Papermaking material and method for manufacturing the same

Abstract

To provide air purification performance without the application of air purification paint. [Solution] The papermaking material consists of a mixed material formed by mixing one or more types of organic fibers containing fibrillated fibers with a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon.

Description

[Technical Field]

[0001] The present invention relates to a papermaking structure and a method for manufacturing the same that removes harmful substances such as ozone and volatile organic compounds (VOCs) from the atmosphere, thereby enabling air purification. In particular, it relates to a papermaking structure and a method for manufacturing the same that have the ability to remove harmful substances such as ozone from the atmosphere without the application of an air purification coating, i.e., air purification performance. [Background technology]

[0002] Ozone in the atmosphere, specifically ozone generated in the troposphere, is produced by photochemical reactions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) due to direct sunlight, and has adverse effects on human health and terrestrial ecosystems. Therefore, with the aim of removing ozone, a harmful gas in the atmosphere, the applicant has previously developed an aqueous coating composition having ozone decomposition performance as disclosed in Patent Documents 1 to 3 (hereinafter referred to as air purification coating).

[0003] The air purification paints disclosed in Patent Documents 1 to 3 are paints containing an aqueous resin, activated carbon, and a manganese oxide-based catalyst. By applying these paints to a substrate, the activated carbon and manganese oxide-based catalyst, which have ozone removal properties, can be supported on the substrate using the aqueous resin as a binder. With such air purification paints containing activated carbon and manganese oxide-based catalysts, as described in Patent Documents 1 and 2, for example, by applying them to resin or metal vehicle parts such as electric fans and front grilles that have a large volume of air passing through them, it becomes possible to equip automobiles and other vehicles with a function to decompose ozone in the atmosphere. Furthermore, as described in Patent Document 3, by applying them to blowers such as electric fans, circulators, air conditioners, and air purifiers, it becomes possible to blow air with reduced ozone concentration. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2020-152871 [Patent Document 2] Japanese Patent Application Laid-Open No. 2023-116044 [Patent Document 3] Japanese Patent Application Laid-Open No. 2022-013546 [Summary of the Invention] [Problems to be Solved by the Invention]

[0005] Here, according to the air purification paint containing an aqueous resin, activated carbon, and a manganese oxide-based catalyst disclosed in Patent Documents 1 to 3, by applying it to a substrate, the activated carbon and the manganese oxide-based catalyst are supported on the substrate with the aqueous resin as a binder. Therefore, it is easy to use regardless of the type of substrate. However, since it is a paint, its preparation and painting are time-consuming and costly, and painting technology is also required. Therefore, in order to realize a wide variety of product lineups that greatly contribute to air purification, the development of product technologies having air purification performance without using paint is also desired.

[0006] Therefore, an object of the present invention is to provide a paper sheet having air purification performance without applying an air purification paint. [Means for Solving the Problems]

[0007] The paper sheet of the invention according to claim 1 is a mixed sheet in which at least one or two or more organic fibers are mixed with a powdery manganese oxide-based catalyst and / or powdery or fibrous activated carbon, and the organic fiber contains fibrillated fiber.

[0008] The organic fiber may be a synthetic fiber or a natural fiber, and at least fibrillated fiber is included, and it may be only fibrillated fiber or a combination of fibrillated fiber and non-fibrillated fiber. The fibrillated fibers described above are fibers that have fibrils on their surface. Fibril refers to microfibers, and fibrillation is the phenomenon where fibrils inside the fiber appear on the surface due to friction, causing fraying and splintering.

[0009] The above-mentioned mixture of organic fibers and powdered manganese oxide catalyst and / or powdered or fibrous activated carbon means a mixture of organic fibers and powdered manganese oxide catalyst, a mixture of organic fibers and powdered or fibrous activated carbon, or a mixture of organic fibers, powdered manganese oxide catalyst, and powdered or fibrous activated carbon. Here, the manganese oxide-based catalyst can be any catalyst that has a catalytic function for ozonolysis, for example, metal oxide catalysts such as manganese monoxide or manganese dioxide, but manganese dioxide-based catalysts are preferred. As the activated carbon mentioned above, for example, coconut shell activated carbon, petroleum pitch-based activated carbon, and wood-based activated carbon, which have a high specific surface area for adsorbing harmful substances such as ozone and VOCs, are preferably used, and among these, coconut shell activated carbon is more preferred. This activated carbon may be in powder form or fibrous form, or a combination of powder and fibrous forms may be used. The term "powdered" as used above refers to an aggregate of particles smaller than 1 mm, and includes the concept of granular powder.

[0010] The mixed paper body of the papermaking body according to claim 2 further includes a binder that bonds the organic fibers together. The above-mentioned binder adheres the fibers together by melting or dissolving due to heating, and may be binder fibers or cured resin products (particulate or film-like). Examples include polyester-based and polyvinyl alcohol-based binder fibers, or cured products of thermosetting resins such as phenolic resin, melamine resin, epoxy resin, and polyester resin.

[0011] The binder in the papermaking body of the invention of claim 3 is a binder fiber. The binder fibers mentioned above are preferably polyester-based binder fibers or polyvinyl alcohol-based binder fibers.

[0012] The organic fibers in the papermaking body of claim 4 further include non-fibrillated fibers.

[0013] The fibrillated fibers in the papermaking body of the invention of claim 5 are one or more of the following: fibrillated acrylic fibers, fibrillated polyamide fibers, and fibrillated cellulose fibers. The fibrillated acrylic fibers described above preferably contain hydrophilic groups. The fibrillated polyamide fiber described above is preferably an aramid fiber. The fibrillated cellulose fibers mentioned above are preferably wood pulp fibers.

[0014] The non-fibrillated fibers of the papermaking body according to claim 6 are one or more of the following: polyester fibers, polyurethane fibers, nylon fibers, polypropylene fibers, and acrylic fibers.

[0015] The papermaking material according to claim 7 preferably has a basis weight (basis weight) of 20 to 500 g / m². 2 , comfortably, 20-300g / m 2 More preferably, 50-200 g / m² 2 It falls within the range of [the specified range].

[0016] The manganese oxide-based catalyst in the papermaking body of the invention of claim 8 is a manganese dioxide-based catalyst.

[0017] The manganese oxide-based catalyst used in the papermaking body of the invention of claim 9 has an average particle size that is preferably in the range of 0.1 to 10 μm, more preferably 0.5 to 8 μm, and even more preferably 1 to 5 μm. The above average particle diameter is the median diameter measured by the laser diffraction / scattering method. The "median diameter" is, according to the definitions of the terms in the main text and commentary of JIS Z8901 "Powders and Particles for Testing", in the particle size distribution of a powder, the particle diameter (diameter) at which the number (or mass) larger than a certain particle diameter occupies 50% of that of the entire powder, that is, the particle diameter at which the oversize is 50%, and is usually referred to as the median diameter or 50% particle diameter and denoted as D 50 It is expressed as such. Definedly, the size of a particle group is expressed by the average particle diameter and the median diameter, but here, it is the value measured by the laser diffraction / scattering method for product description display. And this "median diameter measured by the laser diffraction / scattering method" means the particle diameter (D 50 ) at which the integrated weight part is 50% in the particle size distribution obtained by the laser diffraction / scattering method using a laser diffraction type particle size distribution measuring device. Note that the above numerical values are not strict, there are errors for each product, and it does not deny the mixing of errors of about 10% or less including errors due to measurement etc. From the perspective of this error, it exhibits a normal distribution, and the particle diameter shows a normal distribution, so even if the median diameter is regarded as approximately equal to the average particle diameter, the difference between the two is within a few percent and is at the level that can be regarded as an error.

[0018] The activated carbon of the paper sheet of the invention according to claim 10 preferably has a BET specific surface area in the range of 500 m 2 / g or more and 3000 m 2 / g or less, more preferably 600 m 2 / g or more and 2500 m 2 / g or less, and still more preferably 700 m 2 / g or more and 2000 m 2 / g or less. The above BET specific surface area is measured by the gas adsorption method (BET method) of N2 adsorption.

[0019] The fibrillated fiber of the paper sheet of the invention according to claim 11 preferably uses those having a CSF (Canadian Standard Freeness) value in the range of 30 to 700 ml, more preferably 200 to 600 ml, and still more preferably 300 to 500 ml. The above CSF values ​​were measured according to JIS P8121 Pulp - Determination of drainability - Part 2: “Canadian Standard” freeness method (ISO 5267-2 “Pulps - Determination of drainability - Part 2: “Canadian Standard” freeness method”).

[0020] The method for producing a paper product according to claim 12 involves wet-processing a papermaking slurry, which is obtained by mixing one or more organic fibers containing at least fibrillated fibers with a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon and a dispersion medium, and then drying it. [Effects of the Invention]

[0021] The papermaking material according to claim 1 is a mixed papermaking material comprising one or more organic fibers, including at least fibrillated fibers, and a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon. Therefore, the powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon are entangled, captured, and fixed by the fibrillated fibers, and thus possess the ability to remove harmful substances such as ozone from the atmosphere, i.e., air purification performance, without the application of air purification coatings.

[0022] According to the papermaking body of claim 2, since it further includes a binder that bonds the organic fibers together, in addition to the effects described in claim 1, it is possible to increase strength and rigidity.

[0023] According to the papermaking body of claim 3, since the binder is binder fiber, in addition to the effects described in claim 2, manganese oxide-based catalysts and activated carbon are less likely to be masked.

[0024] According to the papermaking body of claim 4, the organic fibers further include non-fibrillated fibers, and in addition to the effects described in claim 1, it is possible to increase the air permeability.

[0025] According to the papermaking body of claim 5, since the fibrillated fibers are one or more of fibrillated acrylic fibers, fibrillated polyamide fibers, and fibrillated cellulose fibers, in addition to the effects described in claim 1, it is possible to improve the scavenging ability to manganese oxide-based catalysts and activated carbon at low cost.

[0026] According to the papermaking body of claim 6, since the non-fibrillated fibers are one or more of polyurethane fibers, nylon fibers, polypropylene fibers, and acrylic fibers, in addition to the effects described in claim 4, costs can be reduced.

[0027] According to the papermaking body of the invention of claim 7, its basis weight is preferably 20 to 500 g / m². 2 , comfortably, 20-300g / m 2 More preferably, 50-200 g / m² 2 Since it is within the range, in addition to the effects described in claim 1, it can achieve both ease of handling and breathability.

[0028] According to the papermaking body of claim 8, since the manganese oxide-based catalyst is a manganese dioxide-based catalyst, it has high catalytic activity, and in addition to the effects described in claim 1, it is possible to increase the ozone decomposition efficiency.

[0029] According to the papermaking body of claim 9, the manganese oxide-based catalyst has an average particle size preferably in the range of 0.1 to 10 μm, more preferably 0.5 to 8 μm, and even more preferably 1 to 5 μm. Therefore, in addition to the effects described in claim 1, it is possible to improve the air purification efficiency relative to the amount of manganese oxide-based catalyst attached.

[0030] According to the papermaking body of the invention of claim 10, the activated carbon has a BET specific surface area of ​​preferably 500 m². 2 / g or more, 3000m 2 / g or less, more preferably 600m 2 / g or more, 2500m 2 It is less than or equal to / g, and more preferably 700m2 / g or more, 2000m 2 Since it is within the range of / g or less, in addition to the effects described in claim 1, it is possible to improve the air purification efficiency relative to the amount of activated carbon attached.

[0031] According to the papermaking body of claim 11, the fibrillated fibers have a CSF value preferably in the range of 30 to 700 ml, more preferably 200 to 600 ml, and even more preferably 300 to 500 ml. Therefore, in addition to the effects described in claim 1, the ability to capture manganese oxide-based catalysts and activated carbon can be increased, and air permeability can also be ensured.

[0032] According to the method for manufacturing a papermaking body of the invention of claim 12, a papermaking slurry is obtained by wet papermaking and drying a papermaking slurry made by mixing one or more organic fibers containing at least fibrillated fibers, a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon and a dispersion medium. As a result, the obtained papermaking body has the manganese oxide-based catalyst and / or activated carbon entangled and captured and fixed by the fibrillated fibers, and is provided with the ability to remove harmful substances such as ozone from the atmosphere, i.e., air purification performance, without the application of air purification paint. [Brief explanation of the drawing]

[0033] [Figure 1] Figure 1 is a scanning electron microscope (SEM) image (×50) of the paper machine from Example 1. [Figure 2] Figure 2 is a scanning electron microscope (SEM) image (×200) of the paper machine from Example 1. [Figure 3] Figure 3 is a scanning electron microscope (SEM) image (×400) of the paper machine from Example 1. [Figure 4] Figure 4 is a scanning electron microscope (SEM) image (×50) of the paper machine from Example 2. [Figure 5] Figure 5 is a scanning electron microscope (SEM) image (×200) of the paper machine from Example 2. [Figure 6]Figure 6 is a scanning electron microscope (SEM) image (×400) of the paper machine from Example 2. [Figure 7] Figure 7 is a scanning electron microscope (SEM) image (×50) of the paper machine from Example 3. [Figure 8] Figure 8 is a scanning electron microscope (SEM) image (×200) of the paper machine from Example 3. [Figure 9] Figure 9 is a scanning electron microscope (SEM) image (×400) of the paper machine from Example 3. [Figure 10] Figure 10 is a scanning electron microscope (SEM) image (×50) of the paper machine material from Reference Example 1. [Figure 11] Figure 11 is a scanning electron microscope (SEM) image (×200) of the paper machine material from Reference Example 1. [Figure 12] Figure 12 is a scanning electron microscope (SEM) image (×400) of the paper machine material from Reference Example 1. [Figure 13] Figure 13 is a graph showing the measurement results of the ozone decomposition rate in air purification performance tests of the paper machine from Example 4 and the nonwoven fabric coated with the air purification coating from Reference Example 1. [Modes for carrying out the invention]

[0034] [Embodiment] The following describes a papermaking body according to an embodiment of the present invention. The papermaking body of this embodiment is made by mixing one or more types of organic fibers, each containing at least fibrillated fibers, with a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon; that is, it is a mixed papermaking body of organic fibers containing fibrillated fibers and a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon.

[0035] Organic fibers are intricately intertwined and form the framework of the papermaking body, and include at least fibrillated organic fibers, i.e., fibrillated fibers. Organic fibers may be synthetic or regenerated chemical fibers, or natural fibers such as plant or animal fibers.

[0036] Preferably, the chemical fibers are synthetic fibers of thermoplastic resins, such as polyethylene (PE) fibers, polypropylene (PP) fibers, poly-1-butene fibers and other polyolefin fibers, polyester fibers such as polyethylene terephthalate (PET) fibers and polybutylene terephthalate (PBT) fibers, polylactic acid fibers, polyvinyl alcohol (PVA) fibers (vinylon fibers), nylon fibers, aramid fibers and other polyamide fibers, acrylic fibers, polyurethane fibers, polyacetal fibers, polystyrene fibers, etc.

[0037] Preferably, the natural fibers are plant fibers, such as cellulosic fibers (pulps from wood, bamboo, straw, grass, cotton, hemp, etc.). Among these, wood pulp having many hydroxyl groups (OH groups) is preferred from the viewpoint of hydrophilicity and dispersibility in water. Examples of wood pulps include chemical pulps such as unbleached hardwood kraft pulp (LUKP), bleached hardwood kraft pulp (LBKP), unbleached softwood kraft pulp (HNKP), and bleached softwood kraft pulp (NBKP); mechanical pulps such as groundwood pulp (GP), pressure-pressurized groundwood pulp (PGW), and thermomechanical pulp (TMP); and recycled paper pulps such as dainking pulp (DIP) and waste pulp (WP), as well as semi-chemical pulps (CP). However, from the viewpoint of low cost and high capture ability of manganese oxide-based catalysts and activated carbon, hardwood kraft pulp is more preferred.

[0038] The fibrils in fibrillated fibers are formed by beating and disintegrating fibers using, for example, a refiner, beater, pulper, defibration machine, or pressurized water jet (water jet punching), or by swelling with a swelling agent and then compressing them. In other words, fibrillated fibers are fibers that have numerous fibrils (fine, napped portions) formed by the random cleavage of single fibers along their main axis through beating or the like. Beating is defined as "the process of repeatedly compressing and releasing pulp by passing a pulp slurry between rotating, opposing, uneven blades of a refiner, beater, etc., causing swelling, fibrillation, and cutting of pulp fibers" (The Chemical Society of Japan, ed., "Chemical Handbook: Applied Chemistry (6th Edition)," p. 250, published January 30, 2003, by Maruzen Co., Ltd.).

[0039] Fibrillated fibers, due to the presence of fibrils, can capture manganese oxide-based catalysts and activated carbon through fibril entanglement and fix (retain) them in the fibers (between fibrils, between fibrils and the main axis of the fiber, and between fibers), and can also entangle (cross-entangle) the fibers themselves, thereby providing overall shape retention.

[0040] As for the fibrillated fiber, one type may be used alone, or two or more types may be used in combination, preferably one or more of acrylic fibers, polyamide fibers, and cellulose fibers. As fibrillated acrylic fibers, those having hydrophilic groups (hydrophilic functional groups) such as carboxyl groups are preferably used, as they allow for good dispersibility during papermaking slurry preparation, making it less likely to form clumps, and also enhance the ability to capture manganese oxide-based catalysts and activated carbon, as well as the interlocking properties of the fibers. Examples of fibrillated polyamide fibers include aromatic nylon fibers such as aramid fibers and aliphatic nylon fibers, but aramid fibers are preferred, and aramid fibers include para-aramid and meta-aramid. From the viewpoint of strength, para-aramid (poly-para-phenylene terephthalamide) is more preferred. As a fibrillated cellulose fiber, wood pulp is preferable because it is inexpensive to obtain, disperses well during papermaking slurry preparation, is less prone to clumping, and enhances the ability to capture manganese oxide catalysts and activated carbon, as well as the interlocking properties of the fibers. In particular, fibrillated cellulose fibers can enhance the bonding properties between fibers through chemical bonding by hydrogen bonds of the hydroxyl groups present in cellulose, while also ensuring breathability.

[0041] These fibrillated polyamide fibers, such as fibrillated acrylic fibers and fibrillated aramid fibers, as well as fibrillated cellulose fibers, are low-cost and can enhance the ability to capture manganese oxide catalysts and activated carbon.

[0042] Fibrillated fibers are preferably those with a CSF (Canadian Standard Freeness) value in the range of 30 to 700 ml, more preferably 200 to 600 ml, and even more preferably 300 to 500 ml. That is, it is preferable to use fibers that have been beaten or otherwise fibrillated until the CSF value is preferably in the range of 30 to 700 ml, more preferably 200 to 600 ml, and even more preferably 300 to 500 ml. Fibrillated fibers with a CSF value within the above range offer good dewatering during papermaking, enhance the capture ability of manganese oxide-based catalysts and activated carbon, improve inter-fiber entanglement, and ensure good air permeability.

[0043] The average fiber length of the fibrillated fibers is, for example, within the range of 0.1 to 6.0 mm, preferably 0.5 to 6.0 mm, more preferably 1.0 to 5.0 mm, and even more preferably 1.0 to 3.0 mm. Fibers that are too long result in reduced dispersibility, uniformity, and form, while fibers that are too short lead to increased wire leakage during papermaking, resulting in low yield and strength. When the average fiber length is within the range of preferably 0.5 to 6.0 mm, more preferably 1.0 to 5.0 mm, and even more preferably 1.0 to 3.0 mm, the papermaking properties, such as yield, form, and strength of the paper, are good.

[0044] In addition to fibrillated fibers, the organic fibers may also include non-fibrillated organic fibers. Depending on the material (type) and content of the non-fibrillated fibers, it is possible to easily control the entanglement of fibrillated fibers and the air permeability of the paper, thereby improving air permeability and form. The ratio of fibrillated fibers to non-fibrillated fibers is preferably fibrillated fibers:non-fibrillated fibers = 100:0 to 50:50, more preferably 100:0 to 60:40, and more preferably 100:100 to 70:30. As for the non-fibrillated fiber, one type may be used alone, or two or more types may be used in combination. Preferably, costs can be reduced by using one or more of the following: polyester fibers, polyurethane fibers, nylon fibers, polypropylene fibers, and acrylic fibers.

[0045] The average fiber length of non-fibrillated fibers is, for example, within the range of 0.1 to 6 mm, preferably 0.5 to 6.0 mm, more preferably 1.0 to 6.0 mm, and even more preferably 1.0 to 5.0 mm. Fibers that are too long result in reduced dispersibility, uniformity, and form, while fibers that are too short lead to increased wire leakage during papermaking, resulting in low yield and strength. When the average fiber length is preferably within the range of 0.5 to 6.0 mm, more preferably 1.0 to 6.0 mm, and even more preferably 1.0 to 5.0 mm, the papermaking properties, such as yield, form, and strength of the paper, are good.

[0046] The average fiber diameter (thickness) of non-fibrillated fibers is, for example, within the range of 1 to 500 μm, preferably 1 to 60 μm, more preferably 1 to 30 μm, and even more preferably 2 to 20 μm. If the fiber diameter is too thick, dispersibility, uniformity, and form will decrease, while if the fiber diameter is too thin, the strength will decrease. If the average fiber diameter is within the range of preferably 1 to 60 μm, more preferably 1 to 30 μm, and even more preferably 2 to 20 μm, the papermaking properties such as form and strength of the paper can be improved.

[0047] As for the organic fibers, fibrillated fibers may be used alone, or fibrillated and non-fibrillated fibers may be used in combination. Depending on the intended use of the paper and the environment in which it is used, one or more types may be appropriately selected. In this embodiment, since these organic fibers are used in wet papermaking, they are typically short fibers with a fiber length of 6.0 mm or less. The short organic fibers may be those that have been manufactured to be short in advance by controlling the raw materials and manufacturing method, or those obtained by cutting continuous long fibers, or those obtained by stirring continuous long fibers in a dispersion medium such as water with an agitator (e.g., mixer, slash finer) to shorten them. In particular, by using two or more types of organic fibers with different average fiber length, average fiber diameter, and materials, it becomes easy to control and adjust the properties of the paper, such as fiber entanglement, capture ability of activated carbon and manganese oxide-based catalysts, air permeability, density, and strength.

[0048] As manganese oxide catalysts, manganese oxides such as manganese monoxide (MnO) catalysts, manganese dioxide (manganese(IV) oxide) catalysts, and spinel-type metal manganates can be used, but manganese dioxide (MnO2) catalysts, which have high catalytic activity, are particularly preferred. Generally, manganese oxides called manganese dioxide are unstoichiometric compounds, and in reality, their composition is approximately MnOx (x=1.93~2). Manganese dioxide may be naturally occurring, manufactured by electrolysis or chemical synthesis, and may be amorphous or contain a crystalline structure. Examples of crystalline structures of manganese dioxide include alpha, beta, gamma, and delta forms, but more preferably α-manganese dioxide (cryptomelane form). Manganese dioxide may also have an amorphous structure. The manganese dioxide-based catalyst may be one in which manganese dioxide (MnO2) is used as the base and NiO, CuO, AgO, etc. are added as co-catalysts, but preferably, the manganese dioxide content is 70% or more, more preferably 80% or more.

[0049] Manganese oxide catalysts, such as manganese dioxide catalysts, have a specific surface area of ​​preferably 100 m², as measured by the gas adsorption method (BET method) for N2 adsorption. 2 / g or more, 400m 2 The specific surface area must be within the range of / g or less. If the specific surface area is too large, aggregation is likely to occur during slurry preparation, reducing dispersibility, and leading to decreased fibril capture efficiency, yield, and increased detachment. On the other hand, if the specific surface area is too small, the air purification efficiency relative to the manganese oxide catalyst content may decrease. The specific surface area of ​​the manganese oxide catalyst measured by the BET method for N2 adsorption is 100m². 2 / g or more, 400m 2 If the manganese oxide-based catalyst is within the range of / g or less, dispersibility can be improved during slurry preparation, increasing the capture efficiency, retention rate, and yield by fibrils, and enabling an improvement in air purification efficiency relative to the manganese oxide-based catalyst content (packing amount). More preferably, the specific surface area by the BET method is 150 m². 2 / g or more, 350m 2 It is less than or equal to / g, and more preferably 180m 2 / g or more, 300m 2 It is within the range of / g or less. The specific surface area of ​​manganese oxide-based catalysts obtained by the BET method is measured using the gas adsorption method (BET method) with N2 adsorption. The BET (Brunauer-Emmett-Teller) method is a method in which molecules with known adsorption occupancy areas are adsorbed onto the particle surface at the temperature of liquid nitrogen, and the specific surface area of ​​the sample is determined from the amount adsorbed. This method relies on low-temperature physical adsorption of nitrogen, an inert gas.

[0050] Manganese oxide catalysts, such as manganese dioxide catalysts, are in powder form, and their average particle size is preferably in the range of 0.1 to 10 μm, more preferably 0.5 to 8 μm, and even more preferably 1 to 5 μm. If the particle size is too large, it becomes costly, and the surface area becomes small, which may reduce the air purification efficiency relative to the manganese oxide catalyst content. On the other hand, if the particle size is too small, aggregation is likely to occur during slurry preparation, reducing dispersibility, which can lead to decreased fibril capture efficiency and yield, and increased detachment. If the average particle size of the manganese oxide catalyst is preferably in the range of 0.1 to 10 μm, more preferably 0.5 to 8 μm, and even more preferably 1 to 5 μm, dispersibility can be improved during slurry preparation, and fibril capture efficiency, yield, and retention rate can be increased, enabling an improvement in air purification efficiency relative to the manganese oxide catalyst content.

[0051] In particular, manganese oxide-based catalysts cause ozone adsorption on the catalyst, leading to a decrease in the activity energy of the ozone autodecomposition reaction, which in turn causes ozone decomposition and desorption reactions. Through this catalytic function, ozone is decomposed and converted into oxygen. Therefore, it is possible to purify and neutralize ozone.

[0052] Activated carbon can be in powder or fibrous form, and can be made from sawdust, wood chips, charcoal, bamboo charcoal, coal (lignite, brown coal, bituminous coal), petroleum-based materials (petroleum pitch, oil carbon), walnut shell charcoal, coconut shell charcoal, resins (phenolic resin, epoxy resin), rayon, etc. However, it is preferable to use coconut shell charcoal with a carbon content of 90% or more, and which has a high carbon content, such as coconut, oil palm, or sago palm. Such coconut shell charcoal has a high porosity and well-developed micropore regions, which can increase the adsorption efficiency of harmful substances such as ozone and volatile organic compounds (VOCs), and also makes it difficult for adsorbed substances to desorb.

[0053] Activated carbon such as coconut shell charcoal has a specific surface area of ​​preferably 500 m², as measured by the gas adsorption method (BET method) for N2 adsorption. 2 / g or more, 3000m 2The range is less than or equal to / g. If the specific surface area is too large, aggregation is likely to occur during slurry preparation, reducing dispersibility, and leading to decreased fibril capture efficiency, yield, and increased detachment. On the other hand, if the specific surface area is too small, the air purification efficiency relative to the activated carbon content may decrease. The specific surface area of ​​activated carbon measured by the BET method for N2 adsorption is 500m². 2 / g or more, 3000m 2 If the activated carbon is within the range of / g or less, it can be dispersed well during slurry preparation, increasing the capture efficiency, retention rate, and yield by fibrils, and enabling an improvement in air purification efficiency relative to the activated carbon content. More preferably, the specific surface area by the BET method is 600 m². 2 / g or more, 2500m 2 It is less than or equal to / g, and more preferably 700m 2 / g or more, 2000m 2 It is within the range of / g or less. Furthermore, the specific surface area of ​​activated carbon using the BET method is also measured using the gas adsorption method (BET method) for N2 adsorption.

[0054] If using powdered activated carbon, it is preferable to use one with an average particle size (median diameter measured by laser diffraction / scattering) in the range of 10 to 50 μm, more preferably 12 to 40 μm, and even more preferably 15 to 35 μm. Furthermore, if fibrous activated carbon (activated carbon fibers) is used, the fiber diameter is preferably in the range of 1 to 50 μm, more preferably 5 to 40 μm, and even more preferably 10 to 20 μm. Since wet papermaking is performed, in the case of fibrous activated carbon (activated carbon fibers), short fibers with a fiber length of 6.0 mm or less are usually used, preferably in the range of 1.0 to 6.0 mm. If the particle or fiber diameter is too large, it becomes costly, and the reduced surface area may decrease the air purification efficiency relative to the activated carbon content. On the other hand, if the particle or fiber diameter is too small, aggregation is likely to occur during slurry preparation, reducing dispersibility, and leading to decreased fibril capture efficiency, yield, and increased detachment. If the particles or fibers are within the above range, dispersibility can be improved during slurry preparation, and fibril capture efficiency, retention rate, and yield can be increased, enabling improved air purification efficiency relative to the activated carbon content.

[0055] Activated carbon adsorbs harmful substances such as ozone and VOCs into its pores. In particular, ozone adsorbed on activated carbon is converted into carbon monoxide, carbon dioxide, reactive oxygen species, oxygen, etc., by reacting with the activated carbon or by receiving electrons from the activated carbon (a catalytic function that reduces the activity energy of the ozone self-decomposition reaction). Therefore, activated carbon can purify and neutralize ozone. Furthermore, while manganese dioxide exhibits the highest catalytic activity at relatively high temperatures, activated carbon maintains high activity over a wide temperature range, including room temperature (15-25°C), and even in high humidity environments.

[0056] Preferably, using a manganese oxide-based catalyst and activated carbon in combination can reduce costs and provide a synergistic effect on ozone decomposition. Specifically, the heat of reaction between activated carbon and ozone promotes the ozone catalytic reaction of the manganese oxide-based catalyst, allows for ozone decomposition performance over a wide temperature range, allows the manganese oxide-based catalyst to enter the pores of the activated carbon, enabling efficient contact between the activated carbon and the manganese oxide-based catalyst with ozone, and prevents oxidation and consumption of the activated carbon by reactive oxygen species, etc. As a result, it is expected that the ozone removal efficiency will be higher compared to using only one of the manganese oxide-based catalyst or activated carbon. The content ratio of manganese oxide-based catalyst to activated carbon is preferably 10 / 90 ≤ manganese oxide-based catalyst / activated carbon ≤ 90 / 10, more preferably 20 / 80 ≤ manganese oxide-based catalyst / activated carbon ≤ 80 / 20, and even more preferably 30 / 70 ≤ manganese oxide-based catalyst / activated carbon ≤ 70 / 30.

[0057] The content (loading amount) of manganese oxide-based catalyst and / or activated carbon in the papermaking body is preferably in the range of 10 to 50% by mass, more preferably 12 to 45% by mass, and even more preferably 15 to 40% by mass, based on 100% by mass of the entire papermaking body. Within that range, good air permeability of the papermaking material can be ensured, making it possible to improve air purification efficiency.

[0058] Furthermore, the papermaking body of this embodiment may also include a binder that bonds the organic fibers together. A binder is a cured resin product in which some or all of the particles of a thermosetting resin, such as binder fibers, phenolic resin, melamine resin, epoxy resin, or polyester resin, have melted.

[0059] Binder fibers are made by forming polymers that partially or completely melt or partially dissolve when heated into fibers (shaping them into fibers). Any material that can melt or dissolve when heated to bond the fibers together is acceptable, and heat-meltable binder fibers or easily soluble binder fibers are used.

[0060] The heat-meltable binder fibers are made by mixing organic fibers with a manganese oxide-based catalyst and / or activated carbon. The binder component melts when dried after papermaking, meaning it melts (fluidizes) at a temperature lower than the melting or decomposition point of the organic fibers being bonded, thereby bonding the organic fibers together. The polymer of the binder component of the heat-meltable binder fiber is preferably a thermoplastic resin, and may be either an amorphous or crystalline polymer, but preferably a crystalline polymer is used to obtain high adhesion. Examples of such materials include polyester, polyolefin, and polyamide (nylon). Heat-meltable binder fibers include a fully melted type made of a single polymer (e.g., fully melted polyester type), a core-sheath type made of a composite fiber of a core component (high melting point component) and a sheath component (low melting point component) (e.g., a core and sheath component made of polyester, or a core component made of polyester such as PET and a sheath component made of polyolefin or copolymer polyester such as PE or PP), and a side-by-side type in which two components are bonded together, and any of these may be used. Preferably, by using a core-sheath fiber, low-temperature bonding is possible, so an energy saving effect can be expected, and the presence of the core can also increase strength. More preferably, a core-sheath type polyester binder fiber is used.

[0061] When easily soluble binder fibers are mixed with organic fibers, a manganese oxide-based catalyst and / or activated carbon, and a dispersion medium, they swell due to the moisture in the papermaking slurry, and partially dissolve due to the heat during drying after papermaking (at a temperature higher than the water dissolution temperature of the binder fibers), thereby bonding the organic fibers together. Polyvinyl alcohol-based binder fibers having hydrophilic groups such as hydroxyl groups are preferred as easily soluble binder fibers.

[0062] For example, a papermaking slurry containing fibrillated organic fibers, a manganese oxide-based catalyst and / or activated carbon, a dispersion medium, and binder fibers or binder particles (for example, mixed in the form of a thermosetting resin binder solution) is wet-processed and then dried. During the drying process, the heating temperature causes all or part of the binder fibers or binder particles to melt or dissolve, and the binder components of these binder fibers or particles adhere to the organic fibers.

[0063] In other words, the binders that bond organic fibers together include fibrous materials derived from core-sheath type or side-by-side type heat-meltable binder fibers or easily soluble binder fibers, which are made by mixing organic fibers with a manganese oxide-based catalyst and / or activated carbon; and particulate or film-like materials (cured resin products) derived from fully melted type heat-meltable binder fibers, which are made by mixing organic fibers with a manganese oxide-based catalyst and / or activated carbon; or from thermosetting resin particles, which are made by mixing organic fibers with a manganese oxide-based catalyst and / or activated carbon.

[0064] Preferably, if the binder bonding the organic fibers is a core-sheath type heat-meltable binder fiber and / or easily soluble binder fiber, it is easier to bond only the entanglement points (fiber contact points) of the organic fibers, making it difficult to mask manganese oxide-based catalysts or activated carbon, and also making it difficult to block the voids between fibers, thus ensuring breathability. Furthermore, the presence of a binder fiber core improves the strength of the paper, making it less prone to sagging and creating a soft texture. In particular, if binder fibers are used, no binder solution is used, saving energy that would otherwise be required to evaporate the water, and eliminating the need for wastewater treatment of the solution, thus avoiding contamination of the work environment. By including a binder that adheres these organic fibers together, it is possible to improve the strength, rigidity, and shape retention (moldability) of the papermaking material.

[0065] The basis weight (basis weight) of the paper produced in this embodiment is preferably 20 to 500 g / m². 2 , comfortably, 20-300g / m 2 More preferably, 50-200 g / m² 2 It falls within that range. Within that range, handling can be improved, and ventilation can be ensured to enhance air purification efficiency. The air permeability of the papermaking body in this embodiment is preferably in the range of 100 to 10,000 μm / Pa·s, more preferably in the range of 200 to 8,000 μm / Pa·s, and even more preferably in the range of 400 to 5,000 μm / Pa·s. Within this range, it is possible to achieve both the strength of the papermaking body and the efficiency of air purification through air permeability. For the air permeability in this case, the paper machine was set up in the test apparatus so that one side of the 50φ punched paper machine was a pressure chamber in the thickness direction and the other side in the thickness direction was an open chamber. Nitrogen gas (flow controller (PAC-D2): Horiba Stec Co., Ltd.) was supplied at 0.5 L / min, 0.7 L / min, and 0.9 L / min under a load of 1260 N (surface pressure 1.8 MPa) (load measuring instrument (WGA-710B): Kyowa Sangyo Co., Ltd.) in the pressure chamber on one side of the paper machine's thickness direction. The differential pressure between the open chamber and the pressure chamber (differential pressure gauge (GPG-204C11): Okano Seisakusho Co., Ltd.) was measured, and the gas air permeability (normal air permeability) was calculated from the slope of the differential pressure.

[0066] Here, the manufacturing method of the papermaking body according to this embodiment will be described in detail. In this embodiment, first, a slurry preparation step is carried out in which a papermaking slurry is prepared by mixing at least one or more types of organic fibers, including fibrillated fibers, a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon, and a dispersion medium (papermaking medium). At this time, if binder fibers or binder particles are used as a binder to bond the organic fibers together, the binder fibers or binder particles are also mixed into the papermaking slurry.

[0067] In the slurry preparation step, at least organic fibers and a manganese oxide-based catalyst and / or activated carbon are added to the dispersion medium and stirred and mixed to obtain a papermaking slurry in which at least organic fibers and a manganese oxide-based catalyst and / or activated carbon are dispersed in the dispersion medium. Water is generally used as the dispersion medium in wet papermaking, but depending on the type of organic fiber, organic solvents such as toluene, xylene, cyclohexane, and alcohols may also be used. The method of stirring and mixing to disperse the papermaking components (organic fibers, manganese oxide-based catalyst, activated carbon, binder fibers / binder particles) is not particularly limited. For example, the papermaking components can be mixed and dispersed in the dispersion medium using a rotary device such as a pulper. The fibers added to the dispersion medium may be made into a slurry using a disintegrator (as a pulp slurry), and this slurry may be mixed with the manganese oxide-based catalyst and / or activated carbon. Furthermore, the concentration of solids in the papermaking slurry (organic fibers, manganese oxide-based catalyst, activated carbon, binder fibers / binder particles) is preferably in the range of 0.5 to 2.0% in the chest and preferably in the range of 0.05 to 0.2% during papermaking. Within this concentration range, papermaking properties and the dispersibility of papermaking components can be improved, and aggregation of papermaking components can be suppressed.

[0068] Next, a papermaking process is carried out in which the papermaking slurry obtained in the slurry preparation process is used to make paper using a papermaking machine. The paper machines used in this context are not particularly limited, as long screen machines are applicable to general papermaking techniques. Examples include long screen machines, short screen machines, cylinder screen machines, inclined screen machines, twin-wire screen machines, and combination machines that combine these types of machines. In this papermaking process, a papermaking slurry, which is a mixture of organic fibers containing fibrillated fibers, a manganese oxide-based catalyst and / or activated carbon, a dispersion medium, and binder fibers or binder particles as needed, is formed using a mesh. That is, the mesh separates the liquid component (dispersion medium) from the solid component (organic fibers, manganese oxide-based catalyst, activated carbon, binder fibers / binder particles), and the solid component is aggregated (accumulated, deposited) in a mesh-like structure to obtain a wet web (wet papermaking body).

[0069] After papermaking, a drying process is carried out in which the wet web, which is an aggregate of solid components on the mesh, is squeezed as appropriate (dewatered or squeezed by reduced pressure suction, etc.) and then dried. Drying methods at this time include non-contact methods using equipment such as hot air dryers that circulate and supply hot air, atmosphere furnaces using high-temperature heaters, IR furnaces using infrared heaters, and microwave furnaces using microwaves, as well as contact methods in which the paper is dried by contact with heated rolls or hot plates. Specifically, there are drying methods using Yankee dryers, rotary (multi-cylinder) dryers, hand dryers, air dryers, cylinder dryers, suction drum dryers, and infrared dryers. In particular, non-contact methods such as blowing hot air with a hot air dryer are easy to operate and maintain, and can prevent the loss of papermaking components due to contact with the heat source.

[0070] The drying temperature should be any temperature that can evaporate the solvent and moisture contained in the wet web, for example, 100°C to 300°C, preferably 100°C to 150°C. When the papermaking components include binder fibers or binder particles (binders made of thermosetting resin particles such as phenol), the heating during drying causes some or all of the binder fibers or binder particles to melt or partially dissolve, thus bonding the fibers together. However, if the drying time is too long, a large drying oven is required for continuous drying, which increases costs and reduces productivity. Therefore, the drying time is set to, for example, 1 to 30 minutes, more preferably 1 to 20 minutes.

[0071] When implementing the present invention, if necessary, a press process may be performed on the wet web (wet paper body) before drying, or on the paper body after drying, by applying pressure in the thickness direction. Methods of pressurization at this time include, for example, applying flat plates (rigid plates) to both sides of the paper body in the thickness direction and applying hot press in the thickness direction, or using a continuous roll press or a continuous belt press. It can be either cold press or hot press. By performing this type of press processing (heat and pressure molding), the degree of contact between the organic fibers that make up the paper is increased, which can increase strength, improve the retention of manganese oxide-based catalysts and activated carbon, enhance smoothness, and adjust air permeability, density, and thickness. The final sheet-like paper mass has a thickness of, for example, 0.2 to 1.0 mm. Within this range, it is tear-resistant and can also be wound into a roll. Because it is in sheet form, processes such as rolling and pleating are also possible.

[0072] This type of wet papermaking can be carried out continuously or in batches, but continuous papermaking is preferred because it allows for higher productivity. Continuously produced paper can be handled as a roll, undergo secondary processing (cutting, etc.), and be supplied in various product forms.

[0073] In this way, a sheet-like papermaking body is obtained by wet-processing a papermaking slurry, which is a mixture of organic fibers containing fibrillated fibers, a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon, and a dispersion medium, and then drying it. In other words, the papermaking body of this embodiment is manufactured by a wet papermaking method and is a mixture of at least one or more organic fibers containing fibrillated fibers and a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon.

[0074] The papermaking material of this embodiment is a porous fiber aggregate in which organic fibers are intertwined by fibril entanglement, and manganese oxide-based catalysts and / or activated carbon are captured and fixed to the organic fibers by fibril entanglement. Therefore, the papermaking body of this embodiment has the ability to decompose and remove harmful substances such as ozone and volatile organic compounds (VOCs) from the atmosphere by manganese oxide-based catalysts and / or activated carbon fixed to the organic fibers by fibrils, thereby purifying the atmosphere (air purification performance).

[0075] In other words, the papermaking body of this embodiment contains fibrillated fibers as organic fibers, and the entanglement of the fibrils captures and / or fixes powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon to the organic fibers. Furthermore, the entanglement of the fibers by the fibrils provides shape retention (moldability). Therefore, instead of applying an air purification coating containing manganese oxide-based catalysts, activated carbon, or resin (binder), the mixture of organic fibers containing fibrillated fibers and manganese oxide-based catalysts and / or activated carbon captures the manganese oxide-based catalysts and / or activated carbon through fibril entanglement, fixing them to the organic fibers, thereby providing air purification performance that removes harmful substances such as ozone and VOCs using the manganese oxide-based catalysts and / or activated carbon.

[0076] In particular, when manganese oxide-based catalysts and / or activated carbon are supported on the fiber surface of a nonwoven fabric substrate by applying an air purification coating containing a resin (binder) and a manganese oxide-based catalyst and / or activated carbon, the manganese oxide-based catalyst and / or activated carbon are easily masked (coated) by the resin in the coating. In contrast, when the manganese oxide-based catalyst and / or activated carbon are captured by fibrilized organic fibers and fixed to the fiber surface through fibril entanglement, the manganese oxide-based catalyst and / or activated carbon are less likely to be masked, thereby suppressing the decrease in the air contact efficiency and activity of the manganese oxide-based catalyst and activated carbon due to masking, and the decrease in the removal performance of harmful substances such as ozone and VOCs (air purification performance). In other words, instead of supporting the manganese oxide catalyst and / or activated carbon on the fiber surface with a resin (binder), the manganese oxide catalyst and / or activated carbon are captured and fixed to the fiber surface by the entanglement of fibrils. Therefore, it is possible to suppress the decrease in the efficiency and activity of the manganese oxide catalyst and / or activated carbon in contact with the atmosphere due to masking by the resin, as well as the decrease in the removal performance of harmful substances such as ozone and VOCs (air purification performance).

[0077] In addition, when an air purification coating containing resin, a manganese oxide-based catalyst, and / or activated carbon is applied to a nonwoven fabric substrate, the manganese oxide-based catalyst and / or activated carbon are distributed on the surface side of the nonwoven fabric substrate, resulting in a small effective surface area for the manganese oxide-based catalyst and / or activated carbon to exhibit their air purification performance. In contrast, the papermaking body of this embodiment is a mixed material of organic fibers containing fibrillated fibers and powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon. As a result, the manganese oxide-based catalyst and / or activated carbon are distributed not only on the surface of the papermaking body but also inside. Therefore, it is possible to increase the effective surface area (air contact efficiency) in which the manganese oxide-based catalyst and / or activated carbon exhibit their air purification performance. Furthermore, the papermaking body of this embodiment has a framework of organic fibers and is porous with interconnected voids. Therefore, according to the papermaking body of this embodiment, as air passes through its voids, that is, through ventilation, the manganese oxide-based catalyst and activated carbon distributed on the surface and interior sides of the papermaking body can purify the air, thereby improving the efficiency of air purification.

[0078] In other words, if organic fibers containing fibrillated fibers are mixed with a manganese oxide-based catalyst and / or activated carbon, the manganese oxide-based catalyst and / or activated carbon will be distributed not only on the surface of the paper but also inside, making it possible to distribute the manganese oxide-based catalyst and / or activated carbon almost uniformly in the thickness direction. Therefore, as air passes through the interconnected voids between the fibers of the porous paper, harmful substances such as ozone and VOCs contained in the passing air can be decomposed and removed by the action of the manganese oxide-based catalyst and activated carbon distributed on the surface and inside of the paper.

[0079] Furthermore, when a manganese oxide-based catalyst and / or activated carbon is supported on a nonwoven fabric substrate by applying an air purification coating containing a resin (binder) and a manganese oxide-based catalyst and / or activated carbon, a large amount of resin component is required to ensure adhesion of the manganese oxide-based catalyst and activated carbon to the nonwoven fabric substrate. Moreover, considering the dispersibility of the coating, the amount of manganese oxide-based catalyst and activated carbon that can be added cannot be increased, thus limiting the amount that can be supported on the nonwoven fabric substrate. In other words, it is difficult to increase the adhesion rate of manganese oxide-based catalyst and activated carbon particles that are attached to the nonwoven fabric substrate by coating. In contrast, if organic fibers containing fibrillated fibers are mixed with a manganese oxide-based catalyst and / or activated carbon, it becomes possible to increase the amount of manganese oxide-based catalyst and / or activated carbon that can be fixed to the fibers.

[0080] Furthermore, if organic fibers containing fibrillated fibers are mixed with a manganese oxide-based catalyst and / or activated carbon, compared to the method of imparting air purification performance by applying an air purification coating containing resin, manganese oxide-based catalyst and / or activated carbon to a nonwoven fabric substrate, the effort of preparing and applying an air purification coating containing resin, manganese oxide-based catalyst and / or activated carbon, etc., is eliminated, costs are reduced, and painting technology is not required. Therefore, productivity can be increased and costs can be reduced. Moreover, when organic fibers containing fibrillated fibers and manganese oxide-based catalyst and / or activated carbon are made together in the papermaking process, a sheet with air purification performance can be easily formed, and the thickness, basis weight, density, and air permeability (fineness of the mesh) of the paper can be easily adjusted.

[0081] Furthermore, when a papermaking slurry is made by wet-processing a mixture of organic fibers containing fibrillated fibers, a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon, a dispersion medium, and binder fibers or binder particles, and then drying it, the fibers are bonded together by the binder. When a binder is included in a papermaking body that is a mixture of organic fibers containing fibrillated fibers and a manganese oxide-based catalyst and / or activated carbon, it is possible to increase the strength, rigidity, and durability of the papermaking body.

[0082] Next, the papermaking body of this embodiment will be described with reference to an example. The papermaking material of Example 1 is a mixed material of low-fibrillated acrylic fiber A, high-fibrillated acrylic fiber B, and fibrillated cellulose fiber C as organic fibers, and a powdered α-type manganese dioxide catalyst as a manganese oxide catalyst.

[0083] In Example 1, first, 17.5 parts by mass of low-fibrillated acrylic fiber A (non-meltable pulp containing hydrophilic groups with low-beaten fibrils, average fiber length: 3 mm, CSF value: 550 mL), 2.5 parts by mass of high-fibrillated acrylic fiber B (non-meltable pulp containing hydrophilic groups with high-beaten fibrils, average fiber length: 3 mm, CSF value: 30), 20.0 parts by mass of fibrillated cellulose fiber C (LBKP, fiber length: 3 mm), and 10.0 parts by mass of manganese dioxide catalyst (manganese dioxide content: 70% or more, average particle size: 2 μm) were mixed and dispersed in water as a dispersion medium to obtain a papermaking slurry. At this time, all fibers were mixed in a slurry form (as a pulp slurry) using a disintegrator. Next, a papermaking machine was used to make papermaking slurry, which was then dried at 120°C to obtain a paper product. The paper product of this Example 1 had a basis weight of 53.9 g / m². 2 The thickness is 253 μm, and the density is 0.213 g / cm³. 3 The air permeability measured using the above-described method was 194 μm / Pa·S.

[0084] The papermaking material of Example 2 is a mixed material of organic fibers, namely low-fibrillated acrylic fiber A (same as in Example 1), high-fibrillated acrylic fiber B (same as in Example 1), and fibrillated cellulose fiber C (same as in Example 1), and powdered activated carbon (coconut shell raw material).

[0085] In Example 2, first, 17.5 parts by mass of low-fibrillated acrylic fiber A, 2.5 parts by mass of high-fibrillated acrylic fiber B, and 20.0 parts by mass of fibrillated cellulose fiber C were used as organic fibers, and activated carbon (coconut shell, average particle size: 30 μm, BET specific surface area: 1250 m²) was used. 2 10.0 parts by mass of ( / g) was mixed and dispersed in water as a dispersion medium to obtain a papermaking slurry. At this time, all fibers were mixed in a slurry form (as a pulp slurry) using a disintegrator. Next, the papermaking slurry was made using a cylinder papermaking machine, and then dried at 120°C to obtain a papermaking body. The papermaking body of this Example 2 had a basis weight of 52.5 g / m². 2 The thickness is 247 μm, and the density is 0.212 g / cm³. 3 The air permeability was 201 μm / Pa·S.

[0086] The papermaking material of Example 3 is a mixed material of organic fibers, namely low-fibrillated acrylic fiber A (same as in Examples 1 and 2), high-fibrillated acrylic fiber B (same as in Examples 1 and 2), and fibrillated cellulose fiber C (same as in Examples 1 and 2), and a manganese oxide-based catalyst, namely powdered α-type manganese dioxide catalyst (same as in Example 1) and powdered activated carbon (same as in Example 2).

[0087] In Example 3, first, 17.5 parts by mass of fibrillated acrylic fiber A, 2.5 parts by mass of fibrillated acrylic fiber B, and 20.0 parts by mass of fibrillated cellulose fiber C were mixed and dispersed in water as a dispersion medium to obtain a papermaking slurry. At this time, all fibers were mixed in a slurry form (as a pulp slurry) using a disintegrator. Next, the papermaking slurry was made using a cylinder papermaking machine, and then dried at 120°C to obtain a papermaking body. The papermaking body of this Example 3 had a basis weight of 54.7 g / m². 2 The thickness is 222 μm, and the density is 0.246 g / cm³. 3 The air permeability was 423 μm / Pa·S.

[0088] The papermaking material of Example 4 is a mixed material of organic fibers, namely low-fibrillated acrylic fiber A (same as in Examples 1-3) and non-fibrillated polyester fiber D, polyester binder fiber E as a binder, powdered α-type manganese dioxide catalyst (same as in Examples 1 and 3), and powdered activated carbon (same as in Examples 2 and 3).

[0089] In Example 4, first, 40.0 parts by mass of low-fibrillated acrylic fiber A and 30.0 parts by mass of non-fibrillated polyester fiber D (fiber length: 5 mm, fiber diameter: 13 μm) were mixed and dispersed in water as a dispersion medium to obtain a papermaking slurry. These mixtures consisted of 40.0 parts by mass of low-fibrillated acrylic fiber A, 30.0 parts by mass of non-fibrillated polyester fiber D (fiber length: 5 mm, fiber diameter: 13 μm) as organic fibers, 10.0 parts by mass of polyester binder fiber E (core: polyethylene terephthalate, sheath: crystalline copolyester core-sheath composite type, fiber length: 5 mm, fiber diameter: 13 μm) as a binder, 14.0 parts by mass of manganese dioxide catalyst as a manganese oxide catalyst, and 6.0 parts by mass of activated carbon. At this time, all fibers were mixed in a slurry form (as a pulp slurry) using a disintegrator. Next, the papermaking slurry was made using a cylinder papermaking machine, and then dried at 120°C to obtain a papermaking body. The basis weight of the papermaking body of Example 4 was 49.9 g / m². 2 The thickness is 268 μm, and the density is 0.186 g / cm³. 3The air permeability was 4497 ​​μm / Pa·S. In Example 4, the air permeability was higher than in Example 3 because the content of low-fibrillated acrylic fiber A, which has a high CSF value (water filtration efficiency), was increased.

[0090] The papermaking material of Example 5 is a mixed material comprising low-fibrillated acrylic fiber A (same as Examples 1-4) and non-fibrillated polyester fiber D (same as Example 4) as organic fibers, polyester binder fiber E (same as Example 4) as a binder, powdered α-type manganese dioxide catalyst (same as Examples 1, 3, and 4) as a manganese oxide catalyst, and powdered activated carbon (same as Examples 2, 3, and 4).

[0091] In Example 5, first, 35.0 parts by mass of low-fibrillated acrylic fiber A and 25.0 parts by mass of non-fibrillated polyester fiber D were mixed and dispersed in water as a dispersion medium to obtain a papermaking slurry. At this time, all fibers were mixed in a slurry form (as a pulp slurry) using a disintegrator. Next, the papermaking slurry was made using a cylinder papermaking machine, and then dried at 120°C to obtain a papermaking body. The papermaking body of Example 5 had a basis weight of 54.2 g / m². 2 The thickness is 283 μm, and the density is 0.191 g / cm³. 3 The air permeability was 3293 μm / Pa·S. In Example 5, the content of low-fibrillated acrylic fiber A, which has a high CSF value (water permeability), was increased, and further, the amount of manganese dioxide catalyst and activated carbon was increased, resulting in higher air permeability than Example 3 and a higher basis weight than Example 4.

[0092] In addition, as Comparative Example 1 (blank), a paper machine was prepared that contained only organic fibers and did not contain manganese oxide-based catalysts or activated carbon. Specifically, in Comparative Example 1, a paper machine was prepared using low-fibrillated acrylic fiber A (same as Examples 1-5), high-fibrillated acrylic fiber B (same as Examples 1-43), and fibrillated cellulose fiber C (same as Examples 1-3) as organic fibers.

[0093] In Comparative Example 1, first, 17.5 parts by mass of high-fibrillated acrylic fiber A, 2.5 parts by mass of low-fibrillated acrylic fiber B, and 20.0 parts by mass of fibrillated cellulose fiber C were mixed and dispersed (disintegrated and dispersed) in water as a dispersion medium to obtain a papermaking slurry. At this time, all fibers were mixed in a slurry form (as a pulp slurry) using a disintegrator. Next, the papermaking slurry was made using a cylinder papermaking machine, and then dried at 120°C to obtain a papermaking body. The papermaking body of Comparative Example 1 had a basis weight of 44.0 g / m². 2 The thickness is 184 μm, and the density is 0.239 g / cm³. 3 The air permeability was 181 μm / Pa·S. Table 1 summarizes the composition of the papermaking components for Examples 1 to 5 and Comparative Example 1. The units of the values ​​in Table 1 are parts by mass.

[0094] [Table 1]

[0095] Furthermore, as Reference Example 1, an air purification coating was prepared by applying (coating) an air purification coating to a polyester (PEs) nonwoven fabric. This coating contained 53 parts by mass of the same manganese dioxide-based catalyst as in the above example, 22 parts by mass of the same activated carbon as in the above example, 18 parts by mass of a water-based resin (polypropylene resin), 7 parts by mass of an acrylic resin, and a small amount of dispersant (5 parts by mass or less) in an aqueous solvent. This coating then produced a polyester nonwoven fabric containing the manganese dioxide-based catalyst, activated carbon, polypropylene resin, and acrylic resin. The basis weight of this Reference Example 1 nonwoven fabric was 54.3 g / m². 2 The thickness is 1000 μm and the density is 0.049 g / cm³. 3The air permeability was 8096 μm / Pa·S.

[0096] Here, Figures 1 to 12 show images of the surfaces of the paper machines from Examples 1 to 3, and the nonwoven fabric coated with the air purification coating from Reference Example 1, as observed using a scanning electron microscope (SEM). As shown in Figures 1 to 3, in the paper made of Example 1, which is a mixed material of organic fibers, specifically low-fibrillated acrylic fiber A, high-fibrillated acrylic fiber B, and fibrillated cellulose fiber C, and a powdered manganese dioxide catalyst, it can be seen that the organic fibers form the framework of the paper made, the fibers are intertwined by the fibrils, and the manganese dioxide catalyst is entangled and fixed to the fibers by the fibrils. In particular, it can be seen that the manganese dioxide catalyst in the paper made of Example 1 is significantly exposed on the surface of the organic fibers. Thus, in the papermaking body of Example 1, the manganese dioxide-based catalyst, despite having a higher specific gravity and smaller particle size than activated carbon, is captured by the fibrils and fixed to the fiber surface by the use of fibrillated acrylic fibers that have been beaten to CSF ​​30-550 ml.

[0097] Furthermore, as shown in Figures 4 to 6, in the paper made of Example 2, which is a mixed material of high-fibrillated acrylic fiber A, low-fibrillated acrylic fiber B, and fibrillated cellulose fiber C as organic fibers, and powdered activated carbon, it can be seen that the organic fibers form the framework of the paper made, the fibers are intertwined with each other by fibrils, and the activated carbon is entangled and captured by the fibrils and fixed to the fibers. In particular, it can be seen that the activated carbon in the paper made of Example 2 is also significantly exposed on the surface of the organic fibers. Thus, in the papermaking of Example 2, the use of fibrillated acrylic fibers beaten to CSF ​​30-550 ml allows activated carbon to be captured by the fibrils and fixed to the fiber surface.

[0098] Furthermore, as shown in Figures 7 to 9, in the paper made of Example 3, which is a mixed material of low-fibrillated acrylic fiber A, high-fibrillated acrylic fiber B, and fibrillated cellulose fiber C as organic fibers, and powdered manganese dioxide catalyst and powdered activated carbon as manganese oxide catalysts, the organic fibers are intertwined with each other, the organic fibers form the framework of the paper made, the fibers are intertwined by fibrils, and the manganese dioxide catalyst and activated carbon are entangled and fixed to the fibers by the fibrils. In particular, it can be seen that the manganese dioxide catalyst and activated carbon in the paper made of Example 3 are significantly exposed on the surface of the organic fibers. Thus, in the papermaking of Example 3, the use of fibrillated acrylic fibers beaten to CSF ​​30-550 ml allowed both the manganese dioxide catalyst and activated carbon to be captured by the fibrils and fixed to the fiber surface.

[0099] On the other hand, as shown in Figures 10 to 12, in the nonwoven fabric of Reference Example 1, which was prepared by coating a polyester (PEs) nonwoven fabric with an air purification paint containing powdered manganese dioxide catalyst, powdered activated carbon, aqueous resin, and a dispersant, the manganese dioxide catalyst and activated carbon are attached to the fibers by the resin (binder), and it can be seen that the manganese dioxide catalyst and activated carbon are not significantly exposed on the surface of the fibers, and are masked by the resin on the surface of the fibers.

[0100] In other words, when an air purification coating containing a manganese dioxide-based catalyst, activated carbon, aqueous resin, and dispersant is applied to a polyester (PEs) nonwoven fabric, the manganese dioxide-based catalyst and activated carbon adhere to the fiber surface of the nonwoven fabric via the resin binder and are masked by the resin. In contrast, in a paper made by mixing organic fibers containing fibrillated fibers with powdered manganese dioxide-based catalyst and / or powdered activated carbon, the manganese dioxide-based catalyst and activated carbon are exposed and fixed to the fiber surface due to fibril entanglement. Compared to Reference Example 1, in which the manganese dioxide-based catalyst and activated carbon are supported on the fibers via a resin (binder) by coating, the paper made in this embodiment has the manganese dioxide-based catalyst and activated carbon fixed to the fiber surface due to fibril entanglement. The state of fixation (support and retention) of the manganese dioxide-based catalyst and activated carbon on the fibers is clearly different between Reference Example 1 and this embodiment, allowing the two to be distinguished. Furthermore, in the papermaking body of this embodiment, since the manganese dioxide-based catalyst and activated carbon are fixed to the fiber surface by fibril entanglement, it is presumed that the manganese dioxide-based catalyst and activated carbon particles are less likely to be masked, thus allowing the air purification performance of the manganese dioxide-based catalyst and activated carbon to be efficiently expressed.

[0101] Furthermore, air purification performance tests were conducted on the paper machine material of Example 4 and the nonwoven fabric coated with the air purification coating of Reference Example 1, as representative examples. For the air purification performance test, a sample of papermaking material (50mm x 50mm) was placed in a 10L Tedlar® bag and sealed with heat seal. 12L of air was then injected into the bag via a sleeve using an air pump (air blower), and ozone generated by an ozone generator was injected for 7 seconds. The initial ozone concentration was measured using an ozone monitor, and further measurements were taken every 15 minutes (under no-wind conditions and at room temperature of 25°C). Figure 13 shows the results of the ozone decomposition rate measurements over time. The ozone decomposition rate was calculated by comparing it with the initial ozone concentration. As shown in Figure 13, the papermaking material of Example 4 exhibited ozone decomposition and removal performance similar to that of the nonwoven fabric coated with the air purification coating of Reference Example 1.

[0102] Thus, the papermaking bodies of Examples 1 to 5 are mixed papermaking bodies of organic fibers containing fibrillated fibers and a manganese dioxide-based catalyst and / or activated carbon. The manganese dioxide-based catalyst and activated carbon are entangled and captured by the fibrils and fixed to the fibers, thereby providing the papermaking bodies with air purification performance due to the manganese dioxide-based catalyst and / or activated carbon. In the above embodiment, the activated carbon was in powder form, but when implementing the present invention, even if fibrous activated carbon (activated carbon fibers) is used, the fibrils will entangle the fibrous activated carbon and fix it to the fibers, resulting in a papermaking material with air purification performance. Furthermore, when implementing the present invention, powdered activated carbon and fibrous activated carbon may be used in combination.

[0103] As described above, the papermaking body of the above embodiment is a mixed papermaking body in which one or more types of organic fibers and powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon are mixed, and the organic fibers include fibrillated fibers. That is, the papermaking body of this embodiment consists of a mixed papermaking body in which at least one or more types of organic fibers including fibrillated fibers and powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon are mixed. Therefore, the manganese oxide-based catalyst and / or activated carbon are entangled and captured by the fibrils of the fibrillated fibers and fixed to the fibers, and the ability to remove harmful substances such as ozone and VOCs from the atmosphere, i.e., air purification performance, is imparted by the manganese oxide-based catalyst and / or activated carbon fixed to the fibers by the entanglement of the fibrils of the fibrillated fibers, without the application of an air purification coating, i.e., without the attachment of the manganese oxide-based catalyst and / or activated carbon to the fibers by a resin binder included in the coating.

[0104] According to the papermaking body of the above embodiment, instead of applying an air purification coating and attaching the manganese oxide-based catalyst and / or activated carbon to the fiber surface with a binder such as resin, the manganese oxide-based catalyst and / or activated carbon are captured by the fibrils of the fibrillated fibers and fixed and supported on the fibers. Therefore, the decrease in the air contact rate and activity of the manganese oxide-based catalyst and / or activated carbon due to masking is suppressed, the air purification performance of the manganese oxide-based catalyst and / or activated carbon can be effectively exhibited, and the air purification efficiency can be increased.

[0105] Furthermore, if a papermaking material is made from organic fibers containing fibrillated fibers and a manganese oxide-based catalyst and / or activated carbon, the activated carbon and manganese oxide-based catalyst can be distributed not only on the surface of the papermaking material but also inside. Moreover, because it is a porous material with interconnected voids, when air passes through the interconnected voids between the fibers of the papermaking material, harmful substances such as ozone and VOCs in the passing air can be decomposed and removed by the action of the manganese oxide-based catalyst and / or activated carbon, thereby improving the efficiency of air purification.

[0106] Furthermore, according to the papermaking body of the above embodiment, since it is a mixed papermaking body of organic fibers including fibrillated fibers and powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon, compared to the case in which air purification performance is imparted to a nonwoven fabric by applying an air purification coating containing resin, manganese oxide-based catalyst and / or activated carbon, the effort and cost of preparing and applying an air purification coating containing resin, manganese oxide-based catalyst and / or activated carbon and a dispersant can be reduced, and painting technology is not required. Therefore, productivity can be increased and costs can be reduced.

[0107] In the papermaking body of the above embodiment, the strength and rigidity can be further increased by including a binder to which organic fibers are bonded. In particular, if the binder is a binder fiber, it becomes difficult to mask manganese oxide-based catalysts and activated carbon.

[0108] In the papermaking body of the above embodiment, by further including non-fibrillated organic fibers, it becomes easy to control properties such as density, air permeability, and rigidity, and it also becomes easy to increase air permeability. In particular, non-fibrillated fibers are inexpensive if they are one or more of the following: polyester fibers, polyurethane fibers, nylon fibers, polypropylene fibers, and acrylic fibers.

[0109] In the papermaking body of the above embodiment, if the fibrillated fibers are one or more of acrylic fibers, polyamide fibers, and cellulose fibers, it is possible to improve the scavenging ability to manganese oxide-based catalysts and / or activated carbon at low cost.

[0110] In the papermaking body of the above embodiment, the basis weight is preferably 20 to 500 g / m². 2 , comfortably, 20-300g / m 2 More preferably, 50-200 g / m² 2 Within that range, it is easy to handle and ensures good ventilation.

[0111] In the papermaking body of the above embodiment, if the manganese oxide-based catalyst is a manganese dioxide-based catalyst, the catalytic activity is high, and it is possible to improve the ozone decomposition performance and air purification performance.

[0112] In the papermaking body of the above embodiment, if the manganese oxide-based catalyst has an average particle size preferably in the range of 0.1 to 10 μm, more preferably 0.5 to 8 μm, and even more preferably 1 to 5 μm, the air purification efficiency relative to the amount of manganese oxide-based catalyst attached can be increased.

[0113] In the papermaking body of the above embodiment, the activated carbon has a BET specific surface area of ​​preferably 500 m². 2 / g or more, 3000m 2 / g, comfortable, 600m 2 / g or more, 2500m 2 It is less than or equal to / g, and more preferably 700m 2 / g or more, 2000m2 If the amount is within the range of / g or less, the air purification efficiency relative to the amount of activated carbon attached can be improved.

[0114] In the papermaking body of the above embodiment, if the fibrillated fibers have a CSF value preferably in the range of 30 to 700 ml, more preferably 200 to 600 ml, and even more preferably 300 to 500 ml, then the scavenging ability to manganese oxide-based catalysts and / or activated carbon can be increased, and good aeration can be ensured.

[0115] The above description of the embodiment can also be interpreted as an invention of a method for producing a paper product obtained by wet-processing a papermaking slurry, which is made by mixing at least one or more organic fibers including fibrillated fibers with a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon and a dispersion medium, and then drying it. The papermaking method of the above embodiment provides the ability to remove harmful substances such as ozone and VOCs from the atmosphere, i.e., air purification performance, through the attachment of the manganese oxide-based catalyst and / or powdered or fibrous activated carbon to the fibers by the entanglement of the fibrils of the fibrillated fibers, rather than by the application of an air purification coating, i.e., by the attachment of the manganese oxide-based catalyst and / or activated carbon to the fibers by a resin binder included in the coating.

[0116] Incidentally, since the papermaking material of the above embodiment is in the form of a sheet, it can be used in various ways, such as by attaching it to a wall or pillar, or by hanging it up. Furthermore, although the above embodiment describes the use of the papermaking material for air purification purposes such as ozone purification sheets, it is not limited to that. The papermaking material of the present invention can also be used, for example, as a filter, an insect repellent sheet, or a deodorizing sheet, and can be utilized in a variety of uses and a wide range of applications.

[0117] Furthermore, when implementing the present invention, the configuration, composition, blending, components, shape, process, etc., of the papermaking body and other parts of its manufacturing method are not limited to this embodiment and example. Also, the numerical values ​​given in this embodiment and example do not represent critical values, but rather suitable values ​​for implementation, so slightly changing the above numerical values ​​does not negate the possibility of implementation.

Claims

1. A papermaking body characterized by comprising a mixed material obtained by mixing one or more organic fibers containing fibrillated fibers with a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon.

2. Furthermore, the papermaking body according to claim 1 is characterized by including a binder that bonded the organic fibers together.

3. The papermaking body according to claim 2, characterized in that the binder is a binder fiber.

4. The papermaking body according to claim 1, characterized in that the organic fibers further include non-fibrillated fibers.

5. The papermaking article according to claim 1, characterized in that the fibrillated fiber is one or more of the following: fibrillated acrylic fiber, fibrillated polyamide fiber, and fibrillated cellulose fiber.

6. The papermaking body according to claim 4, characterized in that the non-fibrillated fiber is one or more of the following: polyester fiber, polyurethane fiber, nylon fiber, polypropylene fiber, and acrylic fiber.

7. The aforementioned papermaking material has a basis weight of 20 to 500 g / m². 2 The papermaking body according to claim 1, characterized in that it is within the range.

8. The papermaking body according to claim 1, characterized in that the manganese oxide-based catalyst is a manganese dioxide-based catalyst.

9. The papermaking body according to claim 1, characterized in that the manganese oxide-based catalyst has an average particle size in the range of 0.1 μm to 10 μm.

10. The activated carbon has a BET specific surface area of ​​500 m². 2 / g or more, 3000m 2 The paper product according to claim 1, characterized in that it is within the range of / g or less.

11. The papermaking body according to claim 1, characterized in that the fibrillated fibers have a CSF value in the range of 30 to 700 ml.

12. A method for producing a paper product, characterized by wet-processing a papermaking slurry obtained by mixing one or more organic fibers containing fibrillated fibers, a powdered manganese oxide-based catalyst and / or powdered or fibrous activated carbon, and a dispersion medium, and then drying it.

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