JPH09276331A - Absorbent material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent material which is suitable to use as a sanitary material for its dissolving property in water at ambient temperature. This property enables the absorbent material to use and flush in a flush toilet without a plugging problem. SOLUTION: This absorbent material is non-woven fasbric consists of 100-30wt.% water-disintegrable fibers and 0-70wt.% thermoplastic fibers. The water-disintegrable fibers are reeled out from a dissolved water-disintegrable compound which is a copolymer consists of a starch-based high molecular compound and a copolymer after partly processed by hydrolysis. The copolymer after partly processed by hydrolysis consists of vinyl acetate and unsaturated monomer without a functional group.

Description

Detailed Description of the Invention

[0010]

TECHNICAL FIELD The present invention relates to absorbent articles. Specifically, it does not collapse when exposed to a small amount of water,
The present invention relates to an absorbent article that disintegrates when dropped in water. More specifically, it relates to an absorbent article such as a disposable diaper or a sanitary napkin that can be disposed of in a flush toilet when used as an absorbent article.

[0011]

BACKGROUND ART Disposable diapers and sanitary napkins are widely used in the world because they are inexpensive and can be easily used. However, there is a big problem in processing after use. That is, diapers and napkins with bodily fluids and excretions are discarded at the same time as general waste. Occasionally, an offensive odor may drift from the disposal site, which is unsanitary and causes environmental degradation. Furthermore, there are still problems with the treatment after collection. The usual disposable diapers, which are mainly composed of non-degradable chemical fibers, do not decompose in the soil, so even if they are disposed of by landfill or the like, they are left indefinitely and are normally incinerated at a garbage disposal site. . At this time, the combustion heat of diapers and napkins, which are mainly composed of chemical fibers, becomes high temperature, which may damage the furnace, and the solution has been delayed.

As one means for solving these problems, a method of using biodegradable fibers such as polycaprolactone, polylactic acid, and aliphatic polyester instead of non-degradable chemical fibers as a surface material for absorbent articles has been studied. ing. For example, Japanese Patent Application Laid-Open No. 7-126970 discloses a biodegradable non-woven fabric using fibers made of biodegradable polylactic acid and / or a thermoplastic resin containing polylactic acid as a main component. The purpose is to dispose of the absorbent article after use by landfilling it, decomposing it with microorganisms, and returning it to the natural world. However, in the current waste treatment, even if the absorbent article is composed of a biodegradable composition, there is no disposal method of separating it from ordinary waste and composting it, and as a result, it is incinerated. Is not an efficient process.

As another solution, a study has been made on making a diaper that can be disposed of in a flush toilet. In the United States, after using a diaper, a disposable diaper having a structure that can be removed so that it can be flushed in the toilet is commercially available. When such a diaper is used, the problem of offensive odor caused by the accumulation of dirty diapers does not occur, and there is no fear of damaging the furnace of the incinerator. However, even if the absorbent is flushed into the toilet, if the opening of the absorbent in water is slow, the composition becomes a bead and the toilet may be clogged.

[0014]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above problems, the present inventors have obtained a conventional absorbent article by using a special water-disintegrating fiber. The property that could not be achieved, that is, the absorbent article has the ability to quickly disintegrate with water at room temperature, so even if it is thrown into the toilet as it is, it will not be clogged and it will be possible to obtain a water absorbent article that can be disposed of. The present invention has been completed. The purpose of the present invention is to dispose of in normal temperature water,
It is an object of the present invention to provide an absorbent article suitable for a sanitary material that can be made into different constituent materials for the absorbent article and can be treated without clogging even when flushed to a flush toilet.

[0015]

The present invention has the following configuration. (1) Water-disintegrating fiber obtained by melt spinning a water-disintegrating composition comprising a starch-based polymer compound and a copolymer obtained by partially hydrolyzing a copolymer of vinyl acetate and an unsaturated monomer having no functional group. 100 to 30% by weight and thermoplastic fiber 0 to 7
An absorbent article using a non-woven fiber aggregate composed of 0% by weight. (2) The unsaturated monomer containing no functional group is at least one selected from ethylene, propylene, isobutylene and styrene, and the saponification degree of the partially hydrolyzed copolymer is 78 to 98%, and The absorbent article according to item (1), wherein the content of the decomposition copolymer is 30 to 70% by weight. (3) The non-woven fiber aggregate was used as a surface material (1)
The absorbent article according to Item. (4) The non-woven fiber aggregate was used as an absorbent material (1)
The absorbent article according to Item. (5) The absorbent article according to item (1), wherein the thermoplastic fiber is a heat-fusible composite fiber.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The absorbent article of the present invention comprises a liquid-permeable surface material layer, a liquid-impermeable backsheet layer, and an absorbent material between the surface material layer and the backsheet layer. However, the present invention is not limited to these configurations, and a single n layer or a plurality of layers may be additionally inserted between these layers. Such an additional insertion layer has a function of controlling the rapid transfer of the body fluid to the absorbent material, a function of preventing the body fluid from returning, and the like.
The surface material has sufficient liquid permeability, and a knitted woven fabric, a non-woven fabric, a porous film, a composite material of these, or the like can be selected and used according to a wide variety of performance requirements. The backsheet is a liquid-impermeable sheet, preferably a vapor-permeable sheet that allows vapor to permeate, and preferably uses a material that is soluble by a large amount of water. Alternatively, a composite of a nonwoven fabric and a sheet can also be used. When the additional insertion layer is provided with a function of promoting the diffusion of the liquid, a tissue or the like can be used.

The absorbent generally has a composition in which pulp fibers and a superabsorbent polymer are uniformly mixed, but in order to retain the mold when wet with water, it is used as a water-soluble binder which is water-disintegratable as described later. You can also mix fibers. The pulp fiber is not particularly limited as long as it is conventionally used as an absorbent material. The superabsorbent polymer is not particularly limited as long as it has been conventionally used for a water absorber, for example, starch-acrylic acid graft polymer, polyacrylic acid sodium cross-linked product, isobutylene-maleic anhydride copolymer or The saponified product, PVA cross-linked product, polyacrylic acid salt and the like can be used.

One of the materials of the water-disintegrating fiber used in the present invention
Examples of the starch-based polymer compound used as a seed include syrup-starch starch, bracken starch, kudzu starch, potato starch, wheat starch,
Illustrative examples include homogeneous melts having at least one kind of heat-modified thermoplastic material such as kissaba starch, sago starch, tapioca starch, syrup, bean starch, lotus starch, histo starch, and sweet potato starch. The heat denaturation is performed with 60 to 300 M of starch containing 5 to 30% by weight of water while maintaining the water content in a closed space.
It is processed by heat treatment at 80 to 290 ° C. under a high pressure of Pa. Other starch-based polymers include chemically modified starch derivatives (allyl etherified starch, carboxymethyl etherified starch, hydroxyethyl etherified starch,
Hydroxypropyl etherified starch, methyl etherified starch, phosphoric acid crosslinked starch, formaldehyde crosslinked starch, epichlorohydrin crosslinked starch, acrolein crosslinked starch, acetoacetic acid esterified starch, acetic acid esterified starch, succinic acid esterified starch, xanthogenic acid Esterified starch, nitrate esterified starch, urea phosphate esterified starch, phosphate esterified starch), chemically modified starch (dialdehyde starch, acid treated starch, hypochlorite oxidized starch, etc.), enzyme modified starch (hydrolyzed starch) Degraded dextrin, enzyme-degraded dextrin, amylose, etc. Physically modified starch (α-starch, fractionated amylo-
However, heat-modified starch is most preferable from the viewpoint of melt extrusion processability.

Further, a copolymer obtained by partially hydrolyzing a copolymer of vinyl acetate used as another type of the water-disintegratable fiber used in the present invention and an unsaturated monomer having no functional group (hereinafter referred to as partial hydrolysis). (Abbreviated as a decomposition copolymer),
It is a copolymer obtained by copolymerizing vinyl acetate and an unsaturated monomer having no functional group such as ethylene, propylene, isobutylene or styrene, and hydrolyzing the ester group. The saponification degree of the polymer is 78 to 98%, more preferably 85 to 98%, and further preferably 90 to 9%.
8%. The content of the partially hydrolyzed copolymer in the composition is 30 to 70% by weight, more preferably 40 to 60% by weight, from the viewpoint of water disintegration property and processability. As the unsaturated monomer containing no functional group, at least one selected from ethylene, propylene, isobutylene and styrene is used.

Next, examples of the thermoplastic fibers used in the present invention include fibers using the following general-purpose resins. Polyolefin resin such as low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, polyamide resin such as nylon 6 and nylon 66, polyester resin such as polyethylene terephthalate, polybutylene terephthalate and copolyester can be used. . Note that, in consideration of the fact that the absorbent article is disposed of after use, fibers using the following biodegradable thermoplastic resin can be exemplified. Synthesized by microorganisms,
As a biodegradable polyester produced, poly [(R) -3-
Hydroxybutyrate], polyhydroxybutyrate /
Valylate also has poly (γ-
Glutamic acid) and poly (ε-lysine) can be used. Also,
As the chemically synthesized polymer, polyglycolic acid, polylactic acid, poly (γ-methyl-L-glutamate), poly (ε-caprolactone), polybutylene succinate, polyethylene succinate and the like can be used. At least one of the above-mentioned thermoplastic resins can be used as a thermoplastic fiber. As the thermoplastic conjugate fiber, the above biodegradable thermoplastic resins can be used in combination so that the melting point of the resin is 10 ° C. or more lower on the sheath side than on the core side.

Next, in the present invention, the water-disintegrating action time of the water-disintegrating fiber can be controlled to some extent by adding the following thermoplastic biodegradable resin as a decomposition rate adjusting agent, if necessary. As the decomposition rate regulator used,
Poly [(R) -3-hydroxybutyrate], polyhydroxybutyrate / valylate, poly (γ-glutamic acid), poly (ε-lysine), polyglycolic acid, polylactic acid,
Examples thereof include poly (γ-methyl-L-glutamate), poly (ε-caprolactone), polybutylene succinate, and polyethylene succinate. The compounding amount of the decomposition rate adjusting agent is 1 to 50% by weight, more preferably 3 to 40% by weight in the composition, which is effective in terms of water disintegration. 5
If it exceeds 0% by weight, the water-disintegrating property almost disappears, and if it is less than 1% by weight, the performance is the same as that of the unadded product.

The above starch-based polymer compound, a partial hydrolysis copolymer, and a decomposition rate adjusting agent are blended, and in addition to these, a plasticizer, a matting agent, a pigment, a light stabilizer, a heat Various additives such as stabilizers and antioxidants can be added within a range that does not impair the effects of the present invention. For example, the spinnability can be improved by adding a plasticizer. Examples of the plasticizer include the following compounds of glycols or ethanolamine. Specifically, ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, propylene glycol, glycerin, 2,3-butanediol, 1,3-butanediol, diethylene glycol, triethylene glycol, 1 Examples thereof include 7,7-heptanediol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, pinacol, hydrobenzoin and benzpinacol.

In the present invention, the water-disintegratable fibers 100 to 3 are used.
A non-woven fiber aggregate of 0% by weight and 0 to 70% by weight of thermoplastic fibers can be preferably used as a surface material, an absorbent material such as a flush toilet, and an absorbent material that can be disposed of in sewage. As a method for mixing the water-disintegratable fiber and the thermoplastic fiber, known methods such as a card machine method and an airlaid method can be used. Although the mixed non-woven fiber aggregate can be used as it is, by heating the thermoplastic fibers present in the non-woven fiber aggregate, it is possible to perform heat fusion at the fiber intersections to form a non-woven fabric. You can Further, the starch-based polymer compound in the water-disintegratable fiber also has a certain degree of tackiness due to humidification, which contributes to the formation of a non-woven fabric.

The performance of the absorbent article of the present invention will be described below with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples. Absorbent article production method: Evaluation uses the area and weight value of the absorbent article used in a general disposable diaper.
Area of surface material, basis weight is 32 cm x 12 cm, 20 g /
m ² , the area of the absorbent, and the basis weight are 32 cm × 12 cm,
It was 400 g / m ² . As the surface material, fibers were passed through a card machine to prepare a web, and then heat-treated to obtain a non-woven fiber aggregate. The absorbent is mainly composed of a mixture of pulp fibers and a high-absorbent polymer absorber. When this absorbent article is flushed in a toilet or the like, the main purpose is to quickly dissociate the fibers from each other with water, further prevent clogging, and dispose of them. It was evaluated according to the street.

Water disintegration measuring method: The following simulated flush toilet is used. The pseudo toilet used for evaluation is 0.3mx vertical
In the center of the bottom of the water tank 0.3m wide x 0.5m high, 3c in diameter
It has a structure in which a hose with a hole for m and a cock for water stop is connected to the hole. This water tank is installed so that the height from the bottom of the water tank to the opening of the hose is 0.45 m. Further, the following data was collected to determine the water disintegration property. (1) Time required for the sample to disperse until it occupies an area of 0.3 m × 0.3 m (dispersion time). (2) After the sample was dispersed up to the condition of (1), the water in the simulated toilet was drained from the hose, the water in the aquarium was completely discharged, and the sample remaining after being clogged in the hose was collected and thoroughly dried. , Weigh. The residual ratio (%) is calculated from this value and the initial absolute dry weight. The remaining ratio can be obtained from the following equation. Remaining ratio (weight ratio of sample clogged in hose (%)) = [absolute dry weight of sample clogged in hose (g) / initial absolute dry weight of sample (g)] x 100

The measurement procedure is as follows. 1) Close the water stopcock to prevent water from flowing out of the hose. 2) Pour 9 dm ³ of water into this tank. 3) Soak 50 ml of pure water into the sample. 4) Put the evaluation sample into the water tank, and at the same time, proceed to (1) above.
Measure the time to the condition. 5) After dispersion up to the condition of (1) above, add 27 dm ³ of water to the water tank and fully open the water stopcock. 6) After the water is completely discharged, collect the sample remaining in the hose and weigh it. 7) The overall evaluation of water disintegration is judged from the dispersion time in (1) and the residual ratio in (2). Since the absorbent article of the present invention is mainly used for disposable diapers and sanitary napkins, after use, the absorbent article can be flushed into the toilet without being clogged even if it is thrown into the toilet as it is. Since it is considered to be the most important factor, the performance evaluation also checked that the fiber morphology collapses extremely quickly after being thrown into water, and that the constituent fibers can be separated and that the fibers discharged from the toilet do not become clogged. The dispersibility and the residual ratio measured in this manner are classified into four stages, and shown in Table 1 and Table 2, respectively. In addition, in these tables, the measured values were rounded to four decimal places.

[0027]

[Table 1] When the dispersion was not completed even after the dispersion time of 31 seconds, it was discharged out of the system after 31 seconds.

[0028]

[Table 2] A product having a residual ratio of 0 to 30% by weight shows good water disintegration as a product.

[0029]

【Example】

Example 1 (when the weight ratio of water-disintegratable fiber is 100) Preparation of water-disintegrable fiber: 60% by weight of starch containing 10% by weight of water, which was heat-denatured from Corn starch, and 30 mol of ethylene % Polyvinyl acetate 70 mol% was used as a copolymer, and a partially hydrolyzed copolymer having a saponification degree of 98% was used as a copolymer.
After mixing at a composition ratio of wt%, granulation was performed to obtain pellets.
This fiber was melt-spun at a spinning temperature of 140 ° C. using a full flight screw with a spinneret having a diameter of 350 mm and a compression ratio of 2.0 with a spinneret having a hole diameter of 350 mm. 6d / f regular
I got a thread. As a surface finishing agent, lauryl phosphate
0.3 wt% of potassium salt was deposited. This undrawn yarn was drawn at room temperature and then crimped to provide 12 crimps / 25 mm. This tow is cut with a cutter, and the single yarn fineness is 3
A water-disintegratable fiber having d / f and a fiber length of 38 mm was obtained. The water-disintegratable fiber was carded with a carding machine to obtain a card web, which was treated with hot steam to obtain a non-woven fiber aggregate, which was used as a surface material. Preparation of Absorbent Material: The absorbent material was prepared by uniformly mixing pulp fibers, starch-acrylic acid graft polymer (polymer absorbent) and water-disintegrating fibers with a tissue.

Preparation of back sheet: The above pellets were used and extruded from a T-die to give a film having a basis weight of 20 g / m ² . An absorbent article was manufactured using the surface material, the absorbent material, and the back sheet manufactured by the method described above. After 50 ml of water was absorbed in this absorbent article, it was dumped in a simulated toilet and the water disintegration performance was investigated. As a result, both the backsheet and the surface material were dissolved in water and disappeared, but the pulp and the polymer absorbent constituting the absorbent remained in the water as they were and gradually dispersed. The hose cock was opened and the remaining amount of the sample was checked, but nothing was left on the hose and all was discharged. That is, the water disintegration was good. Detailed results are shown in Table 3. However, in the comprehensive evaluation shown in Table 3, the dispersion time (dispersibility) and the residual ratio are comprehensively judged and classified and displayed in four stages.

[0031]

[Table 3] Comprehensive evaluation considers dispersion time and remaining ratio comprehensively and
~ 4 were ranked and 3 or more were made usable.

Example 2 (100% by weight of water-disintegrating fiber)
Preparation of water-disintegrating fiber: 60% by weight of starch containing 8% by weight of water, which was heat-denatured from Cornstarch as a raw material, copolymer of 30% by mole of ethylene and 70% by mole of polyvinyl acetate. 38% by weight of the partially hydrolyzed copolymer having a saponification degree of 98% and glycerin as a plasticizer at a composition ratio of 2% by weight were mixed and then granulated to obtain pellets. The following steps and evaluations were performed in the same manner as in Example 1. As a result, the spinnability was better than that without glycerin. Water disintegration was good. Detailed results are shown in Table 3.

Example 3 (when the weight ratio of the water-disintegrating fiber is 30) Preparation of water-disintegrating fiber: A water-disintegrating fiber was prepared in the same manner as in Example 1. Preparation of thermoplastic fiber: Melt flow rate 13 (g / 10mi
n: 190 ° C, 2.16kgf), melting point 114 ° C polybutylene succinate (manufactured by Showa High Polymer; brand name "Bionore # 10"
Fiberizing was performed under the following conditions using the resin of 10 "). Melt spinning was performed at a spinning temperature of 210 ° C. using a spinneret having a diameter of 350 mm and a die having a number of holes of 350 and a compression ratio of 4.2. 6d / f regular yarn was obtained. In addition, potassium lauryl phosphate was attached as a surface finishing agent in an amount of 0.3% by weight. This undrawn yarn is at 40 ° C for 2
It was stretched by a factor of 2 and crimped to provide crimps of 12 peaks / 25 mm. This tow is cut with a cutter, and the single yarn fineness is 3d /
f, a thermoplastic fiber having a fiber length of 38 mm was obtained. 30% by weight of water-disintegrating fiber and 70% by weight of thermoplastic fiber were carded with a carding machine to obtain a card web, which was treated with hot steam at 120 ° C. for 5 seconds to make a non-woven fiber aggregate, which was used as a surface material. did. The absorbent and the backsheet used were those produced in Example 1.
An absorbent article was produced using these. When evaluated in the same manner as in Example 1, the backsheet was dissolved in water and disappeared, and the surface material and the absorbent were gradually dispersed after being dropped in water. When the cock of the hose was opened and the remaining amount of the sample was checked, thermoplastic fibers and pulp that did not dissolve in water remained in the hose in the form of small beads, but the hose was not clogged. Detailed results are shown in Table 3.

Example 4 Preparation of water-disintegrating fiber: A water-disintegrating fiber was prepared in the same manner as in Example 1. Preparation of thermoplastic fiber: Melt flow rate 13 (g / 10mi
n: 190 ° C, 2.16kgf), melting point 114 ° C polybutylene succinate (manufactured by Showa High Polymer; brand name "Bionore # 10"
10 ") on the core side of the composite fiber and melt flow rate 14
(G / 10min: 190 ℃, 2.16kgf), melting point 94 ℃ polyethylene succinate (manufactured by Showa High Polymer; brand name "Bionore"
# 3010 ") was used on the sheath side to carry out fiberization under the following conditions. Melt spinning was carried out at a spinning temperature of 210 ° C. using a sheath-core type composite fiber spinner having a hole diameter of 350 mm and a full flight screw having a compression ratio of 2. A 6 d / f sheath-core type composite fiber was obtained. A water-repellent finishing agent was added as a surface finishing agent in an amount of 0.5% by weight to suppress fusion. This unstretched yarn is stretched at 40 ° C. and doubled, and 12 threads / 25 with a crimper.
mm crimp was applied. Cut this tow with a cutter,
A thermoplastic fiber having a single yarn fineness of 3 d / f and a fiber length of 38 mm was obtained. 30% by weight of water-disintegrating fiber and 70% by weight of thermoplastic fiber were carded with a carding machine to obtain a card web.
A non-woven fiber aggregate was made into a surface material by an air-through processing machine at 00 ° C for 5 seconds. Example 1 for the absorbent material and the back sheet
I used the one manufactured in. An absorbent article was produced using these. When evaluated in the same manner as in Example 1, the backsheet was dissolved in water and disappeared, and the surface material and the absorbent were gradually dispersed after being dropped in water. Open the hose cock,
When the residual amount of the sample was examined, thermoplastic fibers and pulp that did not dissolve in water became a beaded shape and remained partly in the hose, but the hose was not clogged. Detailed results are shown in Table 3.

Example 5 (when a decomposition rate adjusting agent was added to water-disintegrating fiber) Preparation of water-disintegrating fiber: 60 weight parts of starch containing 10 weight% of water content which was heat-denatured from cone starch %, Ethylene 30 mol% polyvinyl acetate 70 mol% as a copolymer with a degree of saponification of 98% and a partially hydrolyzed copolymer 37
The mixture was mixed with 1% by weight of polylactic acid at a composition ratio of 3% by weight and then granulated to obtain pellets. The fiberization of this product is 0.8 mm,
Melt spinning was performed at a spinning temperature of 140 ° C. using a spinneret having 350 holes and a full flight screw having a compression ratio of 2.0.
6d / f regular yarn was obtained. In addition, potassium lauryl phosphate was attached as a surface finishing agent in an amount of 0.3% by weight. The unstretched yarn was stretched at 40 ° C. and doubled, and then crimped to provide 12 crimps / 25 mm. This tow is cut with a cutter, and the single yarn fineness is 3 d / f and the fiber length is 38 mm.
A water-disintegratable fiber of When the following steps and evaluations were performed in the same manner as in Example 1, the surface material became soft with water,
The morphology as a fiber remained in the water while maintaining it. The backsheet disappeared after being dropped. The absorbent was gradually poured into water and then gradually dispersed. The cock of the hose was opened and the remaining amount of the sample was checked. The surface material was broken up by the water flow and completely discharged. Water disintegration was good. Detailed results are shown in Table 3.

Comparative Example 1 (20% by weight of water-disintegratable fiber)
%) Preparation of water-disintegratable fiber: A water-disintegrable fiber was prepared in the same manner as in Example 1. Preparation of thermoplastic fiber: A thermoplastic fiber was prepared in the same manner as in Example 3. 20% by weight of water-disintegrating fibers and 80% by weight of thermoplastic fibers were carded with a carding machine to prepare an absorbent article in the same manner as in Example 3, and evaluated. The backsheet was dissolved in water and disappeared. However, after dropping the surface material and the absorbent material into the water,
It was gradually dispersed. When the cock of the hose was opened and the remaining amount of the sample was checked, 45% by weight of the thermoplastic fiber and pulp which were not dissolved in water remained in the hose.
Detailed results are shown in Table 3. In Table 3, the dispersion time of 30 means that the particles were not sufficiently dispersed even after the dispersion time of 30 seconds. Therefore, the particles were discharged after 30 seconds and the residual ratio was measured.

Comparative Example 2 (10% by weight of water-disintegrating fiber)
%) Preparation of water-disintegratable fiber: A water-disintegrable fiber was prepared in the same manner as in Example 1. Preparation of thermoplastic fiber: A thermoplastic fiber was prepared in the same manner as in Example 3. When 10% by weight of the water-disintegrating fiber and 90% by weight of the thermoplastic fiber were carded with a carding machine, an absorbent article was prepared in the same manner as in Example 3 and evaluated. The backsheet was dissolved in water and disappeared. However, after dropping the surface material and the absorbent material into the water,
It was gradually dispersed. When the cock of the hose was opened and the remaining amount of the sample was checked, the hose was clogged with the thermoplastic fiber and pulp which were not dissolved in water. Detailed results are shown in Table 3.

It has been found that when the mixing ratio of the water-disintegratable fibers is less than 30% by weight, the thermoplastic fibers are less likely to be spread apart and the hose is likely to be clogged. From this, the ratio of water-disintegrating fiber to thermoplastic fiber is 10
It was found that good water disintegration performance was obtained in the range of 0/0 to 30/70. The ethylene used in each example is
It is a typical example of an unsaturated monomer containing no functional group, and other propylene, isobutylene and styrene can similarly obtain the effects of the present invention.

[0039]

The absorbent article using the water-disintegratable fiber of the present invention can disintegrate in a very short time when dropped in water at room temperature, and its form can be disintegrated. Therefore, since it can be easily disposed of by flushing it into the sewage (flush toilet), it can be used for a wide range of purposes as a sanitary material.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location A61F 13/18 307G

Claims (5)

[Claims] 1. A water-disintegrating composition obtained by melt spinning a water-disintegrating composition comprising a starch-based polymer compound and a copolymer obtained by partially hydrolyzing a copolymer of vinyl acetate and an unsaturated monomer containing no functional group. An absorbent article using a non-woven fiber aggregate composed of 100 to 30% by weight of functional fibers and 0 to 70% by weight of thermoplastic fibers. 2. The functional group-free unsaturated monomer is at least one selected from ethylene, propylene, isobutylene and styrene, and the partially hydrolyzed copolymer has a saponification degree of 78 to 98%, and The absorbent article according to claim 1, wherein the compounding amount of the partially hydrolyzed copolymer is 30 to 70% by weight. 3. The absorbent article according to claim 1, wherein the thermoplastic fiber is a heat-fusible composite fiber. 4. The absorbent article according to claim 1, wherein the non-woven fiber aggregate is used as a surface material. 5. The absorbent article according to claim 1, wherein the nonwoven fiber assembly is used as an absorbent material.