JPH11171630A - Cement product for air purification - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an excellent cement product for air purification, excellent in removal efficiency of a harmful substance and not causing lowering of removal efficiency of the harmful substance with year. SOLUTION: This cement product comprises a kneaded material containing 100 pts.wt. alumina cement, 5-50 pts.wt. titanium oxide, 100-700 pts.wt. aggregate and 20-200 pts.wt. water. In the cement product, 10-200 pts.wt. pozzolan substance may be added to 100 pts.wt. alumina cement. Further, a waterproof material may be contained in the kneaded material and the waterproof material may be mixed into the kneaded material or applied to the surface of the product obtained from the kneaded material. A silicone compound is preferable as the waterproof material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cement product for air purification, and more particularly, to the present invention, in which the efflorescence is prevented, the acid resistance is good, and an excellent air purification function is maintained. The present invention relates to an air purification cement product.

[0002]

2. Description of the Related Art In recent years, harmful substances (for example, NOx, SOx, HC
(Hydrocarbons) have been developed. These products are mainly cement,
It is made of titanium dioxide powder and sand, and is a cement tile, a block, a cement board or a pavement block for an outer wall. Among them, Portland cement is generally used as the cement in consideration of economy, air purification efficiency, and the like.

[0003]

However, the above-mentioned cement is preferable in that it is inexpensive and economical, but products manufactured using such cement are not suitable for the hydration reaction of cement. Along with this, the hydration reaction components (slaked lime, calcium carbonate, etc.) of the cement are eluted, so-called efflorescence occurs, and coats the surface of the titanium oxide present on the surface of the product. As a result, sufficient ultraviolet light is not applied to the titanium oxide, and at the same time, the harmful substances in the air cannot be brought into contact with the surface of the titanium oxide. Therefore, a sufficient photocatalytic reaction does not proceed. It has the disadvantage that the efficiency decreases over time.

Accordingly, the present inventors have conducted various studies from the viewpoint of preventing efflorescence generated due to the hydration reaction of cement and from the viewpoint of suppressing the ingress of water which is a factor of the generation of efflorescence. Alumina cement is monocalcium aluminate (CA)
Is a major constituent mineral, so we found that we did not generate calcium hydroxide by the hydration reaction, and even more excellent efflorescence prevention effect was obtained by combining it with a waterproof material that prevents water from entering. As a result, an air purification cement product that not only has excellent harmful substance removal efficiency but also does not decrease over time has been obtained.

Accordingly, an object of the present invention is to provide an alumina purification product for air purification which has an excellent harmful substance removal efficiency and which does not decrease with time. is there.

[0006]

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

(1) 100 parts by weight of alumina cement, 5 to 50 parts by weight of titanium oxide, 100 to 7 parts by weight of aggregate
An air purification cement product comprising a kneaded material containing 00 parts by weight and 20 to 200 parts by weight of water. (2) Pozzolanic substance 1 in 100 parts by weight of alumina cement
2. The air purifying cement product according to claim 1, wherein 0 to 200 parts by weight is added. (3) The air purifying cement product according to the above (1) or (2), wherein the kneaded material has a waterproof material. (4) An air purification cement product, wherein a waterproof material is applied to the surface of the air purification cement product according to the above item (1) or (2). (5) The cement product for air purification according to the above (3) or (4), wherein the waterproof material is a silicone compound.

The air purifying cement product of the present invention comprises 100 parts by weight of alumina cement and 5 parts by weight of titanium oxide to 50 parts by weight.
Parts by weight, aggregate 100 parts by weight to 700 parts by weight and water 20 to
An air-purifying cement product which is composed of a kneaded material containing 200 parts by weight, in particular, the use of alumina cement improves the air purification performance and maintains the air purification performance over time. Further, in the present invention, 10 to 200 parts by weight of the pozzolanic substance is added to 100 parts by weight of the alumina cement, but the addition of the pozzolanic substance maintains the performance as a binder and does not lower the air purification performance. Further, in the present invention, since the kneaded material contains a waterproof material, efflorescence is prevented, and as a result, the air purification performance is further improved and the air purification performance is maintained over time. When the kneaded product is formed into a product by molding or the like, a waterproof material may be applied to the surface. In particular, when the waterproof material is a silicone compound, retention of air purification performance over time is excellent.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited thereto.

The air purifying cement product of the present invention comprises 100 parts by weight of alumina cement and 5 parts by weight of titanium oxide to 50 parts by weight.
Alumina cement is a type of special cement produced by melting or coagulating limestone and alumina-based raw materials such as bauxite and ban shale, while the kneaded mixture contains 100 parts by weight and 100 to 700 parts by weight of aggregate. It is. This alumina cement is made of monocalcium aluminate (C
Since it is mainly composed of A), it not only does not generate calcium hydroxide by hydration reaction, but also has a very fast strength, develops a strength that can be practically used in several hours, and hardens in one day. It has excellent properties that contribute to shortening the curing period of cement products. Alumina cement has high chemical resistance to acids such as sulfates up to a low pH value (about pH 4), and does not deteriorate due to acid rain or the like, which contributes to the sustainability of air purification performance. In the present invention, a pozzolanic substance may be added to the alumina cement as described later, and preferred pozzolanic substances include blast furnace slag, fly ash, and silica fine powder. The amount of the pozzolanic substance added to the alumina cement is preferably from 10 to 200 parts by weight based on 100 parts by weight of the alumina cement.

The titanium oxide used in the present invention includes:
Titanium dioxide is particularly preferred, and it may have any crystal form of rutile and anatase, but anatase-type titanium dioxide having high activity is preferred. Further, these titanium dioxides contain titanium dioxide as a main component, and may further contain a small amount of titanium oxide. It is also preferable to use metatitanic acid. Hereinafter, these are collectively referred to as titanium oxide. More preferably, chemically bound water or / and hydrophilic OH ions or / and sulfate ions are present on the surface of the titanium oxide, and the surface area of the titanium dioxide is 100 to 300 m ² / g. If the specific surface area is smaller than 100 m ² / g, the NOx absorption performance is poor and thus the purification performance is poor. On the other hand, when the specific surface area exceeds 300 m ² / g, the dispersibility in cement is deteriorated, and as a result, the purification performance is deteriorated.

As the aggregate used in the present invention, a fine aggregate is preferable. As the fine aggregate, any sand such as natural sand and artificial sand may be used. In addition, one or more of granite, quartzite, lightweight aggregate, glass grains, or quartz sand can be selected instead of sand. The particle size of these is from 1.2 to
5 mm is preferred. However, in the present invention,
Part of the sand is replaced by an aggregate having good light transmission (hereinafter also referred to as light-transmitting aggregate) in order to allow the ultraviolet light to penetrate deep into the surface layer of the block and increase the purification and absorption efficiency. Glass beads, glass powder,
Silica sand and the like can be used, and the particle diameter of glass beads, glass powder and silica sand is desirably 1 to 6 mm. If the particle diameter of these light-transmitting aggregates is larger than this, the portion where cement is not present becomes large and the strength decreases. I do. If the particle size of the light-transmitting aggregate is smaller than this, light transmission will be poor.

A part of the sand as glass beads or glass powder,
When replacing with a light-transmitting aggregate such as silica sand, these amounts are preferably 10 to 50% by weight, more preferably 15 to 50% by weight, and even more preferably 20 to 50% by weight of the total aggregate amount. If the amount of the light-transmitting aggregate is less than 10% by weight, the effect of light transmission does not appear.

The present invention is characterized in that the kneaded material has a waterproof material. In the claims of the present application, "the kneaded material has a waterproof material" means that the kneaded material has a waterproof material. This includes the case where a waterproofing material is added and mixed in a kneaded material which is a raw material for producing an alumina cement product, and the case where the surface of the air purifying cement product is present by coating or impregnation. The waterproofing material used in the present invention is not particularly limited as long as it does not adversely affect the air purification performance. Specifically, an oil-based, natural resin-based or synthetic resin-based waterproofing material or the like is used. No. Examples of the synthetic resin-based waterproofing material include acrylic, ester-based, urethane-based, epoxy-based, silicone-based, and mixed waterproofing materials thereof, and any of water-based and solvent-based materials is preferable, and silicone is more preferable. It is a system waterproof material. Examples of the silicone waterproofing material include silane-based, siloxane oligomer-based, modified alkoxysiloxane-based, polysiloxane-based, and siliconate-based waterproofing materials.

[0015] Examples of the siliconate-based waterproofing material preferably used in the present invention include Polenc (PoLenC, Shin-Etsu Chemical Co., Ltd.) and TSW870 (Toshiba Silicone Co., Ltd.). Silane (monomer, oligomer) waterproofing materials include Enasel (Earth Trading), Aqua Seal 20
0S (Sumitomo Seika), Toss Barrier 100, Toss Barrier 2
00 (Toshiba Silicone Co., Ltd.). Silicone resin-based waterproof materials include TSW810 (Toshiba Silicone), Polon A (Shin-Etsu Chemical), Dry Seal L
(Toray Dow Corning Silicone), Aqua Seal 30E (Sumitomo Seika) and the like. Other acrylic resin-based waterproofing materials include Conseal CM-R (Fujikura Kasei Co., Ltd.), and other organic resin-based waterproofing materials include PolonMF-40 (Shin-Etsu Chemical Co., Ltd.) and Water Seal # 101 (Japan). Special Coatings Co., Ltd.), and Pydrotherm (Nippon Chemics Co., Ltd.).

The amount of the waterproofing material to be added to the kneaded product of the cement product for air purification of the waterproofing material used in the present invention is as follows:
0.1 part by weight to 5.0 parts by weight based on 100 parts by weight of the kneaded material.
Parts by weight, preferably 0.5 to 2 parts by weight. When the added amount of the waterproof material is less than 0.1 part by weight, it does not contribute to the improvement of the air purification performance as well as the waterproof effect. On the other hand, if the amount of the waterproofing material exceeds 5.0 parts by weight, the hydration reaction of the alumina cement is inhibited, and sufficient hardening cannot be obtained. In addition, when applied to the surface of the product, a thick waterproof film is formed on the surface, and the contact between harmful substances in the atmosphere and titanium oxide is cut off, so that good air purification performance cannot be obtained.

In the present invention, when producing an air-purifying cement product, an admixture can be added to the kneaded material. As the admixture, a pozzolanic substance is usually used, for example, blast furnace slag, fly ash, etc. , Silica fine powder, natural pozzolan, silica shume and the like, the amount of addition of alumina cement does not lose the performance as a binder, that is, 10 to 200 parts by weight of the pozzolanic substance with respect to 100 weight of alumina cement, With the addition amount in this range, 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 is preferably a building material tile, block, cement board, pavement tile, block, pavement concrete, river or seawall block, wavebreak block, or the like.

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

[0019]

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

Example 1 100 parts by weight of alumina cement (Asahi Fonju (trade name), manufactured by Asahi Glass Co., Ltd.), titanium oxide (for photocatalyst, anatase type, specific surface area 170 m ²⁾
/ G) 20 parts by weight, 320 parts by weight of aggregate (fine aggregate, mountain sand, coarse sand ratio: 1.90), and 30 parts by weight of water were mixed to prepare a kneaded product having a mortar composition. Then, a mortar molded body having a size of 10 × 10 × 0.5 (thickness) cm was produced by a one-layer pressure molding method using the kneaded material having the mortar composition. The molding pressure was 100 kg / cm ² . After curing in wet air for two weeks and drying at 60 ° C. for 24 hours, NOx purification performance was measured by a NOx purification performance measuring device. After the measurement, the specimen was exposed outdoors and the exposure time was 1 month, 3 months,
The NOx purification performances after 6 months and 1 year were measured. Table 1 shows the obtained results.

Example 2 A waterproof material (silicone water repellent; BY1) was added to the mortar composition kneaded material produced in Example 1.
6-601, manufactured by Toray Dow Corning Co., Ltd.)
After adding 1.0 part by weight to 0 part by weight and mixing,
A test body was prepared in the same manner as in Example 1, and the NOx purification performance was measured in the same manner. Table 1 shows the obtained results.

Example 3 A test piece was prepared in the same manner as in Example 1, except that the kneaded product having the mortar composition manufactured in the same manner as in Example 1 was used. The surface of the test piece was coated with the waterproof material used in Example 2, and the NOx purification performance was measured in the same manner. Table 1 shows the obtained results.

[Examples 4 to 6] A half of 100 parts by weight of the alumina cement of Example 1 was blast furnace slag fine powder (produced by Mitsubishi Materials Corporation, fineness: 4500 cm ² / g), fly ash (produced by Denka Kogyo), Silica fine powder (fineness 48
(80 cm ² / g, manufactured by Fujisaka Silica Sand) to produce kneaded products of three types of mortar compositions. A test body was prepared in the same manner as in Example 1, and the NOx purification performance was measured in the same manner. Table 1 shows the obtained results.

Comparative Example 1 A specimen 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 test of the obtained test body was performed by the method used in Example 1, and the NOx purification performance was measured. Table 1 shows the obtained results.

Comparative Example 2 A specimen was prepared in the same manner as in Example 1 except that a white cement was used instead of the alumina cement of Example 1. The test of the obtained test body was performed by the method used in Example 1, and the NOx purification performance was measured. Table 1 shows the obtained results.

Comparative Example 3 A test piece was prepared in the same manner as in Example 1 except that a white cement was used in place of the alumina cement of Example 2. The test of the obtained test body was performed by the method used in Example 1, and the NOx purification performance was measured. Table 1 shows the obtained results.

Comparative Example 4 A specimen was prepared in the same manner as in Example 1 except that white cement was used instead of the alumina cement of the kneaded product of the mortar composition produced in the same manner as in Example 3. The surface of the test piece was coated with the waterproof material used in Example 2, and the NOx purification performance was measured in the same manner. Table 1 shows the obtained results.

[0028]

[Table 1]

[0029]

The air purifying cement product of the present invention comprises 100 parts by weight of alumina cement and 5 parts by weight of titanium oxide to 5 parts by weight.
An air-purifying cement made of a kneaded mixture containing 0 parts by weight and 100 to 700 parts by weight of aggregate, and particularly, an air-purifying performance is improved by using alumina cement, and the air-purifying performance is maintained over time. The product is obtained. In addition, since the kneaded material used in the present invention contains a waterproof material, the air purification performance is further improved, and the retention of the air purification performance over time is excellent. In particular, when the waterproof material is a silicone compound, retention of air purification performance over time is excellent.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 24/42 C04B 41/49 41/49 E04B 1/92 E04B 1/92 B01D 53/36 J // (C04B 28/06 18 : 14 18:08 14:06 24:42) 103: 00 111: 21 111: 23 (72) Inventor Yutaka Yamada 1-297 Kitabukurocho, Omiya-shi, Saitama Pref. Mitsubishi Materials Corporation Cement Research Institute

Claims (5)

[Claims] 1. An air purification system comprising a kneaded mixture containing 100 parts by weight of alumina cement, 5 to 50 parts by weight of titanium oxide, 100 to 700 parts by weight of aggregate, and 20 to 200 parts by weight of water. For cement products. 2. The air purification cement product according to claim 1, wherein 10 to 200 parts by weight of a pozzolanic substance is added to 100 parts by weight of the alumina cement. 3. The air purifying cement product according to claim 1, wherein the kneaded material has a waterproof material. 4. An air purification cement product according to claim 1, wherein a waterproof material is applied to the surface of the air purification cement product according to claim 1. 5. The air purification cement product according to claim 3, wherein the waterproof material is a silicone compound.