JPH10263411A - Adsorptive photocatalytic sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the function of decomposing harmful substances such as malodorous substances and polluting substances and post-processability of this adsorptive photocatalyst sheet by producing the sheet from a photocatalyst, an adsorbent, microbial cellulose, and a supporting body forming component. SOLUTION: This adsorptive photocatalyst sheet is constituted of a photocatalyst, an adsorbent, microbial cellulose, and a supporting bodyforming component. The photocatalyst is a photo-reactive semiconductor which has a prescribed forbidden band width and causes a photocatalytic reaction and a metal oxide particle of such as zinc oxide, tungsten oxide, titanium oxide, etc., is used, and titanium oxide is most preferable. The adsorbent is a porous substance which can adsorb a gas such as malodorous substances, and activated white clay, zeolite, sepiolite, and their compounded materials may be used. The microbial cellulose is a cellulosic substance produced by microbe. The supporting body-forming component is a component necessary to retain the shape and the state at the time when the adsorptive photocatalyst sheet is produced and synthetic resin, natural fiber, etc., may be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adsorptive photocatalyst sheet capable of decomposing harmful substances such as odorous substances and dirt substances by utilizing a photocatalytic reaction, and more particularly, to a photocatalyst and an adsorbent using microbial cellulose. The present invention relates to an adsorptive photocatalyst sheet efficiently held on a support and having an excellent antifouling effect.

[0002]

2. Description of the Related Art In recent years, with increasing interest in environmental issues, there has been an increasing demand for not only the removal of low-concentration harmful substances such as industrial exhaust and wastewater on an industrial level, but also the removal of offensive odors in daily life. ing. For the removal of low-concentration harmful substances, activated carbon, silica, alumina, and composite inorganic adsorbents such as metal oxides and the like are generally used as a malodor removing material in daily life, As the harmful substances are adsorbed on the adsorbent, there are a number of problems in use, such as the absorption capacity gradually decreasing.

On the other hand, in recent years, a method for removing harmful substances using a photocatalyst has been developed. JP-A-61-135669 discloses a method in which a photocatalyst such as zinc oxide is irradiated with ultraviolet light to decompose a sulfur compound as a malodorous substance. Further, Japanese Patent Publication No. 2-62297 discloses a method for removing low-concentration nitrogen oxides using a mixture of titanium oxide and activated carbon. The decomposition of malodorous substances by photocatalysts such as titanium oxide and zinc oxide is due to the photocatalytic oxidation of contact malodorous substances by the excitation of these actinic rays. Since it does not decrease basically as long as it is exposed to light, it has a great advantage as compared with the case where only the adsorbent is used.

[0004] In addition to the permanent deodorizing effect due to the decomposition of malodorous substances, the photocatalyst also decomposes organic contaminants,
It is known that it has an antifouling action to prevent its adhesion and an antibacterial action to prevent the growth of bacteria such as Escherichia coli.Adsorbent photocatalyst sheets containing such photocatalysts and adsorbents are used in various applications. is there.

As a method for obtaining an adsorptive photocatalyst sheet, Japanese Patent Application Laid-Open No. Hei 7-299354 discloses a method in which a carrier carrying a photocatalyst is included in a gas permeable sheet.
No. 1 discloses a method of firmly holding a photocatalyst using fine fibers. Above all, an adsorptive photocatalyst sheet in which a photocatalyst is firmly held by using fine fibers is excellent in post-processability in addition to the ability to remove odorous substances, but has a problem in that the antifouling effect is slightly inferior. Was. In recent years, air purifiers not only for business use but also for home use, for vehicle use and the like have come into widespread use, and miniaturization and thinning of these air purifiers have been desired, and furthermore, high deodorizing performance is high. There is a need for an adsorptive photocatalytic sheet.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an adsorptive photocatalyst sheet which is excellent in decomposability of harmful substances such as odorous substances and dirt substances, has excellent post-processing properties, and furthermore has excellent flame retardancy. To provide.

[0007]

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, have devised the following invention.

An adsorptive photocatalyst sheet comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component.

An adsorptive photocatalyst sheet obtained by wet-making an aqueous suspension comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component.

An adsorptive photocatalyst sheet obtained by wet-making an aqueous suspension comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component, wherein the aqueous suspension further contains a flocculant. Adsorbable photocatalyst sheet.

In an aqueous suspension comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component, the addition of a photocatalyst to the product of the microcatalyst cellulose photocatalyst / adsorbent retention index (A) and the amount of microbial cellulose added (B). Weight (C) and the total amount of the adsorbent (D) ((C
+ D) / (A × B)) is from 0.5 to 2.

An adsorptive photocatalyst sheet comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component,
An adsorptive photocatalytic sheet, wherein the microbial cellulose is a cellulosic substance produced by a stirring culture method.

In an adsorptive photocatalyst sheet obtained by wet-making an aqueous suspension comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component, the microbial cellulose is a cellulosic substance produced by a stirring culture method. An adsorptive photocatalyst sheet characterized by the following.

An adsorbent photocatalyst sheet comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component,
The adsorptive photocatalyst sheet, wherein the support-forming component is a flame-retardant substance.

An adsorptive photocatalyst sheet obtained by wet-making an aqueous suspension comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component, wherein the support-forming component is a flame-retardant substance. Adsorbable photocatalyst sheet.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The components relating to the adsorptive photocatalyst sheet of the present invention and the method for producing the same will be described below in detail.

The photocatalyst according to the present invention is 0.5 to 5 e
V, preferably a photoreactive semiconductor that provides a photocatalytic reaction with a band gap of 1-4 eV. Examples of such a photocatalyst according to the present invention include metal oxide particles such as zinc oxide, tungsten oxide, titanium oxide, and cerium oxide. In particular, titanium oxide has structural stability and photoreactive harmful substance removal. The photocatalyst according to the present invention is most suitable for use in a living space because of its performance and safety in handling, and is advantageously used as a photocatalyst according to the present invention.

Titanium oxide which is advantageously used as a photocatalyst includes titanium oxide such as metatitanic acid, orthotitanic acid, hydrous titanium oxide, hydrated titanium oxide and titanium hydroxide, in addition to general-purpose titanium dioxide used as a white pigment. Titanium hydroxide and the like can be mentioned. These titanium oxides are produced industrially by a gas phase combustion method, a hydrolysis method, a thermal decomposition method, or the like using titanium tetrachloride, titanium sulfate, or titanium oxide as a raw material. Among these, 10
Fine particle titanium oxide having an anatase structure centered on the size of nm or less is an excellent photocatalyst. Furthermore, there is a method using an organic titanate other than these production methods,
This method provides a highly uniform and transparent photoreactive film. In addition, Pt, A
u, Ag, Cu, Pd, Ni, Rh, Nb, Sn, Cr
And doping or doping metals such as Ru,
Other metal oxides such as ruthenium oxide, nickel oxide, manganese oxide, and iron oxide may be supported.

The mechanism for decomposing harmful substances in a photocatalyst generates free radicals on the surface of the photocatalyst when the photocatalyst receives active light, and the free radicals attack harmful substances in contact with the surface of the photocatalyst to decompose the harmful substances. In order to sufficiently exhibit this process, it is effective to increase the specific surface area of the photocatalyst and increase the free radical generation point. In addition, when the specific surface area is increased, the contact area with the harmful substance per unit amount of the photocatalyst is also increased. Therefore, in order to decompose the harmful substance, the larger the specific surface area is, the more effective.

However, as the specific surface area of the photocatalyst is increased, the stability of the photocatalyst itself is reduced, the cohesion is increased, and the dispersion is difficult, and the contact of harmful substances cannot be substantially improved. Therefore, the specific surface area of the photocatalyst according to the present invention is preferably about 50 to 500 m ² / g, more preferably 100 to ⁵ m ² / g.
About 00 m ² / g is good. In particular, in the case of titanium oxide, the specific surface area is preferably about 50 to 400 m ² / g, and more preferably about 150 to 350 m ² / g.

The adsorbent of the present invention is a porous substance capable of adsorbing a gas such as an odorous substance, and comprises activated clay, zeolite,
Examples include sepiolite, halloysite, zinc oxide, silica, alumina, activated carbon, and composites thereof. The adsorbent of the present invention temporarily stores the odor substance when it is necessary to remove a large amount of odor substance exceeding the decomposition ability of the photocatalyst, and when the photocatalyst is not irradiated with sufficient photocatalyst excitation light. It is something to put. Further, the adsorbent of the present invention can also act as a carrier for a photocatalyst, and by holding the photocatalyst on the carrier, improves the holding power on the support-forming component. In particular, in the adsorptive photocatalyst sheet using the flame retardant substance according to the sixth invention as a support-forming component, the use of an adsorbent having low flame retardancy such as activated carbon needs to be suppressed to a small amount. It is preferable to use an inorganic adsorbent or the like.

The microbial cellulose of the present invention is a cellulosic substance produced by a microorganism, and in addition to cellulose, a heteropolysaccharide having cellulose as a main chain, β-1,3,
It contains glucans such as β-1, 2 and the like. The constituent components other than cellulose in the case of the heteropolysaccharide are hexoses, pentoses such as mannose, fructose, galactose, xylose, arabinose, rhamnose, and glucuronic acid, and organic acids.

The microorganism producing cellulose is not particularly limited, but may be Acetobacter xylinum (Acetobacter).
obactor xylinum ATCC 10821, Acetobactor xylinum subsp. sucrofermentans
tans) BPR2001 strain (FERM BP-454)
5), Acetobacter pasteurianus (A. pasteur)
iunus) and other genus Agrobacterium, Rhizobium, Sarsina, Pseudomonas, Achromobacter, Alcaligenes, Aerobacter, Azotobacter and Zugrea, and treatment with nitrosoguanidine and the like. And various types of mutant strains that are created by performing a mutation treatment by a known method such as ultraviolet irradiation or the like, and that produce a cellulosic substance can be used.

As a method for culturing microbial cellulose, stationary culture, shaking culture, stirring culture and the like can be used. Among them, the microbial cellulose used in the present invention is preferably produced by a stirring culture method in which a culture solution is stirred. As a stirring means in the stirring culture method, for example, an impeller, an airlift fermenter, a pump-driven circulation of a fermentation broth and the like can be used.

As the culturing method, there are a so-called batch fermentation method, a fed-batch batch fermentation method, a repeated batch fermentation method and a continuous fermentation method. As a tank for performing the stirring culture, for example, a stirring tank such as a jar fermenter and a tank, a flask with a baffle, a Sakaguchi flask, and an air-lift type fermenter can be used.

In the stirring culture of the present invention, the culture solution may be aerated as needed at the same time as the stirring. For example, when cultivating an anaerobic microorganism, the culture solution can be stirred by passing an inert gas such as argon and nitrogen containing no oxygen. In the case of culturing aerobic microorganisms, the culture solution can be agitated while supplying oxygen necessary for the growth of microorganisms and the production of cellulosic substances by aerating an oxygen-containing gas. The agitation by aeration and the agitation using an impeller or the like can be used in combination. In addition, about the type and culture method of the microorganism used for culture, for example,
It is known that acetic acid bacteria include a strain suitable for stationary culture and a strain suitable for stirring culture, and it is preferable to select the strain according to the culture method.

The microbial cellulose used in the present invention is preferably subjected to a defibration treatment. The defibration process is 6-72
No. 394, etc., using a stirring type disintegration apparatus such as a mixer, PCT / US92 / 09642.
A method using a high-pressure homogenizer described in the specification can be used. The change due to the fibrillation treatment of the microbial cellulose is, for example, that the bulk microbial cellulose obtained by static culturing of acetic acid bacteria becomes a homogeneous sediment with low sedimentation in an aqueous system, and, for example, stirring of the acetic acid bacteria In the case of microbial cellulose in a fiber suspension in an aqueous system obtained by culturing, a decrease in sedimentation described in JP-A-7-118303, that is, an improvement in homogeneity and a method described in JP-A-7-119.
A decrease in drainage described in No. 067 is observed.

The photocatalyst / adsorbent retention index of microbial cellulose is a ratio indicating the weight of photocatalyst and adsorbent that can be retained by a unit weight of microbial cellulose, and is a dimensionless quantity. To determine the photocatalyst / adsorbent retention index of microbial cellulose, microbial cellulose, a sufficient amount of photocatalyst for microbial cellulose, adsorbent, support-forming component, and if necessary, an aqueous suspension comprising a flocculant, TAPP
A test is performed in accordance with the retention operation in I standard method T261pm-79 "fine fiber content of stock by wet screening". The remaining amount of the photocatalyst and the adsorbent obtained from the test results (E), the remaining amount of the photocatalyst by the support-forming component obtained from the test results without adding microbial cellulose (F), and the remaining amount of the microbial cellulose (G) ), The photocatalyst / adsorbent retention index (A) is determined by the equation represented by Equation 1.

[0029]

## EQU1 ## Photocatalyst / adsorbent retention index (A) = (EF) / G

When the addition amount of the photocatalyst and the adsorbent is fixed and the addition amount of the microbial cellulose is gradually increased from 0, the remaining amount of the photocatalyst and the adsorbent increases almost linearly, and then becomes saturated. Although it is confirmed that the photocatalyst and the adsorbent have a sufficiently large amount with respect to the microbial cellulose, the remaining amount of the photocatalyst and the adsorbent increases almost linearly and becomes saturated. Until it is reached, the amount of microbial cellulose is less than the amount of photocatalyst and adsorbent. In addition, when determining the amount of microbial cellulose retained, since the measurement error is large in such a range where the amount of microbial cellulose is relatively small, for example, the amount of microbial cellulose added to the support-forming component The test is performed by shaking stepwise to about 0 to 10% by weight, and the amount of microbial cellulose remaining is plotted against the amount of microbial cellulose added. It is necessary to add a correction, for example, to obtain the amount of remaining.

An aqueous suspension comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component, preferably an aqueous suspension further containing an aggregating agent, is wet-formed into an adsorptive photocatalyst sheet. Photocatalyst / adsorbent retention index (A) and amount of microbial cellulose added (B)
Weight ratio of the addition amount of photocatalyst (C) and the addition amount of adsorbent (D) to the product of ((C + D) / (A × B))
Is preferably 0.5 to 2.

The above weight ratio ((C + D) / (A × B))
Is smaller than 0.5, there is a problem of powder falling off the sheet during processing, and furthermore, it is difficult for the photocatalyst and the adsorbent to remain in the sheet during wet papermaking, and when drainage is deteriorated, and sufficient deodorization is obtained. There may be no case. When the weight ratio ((C + D) / (A × B)) is larger than 2, the antifouling property is reduced, and the amount of the photocatalyst and the adsorbent remaining in the sheet may be reduced. Furthermore, even if a flame-retardant substance is used as a support-forming component in order to obtain a flame-retardant adsorptive photocatalyst sheet, sufficient flame retardancy cannot be obtained.

The support-forming component of the present invention is a component necessary for maintaining the form when forming the adsorptive photocatalyst sheet. As the support-forming component, synthetic resins, natural fibers, and the like can be used.

Examples of the synthetic resin used for the support-forming component include polyolefin resins such as polyethylene and polypropylene, polyester resins, polyvinyl acetate resins, ethylene vinyl acetate copolymer resins, polyamide resins such as nylon, and acrylic resins. , Polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl ether resin, polyvinyl ketone resin, polyether resin, polyvinyl alcohol resin, diene resin, thermoplastic synthetic resin such as polyurethane resin, phenol resin, melamine resin,
In addition to a thermosetting synthetic resin such as a furan resin, a urea resin, an aniline resin, an unsaturated polyester resin, an alkyd resin, and an epoxy resin, a silicon-based resin and a fluorine-based resin are included.

When these synthetic resins are used in the form of fibers, so-called synthetic resin fibers, their cross-sectional shapes are not particularly limited, and may be not only circular but also elliptical, triangular, star-shaped or T-shaped.
A so-called irregular cross-sectional shape such as a shape, a Y shape, and a leaf shape may be used. Further, those having voids on the fiber surface, those having a branched structure, and those having a core-sheath structure can also be used. Among these synthetic resin fibers, a core-sheath structure having a different softening point mainly from the viewpoint that the inter-fiber bond strength, flexibility (elasticity), workability and the like when used as a support or an adsorptive photocatalyst sheet can be appropriately controlled. Are preferred. Examples of the synthetic resin fiber having a core-sheath structure include a fiber whose core portion is made of polyester and a sheath portion made of a polyester copolymer, and a fiber whose core portion is made of polyester and whose sheath portion is made of polyolefin.

In particular, as the support-forming component according to the first invention, a so-called synthetic resin film in the form of a film can be used.

Examples of the natural fibers used as the support-forming component include chemical pulp such as kraft pulp, sulfite pulp, and alkali pulp from softwood and hardwood, semi-chemical pulp, thermomechanical pulp, mechanical pulp, and ground pulp. Examples include wood fiber, mulberry, mulberry, straw such as rice and wheat, hemp, kenaf, bamboo, cotton, cotton linter, bagasse, and vegetable non-wood fibers such as espart. These may be recycled pulp or deinked pulp made from waste paper.

The fibers other than the synthetic fiber resin and the natural fiber used for the support include regenerated fibers such as rayon, processed natural fibers such as cellulose derivative fibers, metal fibers such as steel wool and stainless steel wool, carbon fibers, and ceramic fibers. And various glass fibers.

Examples of the flame-retardant substance used as the support-forming component include inorganic substances such as essentially flame-retardant aramid resin, essentially non-flammable metal, glass, and oxides such as alumina.
Examples include composites in which a flame retardant is chemically incorporated into a synthetic resin, natural fiber, or the like, or physically blended. In particular, in the first invention, it is possible to use a support provided with flame retardancy by post-processing such as surface treatment with a flame retardant after forming the support.

Examples of the coagulant of the present invention include inorganic compounds such as alum and high molecular compounds such as polyacrylamide. Among them, electrolyte polymer compounds are preferable, and cationic electrolyte polymer compounds such as cationized polyacrylamide, cationized starch, and cationized guar gum are particularly preferable.

To produce the adsorptive photocatalyst sheet of the present invention comprising the photocatalyst, adsorbent, microbial cellulose and the support-forming component, a raw material mixture comprising the photocatalyst, adsorbent, microbial cellulose and the support-forming component is formed into a sheet. There is a method and a method in which a sheet-like support is formed in advance from the support-forming components, and then the support is mixed with a raw material mixture comprising a photocatalyst, an adsorbent, and microbial cellulose.

Specific examples of the method for producing an adsorptive photocatalyst sheet for forming a sheet of a raw material mixture comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component include photocatalysts,
Examples include a method of wet-papermaking an aqueous suspension comprising an adsorbent, microbial cellulose and a support-forming component, and a method of dry-papermaking a raw material comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component. Above all, a method for producing an adsorptive photocatalyst sheet by wet papermaking is preferred, and a production method for wet-papering an aqueous suspension further containing a coagulant, preferably a cationic electrolyte polymer compound, is particularly preferred.

For wet papermaking, a round paper machine, a fourdrinier paper machine,
Ford linear paper machines, twin wire paper machines, on-top paper machines, etc., and so-called combination formers combining a plurality of paper machines can be used. In addition, to prepare an aqueous suspension, the support-forming component is dispersed in an aqueous liquid in advance, and after treatment such as beating is performed as necessary, a photocatalyst, an adsorbent, microbial cellulose, and, if desired, a flocculant. And the like.

As a specific example of a method for producing an adsorptive photocatalyst sheet, a sheet-like support is formed in advance from the support-forming components, and the support contains a raw material mixture comprising a photocatalyst, an adsorbent and microbial cellulose. A method of applying an aqueous coating solution comprising a photocatalyst, an adsorbent, and microbial cellulose to a support such as a fibrous sheet or a film composed of a body-forming component may be used.

Examples of the coating method include impregnation in which a support such as a fibrous sheet is immersed in an aqueous coating solution, and application to the surface of a support such as a fibrous sheet and a film. As a method of impregnation and coating according to the present invention, a two-roll type conventional size press, a tab size press,
For gate roll size press, film transfer type size press, roll coater, air doctor coater, rod (bar) coater, blade coater, spray coater, gravure coater, micro gravure coater, die coater, and curtain coater And the like.

For coating such as impregnation and coating, glow discharge treatment, flame treatment, plasma treatment, electron beam irradiation treatment,
It is also a preferable method to coat the support after treating the surface of the support by ultraviolet irradiation treatment, ozone treatment or the like. These surface treatments may be used in combination of two or more methods, and different treatments may be performed on one surface and the other surface of the support. Since the coating may be performed on only one surface of the support, the surface treatment may be performed only on the coated surface.

In the adsorptive photocatalyst sheet of the present invention,
Microbial cellulose microscopically has fine ribbon-like fibers of several tens of nanometers forming a relatively coarse network structure, and has excellent photocatalytic adsorption properties. Since the photocatalyst held in the microbial cellulose is remarkably homogeneous, the photocatalyst held in the microbial cellulose is homogeneously dispersed in the support, and the photocatalyst that decomposes the contaminants even on the surface of the adsorptive photocatalyst sheet exists uniformly without uneven distribution. As a result, a remarkably excellent effect of removing contaminants, that is, a so-called antifouling effect can be obtained. Furthermore, the adsorptive photocatalyst sheet containing the microbial cellulose of the present invention unexpectedly has higher deodorizing performance than the conventional adsorptive photocatalyst sheet.

[0048]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto unless it exceeds the gist of the invention.

Preparation Example 1 Microbial cellulose was prepared by the following method. (1) Preparation of seed bacterial solution (growth of bacterial cells) Fructose 40 g / L, ammonium sulfate 3 g / L, potassium hydrogen phosphate 1.0 g / L, magnesium sulfate (MgSO _4.
7H ₂ O) 0.3g / L, bacto - peptone 5 g / L,
Acetobacter xylinum subspecies schlofermentans BPR2001 strain (FE) was placed in a 750 ml Roux flask filled with 100 ml of a basic medium having a composition of lactic acid 1.4 ml / L and an initial pH of 5.0.
1 ml of a cryopreserved bacterial solution of RM BP-4545) was inoculated and cultured at 28 ° C. for 3 days. After this seed culture,
After thoroughly shaking the Roux flask, the contents were subjected to gauze filtration under aseptic conditions to obtain a seed bacterial solution.

(2) Preparation of Microbial Cellulose by Stirring Culture Fructose 40 g / L, ammonium sulfate 3.3 g / L, potassium hydrogen phosphate 1.0 g / L, magnesium sulfate (MgSO 4)
_{4 · 7H 2 O) 0.25g /} L, corn steep liquor 40 g / L, vitamin mixture 10 g / L, and salts mixture sterile medium 540 a composition consisting of 10 g / L
ml jar fermenter (total volume 1)
000 ml) is aseptically inoculated with 60 ml of the above seed bacterial solution, and the pH is adjusted to 1N NaOH and 1N at 30 ° C. for 72 hours.
While adjusting to 5.0 using H ₂ SO ₄ , the stirring rotation speed was initially 400 rpm, and the dissolved oxygen was 3.0 to 21.
The mixture was stirred and cultured with a jar fermenter while controlling the number of revolutions so as to fall within 0%. Here, the above-mentioned vitamin mixture refers to inositol 200 mg / L, niacin 40
mg / L, hydridoxine hydrochloride 40 mg / L, thiamine hydrochloride 40 mg / L, calcium pantothenate 20 mg / L
L, lipoflavin 20 mg / L, p-aminobenzoic acid 2
0 mg / L, folic acid 0.2 mg / L, biotin 0.2 mg
/ L is the liquid composition consisting of, also, the above-mentioned salts _{mixture, FeSO 4 · 7H 2 O360mg /} L, CaCl 2
_{· 2H 2 O1470mg / L, Na} 2 MoO 2 · 2H 2 O2
_{42mg / L, ZnSO 4 · 7H} 2 O173mg / L, M
_{nSO 4 · 5H 2 O139mg / L} , CuSO 4 · 5H 2 O
This is a liquid having a composition of 5 mg / L.

After the cultivation, the solids in the jar fermenter were collected, washed with water, treated in a 1% aqueous NaOH solution at 110 ° C. for 20 minutes, and the resulting cellulose was washed with water until the washing solution became nearly neutral. To obtain microbial cellulose. Then, 200 times water based on the dry weight was added, and the mixture was defibrated at a maximum rotation speed (power frequency: 50 Hz) for 2 minutes using a blender (manufactured by Auster) to prepare a 0.5% suspension. And the microbial cellulose of Preparation Example 1.

Preliminary Operation 1 The photocatalyst / adsorbent retention index of the microbial cellulose of Preparation Example 1 was determined by the following method. Unbeaten LBKP to TA
For a total of 100 parts of the dry weight of the long fiber component of LBKP from which the fine fiber component was removed according to the sieving operation in the PPI standard method T261pm-79 "Fine fiber component of stock by wet screening" and the microbial cellulose of Preparation Example 1 The replacement amount of the microbial cellulose of Preparation Example 1 was
0, 1, 2, 4, and 8 parts were changed to 5 levels, and 50 parts of titanium oxide (manufactured by Ishihara Sangyo, ST-31) and a silicate-based inorganic adsorbent (Mizukanite AP, manufactured by Mizusawa Chemicals) were used. 50
And 0.5 part of a cationized polyacrylamide (manufactured by Allied Colloids, Percoll 57) was added to adjust 500 ml of a 0.5% aqueous suspension.
The retained amount of titanium oxide and inorganic adsorbent and the retained amount of microbial cellulose were determined based on the retention operation in the standard method T261pm-79 "fine fiber content of stock by wet screening". The screen used a 100-mesh wire mesh, and the rotation speed of the dynamic drainage jar was set to 500 rpm.
As a result of this test, when the replacement amount of microbial cellulose was 2 parts, the correction value of the amount of microbial cellulose retained was 0.8
8 parts, the remaining amount of titanium oxide and inorganic adsorbent is 23.9
In addition, when microbial cellulose was not added (substitution amount was 0 part), the amount of the retained titanium oxide and inorganic adsorbent was 10.1 parts.
Department. Therefore, cationized polyacrylamide (manufactured by Allied Colloid Co., Percoll 57) is used as a flocculant.
The photocatalyst / adsorbent retention index of the microbial cellulose of Preparation Example 1 when an appropriate amount of was added was 15.7. In addition, the correction value of the amount of microbial cellulose retained was plotted with the amount of microbial cellulose retained against 0, 1, 2, 4, and 8 parts of the replacement amount of microbial cellulose. The remaining amount of microbial cellulose in 2 parts of the replacement amount of cellulose was determined.

Preliminary operation 2 The test was performed in the same manner as in Preliminary operation 1 except that 0.5 parts of cationized polyacrylamide (manufactured by Allied Colloids, Percoll 57) was not added. As a result of this test, when the replacement amount of microbial cellulose was 4 parts, the correction value of the amount of microbial cellulose retained was 1.67 parts, the amount of retained titanium oxide and inorganic adsorbent was 26.2 parts, When microbial cellulose was not added (substitution amount was 0 part), the amount of the retained titanium oxide and inorganic adsorbent was 9.0 parts. Therefore, the photocatalyst / adsorbent retention index of the microbial cellulose of Preparation Example 1 in the case where the coagulant is not used together is 10.3.

Preparation Example 2 Microbial cellulose was prepared by the following method. Sucrose 50 g / L, yeast extract 5 g / L, ammonium sulfate 5 g / L, potassium hydrogen phosphate 3 g / L, magnesium sulfate (MgS
O ₄ · 7H ₂ O) medium composition consisting of 0.5 g / L (pH
5.0) 50 ml was placed in a 200 ml Erlenmeyer flask, and sterilized with steam at 120 ° C. for 20 minutes to prepare a culture solution. Next, Acetobacter xylinum (30 ml) grown on a test tube slant agar medium (pH 6.0) composed of 5 g / L of yeast extract, 3 g / L of peptone, and 25 g / L of mannitol in this culture solution at 30 ° C. ATCC 108
21) was inoculated one loop at a time and cultured at 30 ° C. for 30 days. As a result, a gel-like film containing white microbial cellulosic polysaccharide was formed on the upper layer of the culture solution. After washing this gel-like film with water, it is heated in a 1% NaOH aqueous solution at 110 ° C. for 30 minutes.
For a minute, and the resulting cellulose was washed with water until the washing solution was near neutral to obtain microbial cellulose. Next, water 200 times the dry weight was added, and the maximum number of revolutions (power frequency: 50 Hz) was performed using a blender (Auster).
For 3 minutes to prepare a 0.5% suspension, which was designated as Microbial Cellulose of Preparation Example 2.

Preliminary operation 3 The test was carried out in the same manner as in Preparative operation 1, except that the microbial cellulose of Preparative example 1 was replaced with the microbial cellulose of Preparative example 2. As a result of this test,
When the replacement amount of microbial cellulose was 4 parts, the correction value of the amount of microbial cellulose retained was 3.80 parts, the amount of retained titanium oxide and inorganic adsorbent was 43.9 parts, and no microbial cellulose was added ( When the substitution amount was 0 part), the remaining amount of the titanium oxide and the inorganic adsorbent was 10.1 parts. Therefore, the photocatalyst / adsorbent retention index of the microbial cellulose of Preparation Example 2 when an appropriate amount of cationized polyacrylamide (Percoll 57, manufactured by Allied Colloids Co., Ltd.) was added as an aggregating agent was 8.9.

Preparation Example 3 75% by weight of vinyl chloride-vinyl acetate copolymer fiber (manufactured by Mitsubishi Rayon Co., Ltd., VF, fineness: 3 denier, fiber length: 6 mm) as a support-forming component, and a heat-fusible polyester fiber (Unitika) as a binder fiber Made by Melty 408
An aqueous slurry was prepared by adding and mixing 25% by weight of water, 0 denier, 2 denier, and fiber length of 5 mm) in water to prepare a flame-retardant support having a basis weight of 50 g / m ² using a circular web paper machine.

Example 1 Smecton SA manufactured by Kunimine Industries was dispersed in water, and titanium oxide (P25, manufactured by Nippon Aerosil Co., Ltd.) was added thereto as a photocatalyst.
S6) A silicate-based inorganic adsorbent (Mizukanite AP, manufactured by Mizusawa Kagaku) and the microbial cellulose of Preparation Example 1 were mixed as the adsorbent so that the solid content ratio was 1: 3: 2: 2. A coating liquid is prepared, and the coating amount of this coating liquid is 10% by dry weight.
g / m ² was impregnated with the flame-retardant support of Preparation Example 3, and dried with a cylindrical dryer to obtain the adsorptive photocatalyst sheet of Example 1.

Example 2 The microbial cellulose of Preparation Example 1 and unbeaten LBKP previously dispersed in water as a support-forming component were mixed in a weight ratio of 1:99.
23.5 parts of titanium oxide (manufactured by Ishihara Sangyo, ST-31) as a photocatalyst and 100 parts of a raw material mixed with a silicate-based inorganic adsorbent (Mizukanite AP, manufactured by Mizusawa Chemical) as an adsorbent. An aqueous suspension was prepared by adding 5 parts and 0.25 part of cationized polyacrylamide (manufactured by Allied Colloids, Percoll 57) as a flocculant, and prepared a standard square hand-made sheet machine (manufactured by Kumagaya Riki Kogyo Co., Ltd.). ) At basis weight 6
A sheet of 0 g / m ² was made and dried with a cylindrical dryer to obtain the adsorptive photocatalyst sheet of Example 2.

Examples 3 to 7 In Example 2, microbial cellulose and unbeaten LBK were used.
1.5: 98.5 instead of 1:99 by weight of P, 3:
Except that 100 parts of the raw materials were mixed at 97, 6:94, 8:92, and 10:90, an adsorptive photocatalyst sheet was produced in the same manner as in Example 2 in all cases. These samples are
The adsorptive photocatalyst sheets of Example 3, Example 4, Example 5, Example 6, and Example 7 were obtained in ascending order of the mixing ratio of the microbial cellulose.

Example 8 The procedure of Example 2 was repeated except that the flocculant was not added and the weight ratio of microbial cellulose to unbeaten LBKP was changed to 1:99.
An adsorbent photocatalyst sheet was produced in the same manner as in Example 2 except that 100 parts of the raw materials were mixed at 5: 95.5. This sample was used as the adsorptive photocatalyst sheet of Example 8.

Example 9 In Example 2, the microbial cellulose of Preparation Example 2 was replaced with the microbial cellulose of Preparation Example 1, and the weight ratio of the microbial cellulose and unbeaten LBKP was mixed at 5:95 instead of 1:99. An adsorptive photocatalyst sheet was produced in the same manner as in Example 2 except that 100 parts of the raw material were used. This sample was used as the adsorptive photocatalyst sheet of Example 9.

Examples 10 and 11 In Examples 3 and 4, instead of unbeaten LBKP,
Except for using vinyl chloride-vinyl acetate copolymer fiber (manufactured by Mitsubishi Rayon Co., Ltd., VF, fineness: 3 denier, fiber length: 6 mm), an adsorptive photocatalyst sheet was produced in the same manner as in Examples 3 and 4. These samples were prepared in the order of Examples 10 and 11 in ascending order of mixing ratio of microbial cellulose.
Of the adsorbent photocatalyst sheet.

Comparative Example 1 In Example 1, microfibrillated cellulose (Seris KY-10, manufactured by Daicel Industries Ltd.) was used instead of microbial cellulose.
An adsorptive photocatalyst sheet was produced in the same manner as in Example 1 except that 0S) was used. This sample was used as the adsorptive photocatalyst sheet of Comparative Example 1.

Comparative Example 2 In Example 2, microfibrillated cellulose (Seris KY-10, manufactured by Daicel Industries Ltd.) was used instead of microbial cellulose.
An adsorptive photocatalyst sheet was produced in the same manner as in Example 2 except that 0S) was used. This sample was used as the adsorptive photocatalyst sheet of Comparative Example 2.

Comparative Examples 3 to 7 In Examples 3 to 7, microfibrillated cellulose (manufactured by Daicel Industries, Cellish KY-) was used in place of microbial cellulose.
Except for 100S), an adsorptive photocatalyst sheet was produced in the same manner as in Example 2 in all cases. These samples were prepared in the order of Comparative Example 3, Comparative Example 4, Comparative Example 5, Comparative Example 6, and Comparative Example 7 in ascending order of mixing ratio of microfibrillated cellulose.
Was obtained as an adsorptive photocatalyst sheet.

Comparative Example 8 In Comparative Example 7, a vinyl chloride-vinyl acetate copolymer fiber (manufactured by Mitsubishi Rayon Co., Ltd.) was used instead of unbeaten LBKP.
F, a fineness of 3 denier and a fiber length of 6 mm), except that an adsorptive photocatalyst sheet was produced in the same manner as in Comparative Example 7. This sample was used as the adsorptive photocatalyst sheet of Comparative Example 8.

The adsorptive photocatalyst sheets obtained in Examples and Comparative Examples were tested by the following methods, and the results are shown in Table 1.

[Stain resistance] The stain resistance test was conducted as follows. First, the color difference of the adsorptive photocatalyst sheet before the antifouling test was measured with a color difference meter (Lab type, manufactured by Minolta). Next, the adsorptive photocatalyst sheets of Examples and Comparative Examples were placed one by one in a 0.1 m ³ closed container, and smoke for 10 cigarettes (mild seven) was introduced into the container using a pump. Next, the adsorptive photocatalyst sheet is taken out, and the color difference of the adsorptive photocatalyst sheet immediately after the introduction of tobacco smoke is measured by a color difference meter. Then, the adsorptive photocatalyst sheet is returned to the container, the lighting device is set in the container, and the fluorescent lamp is turned on. The color difference of the adsorbable photocatalyst sheet after lighting for a while and after lighting was measured by a color difference meter. The antifouling property was determined based on the fluctuation of the b value indicating yellowish among the measured values of the color difference meter of each adsorptive photocatalyst sheet. That is, the b value of the adsorptive photocatalyst sheet before the antifouling test was b0, the b value of the adsorptive photocatalyst sheet immediately after the introduction of tobacco smoke was b1, and the b value of the adsorptive photocatalyst sheet after lighting for 50 hours with the fluorescent lamp was b2. , B0 to b1, the degree of contamination load removed at b2 is shown as a percentage. When the value is 0%, it indicates that the pollution load has not been reduced at all, and 100%
Shows a state in which the pollution load has been completely removed.

[Deodorizing Property] Each of the adsorptive photocatalyst sheets of Examples and Comparative Examples was placed in a 0.1 m ³ closed container, and smoke for 10 cigarettes (mild seven) was introduced using a pump. Thereafter, the fluorescent lamp was turned on. Immediately after the introduction of cigarette smoke, the concentration of acetaldehyde (one of the main components of tobacco odor) in the container was measured by gas chromatography, and the amount of acetaldehyde decreased after 10 minutes was measured using a blank (a fluorescent lamp without an adsorbent photocatalyst sheet attached). 10 minutes after lighting), when the amount of acetaldehyde decrease is more than 5 times, the deodorizing property is excellent, and when 2 to 5 times, the deodorizing property is good, and when it is less than 2 times and 1 time or more, The case where the deodorizing property was average and smaller than 1 time was judged to be inferior in the deodorizing property.

[Fixation rate of photocatalyst] Except for the adsorptive photocatalyst sheet whose support-forming component is a flame-retardant substance, the ash content of the adsorptive photocatalyst sheet was determined by the ash test of paper and paperboard described in JIS-P-8128. 500 ° C using an electric furnace according to
And then incinerated and measured. In addition, a part of the aqueous suspension before forming the adsorptive photocatalyst sheet was filtered using a filter paper for quantitative analysis and dried, and the ash content was measured in the same manner as in the adsorptive photocatalyst sheet. Since the adsorptive photocatalyst sheets in Examples and Comparative Examples have a small content of inorganic components other than the photocatalyst and the adsorbent, the ash represents the content of the adsorptive photocatalyst sheet and the photocatalyst in the aqueous suspension. . Therefore, from the ash content (H%) of the adsorptive photocatalyst sheet and the ash content (I%) of the aqueous suspension filtrate, the fixing rate of the photocatalyst during the production of the adsorptive photocatalyst sheet ( J) was determined.

[0071]

## EQU2 ## J (%) = 100 × {H / (100−H)} /
{I / (100-I)}

[Workability] The adsorptive photocatalyst sheets of the examples and comparative examples were folded 180 degrees so that the same side surfaces were in contact with each other and creased. The bending operation was performed once, and after this bending was performed 10 times, a commercially available cellophane adhesive tape was applied to the inside of the first folded side, the so-called valley fold side, and adhered to the tape when this was peeled off. The degree of dirt was observed. The processability of the adsorptive photocatalyst sheet is excellent when there is no dirt, good when slightly dirt,
Those that were stained normally were judged as average, and those that were markedly stained were judged as inferior.

[Flame Retardancy] With respect to an adsorptive photocatalyst sheet whose support-forming component is a flame retardant substance, JIS-L-109
Flame retardancy was tested according to Method A-1 of 1. Category 3 is
It is required when high flame retardancy is particularly required, for example, when the flame after flame satisfies items such as after-flame time of 3 seconds or less and flammable materials that may cause fire are not approached. Category 2 is a level that satisfies items such as 3 seconds after flame arrival and 10 seconds or less afterflame, and is required when ordinary flame retardancy is required. 1 is a level that has low flame retardancy and cannot be used when there is a risk of heating or flame.

Table 1 shows the results of the above test items.

[0075]

[Table 1]

The photocatalytic adsorbent weight ratio in the table means the amount of photocatalyst added (C) and the amount of adsorbent added to the product of the photocatalyst / adsorbent retention index (A) of microbial cellulose and the added amount (B) of microbial cellulose. Weight (D) and the total weight ratio ((C
+ D) / (A × B)). In the present invention, 0.5 to 2
It is preferred that

[0077]

As described above, the adsorptive photocatalyst sheet of the present invention is an adsorptive photocatalyst sheet comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component, or a photocatalyst, an adsorbent, microbial cellulose and a support-forming material. An adsorptive photocatalyst sheet obtained by wet-making an aqueous suspension composed of components, which has excellent decomposability of harmful substances such as odorous substances and dirt substances, and has excellent post-processing properties of the sheet. Since it has excellent deodorizing properties, it is highly useful as a filter member for air purifiers for in-vehicle and household use, which have recently been required to be reduced in size and thickness. In particular, in an adsorptive photocatalyst sheet obtained by wet-making an aqueous suspension comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component, the aqueous suspension preferably further contains a flocculant, and the photocatalyst and An object of the present invention is to provide an adsorptive photocatalyst sheet which is more excellent in the fixation rate of an adsorbent and post-processability. In addition, a photocatalyst,
In an adsorptive photocatalyst sheet obtained by wet-making an aqueous suspension comprising an adsorbent, microbial cellulose and a support-forming component, preferably an aqueous suspension further containing a flocculant, the photocatalyst / adsorbent retention of microbial cellulose Indicator (A)
The total weight ratio ((C + D) / (A × B)) of the addition amount (C) of the photocatalyst and the addition amount (D) of the adsorbent to the product of the addition amount (B) of the microbial cellulose is 0.5 to It is preferred to be in the range of 2. In other words, if the weight ratio is less than 0.5, the fixation rate and post-processability of the photocatalyst and the adsorbent are reduced. And the antifouling property is clearly reduced. On the other hand, in the adsorptive photocatalyst sheet of the present invention, microbial cellulose is preferably a cellulosic substance produced by a stirring culture method, and provides an adsorptive photocatalyst sheet with particularly excellent antifouling properties. Further, the adsorptive photocatalyst sheet of the present invention, wherein the support-forming component is a flame-retardant substance, is characterized in that, in addition to the decomposability of harmful substances and the post-processability of the sheet, microbial cellulose is used for the photocatalyst and adsorbent Because of its excellent retentivity,
The content of a flammable cellulosic substance can be suppressed to an extremely small amount, and an adsorptive photocatalyst sheet excellent in flame retardancy is provided. It can be used in close proximity to the contacts of electrical equipment such as a photocatalyst excitation light source, and a light source or a blower that may cause discharge ignition, and is highly useful as a filter member of an air purifier, for example. .

Claims (6)

[Claims] 1. An adsorptive photocatalyst sheet comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component. 2. An adsorptive photocatalyst sheet obtained by wet-making an aqueous suspension comprising a photocatalyst, an adsorbent, microbial cellulose and a support-forming component. 3. The adsorptive photocatalyst sheet according to claim 2, wherein the aqueous suspension further contains a flocculant. 4. The total weight of the photocatalyst addition amount (C) and the adsorbent addition amount (D) based on the product of the photocatalyst / adsorbent retention index (A) of microbial cellulose and the addition amount (B) of microbial cellulose. The ratio ((C + D) / (A × B)) is 0.5 to
4. The adsorptive photocatalyst sheet according to claim 2, wherein 5. The adsorptive photocatalyst sheet according to claim 1, wherein the microbial cellulose is a cellulosic substance produced by a stirring culture method. 6. The adsorptive photocatalyst sheet according to claim 1, wherein the support-forming component is a flame-retardant substance.