JP2006124260A - Water-permeable flat board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-permeable flat board capable of being efficiently manufactured while securing contradictory properties such as high bending strength and high water permeability, and to provide its manufacturing method. <P>SOLUTION: The water-permeable flat board includes a water-permeable surface layer formed by joining aggregate having 1-10 mm particle diameter and uniformity coefficient of <4 to each other with cement in which a polymer thickener is mixed as a main binder and a base part layer formed by joining the aggregate having 1-10 mm particle diameter and uniformity coefficient of <4 to each other with the cement in which the polymer thickener is mixed as a main binder. The water-permeable flat board is manufactured by joining the surface layer and the base part layer with each other using the cement in which the polymer thickener is mixed as the binder and has ≥0.1 cm/sec water permeability and ≥4 MPa bending strength. The water-permeable flat board is obtained by successively carrying out a step (10) for filling a block material for the base part layer by applying vibration, a mold clamping step (20), a step (30) for filling a block material for the surface layer and a molding step (40). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transparent horizontal plate having excellent water permeability and high bending strength, and a method for producing the same.

  Conventionally, a transparent horizontal plate has been widely used as a pavement material for pedestrian roads and the like because rainwater quickly moves in the block during rain and hardly causes a puddle on the block surface.

  Among such transparent horizontal plates, an interlocking block (trade name) is commercially available as a concrete product for paving for pedestrian roads. And in this interlocking quality standard, the bending strength is 3.0 MPa or more and the water permeability is 0.01 cm / second or more (see, for example, Patent Document 1).

  Generally, in a water-permeable pavement material, the higher the bending strength, the better, and the larger the water permeability coefficient is preferred, but if you want to improve the water permeability, you have to take a more porous structure, strength However, when trying to improve the strength, the structure of the block has to be densified, and the water permeability tends to decrease (see, for example, Patent Document 2).

  For example, it is known that if the particle diameter of the aggregate is reduced, the bending strength is increased. However, when the bending strength is increased, the water permeability is decreased (for example, see Patent Document 3). .

  In addition, it is known that if a polymer binder is added to cement, the bending strength is increased. However, it is pointed out that the water permeability is greatly reduced when the amount is increased (for example, see Patent Document 4). ).

  The present applicant has already proposed a method for producing such a transparent horizontal plate having excellent bending strength and water permeability by an original method (see, for example, Patent Document 5).

  The transparent horizontal plate by this method is, for example, mixed with the surface layer block material and the lower layer block material separately, put in the order of the surface layer block material and the lower layer block material, and then vibrated by the mold clamping machine Molded by compaction. The clamped block is demolded immediately or after curing in the room all day and night. A transparent horizontal plate having a two-layer structure having a surface layer with a good appearance is prepared by polishing the surface after curing of the cement.

In addition, when a NOx removal catalyst that functions as a photocatalyst is held on the surface of such a transparent horizontal plate, a titanium oxide slurry is mixed in a binder to produce a transparent horizontal plate, or obtained. The titanium oxide slurry was sprayed on the surface of the obtained transparent horizontal plate, and the titanium oxide slurry was adhered between the aggregates by natural drying or the like (see, for example, Patent Document 6).
JP 2003-206504 A JP 2001-342055 A JP 2001-182003 A (0015 paragraph) Japanese Patent Publication No. 47-7-99902 (right column on page 2) JP-A-5-24955 (Example and FIG. 2) JP 2001-90004 A (Example 1 and Example 2).

  In recent years, in consideration of the environment, a transparent horizontal plate has been adopted in various situations, and it has been desired to provide an inexpensive transparent horizontal plate having high bending strength and high water permeability.

  Furthermore, it is desirable that the transparent horizontal plate used facing the roadway is provided with a catalytic function for removing NOx that functions as a photocatalyst, and the transparent horizontal plate provided with such a photocatalytic function also has a high bending rate. In addition to the strength and high water permeability, it is required that the production efficiency of the transparent horizontal plate is increased.

  When producing a transparent horizontal plate using a binder containing a photocatalyst, no special process is required except for the process for mixing the photocatalyst into the binder, so the production efficiency will not be significantly reduced. The ratio of the photocatalyst exposed on the surface of the transparent horizontal plate is extremely small, and in order to impart practical photocatalytic performance, a large amount of photocatalyst is required, and there is a problem that the price is high.

  In contrast, a method in which titanium oxide slurry is sprayed on the surface of the obtained transparent horizontal plate and the titanium oxide slurry is adhered between aggregates by natural drying or the like can achieve a high photocatalytic function by using a small amount of photocatalyst. However, in order to give a photocatalytic function, there is a problem that two additional steps of applying a catalyst and a drying step are necessary.

  In addition, the titanium oxide powder is formed from particulate titanium oxide, but it is very fine particles, and the technology for producing a stable dispersion (titanium oxide slurry) is advanced, which increases the production cost. Or, when a stable dispersion is not used, it may be difficult to form a dense titanium oxide film having excellent adhesion.

  Accordingly, a first object of the present invention is to provide a transparent horizontal plate that can be manufactured more efficiently while ensuring the contradictory properties of increased bending strength and water permeability, and a method for manufacturing the same.

  Another object of the present invention is to reduce the production efficiency even when the NOx removal catalyst that functions as a photocatalyst is applied to the transparent horizontal plate in the transparent horizontal plate that can solve the first object and the manufacturing method thereof. It is another object to provide a transparent horizontal plate and a method for producing the same that can reliably exhibit a photocatalytic function by using a small amount of photocatalyst.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have found a molding apparatus having a clamping function and a vibration function for producing a concrete block product, and a cement mixed with a polymer thickener. Using the block material for the surface layer and the base layer as the main binder, filling the base layer block material into the mold while applying vibration by a molding device, and then clamping the mold, then applying the vibration to the surface layer in the mold By using a method of processing the surface of the surface part of the molded product that has been demolded using a wet polishing machine and an ultra-high pressure processing machine, the bending strength and water permeability can be increased. It has been found that a permeable horizontal plate can be produced efficiently because a water-permeable surface layer can be directly molded without forming a water-impermeable layer on the product surface while ensuring the contradictory property of rising.

  Moreover, according to such a manufacturing method, if a catalyst for removing NOx that functions as a photocatalyst is sprayed at an appropriate stage after mold clamping and before demolding, the curing process and the drying process can be used together. Can reduce the amount of photocatalyst used because it can be deposited near the surface, and the photocatalyst can easily adhere to uncured cement components. It was found that a flat plate was obtained.

  That is, the present invention uses a cement mixed with a polymer thickener as a main binder, and has a water-permeable surface layer in which aggregates having a particle diameter within a range of 1 mm to 10 mm and having a uniformity coefficient of less than 4 are joined together, Cement mixed with a polymer thickener as a main binder includes a base layer having a particle diameter in the range of 1 mm to 10 mm and an aggregate having a uniformity coefficient of less than 4, and a surface layer and a base layer. Is a permeable horizontal plate characterized in that cement containing a polymer thickener is bonded as a main binder, the water permeability is 0.1 cm / second or more, and the bending strength is 4 MPa or more.

  Such a transparent horizontal plate uses, for example, a surface layer block material and a base layer block material, and a base layer block material filling step for filling the base layer block material in a mold while applying vibrations. Mold clamping process in which compressive force is applied to the filling while compacting, and surface layer block material filling process in which the block material for surface layer is filled in the mold while giving vibration immediately after the mold clamping process, immediately after the filling process Permeability is achieved by sequentially performing the molding process of molding by applying compressive force to the filling while applying vibration, and then combining the demolding process of demolding the molded article from the mold and the curing process of curing the molded article. A flat plate can be obtained.

  Here, the surface block material is cement (C) mixed with a polymer thickener, and water (W) having a mass ratio (W / C) within the range of 0.20 to 0.35 with respect to the total mass of the cement C. And the particle diameter is in the range of 1 mm to 10 mm, and the surface layer aggregate has a uniformity coefficient of less than 4. The block material for the base layer is cement (C) mixed with a polymer thickener, and water (W) having a mass ratio (W / C) within the range of 0.20 to 0.35 with respect to the total mass of the cement C. And a base layer aggregate having a particle diameter in the range of 1 mm to 10 mm and a uniformity coefficient of less than 4.

The base layer block material filling step is preferably performed under the condition of a motor frequency in the range of 3000 revolutions / minute to 4000 revolutions / minute, with a material supply time in the range of 1 second to 3 seconds. The mold clamping process is performed at a clamping frequency within the range of 15 kg / cm ^{2 to} 50 kg / cm ² at a motor frequency within the range of 1500 rpm / minute to 2000 rpm / minute for 0.1 seconds to 1 second. It is preferable to perform time clamping within the range. Moreover, it is preferable that the block material filling process for the surface layer is performed under the condition of the motor frequency within the range of 3000 rpm / minute to 4000 rpm / minute, with the material supply time within the range of 1 second to 3 seconds. Further, the molding process is performed within a range of 2 seconds to 5 seconds at a motor frequency within a range of 1500 rpm to 2000 rpm with a clamping pressure within a range of 15 kg / cm ^{2 to} 50 kg / cm ² . It is preferable that the time is clamped.

  Moreover, it is preferable that the binder contains an anti-whitening agent, and the polymer thickener is an acrylic resin. Moreover, as a white-fade prevention agent in this case, a fatty acid anionic surfactant is preferable, for example. The fatty acid anionic surfactant can maintain the thickening effect of the acrylic resin.

  Further, it is preferable that titanium oxide as a NOx removal catalyst is fixed to the surface side of the surface layer binder constituting the surface layer. Such fixation is obtained by performing curing after performing a titanium oxide application step for applying titanium oxide that functions as a photocatalyst from the surface side after the molding step and before the curing step.

  Thus, the titanium oxide provided at the stage before curing can be fixed to the cement material in the curing process.

  Further, in the present invention, such a thin layer of titanium oxide catalyst is applied at an appropriate stage after the curing step, so that a thin layer mainly composed of titanium oxide as a NOx removal catalyst is formed on the surface thereof. Can be granted.

  Such a titanium oxide provision process can be performed by, for example, applying a predetermined amount of slurry containing titanium oxide by spraying or the like.

  Here, in the present invention, instead of the slurry containing titanium oxide, a peroxotitanate ion aqueous solution is used, or a titanium oxide film that functions as a photocatalyst by applying a hydrogen peroxide solution after applying a titanium salt aqueous solution is used. A film may be formed. This allows the peroxotitanate ion aqueous solution to form a titanium oxide film in response to the alkalinity of the cement before the curing process, and also reacts with the alkalinity of the titanium salt aqueous solution possessed by the cement before the curing process. However, a titanium oxide film that functions as a photocatalyst by reacting with hydrogen peroxide solution can be formed.

  In any case, since the obtained titanium oxide film is fixed to the surface side of the transparent horizontal plate, the titanium oxide as the NOx removal catalyst is not caused to flow by repeated rainfall and sunshine, and for a long time. Thus, the photocatalytic effect can be maintained.

  Further, the surface layer preferably has a thin layer mainly composed of titanium oxide as a NOx removal catalyst on the surface thereof.

  Further, in the present invention, such a thin layer of titanium oxide catalyst is applied at an appropriate stage after the curing step, so that a thin layer mainly composed of titanium oxide as a NOx removal catalyst is formed on the surface thereof. It can be applied or titanium oxide can be fixed.

  For example, at an appropriate stage after the curing process, a thin layer of titanium oxide can be applied to the surface layer by spraying a slurry containing titanium oxide as a NOx removal catalyst that functions as a photocatalyst from the surface side by spraying or the like. .

  Instead of slurry containing titanium oxide, a peroxotitanate ion aqueous solution is used in the presence of alkali, or a titanium oxide aqueous solution is added to form a titanium oxide film that functions as a photocatalyst. A film may be formed. In either case, the alkali and peroxotitanate ions react to form a titanium oxide film on the surface of the block. The alkali in this case can be additionally provided when the alkali of the block is insufficient. The addition of alkali to be added may be applied at any stage as long as it can work with the titanium oxide film forming solution. However, since the block has a high affinity for alkali, the alkali applied to the block is not limited. Is easily dispersed uniformly on the surface, and this makes it possible to form a titanium oxide film that is highly dispersed and difficult to fall off when a titanium oxide film-forming solution is applied later.

  In any case, after the curing process, a thin layer of cement as a binder is obtained on the surface of the aggregate having irregularities on the surface layer side. By applying a slurry containing titanium oxide to the cement thin layer, a small amount of titanium oxide is allowed to act on the cement thin layer, thereby providing a thin layer of titanium oxide exposed to the outside on the aggregate surface. As a result, the photocatalytic function can be maximized.

  The NOx removal catalyst having such performance is preferably titanium oxide having an average particle size of 40 nm or less and a main crystal structure of anatase type.

  Thus, according to the present invention, it is possible to provide a transparent horizontal plate and a method for manufacturing the same that can reliably exhibit the photocatalytic function without lowering the production efficiency and using a small amount of the photocatalyst.

  According to the present invention, it is possible to provide a transparent horizontal plate and a method for manufacturing the same that can be manufactured more efficiently while ensuring the contradictory properties of bending strength and water permeability.

  Further, according to the present invention, even when a NOx removal catalyst that functions as a photocatalyst is applied to the permeable horizontal plate, the water permeable property that can reliably exhibit the photocatalytic function by using a small amount of photocatalyst without reducing the production efficiency. A flat plate and a manufacturing method thereof can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described.

  First, the transparent horizontal plate according to the present invention has a particle diameter in a range of 1 mm to 10 mm, a surface layer in which aggregates having a uniformity coefficient of less than 4 are joined, and a particle diameter in a range of 1 mm to 10 mm. And a base layer in which aggregates having a uniformity coefficient of less than 4 are joined together. As a binder for bonding the aggregates of the surface layer and the base layer, a cement mixed with a polymer thickener is used as a main component. The surface layer and the base layer are joined by using cement containing a polymer thickener as a main binder. The water permeability of the permeable horizontal plate obtained by this is 0.1 cm / second or more, and the bending strength is 4 MPa or more.

  Such a transparent horizontal plate is manufactured using, for example, a surface layer block material and a base layer block material. For example, as shown in FIG. 1, a base layer block material filling step (10) in which a base layer block material is filled in a mold while applying vibration, and a compressive force is applied to the filling while applying vibration immediately after filling. Mold clamping step (20) for compaction, surface block material filling step (30) for filling surface layer block material into the mold while applying vibration immediately after mold clamping step (20), filling step (30) Immediately after that, a molding step (40) is performed in which a compressive force is applied to the filler while vibration is applied.

Thereafter, as shown in FIGS. 2 to 5, a demolding step (50) for demolding the molded product from the mold, a curing step (60) for curing the molded product, and a surface for treating the surface of the molded product as necessary. A transparent horizontal plate can be obtained by appropriately combining the processing steps (70).
[Block material for surface layer]
Next, each material used in the present invention will be described.

The surface layer block material used in the present invention is cement C mixed with a polymer thickener, water having a mass ratio (W / C) to the total mass of cement C in the range of 0.20 to 0.35 ( W) and a particle diameter in a range of 1 mm to 10 mm, and an aggregate for a surface layer having a uniformity coefficient of less than 4.
[Block material for base layer]
The base layer block material used in the present invention is cement C mixed with a polymer thickener, water having a mass ratio (W / C) to the total mass of cement C in the range of 0.20 to 0.35. (W) and a particle diameter within a range of 1 mm to 10 mm, and a base layer aggregate having a uniformity coefficient of less than 4.
[Thickener]
As the polymer thickener used in the present invention, any thickener for cement blends can be used. For example, as the thickener, cellulose derivatives, polysaccharides, polyacrylamide, polyethylene oxide, polyvinyl ether, water-soluble polyurethane, and the like can be used. Moreover, the shape is also free, such as powder form and latex form.

  When kneading a thickener in a cement formulation, if the thickener is a powder, so-called mamako may be formed by contact with water. It is advisable to take measures to prevent the formation of mamako by dispersing the thickener well, and then knead by adding water.

  Here, in consideration of compatibility when a thickener is used in combination with an efflorescence inhibitor (white flower inhibitor), an acrylic (acrylic resin) thickener is a fatty acid anionic surfactant-based white. Even if used in combination with an anti-fading agent, the thickening effect can be maintained, and the high bending strength of the obtained transparent horizontal plate can be maintained, which is preferable.

  Examples of such an acrylic resin-based thickener include sodium polyacrylate, polyacrylamide, sulfonated polyacrylamide, etc., but preferably a polymer mainly composed of acrylic ester, methacrylic ester, styrene or the like. Latex. Synthetic polymer latex obtained by emulsion polymerization of acrylic monomers can be used by blending it into cement paste by a mixing method.

  Binders added with acrylic thickeners are easy to knead because there is no agglomeration of raw materials during kneading, and the viscosity increases, and even if a small amount of binder is used, the aggregates can be firmly bonded to each other. Can do. Thereby, the water permeability of the obtained permeable horizontal board increases, and improvement of bending strength can be aimed at.

  The addition amount of the thickener used in the present invention varies depending on the type of monomer constituting the thickener, the intrinsic viscosity, the type of cement, the type of other admixtures, etc., but is generally 0 with respect to the cement mass. It is preferable to be within the range of 0.01% to 3.0%. If the amount of the thickener is too small, the required viscosity cannot be imparted to the cement as the binder. If the amount of the thickener is too large, the viscosity is too high, the fluidity is poor, and the filling becomes difficult. The preferred amount of thickener is in the range of 0.01% to 3.0% with respect to the cement mass.

  In the present invention, when an acrylic thickener is added, a premixed acrylic thickener (premix polymer cement paste: so-called maintenance paste) may be used, or an aqueous solution may be added. .

At this time, an appropriate amount of various film forming assistants such as alkyl alcohol and ester can be added. In addition, for example, a carboxylic acid polymer, a formaldehyde condensate of β-alkylnaphthalenesulfonic acid, a formaldehyde condensate of melamine sulfonic acid, a formaldehyde condensate of β-alkylnaphthalenesulfonic acid / ligninsulfonic acid, and a β-alkylanthracenesulfonic acid An appropriate amount of a high-performance water reducing agent such as a formaldehyde condensate can also be added. Moreover, suitable amounts of a dispersant for concrete and a fluidizing agent can be added.
[cement]
Examples of the cement used in the present invention include Portland cement (ordinary Portland cement, early-strength Portland cement, moderately-heated Portland cement, white Portland cement, and ultra-early strong Portland cement), and mixed cement (blast furnace cement, silica cement, fly ash cement). ), A special cement (alumina cement, expanded cement) or the like.

However, in the present invention, a special cement is not always necessary, and an inexpensive and easily available cement can be used. They are, for example, Portland cement, blast furnace cement, fly ash cement, and the like, and sufficient characteristics can be obtained even when such versatile cement is used.
[aggregate]
Further, the aggregate used in the present invention is not particularly limited as long as it is suitable for a transparent horizontal plate having a high bending strength, but it is essentially important that the particle diameter is in the range of 1 mm to 10 mm. is there. If the particle size is too small, it is difficult to exhibit sufficient water permeability even if the kind and amount of the binder are selected. If the particle size is too large, it is difficult to obtain a desired bending strength even if the type and amount of the binder are adjusted.

  Moreover, in this invention, it is preferable that the aggregate with a small particle diameter is not substantially mixed with these aggregates. In the present invention, the aggregate preferably has a particle diameter in the range of 1 mm to 10 mm, and the content of the aggregate having a small particle diameter passing through the sieve size of 1.2 mm is less than 5% by mass, preferably 3% by mass. Is less than.

  In the present invention, preferred aggregate has a particle size distribution evaluated by the value of the uniformity coefficient Uc (= U60 / U10) of less than 4, preferably in the range of 1 to 3. The larger the value of the uniformity coefficient is, the larger and smaller aggregates are mixed, and the filler is compacted and well-tightened when filling the mold, making it difficult to increase water permeability. Here, U60 is the particle size when the passing rate of the sieve is 60%, and U10 is the particle size when the passing rate of the sieve is 10%, and is calculated from the screening data.

  An example of aggregate screening data preferably used in the present invention is shown in Table 1 and FIG. As shown in Table 1 and FIG. 6, the Yamato cherry tree indicated by reference numeral 1, earthenware gravel indicated by reference numeral 2, blue gravel indicated by reference numeral 3 and Tawa gravel No. 7 indicated by reference numeral 4 Aggregate screened to meet the conditions is selected as the preferred aggregate.

以上の条件を満たすことにより、本発明においては、粒子径が比較的大きな骨材を用いても、比較的大きな曲げ強度を得ることができるという特徴を備えている。例えば、２ｍｍを越える粒子径の骨材を主体としても、４ＭＰａ程度の曲げ強度を容易に得ることができる。透水性能は、長期間の使用に対して、詰まりなどを引き起こしやすいので、性能的に十分に余裕を有して設計することが好ましい。それ故、透水平板としては、所望の曲げ強度が得られれば、透水性能が大きい方が望ましい。そこで、この発明では、４ＭＰａ程度の曲げ強度を得るために、例えば、平均粒子径が５ｍｍ程度以上の骨材を用いることができる。
［製造方法の説明］
つぎにこのような材料を用いた透水平板の製造方法の一例について説明する。

By satisfying the above conditions, the present invention has a feature that a relatively large bending strength can be obtained even when an aggregate having a relatively large particle diameter is used. For example, a bending strength of about 4 MPa can be easily obtained even with an aggregate having a particle diameter exceeding 2 mm as a main component. The water permeation performance is liable to cause clogging and the like for long-term use, and therefore it is preferable to design with a sufficient margin in terms of performance. Therefore, as the permeable horizontal plate, it is desirable that the water permeable performance is larger as long as a desired bending strength is obtained. Therefore, in the present invention, in order to obtain a bending strength of about 4 MPa, for example, an aggregate having an average particle diameter of about 5 mm or more can be used.
[Description of manufacturing method]
Next, an example of a method for producing a transparent horizontal plate using such a material will be described.

  First, in the method for producing a transparent horizontal plate of the present invention, a surface layer block material and a base layer block material are prepared by blending appropriate amounts of the above-mentioned thickener, cement, and aggregate.

  The surface layer block material and the base layer block material include cement C mixed with a polymer thickener, water (W), and an aggregate having a particle size within a range of 1 mm to 10 mm and an equality coefficient of less than 4. The mass ratio (W / C) of water (W) to the total mass of the cement C is in the range of 0.20 to 0.35.

  If the ratio of water used is within this range, the surface layer block material and the base layer block material may all have the same composition or may be different. For example, as the surface layer block material exposed as an outer surface, an aggregate having excellent decorativeness may be used.

  In the present invention, as shown in FIG. 1, the base layer block material filling step (10) is performed in which the base layer block material is filled into the mold while giving vibration, and the filling is compressed while giving vibration immediately after filling. A mold clamping step (20) for compaction by applying force, a surface block material filling step (30) for sequentially filling the surface form block material into the mold while applying vibration, and a filling material while applying vibration immediately after filling A molding step (40) is essentially necessary for molding by applying a compression force to the.

  In the filling step (10, 30), at least two filling steps including the base layer block material and the surface layer block material are sequentially performed, and each filling step (10, 30) is filled while applying vibration. It is necessary to perform the clamping step (20) and the molding step (40) immediately after each filling step (10, 30).

  As in the prior art, if the surface layer block material and the base layer block material are filled in this order, it will be difficult to efficiently apply the catalyst layer, as will be described later.

  In addition, each filling step (10, 30) is performed while applying vibration, and quick clamping is performed during each filling step (10, 30), thereby producing a transparent horizontal plate having excellent bending strength and water permeability. It becomes possible to do. In the case of manufacturing by a single filling process, even if the kind and amount of the binder are limited, either the bending strength is insufficient or the water permeability is sacrificed.

  Here, the block material filling step (10) for the base layer is performed under the condition of the motor frequency within the range of 3000 to 4000 revolutions / minute and with the material supply time within the range of 1 second to 3 seconds.

Next, the mold clamping step (20) is performed at a mold clamping pressure within a range of 15 kg / cm ^{2 to} 50 kg / cm ² for 0.1 seconds under conditions of a motor frequency within a range of 1500 rotations / minute to 2000 rotations / minute. Time clamping within a range of ~ 1 second.

  Moreover, the block material filling step (30) for the surface layer is performed with the material supply time within the range of 1 second to 3 seconds under the condition of the motor frequency within the range of 3000 rotations / minute to 4000 rotations / minute.

Further, the molding step (40) is performed at a clamping frequency within a range of 15 kg / cm ^{2 to} 50 kg / cm ² at a motor frequency within a range of 1500 revolutions / minute to 2000 revolutions / minute for 2 seconds to 5 seconds. Time clamped within the range of

  By adopting such conditions, it is possible to manufacture a transparent horizontal plate with excellent bending strength and water permeability by filling and clamping in an extremely short time.

  After the forming step (40), a transparent horizontal plate can be obtained by appropriately combining a demolding step, a curing step and, if necessary, a surface treatment step according to a conventional method.

  Here, in FIG. 2, after the molding step (40), a demolding step (50), a curing step (60), and a surface treatment step (70) are sequentially performed. An example of this surface treatment step is to process the surface of the surface layer part of the molded product that has been demolded using a wet polishing machine and an ultra-high pressure processing machine, or to appropriately decorate the surface of the molded product, And / or a process of enhancing the function of the transparent horizontal plate by applying a photocatalyst or the like.

  Moreover, in FIG. 3, the catalyst provision process (71) as a surface treatment process (70) is performed between a shaping | molding process (40) and a demolding process (50), and then a demolding process (50) and a curing process are performed. After (60), a surface processing step (72) is performed as a surface treatment step (70) for processing using a wet polishing machine and an ultrahigh pressure processing machine.

  In FIG. 4, the curing process is performed before and after the demolding process (50), and the pre-curing process (61) and the demolding process (50) and the post-curing process (62) are performed sequentially after the molding process (40). ing. Moreover, in FIG. 5, the catalyst provision process (71) is performed after the surface processing process (72).

  Here, according to the method for producing a transparent horizontal plate of the present invention, since the base layer block material is filled in the mold and then the surface layer block material is filled, the mold is immediately after the molding step (40). The surface layer portion is disposed on the upper side of the block material existing inside. Thereby, since the surface of a surface layer part can be exposed even in the state before a demolding process (50), catalysts, such as a photocatalyst, can be provided to this surface.

  Here, the application method for applying the photocatalyst is not particularly limited. For example, a method using a general slurry can be adopted, but a titanium oxide derived from a reaction product of a peroxotitanate ion aqueous solution or a titanium salt aqueous solution and hydrogen peroxide proposed by the present inventors is directly formed into a film. Also good.

  That is, a slurry containing titanium oxide as a NOx removal catalyst that functions as a photocatalyst is sprayed at an appropriate stage after the forming step (40) and before the curing step (60), so that the titanium oxide is formed from the surface side. The slurry can be applied. In addition, by providing the titanium oxide slurry in the pre-curing step in this way, the slurry drying and the cement curing are performed simultaneously in the curing process while sufficiently reacting the titanium oxide and the cement. This allows the titanium oxide to stick to the cement.

  Similarly, for example, after forming the titanium oxide film as a NOx removing catalyst that functions as a photocatalyst by acting a peroxotitanate ion aqueous solution from the surface side after the molding process and before the curing process. Can also be cured. Similarly, after the molding step and before the curing step, after the titanium salt aqueous solution is acted from the surface side, the hydrogen peroxide solution is acted on, so that the oxidation as a NOx removal catalyst that functions as a photocatalyst is performed. A titanium film can also be formed. Before the curing process, there is sufficient alkali derived from cement, so that the titanium oxide film can be formed smoothly.

  And according to such a manufacturing method, a catalyst coating step (71) for applying a catalyst is only added, and a titanium oxide film is formed on the surface layer portion without passing through a special drying step. It is possible to obtain a function and effect unique to the present invention. In any case, the titanium oxide film can be fixed to the surface layer portion by performing curing thereafter.

Here, the peroxotitanate aqueous solution used in the present invention may be an aqueous solution containing peroxotitanate ions (chemical formula) derived from peroxotitanate (titanium peroxide: TiO ₃ · nH ₂ O). The manufacturing method is not particularly limited. For example, a peroxotitanate ion aqueous solution can be easily obtained by mixing a titanium salt aqueous solution such as a titanium sulfate (Ti (SO ₄ ) ₂ ) aqueous solution or a titanium chloride (TiCl ₄ ) aqueous solution with a hydrogen peroxide solution. .

In addition to titanium sulfate and titanium chloride, titanium salts used in such an aqueous solution of titanium salt include potassium peroxotitanate (K ₄ TiO ₈ · 6H ₂ O), sodium peroxotitanate (Na ₄ TiO ₈ · 2H ₂ O or Na ₂ O ₂ · TiO ₃ · 3H ₂ O) or the like can be used, but is not particularly limited as long as it is a water-soluble titanium salt that dissolves in water and generates peroxotitanate ions.

  When titanium oxide is selected as the catalyst, even if high temperature curing using steam or the like is performed in the curing step (60), the catalytic performance of titanium oxide is stable at a temperature of about steam, so that the catalytic performance is high. Is not reduced. In the case of steam curing, titanium oxide can be made into a photocatalyst coating layer firmly adhered to the cement component adhering to the aggregate surface without reducing the catalytic ability.

  In addition, the catalyst for removing NOx can be applied by spraying or dipping after the surface processing step (72) as shown in FIG.

  As such titanium oxide, for example, a commercially available product in the form of an aqueous dispersion such as a slurry can be used as it is. In general, when the average particle diameter of titanium oxide exceeds 40 nm, it is said that the activity as a photocatalyst is reduced and the NOx reduction effect is reduced. Therefore, also in the present invention, the average particle diameter is desirably 40 nm or less.

  The titanium oxide may be a rutile type, but an anatase type titanium oxide having better activity is desirable.

  In addition, as described above, in the stage after this curing process, the method using the above-described general slurry can be adopted, but the present inventors have proposed a peroxotitanate ion aqueous solution or a titanium salt aqueous solution and peroxidation. Titanium oxide derived from a reaction product with hydrogen may be directly formed. In this case, the reaction product of the aqueous solution of peroxotitanate ion or titanium salt and hydrogen peroxide can be the same as that described above. In the post-curing stage, the base material may not have sufficient alkalinity. In this case, after holding an appropriate alkali-containing material, a peroxotitanate ion aqueous solution is allowed to act, or a titanium salt. After the action of the aqueous solution, hydrogen peroxide is allowed to act.

  In the present invention, a titanium oxide film is formed by reacting an alkali and peroxotitanate ions. Thereby, titanium oxide is not generated in the deep layer portion of the transparent horizontal plate, but only on the surface (or on the surface layer). Titanium oxide film can be efficiently formed only on the part). That is, since titanium oxide exhibits a photocatalytic function when irradiated with ultraviolet rays, if a titanium oxide film is formed on the surface of the transparent horizontal plate, a larger effect can be obtained with a small amount of titanium.

  Here, this alkali may be held on the surface of the transparent horizontal plate in any manner. For example, the transparent horizontal plate itself may be formed from an alkali-containing material, and the surface thereof may be configured to have alkali. Alternatively, the transparent horizontal plate may be provided with a separate alkali-containing material so that the surface is You may comprise so that it may have an alkali.

  Furthermore, you may make an alkali adhere to the surface by apply | coating, spraying, immersing, etc. an alkali containing liquid to a transparent horizontal board. In this case, since the water permeable plate used in the present invention has a water permeability of 0.1 cm / second or more, it is suitable for holding the alkali more uniformly on the surface. This is because if alkali-containing liquid is sprayed on the transparent horizontal plate, the alkali is supported in the communication holes near the surface layer of the transparent horizontal plate.

Alkali metal hydroxides, alkaline earth metal hydroxides, and the like can be used as the alkali imparted to the surface. For example, sodium hydroxide (NaOH), calcium hydroxide (Ca (OH) ₂ ), hydroxide Strontium (Sr (OH) ₂ ), barium hydroxide (Ba (OH) ₂ ), or the like can be used. Furthermore, ammonia (NH ₃ ) or the like can also be used as the alkali.

The deposition amount of such titanium oxide is preferably in the range of 5g / m ² ~100g / m ² at a solid concentration of titanium oxide. When the amount of film formation is small, the catalytic ability is not sufficiently exhibited. Moreover, when the film-forming amount is applied more than necessary, the thickness of the obtained coating film increases, so that the adhesiveness to the cement component is lowered and the catalyst may fall off.

  Next, as a method of forming a film mainly composed of titanium oxide, after applying the titanium oxide slurry as described above, it is dried at room temperature or heat-treated at a temperature of 850 ° C. or less. If it is higher than 850 ° C., the crystal structure of titanium oxide is changed and the photocatalytic activity is lowered.

Hereinafter, the effects of the present invention will be described with reference to examples, but the present invention is not limited to the following examples. The materials and equipment used in the examples are as follows.
[Surface aggregate]: Beautifully colored crushed stone. The particle size range was selected from 10 mm to 1.2 mm with a sieve and used.
[Lower layer aggregate]: No. 7 crushed stone (mainly having a particle size of 5 mm to 2.5 mm, with a uniformity coefficient of 2 or less).
[Cement]: White Portland cement [Thickener]: Acrylic (trade name Polytron A1500 manufactured by Asahi Kasei)
[White flower inhibitor]: Fatty acid anionic surfactant (Eflorescence inhibitor manufactured by NM Co., Ltd .: Trade name Lubrilith 640)
Molding device with vibration generator:
Permeability coefficient: Measured according to the on-site permeability test method (draft) of the permeable pavement shown by the Japan Road Construction Industry boundary in the permeable pavement handbook.
Bending strength load: Measured according to JIS A 5371: 2004 (Appendix 2).
<Example 1>
After kneading 80 parts by mass of aggregate and 20 parts by mass of cement, 25 parts by mass of 30 parts by mass of water, 0.01 to 3 parts by mass of thickener and 0.5 to 3 parts by mass with respect to 100 parts by mass of cement. A white block inhibitor was added and mixed and stirred with a mixer to prepare a surface layer block material and a lower layer block material.

A mold frame of 30 cm in length and width and 6 cm in depth is set in a molding apparatus, and the motor frequency is within a range of 3000 rpm / min to 4000 rpm / minute (for example, 3780 rpm), 1 second to 3 seconds After the lower layer block material was supplied for a material supply time within a range of seconds (for example, about 2.3 seconds), the mold was immediately clamped. This clamping is within the range of 0.1 second to 1 second under the condition of the motor frequency within the range of 1500 rpm to 2000 rpm with the clamping pressure within the range of 15 kg / cm ^{2 to} 50 kg / cm ² . (For example, 0.3 seconds).

Then, the mold is opened and the surface block material is supplied immediately. The surface layer block material filling step is performed at a material frequency within a range of 1 second to 3 seconds (for example, 3780 rotations / minute) under conditions of a motor frequency within a range of 3000 rotations / minute to 4000 rotations / minute ( For example, the molding process is performed under the condition of motor frequency within the range of 1500 rpm to 2000 rpm with the clamping pressure within the range of 15 kg / cm ^{2 to} 50 kg / cm ^2. The time clamping in the range of 2 to 5 seconds (for example, 3 to 4 seconds) is performed.

  After molding, each mold was removed from the molding apparatus and cured in a curing chamber maintained at 40 ° to 60 ° for 6 to 12 hours.

  The obtained product processed the surface of the surface layer part using wet polishing and an ultra-high pressure processing machine after curing to obtain a transparent horizontal plate.

  The obtained permeable horizontal plate is a water permeable block in which cement is used as a main binder to form a gap between aggregates to maintain water permeability, and a surface layer portion having an average thickness of about 8 mm and a base portion having an average thickness of about 52 mm; Was a rectangular flat plate having a total thickness of about 60 mm.

The permeability coefficient of this permeable horizontal plate was about 0.27 cm / s to 0.35 cm / s, the bending strength load was about 14 kN to 15 kN, and the water permeability coefficient as a reference value was 0.01 cm / second. .
<Example 2>
In Example 1, before entering the curing room, a slurry containing NOx removal catalyst functioning as a photocatalyst was sprayed on the surface layer of the mold together with the mold, followed by curing.

  In the same manner, a transparent horizontal plate having the same dimensions and the same performance as in Example 1 was obtained.

  When the surface of the obtained transparent horizontal plate was observed with an electron microscope, it was confirmed that a thin film of titanium oxide was formed on the surface aggregate surface.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the present invention can be changed even if there is a design change or the like without departing from the gist of the present invention. included.

  For example, the above embodiment relates to a permeable concrete block (transparent horizontal plate) having a two-layer structure of a surface layer material portion and a lower layer material portion. However, the present invention is not limited to this, and the present invention is not limited to this. Even the above multilayer structure can be implemented.

  Further, when the mold is clamped, if the mold frame or the pressing lid is provided with irregularities, a transparent horizontal plate having a shape substantially conforming to the irregularities can be obtained. Thereby, it can also be set as the translucent horizontal board provided with designability and functionality.

In addition, although the transparent horizontal plate in the above embodiment is a square, it may be a polygon in the plan view, other polygons such as a triangle, a circle, an ellipse, or any other shape.
<Example 3>
Samples 1 to 15 were manufactured by the following steps.
(1) Step of holding alkali-containing material on transparent horizontal plate A paste-like alkali-containing material was applied to the surface of a transparent horizontal plate (width 10 cm × length 20 cm × thickness 6 cm) as a base material. As shown in Table 2, as the alkali-containing material, cement was used for Sample 1 to Sample 11, calcium hydroxide was used for Sample 12 and Sample 13, and strontium hydroxide was used for Sample 14 and Sample 15, respectively. .
(2) Step of attaching peroxotitanate aqueous solution to transparent horizontal plate Samples 1 to 9 and Samples 12 to 15 had a cement dried and solidified, and Samples 10 and 11 had a per Oxitanate ion aqueous solution was sprayed. As shown in Table 2, as peroxotitanate ion aqueous solutions, Sample 1 to Sample 4 were mixed with a titanium chloride aqueous solution and a hydrogen peroxide solution, and Samples 5 to 15 were a titanium sulfate aqueous solution and a peroxide. Each mixed solution with hydrogen water was used.
(3) Immersion in deionized water and drying step Samples 3, 11, 13, and 15 were immersed in deionized water. In this step, the target sample was immersed in 1.4 l of deionized water for 1 day and then dried. For sample 4, this dipping / drying process was repeated twice.
<Example 4>
Sample 16 and Sample 17 were manufactured by the following steps.
(1) Step of holding alkali-containing material on transparent horizontal plate A paste-like alkali-containing material was applied to the surface of the same transparent horizontal plate as in Example 3. As shown in Table 2, cement was used as the alkali-containing material.
(2) A process of attaching a soluble titanium salt aqueous solution to the surface of a permeable horizontal plate It was made to adhere by spraying the soluble titanium salt aqueous solution on the surface of the cement held by the permeable horizontal plate. Here, a titanium sulfate aqueous solution was used as the soluble titanium salt aqueous solution.
(3) Step of attaching hydrogen peroxide solution to transparent horizontal plate It was made to adhere by spraying hydrogen peroxide solution on the surface of cement to which the titanium sulfate aqueous solution was attached.
(4) Immersion in deionized water and drying step Sample 17 was immersed in deionized water. In this step, the target sample was immersed in 1.4 l of deionized water for 1 day and then dried.
<Example 5>
Sample 18 was manufactured by the following process.
(1) Step of attaching peroxotitanate ion aqueous solution to transparent horizontal plate It was made to adhere by spraying 10 g of peroxotitanate ion aqueous solution to the alkali-containing material. Here, 25 g of fly ash was used as the alkali-containing material. This fly ash is an alkaline powder and has alkali on its surface. Further, as shown in Table 2, a mixed solution of a titanium sulfate aqueous solution and a hydrogen peroxide solution was used as the peroxotitanate ion aqueous solution.

Moreover, it was made to dry after spraying peroxotitanate ion aqueous solution.
(2) Step of depositing fly ash on a transparent horizontal plate Fly ash to which a peroxotitanate ion aqueous solution was adhered was deposited on a transparent horizontal plate (similar to Example 3).
<Example 6>
Samples 19 to 29 were manufactured by the following steps.
(1) Step of adhering alkali to a permeable horizontal plate The surface of a permeable horizontal plate (similar to Example 3) was impregnated on the surface by spraying an aqueous alkali solution, thereby causing alkali to adhere. As shown in Table 3, a sodium hydroxide aqueous solution was used for samples 19 to 21 and a barium hydroxide aqueous solution was used for samples 22 to 29 as alkaline aqueous solutions.
(2) Step of attaching hydrogen peroxide solution to the transparent horizontal plate It was attached by spraying hydrogen peroxide solution on the surface of the transparent horizontal plate to which the alkaline aqueous solution was attached.
(3) Immersion in deionized water and drying step Samples 20, 23, 26, and 29 were immersed in deionized water. In this step, the target sample was immersed in 1.4 l of deionized water for 1 day and then dried. For samples 21, 24, and 27, this dipping / drying process was repeated twice.
<Example 7>
Samples 32 to 36 were manufactured by the following steps.
(1) Step of mixing titanium-containing hydrogen peroxide solution and aqueous alkali solution As shown in Table 4, an aqueous solution in which hydrogen peroxide solution is added to a titanium sulfate aqueous solution or a titanium chloride aqueous solution (Ti-H ₂ O ₂ aqueous solution) Sodium hydroxide, barium hydroxide octahydrate, or strontium hydroxide octahydrate was added to form a pale yellow or white precipitate.
(2) Step of removing water-soluble component from precipitate The aqueous solution obtained by mixing as described above was allowed to stand, the supernatant was removed, and 100 ml of water was mixed. Furthermore, this aqueous solution was allowed to stand, the supernatant was removed, and the operation of mixing water was repeated several times. And the water-soluble component was removed by filtering a deposit.
(3) Step of drying precipitate After the obtained precipitate was dried in a desiccator containing silica gel, it was dried in an electric dryer maintained at about 107 ° C. to obtain Samples 32 to 36.
<Reference Example 1>
As Reference Example 1, Sample 30 and Sample 31 were manufactured by a conventional film forming method using a titanium oxide-containing gel.
(1) Adjustment process of titanium oxide-containing gel Aqueous ammonia (NH ₄ OH) is added to a mixed aqueous solution of a titanium sulfate aqueous solution and a hydrogen peroxide solution to adjust the pH to 7, whereby a suspension containing a yellow gel substance A liquid was obtained.
(2) Step of attaching the suspension to the permeable horizontal plate The suspension was attached to the permeable horizontal plate (similar to Example 3).
(3) Soaking in deionized water and drying step Sample 31 was immersed in deionized water. In this step, the target sample was immersed in 1.4 l of deionized water for 1 day and then dried.
<Reference Example 2>
As Reference Example 2, a paste-like cement was applied to a transparent horizontal plate (similar to Example 3), and a sample 32 without a titanium oxide film was manufactured.
(B) Measurement experiment and result of photocatalytic ability and composition of each sample The following experiment was conducted about the samples 1-36 obtained in Examples 3 to 7 and Reference Examples 1 and 2.
(B-1) Nitric Oxide Adsorption Rate Measurement (B-1-1) Experimental Method (1) Measurement container (length 10 cm × width 20 cm × thickness 8 cm) in which sample 1 is formed of quartz glass on the upper surface Set. At this time, the sample 1 was disposed so that the surface (the surface on which the titanium oxide film was formed) faced upward.
(2) A gas containing nitrogen monoxide (NO-containing gas) was supplied at 0.5 l / min from one end in the longitudinal direction of the measurement container and discharged from the other end. As the NO-containing gas, a gas having a volume ratio of NO: 4.7 ppm, O ₂ : 10.5 vol%, N ₂ : 89.5 vol% (hereinafter referred to as “first NO-containing gas”), NO: A gas having a volume ratio of 4.7 ppm, N ₂ : 100.0 vol% (hereinafter referred to as “second NO-containing gas”), and a gas having a higher NO concentration than 4.7 ppm were used.
(3) The NO concentration of the gas (exhaust gas) discharged from the other end was measured using a chemiluminescence NO concentration measuring device (TN-7: Yanagimoto Seisakusho). Furthermore, the nitrogen dioxide concentration of the exhaust gas was measured by the detector tube method.
(4) The above (1) to (3) were performed for each of the samples 2 to 32.
(B-1-2) Experimental results (1) During the passage of the first NO gas, the NO concentration of the exhaust gas from the measurement container was the first of the samples 1 to 31 that were supplied to the measurement container. It decreased from the NO concentration (4.7 ppm) of one NO gas.

Further, nitrogen dioxide was not detected from the exhaust gas (below the lower limit of detection). Then, even if the second NO-containing gas does not contain oxygen is vented, reduction in NO concentration comparable to the first NO-containing gas is confirmed, and, O ₂ concentration did not decrease.

  Furthermore, in the case of ventilating a gas having a higher NO concentration than 4.7 ppm, the rate of decrease in the NO concentration increased.

On the other hand, in the sample 32, the NO concentration hardly decreased.
(2) The NO adsorption rate was obtained from the following formula from the decrease rate of the NO concentration. This NO adsorption rate corresponds to the NO decrease rate when each sample is not irradiated with ultraviolet rays.

NO adsorption rate (μmol / h) = aeration gas flow rate (l · N / h) × (air supply gas NO concentration−exhaust gas NO concentration) (ppm) /22.4 (l · N / mol)
The results obtained are shown in Tables 2 and 3.
(3) Further, from the experimental results of Samples 1 to 3 and Samples 5 to 9, the relationship between H ₂ O ₂ / Ti (molar ratio, the same applies hereinafter) of the sprayed peroxotitanate ion aqueous solution and the NO adsorption rate is illustrated. 7 shows.
(4) From the experimental results of Samples 6, 12, 14, 19, and 22, NO adsorption rates compared by alkali type are shown in FIG.
(5) Based on the experimental results of samples 22, 23, 25, 26, 28, and 29, Ba (OH) ₂ / Ti (molar ratio, the same applies hereinafter) and NO adsorption in sprayed barium hydroxide and peroxotitanate aqueous solutions The relationship with speed is shown in FIG.
(B-2) Nitric Oxide Photooxidation Rate Measurement (B-2-1) Experimental Method (1) Sample 1 was measured using a measuring vessel having an upper surface made of quartz glass (length 10 cm × width 20 cm × thickness 8 cm). ). At this time, the sample 1 was disposed so that the surface (the surface on which the titanium oxide film was formed) faced upward.
(2) The first NO-containing gas was supplied at 0.5 l / min from one end in the longitudinal direction of the measurement container and discharged from the other end. Furthermore, ultraviolet rays were irradiated at 0.6 W / cm ² from the upper surface made of quartz glass while venting the first NO-containing gas in this way.
(3) The NO concentration of exhaust gas was measured using a chemiluminescence NO concentration measuring device (TN-7: Yanagimoto Seisakusho). Furthermore, the nitrogen dioxide concentration of the exhaust gas was measured by the detector tube method.
(4) The above (1) to (3) were performed for each of the samples 2 to 31.
(B-2-2) Experimental results (1) When the irradiation with ultraviolet rays was started, the NO concentration began to decrease, and after a certain period of time, the NO concentration in the exhaust gas became constant. The NO photooxidation rate was determined by the following equation using the NO reduction rate when the steady state was obtained as described above, and the results are shown in Tables 2 and 3.

NO photooxidation rate (μmol / h) = aeration gas flow rate (l · N / h) × (air supply gas NO concentration−exhaust gas NO concentration) (ppm) /22.4 (l · N / mol)
(2) From the experimental results of Samples 1 to 3 and Samples 5 to 9, the relationship between the H ₂ O ₂ / Ti of the sprayed peroxotitanate ion aqueous solution and the NO light adsorption rate is shown in FIG.
(3) Furthermore, from the experimental results of Samples 6, 12, 14, 19, and 22, the NO photooxidation rate depending on the type of alkali is shown in FIG.
(4) From the experimental results of samples 22, 23, 25, 26, 28, and 29, the relationship between Ba (OH) ₂ / Ti and NO photooxidation rate in sprayed barium hydroxide and aqueous peroxotitanate ions is shown. This is shown in FIG.
(B-3) Identification of photocatalytic active component (B-3-1) Experimental method (1) X-ray diffraction measurement was performed for each of samples 32-36.
(2) About each of samples 32-36, the composition analysis was performed by X-ray photoelectron spectroscopy (X-ray photoelectron spectrometer 5000 type | mold by ULVAC-PHI Co., Ltd.).
(B-3-2) Experimental results (1) X-ray diffraction patterns of Samples 32-36 are shown in 137.
(2) Table 5 shows the measurement results of X-ray photoelectron spectroscopy.

（Ｃ）考察
（Ｃ−１）酸化チタン膜のＮＯ吸着性及びＮＯ光酸化速度
試料１〜試料３１の総てについて、測定用容器からの排出ガスのＮＯ濃度は測定用容器に送気したガスのＮＯ濃度（４．７ｐｐｍ）より低下した。

(C) Consideration (C-1) NO adsorption property and NO photo-oxidation rate of titanium oxide film For all of Samples 1 to 31, the NO concentration of the exhaust gas from the measurement vessel is the gas sent to the measurement vessel NO concentration (4.7 ppm).

It was confirmed that nitrogen dioxide was not detected from the exhaust gas, and that the NO concentration decreased as much as the first NO-containing gas even when the second NO-containing gas not containing oxygen was vented. In addition, since the O ₂ concentration did not decrease, it was confirmed that the decrease in the NO concentration was not based on the conversion from NO to NO ₂ .

  In addition, when the gas having a higher NO concentration than 4.7 ppm was vented, the rate of decrease in the NO concentration increased. Thereby, it is thought that the decrease in the NO concentration is due to adsorption of NO by the transparent horizontal plates (sample 1 to sample 31) having the titanium oxide film. Furthermore, in the sample 32 which was only coated with cement and not provided with a titanium oxide film, the NO concentration was hardly lowered. Therefore, NO adsorption is considered to be related to the titanium oxide film.

Moreover, although the NO adsorption performance and the NO photo-oxidation performance were confirmed also in the sample 30 and the sample 31, the values thereof are lower than those of the samples 5, 16, 17, 20, 21, 25, 29, and the like. ing. From this, it was found that the titanium oxide film formed based on the titanate ion aqueous solution can disperse titanium oxide more highly than the titanium oxide attached as a gel. This is because, according to such a method for forming a titanium oxide film, an aqueous solution in which ionic titanium (peroxotitanate ion) is dissolved is used, so that a film containing solid titanium oxide is attached. It is considered that titanium oxide can be highly dispersed.
(C-2) Dependence of NO adsorption rate on H ₂ O ₂ / Ti As shown in FIG. 7, when titanium sulfate is used as the titanium salt, H ₂ O ₂ / Ti is about 0.1 to 1. The NO adsorption rate greatly increased when H ₂ O ₂ / Ti was greater than 1. On the other hand, when titanium chloride was used as the titanium salt, the NO adsorption rate was substantially constant when H ₂ O ₂ / Ti was in the range of 0.1 to ₂ . Samples 3 and 7 immersed in deionized water for one day and dried were samples 1 and 6 having the same H ₂ O ₂ / Ti (H ₂ O ₂ / Ti = 1) and not immersed in deionized water. Higher adsorption rate.
(C-3) NO adsorption rate based on alkali difference As shown in FIG. 9, the sample 12 using calcium hydroxide as the alkali and the sample 14 using strontium hydroxide showed a high NO adsorption rate. In the samples 13 and 15 in which these are immersed in water, the NO adsorption rate is greatly reduced.

According to the results of Samples 19 and 22 using barium hydroxide or sodium hydroxide as the alkali, it was not possible to confirm a great difference from the NO adsorption rate of Samples 20 and 23 in which these were immersed in water.
(C-4) NO photooxidation rate based on alkali difference As shown in FIG. 10, the NO photooxidation rate is the same as the sample 12 not immersed in water, except for the samples 6 and 7 using cement as an alkali. Compared with 14, 19, and 22, Samples 13, 15, 20, and 23 immersed in water showed the same or higher values. From this, it is considered that when an alkali other than cement is used, there is no change in the characteristics that the NO photooxidation rate is remarkably reduced at least by being immersed in water.
(C-5) Dependence of NO photooxidation rate on H ₂ O ₂ / Ti As shown in FIG. 8, when titanium chloride is used as the soluble titanium salt, regardless of the value of H ₂ O ₂ / Ti. The NO photooxidation rate became substantially constant. On the other hand, in the case of using titanium sulfate as a soluble titanium salt, the increase in H ₂ O ₂ ratio (i.e., H ₂ O ₂ / increase of Ti) NO photooxidation rate due to increases, H ₂ O ₂ / Ti When the value was about 2, the change was minute and the NO photooxidation rate was substantially constant. Samples 3 and 7, which were dipped in deionized water for one day and dried, had the same H ₂ O ₂ / Ti value (H ₂ O ₂ / Ti = 1) and were not immersed in deionized water. 6, the NO adsorption rate was lower, but the NO resolution remained.

The results of such FIG. 8, H ₂ O ₂ / Ti during the formation of the titanium oxide film is preferably used to be _{0.1 ≦ H 2 O 2 / Ti} , a smaller amount of titanium efficiency In order to adsorb NO specifically, it is considered that 1.0 ≦ H ₂ O ₂ /Ti≦2.0 is preferable.

Further, as shown in Table 2, it was found that Samples 16 and 17 also showed a high NO photooxidation rate (4.02 μmol / h). That is, it is understood that a titanium oxide film showing a high NO photooxidation rate can be formed by a film forming method in which a titanium sulfate aqueous solution is sprayed on a transparent horizontal plate holding cement as an alkali-containing material and then hydrogen peroxide water is sprayed. It was. Moreover, Sample 17 that had been dipped in 1.4 l of deionized water for 1 day and dried also showed the same high NO photooxidation rate (4.02 μmol / h). It is considered that a titanium oxide film that is difficult to be detached, that is, fixed, can be formed.
(C-6) Relationship between NO adsorption rate and NO photo-oxidation rate and alkali / Ti (molar ratio, the same shall apply hereinafter) As shown in FIG. 11, the NO adsorption rate depends on the value of Ba (OH) ₂ / Ti. The value was almost constant without much dependence.

Further, the NO photooxidation rate tends to increase as Ba (OH) ₂ / Ti increases in the range of 0.25 ≦ Ba (OH) ₂ / Ti <1, and Ba (OH) Near ₂ / Ti = 1, it was substantially constant.

From these results, when Ba (OH) ₂ is used as at least an alkali, the molar ratio is 0.25 ≦ Ba (OH) ₂ / Ti ≦ 1, preferably Ba (OH) ₂ / Ti≈1. Thus, it is considered good to determine the value of Ba (OH) ₂ / Ti.
(C-7) Crystal Structure of Photocatalytically Active Component Referring to FIG. 13, in the Ti (SO ₄ ) ₂ —H ₂ O ₂ —NaOH system, only a wide peak (broad peak) appears, so that it is amorphous. It is thought that the quality component was generated.

In the TiCl ₄ —H ₂ O ₂ —Ca (OH) ₂ system, TiCl ₄ —H ₂ O ₂ —Sr (OH) ₂ system, and TiCl ₄ —H ₂ O ₂ —Ba (OH) ₂ system, A diffraction peak derived from the salt (CaCO ₃ , SrCO ₃ , BaCO ₃ ) was detected. Furthermore, a broad peak derived from an amorphous substance was also detected. These detected carbonates are presumed to have been produced by the absorption of CO ₂ present in the air by the alkaline aqueous solution during the sample production process. These carbonates are considered to remain in the precipitate because of their poor water solubility. Since this carbonate is sparingly water-soluble, it does not easily elute even when it comes into contact with water, and it can be considered that it can function as a binder that retains amorphous titanium dioxide and prevents elution. Therefore, when forming a titanium oxide film, Ca (OH) ₂ , Sr (OH) ₂ , or Ba (OH) is used as an alkali, and a peroxotitanate ion aqueous solution to the extent that this alkali remains is adhered. Then, it is considered that carbonate is generated with time by contact with air, elution of amorphous titanium dioxide is prevented, and durability of the titanium oxide film can be improved.

Further, TiCl ₄ —H ₂ O ₂ —Ca (OH) ₂ system, TiCl ₄ —H ₂ O ₂ —Sr (OH) ₂ system, and TiCl ₄ —H ₂ O ₂ —Ba using titanium chloride as a titanium salt. In the (OH) ₂ system, it is considered that sodium chloride, calcium chloride or barium chloride is produced, but these are not detected from the precipitate. This is because sodium chloride, calcium chloride or barium chloride is water-soluble. Therefore, if titanium chloride is used as the titanium salt and any one of calcium hydroxide, strontium hydroxide and barium hydroxide is used as the alkaline earth metal hydroxide, chlorine (chlorine compound) can be easily washed. Can be removed.

  On the other hand, according to the method for forming a titanium oxide film of the present invention in which the titanium salt is titanium sulfate and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide, When producing titanium oxide, calcium sulfate, strontium sulfate, or barium sulfate is produced. And since this calcium sulfate, strontium sulfate, or barium sulfate functions as a binder of titanium oxide (titanium dioxide) without substantially reducing the photocatalytic ability of the titanium oxide film, it is difficult for titanium oxide to elute due to rain, etc. A highly durable titanium oxide film can be formed.

In addition, in the Ti (SO ₄ ) ₂ —H ₂ O ₂ —Ba (OH) ₂ system, a broad diffraction peak is detected in addition to a clear diffraction peak derived from poorly water-soluble barium sulfate (Ba (SO ₄ ) ₂ ). It was done. A broad peak appears in common in the X-ray diffraction patterns of these precipitates. From this, it is presumed that the titanium oxide film formed according to the present invention is a photocatalytic component in which the amorphous component shows activity in NO photooxidation.
When (C-8) Referring to identify table 5 of the photocatalytic active _{component, Ti (SO 4) 2 -H} 2 O 2 -NaOH _{system, TiCl 4 -H 2 O 2 -Ca} (OH) 2 system, TiCl ₄ -H _{In the 2} O ₂ —Sr (OH) ₂ system and the TiCl ₄ —H ₂ O ₂ —Ba (OH) ₂ system, each precipitate contains titanium, oxygen, alkali or alkaline earth metal, , Found to contain carbon. Here, assuming that the alkali of each of these precipitates is all present as carbonate (MCO ₃ ), the atomic ratio between the remaining oxygen and titanium was found to be almost 2 (Ti: O≈ 1: 2). From this, it is estimated that titanium exists as titanium dioxide (TiO ₂ ).

On the other hand, in the Ti (SO ₄ ) ₂ —H ₂ O ₂ —Ba (OH) ₂ system, it was found that the precipitate contained titanium, oxygen, barium, and sulfur. Assuming that all the barium in the precipitate exists as barium sulfate (BaSO ₄ ), the atomic ratio between the remaining oxygen and titanium was determined to be approximately 2.5 (Ti: O≈2: 5). From this, it is estimated that titanium exists as titanium dioxide (TiO ₂ ).

  Considering the result of the composition analysis and the result of the X-ray diffraction analysis described above, amorphous titanium dioxide (amorphous titanium dioxide) is produced, which is a photocatalytic component that is active in NO photooxidation. Thus, a titanium oxide film containing amorphous titanium dioxide as a photocatalytic component can be formed. In addition, carbonates and barium sulfate coexist in these precipitates, but it is considered that the photocatalytic activity of amorphous titanium dioxide is remarkably inhibited by these coexisting substances from the measurement result of the photooxidation rate of NO. I can't. Since these crystalline coexisting substances are hardly water-soluble, they are not easily eluted even when they come into contact with water, and are considered to function as a binder that retains amorphous titanium dioxide and prevents elution. Therefore, according to the method for forming a titanium oxide film in which the titanium salt is titanium sulfate and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide, During the production, calcium sulfate, strontium sulfate, or barium sulfate is produced. And since this calcium sulfate, strontium sulfate, or barium sulfate functions as a binder of titanium oxide (titanium dioxide) without substantially reducing the photocatalytic ability of the titanium oxide film, it is difficult for titanium oxide to elute due to rain, etc. A highly durable titanium oxide film can be formed.

  As described above, according to the present invention, a transparent horizontal plate having excellent water permeability and high bending strength can be manufactured at low cost. In addition, the production cost can be reduced when a catalyst for removing NOx is applied to the transparent horizontal plate.

  As a result, such transparent horizontal plates can be used as a water-permeable surface material for sidewalks, parking lots, buildings, garages, parks, poolsides, hydrophilic facilities, etc., and are expected to expand to roads and public roads. Is done.

  The transparent horizontal plate provided with a photocatalyst can be more appropriately used as an environment-improving pavement material provided with a photocatalytic function in addition to water permeability.

It is process drawing explaining the manufacturing process of the translucent horizontal board of this invention. It is process drawing explaining the manufacturing process of the translucent horizontal board of this invention. It is process drawing explaining the manufacturing process of the translucent horizontal board of this invention. It is process drawing explaining the manufacturing process of the translucent horizontal board of this invention. It is process drawing explaining the manufacturing process of the translucent horizontal board of this invention. It is a particle size curve graph of the aggregate preferably used in the present invention. It is a diagram showing the relationship between the pel oxo titanate ion aqueous H ₂ O ₂ / Ti (molar ratio) and NO adsorption rate. It is a diagram showing the relationship between the pel oxo titanate ion aqueous H ₂ O ₂ / Ti (molar ratio) of NO light adsorption rate. It is the figure which showed NO adsorption | suction speed | velocity | rate for every alkali. It is the figure which showed the NO photo-oxidation rate for every alkali. It is the figure which showed the relationship between Ba (OH) ₂ / Ti (molar ratio) and NO adsorption | suction rate in barium hydroxide and a peroxotitanate ion aqueous solution. It is the figure which showed the relationship between Ba (OH) ₂ / Ti (molar ratio) and NO photo-oxidation rate in barium hydroxide and peroxotitanate ion aqueous solution. It is the figure which showed the X-ray-diffraction result of the deposit produced | generated by mixing alkaline aqueous solution and peroxotitanate ion aqueous solution.

Explanation of symbols

1: Yamato Sakura 2: Earthenware gravel 3: Aotama gravel 4: Tawa gravel No. 7 10: Block material filling process for base layer 20: Clamping process 30: Block material filling process for surface layer 40: Molding process 50: Demolding process 60: Curing process 61: Pre-curing process 62: Post-curing process 70: Surface treatment process 71: Catalyst application process 72: Surface processing process

Claims (19)

With a cement mixed with a polymer thickener as the main binder, a water-permeable surface layer in which aggregates having a particle size in the range of 1 mm to 10 mm and having an equality coefficient of less than 4 are joined together,
A cement binder mixed with a polymer thickener as a main binder includes a base layer in which aggregates having a particle diameter within a range of 1 mm to 10 mm and having an equality coefficient of less than 4 are joined together,
The surface layer and the base layer are bonded as a main binder cement mixed with a polymer thickener,
A permeable horizontal plate having a water permeability of 0.1 cm / second or more and a bending strength of 4 MPa or more.   The translucent horizontal plate according to claim 1, wherein the binder contains an anti-whitening agent, and the polymer thickener is an acrylic resin.   2. The transparent horizontal plate according to claim 1, wherein titanium oxide as a NOx removal catalyst is fixed to the surface side of the surface layer binder constituting the surface layer.   2. The transparent horizontal plate according to claim 1, wherein the surface layer has a thin layer mainly composed of titanium oxide as a NOx removal catalyst on the surface thereof.   5. The transparent horizontal plate according to claim 3, wherein the titanium oxide is derived from a reaction product of a peroxotitanate ion aqueous solution or a titanium salt aqueous solution and hydrogen peroxide. Cement C mixed with a polymer thickener, water (W) having a mass ratio (W / C) within the range of 0.20 to 0.35 with respect to the total mass of the cement C, and a particle diameter of 1 mm to 10 mm A surface layer aggregate having a uniformity coefficient of less than 4 and a surface layer block material, and
Cement C mixed with a polymer thickener, water (W) having a mass ratio (W / C) within the range of 0.20 to 0.35 with respect to the total mass of the cement C, and a particle diameter of 1 mm to 10 mm A base layer block material including a base layer aggregate having a uniformity coefficient of less than 4 in the range of
A base layer block material filling step of filling the base layer block material into the mold while applying vibration;
A mold clamping process in which a compressive force is applied to the filling and compacted immediately while applying vibrations after the filling process;
A surface layer block material filling step for filling the surface layer block material in the mold while applying vibration immediately after the mold clamping step;
A molding process in which a compressive force is applied to the filling while applying vibration immediately after the filling process,
In order, then
A method for producing a transparent horizontal plate, comprising performing a combination of a demolding step of demolding a molded product from a mold and a curing step of curing the molded product.   The method for producing a transparent horizontal plate according to claim 6, wherein the binder contains an anti-whitening agent, and the polymer thickener is an acrylic resin.   After the molding step and before the curing step, curing is performed after performing a titanium oxide application step for applying titanium oxide as a NOx removal catalyst that functions as a photocatalyst from the surface side. Item 7. A method for producing a transparent horizontal plate according to Item 6.   The method for producing a transparent horizontal plate according to claim 8, wherein the titanium oxide application step is a slurry application step of applying a predetermined amount of slurry containing titanium oxide.   In the titanium oxide application step, a titanium oxide film as a NOx removal catalyst that functions as a photocatalyst is obtained by using a peroxotitanate ion aqueous solution on the cement surface by utilizing the alkalinity possessed by the cement before the curing step. The method for producing a transparent horizontal plate according to claim 8, wherein the film forming step is a film forming step.   The titanium oxide application step uses the alkalinity possessed by the cement before the curing step to act on the cement surface with a titanium salt aqueous solution, and then acts on hydrogen peroxide to act as a photocatalyst for NOx removal catalyst. The method for manufacturing a transparent horizontal plate according to claim 8, wherein the titanium oxide film is formed as a film forming step.   The method for producing a transparent horizontal plate according to claim 6, further comprising a titanium oxide application step of applying titanium oxide as a NOx removal catalyst that functions as a photocatalyst from the surface side at an appropriate stage after the curing step.   The method for producing a transparent horizontal plate according to claim 12, wherein the titanium oxide application step is a slurry application step of applying a slurry containing titanium oxide.   The titanium oxide application step is a film formation step of forming a titanium oxide film as a NOx removal catalyst that functions as a photocatalyst by allowing peroxotitanate ions to act in the presence of an alkali. 13. A method for producing a transparent horizontal plate according to 13.   The titanium oxide application step includes (1) forming a titanium oxide film as a NOx removal catalyst that functions as a photocatalyst by acting an aqueous peroxotitanate ion solution in the presence of alkali, or (2) titanium 14. The transparent horizontal plate according to claim 13, which is a film forming step of forming a titanium oxide film as a NOx removal catalyst that functions as a photocatalyst by applying a hydrogen peroxide solution after the salt aqueous solution is applied. Production method.   The method according to claim 10 or 15, wherein the aqueous peroxotitanate ion solution is a mixed aqueous solution of a titanium salt aqueous solution and a hydrogen peroxide solution.   The method for manufacturing a transparent horizontal plate according to claim 11 or 15, wherein the titanium salt is titanium sulfate or titanium chloride.   The said alkali is any one of an alkali metal hydroxide, an alkaline-earth metal hydroxide, or ammonia, The manufacturing method of the translucent horizontal board of Claim 14 or 15 characterized by the above-mentioned.   The transmissive horizontal plate according to claim 18, wherein the titanium salt is titanium sulfate and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide. Production method.

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