JPH11117194A - Deodorizing paper and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a deodorizing paper having a combination of deodorizing ability, antimicrobial effect and VOC-decomposing ability, by providing at least one side of a substrate paper with an ultraviolet-absorbing layer followed by laminating the layer with a photocatalyst-contg. layer containing expandable microcapsules. SOLUTION: At least one side of a substrate paper with its flame retardancy rank (JIS A1322) corresponding to flameproofness grade 1 or 2 is provided with an ultraviolet-absorbing layer at a coating level of 3-20 g/m<2> followed by coating the layer with 5-20 g/m<2> of a coating liquid comprising 30-90 pts.wt. of a photocatalyst such as titanium oxide, 2-30 pts.wt. of an organic binder such as tetrafluoroethylene emulsion, 8-40 pts.wt. of an inorganic binder such as colloidal silica, and 0.5-5 pts.wt. of expandable microcapsules, and then drying under heating to expand the microcapsules to effect increasing the specific surface area, thus obtaining the objective deodorizing paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing paper using a photocatalyst and its use, and more particularly, to deodorizing, antibacterial, and VOC.
The present invention relates to a photocatalytic deodorizing paper using a photocatalyst having a decomposition performance and improving photocatalytic efficiency using microcapsules.

[0002]

[Prior art]

2. Description of the Related Art In recent years, as environmental reviews including environmental assessments are being conducted on a global scale, people are increasingly motivated to review their surroundings in order to further improve their living environments. In the last few years, words such as "antibacterial", "antifungal" and "bactericidal effect" have been frequently seen in daily life. For example,
Words such as "antibacterial" are often added as a function of increasing the commercial value, such as a mechanical pen, a ballpoint pen, a notebook, an automobile handle, a sheet, a plastic kitchen utensil, and the like.

[0003] One of the reasons for the public's particular interest in antibacterial activity is that the outbreak of pathogenic E. coli O-157 in 1996 caused many deaths. The incident has triggered more antimicrobial products on the market. On the other hand, HIV and MRSA hospital-acquired infections are unavoidable problems that will become major social problems in the aging society of the 21st century. Therefore, in recent years, photocatalysts have been spotlighted as one means for solving such problems. Above all, photocatalytic titanium oxide, which has excellent photocatalytic ability and is safe for the human body, is often used, and research and development in various forms are being carried out.

[0004] Titanium oxide, one of the photocatalysts, has been used industrially as a white pigment in a wide range of fields such as papermaking, plastics, paints, and cosmetics. The reason is that titanium oxide functions as an ultraviolet absorber to absorb ultraviolet light of 300 to 400 nm well and is inexpensive.

When titanium oxide itself is used as an ultraviolet absorber, the titanium oxide absorbs ultraviolet rays and generates electron and hole pairs, and the hole pairs react with water on the surface to form hydroxyl groups having strong oxidizing power. Generates active oxygen species such as radicals. Therefore, conventionally, titanium oxide that has been subjected to a surface treatment to prevent the reaction between the hole pair and moisture and suppress the generation of active oxygen species has been used as an ultraviolet absorber.

[0006] In recent years, photocatalysts such as titanium oxide have been reviewed, and a movement has been taking place in the industry to actively exert oxidizing power, which has been regarded as a drawback. Namely, the oxidizing power of the active oxygen species of most organic substances and NO _X and S
Inorganic materials such as O _X has been found to have ability to resolve, JP-A 7-102678 and JP-A No. 8-1
Japanese Patent No. 75887 discloses a ceramic or ceramic structure for preventing hospital-acquired infection, and Japanese Patent Application Laid-Open No. 8-173520 discloses a decorative article for environmental purification.

One of the reasons why the photocatalyst having this photocatalytic effect has been reconsidered is that, as a deodorant, it is permanent unlike an adsorbent deodorant such as activated carbon, and when viewed as a disinfectant, it is chlorinated, acidic, and so on. It is harmless without affecting the human body like alkaline germicides.

[0008] The application of photocatalyst to paper has been very difficult because the oxidizing action of the photocatalyst decomposes adjacent cellulose fibers and lowers the strength. However, in order to solve the problem, Japanese Patent Application Laid-Open No. 8-266602 discloses a titanium oxide-containing paper capable of suppressing a decrease in strength by preaggregating photocatalytic titanium oxide in water to reduce the area in contact with cellulose fibers. Japanese Patent Application Laid-Open No. Hei 8 (1996) discloses a method in which fine fibers and titanium oxide are aggregated to utilize hydrogen bonds of cellulose fibers in order to improve the yield of photocatalysts.
-266601. Japanese Patent Application Laid-Open No. Hei 8-120594 proposes a method in which the transparency of the entire paper is improved in order to effectively utilize the photocatalyst inside the paper, and light is transmitted to the internal photocatalyst.

As a method for supporting a photocatalyst on paper, there are an internal addition method obtained by internally adding a raw material and making a paper by a conventional method, and a coating method of applying a material prepared by coating a photocatalyst. As a coating method, JP-A-8-173805 discloses a method in which a cellulose fiber used for a base paper is treated with a water-soluble inorganic substance, water-insolubilized to form a base paper, and a photocatalytic titanium oxide layer is provided thereon. In the gazette, a method in which a film-forming inorganic material-containing layer is provided between the base paper and the photocatalyst layer to prevent a direct contact between the base paper and the photocatalyst, thereby suppressing a decrease in strength and improving durability. Is disclosed in
No. 173762.

[0010]

The method of supporting a photocatalyst on paper can be roughly classified into an internal addition method and a coating method. However, since the photocatalyst is basically a surface reaction, the photocatalyst reaction can be efficiently carried out. For this to occur, it is indispensable that the photocatalyst is exposed to light and that the substance to be decomposed contacts or approaches the photocatalyst. Considering this, it can be seen that internal addition is not an effective method because light hardly penetrates into the paper. Therefore, considering that light easily reaches the photocatalyst and the decomposable substance is easily contacted or approached, it is clear that the coating method in which the photocatalyst is coated on paper and present as a photocatalyst coating layer on the surface is excellent. It is.

In the present invention, the specific surface area of the photocatalytic titanium oxide-containing layer is increased by using the foamable microcapsules to foam the foamable microcapsules by the heat applied during the step of coating the photocatalyst-containing layer on paper. An object of the present invention is to provide a deodorized paper having an improved deodorizing ability. Furthermore, a photocatalyst-containing layer and an ultraviolet-absorbing layer are sequentially provided on a base paper to cut off ultraviolet rays from the base paper, thereby simultaneously providing a photocatalytic deodorized paper in which the strength is not reduced by the ultraviolet light.

[0012]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, provided a layer for simply preventing the photocatalyst-containing layer from directly contacting the base paper on the support. Focusing on the fact that ultraviolet rays that cannot be absorbed by the photocatalyst-containing layer and the like cause decomposition of the cellulose fibers in the base paper and reduce the strength of the base paper, It has been found that if one ultraviolet absorbing layer is provided between the base paper and the photocatalyst containing layer, the durability can be remarkably improved.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The deodorized paper of the present invention requires at least three layers in the order of a base paper, an ultraviolet absorbing layer and a photocatalyst containing layer. This can have a layer structure of four or more layers as necessary, and can be provided on both sides of the base paper in the order of at least an ultraviolet absorbing layer and a photocatalyst containing layer.

The papermaking fibers used in the base paper of the present invention include softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), and hardwood bleached kraft pulp (LBK).
P), wood pulp such as softwood bleached sulphite pulp (NBSP), thermomechanical pulp (TMP), non-wood pulp such as kozo, mitsumata, straw, hemp, bamboo, straw, linter, bagasse, kenaf and espart, and polyolefin Or a mixture of synthetic fibers such as synthetic pulp, rayon, vinylon, nylon and polyester.

In the production of the base paper, a coloring agent such as a dye or a pigment is added to the papermaking fiber as described above, if necessary, and if necessary, various fillers such as clay and calcium carbonate are added in an amount of 30 to 30%. 75% by weight high filling, sizing agents such as rosin and alkyl ketene dimer, dry paper strength agents such as starch and polyacrylamide, wet paper strength agents such as melamine resin, polyamine / polyamide / epichlorohydrin resin, sulfuric acid A conventional papermaking auxiliary material such as a band and a fixing agent such as polyacrylamide is appropriately used in combination, and the paper is formed using a fourdrinier paper machine or a circular net paper machine in a conventional manner.

When the base paper needs to be flame-retardant or non-flammable, it may be subjected to a flame-retardant treatment during or after papermaking. As a flame retardant, guanidine sulfamate, guanidine phosphate, ammonium sulfamate, a condensed phosphate alkyl ester derivative, guanidine sulfate, ammonium phosphate, ammonium sulfate, calcium chloride, magnesium chloride, borax, boric acid, and the like are dispersed in an aqueous solution or water. Anything that can be used can be used. As another method, there is a method of blending powder in an amount of 65% by weight or more to achieve flame retardancy and non-flammability.

Further, in order to improve the flame retardancy of the base paper surface, a paint containing a substance having water of crystallization such as aluminum hydroxide and magnesium hydroxide as a main component can be applied.

The types of base paper that can be used in the present invention include:
Art paper, coated paper,
Printing information paper represented by high-quality paper, kraft paper, and the like, packaging paper, hybrid paper, cardboard base paper, nonwoven fabric, and the like can be given.

The photocatalyst used in the present invention includes metal oxides such as titanium oxide, zinc oxide, tin oxide, tungsten oxide, niobium oxide, zirconium oxide and cerium oxide, cadmium sulfide, zinc sulfide, lead sulfide, copper sulfide, and the like. At least one known photocatalyst particle such as a metal sulfide such as molybdenum sulfide can be selected and used. Among them, titanium oxide is preferred because of its excellent photocatalytic activity, chemical stability, harmlessness to the human body, and relatively low cost.

The titanium oxide described in the present invention means various titanium oxides such as anatase-type titanium oxide, rutile-type titanium oxide, amorphous titanium oxide, metatitanic acid and orthotitanic acid, or titanium hydroxide and hydrous titanium hydroxide. I do.

In order for the photocatalyst of the present invention to decompose harmful substances and the like by a photocatalytic reaction, it is necessary to irradiate the photocatalyst with light having a wavelength having an energy greater than the band gap. Therefore resulting reactive oxygen species ^{_{(OH ·, · O 2 -}} , such as H ₂ O ₂₎
Decomposes harmful substances and finally to end products such as carbon dioxide and water. By such an action,
Bactericidal and antibacterial effects occur.

Examples of harmful substances include aldehydes,
Amines, there hydrocarbons such as alcohols, trihalomethane, tetrachlorethylene, the organic halogen compounds Freon or SO _X, NO _X and the like. In addition, degradable substances include BOD, pesticides, proteins, amino acids and the like, and sterilization of fungi, molds and the like is also possible.

The light source for irradiating the photocatalyst with light having a wavelength having an energy equal to or greater than the band gap, ie, light having a wavelength of 400 nm or less, includes ultraviolet light such as sunlight, a fluorescent lamp, a mercury lamp, a xenon lamp, and a black light. Is mentioned.

In the present invention, an ultraviolet absorbing layer can be provided on the base paper, and the ultraviolet light that could not be absorbed by the layer closer to the light source than the absorbing layer is absorbed by this layer, thereby affecting the base paper. It is provided for the purpose of suppressing.

The life of the base paper is improved by absorbing a high energy wavelength, ie, ultraviolet light, which causes a reduction in the strength of the cellulose fiber. The wavelength region that the ultraviolet absorbing layer desirably absorbs is ultraviolet light of 400 nm or less, and it is particularly desirable to absorb light on the short wavelength side.

The microcapsules used for increasing the specific surface area of the photocatalytic titanium oxide-containing layer are obtained by encapsulating a low-boiling solvent in resin fine particles, and have a diameter of 3 to 5 times at a relatively low temperature of 70 to 150 ° C. The particles having an average particle diameter of 5 to 30 μm which expand 10 to 120 times in volume.

As the resin, a thermoplastic resin composed of a copolymer such as vinylidene chloride, acrylonitrile, acrylate or methacrylate is used.
As the low-boiling solvent, a low-boiling solvent such as isobutane, pentane, petroleum ether, hexane, or a low-boiling halogenated hydrocarbon is usually used. As a method for producing the expandable microcapsules, any conventionally known methods can be used.

When the foamable microcapsules are heated to a temperature higher than the softening point of the resin forming the outer shell, the resin starts to soften, and at the same time, the encapsulated low-boiling solvent vaporizes and the vapor pressure rises. The resin is pushed apart and swells to form closed cells. If the heating is further continued, the air bubbles are broken and become crater-like, so that the specific surface area can be increased.

These effervescent microcapsules include “Matsumoto Microsphere F-30D”, “F-20D”, and “Matsumoto Microsphere” manufactured by Matsumoto Yushi Seiyaku Co., Ltd.
F-50D "and" EXPANCEL WU "and" DU DU "sold by Nippon Philite Co., Ltd. are known, but the foamable microcapsules used in the present invention are not limited to these.

The filler used in the ultraviolet absorbing layer may be a powdery substance used as a photocatalyst, which has been subjected to surface treatment to reduce or eliminate the photocatalytic activity, or titanium oxide or zinc which has been conventionally used as a cosmetic or paper additive. Hua is a typical example, and a micro-encapsulated ultraviolet absorber is used as appropriate.

As the substance to be used as a binder of the ultraviolet absorbent in the ultraviolet absorbing layer, any substance which can be dissolved or dispersed in water or a solvent can be selected, but it is preferable to select an aqueous formulation from the viewpoint of production cost.

Examples of the organic binder that can be dissolved or dispersed in water include styrene-butadiene latex,
Modified styrene-butadiene latex, acrylonitrile-butadiene latex, methyl methacrylate-butadiene latex, modified methyl methacrylate-butadiene latex, chloroprene latex, butyl latex, polybutene latex, polyurethane latex, thiochol latex, polyethylene emulsion, ethylene vinyl acetate emulsion, chloride Aqueous latex such as vinylidene emulsion, vinyl chloride emulsion, polytetrafluoroethylene emulsion and the like, and water-based emulsion and synthetic and natural polymers such as polyvinyl alcohol, carboxymethyl cellulose, starch, casein, etc. can be used alone or in combination of two or more. .

The reason for providing the ultraviolet absorbing layer is to absorb the light having a wavelength of 400 nm or less as described above. Therefore, in addition to the filler and binder used in the ultraviolet absorbing layer, the entire ultraviolet absorbing layer has a wavelength of 400 nm or less. Any material that can emit light can be used by appropriately selecting a coating layer, a film, a vapor deposition layer, and the like.

As the binder of the photocatalyst used in the photocatalyst-containing layer, the above-mentioned binder of the ultraviolet absorbent of the ultraviolet absorbing layer can be used. However, organic resins resistant to oxidative deterioration, such as fluororesin such as polytetrafluoroethylene emulsion and silicon resin, can be used. It is preferable to use a system-based binder.

In the photocatalyst-containing layer of the present invention, an inorganic binder can be used in combination with an organic binder in order to prevent oxidative deterioration due to the oxidizing action of the photocatalyst. With this combination, the coated surface is less likely to break when a stress is applied to the paper, such as during corrugating, as compared to the case where only the inorganic binder is used. This is because if only an inorganic binder is used, it becomes a glass-like coated surface after drying, and cracks are generated by applying only a small stress, and it is easy to fall off. However, when an organic binder is used in combination, the organic binder acts as an adhesive at a cracked portion, so that the crack does not become large, so that it is difficult to break. Furthermore, the inorganic binder alone floats on the surface because it is impossible to stay inside the coating layer due to a difference in specific gravity from the microcapsule during foaming. However, by using an organic binder together, it is possible to effectively foam inside the coating layer.

As the inorganic binder, a film-forming inorganic material such as colloidal silica, colloidal alumina, saponite, hectorite, smectite, and sepiolite can be used. Inorganic compounds which can act as a binder include the inorganic compounds listed above. Any can be used without limitation.

[0037]

EXAMPLES Example 1 Noncombustible base paper (trade name: TT-120C, Tokushu Paper Co., Ltd.)
Manufacturing), photocatalytic titanium oxide (trade name: PC-101,
50 parts by weight, inorganic binder (trade name: Snowtex C, manufactured by Nissan Chemical Co., Ltd.)
10 parts by weight, organic binder (trade name: Polyrac 7)
50, manufactured by Mitsui Toatsu Chemicals, Inc .; 5 parts by weight; expandable microcapsules (trade name: Matsumoto Microsphere F-20D, manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.); A deodorized paper was obtained by applying 10 g / m ^{2 by} weight and drying by heating.

Example 2 An organic binder (trade name: 90 parts by weight) of titanium oxide (trade name: KRONOS KA-80, manufactured by Titanium Industry Co., Ltd.) was added to a noncombustible base paper (trade name: TT-120C). 5 g / m ^{2 of} an ultraviolet absorbing layer containing 10 parts by weight of Polylac 750), and 50 parts by weight of photocatalytic titanium oxide (trade name: PC-101) and an inorganic binder (trade name: Snowtex C) ) 10 parts by weight, 10 parts by weight of an organic binder (trade name: Polylac 750),
A photocatalyst-containing layer containing 2 parts by weight of expandable microcapsules (trade name: Matsumoto Microsphere F-20D) was applied at a dry weight of 10 g / m ² , and dried by heating to obtain a deodorized paper.

Example 3 An organic binder (trade name: Polylac 750) 10 with 90 parts by weight of titanium oxide (trade name: KRONOS KA-80) on a non-combustible base paper (trade name: TT-120C)
An ultraviolet absorbing layer containing 10 parts by weight is coated at 10 g / m ^2, and a titanium oxide photocatalyst (trade name: PC-101) is further applied thereon.
50 parts by weight, 10 parts by weight of an inorganic binder (trade name: Snowtex C), 20 parts by weight of an organic binder (trade name: Polylac 750), 5 parts by weight of expandable microcapsules (trade name: Matsumoto Microsphere F-20D) The photocatalyst-containing layer including the part was coated at a dry weight of 20 g / m ² and dried by heating to obtain a deodorized paper.

Example 4 A non-combustible base paper (trade name: TT-120C) was mixed with an organic binder (trade name: 80 parts by weight) of titanium oxide (trade name: Taipaque R-820, manufactured by Ishihara Sangyo Co., Ltd.). Polyrac 515-6, manufactured by Mitsui Toatsu Chemical Industry Co., Ltd.) 20
5 g / m ^{2 of} an ultraviolet absorbing layer containing a weight part, and 70 parts by weight of a photocatalytic titanium oxide (trade name: ST-01, manufactured by Ishihara Sangyo Co., Ltd.) and an inorganic binder (trade name: Snowtex C) 20 parts by weight, organic binder (trade name: Clear E, manufactured by Tsuneka Chemical Industry Co., Ltd.)
A deodorizing paper is obtained by applying a photocatalyst-containing layer containing 10 parts by weight and 5 parts by weight of expandable microcapsules (trade name: Matsumoto Microsphere F-20D) at a dry weight of 15 g / m ² and drying by heating. Was.

Example 5 Photocatalytic titanium oxide (trade name: S) was used as base paper (PPC paper).
T-21, manufactured by Ishihara Sangyo Co., Ltd.) 80 parts by weight, inorganic binder (trade name: Snowtex C) 10 parts by weight,
A photocatalyst-containing layer containing 10 parts by weight of an organic binder (trade name: Clear E) and 1 part by weight of expandable microcapsules (trade name: Matsumoto Microsphere F-20D) is applied at a dry weight of 15 g / m ^2. After drying by heating, deodorized paper was obtained.

Example 6 An organic binder (trade name: Polylac 515-6) was added to 80 parts by weight of titanium oxide (trade name: Taipaque R-820, manufactured by Ishihara Sangyo Co., Ltd.) on base paper (PPC paper).
An ultraviolet absorbing layer containing 20 parts by weight was coated at 10 g / m ^2, and then a titanium oxide photocatalyst (trade name: ST-2)
1) 60 parts by weight, an inorganic binder (trade name: Snowtex C) 30 parts by weight, an organic binder (trade name:
Clear E) 10 parts by weight, foaming microcapsules (trade name: Matsumoto Microsphere F-20D) 3 parts by weight of 15 g / m ² coated on a dry weight photocatalyst-containing layer containing a deodorizing dried by heating I got the paper.

Comparative Example 1 50 parts by weight of a photocatalytic titanium oxide (trade name: PC-101) and 10 parts by weight of an inorganic binder (trade name: Snowtex C) were added to a noncombustible base paper (trade name: TT-120C). The coated photocatalyst containing layer is coated at a dry weight of 10 g / m ² ,
By heating and drying, deodorized paper was obtained.

Comparative Example 2 Non-combustible base paper (trade name: TT-120C), 90 parts by weight of titanium oxide (trade name: KRONOS KA-80), and an organic binder (trade name: Polyrac 750) 10
An ultraviolet absorbing layer containing 5 parts by weight is coated at 5 g / m ² , and photocatalytic titanium oxide (trade name: PC-101) 5 is further applied thereon.
2 g by weight of a photocatalyst-containing layer containing 0 parts by weight and 10 parts by weight of an inorganic binder (trade name: Snowtex C)
/ M ² and dried by heating to obtain deodorized paper.

Comparative Example 3 Non-combustible base paper (trade name: TT-120C), 50 parts by weight of photocatalytic titanium oxide (trade name: PC-101), 10 parts by weight of an inorganic binder (trade name: Snowtex C), foaming A photocatalyst-containing layer containing 20 parts by weight of hydrophilic microcapsules (trade name: Matsumoto Microsphere F-20D) was applied at a dry weight of 10 g / m ² and dried by heating to obtain deodorized paper.

Comparative Example 4 Photocatalytic titanium oxide (trade name: ST) was used as base paper (PPC paper).
-21) A photocatalyst-containing layer containing 80 parts by weight and 10 parts by weight of an organic binder (trade name: Clear E) was applied at a dry weight of 15 g / m ² and dried by heating to obtain a deodorized paper.

Comparative Example 5 Photocatalytic titanium oxide (trade name: S
T-21) A photocatalyst-containing layer containing 80 parts by weight, 2 parts by weight of an inorganic binder (trade name: Snowtex C), and 10 parts by weight of an organic binder (trade name: Clear E) is 15 g / m ² by dry weight. The deodorized paper was obtained by coating and drying by heating.

Table 1 shows the evaluation results of the deodorized papers obtained in Examples 1 to 6 and Comparative Examples 1 to 5. The evaluation was performed by the following method.

Evaluation of Deodorizing Performance Evaluation of the deodorizing performance was performed using the apparatus shown in FIG. 1 under the following conditions, and the formaldehyde concentration in the experimental apparatus was measured 5 hours after the start of light irradiation. Noxious gas: formaldehyde Initial formaldehyde gas concentration: 100 ppm Sample size: 10 cm × 20 cm UV intensity: 1 mW / cm ² Experimental equipment volume: 30 L Flow rate: 10 L / min

Evaluation of physical properties Auto fade meter manufactured by Suga Test Machine (model: FAI-
In AU-B), the bending strength of the deodorized paper after irradiating with light for 6 hours is evaluated according to the “Method of testing the bending strength of paper and paperboard with an MIT type tester” specified in JIS P 8115. Was. The displayed value is in the MD direction. For reference, the folding strength of TT-120C and PPC paper is shown in the lower part of the table.

Coating properties It was evaluated whether repelling, uneven coating, cracks during drying, etc. were observed during coating.

[0052] weathering manufactured by Suga Test Instruments Co. auto fade meter (Model: FAI-
AU-B), powder dropping after 6 hours of light irradiation, discoloration, and the like were observed.

[0053]

[Table 1]

From the results in Table 1, the following has been found. (1) In the deodorizing performance, it was found that Comparative Example 2 in which the coating amount of the photocatalyst-containing layer was small had a decomposition ability 2-3 times worse than the other samples, and the coating amount of the photocatalyst-containing layer was 5 to 5. 2
It is preferably adjusted to 0 g / m ² . If it is more than 20 g / m ² , the thickness of the coating layer becomes large, cracks are likely to occur at the time of coating or use, and at the same time, it can be expected that the performance is excessive.

(2) From the results of measuring the bending strength, it is possible to maintain the strength almost the same as that of the unirradiated base paper by providing the ultraviolet absorbing layer. However, since the photocatalyst layer itself has a property of absorbing ultraviolet light, no decrease in intensity due to extreme light irradiation is observed. However, it can be expected that this difference will appear clearly when used for a long time. Therefore, providing an ultraviolet absorbing layer is an effective means for preventing deterioration of the base paper.

(3) From the results of coating properties, Comparative Examples 1 to 3 using only the inorganic binder showed unevenness and cracks. This is because, when only an inorganic binder is used, the coated surface becomes a very hard film after drying, and thus the base paper is easily bent or broken, thereby easily cracking. Therefore, the use of the organic binder plays a major role in preventing cracking.

(4) From the results of the light resistance, in Comparative Example 4 using only an organic binder and Comparative Example 5 using an organic binder and a small amount of an inorganic binder, powder falling off due to light irradiation may occur. confirmed. This is considered to be because the surrounding organic binder was decomposed by the oxidizing action of the photocatalyst. Further, it was also revealed that the binder effect was not exhibited if the amount of the inorganic binder was too small.

[0058]

As described above, the photocatalytic deodorizing paper of the present invention has the following remarkable effects.

(1) When the foamable microcapsules are mixed with the photocatalyst-containing layer and dried by heating to foam, the specific surface area increases, and a deodorizing effect with high photocatalytic efficiency can be obtained.

(2) Since the base paper has an ultraviolet absorbing layer, deterioration of the base paper due to ultraviolet light can be prevented, and a decrease in physical properties can be suppressed.

(3) By mixing an inorganic binder, powder falling due to the oxidizing action of the photocatalyst can be prevented.

(4) By using an organic binder in combination, coating suitability is improved, and soiling can be performed more quickly when the coating machine is washed than when the inorganic binder is used alone.

(5) The coating layer can be efficiently foamed from inside by using an organic binder in combination.

(6) By using an organic binder in combination with an inorganic binder, cracks are less likely to occur during corrugating in the processing of deodorized paper and the like.

Taking advantage of the above properties, the deodorized paper obtained by the present invention can be used for air purifiers, deodorizers, wallpaper, antibacterial paper, sterilized paper, reflectors for lighting and the like.

[0066]

[Brief description of the drawings]

FIG. 1 is a test apparatus for evaluating the deodorizing performance of the deodorizing paper of the present invention.

FIG. 2 is a cross-sectional view of the deodorized paper of the present invention.

FIG. 3 is a sectional view of a deodorized paper provided with an ultraviolet absorbing layer of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circulation pump 2 Gas bag 3 Reactor 4 Photocatalytic deodorizing paper 5 UV lamp 6 Base paper 7 Photocatalyst containing layer 8 Foamable microcapsule 9 Ultraviolet absorbing layer

Claims (6)

[Claims] 1. A foamable microcapsule foamed on at least one surface of a base paper is added to the photocatalyst-containing layer in an amount of 0.5 to 0.5%.
A deodorized paper comprising a photocatalyst-containing layer containing 5 wt% of 5 to 20 g / m2. 2. A coating amount of 3 to 2 on at least one surface of the base paper.
A deodorizing paper comprising an ultraviolet absorbing layer of 0 g / m2, and the photocatalyst-containing layer having a coating amount of 5 to 20 g / m2 sequentially laminated thereon. 3. The photocatalyst-containing layer comprises 30 to 90 parts by weight of a photocatalyst, 2 to 30 parts by weight of an organic binder, 8 to 40 parts by weight of an inorganic binder, and 0.5 to 5 parts of foamable microcapsules.
The deodorized paper according to claim 1, comprising a weight part. 4. A flame-retardant type specified in JIS A 1322 "Test method for flame retardancy of thin building materials".
The deodorized paper according to any one of claims 1 to 3, wherein a base paper corresponding to any of the second grade is used. 5. A deodorizing method characterized in that the photocatalyst-containing layer is coated on at least one side of a base paper at 5 to 20 g / m 2 and heated and dried to expand foamable microcapsules, thereby increasing the specific surface area. Paper manufacturing method. 6. An at least one surface of the base paper is coated with an ultraviolet absorber layer in an amount of 3 to 20 g / m2 and dried, and the photocatalyst-containing layer is coated thereon in an amount of 5 to 20 g / m2 and dried by heating. A method for producing deodorized paper, wherein the specific surface area is increased by foaming microcapsules.