JP2003342862A - Water-absorbing material and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-absorbing material excellent in the water absorbing amount and wet feeling, withstanding washing at a high temperature which laundrymen carry out and excellent in reutilizing properties, and to provide a method for producing the water-absorbing material. <P>SOLUTION: The fabric-like water-absorbing material is composed of fibers and has ≥10 cc porosity per 100 cm<SP>2</SP>, 1 mm-20 mm thickness and ≤6% shrinkage factors in length and width after 10 times-repeated industrial washing. The main fiber constituting the fabric-like water-absorbing material is a synthetic fiber having 0.01-2 dtex fineness. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water absorbent material composed of fibers and a method for producing the same, and more specifically, it is suitable for diapers, clothes, miscellaneous goods, bedding and the like used in hospitals, nursing homes, homes and the like. It is a water absorbing material used,
The present invention relates to a water-absorbing material excellent in shape stability even after repeated washing at high temperature such as industrial washing, and a method for producing the same.

[0002]

2. Description of the Related Art Materials which have been conventionally used as water absorbent materials such as diapers have been mainly cloth-like materials such as cotton and rayon, and acrylic polymer absorbents.

The one using cloth such as cotton and rayon has been used as a diaper that can be repeatedly washed and used. However, when the diaper has poor water absorption performance and adheres to the skin after urination, the feeling of wetness on the surface leads to discomfort. It was unpopular.
In addition, there is a problem that after being used in a hospital or a nursing facility, a contractor etc. contracts because of severe washing.

On the other hand, a diaper using an acrylic polymer absorbent as an absorbent has been widely used as a disposable paper diaper because of its convenience. However, with the increase in the amount of disposable diapers used, the disposal of used disposable diapers has become a social problem as industrial waste.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves these conventional problems, is excellent in water absorption and wet feeling, can withstand washing at high temperature performed by a trader, and is excellent in reusability. And a method of manufacturing the same.

[0006]

The present invention employs the following means in order to solve the above problems.

That is, a cloth-like water-absorbing material made of fibers, having a void volume per 100 cm ² of 10 cc or more, a thickness of 1 mm to 20 mm, and a shrinkage rate of 6% or less in vertical or horizontal after 10 industrial washings. And the main fibers constituting the cloth-like water-absorbing material have a fineness of 0.01 dtex to 2
A water absorbing material, which is a synthetic fiber of dtex.

Further, a cloth-like water absorbing material made of fibers, wherein the cloth-like water absorbing material is previously shrunk by heat, and the void amount per 100 cm ^{2 of the} cloth-like water absorbing material is 10 cc.
As described above, the thickness is 1 mm to 20 mm, the vertical or horizontal shrinkage rate after industrial washing 10 times is 6% or less, and the main fiber constituting the fabric-like water absorbent material has a fineness of 0.01 dtex.
To 2 dtex of synthetic fiber.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The water-absorbent material used in the present invention is made of a fabric made of fibers.

The cloth-like shape means a sheet-like shape such as a non-woven fabric, a woven fabric or a knitted fabric, and any one having such a form can be used. Among them, the non-woven fabric is preferable because the thickness, the amount of voids, and the like can be appropriately changed and the cost is advantageous. Such a cloth is composed of fibers and voids, but in order to improve water absorption, it is necessary to increase the voids and the surface areas of the single fibers so as to retain water by a capillary phenomenon.

It is necessary that the cloth-shaped water absorbing material has a void volume per 100 cm ² of 10 cc or more. The void amount is indicated by a value obtained by subtracting the volume occupied by the fibers from the volume of the cloth. That is, the amount of water absorbed is the amount absorbed by the capillary phenomenon, and the larger the amount, the better.

Empirically, the amount of voids per 100 cm ² is 1
If it is less than 0 cc, the amount of voids is small and water is not absorbed. For example, when it is used for a diaper, liquid leakage occurs, and therefore it cannot be used. The amount of urine per dose is 15
It is 0 cc to 200 cc, and normally, the water absorbing material used for the diaper is about 300 to 1000 cm ² ,
The effect is sufficient if the maximum void amount per cm ² corresponding to two or more doses is 500 cc. The upper limit is not particularly limited, but if it is more than this,
There are cases where the space is too large to eliminate the capillary phenomenon, and the compressed amount is large when the space is pressed, so that the contained water is pushed out, which is not preferable.

The thickness of the cloth-like water-absorbing material is preferably as thin as possible from the viewpoint of handleability, but is preferably as thick as the amount of voids. At least 1
mm must be present, preferably up to 20 mm. If it is 1 mm or less, the amount of voids is small, and therefore the amount of water absorption is small and it cannot be used. If it is 20 mm or more, the amount of voids is large and the amount of water absorption is large, but it cannot be used from the viewpoints of handleability, discomfort during wearing, and price. Most preferred is 3 to 15 mm.

The fineness of the fiber is important. The thinner the fiber, the larger the surface area of the fiber per unit weight, and the smaller the space between the fibers, so that the capillary phenomenon can be effectively utilized and the retention of water is improved. It must be from 01 dtex to 2 dtex. If it is thinner than this, the water retention is too good, and the washability and dryness deteriorate, so that it cannot be used. Further, since the single fiber does not have rigidity, there arises a problem that retention of voids is deteriorated. If it is 2 dtex or more, the fibers are too thick and the spaces where fibers are formed become large, so that the retention of water becomes poor, and at the same time, the movement of water tends to occur during use, and the exudation of water tends to occur.

The cloth-like water-absorbing material according to the present invention needs to be mainly composed of synthetic fibers. In the case of natural fiber, the fiber itself absorbs water so that the fiber itself feels wet and feels uncomfortable during use.Also, it is deteriorated by washing when repeatedly used, especially at high temperature and alkalinity to effectively remove stains. This is because deterioration with a strong detergent is fast. However, when used as multiple layers, the central layer is a natural fiber with water absorption and hygroscopicity, such as cotton, wool,
The use of cloth such as linen makes it possible to use such a problem because such problems hardly occur.

Of course, the acrylic polymer water absorbent, which is often used for paper diapers and the like, is not preferable because it cannot be washed and therefore it is thrown away so that it causes a problem of industrial waste.

Synthetic fibers include polyester, polyamide,
Any of acrylic, polypropylene, polyethylene and the like can be used, but polyester fibers and nylon fibers are preferable in consideration of durability against washing under severe conditions such as industrial washing at high temperature and subsequent drying.

The cloth-like water-absorbent material used in the water-absorbent material of the present invention has a vertical or horizontal shrinkage ratio of 6 after 10 industrial washings.
Must be less than or equal to%. This is because if the shrinkage ratio of the length and the width after 10 industrial washings exceeds 6%, the water absorbing material is largely deformed and cannot be repeatedly used. In the case of diapers using this, the difference in shrinkage rate between the permeable and waterproof materials that are sewn at the same time causes puckering, which reduces the product value and at the same time causes leakage and reverse flow of water, making it unusable. .

Withstands severe washing conditions such as industrial washing,
As a means for obtaining such a stable shape without deformation, it is necessary to shrink the cloth-like water-absorbing material made of fibers in advance at a temperature higher than the heat history given during industrial washing. Specifically, after forming the cloth-like water-absorbing material into a cloth, cutting it into a predetermined shape for sewing, or after making it into a product shape, a temperature higher than the heat history applied during industrial washing is dry heat, wet heat or hot water. That is, heat treatment is performed by any of the above methods to shrink. Usually washing is done in warm water,
It is most preferable to use hot water of 80 ° C. or higher for this heat treatment means. The treatment time may be shorter than the high temperature washing time at the time of washing as long as the treatment temperature difference is large, but preferably the same or longer is more effective.

The state of the cloth-like water-absorbing material at the time of such treatment may be any state as long as it shrinks, and either continuous treatment or batch treatment may be used. In the case of continuous treatment, even if heat treatment is performed in a restricted state so that the shrinkage in the width direction does not exceed a certain ratio, even if it is treated without tension in the width direction so that it can freely enter. Good.
It is preferable to treat without tension in order to reduce the shrinkage ratio as much as possible. More preferably, it is preferable that both the length and the width are allowed to shrink freely, and the length and the width are easily reduced to 6% or less. As specific heat treatment equipment,
A jet dyeing machine can be used for hot water treatment, and a device used for dyeing such as a sanforise shrinkage prevention device can be used for dry heat treatment, but a washer type hot water treatment machine or a tumbler type machine can be used because of the merit of being able to perform heat treatment in a more tensionless state. A dry heat treatment machine or the like can be preferably used.

In the water absorbing material of the present invention, it is preferable that the water absorbing agent is attached to the surface of the constituent fibers of the fabric-like water absorbing material and the water absorption by the Bayrek method is 50 mm or more. The water absorbent is
It is not particularly limited as long as it can impart water absorption, but is preferably one having excellent durability against washing and the like. Specifically, silicone-based, polyester-based, polyamide-based, acrylic-based, or urethane-based water-absorbing agents, cation-based, anion-based, nonionic-based water-absorbing agents, low-molecular-weight, polymer-based water-absorbing agents, etc. For example, a water absorbing agent such as a special nonionic Lanogen KRN-6 (manufactured by Takamatsu Oil & Fat Co., Ltd.) or a polyester resin TO-SR-1 (manufactured by Takamatsu Oil & Fat Co., Ltd.) is applied to the fiber surface. Water absorption (Bay Rec method) is 5
If it is less than 0 mm, the diffusion of water is poor and the water absorption is poor.
Water leakage easily occurs.

The water absorbing material used in the present invention preferably has a water absorption amount (water absorption rate) of 100% or more.
If it is less than 00%, it cannot be said that the water absorbing property is sufficient, and it may not be preferable. More preferably, it is 250% or more, and the diaper has excellent water absorption.

The density of the water absorbing material according to the present invention is not particularly limited, but preferably 0.07 to 0.5 g.
The range is / cm ³ . If it is less than 0.07 g / cm ³ , the amount of voids increases, but the retention of water due to the capillary phenomenon and the exudation of water when pressed due to an increase in the compression rate increase in some cases, which is not preferable. Also,
On the other hand, when the amount is 0.5 g / cm ³ or more, the fiber occupying space is large and the water content is small, which is heavy, hard and expensive, which is not preferable in some cases. The most preferred range is 0.1-0.
It is 4 g / cm ³ .

The cloth-shaped water absorbing material used for the water absorbing material of the present invention is
The compression rate is preferably 30% or less. 30%
When it exceeds the above range, when the cloth-like water-absorbing material contains water, when it is pressed with a finger or the like, the cloth-like water-absorbing material is dented and the amount of voids is reduced, and the water is exuded by that amount, which may be unsuitable for the purpose of use of the diaper. Further, a material which is not compressed at all may be too hard and may cause a problem in use, and the compression rate is preferably 2% or more.

The fabric-like water absorbent material of the present invention has a basis weight of 500 g.
/ M ² or more is preferable. If it is less than 500 g / m ^2, it may not be possible to obtain the expected water retention amount, especially when used as a water absorbent material such as an adult diaper that has a large amount of urine output, which is a problem when used for a long time at night. May occur.

The cloth-shaped water absorbing material used for the water absorbing material of the present invention is
It may be used as a single layer or may be composed of a plurality of layers. The plurality of layers referred to here means that one fabric-like water-absorbing material is formed by laminating a plurality of layers of the cloth-like water-absorbing material, and layers of the same kind are overlapped, and the fineness and cross-sectional shape of the constituent fibers are It is meant to be combined with a layer made of different fibers. It is preferable that the cloth-like water-absorbing material is composed of a plurality of layers, because the number of laminated layers can be adjusted according to the required water-absorption amount of the product, and the desired water-absorption amount can be easily met. Further, by stacking a plurality of layers, it is generally easy to bend, probably due to displacement between layers due to bending deformation, and it can be expected that the water absorbing material becomes soft. The number of layers to be laminated is not particularly limited, but it is preferably 2 to 20 layers so as to be able to handle finely. In addition, a part of the cloth-shaped water absorbent material composed of these plural layers may be sewn or joined by needle punching or the like.

Further, in order to prevent the water from seeping out further when the cloth-like water absorbing material is compressed, it is preferable to combine a fiber layer, which should be called a running water layer, in the cloth-like water absorbing material. The running water layer is made of the same cloth-like material, or knitted, woven, or non-woven cloth, and when the water retained by the cloth-like water absorbent is compressed and the water seeps out, it flows into the running water layer to the surface. It is a layer that functions so as not to cause seepage. Such a water-passing layer is generally composed of fibers thicker than the water-absorbing layer which should be called a water-retaining layer in the fabric water-absorbing material,
The structure is preferably rough, and although water may be moved by a capillary phenomenon, water is hardly retained in the layer. When the capillary phenomenon as described above is caused, the larger the difference in thickness between the constituent fibers of the water retaining layer and the flowing water layer is, the better, but it is preferably about 2 to 1000 times.

The combination of the running water layers may be arranged on any of the front and back surfaces of the water retaining layer or the inner layer, but it is preferably placed in the inner layer. Such a plurality of layers can be joined by laminating and using any joining method such as punching with a needle or a water stream, bonding with an adhesive, and bonding by sewing. When these running water layers are used, a laminate of the running water layer and the water retaining layer (water absorbing layer) corresponds to the cloth-like water absorbing material according to the present invention.

The cross section of the fiber used in the water absorbent material of the present invention is solid, hollow, T-shaped, flat, tear-shaped or Y-shaped, cross-shaped, * -shaped,
It can be used in any cross-section such as a multi-leaf type such as a rice character type. In particular, those having a large fiber surface area are preferable, such as T type, H type, π type, tear type, Y type, cross type, * type,
A complex cross-section such as a multi-leaf type such as a U.S. type is particularly preferable because it retains water well. FIG. 2 is a schematic model diagram showing an example of the cross-sectional shape of these fibers.

The structure of the water-absorbing material of the present invention may be non-woven fabric, woven fabric, knitted fabric, or the like.
A non-woven fabric is preferable for easy handling and uniform void volume. Bonding of fibers to obtain a non-woven fabric includes needle punching, water jet punching, heat setting,
Any method such as an adhesive may be used. As means for obtaining fibers having a fineness of 1 dtex or less, any of melt-blown, spunbond, fibers obtained by eluting a sea part using a sea-island fiber with a chemical solution, fibers obtained by dividing composite fibers with a high-pressure water stream, and the like can be used. Can be used.

Preferably, it is a method of producing a nonwoven fabric by means of dividing into short fiber webs of splittable conjugate fibers consisting of two types of incompatible polymers, and splitting by a high-pressure water flow, which is a stable nonwoven fabric structure, Since the work of dividing the composite fiber into a plurality of pieces is completed at once, the cloth can be obtained at a low cost. The method of simply making the fine fibers into a non-woven fabric as it is may be unfavorable in terms of processing, especially since it easily causes problems in passing through a card machine.

Although melt-blowing, which is a long-fiber non-woven fabric, can obtain fineness, polyester and nylon, which are preferable materials for the water-absorbing material, require complicated technology and may not be preferable in terms of washing durability. .
Further, although the sea elution method using sea-island composite fibers can obtain fine fibers, it is not preferable because the processing steps are complicated and expensive. It is preferable that such a water-flow splitting composite fiber can be split and entangled with a water pressure as low as possible, but 50 kg / cm ² or more is required, and 50 kg / cm ²
If the amount is less than, a fiber that can be split with low water pressure is required, and the splitting occurs when the fiber is formed into an open sheet shape with a card machine or during the stretching process during raw cotton production, and cannot be a product. A maximum of about 250 kg / cm ² is not preferable because the fabric is too tight and the amount of voids is reduced.

The splittable conjugate fiber composed of two types of incompatible polymers, which are preferable for use in the present invention, will now be described.

The two incompatible polymers may be any combination of polymers that can be split by an external stimulus such as water flow, and are not particularly limited. For example, polyester-based and nylon-based, polyester-based Polymers generally used as splittable conjugate fibers such as polyolefin-based, polyester-based and polystyrene-based can be used.

Naturally, if it is a polyester type polymer,
Terephthalic acid, isophthalic acid, phthalic acid,
Aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid or aliphatic dicarboxylic acids such as adipic acid and sebacic acid or their esters and alcohol components such as ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, A homopolyester or a copolyester synthesized from a diol compound such as neopentyl glycol or 1,4 cyclohexanedimethanol, and these copolyesters are paraoxybenzoic acid, 5-sodium sulfisophthalic acid, polyalkyl glycol, penta Erythritol, bisphenol A, etc. may be added.

If it is a nylon polymer, nylon-4, nylon-46, nylon-6, nylon-
66, nylon-610, nylon-11, nylon-
12, polymeta-xylene adipamide (MXD-6), polyaraxylene decanamide (PXD-12), polybiscyclohexylmethane decanamide (PCM-12)
Alternatively, a copolyamide having these monomers as constituent units may be used.

Polyethylene, polypropylene, polybutylene and the like may be used as long as they are polyolefin type polymers.

Among these polymers, it is more preferable to use any one of polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate obtained by copolymerizing 5-sodium sulfoisphthalic acid as the polyester polymer, and nylon as the nylon polymer. Providing the ability to peel off with a water jet punch after that, because it is a short fiber and does not peel off with a card etc. probably because it has a moderate adhesiveness at the interface of both polymers in the split type conjugate fiber of the combination using 6 You can Furthermore, splittable conjugate fibers in which a polyester polymer is combined with polypropylene, polyethylene or the like are also preferable.

FIGS. 3, 4, and 5 are schematic model diagrams showing examples of the cross section of the composite fiber used in the water absorbing material used in the present invention. Two kinds of polymers 7 in which the splittable composite fiber is not compatible with each other are shown. And the polymer 8 are arranged. The shape of the composite fiber is not limited to these, and an appropriate type can be used.

In the water absorbent material of the present invention, it is preferable that a part of the composite fibers constituting the same is divided, and more preferably, 30% or more of the divided fibers among the fibers constituting the water absorbent material ( It is that the number ratio). The fineness of the synthetic fibers constituted by the division in this way is 0.0
It becomes 1 to 2 dtex, which further improves the water absorption performance.

It is preferable that the fibers constituting the cloth-like water absorbing material of the present invention have antibacterial properties. For example, in order to suppress the growth of Escherichia coli or Staphylococcus aureus, any substance having an antibacterial property such as an organic substance or an inorganic substance can be used, and a silver zeolite type, a metal type such as copper, piguanite, a quaternary ammonium salt, a carvalinide, an amphoteric interface. Organic compounds such as activators, alcohols, esters, sulfamides, carboxylic acids, pyridines, nitriles, polymers, phenols, metal salts and amino acids are also effective.
The means for applying the antibacterial agent is not particularly limited, but a method of kneading into the synthetic fiber and adhering it to the fiber surface together with the binder at the time of post-processing is preferable. As a method of evaluating antibacterial performance, there is a unified test method established by the New Functional Evaluation Council for Textile Products.

In the above-mentioned polymer, a matting agent, a pigment, a flameproofing agent, a deodorant, an antistatic agent, an antioxidant, an ultraviolet absorbing agent, a hydrophilic agent, etc. may be added to the above-mentioned polymer within a range not impairing the effects of the present invention. Appropriate additives may be added.

In the water absorbent material of the present invention, it is preferable that the independent cloth A is located on the surface layer of the cloth-shaped water absorbent material. When this independent cloth A is used as a diaper, it is usually used as a cloth on the side that is in direct contact with the skin, such as the pubic area or the buttocks, and the cloth that excreted excrement touches first. With such a structure, the wet feeling can be further reduced. Such an independent cloth A
Although any fabric such as woven fabric, knitted fabric, and non-woven fabric can be used, knitted fabric is preferable from the viewpoint of flexibility.

The material used for the independent cloth A used in the present invention is not particularly limited, and natural fibers such as cotton, hemp, wool and silk, chemical fibers such as rayon and acetate, polyester, polyamide and acrylic. , Polypropylene, synthetic fibers such as polyethylene may be used, but preferably fibers such as natural fibers and rayon have water absorbency in the fibers themselves, so it takes time to dry after washing, and the feeling of wetness tends to remain, Synthetic fibers such as polyester and polypropylene are preferred.

The independent cloth A used in the present invention preferably has a water absorption rate of 5 seconds or less. If it is longer than 5 seconds, the problem that water absorption is delayed and leakage tends to occur during practical use tends to occur. It is preferable that such water absorption performance is satisfied even after the industrial washing described above. In order to achieve this, it is also necessary to select a fabric structure, air permeability, and a durable water absorbing material, and by combining these, the effect can be further enhanced.

The independent fabric A used in the present invention preferably has a large air flow rate, and preferably 100 cc / cm ² /
It is more than sec. If it is less than 100 cc / cm ² / sec, the permeation of water may be impaired or the skin may be roughened due to dampness. It is better to have more, but if too much, the water-absorbent fabric layer may come into contact with the human body and become uncomfortable.
It is preferably up to about c / cm ² / sec.

In order to further reduce the discomfort caused by wetting, the independent cloth A of the present invention preferably has a fiber or structure in which the surface layer in contact with the skin is different from the other layers. For example, the surface layer is made of thick fibers to have a rough structure to facilitate the permeation of water, and the other layers are made of fine fibers to have a dense structure, and the water that comes into contact with the surface layer quickly passes through the surface layer. However, the other layer absorbs and diffuses this, so that the wet feeling is improved and at the same time, the moisture transfer is performed quickly.

As another means for avoiding the feeling of wetting, it is preferable to interpose a mesh-shaped cloth so that the cloth-shaped water absorbing material does not come into contact with the human body.

The independent cloth A is partially bonded to one surface of the cloth-shaped water absorbent material, but it may be bonded to the back surface which is the opposite surface to form a sandwich shape.

In order to further increase the absorption rate of the independent cloth A, it is preferable to add a water absorbing agent. By adding a water absorbing agent to improve the water absorbing speed, it is possible to further impart a dry feeling to the fabric surface.
Any water-absorbing agent may be used as long as it can reduce the surface tension of water, and examples thereof include silicone-based, polyester-based, and polyamide-based. It is generally said that the effect is more enhanced when a water absorbing agent of the same type as the surface cloth is used. It is effective to apply the solid content of 0.1% or more.

It is preferable that an independent cloth B having liquid impermeability is located on the back surface layer of the cloth-like water absorbent material of the present invention for the purpose of waterproofing.

The independent cloth B can be used in any form of woven fabric, knitted fabric, non-woven fabric, film and the like, and may be a laminate of these. That is, since it may be difficult to satisfy the liquid impermeability only with a woven fabric, a knitted fabric, or a nonwoven fabric, a rubber-based, polyolefin-based, fluorine-based, or silicone-based film-like material may be attached to these materials, or This can be achieved by coating a rubber-based, polyolefin-based, fluorine-based or silicone-based resin, preferably a foamed resin. In addition, water repellency can be imparted by adopting these configurations.

At that time, in order to improve the stuffiness caused by receiving urination, the moisture permeability of the independent fabric B is 4000 g.
/ M ² · 24 hours or more is preferable.

Further, in that case, durability as a film is required, and the water resistance of the independent cloth B is preferably 5.0 kPa or more. When it is less than 5.0 kPa, leakage may occur. These achievement techniques include textiles,
Base fabrics such as knits and non-woven fabrics are coated with, for example, porous polyurethane typified by "ENTRANT" (registered trademark of Toray Co., Ltd.) or porous fluorine typified by "GORE-TEX" (trademark of GORE-TEX). Adhesion of a film or the like can be used.

In the water absorbent material of the present invention, the independent fabric A
It is preferable that the water-absorbing material B independent of the cloth-like water-absorbing material is partially joined, and the peripheral portion or a part of the peripheral portion, and further a part of the inner surface are sewn by a method such as quilting. Good to do.

More preferably, the independent cloth A and the independent cloth B are formed to be larger than the cloth-like water absorbent material, the periphery of both cloths is sewn, and the cloth-like water absorbent material is put inside the sewn portion between them. This is a structure in which an independent cloth A and a cloth-like water absorbent are sewn in a quilted state.

More preferably, by having a horizontal leakage prevention structure, a gather structure is formed so that a part of the peripheral portion becomes a three-dimensional wall, and the edge of the water absorbent material and the skin are more easily adhered. That is.

It is preferable that the sewing thread at the time of performing such sewing is also treated with a water repellent agent such as a paraffin type, silicone type or fluorine type water repellant agent so as to easily absorb water.

FIG. 1 is a schematic cross-sectional model view showing an example structure of the water absorbent material according to the present invention, in which a part of the water absorbent material is shown in an easy-to-understand manner. ) 1 and a liquid impermeable independent fabric (B) 2
And the cloth-like absorbent material 3 disposed between these cloths A and B, and that they are partially joined by the sewing thread 4.

[0060]

EXAMPLES The present invention will be described in more detail below with reference to examples.

The evaluation method used in the present invention will be described. The evaluation method not described here basically conforms to the method defined by JIS. (1) Aeration rate: According to method A of JIS-L-1096 "General woven fabric test method". (2) Water vapor transmission rate: According to JIS-Z-0208 "Moisture transmission test method for moisture-proof packaging material". (3) Fineness of short fibers after division: An SEM photograph of the cross section of the fiber was taken and calculated from the cross sectional area. (4) Water absorption: According to method A (Bayrec method) of JIS-L-1096 "General textile test method". (5) Water absorption: According to JIS-L-1912 "Medical nonwoven fabric test method". (6) Moisture vapor transmission rate: According to JIS A method of A-1 of JIS-L-1099 "Test method for moisture vapor transmission rate of textile products" (7) Water pressure resistance: According to JIS-L-1092 "Water resistance test of textile products". (8) Amount of voids in the cloth-like water absorbing material: cloth 10 in the cloth-like water absorbing material
The void volume per 0 cm ² is expressed by the following formula.

[0062] void volume = (fabric 100 cm ² per volume) per fabric 100 cm ² - volume fabric per fabric 100 cm ² (the volume of the fibers constituting the fabric of 100 cm ^2), the thickness superimposed fabric water-absorbing material is A sample with a size of 5 cm or more and a size of 10 cm or more in the vertical and horizontal directions is first applied with a load of 10 g / cm ^{2 to} remove excess voids such as wrinkles, and then pre-compressed, and then 0.
Apply a load of 5 g / cm ² and measure the thickness and vertical / horizontal size, and divide by the number of stacked sheets to calculate.

Even when a plurality of layers of the water absorbing material are laminated to form one water absorbing material, the water absorbing material is used for the measurement as one water absorbing material. That is, in that case, the one water-absorbing material is used as one unit and they are stacked to have the above-mentioned thickness of 5 cm or more and the above-mentioned measurement is performed.

The volume of the fibers constituting the cloth per 100 cm ² is calculated from the specific gravity of a predetermined fiber by measuring the weight and the volume of the cloth. If the sample cannot take this area, the same measurement may be performed and then the conversion may be performed again. (9) Compressibility of cloth-like water absorbent material: The compressibility of the cloth-like water absorbent material was measured by stacking the cloth-like water absorbent material with a thickness of 5 cm or more as a sample, and at first 10 g / c to remove extra voids such as wrinkles.
After pre-compressing under a load of m ² , the thickness is measured under a load of 0.5 g / cm ² to be T1, and then the thickness is measured under a load of 10 g / cm ² and T2 is calculated by the following formula. calculate.

Compressibility (%) = (T1−T2) × 100 / T1 (10) Thickness of fabric-like water absorbing material: JIS-L-1913
According to Method B of "General Short Fiber Non-woven Fabric Test Method". (11) Antibacterial and deodorant performance: In accordance with the new functional evaluation committee for textile products.

Antibacterial and deodorant standard: bacteriostatic activity value = logB-logC
> 2.2 Number of inoculated bacteria: 1 ± 0.3 × 10 ⁵ / ml, log (B /
A)> 1.5 A: Number of bacteria recovered immediately after inoculation of unprocessed product (cotton or fabric) B: Number of bacteria recovered immediately after 18-hour culture of unprocessed product (cotton or fabric) C: Antibacterial processed product Number of bacteria recovered immediately after 18-hour cultivation of (cotton or fabric) Target strain: Staphylococcus aureus (ATCC
6538P) The washing method of the fiber structure is JIS L 0217 10
The number of times of washing was set to 10 by the method 3. (12) Industrial washing shrinkage rate: According to F-2 method (intermediate washer method) of JIS-L-1042 "Test method for shrinkage rate of textiles", water temperature is 80 ° C (constant), 1000 g of water, 2 g of detergent. Sodium percarbonate (1.5 g) and hydrogen peroxide solution (3 cc) were added, and the sample was put therein and treated for 30 minutes. Then, after rinsing with warm water of 40 ° C. for 10 minutes, centrifugal dehydration (using a centrifugal dehydrator of a domestic washing machine as a centrifugal dehydrator for 1 minute) is performed, and then 130 to 15
It was dried on a flat bed press at 0 ° C. This one
Repeated 0 times.

A length of 300 mm is marked on each of the vertical and horizontal sides of the sample in advance, and the length 1 after industrial washing is measured, and the shrinkage rate (%) = (300-l) / 300 × 100 And horizontal were calculated respectively.

In the present invention, when the mark applied after the washing treatment was blurred, the center was visually judged and the length after shrinkage (after industrial washing) was measured. (13) Water absorption rate of cloth: According to the dropping method of JIS-L-1907 "Test method for water absorption of textiles". (14) Degree of fabric division: SE of the target fabric cross section
M photograph (× 500-800) is taken, and at least one fiber A is peeled off at the cut surface of one fiber
And the number of fibers B that have not been completely peeled off are calculated, and the division ratio (%) = the number of fibers A / (the number of fibers A + the number of fibers B) × 100. Example 1 A composite fiber composed of a polymer of polybutylene terephthalate and nylon 6 and having a cross section as shown in FIG. 4, polymer 6 is polybutylene terephthalate, polymer 7 is nylon 6 and polymer 5 is in 6 regions. It is divided and arranged. This composite fiber has a composite fiber state of 1.8 dtex and an average fiber length of 38 mm. The composite fiber is applied to a card machine to open the fiber to form a sheet, and a plurality of such sheets are laminated and entangled with a water jet punch machine as a pre-punch at a water pressure of 20 kg / cm ² , and then a water pressure of 120 kg / cm ² Then, a non-woven fabric was prepared by passing the water flow through the front, back and front three times in total.

This non-woven fabric was cut into a width of 150 cm and a length of 7 m to prepare a cut non-woven fabric, and the non-woven fabric was repeatedly rotated in the normal state without any tension and was rotated at 90 ° C. with a drum-type hot water treatment machine. It was treated with warm water for 30 minutes. At this time, in an aqueous solution containing Lanogen KRN-6 (manufactured by Takamatsu Oil & Fat Co., Ltd.) and TO-SR-1 (manufactured by Takamatsu Oil & Fat Co., Ltd.) in hot water so that the amount of adhesion when dried was 2% by weight with respect to the nonwoven fabric. I put it in

Then, dry heat at 100 ° C. in a tumbler dryer.
And dried for 30 minutes. This non-woven fabric has a basis weight of 220 g / m
^When the cross section of this non-woven fabric was observed with a SEM photograph in ² , the composite fiber was divided from the interface of polybutylene terephthalate and nylon 6. The splitting ratio was 62%, and the fineness of the single fiber after splitting was 0.2 dtex for the nylon 6 portion and 0.6 dtex for the polybutylene terephthalate portion.

Six pieces of this non-woven fabric were stacked and cut into a width of 25 cm and a length of 60 cm to obtain a cloth-like water absorbent material of the water absorbent material of the present invention.

Polyester yarn 55 as an independent fabric A
Using two types of threads, dtex, 12 filaments and 55 dtex, 46 filaments, a knitted fabric was prepared by knitting with the tricot knitting machine so that the former is on the back side and the latter is on the front side. A polyester water absorbing material was applied to the knitted fabric so that the weight ratio thereof was 0.5%.

As an independent cloth B, a waterproof cloth was prepared by adhering a 10 μm-thick polyurethane film to a cloth made of polyester using polyester thread.

The independent cloth A and the independent cloth B were cut into a substantially gourd shape. A portion corresponding to a gourd-shaped neck that fits the crotch is cut into a width of 30 cm and a length of 60 cm, and the water-absorbent material of the present invention is laminated between them. First, the top sheet and the water-absorbent material are surrounded by polyester multifilament yarn 20 cotton. The count is partially joined by using a sewing thread to which 0.5% of a fluorine-based water repellent is added, and further the four peripheral areas are sewn and integrated by using the sewing thread using the top sheet and the back sheet first, and the invention is integrated. I made a diaper.

The water absorbing material had a thickness of 5 mm and was soft and comfortable to wear. It also absorbs 200 cm ³ of water,
When the wet surface was pressed with a hand after 5 minutes, the surface of the hand was free from moisture and was free-flowing. Example 2 A polyethylene terephthalate fiber having a fineness of 2 dtex, a fiber length of 38 mm, and an H-shaped cross section was opened by a card machine to prepare a sheet, and a plurality of such sheets were laminated, and then pre-punched by a water jet punch machine. After being entangled at a water pressure of 20 kg / cm ² , a non-woven fabric was prepared by passing a total of 3 times of water flow on the front and back sides at a water pressure of 120 kg / cm ² .

The nonwoven fabric was processed in the same manner as in Example 1 to obtain a nonwoven fabric having a basis weight of 220 g / m ² . A water absorbing material of the present invention was prepared by processing in the same manner as in Example 1 except that this non-woven fabric was used as a cloth-like water absorbing material. Comparative Example 1 Using the same fibers as in Example 1, a nonwoven fabric was prepared by performing the same processing as in Example 1 except that heat treatment was performed at 90 ° C. in warm water and drying at 100 ° C. was performed. A water absorbing material was prepared using the same material as in Example 1 except that this non-woven fabric was used as the cloth-like water absorbing material. Comparative Example 2 Polyester fiber 3.3 dtex, 51 mm single component raw cotton was opened by a carding machine to form a web, and a plurality of the webs were laminated and the fibers were entangled with a needle punch machine to form a nonwoven fabric. This nonwoven hard cotton had a thickness of 2 mm and a density of 0.04.

A diaper was prepared under the same conditions as in Example 1 except that a material obtained by cutting three non-woven fabrics each having a width of 25 cm and a length of 60 cm was used as a water absorbing material, and a cotton cloth was used as a top sheet. Comparative Example 3 A diaper was prepared under the same conditions as in Example 1 except that cotton cloth was used as the water absorbing material. At that time, the fabric weight after the hot water treatment was 160 g / m ² and eight sheets were piled up to obtain a cloth-like water absorbent material.

[0078]

[Table 1]

Table 1 shows the properties and performances of Examples and Comparative Examples.

As a result of being practically used as a diaper, the product of the present invention and Comparative Example 1 did not feel wet and could be used without moisture stains even when seated while wet, whereas Comparative Examples 2 and 3 Leakage occurred, and when seated, the exudation was severe and the wet feeling was considerable. Further, the products of the present invention have little washing shrinkage and can be put to practical use even in severe washing performed by a trader, but in Comparative Examples 1 and 3, all of the absorbents have large shrinkage and cannot be put to practical use.

[0081]

According to the present invention, excellent absorption is exhibited,
Further, it is possible to obtain a water absorbent material which has little wet feeling and is excellent in industrial washing durability.

Further, the water-absorbent material of the present invention does not leak water when used, does not feel wet, and can be used comfortably even if it is placed on a seat without causing moisture stains, and can be repeatedly washed by a laundry company. It is economical because it can be done.

[Brief description of drawings]

FIG. 1 is a schematic model cross-sectional view showing an example structure of a cloth-like water absorbent used in a diaper according to the present invention.

FIG. 2 is a schematic model view showing an example of the cross-sectional shape of the fibers used in the cloth-like water absorbent used in the water absorbent according to the present invention.

FIG. 3 is a schematic model diagram showing an example of a cross-sectional shape of a splittable conjugate fiber (raw cotton) used in a cloth-like water absorbent used in the water absorbent according to the present invention.

FIG. 4 is a schematic model diagram showing another example of the cross-sectional shape of the splittable conjugate fiber (raw cotton) used in the cloth-like water absorbent material used in the water absorbent material according to the present invention.

FIG. 5 is a schematic model view showing another example of the cross-sectional shape of the splittable conjugate fiber (raw cotton) used in the cloth-shaped water absorbent material used in the water absorbent material according to the present invention.

[Explanation of symbols]

1: Cloth-like water absorbent 2: Independent fabric A 3: sewing thread 4: Independent fabric B 5: Polymer 6: Polymer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) D06M 15/507 A41B 13/02 S (72) Inventor Tomoshige Sugino 1-1-1, Sonoyama, Otsu City, Shiga Prefecture No. Shiga Shokusan Co., Ltd. (72) Inventor Shinji Sano 1-6-20 Dojima, Kita-ku, Osaka City Toray Co., Ltd. Osaka Plant (72) Inventor Taizo Horiike 1-6-20 Dojima, Kita-ku, Osaka Toray Incorporated in Osaka business (72) Inventor Koichi Saegusa 1-6-20 Dojima, Kita-ku, Osaka Toray F-term in Osaka business (Reference) 3B029 BF03 BG00 4C098 AA09 CC03 DD04 DD05 DD06 DD07 DD10 DD19 DD23 DD24 DD25 DD26 DD28 4L033 AA07 AA08 AB07 AC07 CA45 4L047 AA21 AA23 AA27 AA29 AB02 AB08 BA04 CA04 CA06 CB07 CB10 CC01 CC04 CC06

Claims (22)

[Claims] 1. A fabric-like water-absorbing material comprising fibers, which comprises 10
The void volume per 0 cm ² is 10 cc or more, and the thickness is 1 mm
It is characterized in that the shrinkage rate of the vertical or horizontal after 10 industrial washings is 6% or less, and the main fiber constituting the fabric-like water absorbent is a synthetic fiber having a fineness of 0.01 dtex to 2 dtex. Water absorbent material. 2. The cloth-shaped water-absorbing material is formed by adhering a water-absorbing agent to the surface of the constituent fibers of the cloth-shaped water-absorbing material, and the water-absorbing capacity of the cloth-shaped water-absorbing material measured by the Bayrek method is 50 mm or more. The water absorbing material according to claim 1, wherein 3. The water absorbing material according to claim 1, wherein the water absorbing material of the cloth-like water absorbing material has a water absorption of 100% or more. 4. The water absorbent material according to any one of claims 1 to 3, wherein the cloth-like water absorbent material is a non-woven fabric having a compressibility of 30% or less. 5. The water absorbing material according to any one of claims 1 to 4, wherein the fabric-like water absorbing material has a basis weight of 500 g / m ² or more. 6. The fiber constituting the fabric-shaped water absorbing material is a composite fiber as a starting material, and a part of the composite fiber is divided by a water pressure treatment of 50 kg / cm ² or more. The water absorbent material according to any one of claims 1 to 5. 7. The water absorbing material according to any one of claims 1 to 6, wherein 30% or more of the fibers are divided among the fibers constituting the fabric water absorbing material. 8. The water absorbent material according to claim 1, wherein the synthetic fibers constituting the cloth-like water absorbent material have antibacterial properties. 9. The water-absorbing material according to claim 1, wherein the cloth-like water-absorbing material has a plurality of layers of the same kind laminated on each other. 10. The water-absorbing material according to claim 1, wherein the cloth-like water-absorbing material is composed of a plurality of layers in which the constituent fibers have different fineness. 11. The water absorbent material according to any one of claims 1 to 10, wherein an independent cloth A is located on the surface layer of the cloth-like water absorbent material. 12. The independent cloth A is characterized in that the fineness of the fibers which are mainly constituted in the thickness direction is different, and the surface which is in contact with the cloth-shaped water absorbing material is made of finer fibers. 11. The water absorbent material according to any one of 1 to 11. 13. The water absorbent material according to any one of claims 1 to 12, wherein the water absorption rate of the independent cloth A is 4 seconds or less. 14. The independent water absorption rate of the cloth A is 1 for industrial washing.
The water-absorbing material according to any one of claims 1 to 14, which is 5 seconds or less after 0 times. 15. The water-absorbing material according to claim 1, wherein an independent cloth B having liquid impermeability is located on the back surface layer of the cloth-like water-absorbing material. 16. The water absorbent material according to any one of claims 1 to 15, wherein the water impermeable independent fabric B has a water pressure resistance of 5.0 kPa or more. 17. The water absorbent material according to any one of claims 1 to 16, wherein the liquid impermeable independent fabric B has a moisture permeability of 4000 g / m ² · 24 hr or more. 18. An independent cloth A, an independent cloth B, and a cloth-like water absorbent material arranged between these cloths are joined by a sewing means, and a sewing thread used for the sewing is made water repellent. The water-absorbing material according to any one of claims 1 to 17, wherein 19. The water absorbing material according to claim 1, wherein the water absorbing material is used for diapers. 20. A cloth-shaped water-absorbing material made of fibers is heat-treated,
The fabric-like water-absorbent material is heat-shrinked, the void amount per 100 cm ^{2 of the} cloth-like water-absorbent material is 10 cc or more, the thickness is 1 mm to 20 mm, and the shrinkage ratio of vertical or horizontal after 10 industrial washings. Is 6% or less, and the fineness of the main fibers constituting the cloth-like water absorbent is from 0.01 dtex to 2 d.
A method for producing a water-absorbing material, comprising obtaining a cloth-like water-absorbing material which is tex. 21. The method for producing a water absorbing material according to claim 20, wherein the heat treatment is performed by treating the fabric water absorbing material with warm water of 80 ° C. or higher. 22. The method for producing a water absorbent material according to claim 20 or 21, wherein the cloth-like water absorbent material is contracted during the heat treatment without substantially applying tension.