JP2001104370A - Absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent article capable of eliminating odor components resulting from body odor, in addition to odor components resulting from excrement. SOLUTION: The absorbent article comprises a liquid-permeable front sheet, a liquid-impermeable back sheet, and an absorbent positioned between both sheets. The absorbent contains modified activated carbon of 10 to 50 wt.% per unit weight of the absorbent, the modified activated carbon comprising acid-modified activated carbon whose surface is treated with an acidic substance, alkali-modified activated carbon whose surface is treated with an alkali, and amine-modified activated carbon having an amine compound added to its surface, with the acid-modified activated carbon, the alkali-modified activated carbon and the amine-modified activated carbon blended together in a ratio of 5-30:5-30:40-90.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an absorbent article, and more particularly to a disposable diaper for babies, a disposable diaper for adults, a pad for incontinent persons, a urine pad for light incontinent persons, a sanitary napkin, a pad for pets, etc. The present invention relates to an absorbent article used for:

[0002]

2. Description of the Related Art Absorbent articles such as disposable diapers include a liquid-permeable top sheet and a liquid-impermeable back sheet.
It has a structure in which a plurality of absorbers composed of a hydrophilic sheet, cotton-like pulp, and an absorbent material (for example, a high-absorbency polymer) are arranged. For urine, sweat, and other body fluids, a liquid-permeable surface sheet is used. Since it passes through and is absorbed and held by the absorber, it can be used for a long time, and its usage is increasing year by year due to its convenience. However, absorbent articles such as disposable diapers and sanitary pads have a problem in that each excrement absorbed by the absorber generates a unique unpleasant odor.

Hitherto, as a means for preventing such odors, a method using activated carbon zeolite has been proposed. However, the deodorizing function by such a method can only provide a deodorizing effect by physical adsorption, and has a sufficient effect. Not to say, it was not satisfactory. Further, various methods have been proposed to solve these problems. For example, Japanese Patent Publication No. 59-105448 discloses a deodorizing article in which thin paper containing activated carbon is sandwiched in a nonwoven fabric and arranged in an absorber, but like activated carbon zeolite, physical absorption capacity is obtained only with untreated activated carbon. However, the effect of deodorizing ammonia and the like cannot be said to be sufficient, and the problem has not been solved.

[0004] Similarly, Japanese Patent Publication No. 6-51045 discloses a deodorant in which a weakly acidic silver-containing glass powder containing phosphoric acid as a main component is dispersed in an absorber. Although it has the effect of adsorbing a basic gas such as trimethylamine, it does not contribute to the absorption of acidic gas substances such as hydrogen sulfide and methyl mercaptan, so that a sufficient deodorizing effect cannot be obtained. In addition, Tokuhei 8-
No. 126661 discloses a method for deodorizing by decomposing an odor component with an enzyme, but has a problem that the method for preparing the enzyme is complicated and expensive. In addition, many synthetic resin deodorants have been developed,
There was a problem that it was still expensive and was not suitable for use as a deodorant for disposable diapers and the like.

[0005]

As described above, conventional techniques for imparting deodorant properties to absorbent articles include urine odor,
A method of arranging untreated activated carbon in a disposable diaper to adsorb and remove menstrual odor, or a method of dispersing an antibacterial substance on the inner and outer surfaces of an absorbent material has been proposed. It only acts to adsorb and fix some neutral gases, and it has not been possible to efficiently deodorize mixed odors contained in excrement. Further, since the antibacterial substance is very expensive, the amount used is limited, and there remains a drawback that a sufficient effect cannot be obtained.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional absorbent articles, and not only to deodorize ammonia odor, but also to obtain methyl mercaptan or hydrogen sulfide which is acidic gas odor caused by fecal odor. An object of the present invention is to provide an inexpensive, deodorizing absorbent article that can remove various odors such as odors of aldehydes of manure and also body odor caused by perspiration while removing odors.

[0007]

According to the present invention, there is provided an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber disposed between these sheets. In the body, 10-5 per unit weight of the absorber
0% by weight of modified activated carbon particles, wherein the modified activated carbon is an acid-modified activated carbon whose surface is treated with an acidic substance;
The present invention relates to an absorbent article comprising a base-modified activated carbon whose surface has been treated with a basic substance and an amine-modified activated carbon whose surface has been treated with an amine compound. Further, in the present invention, the compounding ratio of the modified activated carbon is acid-modified activated carbon: base-modified activated carbon: amine-modified activated carbon = 5 to 30: 5 to 30:
It is related with an absorptive article characterized by being 40-90.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the surface of an absorbent article of the present invention is treated with an acidic substance (hereinafter referred to as acid treatment).
Absorbs activated carbon particles treated with a basic substance (hereinafter, referred to as base treatment), and modified activated carbon obtained by blending activated carbon with an amine compound (hereinafter, referred to as amine treatment) at a specific ratio. Contains a certain amount in the body. The absorbent article of the present invention having such a configuration is capable of efficiently removing malodor such as ammonia odor, mercaptan odor, and aldehyde odor caused by excrement.

The modified activated carbon used in the present invention comprises:
It consists of acid-modified activated carbon such as coconut shell activated carbon or synthetic activated carbon whose surface is acid-treated, base-modified base-modified activated carbon, and amine-treated amine-modified activated carbon. The compounding ratio is acid-modified activated carbon: base-modified activated carbon: amine-modified activated carbon. = 5 to 30: 5 to 30: 40 to 90, more preferably acid-modified activated carbon: base-modified activated carbon: amine-modified activated carbon = 10 to 25: 7 to 15: 30 to 70.

When the mixing ratio of the acid-modified activated carbon in the modified activated carbon is less than 5, it is insufficient to adsorb ammonia and trimethylamine-based odors. It may promote the generation of mercaptan-based acid gas. Further, if the blending ratio of the base modified activated carbon in the modified activated carbon is less than 5,
It is not enough to adsorb hydrogen sulfide and methyl mercaptan odor. On the other hand, if the compounding ratio exceeds 30, the hydroxyl ions added to the activated carbon by the basic treatment become excessive, and the material constituting the absorber, There is a possibility that the absorption performance of the absorbent resin is reduced. Furthermore, if the blending ratio of the amine-modified activated carbon in the modified activated carbon is less than 40, the effect of removing odors due to neutral gases is insufficient, while if the blending ratio exceeds 90, the cost of activated carbon production by amine treatment increases. It is expensive and disadvantageous for the economics of disposable diapers. Further, each of these modified activated carbons has a particle size of 4 to 8 mesh and a specific surface area of 1000 to 1000.
3000 m ² / g, and a packing density of 0.3 to 0.7 g / g
It is preferably ml.

Among the modified activated carbons used in the present invention, the acid-modified activated carbon having a surface acid-treated has a function of reacting with a basic gas such as ammonia or trimethylamine, neutralizing the same, and adsorbing and fixing the same. As the acidic substance used for the acid treatment, sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid and the like can be used.

Among the modified activated carbons used in the present invention, the base-modified activated carbon whose surface has been treated with a base reacts with an acidic gas such as hydrogen sulfide or methyl mercaptan to neutralize and adsorb and fix it. Have. As the basic substance used for the base treatment, sodium hydroxide, potassium hydroxide and the like can be used.

Further, among the modified activated carbons used in the present invention, the amine-modified activated carbon having an amine-treated surface reacts with a neutral gas having an irritating odor such as acetaldehyde, formaldehyde, etc., and is converted to an odorless gas by a Schiff reaction. Has the effect of converting the compound to Examples of the amine compound used for the amine treatment include aniline, 2- (2-aminoethylamino) ethanol, alkanolamine, methylamine, ethylamine, dimethylamine, diethylamine,
Trimethylamine, triethylamine and the like can be used.

The modified activated carbon used in the present invention comprises:
It is contained in the absorber in an amount of 10 to 50% by weight per unit weight of the absorber. When the content of the modified activated carbon is less than 10% by weight, it is insufficient to adsorb odor components generated from manure and malodor components such as body odor contained in sweat, while when the content exceeds 50% by weight, disposable diapers are used. If an excessive load is applied during the use of, the activated carbon may fall off the topsheet, giving the user a sense of discomfort. As a method of blending the activated carbon into the absorber, the activated carbon may be uniformly mixed with the absorber, or the activated carbon may be blended in the absorber in one or more layers. In the present invention, the modified activated carbon may be contained in the topsheet in the same manner as the absorber.

The modified activated carbon composition of the present invention exhibits excellent deodorizing ability against various malodors. As is evident from the test results described later, as typical malodorous components, a large amount of ammonia, nitrogen compounds such as amines, sulfur compounds such as hydrogen sulfide mercaptan, and further, are derived from lower fatty acids and the like. Various odor components can be efficiently removed.

Among the above-mentioned malodorous components, amines include:
For example, aliphatic primary amines such as methylamine, ethylamine, propylamine, isopropylamine, butylamine, and amylamine; aliphatic secondary amines such as dimethylamine, diethylamine and diisopropylamine; trimethylamine and aliphatic tertiary amines such as triethylamine; Examples thereof include aliphatic unsaturated amines such as arylamines, alicyclic amines such as cyclobutylamine, and aromatic amines such as aniline.

Among the malodorous components, examples of the mercaptans include methyl mercaptan, ethyl mercaptan, propyl mercaptan, isopropyl mercaptan, aryl mercaptan, benzyl mercaptan and the like. Further, among the malodorous components, examples of the fatty acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid, acrylic acid, crotonic acid, and isocrosonic acid.

The topsheet used in the present invention is:
Nonwoven fabrics, woven fabrics, porous plastic films, porous foams, reticulated foams and the like made of polyethylene, polypropylene, and other thermoplastic fibers are used. Further, natural fibers (for example, wood fibers, cotton fibers, etc.) may be used, and furthermore, it can be manufactured from a wide range of materials such as a combination of synthetic fibers and natural fibers. Since it is a contacting portion, any material that is soft and has a good touch may be used. When the material of the surface sheet is water repellent, a surface sheet subjected to a hydrophilic treatment is used.

In the present invention, a liquid-impermeable sheet made of polyethylene or the like is used as the back sheet. In particular, a plastic sheet that has many micropores that do not allow the passage of liquid but allows water vapor to pass, a vapor-permeable sheet obtained by adding a filler to a thermoplastic resin, or a nonwoven fabric outside these sheets It is preferable to use a composite sheet or the like in which the moisture inside the diaper is released to the outside and stuffiness and rash are prevented.

The absorbent used in the present invention is preferably one comprising cotton-like pulp as a main material and a superabsorbent polymer in combination, and other than that, absorbent paper alone, or a mixture or laminate of heat-fused fibers or the like is used. Can be Further, a laminated structure in which the whole is wrapped with tissue may be used. The shape of the absorber may be an hourglass type, a rectangular shape or the like, but the hourglass type provides better fit.

As the cotton-like pulp, those having a fiber length of 5 mm or less obtained by defibrating sheets of chemical pulp, mechanical pulp, waste paper pulp and the like with a defibrating machine are used. Pulp raw materials include straw, bamboo,
Kenaf, bagasse and the like can also be used. The amount of pulp used varies depending on the intended absorber, for example, a single absorbent, a plurality of laminated absorbents, or a combination of other absorbents, but generally 50 to 400 g / m ² . is there.
In addition, synthetic fibers, heat-sealing substances, adhesives and the like may be used together with the cotton-like pulp.

The superabsorbent polymers include starch-based polymers,
Cellulose type and synthetic polymer type are mentioned. That is, saponified starch-acrylic acid (salt) graft copolymer, starch-ethyl acrylate graft copolymer, saponified starch-methyl methacrylate graft copolymer, saponified starch-acrylonitrile graft copolymer , Starch-acrylamide graft copolymer, saponified starch-acrylonitrile 2-acrylamido-2-methylpropanesulfonic acid graft copolymer, acrylic acid (salt) polymer, polyethylene oxide cross-linked with acrylic acid And a crosslinked product of sodium carboxymethyl cellulose and a crosslinked product of a polyvinyl alcohol-maleic anhydride reactant. Some of these have the ability to absorb urine, body fluid, and water that are 20 times or more their own weight, but it is preferable to use a synthetic resin-based sodium polyacrylate that has an absorption capacity that is 50 times or more their own weight. These absorbent materials may be used alone or in combination of two or more. Further, the absorbent material may be in the form of particles or fibers, and the size is not particularly limited.

[0023]

EXAMPLES Hereinafter, the effects of the absorbent article of the present invention will be described in detail with reference to examples, but the present invention is not limited by the following examples. Example 1 Acid-modified activated carbon (Kuraray Chemical Co., Ltd., product name: 4T-B, particle size 4 to 6 mesh, packing density 0.5 to 0.6 g / ml) obtained by treating the surface of coconut shell activated carbon particles with acid with sulfuric acid was used. 5 parts by weight, base modified activated carbon (Kuraray Chemical Co., product name: 4G-H, particle size 4-6 mesh, packing density 0.4)
-0.45 g / ml) in 5 parts by weight, and JP-A-63-2
Amine-modified activated carbon obtained by treating the surface of coconut shell activated carbon particles with amine from aniline (particle size: 5 to 8 mesh, packing density: 0.55 to 0.55) in accordance with the method described in JP-A-83645.
(0.65 g / ml) was mixed with 90 parts by weight to prepare a mixture of modified activated carbon. Then, 150g of fluff pulp /
m ² and a highly absorbent polymer 150 g / m ² were uniformly mixed, and the mixture of the modified activated carbon was uniformly dispersed in an amount of 20% by weight (based on the absorber) on an absorber having a length of 40 cm and a width of 15 cm formed by mixing. After the addition, this was covered with a topsheet made of a spunbond nonwoven fabric having a basis weight of 25 g / m ² , and the other surface of the absorber was covered with a backsheet made of polyethylene film having a thickness of 24 μm. The periphery was joined to produce an absorbent article, which was used as a test sample.

Example 2 Each of the modified carbons used in Example 1 was the same as that used in Example 1. The ratio of the acid-modified activated carbon was 10 parts by weight, the base-modified activated carbon was 10 parts by weight, and the amine-modified activated carbon was 80 parts by weight. An absorbent article was produced in the same manner as in Example 1 except that the mixture was used as a test sample.

Example 3 Each of the modified activated carbons used was the same as that used in Example 1, and 20 parts by weight of the acid-modified activated carbon, 20 parts by weight of the base-modified activated carbon, and 60 parts by weight of the amine-modified activated carbon were used. An absorbent article was prepared and used as a test sample in the same manner as in Example 1 except that the mixture was used at a ratio.

Example 4 As the modified activated carbon, the same one as used in Example 1 was used. 30 parts by weight of acid-modified activated carbon, 30 parts by weight of base-modified activated carbon, and 40 parts by weight of amine-modified activated carbon were used. An absorbent article was prepared and used as a test sample in the same manner as in Example 1 except that the mixture was used at a ratio.

Example 5 As each modified activated carbon, the same one as used in Example 1 was used. The proportion of acid-modified activated carbon was 10 parts by weight, base-modified activated carbon was 20 parts by weight, and amine-modified activated carbon was 70 parts by weight. An absorbent article was produced in the same manner as in Example 1 except that the mixture was used as a test sample.

Example 6 The same modified carbons as those used in Example 1 were used as the modified carbons in Example 1. 20 parts by weight of acid-modified activated carbon, 10 parts by weight of base-modified activated carbon, and 70 parts by weight of amine-modified activated carbon were used. An absorbent article was prepared and used as a test sample in the same manner as in Example 1 except that the mixture was used at a ratio.

Comparative Example 1 Instead of the modified activated carbon, untreated coconut shell activated carbon particles (particle size: 7.5 to 30 mesh, packing density: 0.45 to 0.55)
g / ml and a specific surface area of 1000 to 2000 m ² / g), except that an absorbent article was produced in the same manner as in Example 1.
The test sample was used.

Comparative Example 2 Of the modified activated carbon shown in Example 1, 6
An absorbent article was prepared and used as a test sample in the same manner as in Example 1, except that a mixture of 5 parts by weight and 35 parts by weight of amine-modified activated carbon was used.

Comparative Example 3 Of the modified activated carbon shown in Example 1, acid-modified activated carbon
An absorbent article was prepared in the same manner as in Example 1 except that a mixture of 35 parts by weight of an amine-modified activated carbon was used as a test sample.

Comparative Example 4 Of the modified activated carbon shown in Example 1, 50 acid-modified activated carbons were used.
An absorbent article was prepared in the same manner as in Example 1, except that a mixture of 50 parts by weight of base-modified activated carbon was used as a test sample.

Using the absorbent articles obtained in Examples 1 to 6 and Comparative Examples 1 to 4, the deodorizing effect was tested by the following method.
It was determined as the removal rate. Test Method 1 (Ammonia) After placing the sample in a 1-liter capacity air-collecting bag and then enclosing ammonia gas at a concentration of about 100 ppm, after 60 minutes, insert a detector tube into the air-collecting bag to determine the residual concentration of ammonia gas. It measured and the removal rate was calculated | required.

Test Method 2 (Hydrogen Sulfide and Methyl Mercaptan) A sample was placed in an air-collecting bag having a capacity of 1 liter, and hydrogen sulfide was sealed at a concentration of about 100 ppm. After insertion, the residual concentration of hydrogen sulfide was measured, and the removal rate was determined. The same test was conducted for methyl mercaptan.

Test Method 3 (Trimethylamine) A sample was placed in a 1-liter air-collecting bag, the inside of the bag was evacuated, trimethylamine was injected (100 ppm), and the inside of the bag was returned to atmospheric pressure. A detector tube was inserted into the sachet, the residual concentration of trimethylamine was measured, and the removal rate was determined.

Test Method 4 (Valeric Acid) The sample was placed in a 1-liter air-collecting bag, the inside of the bag was evacuated, valeric acid was injected (100 ppm), and the inside of the bag was returned to atmospheric pressure. Thereafter, a detector tube was inserted into the air-collecting bag, the residual concentration of valeric acid was measured, and the removal rate was obtained.

The results of the deodorizing effect test of each sample are as shown in Table 1. As is clear from Table 1, the absorbent articles of the present invention of Examples are excellent in not only four major malodors such as ammonia, trimethylamine, hydrogen sulfide and methyl mercaptan caused by urine and feces, but also malodor such as valeric acid. It shows the removal rate, confirming the effect of the present invention.

[0038]

[Table 1]

[0039]

The absorbent article of the present invention contains a modified activated carbon in which an acid-modified activated carbon, a base-modified activated carbon, and an amine-modified activated carbon are blended in a specific ratio in an absorbent, and the odor caused by excrement is contained. It is possible to remove not only the ingredients, but also offensive odor components caused by body odor etc., and a wide range of disposable diapers for babies, adult disposable diapers, incontinence pads, light incontinence urine pads, sanitary napkins, etc. It can be used for any purpose.

Continued on the front page F term (reference) 3B029 BA04 BA12 BA18 BC03 BC06 BD22 4C003 AA08 AA19 AA23 AA26 CA06 HA01 4C098 AA08 DD02 DD03 DD16 DD19 DD23

Claims (2)

[Claims] 1. An absorbent article having a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber disposed between the two sheets, wherein the absorber comprises an absorber unit The modified activated carbon contains 10 to 50% by weight of modified activated carbon particles per weight, and the modified activated carbon includes an acid-modified activated carbon having a surface treated with an acidic substance, a base-modified activated carbon having a surface treated with a basic substance, and an amine having a surface treated with an amine. An absorbent article comprising an amine-modified activated carbon treated with a system compound. 2. The modified activated carbon has a compounding ratio of acid-modified activated carbon: base-modified activated carbon: amine-modified activated carbon = 5.
The absorbent article according to claim 1, wherein the ratio is 30: 5 to 30:40 to 90.