JP2006273660A - Photocatalytic inorganic building material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocatalytic inorganic building material which is rich in decorativeness because the whole of it is thoroughly colored and which has both adsorbing performance and decomposing performance for a pollutant in air. <P>SOLUTION: The photocatalytic inorganic building material of this invention is obtained by dispersing a powdery inorganic pigment having photocatalytic performance in a base material of an inorganic building material composed of a porous body, and it provides an inorganic building material having both adsorbing performance and photocatalytic performance against a pollutant in air, and further it is capable of providing an inorganic building material being uniformly colored over the whole at a low cost, because the base material is uniformly colored due to the capability of the uniform dispersion of the powdery inorganic pigment from the surface to the inside of the base material of the inorganic building material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photocatalytic inorganic building material in which an inorganic pigment having photocatalytic performance is uniformly dispersed in an inorganic building material substrate.

In recent years, building structures have become highly airtight, and societal problems have arisen that volatile organic substances such as acetaldehyde and formaldehyde, ammonia with a strong off-flavor, etc., which are the cause of sick house syndrome, are generated. Therefore, it is necessary to adsorb pollutants in the air including bacteria and viruses, and a building material having a capability of adsorbing these substances is required as a building material constituting a building structure.
Here, as a method of adsorbing contaminants in the air, generally, an adsorbent is used. As the adsorbent, a porous body having many fine pores is used. As this porous body, for example, apatite, zeolite, activated carbon, silica gel, diatomaceous earth, anhydrous silica, calcium silicate and the like are known.

Of these, for example, calcium silicate, which is a porous body, is known as a non-combustible material, and since it is a lightweight and thermally stable substance, it is molded into molded bodies of various shapes and has adsorption performance. Widely used as a building material and heat insulation material. In general, this calcium silicate can be synthesized by room temperature curing or steam curing, but it is advantageous in terms of strength and dimensional stability to be performed under hydrothermal conditions. Also, a hydrothermal reaction is required in order to cause the siliceous raw material and the calcareous raw material to react to crystallize calcium silicate. Further, as a method of curing calcium silicate, a carbonation reaction is known in which it reacts with carbon dioxide gas to cure, and this carbonation reaction can fix carbon dioxide (CO ₂ ) gas such as exhaust heat. It also serves to suppress global warming due to carbon dioxide (CO ₂ ) emissions.

On the other hand, photocatalysts that have become a hot topic in recent years are capable of decomposing organic substances that are excited by ultraviolet rays or visible light and that are in contact with them. Therefore, the application of photocatalysts is effective as a solution to the above-mentioned social problems. The technological development of photocatalysts has been actively conducted. In addition, if a photocatalyst is applied to a building material based on a porous body, it is advantageous because the building material has both adsorption performance and decomposition performance.
Here, since the photocatalyst exhibits the catalytic performance only in the portion irradiated with light, when applying the photocatalyst to the porous body, it is sufficient that the photocatalyst exists only in the surface portion of the porous body. It is not necessary to mix even the inside that does not reach. Therefore, building materials in which a film in which the surface material of the base material and the photocatalyst are blended are formed on the surface of the base material (for example, Patent Document 1), and concrete structures having a surface layer portion as a photocatalyst-containing layer are widely used. Provided (for example, Patent Document 2).
On the other hand, when a photocatalyst layer is formed on a base material colored with a paint as a decoration, organic matter is blended with the paint, so if the photocatalyst is brought into direct contact with the paint layer made of paint, the paint layer is destroyed. There was a problem of being. Therefore, the structure which forms the photocatalyst layer after forming the layer which consists of an inorganic material on a coating material layer was employ | adopted (for example, patent document 3).

JP-A-7-113272 JP 2001-317199 A JP 11-319709 A

  However, as disclosed in Patent Document 1 and Patent Document 2, when a layer made of a photocatalyst is formed only on the surface layer of the base material, the photocatalyst may fall off due to wear on the surface, or the base material may be processed. In such a case, there has been a problem that a portion where the photocatalyst does not exist appears. In addition, as disclosed in Patent Document 3, in the case of adopting a configuration in which a photocatalyst layer is formed after forming an inorganic layer on a paint layer, in addition to the above-described problems. As a result, the manufacturing process becomes complicated due to the formation of a multilayer structure, and the formation of a coating layer on the surface causes problems in that the adsorption performance and humidity control performance of the base material cannot be exhibited.

  The object of the present invention has been made in view of the above circumstances, and is colored so that it has a high decorative property, and also has a photocatalytic inorganic building material that has both adsorption performance and decomposition performance of pollutants in the air. Is to be provided at a low cost.

  In order to achieve the above object, the photocatalytic inorganic building material of the present invention is characterized in that a powdery inorganic pigment having a photocatalytic performance is dispersed in a porous inorganic building material substrate. To do.

The photocatalytic inorganic building material of the present invention is formed by dispersing an inorganic pigment having photocatalytic performance in an inorganic building material base material composed of a porous body, while maintaining the mechanical characteristics of ordinary building materials. In addition, air pollutants (for example, volatile organic substances such as acetaldehyde and formaldehyde, ammonia, bacteria, viruses, etc.) may be referred to as adsorption performance by a substrate and decomposition performance by a photocatalyst (hereinafter referred to as “photocatalytic performance”). It is an inorganic building material (photocatalytic inorganic building pigment).
Further, since the inorganic pigment is in a powder form, the base material is uniformly colored by being able to uniformly disperse the inorganic pigment on the surface or inside of the base material of the inorganic building material, and on the coating layer. After the formation of the inorganic layer made of an inorganic material, it is not necessary to adopt a configuration for forming a photocatalyst layer, and an inorganic building material that is uniformly colored as a whole can be obtained at low cost.
Furthermore, by adopting a configuration in which an inorganic pigment having photocatalytic performance is dispersed in the base material, the photocatalyst is lost due to wear on the surface or the photocatalyst does not exist even when the base material is processed. The photocatalytic performance can be efficiently expressed from all aspects without the problem of appearing.

Examples of the inorganic pigment having such photocatalytic performance include iron oxide, tin oxide, tungsten oxide, and zirconium oxide.
In addition, as an inorganic building material substrate made of a porous material, for example, one or more materials selected from cement, siliceous material, calcareous material, slag (hot metal) and gypsum are used as a main raw material, and necessary. The material (for example, ceramics material etc.) which mixed and stiffened the fiber reinforcement is mentioned.

In the photocatalytic inorganic building material of the present invention, the content of the inorganic pigment is preferably 0.1 to 10.0% by mass with respect to the entire inorganic building material.
According to the present invention, the content of the powdered inorganic pigment dispersed in the inorganic building material substrate is 0.1 to 10.0% by mass with respect to the entire inorganic building material, so that the photocatalytic performance Is efficiently expressed and the cost is also improved.

In the photocatalytic inorganic building material of the present invention, the inorganic pigment is preferably in the form of powder, and the average particle size of the inorganic pigment is preferably 0.1 to 10.0 μm.
According to the present invention, since the average particle diameter of the inorganic pigment dispersed in the inorganic building material substrate is 0.1 to 10.0 μm, the inorganic pigment is more uniformly dispersed in the inorganic building material substrate. As a result, the entire base material is colored, and the photocatalytic performance of the photocatalytic inorganic building material is efficiently and reliably exhibited.

The photocatalytic inorganic building material of the present invention is formed by dispersing an inorganic pigment having photocatalytic performance in an inorganic building material base material composed of a porous body. As an inorganic pigment having such photocatalytic performance, Examples thereof include iron oxide (Fe ₂ O ₃ : red pigment), tin oxide (SnO ₂ : white pigment), tungsten oxide (WO ₃ : yellow pigment), zirconium oxide (ZrO ₂ : white pigment), and the like. Since these inorganic pigments are generally commercially available, they can be easily obtained. These inorganic pigments may be used individually by 1 type, and may be used in combination of 2 or more type.
In addition, about the color tone of these inorganic pigments, it is an illustration to the last, and if it is these inorganic pigments, even if a color tone is a little different, it shall treat as the same thing.

The form of these inorganic pigments having photocatalytic properties is used as a powder. In the present invention, by using such an inorganic pigment in powder form, it can be uniformly dispersed on the surface or inside of the inorganic building material, and the photocatalytic performance can be efficiently exhibited.
The “powdered form” mentioned here includes not only a general powder form but also a particle form.

The average particle size of the powdered inorganic pigment having photocatalytic performance is preferably 0.1 to 10.0 μm, particularly preferably 0.15 to 1.0 μm. When the average particle diameter of the inorganic pigment is in the range of 0.1 to 10.0 μm, the inorganic pigment is more uniformly dispersed in the base material of the inorganic building material, and the specific surface area is also appropriate. Thus, the photocatalytic performance of the photocatalytic inorganic building material is surely exhibited. Moreover, coloring will also be given to the whole base material and decorativeness will also become favorable.
On the other hand, when the average particle size of the inorganic pigment is smaller than 0.1 μm, handling becomes difficult, while when the average particle size exceeds 10.0 μm, the dispersibility in the substrate is deteriorated and the coloring state is deteriorated. In addition to being biased, it may adversely affect the photocatalytic performance.

  The content of the inorganic pigment having photocatalytic performance in the photocatalytic inorganic building material of the present invention is preferably 0.1 to 10.0% by mass with respect to the entire photocatalytic inorganic building material, 0.5 to It is especially preferable to set it as 5.0 mass%. When the content of the inorganic pigment is less than 0.1% by mass, the photocatalytic performance may not be exhibited, and the coloring effect on the substrate may not appear. On the other hand, when the content is more than 10.0% by mass, although the photocatalytic performance and the coloring effect are exhibited, the photocatalytic inorganic building material of the present invention is expensive because the inorganic pigment is originally expensive. Therefore, it is not preferable in terms of cost.

  The photocatalytic inorganic building material of the present invention is obtained by dispersing such an inorganic pigment in an inorganic building material substrate made of a porous material, and is applied to the inorganic building material substrate applied to the present invention. Examples of such materials include ceramic materials. Such ceramic materials are generally used as building interior materials, ceiling materials, partition walls, building exterior materials and the like because they can suppress corrosion and insect damage and are excellent in durability.

Ceramic materials are generally made of one or more materials selected from cement, siliceous materials, calcareous materials, slag (hot metal) and gypsum, and mixed with fiber reinforcements as necessary. After being formed into a predetermined shape, it is obtained as a porous body through a curing process such as hydrothermal curing, steam curing, and normal temperature and normal pressure curing. The ceramic material is characterized by being porous and light in specific gravity, and can exhibit excellent strength, and is excellent in workability and transportability.

The siliceous material refers to, for example, a raw material containing silicic acid (SiO ₂ ), for example, mineral fine powder such as quartzite, quartz sand, diatomaceous earth, white clay, perlite, fly ash, silica fume and the like. Dust can be used.
As the calcareous material, for example, quick lime, slaked lime, slaked lime milk obtained by digesting quick lime with water or warm water, calcium carbonate, and the like can be used.

  As the fiber reinforcing material, organic and inorganic fiber reinforcing materials can be used. Cellulose fibers (including kraft pulps such as softwood bleached kraft pulp (NBKP) and hardwood bleached kraft pulp (LBKP)), polypropylene fibers, and aramid fibers can be used as the organic fiber reinforcing material. As the inorganic fiber reinforcing material, glass fiber, stainless fiber or the like can be employed.

An example of the method for producing the photocatalytic inorganic building material of the present invention will be described.
For example, when calcium silicate is used as a base material, first, a predetermined inorganic pigment is added to a mixture of cement, siliceous material, calcareous material, fiber reinforcing material, etc., which becomes an inorganic building material base material. A mixed material of an inorganic pigment and an inorganic building material substrate is obtained. Water is added to the mixed material to prepare a kneaded product having gel fluidity.

Next, the kneaded product is formed into a molded body by a predetermined molding method. Examples of the molding method include extrusion molding and dehydration press molding.
Here, when extrusion molding is used, it is less affected by non-uniformity due to the difference in specific gravity of each raw material in the kneaded product, and the inorganic pigment can be easily molded in a uniformly mixed state. In addition, the shape of the molded body can be applied to various building members such as a peripheral edge, parting edge, and window frame as well as a flat plate, and a building member having a predetermined shape that is rich in design can be formed.

  In the case of dehydration press molding, since the difference in specific gravity of each raw material is small in a gel-like kneaded product, each raw material can be uniformly mixed and molded similarly to extrusion molding. Moreover, in this dehydration press molding, by providing a pattern on the press surface, it is possible to obtain a building material having a pattern surface on the surface and further rich in decorativeness.

Further, water may be further added to the gel-like kneaded material to form a slurry, which may be formed by papermaking.
Here, when performing paper-molding etc., it is preferable to add a flocculant at the time of the shaping | molding. The inorganic pigment having photocatalytic performance used in the present invention is filtered together with filtered water, and there is a problem that the entire amount does not remain in the molded body. In addition to being able to uniformly disperse the inorganic pigment with respect to the base material, it is possible to prevent the inorganic pigment from flowing out during papermaking and to improve the moldability, which is preferable.

As the aggregating agent, it is preferable to use a polymer aggregating agent such as a polyacrylamide-based cationic polymer aggregating agent, and if necessary, an inorganic aggregating agent such as aluminum sulfate or polyaluminum chloride (PAC) is used in combination. May be.
The amount of the flocculant added is preferably 0.1 to 5 parts by weight, particularly 0.5 to 3 parts by weight, based on 100 parts by weight of the solid content of the inorganic building material substrate. preferable. When the addition amount of the flocculant is in the range of 0.1 to 5 parts by weight, the agglomeration is suitably performed, whereas when the addition amount of the flocculant is less than 0.1 part by weight of the solid content, the aggregation is not performed well. In addition, if the amount exceeds 5 parts by weight, more than necessary agglomeration may occur, and the cost is increased.

The molded body thus obtained is cured by curing. Examples of the curing method include hydrothermal curing, steam curing, normal temperature and normal pressure curing, and the like. By performing this curing, in the presence of water, the cement hydration reaction, the bonding reaction between the siliceous material and the calcareous material proceeds, the molded body is cured, and from the porous body excellent in strength and dimensional stability. It becomes a formed product.
In addition, since the synthesized calcium silicate has large voids, it can exhibit adsorptivity, humidity control, light weight, and heat insulation, so even if the adsorption performance is further improved, a large amount of adsorbent is required. It is also preferable in that it does not.
In addition, what is necessary is just to select a curing method suitably according to the environment where a molded object is used from a viewpoint of costs, such as energy cost and maintenance of apparatus equipment.

  In addition, as an inorganic building material substrate made of a porous material, for example, when calcium carbonate as disclosed in JP-A-9-183617 is used as a substrate, calcium carbonate powder, fiber reinforcing material, photocatalytic performance After blending a binder as an auxiliary agent and a mixed material to form a mixed material, if the photocatalytic inorganic building material of the present invention is molded using the same method as the case of using calcium silicate as a base material, Good. Here, in order to accelerate the curing of the molded body, a binder may be added as an auxiliary agent, but a binder as an auxiliary agent is not added. For example, the production disclosed in JP-A-2003-89568 The method may be used as appropriate.

The thus obtained photocatalytic inorganic building material of the present invention is formed by dispersing a powdery inorganic pigment having photocatalytic performance in a porous inorganic building material base material. In addition to being an inorganic building material that combines adsorption performance with the base material and photocatalytic performance, the base material is uniformly colored by dispersing the pigment in the base material, and the whole is uniformly colored. Inorganic building materials can be obtained at low cost.
In addition, by adopting a configuration in which an inorganic pigment having photocatalytic properties is dispersed in the base material, the photocatalyst is dropped due to wear on the surface, or a portion where the photocatalyst does not exist even when the base material is processed. Without any problem of appearing, photocatalytic performance can be efficiently expressed from all sides.

In addition, according to the photocatalytic inorganic building material of the present invention, a material having mechanical properties comparable to conventional inorganic building materials (not having photocatalytic performance) can be obtained as inorganic building materials. For example, an inorganic building material having a bulk specific gravity of 1.1 or less, a bending strength of 10.0 N / mm ² or more, and a water absorption length change rate of 0.15% or less can be obtained.

  The aspect described above shows one aspect of the present invention, and the present invention is not limited to the above-described embodiment, and is within the scope of achieving the object and effect of the present invention. Needless to say, modifications and improvements are included in the content of the present invention. Further, the specific structure, shape, and the like in carrying out the present invention are not problematic as other structures, shapes, and the like as long as the objects and effects of the present invention can be achieved.

For example, in the above-described embodiment, a predetermined method is exemplified and described as a method for producing a photocatalytic inorganic building material. However, the present invention is not limited thereto, and the photocatalytic inorganic building material of the present invention is obtained by any means. There is no problem in doing so.
In addition, the photocatalytic inorganic building material of the present invention includes a conventionally known inorganic pigment that does not have photocatalytic performance, such as chromium oxide (green pigment), hydrous iron oxide ( Yellow pigment), carbon (black pigment), etc. may be added.
Moreover, you may add thickeners, such as methylcellulose.
In addition, the specific structure, shape, and the like in the implementation of the present invention may be other structures as long as the object of the present invention can be achieved.

  EXAMPLES Next, although an Example and a reference example are given and this invention is demonstrated further in detail, this invention is not restrict | limited at all to description content, such as these Examples.

[Examples 1 and 2 and Reference Example 1]
Using the raw materials shown below at the blending ratio shown in Table 1, a building material substrate containing a powdery inorganic pigment (colored inorganic pigment) having photocatalytic performance by the following manufacturing method was used. A plate material (Examples 1 and 2), which is a photocatalytic inorganic building material, and a plate material (Reference Example 1) containing no inorganic pigment as a control were produced.

(Raw materials used)
Cement: Ordinary Portland cement Silica sand (silica powder): SiO ₂ content 97.8% by mass
(Blaine specific surface area 5000 cm ² / g)
Fiber reinforcement: Softwood bleached kraft pulp (NKBP) and polypropylene fiber
Made of fiber (mixing ratio 1: 1)
Methylcellulose: Water-soluble methylcellulose (as a thickener)
Pearlite: Pearlite JIS S0.15-0.6
Inorganic pigment 1: Titanium oxide (TiO ₂ anatase type)
(Powder. Average particle size 0.18 μm)
Inorganic pigment 2: Iron oxide (Fe ₂ O ₃ ) (powder, average particle size 0.5 μm)

(Combination ratio of materials used)

(Manufacturing method of plate material)
According to the composition shown in Table 1, each raw material used and water were mixed to obtain a mixed material, and then kneaded for 10 minutes at a stirring rotation speed of 50 rpm using a commercially available mortar mixer to obtain a kneaded product.
And the obtained kneaded material was extrusion-molded with a commercially available extruder, and a plate material having a length of 450 mm × width of 300 mm × thickness of 12 mm was obtained.

  Next, the obtained plate was subjected to hydrothermal treatment (hydrothermal curing) for 10 hours under conditions of a pressure of 0.49 MPa (5 kgf) and a temperature of 151 ° C., and then dried at 120 ° C. for 12 hours to obtain a photocatalytic inorganic A plate material that is a building material was obtained.

[Test Example 1]
In order to confirm the performance as a building material for the plate materials obtained in Examples 1 and 2 and Reference Example 1, according to the following evaluation conditions, “bulk specific gravity” “bending strength” “water absorption rate” and “water absorption length” "Change rate" was measured and compared. In addition, “appearance” and “cutability” were also confirmed and compared and evaluated. The results are shown in Table 2.

(Bulk specific gravity)
Measured according to JIS A5430 (n = 3).

(Bending strength)
It measured based on JIS A1408 (n = 3).

(Water absorption rate)
Measured according to JIS A5430 (n = 3).

(Change rate of water absorption length)
Measured according to JIS A5430 (n = 3).

(appearance)
The appearance of the obtained plate material was visually observed and confirmed. The case where there was no abnormality in the appearance was determined as “◯”, the case where it was normal, “Δ”, and the case where the appearance was warped was determined as “X”.

(Cutability)
The obtained plate material was cut with a tip saw (outer diameter 355 mm), and the linearity of the cut surface was visually observed and confirmed. Then, the case where the cut surface was good was determined as “◯”, the case where it was normal, “Δ”, and the case where the cut surface was bent was determined as “X”.

(Evaluation results)

  As can be seen from the results in Table 2, the plate materials obtained in Examples 1 and 2 were cured well during production as in Reference Example 1 which did not contain a color pigment having photocatalytic performance, and had excellent bending strength. It turns out that is expressed. Further, the rate of change in water absorption length was low, and the product had sufficient dimensional stability against water absorption. And the external appearance and cutting workability were also favorable. From the above, it was confirmed that there was no problem even if it was used as a building material.

[Test Example 2]
Measurement of photocatalytic performance:
The photocatalytic performance of the plate material obtained in Example 1 was evaluated. Specifically, it was confirmed by the following method in accordance with “Method for testing wet decomposition performance in photocatalyst product” disclosed in the photocatalyst product forum (http://www.photocatalyst.gr.jp/).

(1) Pre-processing:
In this method, the plate material of Example 1 was cut into a size of 50 mm × 50 mm to obtain a test sample, cells were fixed on the test surface of the test sample, and pretreatment was performed as follows.
As an adsorbing solution, 20 ppm of methylene blue solution was injected into a 30 ml test sample and adsorbed. When the absorbance of this methylene blue solution was higher than that of 5 ppm of a separately prepared methylene blue test solution, the pretreatment was completed. On the other hand, when the absorbance was lower than that of the methylene blue test solution, a new 20 ppm of methylene blue adsorbed solution was used and again adsorbed for 12 hours to measure the absorption spectrum. This was continued until the absorbance was higher than that of 5 ppm of the methylene blue test solution. The absorbance was measured with a spectrophotometer, and the measurement wavelength was fixed at 664 nm.
In this way, the absorption spectrum of the methylene blue test solution was measured and used as the initial absorption spectrum.

(2) Test (no ultraviolet (UV) irradiation):
When the pretreatment of (1) is completed, 30 ml of 5 ppm methylene blue test solution is injected into the test sample, and the absorbance after 1 hour is measured. Then, the liquid used for the measurement is immediately returned to the test cell and adsorbed again. With such a procedure, the absorbance was measured every hour for a total of 3 hours. Since the absorbance is proportional to the concentration, the concentration of the methylene blue test solution was calculated from a calibration curve prepared in advance.

(3) Test (ultraviolet (UV) irradiation):
Further, after completion of the measurement of (2), the methylene blue test solution was taken out, 30 ml of a new methylene blue test solution 5 ppm was injected, irradiated with ultraviolet rays of 1.0 ± 0.05 mW / cm ² for 1 hour, and the absorbance was measured. Then, the liquid used for the measurement is immediately returned to the test cell and irradiated again. In such a procedure, the absorbance was measured every hour for a total of 3 hours, and the concentration was calculated in the same manner as in (2) without ultraviolet (UV) irradiation. The relationship between the elapsed time and the methylene blue test solution concentration in the above (2) and (3) is shown in FIG.

As can be seen from the results in FIG. 1, it can be seen that the test sample (Example 1) has a methylene blue test solution that is irradiated with ultraviolet rays (UV), and that the concentration drop is faster than that without UV irradiation. It was confirmed that it had performance.
Moreover, FIG. 1 shows that the density | concentration fall in the test sample which is not irradiated with an ultraviolet-ray is also large. From this, the plate material (photocatalytic inorganic building material) obtained in Example 1 is capable of decomposing with a photocatalyst once adsorbing odors etc. in the air and then adsorbing odors etc. It could be confirmed.

[Test Example 3]
Evaluation of photocatalytic performance (confirmation of acetaldehyde decomposition performance):
The acetaldehyde removal performance of the plate material obtained in Example 1 was confirmed by the following procedure.
The plate material obtained in Example 1 was cut into a size of 10 cm × 10 cm to obtain a test sample. After putting a test sample in a plastic circulation container with a capacity of 1.0 L filled with 0.6 L of acetaldehyde gas of known concentration, the test tube is irradiated every 15 minutes for 60 minutes with an ultraviolet intensity of 1.5 mW / m ^2. Was used to measure the acetaldehyde concentration and confirm the adsorptive decomposition performance. The results are shown in FIG.
In this test, since acetaldehyde (CH ₃ CHO) is considered to be decomposed into carbon dioxide (CO ₂ ), the CO ₂ concentration after 60 minutes from the start of the test was also measured with a detector tube. The results are shown in Table 3.

(result)

As can be seen from the results in FIG. 2, acetaldehyde was adsorbed and removed by the test sample immediately after the start of the test (from the start of the test to 15 minutes), and a decrease in the acetaldehyde concentration in the container was observed with the passage of time.
Further, as can be seen from the results in Table 3, the concentration of carbon dioxide after 60 minutes from the start of the test is 680 ppm with respect to the CO ₂ concentration (400 ppm) in the container at the start of the test, and carbon dioxide is generated. From this, it can be seen that acetaldehyde was simultaneously decomposed into carbon dioxide by ultraviolet irradiation.
Thus, it has confirmed that the board | plate material (photocatalytic inorganic building material) of Example 1 was equipped with the decomposition | disassembly performance of acetaldehyde.

  The photocatalytic inorganic building material of the present invention can be widely used as various building materials such as building interior materials, ceiling materials, partition walls, and building exterior materials.

5 is a graph showing the relationship between elapsed time and methylene blue test solution concentration in Test Example 2. It is the graph which showed the relationship between the time passage in Test Example 3, and the density | concentration change of the acetaldehyde in a container.

Claims (3)

  A photocatalytic inorganic building material obtained by dispersing a powdery inorganic pigment having photocatalytic performance in an inorganic building material substrate made of a porous material. In the photocatalytic inorganic building material according to claim 1,
Content of the said inorganic pigment is 0.1-10.0 mass% with respect to the whole inorganic building material, The photocatalytic inorganic building material characterized by the above-mentioned. In the photocatalytic inorganic building material according to claim 1 or 2,
A photocatalytic inorganic building material, wherein the inorganic pigment has an average particle size of 0.1 to 10.0 μm.

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