JPS61239034A - Highly water absorbable spun yarn - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to superabsorbent spun yarns. More specifically, it relates to a highly water-absorbent spun yarn that is excellent in water absorption and hygroscopicity and has a unique texture and appearance.

BACKGROUND OF THE INVENTION Synthetic fibers such as acrylic synthetic fibers and polyester synthetic fibers have extremely low water absorption and absorbency compared to natural fibers such as cotton and wool. Therefore, in applications that come into contact with the human body in a wet state, such as mats placed at bathroom entrances and underwear, it is uncomfortable to wear, and is currently being reduced by blending it with highly absorbent cotton. .

As this improvement method, for example, JP-A-54-142347
The publication proposes an acrylic spun yarn in which the inner layer is made of porous water-absorbing acrylic fibers and the outer layer is made of ordinary acrylic fibers.

However, the water absorption rate (R0) of microporous water-absorbing acrylic fibers is only a few tens of centimeters and does not exceed 100 centimeters, which is insufficient for water absorption, and water is retained between the zeid and rut fibers in the fibers. If pressure is applied to the yarn while it is wet, the water will be squeezed out onto the surface of the yarn.

For example, if the spun yarn is used in a so-called mat placed at the entrance to a bathroom, water will be retained in the system and there will be no wet feeling when a small number of people (one or two) are using it, but when a large number of people are using it, At first glance, the water seemed to have been absorbed into the system, but the pressure from stepping on it with my foot squeezed the water out, making me feel wet and extremely uncomfortable.

Problems to be Solved by the Invention The object of the present invention is to provide a super absorbent spun yarn that takes advantage of the excellent water absorbing performance of super absorbent fibers that eliminates the drawbacks in practical performance.

Means for Solving the Problems The superabsorbent spun yarn which is the object of the present invention can be achieved by the following structure.

That is, the present invention consists of a fiber bundle containing super absorbent fibers with an inner layer having a water absorption rate (R0) of 300% or more, an outer layer having a water diffusion rate of 5 seconds or less, and an official moisture content of 4.5. It is composed of the following hydrophobic fibers, and has a water absorption rate (R) of 1 as a spun yarn.
A super-absorbent spun yarn characterized by having a water absorbency of 60% or more.

The present invention will be explained in detail below.

In the super absorbent spun yarn of the present invention, a large amount of moisture is retained in the inner layer of the yarn, and the surface of the yarn feels dry, and even when pressure is applied or squeezed, moisture flows back to the surface of the yarn. It's something that doesn't come out.

The super absorbent fibers constituting the inner layer are, for example, 3-denier acrylic synthetic fibers made of a copolymer of 80% polyacrylonitrile and 20% acrylic acid, immersed in a caustic soda aqueous solution at room temperature for 60 minutes, and then soaked in 10% water. It can be obtained by thoroughly washing in an ethanol solution containing ethanol, dehydrating it, and then drying it. The water absorption rate (R0) of this fiber is 5000% and the moisture absorption rate is 2
4% (after being left for 24 hours in an atmosphere of 20° C. and 65% RH).

Incidentally, the water absorption rate of the fiber is expressed by the following formula.

O Wo: Absolutely dry fiber weight Wl: Water-absorbing fiber weight (diameter 30 crn after immersed in purified water for 1 hour, rotation speed 300
After dehydrating for 30 seconds in OR, P, m, dehydrator) Others,
To obtain such super absorbent fibers, Japanese Patent Publication No. 52-4219
Publication No. 6, Special Publication No. 10508/1983, Special Publication No. 1988
Methods described in JP-A-10509, JP-A-57-82566, etc. may also be used, and the method is not particularly limited.

The water absorption rate of such super absorbent fibers can be adjusted by processing conditions, and as disclosed in the above-mentioned patent publication, it is easy to obtain an extremely high water absorption rate, and the water absorption rate of natural fiber cotton is 97 cm, or Microporous water-absorbing acrylic acid 2
This is much higher than the 84% water absorption rate of, for example, Tonover (trademark manufactured by Niinil, West Germany).

However, there are problems with the fishing properties of high water absorption, which is the original purpose of super absorbent spun yarn, such as low wet strength and elongation, abrasion resistance, and wet friction fastness, and a strong wet feeling. A yarn made of 100% super-absorbent fibers or a normal blended yarn with other fibers cannot be put to practical use because the super-absorbent fibers are exposed on the surface of the yarn.

The present invention was developed as a result of intensive studies to improve these problems.
This can be achieved by using a two-layer yarn structure consisting of highly absorbent fibers in the inner layer and hydrophobic fibers with a high water diffusion rate in the outer layer.

The water absorption rate (R0) of the super absorbent fibers of the fiber bundle constituting the inner layer portion used in the present invention must be 300 cm or more, and the upper limit of the water absorption rate is not particularly limited, but the water absorption rate (R0) is 1
If it is less than 50, water absorption is insufficient.

The inner layer fiber bundle can be used as a composite fiber bundle of super absorbent fibers and ordinary rutted fibers, or can also be used in the form of long fibers.

High water absorption - The blending ratio of fibers needs to be set so that the water absorption rate (as spun yarn) is 160% or more, and if the water absorption rate (@) as spun yarn is less than 90, the water absorption is insufficient. It is.

Here, the water absorption rate (R) of the highly absorbent spun yarn is calculated using the following formula.

(R): Water absorption rate of spun yarn.

A: Mixing ratio of super absorbent fibers constituting the inner layer fiber bundle.

Ro: Water absorption rate of super absorbent fiber.

B: Mixing ratio of normal fibers.

R1: Water absorption rate of normal fiber.

C: Mixing ratio of outer layer fibers.

R2: ・Water absorption rate.

The fibers constituting the outer layer of the present invention must have the ability to quickly rotate into the fiber bundle constituting the inner layer without absorbing water coming from the outside, and must be hydrophobic fibers and have a low water diffusion rate. It needs to be big.

Here, the term "hydrophobic fiber" refers to a fiber having an official moisture content of tSS or less. For example, acrylic, polyester, nylon, polypropylene fibers, etc. are used.

Rayon (official moisture content 11%), cotton (official moisture content &5
H) etc. give a very wet feeling when absorbing water and cannot be used in the present invention.

Fibers with a high water diffusion rate are those that are used to make knitted fabrics and have a water absorption rate of 5 seconds or less as measured by the dropping method (JIS, L-10966, 26, IA method). . Fibers with a water absorption rate of 20 seconds have a slow water absorption and give a very wet feeling when water is absorbed, so they cannot be used in the present invention.

The method for producing a superabsorbent spun yarn having a two-layer structure consisting of an inner layer and an outer layer according to the present invention uses separate draft zones for inner layer fiber bundles and outer layer fiber bundles in a roving machine, and an assistant This is done by using a pair of rollers to allow overfeeding of the outer layer fiber bundle. The feed rate may be arbitrarily selected from 6 to 26 depending on the purpose and thickness of the yarn to be spun. If the feed rate is less than 6%, the coverage by the outer layer fiber bundle will be insufficient, and if it is 28 inches or more, the appearance of the yarn will be poor. The outer layer fiber bundle is wound before the inner layer fiber bundle reaches the seven-layer fiber bundle, and is heated while being heated by the rotation of the flyer. In this way, the outer layer fiber bundle is wound around the inner layer fiber bundle to form a spun yarn, so there is no drafting after winding, so a super absorbent spun yarn with a bulky two-layer structure can be obtained. It will be done.

The spun yarn thus obtained is formed by winding the outer layer spun fiber bundle around the inner layer spun fiber bundle extending in the yarn axis direction, and the number of twists of the inner layer spun fiber bundle is When the number of twists of the outer layer fiber bundle is T2, the twist angle of the inner layer fiber bundle is Q1, and the twist angle of the outer layer fiber bundle is Q2, T1 is substantially equal to T2, and Q
z > Q r; and the inner layer fiber bundle is 6 to 26
% oats - Because the yarn is fed and wound, there is a gap between the outer circumferential surface of the inner layer fiber bundle and the outer layer fiber bundle, and this gap causes the inner layer fiber bundle to move in the longitudinal axis direction of the spun yarn. Since they are arranged randomly on each part of the outer circumferential surface of the fiber bundle, the bulkiness of the system as a whole is imparted, and even if the super absorbent fibers constituting the inner layer absorb water and swell, the outer circumferential surface of the inner layer fiber bundle The superabsorbent fibers are absorbed into the voids randomly arranged in each portion of the fibers, so that the superabsorbent fibers do not break through the outer layer fiber bundle covering the fibers and are exposed to the outer surface of the spun yarn.

The twist coefficient of the super absorbent spun yarn of the present invention may be selected to be 40 to 130, preferably 60 to 100 in α value (m twist coefficient). If the α value is 40 or less, the strength of the super absorbent spun yarn will be too low, and if the α value exceeds 130, the super absorbent spun yarn will become hard. In addition, the twist angle of the outer layer fiber bundle is 30° ~
An angle of 80°, preferably in the range of 40° to 70' is suitable for obtaining the bulkiness and voids randomly arranged on the outer peripheral surface of the inner layer fiber bundle. The twist angle of the unidirectional layer fiber bundle is preferably in the range of 20° to 70°. Other manufacturing methods are not limited to the above-mentioned roving frame, but may also be a spinning frame that has a pair of assistant rollers and has separate draft zones for inner layer fiber bundles and outer layer fiber bundle draft zones, The manufacturing method is not particularly limited.

The super absorbent fiber constituting the inner layer of the example is an acrylic synthetic fiber made of a copolymer of 80% polyacrylonitrile and 20% by weight of acrylic acid, with a total denier of 3 denier and 50% total denier.
A tow of 10,000 denier was immersed in an aqueous solution of caustic soda at 20 DEG C. for 60 minutes, washed with a solution consisting of tow-it% water and 90 wt% ethanol, and then dried. At this time, by adding an appropriate amount of calcium to the caustic soda aqueous solution, the water absorption rate (R0) can be increased to 5000%, 1000%, and 500%.
%, 300%, and 150 cm were produced and cut into fiber lengths of 51 ml and 1 m. The fibers that make up the outer layer ffl fibers include oak, which has a different water diffusion rate. O (trademark for acrylic fibers of Asahi Kasei Industries, Ltd.) A-line fiber water diffusion rate 1 second or less), Cashmilon B fiber (water diffusion rate 5 seconds), Cashmilon C fiber (water diffusion rate 20 seconds) 2dX 51 weight M Yarn-dyed fibers and
Leonasf with different official moisture content (trademark of polyamide fiber of Asahi Kasei Corporation, official moisture content 4.s%)2
Yarn dyed fiber of d×51 and Egyptian M (official moisture content &5
H) yarn-dyed fibers were used.

Nol to N shown in Table 1 using the above various fibers.

A highly water-absorbent spun yarn having a two-layer structure consisting of an inner layer and an outer layer was spun with the fiber composition shown in Table 9. The method for producing the spun yarn includes a method of manufacturing fiber bundles for the inner layer and fiber bundles for the outer layer.
is produced separately using a normal card and filament process, and then using a flyer-type roving frame having separate inner layer fiber draft zones and outer layer fiber bundle draft zones, and an assistant roller. Then, the corresponding fibers are supplied to the fiber bundle draft zone for the inner layer and the outer layer fiber draft zone, respectively, and the inner layer fibers are made of super absorbent fibers sent out from the draft zone. The feeding speed of the outer layer fiber bundle to be sent out from the draft zone with respect to the inner layer fiber bundle was set so that the outer layer fiber bundle could be fed 24 degrees by using an assistant roller. The outer layer collar fiber bundle was wound before the inner layer fiber bundle reached the flyer top, and a single yarn with a twist number of 267 T/M of 1/8 Nm was spun by heating by rotation of 7 layers. Next, the yarns were combined and twisted using a conventional ring twisting machine to produce a super absorbent spun yarn of 2/8 NFFI with a number of twists of 180 T/M.

Using these yarns, a mat with a pile length of 15 m was prepared by tufting a cotton base fabric using a no-do tufting machine. Table 1 shows the evaluation results.

Among the evaluation items, the wet feeling of the mat was evaluated by the feeling of use when the mat manufactured by the above method was placed at the entrance of the bathroom and used by the fifth person after taking a bath.

No. 2.3.4.6.8 in Table 1 are examples of the present invention, and No. 5, 7, 9, and 10.11 are comparative examples. No
3 used super absorbent fibers with a water absorption rate (R0) of 150 inches, and the mat felt slightly wet; There was N0
The mats of the present invention examples with 1°2 and 3.4 did not feel wet at all and had the same texture as when dry. Comparative example No. 7 uses Egyptian cotton for the outer layer fiber bundle, and the water absorption rate of the mat is high, but since the outer layer fibers are hydrophilic and absorb water, the feeling of wetness is large and is insufficient for the present invention. Met. No
Comparative example No. 9 used fibers with a water diffusion rate of 20 seconds for the outer layer fibers, and water droplets remained on the pile yarn surface of the mat and gave a wet feeling. Inventive example No. 8 used in the above was excellent with no matte wet feeling. Comparative example No. 0 is a normal blended spun yarn made by blending super absorbent fibers with the aforementioned Cashmilon fibers, which are hydrophobic and have a high water diffusion rate, in the blending process. Since the fibers were exposed on the #spun yarn surface, the wet feeling was poor and the fastness to wet rubbing was inferior to that of the yarn. Furthermore, the comparative example of N011 is a commercially available mat, and when it was placed in the bathroom entrance and exit described above, it felt extremely wet, and when a fifth person used it, the water squeezed out due to the pressure of stepping on it. On the other hand, in No. 2.3.4.6.8 of the present invention, not only the water absorption rate of the mat is extremely high, but also the above-mentioned feeling of catching is not practical. In the evaluation, there was no feeling of wetness, and even when the fifth person used it, water did not squeeze out even when pressure was applied by stepping on it.
It had the same dry feel as before use, and also had good general physical properties such as fastness to wet rubbing, and had extremely excellent performance.

Effects of the Invention The highly water-absorbent spun yarn of the present invention not only has extremely high water absorption and hygroscopicity, but also has an outer layer composed of hydrophobic 412 fibers with a high water diffusion rate. The shoulder fiber bundle quickly transfers water coming from the outside to the inner layer fiber bundle, and as the highly water-absorbent fibers absorb water, the surface of the spun yarn becomes inner jf.
Part I Highly handled super absorbent fibers There is no change in texture even when wet with water compared to when dry, and super absorbent fibers have low elongation, abrasion resistance, and dye fastness to wet friction when wet, and have a low wet feeling. The disadvantages such as large size can be completely eliminated. In addition, in the super absorbent spun yarn of the present invention, since the outer shoulder fiber bundle is wrapped around the inner layer fiber bundle in an oat-safe manner, the outer peripheral surface of the inner layer fiber bundle and the outer shoulder fiber bundle are There is a void in between, and even if the superabsorbent fibers constituting the inner first layer absorb water and swell due to this void and the diameter of the inner layer fiber bundle increases, the superabsorbent fiber absorbs water through the void and the superabsorbent fibers absorb water. It does not break through the outer shoulder fiber bundle covering the fibers and expose the outer surface of the spun yarn, and can greatly improve the texture, appearance, and various physical properties of the highly water-absorbent spun yarn when water is absorbed. be. Furthermore, when we conducted a practical test using the spun yarn to make a mat to be placed at the entrance to a bathroom, we found that the cotton mat hardly felt wet when the first person used it after taking a bath, but when the second person used it, it felt wet. When the mat comes out and the fourth person steps on it, the water that was absorbed before is squeezed out and it is very uncomfortable. Even when the fifth person used it, the wetness was not felt and it was very appealing.

Claims (1)

[Claims] Hydrophobic, consisting of a fiber bundle containing super absorbent fibers with an inner layer water absorption rate (R_0) of 300% or more, an outer layer water diffusion rate of 5 seconds or less, and an official moisture content of 4.5 or less A highly water-absorbent spun yarn made of fiber and characterized by a water absorption rate (R) of 160% or more as a spun yarn