Cement product for air purification

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an air purification cement product, and more particularly, the present invention relates to an air purification cement product in which efflorescence is prevented, acid resistance is good, and an excellent air purification function is maintained. Is.

【0002】

[Conventional technology]

In recent years, air purification products have been developed that remove harmful substances in the atmosphere (for example, NOx, SOx, HC (hydrocarbon), etc.) by utilizing the photocatalytic reaction of titanium oxide. These products are mainly composed of cement, titanium dioxide powder and sand, and are cement tiles for outer walls, blocks, cement boards, blocks for pavement and the like. Among these, Portland cement is usually used as the cement in consideration of economic efficiency, air purification efficiency, and the like.

【0003】

[Problems to be Solved by the Invention]

However, cement as described above is preferable in that it is inexpensive and economical, but products manufactured using such cement are associated with the hydration reaction of cement and the hydration reaction component of cement ( (Slaked lime, calcium carbonate, etc.) elutes to generate so-called efflorescence, which coats the surface of titanium oxide present on the surface of the product. As a result, titanium oxide is not exposed to sufficient ultraviolet light and harmful substances in the atmosphere cannot come into contact with the surface of titanium oxide, so that sufficient photocatalytic reaction does not proceed, and by extension, such air purification products remove harmful substances. It had the drawback that efficiency declined over time.

【0004】

Therefore, the present inventors have made various studies from the viewpoint of preventing efflorescence generated by the hydration reaction of cement and from the viewpoint of suppressing the ingress of water, which is a factor in the generation of efflorescence. Since monocalcium aluminate (CA) is the main constituent mineral, we found that it does not generate calcium hydroxide by hydration reaction, and it is even better to combine it with a waterproof material that prevents the ingress of water. We have found that the effect of preventing efflorescence can be obtained, and as a result, we have obtained a cement product for air purification that not only has excellent removal efficiency of harmful substances but also does not reduce the removal efficiency of harmful substances over time. ..

【0005】

Therefore, an object to be solved by the present invention is to provide an excellent alumina cement product for air purification, which has excellent removal efficiency of harmful substances and whose removal efficiency of harmful substances does not decrease with age.

【0006】

[Means for solving problems]

The above object of the present invention is achieved by each of the following inventions.

【0007】

(1) A cement for air purification, which comprises 100 parts by weight of alumina cement, 5 to 50 parts by weight of titanium oxide, 100 parts by weight to 700 parts by weight of aggregate, and 20 to 200 parts by weight of water. Product. (2) The cement product for air purification according to the above item 1, wherein 10 to 200 parts by weight of a pozzolan substance is added to 100 parts by weight of alumina cement. (3) The cement product for air purification according to the above item 1 or 2, wherein the kneaded product has a waterproof material. (4) An air purification cement product characterized in that a waterproof material is applied to the surface of the air purification cement product according to the first or second item. (5) The cement product for air purification according to the above item 3 or 4, wherein the waterproof material is a silicone compound.

【0008】

The air purification cement product of the present invention comprises a kneaded product containing 100 parts by weight of alumina cement, 5 to 50 parts by weight of titanium oxide, 100 parts by weight to 700 parts by weight of aggregate and 20 to 200 parts by weight of water. By using alumina cement, it is possible to obtain an excellent cement product for air purification whose air purification performance is improved and whose air purification performance is maintained over time. Further, in the present invention, 10 to 200 parts by weight of the pozzolan substance is added to 100 parts by weight of the alumina cement, but the addition of the pozzolan substance does not maintain the performance as a binder and deteriorate the air purification performance. Further, in the present invention, the kneaded product contains a waterproof material to prevent efflorescence, and as a result, the air purification performance is further improved and the maintenance of the air purification performance over time is excellent. Further, when this kneaded product is made into a product by molding or the like, a waterproof material may be applied to the surface thereof. Especially when the waterproof material is a silicone compound, the maintenance of air purification performance over time is excellent.

【0009】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

【0010】

The air purification cement product of the present invention comprises a kneaded product containing 100 parts by weight of alumina cement, 5 to 50 parts by weight of titanium oxide and 100 parts by weight to 700 parts by weight of aggregate. Alumina cement is a bauxite or van. It is a type of special cement produced by melting or condensing alumina-based raw materials such as bauxite and limestone. Since this alumina cement contains monocalcium aluminate (CA) as the main component, it not only does not produce calcium hydroxide by hydration reaction, but also has ultra-fast strength and strength that can withstand practical use in a few hours. It has the characteristics of developing and curing in one day, and has excellent characteristics that contribute to shortening the curing period of cement products. In addition, alumina cement has high chemical resistance to acids up to a low pH value (pH of about 4) such as sulfate, and contributes to the sustainability of air purification performance in that it does not deteriorate due to acid rain. Further, in the present invention, a pozzolan substance may be added to the alumina cement as described later, and preferred pozzolan substances include blast furnace slag, fly ash, silica fine powder and the like. The amount of the pozzolanic substance added to the alumina cement is preferably 10 to 200 parts by weight with respect to 100 parts by weight of the alumina cement.

【0011】

As the titanium oxide used in the present invention, titanium dioxide is particularly preferable, and either rutile or anatase crystal form may be used, but anatase-type titanium dioxide having high activity is preferable. Further, these titanium dioxides may contain titanium dioxide as a main component and a smaller amount of titanium oxide. It is also preferable to use metatitanic acid. Hereinafter, these are collectively referred to as titanium oxide. More preferably, chemically bonded water and / and hydrophilic OH ions and / and sulfate ions are present on the surface of titanium oxide, and the surface area of this titanium dioxide is 100 to 300 m.²/ g. This specific surface area is 100m²If it is smaller than / g, NOx absorption performance is poor, and therefore purification performance is poor. This specific surface area is 300m²If it exceeds / g, the dispersibility in cement deteriorates, and as a result, the purification performance deteriorates.

【0012】

The aggregate used in the present invention is preferably a fine aggregate, and the fine aggregate may be any sand such as natural sand or artificial sand. In addition, one or more of granite, silica stone, lightweight aggregate, glass grain or silica sand can be selected instead of sand. The particle size of these products is preferably 1.2 to 5 mm. However, in the present invention, in order to allow ultraviolet light to penetrate deep into the surface layer of the block to improve purification and absorption efficiency, a part of the sand is an aggregate having good light transmission (hereinafter, also referred to as a light transmitting aggregate). As the light-transmitting aggregate, glass beads, glass powder, silica sand, etc. can be used, and the particle size of the glass beads, glass powder, and silica sand is preferably 1 to 6 mm in diameter, and these light-transmitting aggregates. If the particle size of the aggregate is larger than this, the portion where the cement does not exist becomes large and the strength decreases. Further, if the particle size of the light-transmitting aggregate is smaller than this, the light transmission becomes poor.

【0013】

When a part of the sand is replaced with a light-transmitting aggregate such as glass beads or glass powder or silica sand, the amount thereof is preferably 10 to 50% by weight, more preferably 15 to 50% by weight of the total amount of the aggregate. Yes, 20-50% by weight is more preferred. If the amount of the light-transmitting aggregate is less than 10% by weight, the effect of light transmission does not appear, and if it is more than 50% by weight, the amount of sand is reduced and the strength of the product is lowered.

【0014】

Further, the present invention is characterized in that the kneaded product has a waterproof material, and within the scope of the claims of the present application, "the kneaded product has a waterproof material" means an alumina cement product for air purification. This includes a case where a waterproof material is added and mixed in the kneaded product which is a raw material for producing the above, and a case where the waterproof material is present on the surface of the air purification cement product by coating or impregnation. The waterproof material used in the present invention is not particularly limited as long as it does not adversely affect the air purification performance, but specifically, a fat-based, natural resin-based or synthetic resin-based waterproof material is used. Can be mentioned. The synthetic resin-based waterproof material is an acrylic-based, ester-based, urethane-based, epoxy-based, silicone-based, or a mixture of these waterproofing materials, and any of water-based and solvent-based is preferable, and silicone is more preferable. It is a waterproof material. Examples of the silicone-based waterproof material include silane-based, siloxane oligomer-based, modified alkoxysiloxane-based, polysiloxane-based, and siliconate-based waterproof materials.

【0015】

Examples of the siliconate-based waterproof material preferably used in the present invention include Polency (PoLenC, Shin-Etsu Chemical Co., Ltd.), TSW870 (Toshiba Silicone Co., Ltd.) and the like. Examples of the silane-based (monomer, oligomer) waterproof material include Enaseal (Earth Shokai), Aquaseal 200S (Sumitomo Seika Chemical Co., Ltd.), Toss Barrier 100, Toss Barrier 200 (Toshiba Silicone Co., Ltd.) and the like. Examples of the silicone resin-based waterproof material include TSW810 (Toshiba Silicone Co., Ltd.), PolonA (Shin-Etsu Chemical Co., Ltd.), Dry Seal L (Toray Dow Corning Silicone Co., Ltd.), Aqua Seal 30E (Sumitomo Seika Chemical Co., Ltd.), and the like. Other acrylic resin-based waterproof materials include Conceal CM-R (Fujikura Kasei Co., Ltd.), and other organic resin-based waterproof materials include Polon MF-40 (Shin-Etsu Chemical Co., Ltd.) and Water Seal # 101 (Japan). Special Paint Co., Ltd.), Pidrotherm (Nippon Chemix Co., Ltd.), etc.

【0016】

The amount of the waterproof material added to the kneaded product of the cement product for air purification of the waterproof material used in the present invention is 0.1 part by weight to 5.0 parts by weight, preferably 0.5 part by weight, based on 100 parts by weight of the kneaded product. It is 2 to 2 parts by weight. When the amount of this waterproof material added is less than 0.1 parts by weight, it does not contribute to the improvement of air purification performance as well as the waterproof effect. If the amount of the waterproof material added exceeds 5.0 parts by weight, the hydration reaction of the alumina cement is inhibited and sufficient curing cannot be obtained. Further, when applied to the surface of the product, a thick waterproof film is formed on the surface, the contact between harmful substances in the air and titanium oxide is cut off, and good air purification performance cannot be obtained.

【0017】

In the present invention, when producing a cement product for air purification, an admixture can be added to the kneaded product, and a pozzolan substance is usually used as the admixture, for example, blast furnace slag, fly ash, silica fine. Examples thereof include powder, natural pozzolan, silica shoem, etc., and the amount of this addition is preferably 10 to 200 parts by weight of the pozzolan substance with respect to 100 weight of alumina cement, that is, the amount of alumina cement that does not lose its performance as a binder, and is in this range. If the amount is added, the performance as a binder is not lost and the air purification performance is not affected. In addition, an adsorptive substance such as activated carbon can be added. The air purification cement product of the present invention preferably includes tiles for building materials, blocks, cement boards, tiles for pavement, blocks, concrete for pavement, blocks for rivers and shore protection, blocks for wave protection and the like.

【0018】

[Action] Since the cement product for air purification of the present invention uses alumina cement, it does not cause efflorescence, has quick strength, and has excellent acid resistance. Therefore, It is excellent in improving air purification performance and maintaining it over time.

【0019】

[Example]

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

【0020】

[Example 1] Alumina cement (Asahi Fonju (trade name), manufactured by Asahi Glass Co., Ltd.) 100 parts by weight, titanium oxide (for photocatalyst, anatase type, specific surface area 170 m)²/ g) 20 parts by weight of aggregate, 320 parts by weight of aggregate (fine aggregate, mountain sand from Ibaraki prefecture, coarse grain ratio 1.90) and 30 parts by weight of water were mixed to prepare a kneaded product having a mortar composition. Then, using the kneaded product having this mortar composition, a mortar molded product having a size of 10 × 10 × 0.5 (thickness) cm was produced by a one-layer pressure molding method. Molding pressure is 100kg / cm²I went there. After two weeks of moist air curing, it was dried at 60 ° C for 24 hours, and then the NOx purification performance was measured with a NOx purification performance measuring device. After the measurement, the test piece was exposed to the outdoors, and the NOx purification performance after the exposure time of 1 month, 3 months, 6 months and 1 year was measured. The results obtained are shown in Table 1.

【0021】

[Example 2] To the kneaded product having the mortar composition produced in Example 1, a waterproof material (silicone-based water repellent; BY16-601, manufactured by Toray Dow Corning Co., Ltd.) was added by 1.0 part by weight to 100 parts by weight of cement. After mixing, a test piece was prepared in the same manner as in Example 1, and the NOx purification performance was measured in the same manner. The results obtained are shown in Table 1.

【0022】

[Example 3] A test piece was prepared in the same manner as in Example 1 using a kneaded product having a mortar composition produced in the same manner as in Example 1. The surface of this test piece was coated with the waterproof material used in Example 2, and the NOx purification performance was measured in the same manner. The results obtained are shown in Table 1.

【0023】

[Examples 4 to 6] Half the amount of 100 parts by weight of alumina cement of Example 1 is blast furnace slag fine powder (manufactured by Mitsubishi Materials Corporation, powder degree 4500 cm).²/ g), fly ash (manufactured by Denki Kogyo), silica fine powder (powder degree 4880 cm)²/ G, made by Fujisaka Quartz Sand) were replaced with each other to prepare a kneaded product having three types of mortar composition. A test piece was prepared in the same manner as in Example 1, and the NOx purification performance was measured in the same manner. The results obtained are shown in Table 1.

【0024】

[Comparative Example 1] A test piece was prepared in the same manner as in Example 1 except that ordinary Portland cement was used instead of the alumina cement of Example 1. The obtained test piece was tested by the method used in Example 1 to measure the NOx purification performance. The results obtained are shown in Table 1.

【0025】

[Comparative Example 2] A test piece was prepared in the same manner as in Example 1 except that white cement was used instead of the alumina cement of Example 1. The obtained test piece was tested by the method used in Example 1 to measure the NOx purification performance. The results obtained are shown in Table 1.

【0026】

[Comparative Example 3] A test piece was prepared in the same manner as in Example 1 except that white cement was used instead of the alumina cement of Example 2. The obtained test piece was tested by the method used in Example 1 to measure the NOx purification performance. The results obtained are shown in Table 1.

【0027】

[Comparative Example 4] A test piece was prepared in the same manner as in Example 1 using white cement instead of the alumina cement of the kneaded product having a mortar composition produced in the same manner as in Example 3. The surface of this test piece was coated with the waterproof material used in Example 2, and the NOx purification performance was measured in the same manner. The results obtained are shown in Table 1.

【0028】

[table 1]

<img file="JPH11171630A_D0001.tif" />【0029】

[Effect of the invention]

The air purification cement product of the present invention comprises a kneaded product containing 100 parts by weight of alumina cement, 5 parts by weight to 50 parts by weight of titanium oxide, and 100 parts by weight to 700 parts by weight of aggregate. An excellent cement product for air purification can be obtained in which the purification performance is improved and the air purification performance is maintained over time. Further, since the kneaded product used in the present invention contains a waterproof material, the air purification performance is further improved and the maintenance of the air purification performance over time is excellent. Especially when the waterproof material is a silicone compound, the maintenance of air purification performance over time is excellent.