JP3141078B2 - Water disintegrable nonwoven fabric and laminate thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-disintegrable nonwoven fabric and a laminate thereof, and more particularly, to contact of a sanitary product such as a sanitary product, a disposable diaper with a limited amount of water or an aqueous solution during use. The present invention relates to a water-disintegrable nonwoven fabric and a laminate thereof, which do not break down the material due to dissolution and do not penetrate into the back surface, and disintegrate and can be discharged in water having an absorption capacity or more. Further, as a waste disposal method after used, in addition to the above-mentioned sewage discharge treatment, a microbial decomposition method by burial in the ground, or a low burn calorie of 4000 to 5000 kcal which is almost the same as natural fiber, An incineration method using an existing incinerator is possible.

[0002]

2. Description of the Related Art Conventionally, in contact with a limited amount of water at the time of use, the product has a function as a product without causing structural destruction of the product due to dissolution of the material. There was no polymer system that could be disintegrated and released, and also biodegraded by more microbial components. Therefore, common structures that are the basis of sanitary products such as sanitary products and disposable diapers include (1) a polyethylene net for protecting the surface and maintaining a dry state on the skin contact surface, and (2) absorbing water or blood. (3) a polyethylene film for preventing the permeation of clothes, and especially the polyethylene net and the film do not disintegrate. In the state of being contaminated and transported and treated with garbage discharged from ordinary households, especially when transported, the scattering of excrement due to the bursting of packaging bags is a hygiene problem for workers and is a social concern. Began to draw.

[0003]

As described above, conventionally available sanitary products such as sanitary products and disposable diapers have an existing structure in order to satisfy the functions required according to their usage. This is because no polymer system has been found that satisfies the conditions described above. Therefore, the present invention satisfies the above-mentioned functions as sanitary products such as sanitary products and disposable diapers, and at the same time, solves the problem of disposal treatment. An object of the present invention is to provide a water-disintegrable nonwoven fabric and a laminate thereof that can be treated in a place.

[0004]

According to the present invention, a polyester or polyolefin fiber nonwoven fabric treated with hydroxypropylcellulose or cellulose acetate propionate, a pulp fiber sheet containing the nonwoven fabric and a superabsorbent polymer, polyvinyl alcohol・
A laminate with a film and said nonwoven or water-disintegrable paper is provided.

According to a first aspect of the present invention, a water-disintegratable polyester or polyolefin fiber non-woven fabric is obtained by impregnating a polyester or polyolefin fiber web with a dilute solution of hydroxypropyl cellulose or cellulose acetate pyropionate and drying. Obtainable.

That is, according to a first embodiment of the present invention, a 2 to 5% by weight aqueous or methanol solution of hydroxypropylcellulose having a hydroxypropoxyl group content of 50 to 80%, or a propionyl group content of 40%, acetyl A polyester or polyolefin fiber sheet is impregnated with a 2-5% by weight n-propyl acetate solution of cellulose acetate propionate having a group content of 2.5% by a spray method or a gravure printing method, and dried to obtain a small amount of water. Alternatively, a water-disintegratable nonwoven fabric having wet strength sufficient for practical use in contact with an aqueous solution and disintegrating into a slurry in which fibers are dispersed in water having an absorption capacity or more can be obtained. The nonwoven fabric obtained in the present invention easily permeates water and an aqueous solution, and because of the water repellency of polyester or polyolefin fibers,
The dry state is obtained even on contact with water and aqueous solutions, providing a very interesting application. In other words, when using existing disposable diapers, stool is wrapped in the disposable diaper itself,
Transporting and disposing of it with general household waste
Although an extremely unsanitary disposal treatment method has been adopted, when the water-disintegrable nonwoven fabric obtained according to the first aspect of the present invention is used as a stool liner inside an existing disposable diaper, urination is easy. The stool remains on the thin water-disintegrating nonwoven fabric of the present invention used as a liner, so if it is wrapped and put into the water of a toilet, the whole becomes a slurry and can be discharged. Becomes Further, the used disposable diaper can be repeatedly used by inserting the water-disintegrable nonwoven fabric of the first aspect of the present invention until it becomes soiled. If the disposable diaper becomes unusable, it can be disposed of together with general household waste, thereby solving the problem of hygiene.

[0007] Hydroxypropylcellulose or cellulose acetate propionate used in the present invention is a very safe cellulose derivative. The following tests were conducted on hydroxypropylcellulose.
Acute oral toxicity was tested on mice and rats. As a result, even if 5 g / kg (the maximum amount that can be technically administered) was administered, no toxicity was exhibited and no death was observed. Further, as a result of the hemolysis test, there is no hemolysis effect.

[0008] US F. D. A. In, Federa
l Register (September 4, 1964) S
The use as a food additive is permitted in section 121 and 1160, and it is physiologically safe. In addition, the following test was performed on cellulose acetate propionate. As a result of an acute oral toxicity test on mice and rats, no toxicity was observed even when 5 g / kg was administered, and no death was observed. It has no carcinogenicity and is physiologically safe.

According to a second aspect of the present invention, there is provided a water-disintegratable nonwoven fabric of a polyester or polyolefin fiber containing hydroxypropyl cellulose or cellulose acetate propionate obtained in the first aspect of the present invention.
Stack pulp fiber sheets containing superabsorbent polymer,
Further, by superimposing the thermoplastic water-soluble polyvinyl alcohol film and the polyester or polyolefin fiber water-disintegrable nonwoven fabric or water-disintegrable paper and heating and bonding the periphery, the existing sanitary zone and disposable diaper function are provided.
Moreover, a water-disintegratable nonwoven fabric laminate that can be discharged into water in a toilet and collapsed into a slurry state after use to be released can be obtained.

That is, according to the second aspect of the present invention, by preparing the following material having a laminated structure, it has the function of an existing material at the time of use and collapses in water after use. Thus, a water-disintegrable laminate can be obtained which is changed into a slurry-like mixture of fibers and can be discharged into water. Next, the laminated structure is shown. (1) Polyester fibers containing 0.1 to 10% by weight, preferably 0.2 to 5% by weight of hydroxypropylcellulose or cellulose acetate propionate according to the first aspect of the present invention, or polyolefin fibers such as polyethylene and polypropylene. The water-disintegrable nonwoven fabric as the first layer is a layer directly in contact with the body.

(2) A pulp fiber sheet containing 1 to 10% by weight, preferably 1 to 5% by weight of a superabsorbent polymer is used as an intermediate absorbent layer. A pulp fiber sheet obtained from softwood or hardwood, which is usually used, is added with a superabsorbent polymer according to the required function. Examples of the superabsorbent polymer that can be used in the present invention include starch, cellulose, polyacrylic acid, polyvinyl alcohol, and polyoxyethylene.
Examples of the polymer include a polymer obtained by performing a reticulation reaction by a crosslinking agent, self-crosslinking, irradiation of radiation, or the like. The superabsorbent polymer actually used in the present invention is a highly safe polymer mainly composed of polyacrylic acid among the above superabsorbent polymers, and is an acute oral toxicity test using mice and rats. 1 month subacute toxicity test using, contact allergy test using guinea pig,
It shows completely safe data in mutagenicity tests, primary skin irritation tests, 30-day cumulative skin irritation tests, and the like. In addition, as a characteristic of this kind of compound, it is extremely easily decomposed by light irradiation.

(3) A thermoplastic water-soluble polyvinyl alcohol film having a thickness of 20 to 100 microns is used as a film for preventing leakage of absorbed liquid and an adhesive for a laminated structure. The polyvinyl alcohol used in the present invention is decomposed and assimilated by Pseudomonas bacteria (for example, T. Suzuki et al., Ag).
r. Biol. Chem. , 37 , 747 (197
3), C.I. Sakazawa et. al. , Appl.
Environ. Microbiol. , 41 , 261
(1981); Shimao et. al. , Ap
pl. Environ. Microbiol. , 49 ,
8 (1985)). Moreover, even if it comes into contact with the skin and mucous membranes of the human body or is taken orally into the digestive tract, it is practically completely harmless without being absorbed into human tissues. The thermoplastic water-soluble polyvinyl alcohol film includes, for example, an average degree of polymerization of 500 to 1000 and a degree of saponification of 85 to 88.
% Of polyvinyl alcohol, glycerin or polyethylene glycol (average molecular weight of about 400), and a composition using magnesium silicate at 180 to 220 ° C. under heating and kneading. (4) Laminating the water-disintegrable nonwoven fabric or water-disintegrable paper (paper containing 5 to 15% by weight of a water-soluble resin such as polyvinyl alcohol or carboxymethyl cellulose) used for the first layer on the polyvinyl alcohol film, The whole is heat-bonded to obtain the water-disintegrable nonwoven fabric laminate according to the second aspect of the present invention.

The water-disintegrable laminate obtained according to the second aspect of the present invention is, as described above, a surface of a water-disintegrable nonwoven fabric made of polyester or polyolefin fibers using hydroxypropylcellulose or cellulose acetate propionate as a binder. Is used so as to come into contact with the body of the user. At this time, the water or aqueous solution penetrates into the gaps between the polyester or polyolefin fibers, which are essentially hydrophobic fibers, and migrates to the pulp fiber sheet containing the superabsorbent polymer, which is then absorbed by the superabsorbent polymer. Is done. The water or the aqueous solution absorbed by the absorbing layer is prevented from penetrating to the outside by the polyvinyl alcohol film of the third layer, and remains inside the absorbing layer. When the thus used laminate is put into water having a water absorbing capacity or more, the laminate is disintegrated in water, becomes a slurry-like dispersion of fibers, and can be discharged. Non-woven fabrics of polyester or polyolefin fibers are very small in quantity and most components are biodegradable,
No significant impact on the environment. The water-disintegrating nonwoven fabric that comes into contact with the body may be partially fixed to the diaper main body with an adhesive tape so that it can be easily removed.

[0014]

Next, the present invention will be described in detail with reference to Examples.
It goes without saying that the invention is not limited to these examples.

Example 1 A nonwoven fabric of a polyester fiber web having a basis weight of about 50 g / m ² , obtained by printing a 2.5% by weight aqueous solution of hydroxypropylcellulose having a hydroxypropoxyl group content of 50% by a gravure printing method, was coated on an inner surface of an existing paper diaper. A practical test was carried out by inserting the device into a part in contact with the body. In the case of only urine, the urine was absorbed by the absorbent layer of the disposable diaper and could be used as before. In the case of stool, it was wrapped with the nonwoven fabric and put into a toilet, and it collapsed into a slurry state and could be discharged, and the used diaper could be prevented from being stained to the extent that it could be used again. Of course, once-used disposable diapers do not release moisture even under pressure, so they can be transported together with general household waste. Instead of an aqueous solution of hydroxypropylcellulose, a methanol solution of the same concentration can be used as well.
When impregnated with the solution having the above concentration, about 4% by weight of hydroxypropylcellulose could be adsorbed to the polyester fiber sheet.

Example 2 In Example 1, a sheet made of polyethylene fibers was used instead of the polyester fibers. The amount of hydroxypropylcellulose adsorbed was 2.5% by weight based on the polyethylene fiber sheet, which was smaller than that of the polyester fiber, but the same effect as in Example 1 was obtained.

Example 3 Propionyl group content 40%, acetyl group content 2.5
% Cellulose acetate propionate in a 2.5% by weight n-propyl acetate solution is printed by a gravure printing method. A nonwoven fabric consisting of a polyester fiber sheet and a polyethylene fiber sheet having a basis weight of about 50 g / m ² is 3 g / m 2. ² and 2.6 g / m ² of cellulose acetate propionate. A practical test was conducted by inserting these nonwoven fabrics into the portion of the inner surface of an existing disposable diaper that comes into contact with the body, as in Example 1. In the case of only urine, the urine was absorbed by the absorbent layer of the disposable diaper and could be used as before. In the case of stool, when it was wrapped with the nonwoven fabric and put into a toilet, it could be disintegrated into a slurry and released, and the used diaper could be prevented from being stained again to the extent that it could be used again. Of course, once-used disposable diapers do not release moisture even under pressure, so they can be transported together with general household waste.

Example 4 Non-woven polyester fiber containing about 5% by weight of hydroxypropyl acetate, absorbent layer of pulp fiber sheet, thermoplastic water-soluble polyvinyl alcohol film (thickness of 35)
Micron), the same polyester fiber non-woven fabric as above is superimposed, heated, bonded and cut as shown in FIG. By these operations, a sanitary band and a disposable diaper were prepared. The sanitary band and the disposable diaper having such a laminated structure have the same function as existing products, and when they are put into a toilet, they collapse into a slurry of fibers and can be discharged. In FIG. 1, the surface of (1) is used so as to be in contact with the body, but liquids such as blood and urine are absorbed by the absorbing layer of (2).
Moreover, the polyvinyl alcohol film of (2) shows leakproofness, and no penetration into the outside is observed.

[Brief description of the drawings]

FIG. 1 shows a schematic sectional view of a water-disintegrable nonwoven fabric laminate of the present invention.

[Explanation of symbols]

1) polyester or polyolefin fiber nonwoven fabric containing hydroxypropyl acetate or cellulose acetate propionate; 2) pulp fiber sheet absorbent layer containing superabsorbent polymer; 3) thermoplastic water-soluble polyvinyl alcohol film; And the same non-woven fabric or water-disintegrable paper, respectively.

────────────────────────────────────────────────── ─── Continuing from the front page Examiner Hiroaki Hirai (56) References JP-A-50-52371 (JP, A) JP-A-50-112562 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) B32B 1/00-35/00 D04H 1/00-18/00

Claims (3)

(57) [Claims] 1. Hydroxypropyl cellulose or cellulose soluble in an organic solvent and soluble or dispersible in water.
A water-disintegrable nonwoven fabric comprising a polyester or polyolefin fiber sheet containing 0.1 to 10% by weight of acetate propionate . 2. A water-disintegratable nonwoven fabric, a pulp fiber sheet, a thermoplastic water-soluble polyvinyl alcohol film according to claim 1 and a structure in which the water-disintegrable nonwoven fabric or water-disintegrable paper according to claim 1 is laminated. Characteristic water-disintegrable nonwoven laminate. 3. The water-disintegrable nonwoven laminate according to claim 2, wherein a pulp fiber sheet containing 1 to 10% by weight of a superabsorbent polymer is used.