JPS6018173A - Absorbing material for sanitary treatment - 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 The present invention relates to a menstrual blood absorbing material for sanitary treatment products. More specifically, the present invention relates to a menstrual blood absorbent material that has an excellent menstrual blood absorption function and has good elastic recovery properties even after menstrual blood absorption.

Conventional sanitary care products consist of menstrual blood absorbing material, waterproof paper to prevent the menstrual blood absorbed by the menstrual blood absorbing material from seeping into clothing, and the mechanical strength of the absorbent material decreasing after absorbing the liquid. It consists of covered paper to reinforce the material, adhesive tape for adhesion to clothing, etc.

The menstrual blood absorbing materials (hereinafter referred to as absorbent materials) used in conventional sanitary care products include absorbent cotton made by defatting fluff, rayon staple cotton made from recycled fibers made from vegetable fibers, and chemical pulp. It is constructed by forming absorbent paper, etc., into sheets, and laminating one type or two or more types of these sheets. Recently, starch-based, cellulose-based, synthetic polymer-based (polyacrylic acid-based, polyvinyl alcohol-based)
Natto's various super absorbent resins are made into powder or sheet form and are laminated in the middle part of the above-mentioned absorbent material. In addition, some RTC absorbers have activated carbon attached to them for deodorization.

Conventional absorbent materials have a multilayer structure as described above, and the order of lamination is usually determined depending on the main function performed by each sheet-like material. For example, the outer layer is usually laminated with two or more layers of absorbent cotton, rayon stable cotton, chemical pulp paper, etc. that have a high liquid absorption rate, and the interior is laminated with a super absorbent resin that has good liquid retention.

However, such conventional absorbent materials have the following drawbacks.

When the sheet-like materials used as materials for omega-absorbing materials, such as absorbent cotton, rayon stable cotton, chemical pulp paper, and superabsorbent resin, absorb menstrual blood, their elastic recovery function is extremely reduced and their mechanical strength is also reduced. Therefore, when pressure is applied after liquid absorption, the liquid does not return to its pre-pressurized shape, and the liquid absorption performance decreases.As the volume decreases, water channels are formed, which can cause leakage.Moreover, if the applied force is large, The absorbent material itself is torn and no longer performs its function.

b) Since the absorbent material has a multilayer structure and functions are divided in the thickness direction, the functions continue in the thickness direction, which is the liquid absorption path. For example, if there is a material with a high liquid absorption rate in the outer layer and a material with good liquid retention properties inside, after the outer layer begins to absorb menstrual blood, the material with good liquid retention properties in the inner part It takes time for it to function properly, and by the time the internal material begins to exhibit its liquid-retaining properties, the outer layer material has absorbed a considerable amount of menstrual blood, and the liquid absorption rate slows down. Put it away. It is undesirable for an absorbent material to not fulfill multiple functions at the same time.

C) Materials that absorb water quickly, such as absorbent cotton, rayon stable cotton, and chemical pulp paper, which are usually laminated on the outer layer of absorbent materials, generally have poor liquid retention properties when pressurized. There is a risk of menstrual blood seeping out.

When super absorbent resin is laminated in powder or sheet form, this resin becomes paste-like when it absorbs menstrual blood, but since one layer of the laminated structure becomes paste-like intensively, when pressure is applied, it becomes paste-like. This paste-like resin protrudes from the absorbent material and causes leakage.

e) In order to form the absorbent material into a multilayer structure, various materials must be laminated in the correct order, which complicates the manufacturing process.

Therefore, the inventors conducted intensive studies with the aim of providing an absorbent material that does not have the above-mentioned drawbacks, and as a result, they came up with the present invention.

That is, the present invention provides an absorbent for physiological treatment comprising a nonwoven fabric made from a mixture of at least two or more types of fibers that satisfies the three functions of fast liquid absorption rate, large liquid retention capacity, and good elastic recovery properties. It is related to materials.

The nonwoven fabric that is the absorbent material of this invention contains fibers with good elastic recovery properties and shows good elastic recovery properties even after liquid absorption, so the absorbent material does not return to its original shape after compression deformation. There is no risk of leakage of menstrual blood. Furthermore, fibers with good elastic recovery properties usually have excellent mechanical strength, and the mechanical strength does not decrease even when the absorbent absorbs liquid. For this reason, there is no need for covering paper as a reinforcing material unlike in conventional sanitary care products.

In addition, since the nonwoven fabric is made by combining at least two types of fibers and uniformly mixing them to satisfy the three functions mentioned above, which are important functions for absorbent materials, any part of the absorbent material can fulfill these three functions. This is satisfactory, and since the functions are continuous in the thickness direction of the absorbent material, each function is efficiently performed.

Furthermore, there are no materials that have poor water retention properties when pressurized, and even when fibers made of these materials are mixed in, these fibers are uniformly dispersed in the absorbent material and the surrounding area is Since the fibers retain a large amount of liquid even under pressure, menstrual blood will not leak even if pressure is applied while the absorbent material absorbs liquid. Furthermore, since the superabsorbent resins are not localized, these resins do not become paste-like and ooze out.

Furthermore, although the absorbent material of the present invention is made of a nonwoven fabric, conventionally known methods can be applied to produce the nonwoven fabric, and the manufacturing process is simple.

The absorbent material of this invention is made by combining fibers that have at least one of the following three functions: high liquid absorption rate, large liquid retention capacity, and good elastic recovery so as to satisfy the above three functions. The nonwoven fabric is a mixture of at least two types of fibers, and the following fibers may be used.

First, examples of fibers whose main function is to have a high liquid absorption rate include cotton yarn made from defatted fluff, rayon, etc., and the thickness of these fibers is usually 1 to 20 deniers, preferably 3 to 7 deniers. The length is usually 20 to 1
50 mm, preferably 40 to 70 mm is appropriate. These fibers usually have a liquid-retaining property that absorbs about 10 to 30 times their own weight of water, and the liquid absorption rate is 70% of the equilibrium water absorption when these fibers are made into a nonwoven fabric. It has a sand weight of about 0.01 to 1.

Next, examples of fibers whose main function is to retain a large amount of liquid include fibers whose surfaces are coated with a superabsorbent resin. This super absorbent resin quickly absorbs menstrual blood and swells, but it does not separate from the core fiber.
In addition, even if pressure is applied while the liquid is absorbed, menstrual blood does not seep out, and it has excellent liquid retention properties when pressurized. The amount of liquid retained by the fibers is preferably one that can absorb 09% saline, which is approximately equivalent to menstrual blood, about 40 to 50 times its own weight, and water about 90 to 100 times its own weight.

Preferred examples of such thick fibers include highly water-absorbent fibers such as EXLAN WAF and Lanseal (both trade names manufactured by Nippon EXLAN Co., Ltd.), which are made by coating the surface of acrylic fibers with acrylic acid-based super absorbent resin. I get kicked. This Lanseal can absorb about 150 times its own weight in water, and in 09% saline, which is approximately equivalent to menstrual blood, it can absorb 50 to 60 times its own weight. Also, it takes about 30 seconds to reach 70% of the equilibrium water absorption (1). The dry strength of this Lanseal is 1.2 to 25 y/denier and pH
is 7 to 6, and in terms of human safety, it meets the Ministry of Health, Labor and Welfare notification No. 2.
It has passed the No. 85 "Sanitary Treatment Product Standards" and has good processability.

The thickness of such super absorbent fibers is usually 15 to 20
The appropriate denier is l, preferably 3 to 5 denier, and the appropriate length is usually 20 to 200+++++++', preferably 30 to 60M.These fibers may have elastic recovery depending on the type of core fiber. For example, the core fiber of Lanseal is made of acrylic, so it also has elastic recovery properties.

Next, examples of fibers whose main function is good elastic recovery include polyester, nylon, polypropylene, etc., which are synthetic fibers characterized by low hygroscopicity and low water absorption. The elastic recovery properties of these fibers are determined by the elastic recovery force measurement method specified in JIS (sample length 25-50 cm).
m, tensile speed: 30 am, 1 minute, fixed at 3-4% elongation for 1 minute, weight removed, and recovery elongation measured after 1 minute] is preferably about 80-100%.

This elastic recovery property increases as the thickness of the fiber increases, but it is usually 1 to 20 deniers, preferably 3 to 7 deniers, and the length of the fiber is usually 20 to 150;+a, preferably 40 to 70 ttrm. is appropriate.

In addition, by treating the surface of these fibers with good elastic recovery with an emulsified glycerin fatty acid ester with a nonionic surfactant, these fibers are given liquid absorbency to the extent that elastic recovery is not indicated on the label. That is, it is also possible to increase the liquid absorption rate and impart liquid retention properties.

The absorbent material of the present invention satisfies the three functions of high liquid absorption speed, large liquid retention capacity, and good elastic recovery properties. It is usually obtained by selecting two or more types of A fibers and uniformly mixing appropriate amounts to form a nonwoven fabric. In addition, satisfying the above three functions here means that
This nonwoven fabric can reach 70% of its equilibrium water absorption capacity in about 30 to 60 seconds, and absorbs about 20 to 25 times its own weight (about 25 to 30 times its weight in water) of 09% saline, which is approximately equivalent to menstrual blood. ) can be absorbed, and this non-woven fabric is 100%
When absorbing liquid, apply a load of approximately 50 fi'/cnf to approximately 5
This means that the elastic recovery rate after being applied for minutes is 75-90%.

The mixing ratio of fibers to obtain such a nonwoven fabric is usually such that fibers whose main function is to have a high liquid absorption rate are
-80% by weight, 10-50% by weight of fibers whose main function is to have a large amount of liquid retention, and 10-50% by weight of fibers whose main function is to have good elastic recovery. It is preferable to mix it so that it becomes 10-80 weight%.

Next, to produce a nonwoven fabric from a mixture of these fibers,
Any method commonly known as a method for producing nonwoven fabrics can be applied. Note that the nonwoven fabric referred to here is one made by mechanically, thermally, or a combination of these, binding and bonding the fibers of a dry web (a thin film in which fibers are intertwined to form a spider web). It refers to something made into cloth without being woven on a loom.

This non-woven fabric is manufactured by, for example, a method of spraying using air, a method using a paper machine using water like paper, a method using a skim machine, etc.
A web of m thickness is formed and then this web is bonded and glued. Methods for this bonding and adhesion include a binder method in which adhesive is used to fix the material by dipping, spraying, etc., a melting method in which hot-melt fibers are mixed in, and the material is melted and bonded.
There is a needle punching method in which the web is repeatedly punctured with a barbed needle. Among these methods, a method using a skimming machine is preferable for forming a web, and a needle punching method is preferable for bonding and bonding this web.

In this needle punching method, the web is pierced with a barbed needle, and the fibers caught on the tip of the needle or the barbs are pushed in and the fibers become entangled with each other, creating a bond. The fiber arrangement becomes a three-dimensional arrangement, and the continuous connection of functions in the thickness direction of the web becomes even stronger. In addition, the thickness, hardness, and strength of the nonwoven fabric can be changed by changing the number of times of needle punching, the shape of the needle, the piercing angle, etc. When needle punching is performed at a number of punching times of 50 to 100 times/c1i, a nonwoven fabric having a bulk specific gravity of 0.01 to 0.3 y/cc and a thickness of 3 to 20 mm can be obtained.

In addition, this needle punching method has a long track record in the textile industry, and there are no problems with manufacturing technology and the manufacturing process is simple. It can be manufactured automatically at a speed of 2 to 3 m/lJ for a width of 1 to 2 m with a certain number of punching operations, which is also advantageous in terms of economy.

Of course, other bonding and adhesion methods can also be applied.For example, in the binder method using adhesives, rubber latex, polyacrylic ester, and vinyl acetate-acrylic ester copolymer having hydrophilic groups such as carboxyl groups and hydroxyl groups are used as the adhesive. , acrylic acid ester-vinyl chloride copolymer, polyurethane, etc. are preferable because the liquid absorbency is not inhibited.

The shape of the non-woven fabric as an absorbent material of the present invention obtained in this way usually has a thickness of about 3 to 10+++ m and a basis weight of 50 to 500 fj/tr? , preferably 1
Approximately 50-2502/f7f, bulk specific gravity 001-01
It is assumed to be approximately y/cc.

The surface of this nonwoven fabric is coated with 50 to 50 hydrophilic short fibers with a length of 10 mm or less in order to reduce the contact area with the human body, reduce the feeling of wetness, and increase the rate of liquid absorption.
Electrostatic flocking may be performed at a flocking density of 2509/nf.

Examples of this invention are shown below. In addition, in the following, parts mean parts by weight.

Example 1 Absorbent cotton thread (thickness 20 denier, length 3' Omm) 5
5 parts, super absorbent fiber (Lanseal manufactured by Nippon Exlan Co., Ltd.;
10 parts of polyester fiber (10 denier in thickness, 35 tnm in length) and 35 parts of polyester fiber (Tetron, manufactured by Kijinsha; 10 denier in thickness, 150 mm in length) were mixed uniformly,
Come out of the card machine (skip machine) (ru1)
00μm thick webs were laminated to a thickness of 5am, and the shape was 500XI 000tnm (total weight 100g), and a rubber solid content of 100p/η was made using styrene-butadiene rubber latex into which carboxyl groups were introduced as an adhesive.
After spraying with a sprayer so that the temperature is 80-90°C
Dry with hot air for 30 minutes to obtain a thickness of 4 and a non-woven fabric weight of M.
200? /n? A nonwoven fabric with a bulk specific gravity of 0.1009/cc was obtained and used as an absorbent material.

Example 2 35 parts of L/-yon yarn (thickness: 2 denier, length: 50 mm), 50 parts of super absorbent fiber (Lanseer, manufactured by Nippon Exlan Co., Ltd.; thickness: 5 denier, length: 200 m), and polypropylene (thickness: 3 denier) , length 301 nm) were uniformly mixed and laminated to form a web that came out of the docker of a card machine to a thickness of 50 μm and 50 μm thick.
A shape of 0X1000+o+ (total weight ff1loo y) was formed, and needle punching was performed using 50 punches/d1 vertical up and down needle punching to a thickness of 4.5.
mm, measuring amount 200? /nZ+, bulk specific gravity 0.045
A nonwoven fabric of f;'/cc was obtained and used as an absorbent material.

Example 3 Super absorbent fiber (Lanseal manufactured by Nippon Exlan Co., Ltd.: thickness 3
Example 2 Needle punched in the same manner as above to obtain a thickness of 151 nm and a basis weight of 30.
A nonwoven fabric with a bulk specific gravity of 0.07/nf and a bulk specific gravity of 0.07/nf was obtained and used as an absorbent material.

Regarding the absorbent materials of Examples 1 to 3 above, the amount of liquid absorbed, the rate of liquid absorption,
The results of investigating the liquid retention rate and elastic recovery rate during processing are shown in the table below.

Note that the measurements in the above table were performed as follows.

Amount of liquid absorbed: A sample of absorbent material with a size of 5 Q x 50 mm was added to 200 cc of 0.9% saline solution.
Immerse the sample in a beaker with water so that the bottom surface is 20 mm deep, leave it for 5 minutes, take it out, leave it on a 10-mesh wire mesh for 1 minute, measure the weight of the sample, and calculate this value before water absorption. Divided by the sample weight.

Liquid absorption rate: Use an absorbent material with a size of 50 x 50 ytun as a sample, combine this sample with a 10 mesh wire mesh of the same size, and place the sample in a beaker containing 200 cc of 09% saline with the wire mesh side facing up. The bottom surface is 20tnm deep
Dip it in the water for 10 seconds, then take it out.
The weight of the sample was measured after being left on a 10-mesh wire mesh for 1 minute, and this value was divided by the weight of the sample before water absorption.

Liquid retention rate and elastic recovery rate during processing; absorbent material 50X 50
Using a sample with a size of Place a 5X70X70 glass plate on top of the sample, and the load applied to the sample including this glass plate will be IK.
g and leave it for 5 minutes. Next, the thickness and weight of the sample were measured 10 seconds after the load was removed. Divide the weight at this time by the previously measured weight before applying the load to determine the liquid retention rate during processing, and divide the thickness at this time by the previously measured thickness before applying the load to determine the elastic recovery rate. I met.

Patent applicant: Nitto Electric Industry Co., Ltd.

Claims (3)

[Claims] (1) An absorbent material for physiological treatment consisting of a nonwoven fabric manufactured from a mixture of at least two or more types of fibers that satisfies the three functions of high liquid absorption rate, large liquid retention capacity, and good elastic recovery. (2) The mixture of fibers consists of 0 to 80 wt% fibers whose main function is to have a high liquid absorption rate, 10 to 50 wt% fibers whose main function is to have a large liquid retention capacity, and fibers whose main function is elastic recovery. The absorbent material for physiological treatment according to claim 11, comprising 10 to 80% by weight of fibers having good properties. (3) The absorbent material for physiological treatment according to claim (1) or (2), wherein the nonwoven fabric is manufactured by a needle punching method.