WO2021153713A1 - Sheet and method for producing sheet - Google Patents

Abstract

Provided is a sheet having a substrate and a particle-containing layer, wherein the particle-containing layer comprises a polymer component (A) and particles (B) of mesoporous silica that supports a substance that contains platinum group atoms. The particle diameter D₅₀ at the 50% cumulative value on a volume basis in the particle size distribution of the particles (B) is not more than 70 µm.

Description

Sheets and sheet manufacturing methods

The present invention relates to a sheet and a method for manufacturing the sheet.

Mesoporous silica is a porous silica made of silicon dioxide having uniform and regular pores (mesopores) having a pore diameter of 0.5 to 50 nm and a large specific surface area. It is known that the powder composed of particles in which platinum particles are supported on this mesoporous silica has a property of decomposing and adsorbing ethylene and odorous substances.
For example, Patent Document 1 describes an ethylene decomposing agent obtained by supporting platinum or a platinum-containing compound on porous silica, and ethylene and the ethylene decomposing agent in the presence of oxygen and in an atmosphere of -1 to -40 ° C. Disclosed is a method for decomposing ethylene, which decomposes ethylene into carbon dioxide and water by contacting them.

Japanese Unexamined Patent Publication No. 2017-023889

Since the ethylene decomposing agent described in Patent Document 1 is a powder, it may contaminate other articles existing in the system, and there is a problem in handleability. Therefore, there is a demand for articles containing mesoporous silica having excellent handleability and various performances.

The present invention is a sheet having a substrate and a particle-containing layer containing particles having a particle size adjusted to a specific range, which is mesoporous silica carrying a substance containing a polymer component and a platinum group atom. In addition, a method for manufacturing the sheet is provided.
Specific aspects of the present invention are as follows [1] to [15].
[1] A sheet having a base material and a particle-containing layer.
The particle-containing layer contains a polymer component (A) and particles (B) which are mesoporous silica carrying a substance containing a platinum group atom.
_{A sheet in which the particle size D 50} at an integrated value of 50% based on the volume in the particle size distribution of the particles (B) is 70 μm or less.
[2] The ratio [D ₉₀ / D _{50 ] of the particle size D 90} to the particle size D ₅₀ at an integrated value of 90% based on the volume in the particle size distribution of the particles (B) is 60.0 or less. The sheet according to the above [1].
[3] The ratio [D ₁₀ / D _{50 ] of the particle size D 10} at the integrated value of 10% based on the volume in the particle size distribution of the particles (B) to the particle size D ₅₀ is 0.15 or more. The sheet according to the above [1] or [2].
[4] The sheet according to any one of the above [1] to [3] _{, wherein the particle size D 90} at an integrated value of 90% based on the volume in the particle size distribution of the particles (B) is 300 μm or less.
[5] The sheet according to any one of the above [1] to [4] _{, wherein the particle size D 10} at an integrated value of 10% based on the volume in the particle size distribution of the particles (B) is 0.010 μm or more.
[6] The sheet according to any one of the above [1] to [5], wherein the thickness of the base material is 1 to 1000 μm.
[7] The sheet according to any one of [1] to [6] above, wherein the air permeation resistance of the sheet is more than 0 seconds.
[8] The sheet according to any one of the above [1] to [7], wherein the base material contains at least a paper base material.
[9] The sheet according to any one of the above [1] to [8], wherein the polymer component (A) contains a hydroxyl group-containing polymer (A1).
[10] The sheet according to the above [9], wherein the hydroxyl group-containing polymer (A1) contains at least one selected from a polyvinyl alcohol-based resin, a phenol-based resin, and a polysaccharide.
[11] The sheet according to the above [10], wherein the polysaccharide contains at least one of starch and cellulose.
[12] The above [1] to [11], wherein the content of the particles (B) is 20 to 1000 parts by mass with respect to 100 parts by mass of the total amount of the polymer component (A) contained in the particle-containing layer. The sheet described in any one of the items.
[13] Any one of the above [1] to [12], wherein the content of the particles (B) per ^{1 m 2} of each particle-containing layer of the sheet is ^{0.10 to 20 g / m 2.} The sheet described in the section.
[14] Particles containing a polymer component (A) and particles (B) which are mesoporous silica carrying a substance containing a platinum group element, and having a volume-based integrated value of 50% in the particle size distribution of the particles (B). A composition for forming a particle-containing layer used for forming a particle-containing layer having a diameter D _{50 of 70 μm or less.}
[15] A method for producing a sheet, which comprises the following steps (1) and (2).
-Step (1): Mesoporous silica carrying a substance containing a polymer component (A) and a platinum group element, and having a particle size D ₅₀ of 70 μm or less at a volume-based integrated value of 50% in the particle size distribution. A step of preparing a composition for forming a particle-containing layer containing (B).
Step (2): A step of forming a particle-containing layer on at least one surface of the base material by using the composition for forming a particle-containing layer.

Unlike powder, the sheet of the preferred embodiment of the present invention can suppress contamination of other articles existing in the system, and the sheet of the more preferred embodiment further enhances various performances of mesoporous silica. It can be expressed more effectively than when used in the body.

It is a schematic cross-sectional view of the sheet which showed an example of the structure of the sheet of one aspect of this invention.

[Sheet configuration]
FIG. 1 is a schematic cross-sectional view of a sheet showing an example of the structure of a sheet according to one aspect of the present invention.
The sheet of the present invention may have a base material and a particle-containing layer. For example, as in the sheet 1a of FIG. 1A, the particle-containing layer 12 is laminated on one surface of the base material 11. It may have the same configuration. Further, as in the sheet 1b of FIG. 1B, the particle-containing layers 12a and 12b may be provided on both surfaces of the base material 11, respectively. The sheet 1b has a structure in which the base material 11 is sandwiched between the two particle-containing layers 12a and 12b.

The sheet of one aspect of the present invention may have a layer other than the base material and the particle-containing layer.
For example, in order to protect the particle-containing layer, a protective film may be laminated on the surface of the particle-containing layer. Specifically, the composition of the sheet 1a is protected on the surface of the particle-containing layer 12. The sheet 1c in which the films 13 are laminated may be used. Further, with respect to the configuration of the sheet 1b, the protective film 13a may be laminated on the surface of one particle-containing layer 12a, and the protective film 13b may be laminated on the surface of the other particle-containing layer 12b.
The protective films 13, 13a, and 13b are laminated during storage of the sheet 1c or sheet 1d, but are basically removed during use. However, when the protective film is a porous film having a large number of pores, the sheet having the porous film may be used as it is without removing the porous film.

Further, the sheet of one aspect of the present invention may have another layer between the base material and the particle-containing layer. However, from the viewpoint of effectively exhibiting various performances of mesoporous silica, a configuration in which a particle-containing layer is directly laminated on the surface of the base material is preferable.
Hereinafter, each layer of the sheet of one aspect of the present invention will be described in detail.

<Base material>
Examples of the base material contained in the sheet of one aspect of the present invention include high-quality paper, medium-quality paper, art paper, coated paper, kraft paper, glassin paper, cast-coated paper, imitation paper, matte paper, super art paper, and matte. Paper base materials such as coated paper, recycled paper, synthetic paper, paperboard, thick paper, Japanese paper; polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene Telephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, Resin base materials such as polystyrene films, polycarbonate films, polyimide films, fluororesin films; metal base materials made of aluminum, copper, silver, gold, iron, and alloys containing two or more of these; woven fabrics, non-woven fabrics; etc. Be done.

Further, the base material used in one aspect of the present invention may be a base material composed of a single layer, or may be a base material composed of a plurality of layers in which two or more layers are laminated.
Examples of the base material composed of multiple layers include laminated paper obtained by laminating a thermoplastic resin such as polyethylene on a paper base material, aluminum, copper, silver, gold, iron and the like on a paper base material and a resin-based base material. Examples thereof include a base material with a vapor deposition film formed by depositing the metal of.

The base material used in one embodiment of the present invention preferably contains at least a paper base material or a resin-based base material from the viewpoint of strength, handleability, and versatility of use, and has air permeability, water absorption, and biodegradability. From the viewpoint of high recyclability, it is more preferable to contain at least a paper base material, and it is further preferable to use a paper base material.
In the sheet of the present invention, the particle size D ₅₀ of the particles (B) contained in the particle-containing layer is adjusted to be within a predetermined range. By using a base material containing a paper base material in the sheet, the particles (B) can be easily unevenly distributed on the surface layer side of the particle-containing layer that comes into contact with air. As a result, it is possible to obtain a sheet capable of more effectively expressing various performances of mesoporous silica. Since the sheet contains a paper base material as a base material, it has water absorbency, can prevent contact with water with a substance containing a platinum group atom supported on the mesoporous silica, and has various performances of the mesoporous silica. It also has the effect of improving sustainability.

The base material used in one embodiment of the present invention from the viewpoint of making it easy for the particles (B) to be unevenly distributed on the surface layer side of the particle-containing layer in contact with air and making the sheet capable of more effectively exhibiting various performances of mesoporous silica. The air permeation resistance is preferably more than 0 seconds, more preferably 5 seconds or more, further preferably 10 seconds or more, still more preferably 15 seconds or more, particularly preferably 20 seconds or more, and further 25 seconds or more. It may be 30 seconds or more, 40 seconds or more, 50 seconds or more, 60 seconds or more, 70 seconds or more, or 80 seconds or more.
The air permeability resistance of the base material is 100,000 seconds or less, 50,000 seconds or less, 20,000 seconds or less, 10,000 seconds or less, 8,000 seconds or less, 6000 seconds or less, 5,000 seconds or less, 4000 seconds or less, 3000 seconds or less, 2500 seconds or less. , 2000 seconds or less, 1800 seconds or less, 1700 seconds or less, 1600 seconds or less, 1500 seconds or less, 1400 seconds or less, 1300 seconds or less, or 1200 seconds or less. As will be described later, it may not be possible to specify the upper limit of the air permeability resistance of the base material.
That is, the air permeation resistance of the base material is preferably more than 0 seconds and 5000 seconds or less, more preferably 5 to 4000 seconds, further preferably 10 to 3000 seconds, still more preferably 15 to 2500 seconds, and particularly preferably 20 to 20 to. It is 2000 seconds, and may be, for example, 25 to 1800 seconds, 30 to 1700 seconds, 40 to 1600 seconds, 50 to 1500 seconds, 60 to 1400 seconds, 70 to 1300 seconds, or 80 to 1200 seconds.

From the same viewpoint as above, the air permeation resistance of the sheet of one aspect of the present invention is preferably more than 0 seconds, more preferably 5 seconds or more, still more preferably 10 seconds or more, still more preferably 15 seconds or more. It is particularly preferably 20 seconds or longer, and may be 25 seconds or longer, 30 seconds or longer, 40 seconds or longer, 50 seconds or longer, 60 seconds or longer, 70 seconds or longer, or 80 seconds or longer.
The air permeation resistance of the sheet according to one aspect of the present invention is 100,000 seconds or less, 50,000 seconds or less, 20,000 seconds or less, 10,000 seconds or less, 8,000 seconds or less, 6000 seconds or less, 5000 seconds or less, 4000 seconds or less, 3000 seconds or less. Hereinafter, it may be 2500 seconds or less, 2000 seconds or less, 1800 seconds or less, 1700 seconds or less, 1600 seconds or less, 1500 seconds or less, 1400 seconds or less, 1300 seconds or less, or 1200 seconds or less. As will be described later, it may not be possible to specify the upper limit of the air permeability resistance of the base material.
That is, the air permeation resistance of the sheet according to one aspect of the present invention is preferably more than 0 seconds and 5000 seconds or less, more preferably 5 to 4000 seconds, still more preferably 10 to 3000 seconds, still more preferably 15 to 2500 seconds. Particularly preferably, it is 20 to 2000 seconds, and for example, 25 to 1800 seconds, 30 to 1700 seconds, 40 to 1600 seconds, 50 to 1500 seconds, 60 to 1400 seconds, 70 to 1300 seconds, or 80 to 1200 seconds. May be good.

In the present specification, the air permeation resistance means the time (seconds) required for air having a volume of 100 mL to pass through the test sheet, which is measured by a method based on the JIS P8117: 2009 Wang Lab test method. ..
However, for example, in the case of a base material containing a resin film and a sheet containing a resin film as the base material, air having a volume of 100 mL cannot pass through, and the value of air permeation resistance may be unmeasurable (infinite). .. Considering such a case, the upper limit of the air permeation resistance is not particularly limited.

The thickness of the base material used in one embodiment of the present invention is preferably 1 μm or more, more preferably 5 μm or more, still more preferably 5 μm or more, from the viewpoint of facilitating roll-to-roll processing and improving productivity. It is 10 μm or more, more preferably 20 μm or more, and may be 25 μm or more, 30 μm or more, 35 μm or more, or 40 μm or more.
From the same viewpoint, the thickness of the base material is preferably 1000 μm or less, more preferably 800 μm or less, still more preferably 500 μm or less, still more preferably 300 μm or less, and further 270 μm or less, 250 μm or less, 220 μm or less. , Or 200 μm or less.
That is, the thickness of the base material is preferably 1 to 1000 μm, more preferably 5 to 800 μm, further preferably 10 to 500 μm, still more preferably 20 to 300 μm, and for example, 25 to 270 μm, 30 to 250 μm. , 35 to 220 μm, or 40 to 200 μm.

<Particle-containing layer>
The particle-containing layer contained in the sheet of the present invention is referred to as particles (B) which are mesoporous silica carrying a polymer component (A) and a substance containing a platinum group atom (hereinafter, also simply referred to as “particles (B)”). The particle size distribution of the particles (B) satisfies the following requirement (I).
_{-Requirement (I): The particle size D 50} (hereinafter, also simply referred to as "particle size D ₅₀ of the particle (B)") at an integrated value of 50% based on the volume in the particle size distribution of the particle (B) is 70 μm or less. ..

Generally, as a method for producing a sheet containing particles (B), a base material is impregnated with a solution containing mesoporous silica particles, the solution is dried, and the particles (B) are incorporated into the base material. There is a way to make it.
However, there is a problem that the particles (B) are likely to fall off from the sheet obtained by this method. Therefore, there is a concern that the particles (B) may adhere to other articles existing together with the sheet in the system, resulting in contamination. In particular, it is difficult to use the sheet for food preservation from the viewpoint of contamination of food. That is, there is a problem in handleability and safety.

To solve the above problems of handleability and safety, a method of using a composition containing a polymer component (A) that plays a role of a binder together with the particles (B) can be considered. Examples of the method using the composition include a method of impregnating the composition with the base material to allow the particles (B) to be incorporated into the base material, and a method of applying the composition onto the base material to form a particle-containing layer. There is.
The first method, in which the composition is impregnated with the substrate to incorporate the particles (B) into the substrate, requires the preparation of a large amount of the composition. Further, depending on the lot, if the amount of the composition used at the time of impregnation is different, the amount of particles (B) taken in per unit area of the base material may be different. That is, it is difficult to keep the quality of the sheet constant due to the difference in lots at the time of manufacturing.

In the second method of applying the composition on a substrate to form a particle-containing layer, the particles (B) of mesoporous silica are likely to settle, so that the particles (B) are uniformly distributed. It has been found by the present inventors that it is often difficult to apply the particles.
Even if the coating can be applied, the mesoporous silica particles (B) are likely to be unevenly distributed on the substrate side of the particle-containing layer formed in the drying process. In various cases of the present inventors, it is difficult for a sheet in which such mesoporous silica particles (B) are present in the vicinity of the surface layer of the particle-containing layer to exhibit some of the various performances of the mesoporous silica. I found out during the examination. For example, one of the various performances of mesoporous silica is the effect of maintaining the freshness of food, but the effect is sufficiently exhibited on a sheet in which the presence ratio of mesoporous silica particles near the surface layer of the particle-containing layer is low. It turned out not to be done.

_{In response to such a problem, as specified in the above requirement (I), the particle size D 50} at a volume-based integrated value of 50% in the particle size distribution of the particles (B) contained in the particle-containing layer is 70 μm or less. It was found that the particles (B) can be unevenly distributed on the surface layer side of the particle-containing layer by adjusting the above. The sheet of the present invention has been completed based on the knowledge.

In one aspect of the present invention, from the above viewpoint, the particle size D ₅₀ of the particles (B) defined in the requirement (I) is preferably 50 μm or less, more preferably 30 μm or less, still more preferably 20 μm or less, still more preferably. Is 10 μm or less, particularly preferably 7 μm or less, and further, 6.5 μm or less, 6.0 μm or less, 5.7 μm or less, 5.5 μm or less, 5.2 μm or less, 5.0 μm or less, or 4.8 μm. good.
From the same viewpoint as above, the particle size D ₅₀ of the particles (B) is preferably 0.01 μm or more, more preferably 0.03 μm or more, more preferably 0.05 μm or more, still more preferably 0.07 μm or more. , More preferably 0.1 μm or more, particularly preferably 0.5 μm or more, and further preferably 1.1 μm or more, 1.6 μm or more, 2.1 μm or more, 2.3 μm or more, 2.5 μm or more, 2.7 μm. It may be the above, or 2.9 μm or more.
That is, the particle size D ₅₀ of the particles (B) is preferably 0.01 to 70 μm, more preferably 0.03 to 50 μm, more preferably 0.05 to 30 μm, still more preferably 0.07 to 20 μm, and further. It is preferably 0.1 to 10 μm, particularly preferably 0.5 to 7 μm, and is, for example, 1.1 to 6.5 μm, 1.6 to 6.0 μm, 2.1 to 5.7 μm, 2.3. It may be ~ 5.5 μm, 2.5 to 5.2 μm, 2.7 to 5.0 μm, or 2.9 to 4.8 μm.

Further, from the viewpoint that the particles (B) are unevenly distributed on the surface layer side of the particle-containing layer to make a sheet in which various performances of mesoporous silica are easily exhibited, the particle size distribution of the particles (B) used in one aspect of the present invention is defined. Further, it is preferable to satisfy at least one of the following requirements (II) and (III), and it is more preferable to satisfy both the following requirements (II) and (III).
-Requirement (II): The ratio [D ₉₀ / D _{50 ] of the particle size D 90} at the integrated value of 90% based on the volume in the particle size distribution of the particles (B) to the particle size D ₅₀ is 60.0 or less. Is.
-Requirement (III): The ratio [D ₁₀ / D _{50 ] of the particle size D 10} at the integrated value of 10% based on the volume in the particle size distribution of the particles (B) to the particle size D ₅₀ is 0.15 or more. Is.

In one aspect of the present invention, the ratio [D ₉₀ / D _{50 ] of the particle size D 90} to the particle size D ₅₀ of the particle (B) specified in the requirement (II) is 60.0 or less, and 50. It may be 0 or less, 45.0 or less, 30.0 or less, 20.0 or less, or 10.0 or less, but more preferably 3.50 or less, more preferably 3.20 or less, and more preferably 3.00. Below, it is more preferably 2.80 or less, still more preferably 2.50 or less, still more preferably 2.30 or less, and particularly preferably 1.95 or less.
The ratio [D ₉₀ / D ₅₀ ] is 1.01 or more, 1.02 or more, 1.03 or more, 1.04 or more, 1.05 or more, 1.06 or more, 1.07 or more, 1. It may be 08 or more, 1.09 or more, 1.10 or more, 1.15 or more, 1.20 or more, or 1.30 or more.
That is, the ratio [D ₉₀ / D ₅₀ ] of the particle size D ₉₀ and the particle size D ₅₀ of the particle (B) is, for example, 1.01 to 60.0, 1.02 to 50.0, 1.03 to. 45.0, 1.04 to 30.0, 1.05 to 20.0, 1.06 to 10.0, 1.07 to 3.50, 1.08 to 3.20, 1.09 to 3. It may be 00, 1.10 to 2.80, 1.15 to 2.50, 1.20 to 2.30, or 1.30 to 1.95.

In one aspect of the present invention, the ratio [D ₁₀ / D _{50 ] of the particle size D 10} and the particle size D ₅₀ of the particle (B) specified in the requirement (III) is preferably 0.20 or more, more preferably 0.20 or more. 0.23 or more, more preferably 0.25 or more, more preferably 0.27 or more, more preferably 0.30 or more, still more preferably 0.35 or more, still more preferably 0.40 or more, particularly preferably 0. It is .45 or more.
The ratio [D ₁₀ / D ₅₀ ] is preferably 0.99 or less, more preferably 0.98 or less, more preferably 0.97 or less, more preferably 0.96 or less, and more preferably 0.95. Below, it is more preferably 0.90 or less, still more preferably 0.85 or less, and particularly preferably 0.80 or less.
That is, the ratio [D ₁₀ / D ₅₀ ] of the particle size D ₁₀ to the particle size D ₅₀ of the particle (B) is preferably 0.20 to 0.99, more preferably 0.23 to 0.98, and more. It is preferably 0.25 to 0.97, more preferably 0.27 to 0.96, more preferably 0.30 to 0.95, still more preferably 0.35 to 0.90, still more preferably 0.40. It is ~ 0.85, particularly preferably 0.45 ~ 0.80.

_{In one aspect of the present invention, the particle size D 90} of the particles (B) is preferably 300 μm or less, more preferably 250 μm or less, and more, from the viewpoint of making the sheet more effectively exhibiting various performances of the mesoporous silica. It is preferably 200 μm or less, more preferably 150 μm or less, still more preferably 100 μm or less, still more preferably 50 μm or less, still more preferably 40 μm or less, still more preferably 30 μm or less, still more preferably 20 μm or less, still more preferably 15 μm or less. Particularly preferably, it is 10 μm or less, and further, it may be 9.5 μm or less, 8.0 μm or less, or 7.0 μm or less.
From the same viewpoint as above, the particle size D ₉₀ of the particles (B) is preferably 0.01 μm or more, more preferably 0.03 μm or more, more preferably 0.05 μm or more, and more preferably 0.07 μm or more. More preferably 0.1 μm or more, still more preferably 0.3 μm or more, still more preferably 0.5 μm or more, still more preferably 1.0 μm or more, still more preferably 1.5 μm or more, still more preferably 2.0 μm. As described above, it is particularly preferably 2.3 μm or more, and further, it may be 3.0 μm or more, 3.5 μm or more, or 4.0 μm or more.
That is, the particle size D ₉₀ of the particle (B) is preferably 0.01 to 300 μm, more preferably 0.03 to 250 μm, more preferably 0.05 to 200 μm, more preferably 0.07 to 150 μm, still more preferably. Is 0.1 to 100 μm, more preferably 0.3 to 50 μm, still more preferably 0.5 to 40 μm, still more preferably 1.0 to 30 μm, even more preferably 1.5 to 20 μm, still more preferably 2. It is 0.0 to 15 μm, particularly preferably 2.3 to 10 μm, and may be, for example, 3.0 to 9.5 μm, 3.5 to 8.0 μm, or 4.0 to 7.0 μm.

In one aspect of the present invention, the particle size D ₁₀ of the particles (B) is preferably 0.010 μm or more, more preferably 0. 012 μm or more, more preferably 0.015 μm or more, even more preferably 0.017 μm or more, particularly preferably 0.019 μm or more, and further 0.030 μm or more, 0.050 μm or more, 0.070 μm or more, 0.10 μm. As mentioned above, it may be 0.50 μm or more, 1.0 μm or more, 1.2 μm or more, 1.5 μm or more, or 1.7 μm or more.
From the same viewpoint as above, the particle size D ₁₀ of the particles (B) is preferably 6.5 μm or less, more preferably 6.0 μm or less, still more preferably 5.5 μm or less, still more preferably 5.2 μm. Below, it is particularly preferably 5.0 m or less, and further, 4.8 μm or less, 4.6 μm or less, 4.4 μm or less, 4.2 μm or less, 4.0 μm or less, 3.8 μm or less, 3.6 μm or less, 3 It may be 0.4 μm or less, or 3.2 μm or less.
That is, the particle size D ₁₀ of the particles (B) is preferably 0.010 to 6.5 μm, more preferably 0.012 to 6.0 μm, still more preferably 0.015 to 5.5 μm, and even more preferably 0. It is .017 to 5.2 μm, particularly preferably 0.019 to 5.0 μm, and is, for example, 0.030 to 4.8 μm, 0.050 to 4.6 μm, 0.070 to 4.4 μm, 0. It may be 10 to 4.2 μm, 0.50 to 4.0 μm, 1.0 to 3.8 μm, 1.2 to 3.6 μm, 1.5 to 3.4 μm, or 1.7 to 3.2 μm.

In the present specification, the particle size distribution of the particles (B) can be measured using, for example, a laser diffraction type particle size distribution meter (manufactured by Malvern Instruments, product name “Mastersizer 3000”).
Then, based on the measured particle size distribution, as D ₁₀ particle size during accumulation ratio by volume based from the side the smaller particle size is 10%, the particle diameter when cumulative rate by volume basis is 50% The particle size can be calculated as D ₅₀ and when the integration rate based on the volume is 90% as D _90.

^{The content of the particles (B) per 1 m 2} of each particle-containing layer contained in the sheet of one aspect of the present invention is preferably from the viewpoint of making the sheet easily exhibiting various performances of mesoporous silica. 0.10 g / m ² or more, more preferably 0.15 g / m ² or more, still more preferably 0.20 g / m ² or more, even more preferably 0.25 g / m ² or more, particularly preferably 0.30 g / m ² or more, 0.32 g / m ² or more, 0.34 g / m ² or more, 0.36 g / m ² or more, 0.38 g / m ² or more, 0.40 g / m ² or more, 0.44 g / ^{m 2} or more, 0.48 g / ^{m 2} or more, 0.50 g / ^{m 2} or more, 0.55 g / ^{m 2} or more, 0.60 g / ^{m 2} or more, 0.70 g / ^{m 2} or more, 0.80 g / m ^{It may be 2} or more, 0.90 g / m ² or more, or 1.00 g / m 2 or more.
Further, from the viewpoint of suppressing dropping, the content of the particles (B) per ^{1 m 2 of each particle-containing layer of the sheet is preferably 20 g / m 2} or less, more preferably 16 g / m ² or less, and further. It is preferably 14 g / m ² or less, more preferably 12 g / m ² or less, particularly preferably 10 g / m ² or less, and further ^{preferably 9.8 g / m 2} or less, 9.7 g / m ² or less, 9.6 g. / ^{m 2} or less, 9.5 g / ^{m 2} or less, 9.0 g / ^{m 2} or less, 8.0 g / ^{m 2} or less, 7.0 g / ^{m 2} or less, 6.0 g / ^{m 2} or less, 5.0 g / m ^{It may be 2} or less, 4.5 g / m ² or less, 4.0 g / m ² or less, 3.5 g / m ² or less, 3.0 g / m ² or less, or 2.5 g / m 2 or less.
That is, the content of the particles (B) per ^{1 m 2} of each particle-containing layer contained in the sheet is ^{preferably 0.10 to 20 g / m 2} , more preferably 0.15 to 16 g / m 2, and even more preferably 0.15 to 16 g / m ² . Is 0.20 to 14 g / m ² , more preferably 0.25 to 12 g / m ² , particularly preferably 0.30 to 10 g / m ² , and for example, 0.32 to 9.8 g / m. ^{2, 0.34 ~ 9.7g / m 2} , 0.36 ~ 9.6g / m 2, 0.38 ~ 9.5g / m 2, 0.40 ~ 9.0g / m 2, 0.44 ~ 8.0 g / m ² , 0.48 to 7.0 g / m ² , 0.50 to 6.0 g / m ² , 0.55 to 5.0 g / m ² , 0.60 to 4.5 g / m ² , 0.70 to 4.0 g / m ² , 0.80 to 3.5 g / m ² , 0.90 to 3.0 g / m ² , or 1.00 to 2.5 g / m ² .

The above-mentioned "content of particles (B) per ^{1 m 2} of each particle-containing layer" means the content of particles (B) per ^{1 m 2 in one particle-containing layer.} For example, in the case of the particle-containing layer 12a and the particle-containing layer 12b on both sides of the base material 11 as in the sheet 1b shown in FIG. 1B, each layer of the particle-containing layer 12a and the particle-containing layer 12b is used. It is preferable that the content of the particles (B) per 1 m ^{2 belongs to the above range.
The "content of particles (B) per 1 m 2 of the} particle-containing layer" is the amount (unit: g / m) of the composition for forming the particle-containing layer, which is the material for forming each particle-containing layer, before drying. ² ) (hereinafter, also simply referred to as "coating amount before drying") can be calculated from the following formula.
[Content of particles (B) per ^{1 m 2 of} particle-containing layer ^{(g / m 2} )] = [Coating amount before drying (g / m ² )] x [Content ratio of active ingredient in composition] × [Mass of particles (B) in composition] / [Mass of active ingredient in composition]

^{The mass per 1 m 2} of each particle-containing layer of the sheet of one aspect of the present invention ^{is preferably 0.01 g / m 2} or more from the viewpoint of making the sheet easily exhibiting various performances of mesoporous silica. , more preferably 0.03 g / ^{m 2} or more, more preferably 0.05 g / ^{m 2} or more, even more preferably at 0.10 g / ^{m 2} or more, further, 0.20 g / ^{m 2} or more, 0.30 g / ^{M 2} or more, 0.40 g / m ² or more, 0.50 g / m ² or more, 0.60 g / m ² or more, 0.70 g / m ² or more, 0.80 g / m ² or more, 0.90 g / m ^{It may be 2} or more, or 1.00 g / m 2 or more.
Further, from the viewpoint of suppressing falling off, ^{the mass of each particle-containing layer per 1 m 2 of} the sheet is preferably 150 g / m ² or less, more preferably 100 g / m ² or less, still more preferably 70 g / m ^2. or less, more further preferably not 50 g / ^{m 2} or less, further, 45 g / ^{m 2} or less, 40 g / ^{m 2} or less, 35 g / ^{m 2} or less, 30 g / ^{m 2} or less, 27 g / ^{m 2} or less, 25 g / ^{m 2} Hereinafter, it may be 22 g / m ² or less, 20 g / m ² or less, or 18 g / m ^{2 or less.}
In other words, the sheet has a weight of 1 m ² per each particle containing layer is preferably 0.01 ~ 150g / ^{m 2,} more preferably 0.03 ~ 100g / ^{m 2,} more preferably 0.05 ~ 70 g / M ² , more preferably 0.10 to 50 g / m ² , and also, for example, 0.20 to 45 g / m ² , 0.30 to 40 g / m ² , 0.40 to 35 g / m ² , 0.50 to 30 g / m ² , 0.60 to 27 g / m ² , 0.70 to 25 g / m ² , 0.80 to 22 g / m ² , 0.90 to 20 g / m ² , or 1.00 to It may be 18 g / m ^{2.
The above-mentioned "mass per 1 m 2} of each particle-containing layer" means the mass per ^{1 m 2} of one particle-containing layer. For example, in the case of the particle-containing layer 12a and the particle-containing layer 12b on both sides of the base material 11 as in the sheet 1b shown in FIG. 1B, 1 m of each of the particle-containing layer 12a and the particle-containing layer 12b. It is preferable that the mass per ^{2 belongs to the above range.}

The particle-containing layer of the sheet of one aspect of the present invention contains the polymer component (A) and the particles (B) which are mesoporous silica carrying a substance containing a platinum group element, and the particle size distribution of the particles (B). It can be formed from a particle-containing layer forming composition used for forming a particle-containing layer having _{a particle size D 50} of 70 μm or less at an integrated value of 50% based on the volume in the above.
Hereinafter, the particle-containing layer contained in the sheet of one aspect of the present invention and each component contained in the composition for forming the particle-containing layer, which is a material for forming the particle-containing layer, will be described.

[Polymer component (A)]
The polymer component (A) is fixed in the layer so that the particles (B) do not fall off from the particle-containing layer, and the particles (B) are uniformly dispersed in the particle-containing layer. It is a component for maintaining the shape.
As the polymer component (A) used in one embodiment of the present invention, various resins can be used, for example, acrylic resin, urethane resin, polyester resin, polyvinyl alcohol resin, phenol resin, epoxy resin, acetic acid. Examples thereof include vinyl resins, polyvinylpyrrolidone-based resins, and polysaccharides.
These polymer components (A) may be used alone or in combination of two or more.

The number average molecular weight of the polymer component (A) is preferably 100 to 1,000,000, more preferably 1,000 to 600,000, still more preferably 3,000 to 300,000, and even more preferably 5. It is between 000 and 200,000.

Among these, the polymer component (A) used in one embodiment of the present invention preferably contains a hydroxyl group-containing polymer (A1).
By using the hydroxyl group-containing polymer (A1), the particles (B) whose particle size distribution has been adjusted as described above can be unevenly distributed on the surface layer side of the formed particle-containing layer. As a result, it is possible to obtain a sheet capable of more effectively exhibiting various performances (for example, mold resistance, freshness retention, etc.) of mesoporous silica. Further, the hydroxyl group-containing polymer (A1) has good compatibility with the silanol group of mesoporous silica, and can be expected to have an effect of suppressing the precipitation of the particles (B). Further, when the composition for forming a particle-containing layer is applied on the base material, a hydrogen bond is formed between the hydroxyl group-containing polymer (A1) and the particles (B), so that the particles (B) are prevented from falling off. Can be effectively suppressed. In particular, when a paper base material is included as the base material, the adhesion between the paper base material and the particle-containing layer can be further improved.

From the above viewpoint, the content ratio of the hydroxyl group-containing polymer (A1) in the polymer component (A) is the total amount (100 mass) of the polymer component (A) contained in the particle-containing layer or the composition for forming the particle-containing layer. %), preferably 50 to 100% by mass, more preferably 70 to 100% by mass, still more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and particularly preferably 95 to 100% by mass. Is.

Examples of the hydroxyl group-containing polymer (A1) used in one embodiment of the present invention include polyvinyl alcohol-based resins such as polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, and ethylene / vinyl alcohol copolymers; polyethylene-based polyols, polypropylene-based polyols, and the like. Polyol-based resins such as polybutadiene-based polyols, acrylic polyols, polyester polyols, and polyether polyols; hydroxyl group-containing acrylic resins such as poly (2-hydroxyethyl methacrylate), polyhydroxypropyl acrylate, and polyhydroxyethyl acrylate; phenol-based resins; cellulose , Cellulite nitrate, Methyl cellulose, Ethyl cellulose, Celluloid, Viscoa rayon, Regenerated cellulose, Cellophane, Cupra, Cuprammonium rayon, Cuprophan, Bemberg, Hemicelle roll, Starch, Acetal pectin, Dextrin, Dextran, Glycogen, Pectin, Chitin, Chitosan, Arabia Polysaccharides such as gum, guar gum, locust bean gum, acacia gum; and the like can be mentioned.
These hydroxyl group-containing polymers (A1) may be used alone or in combination of two or more.

Among these, the hydroxyl group-containing polymer (A1) used in one embodiment of the present invention preferably contains one or more selected from polyvinyl alcohol-based resins, phenol-based resins, and polysaccharides, and is preferably polyvinyl alcohol-based resins and poly. It is more preferable to contain one or more selected from sugars.
The polysaccharide preferably contains at least one of starch and cellulose, and starch is more preferable, from the viewpoint of high film-forming property and safety. In particular, starch can exhibit excellent film-forming properties even with a small amount of addition.

In one aspect of the present invention, from the viewpoint of retaining the particles (B) in the particle-containing layer and suppressing the falling off of the particles (B), the total mass (100% by mass) of the particle-containing layer or the composition for forming the particle-containing layer. The content of the polymer component (A) with respect to the total amount (100% by mass) of the active component of the product is preferably 5% by mass or more, more preferably 8% by mass or more, still more preferably 10% by mass or more, still more preferably. Is 12% by mass or more, particularly preferably 15% by mass or more, and further, 16% by mass or more, 18% by mass or more, 20% by mass or more, 22% by mass or more, 24% by mass or more, 26% by mass or more, 28% by mass. % Or more, 30% by mass or more, 32% by mass or more, or 34% by mass or more.
In addition, the particles (B) are less likely to be buried in the particle-containing layer and are easily precipitated on the surface layer side, and it is possible to avoid directly coating the polymer component (A) with a substance containing a platinum group atom supported on mesoporous silica. In this state, the content of the polymer component (A) is preferably 85 from the viewpoint of unevenly distributing the particles on the surface (α) side of the particle-containing layer to more effectively exhibit various performances of the mesoporous silica. Mass% or less, more preferably 80% by mass or less, still more preferably 75% by mass or less, still more preferably 70% by mass or less, particularly preferably 65% by mass or less, and further 62% by mass or less, 60% by mass or less. , 58% by mass or less, 56% by mass or less, 54% by mass or less, 52% by mass or less, 50% by mass or less, 48% by mass or less, 46% by mass or less, or 44% by mass or less.
That is, from these viewpoints, the content of the polymer component (A) is preferably 5 to 85% by mass, more preferably 8 to 80% by mass, still more preferably 10 to 75% by mass, and even more preferably. It is 12 to 70% by mass, particularly preferably 15 to 65% by mass, and is, for example, 16 to 62% by mass, 18 to 60% by mass, 20 to 58% by mass, 22 to 56% by mass, and 24 to 54% by mass. , 26-52% by mass, 28-50% by mass, 30-48% by mass, 32-46% by mass, or 34-44% by mass.
In addition, in this specification, the "active ingredient" of the composition for forming a particle-containing layer refers to the component contained in the formed particle-containing layer among the components contained in the composition for forming a particle-containing layer. , Specifically, it means a component other than the diluting solvent.

[Particle (B)]
The particles (B) used in one embodiment of the present invention are particles made of mesoporous silica carrying a substance containing a platinum group atom. The particles (B) used in one aspect of the present invention are preferably particles made of mesoporous silica in which a substance containing a platinum group atom is carried in the pores. By placing a substance containing a platinum group atom in the pores of mesoporous silica, it is possible to avoid a state in which the substance is directly coated with the polymer component (A), and the function of the substance as a catalyst can be effectively exhibited. ..
As described above, the particle size distribution of the particles (B) is adjusted so as to satisfy at least the above requirement (I), and further adjusted to satisfy the above requirements (II) and (III). Is preferable.

The substance containing a platinum group atom supported on mesoporous silica may be a substance containing at least one selected from platinum, rhodium, ruthenium, palladium, and iridium, and is a single particle made of one of these metals. It may be an alloy particle such as a ruthenium / palladium alloy or a platinum / ruthenium alloy.
Among these, the substance containing a platinum group atom is preferably a substance containing a platinum atom. That is, the particles (B) used in one aspect of the present invention preferably include particles (B1) that are mesoporous silica carrying a substance containing a platinum atom.
The content ratio of the particles (B1) in the particles (B) used in one aspect of the present invention is the total amount (100% by mass) of the particles (B) contained in the particle-containing layer or the composition for forming the particle-containing layer. It is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, still more preferably 95 to 100% by mass, and particularly preferably 98 to 100% by mass.

The average particle size of the substance containing platinum group atoms supported on the mesoporous silica is such that the substance is easily supported in the pores of the mesoporous silica and the substance is directly coated on the polymer component (A). From the viewpoint of avoiding it and effectively expressing the function as a catalyst and increasing the specific surface area, it is preferably 10.0 nm or less, more preferably 7.0 nm or less, still more preferably 5.0 nm or less, and further. , 4.5 nm or less, 4.0 nm or less, 3.5 nm or less, or 3.0 nm or less.
The average particle size of the substance containing a platinum group atom supported on the mesoporous silica is preferably 0.1 nm or more from the viewpoint of preventing the substance from falling off from the mesoporous silica and sufficiently exhibiting the function as a catalyst. It is more preferably 0.5 nm or more, further preferably 0.7 nm or more, and further preferably 0.8 nm or more, 1.0 nm or more, 1.2 nm or more, or 1.5 nm or more.
That is, the average particle size of the substance containing a platinum group atom supported on mesoporous silica is preferably 0.1 to 10.0 nm, more preferably 0.5 to 7.0 nm, and further preferably 0.7 to 5. It is 0.0 nm, and may be, for example, 0.8 to 4.5 nm, 1.0 to 4.0 nm, 1.2 to 3.5 nm, or 1.5 to 3.0 nm.
In the present specification, the average particle size of a substance containing a platinum group atom is the particle size of 10 substances arbitrarily selected when observing an arbitrary region using a transmission electron microscope (TEM). Means the average value.

The shape of the pores of the mesoporous silica is not particularly limited, but is preferably a shape having an average aspect ratio of 5 or more (more preferably tubular). The pores having such a shape easily take in air into the pores due to the capillary phenomenon, and easily come into contact with a substance containing a platinum group atom supported in the pores. As a result, it is possible to obtain a sheet in which various performances of mesoporous silica are easily exhibited.
The above-mentioned tubular shape is a pipe shape having substantially the same cross section, and the central axis may be a cylindrical shape extending linearly or a spiral shape having the central axis extending spirally. The shape may be such that the central axis extends randomly.

The average pore diameter of the mesoporous silica is preferably 0.5 to 50 nm, more preferably 0.7 to 15 nm, and even more preferably 1.0 to 10 nm.
In this specification, the average pore diameter of mesoporous silica can be calculated by the BJH method by nitrogen adsorption / desorption.

From the viewpoint of effectively expressing the function as a catalyst, in the particles (B) used in one embodiment of the present invention, the average particle size of the substance containing the platinum group atom supported on the mesoporous silica and the average of the mesoporous silica. It is preferable that the ratio to the pore diameter [average particle diameter of the substance containing platinum group atoms / average pore diameter of mesoporous silica] is smaller than 1.

The specific surface area of the mesoporous silica is preferably 300 to 2000 m ² / g, more preferably 400 to 1700 m ² / g, and further preferably 500 to 1500 m ² / g.
In this specification, the specific surface area of mesoporous silica can be calculated by the BET method by nitrogen adsorption / desorption.

The method for producing mesoporous silica is not particularly limited, and the mesoporous silica can be produced by a general method. For example, an inorganic raw material and an organic raw material are mixed and subjected to a shrink polymerization reaction to use an organic substance as a template. Mesoporous silica can be obtained by forming a composite of an organic substance and an inorganic substance having an inorganic skeleton formed around them, and then removing the organic substance from the complex.
Examples of the inorganic raw material include alkoxysilanes such as tetramethoxysilane, tetraethoxysilane and tetrapropoxysilane, sodium silicate, kanemite, silica, and silica-metal composite oxides. Moreover, as the said organic raw material, for example, various surfactants and the like can be mentioned.
When mixing the inorganic raw material and the organic raw material, water or an organic solvent may be added.
The reaction conditions for the polycondensation reaction are appropriately set depending on the type of the inorganic raw material or the organic raw material used, but the reaction is preferably carried out at 0 to 100 ° C. for 1 to 24 hours.
Further, examples of the removal of organic substances include a method of firing at about 400 to 800 ° C., a method of treating with a solvent such as water or alcohol, and the like.

Examples of the method of supporting a substance containing a platinum group atom on mesoporous silica include a method of reducing a mixture of a raw material compound containing a platinum group atom and mesoporous silica. Specifically, a method of preparing an aqueous solution of a raw material compound containing a platinum group atom, impregnating the aqueous solution with mesoporous silica, drying at 50 to 200 ° C., and then reducing the mixture can be mentioned.

As the particles (B), commercially available mesoporous silica carrying a substance containing a platinum group atom may be used.
The mesoporous silica particles produced as described above or the commercially available mesoporous silica particles satisfy the above requirement (I) (preferably, further satisfy the above requirements (II) and (III). ), It is preferable to adjust the particle size distribution.
In general, the mesoporous silica particles produced as described above and the commercially available mesoporous silica particles have a large particle size, and therefore the particle size distribution often does not satisfy the requirement (I).
Therefore, it is preferable to pulverize these particles with a bead mill or the like to adjust the particles to have a particle size distribution satisfying the above requirements (I) to (III).
By appropriately setting the bead diameter, rotation speed, and rotation time of the bead mill, the particles (B) having a particle size distribution satisfying the above requirements (I) to (III) can be easily adjusted.

In one aspect of the present invention, the particle-containing layer or particles are made from the viewpoint of making it difficult for the particles (B) to be buried in the particle-containing layer and facilitating precipitation on the surface layer side so that various performances of the mesoporous silica can be more effectively exhibited. The content of the particles (B) is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, still more preferably 70 parts by mass with respect to 100 parts by mass of the total amount of the polymer component (A) contained in the composition for forming a containing layer. By mass or more, more preferably 80 parts by mass or more, particularly preferably 95 parts by mass or more, and further, 100 parts by mass or more, 110 parts by mass or more, 120 parts by mass or more, 130 parts by mass or more, 140 parts by mass or more, Alternatively, it may be 150 parts by mass or more.
Further, from the viewpoint of retaining the particles (B) in the particle-containing layer to suppress the falling off of the particles (B), suppressing the overlap between the particles, and more effectively expressing the various performances of the mesoporous silica. The content of the particles (B) is preferably 1000 parts by mass or less, more preferably 850 parts by mass or less, still more preferably 700 parts by mass or less, based on 100 parts by mass of the total amount of the polymer component (A). More preferably 550 parts by mass or less, particularly preferably 400 parts by mass or less, and further preferably 350 parts by mass or less, 300 parts by mass or less, 280 parts by mass or less, 260 parts by mass or less, 240 parts by mass or less, or 220 parts by mass or less. May be.
That is, from these viewpoints, the content of the particles (B) is preferably 20 to 1000 parts by mass, more preferably 50 to 850 parts by mass, based on 100 parts by mass of the total amount of the polymer component (A). It is more preferably 70 to 700 parts by mass, still more preferably 80 to 550 parts by mass, particularly preferably 95 to 400 parts by mass, and for example, 100 to 350 parts by mass, 110 to 300 parts by mass, 120 to 280 parts by mass. Parts, 130 to 260 parts by mass, 140 to 240 parts by mass, or 150 to 220 parts by mass may be used.

In one aspect of the present invention, when the average particle size of the particles (B) is less than 0.1 μm, the content of the particles (B) is a sheet capable of more effectively expressing various performances of the mesoporous silica. From the viewpoint, it is preferably 100 parts by mass or more, more preferably 120 parts by mass or more, still more preferably 120 parts by mass or more, based on 100 parts by mass of the total amount of the polymer component (A) contained in the particle-containing layer or the composition for forming the particle-containing layer. It may be 150 parts by mass or more, more preferably 170 parts by mass or more, particularly preferably 190 parts by mass or more, and further, 200 parts by mass or more, 210 parts by mass or more, 220 parts by mass or more, or 230 parts by mass or more. Further, it is preferably 1000 parts by mass or less, more preferably 850 parts by mass or less, further preferably 700 parts by mass or less, still more preferably 550 parts by mass or less, particularly preferably 500 parts by mass or less, and further preferably 450 parts by mass or less. , 420 parts by mass or less, 400 parts by mass or less, or 370 parts by mass or less.
That is, when the average particle diameter of the particles (B) is less than 0.1 μm, the content of the particles (B) is preferably 100 to 1000 parts by mass with respect to 100 parts by mass of the total amount of the polymer component (A). , More preferably 120 to 850 parts by mass, still more preferably 150 to 700 parts by mass, even more preferably 170 to 550 parts by mass, particularly preferably 190 to 500 parts by mass, and for example, 200 to 450 parts by mass. It may be 210 to 420 parts by mass, 220 to 400 parts by mass, or 230 to 370 parts by mass.

[Other active ingredients]
The particle-containing layer and the composition for forming the particle-containing layer, which is a material for forming the particle-containing layer, contain active ingredients other than the polymer component (A) and the particles (B) as long as the effects of the present invention are not impaired. You may.

However, in one aspect of the present invention, the total content of the polymer component (A) and the particles (B) is the total mass (100% by mass) of the particle-containing layer or the total amount of the active component of the composition for forming the particle-containing layer. With respect to (100% by mass), it is preferably 60 to 100% by mass, more preferably 70 to 100% by mass, still more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and particularly preferably 95 to 100% by mass. It is 100% by mass.

Examples of the active ingredient other than the polymer component (A) and the particles (B) include an inorganic binder, a sedimentation inhibitor, a thixotropy and the like.
Examples of the inorganic binder include alumina, zirconia, silica and the like.
Examples of the sedimentation inhibitor include fumed silica, alumina and the like.
Examples of the thixotropy include a copolymer of maleic anhydride and α-olefin (ethylene, propylene, etc.) or styrene.
Further, the composition for forming a particle-containing layer includes an insect repellent, a fragrance, a moisture-proof agent, a sizing agent, a coloring agent, a filler, a fixing agent, a dry paper strength agent, a wet paper strength agent, etc., depending on the use of the sheet. May be contained.

However, in one aspect of the present invention, the content of the inorganic binder (particularly alumina) may be reduced as a component contained in the particle-containing layer and the composition for forming the particle-containing layer.
The specific content of the inorganic binder (particularly alumina) is 100 parts by mass of the total amount of the polymer component (A) and the particles (B) contained in the particle-containing layer or the composition for forming the particle-containing layer. , Less than 50 parts by mass, less than 20 parts by mass, less than 10 parts by mass, less than 5 parts by mass, less than 1 part by mass, less than 0.1 parts by mass, less than 0.01 parts by mass, or less than 0.001 parts by mass.
In particular, if the content of alumina is large, the dispersibility may be lowered, and when the sheet is cut to an appropriate size, there is a concern that the cutting blade may be worn. Therefore, the smaller the alumina content, the more preferable.

Further, the composition for forming a particle-containing layer used in one aspect of the present invention may contain a sedimentation inhibitor, but the particle size distribution of the particles (B) is adjusted so as to satisfy at least the above requirement (I). Therefore, it is not necessary to contain an anti-sediment agent.
The content of the anti-settlement agent is less than 50 parts by mass, 20 parts by mass with respect to 100 parts by mass of the total amount of the polymer component (A) and the particles (B) contained in the particle-containing layer or the composition for forming the particle-containing layer. Less than parts by mass, less than 10 parts by mass, less than 5 parts by mass, less than 1 part by mass, less than 0.1 parts by mass, less than 0.01 parts by mass, or less than 0.001 parts by mass.

[Diluting solvent]
The composition for forming a particle-containing layer, which is a material for forming the particle-containing layer, is preferably in the form of a solution by further adding a diluting solvent.
Examples of the diluting solvent include water, ethanol, isopropyl alcohol, methyl ethyl ketone and the like, and among these, water is preferable.

The solid content (active ingredient) concentration of the solution of the composition for forming a particle-containing layer used in one embodiment of the present invention is preferably 0.01% by mass or more from the viewpoint of improving the drying efficiency with respect to a desired coating amount. It is preferably 0.05% by mass or more, more preferably 0.1% by mass or more.
Further, from the viewpoint of suppressing the occurrence of drying inhibition due to the formation of a film only on the outermost layer portion, which may occur when the coating film is dried, the solid content (active ingredient) concentration of the solution of the particle-containing layer forming composition is set. It is preferably 50% by mass or less, more preferably 20% by mass or less, and further preferably 10% by mass or less.
That is, from these viewpoints, the solid content (active ingredient) concentration of the solution of the composition for forming a particle-containing layer is preferably 0.01 to 50% by mass, more preferably 0.05 to 20% by mass, and even more preferably. It is 0.1 to 10% by mass.

Further, the composition for forming a particle-containing layer used in one aspect of the present invention may contain acids such as hydrochloric acid, nitric acid and sulfuric acid, but from the viewpoint of preventing the occurrence of rust in the sheet manufacturing machine and the sheet. From the viewpoint of processability at the time of producing, the smaller the content of acid and base is, the more preferable.
From the above viewpoint, the pH of the particle-containing layer forming composition used in one embodiment of the present invention is preferably 3.0 or higher, more preferably 4.0 or higher, still more preferably 5.0 or higher, and even more preferably 5.0 or higher. It is 5.5 or more, preferably 11.0 or less, more preferably 10.0 or less, still more preferably 9.0 or less, still more preferably 8.5 or less.
That is, the pH of the particle-containing layer forming composition is preferably 3.0 to 11.0, more preferably 4.0 to 10.0, still more preferably 5.0 to 9.0, and even more preferably. It is 5.5 to 8.5.
In this specification, the pH of the composition for forming a particle-containing layer means a value measured by the method described in Examples.

<Protective film>
The sheet of one aspect of the present invention may further have a protective film.
The protective film protects the surface of the particle-containing layer so that the surface of the particle-containing layer does not come into direct contact with air and reduce the catalytic action of the particles (B) during storage. It is provided in.

As the protective film used in one aspect of the present invention, for example, a protective film having a release agent layer formed from a release material on the surface of the support is preferable.
Examples of the support for the protective film include paper base materials such as glassin paper, coated paper, and high-quality paper, laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper base materials, polyethylene terephthalate resin, and polybutylene terephthalate. Examples thereof include a resin, a polyester resin film such as polyethylene naphthalate resin, and a resin film such as a polyolefin resin film such as polypropylene resin and polyethylene resin.
Among these, a support having a high gas barrier property is preferable.
Examples of the release agent include silicone-based resins, olefin-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluororesins.

The thickness of the protective film used in one aspect of the present invention is appropriately set, but is preferably 10 to 200 μm, more preferably 20 to 150 μm, and even more preferably 25 to 120 μm.

The protective film used in one aspect of the present invention may be a porous film having a large number of pores. The sheet having the porous film can be used as it is without removing the porous film.
The average pore diameter of the pores of the porous film is preferably 1 μm or more, more preferably 10 μm or more, still more preferably 20 μm or more, still more preferably, from the viewpoint of sufficiently exhibiting various performances of the mesoporous silica of the particles (B). Is 50 μm or more.
From the viewpoint of appropriately protecting the surface layer of the particle-containing layer, the average pore diameter of the pores of the porous film is preferably 2000 μm or less, more preferably 1000 μm or less, still more preferably 200 μm or less, still more preferably 100 μm or less. ..
That is, the average pore diameter of the pores of the porous film is preferably 1 to 2000 μm, more preferably 10 to 1000 μm, still more preferably 20 to 200 μm, and even more preferably 50 to 100 μm.

[Sheet manufacturing method]
The method for producing a sheet according to one aspect of the present invention is not particularly limited, and examples thereof include methods having the following steps (1) and (2).
-Step (1): Mesoporous silica carrying a substance containing a polymer component (A) and a platinum group element, and having a particle size D ₅₀ of 70 μm or less at an integrated value of 50% based on a volume in the particle size distribution. A step of preparing a composition for forming a particle-containing layer containing (B).
Step (2): A step of forming a particle-containing layer on at least one surface of the base material by using the composition for forming a particle-containing layer.

<Process (1)>
The step (1) is a step of preparing the above-mentioned composition for forming a particle-containing layer.
In the step (1), it is preferable to adjust the particle size distribution of the particles (B) so as to satisfy the above requirement (I) (preferably, further satisfy the above requirements (II) and (III)).
As a specific adjustment method, it is preferable that the particles of mesoporous silica are pulverized by a bead mill or the like to prepare particles having a particle size distribution satisfying the above requirements (I) to (III). By appropriately setting the bead diameter, the number of rotations, and the rotation time of the beads of the bead mill, the particles (B) having a desired particle size distribution can be easily adjusted.

The particles (B) whose particle size distribution has been adjusted in this manner are added together with the polymer component (A), and if necessary, other active ingredients are further added, and a diluting solvent such as water or ethanol is added. It is preferable to sufficiently stir to prepare the composition for forming a particle-containing layer in the form of a solution.
The solid content (active ingredient concentration) of the solution is preferably adjusted to be within the above range.

<Process (2)>
The step (2) is a step of forming a particle-containing layer on at least one surface of the base material by using the composition for forming a particle-containing layer prepared in the step (1).
The composition for forming a particle-containing layer used in one aspect of the present invention contains particles (B) having a particle size distribution satisfying the above requirement (I). Therefore, the particles (B) are easily dispersed uniformly in the composition, and the precipitation of the particles (B) is suppressed, and the particles (B) are uniformly dispersed even by application using the composition. It is possible to form an containing layer.

As a method for applying the composition for forming a particle-containing layer, in the form of a solution, for example, a spin coating method, a spray coating method, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, etc. The gravure coat method and the like can be mentioned.

The amount of the particle-containing layer-forming composition applied before drying is preferably 1 to 1500 g / m ² , more preferably 5 to 1200 g / m ² , still more preferably 10 to 1000 g / m ² , and even more preferably 15. It is ~ 900 g / m ² .

The coating film formed by applying the composition for forming a particle-containing layer on the surface of the base material can be subjected to a drying treatment to remove the diluting solvent and form the particle-containing layer.
The conditions for the drying treatment are not particularly limited, but are preferably a drying temperature of 50 to 180 ° C. (more preferably 80 to 180 ° C.) and a drying time of 0.5 minutes to 1.5 minutes.
In the particle-containing layer formed after the drying treatment, the particles (B) are unevenly distributed on the surface layer side opposite to the base material, so that a sheet capable of more effectively exhibiting various performances of mesoporous silica can be easily produced. Can be manufactured in.

In the above-mentioned direct coating method, for example, when the base material is a paper base material, a size press or the like is used on the surface of the dried paper base material in the papermaking process for producing the paper base material. A method of forming a coating film composed of a composition for forming a particle-containing layer and drying the coating film is also included.
Further, in this step, the method for forming the particle-containing layer may be a method other than directly applying the composition to the surface of the base material.

[Sheet characteristics and applications]
Unlike powder, the sheet of one aspect of the present invention can suppress contamination of other articles existing in the system, and can more effectively exhibit various performances of mesoporous silica as compared with powder. ..
In particular, in the sheet of one aspect of the present invention, particles (B) which are mesoporous silica are unevenly distributed on the surface layer side of the particle-containing layer, so that, for example, antifungal property, freshness retention property, putrefaction prevention property, and fermentation suppression. It has excellent performance improving effects such as malodor prevention and deodorant properties.
Therefore, the sheet of one aspect of the present invention is, for example, a wrapping paper for wrapping various foods, a mold-proof sheet or a freshness-preserving sheet to be sealed together with various foods in a sealed bag, a storage container for fresh foods and fruits and vegetables, and a mold-proof sheet. It can be used as a wallpaper, Japanese paper tatami mat, shoji screen, etc. It can also be used as a reaction field utilizing the catalytic function of mesoporous silica.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples. Unless otherwise specified, parts and% in each example are based on mass.
Moreover, each physical property value is a value measured by the method shown below.
(1) Particle size distribution Using a laser diffraction type particle size distribution meter (manufactured by Malvern Instruments, product name "Mastersizer 3000"), the particle size distribution of the mesoporous silica particles to be measured is measured, and the particle size distribution is measured. particle size D ₉₀ of the grain size D _10, the particle diameter D _50, and the integration of 90% by volume based on the cumulative rate of 50% by volume based on the cumulative 10% by volume based from the side the smaller particle size in Were calculated respectively.
(2) Air permeation resistance The time (seconds) required for 100 mL of air to pass through the test sheet was measured by a method based on the JIS P8117: 2009 Wang Lab test method.
(3) pH of the composition
In an environment of 23 ° C and 50% relative humidity, use a pH meter (manufactured by HORIBA Advanced Techno Co., Ltd., product name "LAQUAtwin pH-22B") to perform two-point calibration of pH 4.01 standard solution and pH 6.86 standard solution. After that, the sample was dropped and measured so as to cover the entire plane sensor.

Production Example 1 (Adjustment of particle size distribution of mesoporous silica particles)
_{Commercially available mesoporous silica carrying platinum particles (particle size D 50} = 2000 to 4000 μm at a volume-based integration rate of 50% from the smaller particle size distribution) is pulverized using a bead mill to obtain mesoporous silica. The particle size of the particles was adjusted. When adjusting the particle size, the diameter, rotation speed, and rotation time of the beads of the bead mill were appropriately set so as to obtain a predetermined particle size distribution.
The adjusted mesoporous silica particles D ₁₀ , D ₅₀ , and D ₉₀ were calculated, respectively.
Table 1 shows _{the particle size distributions (D 10} , D ₅₀ , D ₉₀ ) of mesoporous silica particles used in the following examples and comparative examples. In the particles (1) to (4), the average particle diameter of the platinum particles supported on the mesoporous silica = 2.25 nm, the pores of the mesoporous silica = the tubular shape having an average aspect ratio of 5 or more, [average of platinum particles]. Particle size / average pore diameter of mesoporous silica] <1.

As the polymer components shown in Table 2 used in the following Examples and Comparative Examples, "starch", "PVA (polyvinyl alcohol)" and "PVP (polyvinylpyrrolidone)" were used.

Examples 1-7
Particles (1), particles (2) or particles (4) were added to 100 parts by mass of the polymer components of the types shown in Table 2 in the blending amounts shown in Table 2, diluted with water, and pH = 7. , The composition for forming a particle-containing layer having a solid content concentration shown in Table 2 was prepared.
Then, the prepared composition for forming a particle-containing layer is applied on one surface of high-quality paper (thickness: 48 μm, air permeability resistance: 30 seconds) having an area of 0.01 m ^{2 as shown in Table 2.} As described above, a sheet having a particle-containing layer (hereinafter, also referred to as “test sheet”) is coated with an applicator in Example 1 and a bar coater in Examples 2 to 7 and dried at 120 ° C. for 90 seconds. Was prepared and evaluated later.
In the prepared test sheet, ^{the content of particles per 1 m 2} , the mass of the particle-containing layer after drying, the air permeability resistance of the test sheet, and the content of particles in the test sheet are as shown in Table 2. rice field.

Comparative Example 1
Water was added to the particles (1) without blending the polymer component to prepare a composition having a solid content concentration of 2.0% by mass. Then, as in Example 1, an attempt was made to apply the composition on one surface of the woodfree paper using an applicator and a bar coater, but in both cases, the particles settled in the composition. , Could not be applied and the sheet could not be prepared. Therefore, it was completed without performing the evaluation described later.

Comparative Example 2
100 parts by mass of the particles (3) were added to 100 parts by mass of PVA and diluted with water to prepare a composition having a pH of 7 and a solid content concentration of 2.1% by mass. Then, as in Example 1, the composition is applied onto one surface of woodfree paper using an applicator to prepare a sheet (test sheet) having a particle-containing layer, and the evaluation described later is performed. rice field. In the prepared test sheet, ^{the content of particles per 1 m 2} , the mass of the particle-containing layer after drying, the air permeability resistance of the test sheet, and the content of particles in the test sheet are as shown in Table 2.

Comparative Example 3
A sheet having a layer made of starch (test sheet) was prepared in the same manner as in Example 2 except that the particles of mesoporous silica were not blended, and the test described later was carried out. The mass of the layer made of starch after drying and the air permeability resistance of the test sheet are as shown in Table 2.

Comparative Example 4
The high-quality paper used in Example 1 and the like was used as a test sheet as it was, and the evaluation described later was performed.

Comparative Example 5
The particles (3) shown in Table 1 were used as they were in the same blending amount as the particle content of the test sheet prepared in Example 1, and the evaluation described later was performed.

Comparative Example 6
The evaluation described later was performed with the case where nothing was used as Comparative Example 6.

Using the test sheets prepared in Examples 1 to 7 and Comparative Examples 2 to 3, and Comparative Examples 4 to 6 were evaluated as follows under the conditions described above. These results are shown in Table 3.

[Evaluation of antifungal properties of bread]
Bread with no food additives, preservatives and colorings and an expiration date of 2 days is placed in a polyethylene bag, and test sheets are used in Examples 1 to 7 and Comparative Examples 2 to 3, and woodfree paper is used in Comparative Example 4. In Comparative Example 5, the particles (B) were put in a bag and the bag was sealed. In Comparative Example 6, only the bread was put in a bag and the bag was sealed as it was. Then, the bag containing these breads was allowed to stand in an environment of 23 ° C. and a relative humidity of 50%. After 2, 3, 5, 6, and 60 days, the surface of the bread was visually observed and the number of molds generated was counted. The evaluation of the sample in which mold was observed was completed.

[Evaluation of freshness retention of Japanese mustard spinach]
Put fresh Japanese mustard spinach in a polyethylene bag, test sheets in Examples 1 to 7, Comparative Examples 2 to 3, woodfree paper in Comparative Example 4, particles (B) in Comparative Example 5, and what in Comparative Example 6. The bags were sealed and allowed to stand in an environment of 23 ° C. and 50% relative humidity. The color of Japanese mustard spinach after 14 days was visually observed, and the freshness retention of Japanese mustard spinach was evaluated according to the following criteria, and A and B were accepted.
-A: All stems and leaves were lush and highly water-retaining.
-B: Some leaves were slightly brown, but the stems were lush and highly water-retaining.
-C: All stems and leaves were brown, but the shape was maintained.
-D: All stems and leaves turned brown, the shape was not maintained, and liquefaction was observed.

The sheets (1) to (7) produced in Examples 1 to 7 were excellent in antifungal properties and freshness retention, and the results showed that various performances of mesoporous silica were effectively exhibited.
On the other hand, when the sheet (8) produced in Comparative Example 2 and the particles (3) of Comparative Example 5 are used as they are, the particle content of Example 3 is low even though the particle content is high. The evaluation of the antifungal property is about the same as that of the sheet (3), and the result is that the freshness retention is inferior, and it can be seen that the various performances of the mesoporous silica are not sufficiently expressed. Further, in Comparative Example 3 and Comparative Example 4, the effects such as antifungal property and freshness retention were not particularly recognized.

1a, 1b, 1c, 1d sheet 11 Base material 12, 12a, 12b Particle-containing layer 13, 13a, 13b Protective film

Claims (15)

1. A sheet having a base material and a particle-containing layer.
   The particle-containing layer contains a polymer component (A) and particles (B) which are mesoporous silica carrying a substance containing a platinum group atom.
   _{A sheet in which the particle size D 50} at an integrated value of 50% based on the volume in the particle size distribution of the particles (B) is 70 μm or less.
2. The particle size _{D 90} of at integrated value of 90% by volume basis in the particle size distribution of the particles (B), the ratio _[D 90 _{/ D 50]} of the particle diameter _{D 50,} is 60.0 or less, claim 1 The sheet described in.
3. The particle size _{D 10} in the integrated value 10% by volume basis in the particle size distribution of the particles (B), wherein the ratio of the particle diameter _{D 50 [D} 10 _{/ D 50],} is 0.15 or more, according to claim 1 Or the sheet according to 2.
4. The sheet according to any one of claims 1 to 3, wherein _{the particle size D 90} having an integrated value of 90% based on the volume in the particle size distribution of the particles (B) is 300 μm or less.
5. The sheet according to any one of claims 1 to 4, wherein _{the particle size D 10} having an integrated value of 10% based on the volume in the particle size distribution of the particles (B) is 0.010 μm or more.
6. The sheet according to any one of claims 1 to 5, wherein the thickness of the base material is 1 to 1000 μm.
7. The sheet according to any one of claims 1 to 6, wherein the air permeability resistance of the sheet is more than 0 seconds.
8. The sheet according to any one of claims 1 to 7, wherein the base material contains at least a paper base material.
9. The sheet according to any one of claims 1 to 8, wherein the polymer component (A) contains a hydroxyl group-containing polymer (A1).
10. The sheet according to claim 9, wherein the hydroxyl group-containing polymer (A1) contains at least one selected from polyvinyl alcohol-based resin, phenol-based resin, and polysaccharide.
11. The sheet according to claim 10, wherein the polysaccharide contains at least one of starch and cellulose.
12. According to any one of claims 1 to 11, the content of the particles (B) is 20 to 1000 parts by mass with respect to 100 parts by mass of the total amount of the polymer component (A) contained in the particle-containing layer. The sheet of description.
13. The sheet according to any one of claims 1 to 12, wherein the content of the particles (B) per ^{1 m 2} of each particle-containing layer contained in the sheet is ^{0.10 to 20 g / m 2.}
14. _{Particle size D 50} at a volume-based integrated value of 50% in the particle size distribution of the particles (B), which contains the polymer component (A) and the particles (B) which are mesoporous silica carrying a substance containing a platinum group element. A composition for forming a particle-containing layer used for forming a particle-containing layer having a particle size of 70 μm or less.
15. A method for manufacturing a sheet, which comprises the following steps (1) and (2).
    -Step (1): Mesoporous silica carrying a substance containing a polymer component (A) and a platinum group element, and having a particle size D ₅₀ of 70 μm or less at an integrated value of 50% based on a volume in the particle size distribution. A step of preparing a composition for forming a particle-containing layer containing (B).
    Step (2): A step of forming a particle-containing layer on at least one surface of the base material by using the composition for forming a particle-containing layer.

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