阅读说明：本技术 纤维片及使用该纤维片的吸收性物品 (Fiber sheet and absorbent article using the same ) 是由 户田温树 村井隆将 宇都宫英人 于 2020-03-12 设计创作，主要内容包括：本发明提供一种兼具活性炭的优异的除臭性能和清洁感的纤维片。本发明是一种纤维片,其含有活性炭,其特征在于,所述活性炭具有粒径10μm以下的粒子的比例小于15％且粒径45μm以上的粒子的比例小于57％的粒度分布,相对于所述纤维片的单位面积质量而言的所述活性炭的含有率为2.0质量％以上且8.0质量％以下。(The invention provides a fiber sheet having excellent deodorizing performance and clean feeling of activated carbon. The present invention is a fibrous sheet containing an activated carbon, characterized in that the activated carbon has a particle size distribution in which the proportion of particles having a particle diameter of 10 μm or less is less than 15% and the proportion of particles having a particle diameter of 45 μm or more is less than 57%, and the content of the activated carbon per unit area mass of the fibrous sheet is 2.0 mass% or more and 8.0 mass% or less.)

1. A fibrous sheet comprising activated carbon, characterized in that,

the activated carbon has a particle size distribution in which the proportion of particles having a particle diameter of 10 [ mu ] m or less is less than 15% and the proportion of particles having a particle diameter of 45 [ mu ] m or more is less than 57%,

the content of the activated carbon is 2.0 mass% or more and 8.0 mass% or less per unit mass of the fibrous sheet.

2. The fiber sheet according to claim 1,

the particle size distribution of the activated carbon is such that the proportion of particles having a particle diameter of 20 μm or less is less than 53%.

3. The fiber sheet according to claim 1 or 2,

the activated carbon has a pore volume of 0.5-1.5 mL/g and an average pore diameter of 1.5-4.0 nm.

4. The fiber sheet according to any one of claims 1 to 3,

the raw material of the active carbon is coconut shell carbon or bamboo charcoal.

5. The fiber sheet according to any one of claims 1 to 4,

the fibrous sheet is a constituent member of a toilet paper, a wiping sheet for a toilet seat, or an absorbent article.

6. An absorbent article in which, in the case of a disposable absorbent article,

the absorbent article uses the fiber sheet according to any one of claims 1 to 4.

7. The absorbent article according to claim 6,

the fibrous sheet is a sheet-like member disposed at a position adjacent to an absorbent body of the absorbent article or inside the absorbent body, or a core sheet covering an absorbent core of the absorbent body.

Technical Field

The present invention relates to a fibrous sheet containing activated carbon and an absorbent article using the same.

Background

As a deodorizing sheet used for sanitary materials and the like, a fiber sheet carrying a deodorant such as activated carbon has been known.

As such a fiber sheet, for example, patent document 1 discloses a tissue paper comprising a single-layer sheet containing pulp fibers, activated carbon, and metal-loaded porous particles, wherein the pulp fibers have a freeness of 450mL or more and 680mL or less, the activated carbon has an average particle diameter of 1 μm or more and 15 μm or less, the cumulative amount of particles having a particle diameter of 40 μm or more in a particle diameter distribution of the activated carbon is less than 5% on a volume basis, the content of the activated carbon is 0.1 mass% or more and 1.5 mass% or less per unit area mass of the single-layer sheet, the average particle diameter of the metal-loaded porous particles is larger than the average particle diameter of the activated carbon, and the brightness L value of the single-layer sheet is 55 or more and 80 or less.

The tissue paper contains activated carbon, is not easy to fall off, has a color which properly reflects the black color of the activated carbon, and has excellent deodorization performance for excrement such as urine.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2014-70288

Disclosure of Invention

Problems to be solved by the invention

However, since the tissue paper (fibrous sheet) disclosed in patent document 1 has a color that appropriately reflects the black color of activated carbon, when applied to a sanitary material or the like that gives an impression of a generally white color, the black color of activated carbon may be recognized as dirt, and the clean feeling of appearance may be impaired.

In addition, as a means for making such black color of activated carbon less noticeable, it is conceivable to reduce the content of activated carbon, but if the content of activated carbon is reduced in this way, the deodorizing performance of activated carbon is lowered, and there is a possibility that it is difficult to exert the original function as a deodorizing sheet.

Accordingly, an object of the present invention is to provide a fibrous sheet having both excellent deodorizing performance and clean feeling of activated carbon.

Means for solving the problems

The present inventors have earnestly studied means for making the black color of activated carbon contained in a fibrous sheet less noticeable, and as a result, have found that the black color of activated carbon is less noticeable even if the content of activated carbon is a certain amount (an amount capable of exhibiting excellent deodorizing performance) or more by using activated carbon having a particle size distribution within a specific range, and have completed the present invention.

The invention comprises the following technical schemes.

One aspect (aspect 1) of the present invention is a fibrous sheet containing activated carbon, characterized in that,

the activated carbon has a particle size distribution in which the proportion of particles having a particle diameter of 10 [ mu ] m or less is less than 15% and the proportion of particles having a particle diameter of 45 [ mu ] m or more is less than 57%,

the content of the activated carbon is 2.0 mass% or more and 8.0 mass% or less per unit mass of the fibrous sheet.

In the present specification, the proportion of each particle in the particle size distribution is based on a volume basis.

The fiber sheet according to the present invention contains the activated carbon having the specific particle size distribution at the specific content, and therefore, the activated carbon can be prevented from falling off from the fiber sheet and the black color of the activated carbon is less noticeable, and therefore, the fiber sheet can have both excellent deodorizing performance and a clean feeling of the activated carbon.

In addition, according to the fiber sheet of claim 1, another aspect (claim 2) of the present invention is characterized in that the particle size distribution of the activated carbon is such that the proportion of particles having a particle diameter of 20 μm or less is less than 53%.

The proportion of the small-particle-size active carbon in the fiber sheet is small, so that the black color of the active carbon is less prone to being obvious.

According to the fiber sheet of claim 1 or 2, still another aspect (claim 3) of the present invention is characterized in that the activated carbon has a pore volume of 0.5mL/g or more and 1.5mL/g or less and an average pore diameter of 1.5nm or more and 4.0nm or less.

In the fibrous sheet according to the present invention, the activated carbon is particles having a large total adsorption amount (i.e., high deodorizing ability) of the specific pore volume and average pore diameter, and therefore, even if the content of the activated carbon in the fibrous sheet is reduced, a predetermined deodorizing ability can be sufficiently exhibited. Thus, the fiber sheet according to the present invention can ensure a predetermined deodorizing performance and make the black color of the activated carbon less noticeable by reducing the content of the activated carbon as much as possible.

According to any one of the above-described aspects 1 to 3, a further aspect (aspect 4) of the present invention is characterized in that the raw material of the activated carbon is coconut shell carbon or bamboo charcoal.

According to the technical scheme, the raw material of the activated carbon is a carbonized substance with higher hardness, such as coconut shell carbon or bamboo charcoal, so that the activated carbon exposed on the surface of the fiber sheet has higher hardness, and the activated carbon is more difficult to fall off.

According to any one of the above aspects 1 to 4, the present invention provides a further aspect (aspect 5) wherein the fibrous sheet is a component of a toilet paper, a wiping sheet for a toilet seat, or an absorbent article.

The fiber sheet according to the present invention is used as a component of toilet paper, a wiping sheet for a toilet seat, or an absorbent article, which particularly requires deodorizing properties and a clean feeling, and therefore the above-described effects of the fiber sheet can be exhibited to a very high degree. Further, the above-mentioned fibrous sheet has an advantage that the black color of the activated carbon is less noticeable, and therefore, it is easy to confirm the dirt (for example, excrement such as urine and feces) after the use of the toilet paper, the wiping sheet for a toilet seat, or the absorbent article.

Still another aspect of the present invention (aspect 6) is an absorbent article using the fibrous sheet according to any one of aspects 1 to 4.

Since the absorbent article according to the present invention uses the above-described fibrous sheet, it can achieve both excellent deodorizing performance and a clean feeling as an absorbent article.

According to the absorbent article of claim 6, a further aspect (claim 7) of the present invention is characterized in that the fibrous sheet is a sheet-like member disposed at a position adjacent to or inside an absorbent body of the absorbent article or a core sheet covering an absorbent core of the absorbent body.

Since the above-described fibrous sheet is disposed in the vicinity of the absorbent core that absorbs and retains excretory fluid such as urine, which causes generation of odor, the absorbent article according to the present embodiment can more effectively exhibit deodorizing performance. In addition, since the black color of the activated carbon in the above-described fibrous sheet is less noticeable, the absorbent article according to the present invention has an advantage that it is easy to confirm whether or not urination or the like is present.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a fiber sheet having both excellent deodorizing performance and clean feeling of activated carbon can be provided.

Drawings

Fig. 1 is a graph showing the particle size distribution of activated carbon used in the fibrous sheets of the examples and comparative examples of the present invention.

Detailed Description

The fiber sheet of the present invention is described in detail below.

The fibrous sheet of the present invention contains activated carbon, and the activated carbon has a particle size distribution in which the proportion of particles having a particle diameter of 10 μm or less is less than 15% and the proportion of particles having a particle diameter of 45 μm or more is less than 57%, and the content of the activated carbon per unit area mass of the fibrous sheet is 2.0 mass% or more and 8.0 mass% or less.

The fiber sheet of the present invention contains the activated carbon having the specific particle size distribution at the specific content, and therefore, the activated carbon can be prevented from falling off from the fiber sheet and the black color of the activated carbon is less noticeable, and therefore, the fiber sheet can have both excellent deodorizing performance and a clean feeling of the activated carbon.

The reason why the black color of the fibrous sheet becomes less noticeable by using the activated carbon having the above-described specific particle size distribution is as follows.

That is, in the case where there are many particles having a small particle size of 10 μm or less, the area per unit mass of the activated carbon is large, and in the case where there are many particles having a large particle size, the area per unit mass of the activated carbon is small because the particles of the activated carbon are large in the thickness direction. In addition, when the particle size is large, the activated carbon is locally enlarged, but since the region where the activated carbon is not present is also enlarged, the light transmittance is increased as a whole, and the appearance is bright. In this way, by containing the activated carbon having the specific particle size distribution at the specific content ratio, the black color of the fiber sheet is less noticeable.

In addition, the activated carbon having the above-mentioned specific particle size distribution also has an effect of being less likely to fall off from between the constituent fibers as long as it is a fibrous sheet such as a general nonwoven fabric.

The fiber sheet of the present invention can be suitably used for various sanitary materials requiring deodorization. Examples of such sanitary materials include toilet paper, toilet seat wiping sheets, and components of absorbent articles. Since these sanitary materials are particularly required to have deodorizing properties and a clean feeling, the effects of the fiber sheet of the present invention can be exhibited to a very high degree.

In addition, the fibrous sheet of the present invention has an advantage that stains (for example, excreta such as urine and feces) after use of toilet paper, a wiping sheet for a toilet seat, an absorbent article, and the like can be easily confirmed because the black color of the activated carbon is less noticeable.

In particular, since the absorbent article using the fiber sheet of the present invention as a constituent member uses the above fiber sheet, it is possible to achieve both excellent deodorizing performance and a clean feeling as an absorbent article.

In addition, when the fiber sheet of the present invention is a sheet-like member disposed at a position adjacent to or inside the absorbent body of the absorbent article or a core-covering sheet covering the absorbent core of the absorbent body, the fiber sheet of the present invention is disposed in the vicinity of the absorbent core that absorbs and retains excretory fluid such as urine that causes generation of odor, and therefore, the deodorizing performance can be more effectively exhibited. In addition, the absorbent article has an advantage that whether or not urination or the like is present is easily confirmed because the black color of the activated carbon in the fibrous sheet is not easily noticeable.

The absorbent article to which the fibrous sheet of the present invention is applied is not particularly limited, and examples thereof include disposable diapers, sanitary napkins, and (light) incontinence pads.

The fibrous sheet and the activated carbon applicable to the present invention are described in more detail below.

[ fiber sheet ]

In the present invention, the fiber sheet is not particularly limited as long as it has various characteristics according to various applications to which the fiber sheet is applied, and examples thereof include paper made of pulp fibers or the like, nonwoven fabrics made of hydrophilic fibers and/or hydrophobic resin fibers (for example, through-air nonwoven fabrics, spunlace nonwoven fabrics, spun bond nonwoven fabrics, and the like), woven fabrics, knitted fabrics, and the like.

The fibers constituting the fiber sheet are not particularly limited, and examples thereof include cellulose fibers such as pulp fibers, thermoplastic resin fibers (for example, olefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate), and hydrophilic fibers obtained by hydrophilizing the thermoplastic resin fibers. These fibers may be used alone or in combination of two or more.

In the present invention, the fiber sheetThe outer shape, various dimensions, mass per unit area, and the like of the fiber sheet can be any outer shape, various dimensions, mass per unit area, and the like according to various applications to which the fiber sheet is applied. In addition, the mass per unit area of the fiber sheet (excluding the activated carbon) is preferably 10g/m in view of the ease of exfoliation of the activated carbon, the ease of visualization of black, and the like²～50g/m²A mass per unit area within the range of (1), more preferably 15g/m²～25g/m²Mass per unit area within the range of (1). The mass per unit area can be measured in accordance with 5.2 of JIS L1906.

The method for producing the fiber sheet is not particularly limited, and the fiber sheet can be produced by a known production method such as a dry or wet paper making method, a dry or wet interlacing method, or a production method using a weaving machine or a knitting machine. Among these production methods, a wet papermaking method and a wet interlacing method (water-jet interlacing method) are preferable in terms of ease of uniformly dispersing the activated carbon in the fiber sheet. These production methods can be carried out by conventional methods.

[ activated carbon ]

In the present invention, the activated carbon contained in the fibrous sheet is a plurality of particles that function as a deodorant for physically adsorbing odor, and is disposed in the fibrous sheet in a substantially uniform dispersion. Each of the activated carbon particles has a porous structure having a large number of pores for adsorbing an odor component, and has a large specific surface area.

The raw material of the activated carbon is not particularly limited, and for example, known raw materials such as a carbonized product (i.e., coconut shell charcoal, bamboo charcoal, etc.) of coconut shell, bamboo, wood, etc., and coal can be used. Among these raw materials, from the viewpoint of preventing the activated carbon from falling off, it is preferable to use a carbonized material having a high hardness such as coconut shell carbon or bamboo charcoal. When such a carbonized material having a high hardness is used, since the activated carbon exposed on the surface of the fiber sheet also has a high hardness, the durability (i.e., friction durability) of the fiber sheet at the time of surface friction is further improved, and there is an advantage that the activated carbon is less likely to fall off.

The method for activating the activated carbon is not particularly limited, and a known activation method such as a gas activation method in which a gas such as steam or carbon dioxide is used for treatment at a high temperature, or a chemical activation method in which treatment is performed using zinc chloride, phosphoric acid, concentrated sulfuric acid, or the like can be used.

The particle form of the activated carbon is not particularly limited, and may be in the form of particles such as powder, granule, and granule, or in the form of fibrous particles.

In the present invention, the activated carbon has a particle size distribution in which the proportion (on a volume basis) of particles having a particle diameter of 10 μm or less is less than 15% and the proportion (on a volume basis) of particles having a particle diameter of 45 μm or more is less than 57%.

The particle size distribution of the activated carbon can be measured under predetermined conditions using a laser diffraction/scattering particle size distribution measuring apparatus (for example, horiba, LA-920). The measurement conditions of the particle size distribution are as follows.

Measurement cell: flow cell

Particle size basis: volume of

Dispersion medium: 90% by mass ethanol aqueous solution

Transmittance: 70 to 90 percent

Sample concentration: 0.1 percent of

In the present invention, the particle size distribution of the activated carbon is preferably such that the proportion of particles having a particle size of 20 μm or less is less than 53% except that the proportion of particles having a particle size of 10 μm or less is less than 15% and the proportion of particles having a particle size of 45 μm or more is less than 57%. When the proportion of the activated carbon having a small particle diameter of 20 μm or less is small, the black color of the activated carbon in the fibrous sheet can be made less conspicuous.

The particle size (average particle size) of the activated carbon is not particularly limited as long as it has the above-mentioned specific particle size distribution, and is, for example, a particle size of 20 μm to 35 μm.

Further, it is preferable that the activated carbon has a pore volume of 0.5mL/g or more and 1.5mL/g or less and an average pore diameter of 1.5nm or more and 4.0nm or less. When the activated carbon is a particle having such a specific pore volume and a specific average pore diameter and having a large total adsorption amount (i.e., high deodorizing ability), the predetermined deodorizing ability can be sufficiently exhibited even if the content of the activated carbon in the fibrous sheet is reduced. In this way, the fibrous sheet containing such activated carbon can make the black color of the activated carbon less noticeable while ensuring a predetermined deodorizing performance by reducing the content of the activated carbon as much as possible.

The pore volume and the average pore diameter are measured by a pore distribution measurement by mercury intrusion method and a BET multipoint method by nitrogen adsorption, which are generally performed, according to a common method.

In the present invention, the content of the activated carbon contained in the fibrous sheet is 2.0 mass% or more and 8.0 mass% or less, preferably 4.0 mass% or more and 8.0 mass% or less, and more preferably 4.0 mass% or more and 6.0 mass% or less, with respect to the mass per unit area of the fibrous sheet.

The fiber sheet of the present invention contains the activated carbon having the specific particle size distribution at a specific content ratio of 2.0 mass% or more and 8.0 mass% or less, and thereby the activated carbon can be prevented from falling off from the fiber sheet and the black color of the activated carbon is less noticeable.

The fiber sheet of the present invention is not limited to the above description, examples described below, and the like, and can be appropriately combined, substituted, modified, and the like without departing from the object and the gist of the present invention.

[ examples ] A method for producing a compound

The present invention will be described more specifically with reference to the following examples and comparative examples, but the present invention is not limited to these examples.

(1) Manufacture of fibrous sheets

Four kinds of activated carbons a to D having different particle sizes shown in table 1 and fig. 1 below were mixed together with a softwood kraft pulp (having a beating degree of 650mL), a dry paper strength enhancer (manufactured by seikagawa chemical industries, inc., photoston 705), 2.5 mass% of a wet paper strength agent (manufactured by seiko PMC), and 1 mass% of a retention aid (manufactured by Clariant Japan, Cartaretin) in the amounts shown in table 2 below (i.e., 4.0 to 12.0 mass%), and sufficiently stirred to obtain a raw material for papermaking.

Further, the obtained papermaking raw material was used to produce paper using a large square sheet machine (400mm square) (manufactured by kusho processor co., ltd.), and then the paper was dried by a 120 ℃ rotary dryer (manufactured by kusho processor co., ltd., at a speed of 1 m/min) to produce each of the fiber sheets of examples 1 to 5 and comparative examples 1 to 4.

[ TABLE 1 ]

TABLE 1

(2) Evaluation of fiber sheet

The degree of difficulty of the black color of the activated carbon and the releasability of the activated carbon of each fiber sheet were evaluated by measuring the brightness (L value) of the fiber sheet and the brightness (L value) after the crockfastness test with respect to each of the produced fiber sheets of examples 1 to 5 and comparative examples 1 to 4. The results of these evaluations are shown in table 2 below.

The measurement methods of the brightness (L value) of the fiber sheet and the brightness (L value) after the rubbing fastness test are as follows.

< method for measuring luminance (L value) >

The brightness (L value) of the fiber sheet was measured on a white calibration plate (CR-A43 (L value 96.7) manufactured by Konika Mento Kagaku K.K.) using a commercially available colorimeter (CR-300 manufactured by Konika Mento K.K.).

In addition, the greater the measured brightness (L value), the brighter the fibrous sheet appears, and the less noticeable the black color of the activated carbon.

< Brightness (L value) > < after Friction fastness test

The brightness (L value) after the rubbing fastness test was measured by rubbing the surface of the fiber sheet with a rubbing material having a film attached to the tip thereof using a commercially available rubbing fastness Tester (AB 301, manufactured by Tester industries, ltd.) according to the above-mentioned measurement method of < brightness (L value) > when the number of times the rubbing material was reciprocated was 20 times.

The test conditions using the crockmeter are as follows.

Test load: 200gf

Friction element: 20X 20mm, R45mm

Stroke: 120mm

Reciprocating speed: 30cpm

In the case where the activated carbon is detached from the fiber sheet by rubbing with a rubbing material, the detached activated carbon migrates to the side of the film attached to the tip of the rubbing material, and the brightness (L value) of the film becomes low (that is, the film becomes black due to adhesion of the activated carbon), so that the greater the brightness (L value) of the film after the rubbing fastness test, the less the activated carbon is detached.

In the section of the slip-off evaluation in table 2 below, the case where the luminance (L value) when the number of times of reciprocating the friction material was 20 was 80 or more was regarded as the passing mark circle mark, and the case where the luminance (L value) was less than 80 was regarded as the failing mark cross mark.

[ TABLE 2 ]

TABLE 2

As shown in table 2, the fiber sheets of examples 1 to 5 containing the activated carbon having the specific particle size distribution of the present invention at a specific content ratio all had a high brightness (L value), the black color of the activated carbon was not easily noticeable, and the activated carbon was not easily detached from the fiber sheets after the rubbing fastness test (after the rubbing material was reciprocated 20 times). That is, the fiber sheets of examples 1 to 5 were those having both excellent deodorizing performance and clean feeling of activated carbon.

On the other hand, as shown in table 2, the fiber sheets of comparative examples 1 to 4 in which the particle size distribution and the content of the activated carbon were not within the specific ranges of the present invention had low brightness (L value), the black color of the activated carbon was easily noticeable, and the activated carbon was easily exfoliated. That is, the fiber sheets of comparative examples 1 to 4 were not a fiber sheet having both excellent deodorizing performance and clean feeling of activated carbon.