained carboxymethylated cotton yarn is 0.35
It was hot. Production example 2 (Methylated cotton) 2.0 g of cotton yarn (Daruma sewing yarn) was immersed in 100 ml of 30% NaOH aqueous solution at room temperature under nitrogen atmosphere for 1 hour, and then compressed until the compression rate was 3 to remove excess NaOH.
Remove it, add it to 100ml of toluene, and add 5ml of dimethyl sulfuric acid dropwise for 1 hour or more while stirring.
After completion of the dropwise addition, stirring was continued at room temperature for 10 hours, after which toluene was removed and the mixture was neutralized with acetic acid. Next, it was washed with 80% methanol (water/methanol = 20/80) and dried. The degree of etherification of the obtained methylated cotton yarn was 0.3. Production example 3 (sulfated cotton) 2.5 g of cotton yarn (daruma sartorial yarn) was immersed in a reaction solution (0.63 g of ammonium sulfate, 13 ml of 1-butanol, 35 ml of 95% hydrochloric acid) cooled to 0° C. for 20 minutes at 0° C. Thereafter, the product was taken out, dispersed in 50% methanol (water/methanol = 50/50), and neutralized with a 5% aqueous sodium acetate solution at 0°C. then 80%
It was washed with methanol (water/methanol = 20/80) and dried under reduced pressure over calcium chloride. The degree of esterification of the obtained sulfated cotton yarn was 0.2. Production example 4 (Cationized cotton) 6.0g of cotton thread (Daruma sewing thread) is 75% containing 3.36g of glycidyltrimethylammonium chloride.
Soaked in 38g of hydrous isopropyl alcohol, 50g
After raising the temperature to ℃, add 0.8 g of 20% NaOH aqueous solution,
The mixture was reacted at 50°C for 9 hours and neutralized with dilute hydrochloric acid. after that
After washing with 80% methanol (water/MeOH=20/80), it was dried. The degree of cationization of the obtained cationized cotton yarn is
It was 0.25. Production Example 5 (Partially saponified acrylic fiber) 5 g of acrylonitrile fiber was immersed in 95 g of 15% NaOH aqueous solution, boiled for 30 minutes with stirring, the product was dispersed in 50% methanol aqueous solution, and neutralized with acetic acid. Washed with 80% methanol and dried. The obtained fibers are spun into 30-count yarn to produce a water-absorbing and shrinkable yarn. The obtained partially saponified acrylic fiber was 2.1 mmol/
It contained -COONa group of g. Table 1 shows the physical properties of the water-absorbing shrink yarn obtained in the above production example upon water absorption. In addition, each of the water-absorbing shrinkable yarns obtained in Production Examples 1 to 5 above and cotton yarn as a non-shrinkable yarn (Daruma sewing yarn) were mixed and twisted (several 5 per inch) to produce a mixed twisted yarn of the present invention (Example 1). Table 2 shows the physical property values at the time of water absorption when 5). There are two methods for assembling water-absorbing and shrinkable yarn, one of which is a method of manufacturing by reacting yarns as in Production Examples 1, 2, 3, and 4.
The other method is to react the fibers and then spin them into yarn as in Production Example 5, and either method may be used.

[Table] Example 5

[Table] It can be seen from Tables 1 and 2 that the obtained mixed twisted yarn achieves the object of the present invention. More detailed examples will be shown below using carboxymethylated cotton yarn as the water-absorbing shrink yarn. There are two methods for producing the mixed yarn of the present invention, one of which is a method of producing a water-absorbing shrinkable yarn and then twisting it with a non-shrinkable yarn (two-stage method), as shown in Examples 1 to 5 above. method) and the other is,
A method for producing the mixed twisted yarn of the present invention (1) by twisting yarns before reaction to form a water-absorbing shrink yarn and yarns that do not react with the reaction solution, and then reacting only the former to form a water-absorbing shrink yarn (1). There is a tiered method). Example 6 (Two-stage method) Water-absorbing shrinkable yarn: Carboxymethylated Daruma basting yarn 40/3 (40 count 3 strands) Non-shrinkable yarn: Daruma basting yarn In production example 1, the reaction time was 2, Water-absorbing shrink yarns are produced at 4, 6 and 9 hours, after which they are twisted with non-shrink yarns. The degree of etherification of the obtained water-absorbing shrink yarn was 0.12, 0.27 at reaction times of 2, 4, 6 and 9 hours, respectively.
It was 0.35 and 0.40. Example 7 (One-stage method) Water-absorbing shrinkable yarn: Carboxymethylated Daruma basting yarn 40/3 Non-shrinkable yarn: Vinylon basting yarn After twisting Daruma basting yarn and non-shrinkable yarn to make a mixed twisted yarn, Carboxymethylation reaction was carried out under the reaction conditions shown in Example 6. Example 8 Water-absorbing shrinkable yarn: Carboxymethylated-crosslinked Daruma basting yarn 40/3 Non-shrinkable yarn: Daruma basting yarn 40/3 Carboxymethylated Daruma basting yarn under the reaction conditions shown in Production Example 1 The yarn is cross-linked with glyoxal to make water-absorbing and shrinkable yarn. The crosslinking reaction was carried out by adding 0.5, 1.0, 1.5 and 2.0% of 40% glyoxal based on the amount of 80% ethanol into 80% ethanol that was 10 times the weight of the carboxymethylated sartorial yarn, and then adding 40% glyoxal to the carboxymethylated sartorial yarn. The thread is immersed, stirred for 5 minutes, filtered and reacted at 105°C for 30 minutes. Next, the carboxymethylated crosslinked water-absorbing shrinkable yarn obtained by the above reaction and the non-shrinkable yarn are twisted together to form a mixed twisted yarn. Tables 3 and 4 show the physical properties of the water-absorbing shrink yarns and mixed twisted yarns obtained in Examples 6 to 8 above, respectively.

【table】

【table】

[Table] From the above results, it can be seen that the mixed twisted yarn of the present invention shrinks when absorbing water, exhibits rubber-like properties, and has strong strength. Next, application examples of the mixed twisted yarn of the present invention will be shown below. Application example 1 Divide 26 g of cotton-like pulp (SAM from Wehaeuser Co., Ltd.) into two halves to make an absorber, and as shown in Figure 5, between the absorbers 5 and 5, the mixed yarn obtained in Example 6 (reaction time 9 hours) was placed. Arrange 5g as shown by 3 in the figure,
Incorporate into the absorber. The top sheet 4 is made of 20 g/m ² of heat-fused nonwoven fabric of 45% polyester fiber and 55% ES fiber, and the back sheet 6 is made of polyethylene 25 g/m ² as shown in Figures 5 and 6. . 3' in FIG. 6 shows the mixed twisted yarn that has absorbed water. The performance of this absorber is shown in the table below in terms of absorption time and return amount.

[Table] Body The absorption time is the time taken to absorb 60 c.c. of artificial urine through a hole of 1 cm in diameter in the container where the absorbent surface is placed, and the amount returned is determined after 2 minutes. The measurement was made by applying a load of 40 g/cm ² to a 100 cm ² area around the absorption point and absorbing the amount that oozes out from the absorber into a filter paper. The above excellent results are due to the fact that by incorporating the twisted yarn of the present invention into an absorbent body, when the absorbent body gets wet, voids are created around the twisted yarn, which increases the amount of liquid retained and reduces the amount of liquid that returns to the outside of the absorbent body. This is thought to depend on what happens. Application Example 2 The mixed twisted yarn obtained in Example 8 (carboxymethylated for 6 hours) was placed in the crotch of a disposable diaper, 10 on each side, as shown by reference numeral 8 in Figures 7 and 8, and the mixed yarn was hot-melted at 1 cm intervals. Glue and secure to the diaper. Note that 7 indicates a water absorbent body. When artificial urine is absorbed into the diaper made in this way, when the synthetic urine comes into contact with the mixed yarn, the mixed yarn contracts and the edge of the diaper comes into close contact with the thigh area as shown in Figure 9. It becomes a shape.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view of a slightly twisted mixed yarn of the present invention, Fig. 2 is a schematic side view showing the state in which the mixed yarn of Fig. 1 has absorbed water, and Fig. 3 is a slightly strongly twisted mixed yarn of the present invention. 4 is a schematic side view showing the state in which the mixed twisted yarn of FIG. 3 has absorbed water, FIG. 5 is a cross-sectional view of an absorbent body using the mixed twisted yarn of the present invention, and FIG. Fig. 5 is a cross-sectional view showing the state in which the water absorbent absorbs water, Fig. 7 is a plan view of a disposable diaper using the yarn blend of the present invention, Fig. 8 is a cross-sectional view thereof, and Fig. 9 is the diaper shown in Fig. 7. It is a perspective view showing a state in which water is absorbed while being worn. 1...Non-shrink yarn, 2...Water-absorbing shrink yarn, 2'...
Water-absorbed shrinkable yarn, 3... Invention blended yarn, 3'
...Absorbed blended yarn of the present invention, 4...Top sheet,
5... Absorbent body, 6... Back sheet, 7... Absorbent body, 8... Mixed twisted yarn of the present invention.

Claims (1)

[Scope of Claims] 1. In a mixed twisted yarn formed by twisting two or more types of yarns, at least one of them is a water-insoluble yarn that shrinks in length by 10% or more and is imparted with elasticity when it comes into contact with water. A mixed twisted yarn comprising a first yarn and at least one other kind of water-insoluble second yarn whose length does not substantially change even when it comes into contact with water. 2. The mixed twisted yarn according to claim 1, wherein the first yarn is a yarn made of carboxymethylated cellulose.