JP3424028B2 - Photocatalyst carrying composition and method of applying the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cement-based composition containing a photocatalytic material such as titanium oxide and a method for applying the same. More specifically, when a photocatalyst material is carried on the surface of a substrate such as a cement slate board, a field board, a wall surface of concrete or mortar, a brick wall, or a tile wall, a photocatalyst-carrying composition suitable for thickly carrying it and its construction. Regarding the method.

[0002]

_2. Description of the Related Art Titanium dioxide (TiO ₂ ) has been used as a white pigment for a long time, but recently, it has been found to have an excellent photocatalytic activity, and it has been used as a photocatalyst material utilizing this characteristic in various industrial materials. There is. When manufacturing an article utilizing the photocatalytic activity function of this titanium dioxide, as a method of supporting titanium dioxide on the article (hereinafter referred to as a substrate), a method of directly mixing titanium dioxide from the raw material stage and a method of preliminarily manufacturing titanium dioxide There is a method of fixing it on the surface of the substrate. Usually, the former manufacturing method is often applied to a relatively small and highly movable substrate, and the latter manufacturing method is often applied to a relatively large and stationary substrate represented by a construct.

As a means for fixing titanium dioxide to the surface of a prefabricated substrate, the following method has been mainly used. (A) Titanium oxide on the base is sintered at high temperature to be bonded to the base. (B) Using an organic adhesive as a fixing medium, titanium dioxide is adhered onto the substrate and fixed by curing the medium components. (C) An inorganic hydraulic substance such as cement is used as a supporting medium and fixed by hardening the hydraulic component. However, the method (a) requires an apparatus for high temperature treatment, is costly, and tends to restrict the working environment. The method (b) has low physical and chemical durability. The method (c) does not cause the problems described in (a) and (b), but has a problem that the workability is deteriorated when the amount of supported titanium dioxide is increased.

That is, when an inorganic hydraulic material such as cement is used as a supporting medium as in the above method (c), a general tendency is to add water to a kneaded product of cement and titanium dioxide and knead the mixture. Then, due to the influence of titanium dioxide, the condensation proceeds in a few minutes after water injection, the fluidity becomes poor, and the work on the target substrate becomes extremely difficult. Here, with simple measures such as excessively increasing the amount of water to increase fluidity or adding a dispersant, the durability of the cement itself decreases, and depending on the organic compound added, titanium dioxide may have Photocatalytic activity such as oxidation may be significantly reduced or modified.

In order to improve this, an inorganic compound having a accelerating or strength-enhancing effect is added and the kneading operation is physically improved to maintain a relatively high fluidity from kneading to construction, and A cement-based carrier composition capable of sufficiently maintaining the original properties of titanium dioxide after construction has been proposed. However, such a cement-based carrier composition having high fluidity is most suitable for thin coating on the surface of the substrate by a spraying method or the like. For example, it can be thickened by using a trowel coating or a roller. When the construction is performed, if the base body has a large inclination during the construction and for a while after the construction, the construction is likely to fall or fall off, and it is difficult to obtain a strong fixed state. Further, after the construction, cracking and peeling were likely to occur with the progress of hardening.

[0006]

DISCLOSURE OF THE INVENTION The present invention has solved the above problems in conventional photocatalyst-carrying compositions,
The present invention provides a photocatalyst-carrying composition suitable for thick coating on a target substrate, excellent in adhesiveness, hardly dripping or falling off during construction, and hardly cracking or peeling after construction, and a construction method thereof. .

[0007]

The present inventors have found that when a cement composition containing cement as a main component and a specific amount of an aggregate, a water-thickening agent and an adhesion enhancer is mixed with an appropriate amount of water. , Does not show a significant decrease in fluidity even when a photocatalytic material such as titanium dioxide powder is added, firmly adheres to the surface of the substrate at any angle, and thick coating is possible, and excellent durability after curing is obtained. The present invention has been completed and the present invention has been completed.

That is, the present invention provides (1) cement 100
Aggregate 10 to 500 parts by weight, thickening water retention agent 0.05 to 2 parts by weight, adhesion enhancer 1 to 200 parts by weight, calcium carbonate 1 to 43 parts by weight and / or calcium hydroxide 1 to parts by weight. 43 parts by weight, and photocatalytic material 10-200
The photocatalytic material contains copper, silver, gold, lanthanum, cerium, zinc, on the surface of the particle and / or inside the particle.
Specific surface area (BET value) 20 to 35 in the presence of at least one kind of metal or metal compound of vanadium, iron, cobalt, nickel, ruthenium, rhodium, palladium, platinum
0m ² / g of anatase titanium dioxide powder, 120
The present invention relates to a photocatalyst-supporting composition, which is applied with a mortar flow value of mm or more.

The photocatalyst-supporting composition of the present invention comprises (2)
In (1), a photocatalyst-carrying composition using 0.05 to 200 parts by weight of a water-soluble polymer compound which serves as both a thickening and water-retaining agent and an adhesion enhancer, and (3) at the time of construction, with respect to 100 parts by weight of cement Then, 20 to 300 parts by weight of water is added, and the photocatalyst-supporting composition is applied at a mortar flow value of 120 mm to 170 mm.

Furthermore, the present invention provides (4) cement 100
Aggregate 10 to 500 parts by weight, thickening water retention agent 0.05 to 2 parts by weight, adhesion enhancer 1 to 200 parts by weight, calcium carbonate 1 to 43 parts by weight and / or calcium hydroxide 1 to parts by weight. 43 parts by weight, and at least one kind of metal or metal compound of copper, silver, gold, lanthanum, cerium, zinc, vanadium, iron, cobalt, nickel, ruthenium, rhodium, palladium, platinum is present on the surface and / or inside the particles. Specific surface area (BET value) 20-350
A photocatalyst-carrying composition containing 10 to 200 parts by weight of a photocatalyst material composed of anatase-type titanium dioxide powder of m ² / g and 20 to 300 parts by weight of water was first kneaded, and the kneaded product was allowed to stand and then secondly kneaded. The present invention relates to a method of applying a photocatalyst-carrying composition, which is applied with a mortar flow value of 120 mm or more.

The above-mentioned construction method of the present invention comprises: (5) a construction method using 0.05 to 200 parts by weight of a water-soluble polymer compound which serves as both a thickening and water-retaining agent and an adhesion enhancer.
(6) At the time of the secondary kneading, 0.5 parts by weight or less of water and / or a dispersant is used in an amount of 0.5 to 100 parts by weight of cement.
Add 5 parts by weight and knead, mortar flow value 120 mm
Includes construction method to adjust to ~ 170mm.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to Examples. (I) Components of Composition The photocatalyst-carrying composition of the present invention comprises cement and aggregate as basic components, and a water-soluble polymer compound which is a thickening water-retaining agent, an adhesion enhancer or both of them, Accordingly, a predetermined amount of the photocatalytic material is mixed with a mixture of calcium carbonate or calcium hydroxide. If necessary, a small amount of antifoaming agent, water reducing agent, high-performance water reducing agent, color pigment and the like can be added to the photocatalyst-carrying composition.

The photocatalyst-carrying composition of the present invention specifically comprises, for example, the following components. (A) Cement, aggregate, thickening water retention agent, adhesion enhancer and photocatalytic material. (B) A cement, an aggregate, a water-soluble polymer compound that also functions as a thickening and water-retaining agent and an adhesion enhancer, and a photocatalytic material. (C) A product obtained by adding calcium carbonate and / or calcium hydroxide to the above (A). (D) Calcium carbonate and / or calcium hydroxide added to the above (b). (E) Water added to the above (a) to (d) at the time of construction. The amount of each of these components used is 10 to 200 parts by weight of photocatalyst material and 10 to 500 parts of aggregate with respect to 100 parts by weight of cement.
Parts by weight, thickening and water-retaining agent 0.05 to 2 parts by weight, adhesion enhancer 1
To 200 parts by weight, water-soluble polymer compound 0.05 to 200
Part by weight, calcium carbonate 1-43 parts by weight and / or calcium hydroxide 1-43 parts by weight, water 20-300 parts by weight are suitable.

The type of cement used in the present invention is not limited. Various general-purpose cements such as ordinary Portland cement can be used. In terms of construction, ordinary Portland cement is preferable, and white cement is particularly preferable.

Examples of the photocatalyst material include oxide powders that promote photooxidation / reduction reaction by ultraviolet rays, and specific examples thereof include titanium dioxide, tin dioxide, zinc oxide, tungsten trioxide, cerium oxide, barium titanate and oxides. There is ferric iron. In particular, titanium dioxide has excellent photocatalytic activity, and among them, anatase titanium dioxide has high photocatalytic activity. This titanium dioxide has a specific surface area (BET value)
Is preferably ²⁰ to 350 m ² / g. Further, on the surface and / or inside of the particles of this titanium dioxide, copper,
Silver, gold, lanthanum, cerium, zinc, vanadium, iron,
The presence of at least one metal or metal compound such as cobalt, nickel, ruthenium, rhodium, palladium, or platinum can further promote the photoredox reaction.

The photocatalyst material is compounded in an amount of 10 to 200.
Parts by weight are suitable. If this amount is less than 10 parts by weight, the photocatalytic effect is poor. On the other hand, if the amount exceeds 200 parts by weight, the setting of cement will proceed rapidly and the fluidity will decrease, which may make the construction difficult, which is not preferable.

As the aggregate, an ordinary fine aggregate such as river sand or silica sand used in general mortar can be used. Of these, Class A and B stipulated in the Japan Institute of Architecture Standards (JASS)
And C type are preferable. An appropriate amount of aggregate is 10 to 500 parts by weight with respect to 100 parts by weight of cement. If the amount of aggregate is less than 10 parts by weight, the material strength becomes insufficient, which is not preferable. Further, when the amount of the aggregate exceeds 500 parts by weight, the amount of cement is relatively insufficient, so that the curing becomes poor and the material strength is lowered, and further, the aggregate is raised on the surface to cause poor coating and surface finish, which is preferable. Absent.

The thickening and water-retaining agent is an additive for imparting thickening or water-retaining property, and examples thereof include methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose,
Cellulosic compounds such as methyl hydroxyethyl cellulose and hydroxypropyl methyl cellulose, acrylic compounds such as acrylamide, and vinyl compounds such as polyvinyl alcohol can be used. An appropriate amount of the thickening and water-retaining agent added is 0.05 to 2 parts by weight. If the amount of the thickening and water-retaining agent is less than this, the water retention becomes insufficient, and cracking tends to occur after curing. On the other hand, if the amount of the thickening and water-retaining agent is more than this range, the fluidity is lowered and it becomes difficult to handle.

The adhesion enhancer is an additive that prevents cracking and peeling after curing and enhances the adhesive strength. For example, polymer emulsions of ethylene vinyl acetate type, acrylic type, styrene butadiene rubber type, etc. can be used. The amount of the adhesion enhancer added is appropriately 1 to 200 parts by weight. If the addition amount is less than 1 part by weight, cracking and peeling easily occur after curing, and the adhesive strength is not improved. If the addition amount exceeds 200 parts by weight, the viscosity becomes high, so that the fluidity is lowered, and also the liquid drips easily solidify and the workability is deteriorated.

The above-mentioned thickening and water-retaining agent and the adhesion enhancer are used in combination, but a water-soluble polymer compound which also has these properties may be substituted. For example, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and the like listed as the thickening and water-retaining agent also have a property as an adhesion enhancer. Further, a part of the acrylic polymer and the styrene-butadiene polymer emulsion shown as the adhesion enhancer also have properties as a thickening and water-retaining agent. In addition to this, examples of the water-soluble polymer compound that also serves as a thickener and water retention agent and an adhesion enhancer include, for example, the following cellulose-based thickeners, acrylic acid-based thickeners, vegetable thickeners, emulsion / latex-based thickeners. Compounds can be used.

(A) Cellulosic thickeners: carboxylated methyl cellulose, cellulose xanthate. (B) Acrylic acid thickener: ammonium polyacrylate, sodium polyacrylate, ammonium polymethacrylate, acrylic acid polymer, acrylic emulsion copolymer, polyvinyl alcohol, vinylpyrrolidone copolymer, polyacrylamide, polyvinyl acetate emulsion, acetic acid Vinyl-ethylene copolymer emulsion, polyethylene oxide. (C) Vegetable thickener: Alginate thickener, gum arabic, gum karaya, gum guar, locust bean gum, pectate. (D) Emulsion / latex: natural gum, styrene-butadiene polymer, acrylonitrile-butadiene polymer, polychloroprene, butyl rubber, polyurethane,
Polybutene, polyacrylate, polyethylene.

The amount of the above water-soluble polymer compound used is 0.0
5 to 200 parts by weight is suitable. If it is less than this amount, water retention and adhesive strength will be insufficient, while if it exceeds this amount, the viscosity will be excessive and the workability will be reduced.

The photocatalyst-supporting composition of the present invention can contain calcium carbonate or calcium hydroxide.
Thereby, the fluidity can be maintained high for a long time and the workability can be enhanced. That is, since calcium ions of calcium carbonate or calcium hydroxide are taken into the aluminate phase in the cement together with water, it is possible to avoid the situation in which the entire amount of water used is immediately spent on the hydration reaction of the cement. The rapid hydration of the aluminate phase is suppressed, and the fluidity is maintained for a relatively long time due to the presence of unreacted water gradually supplied to the reaction. Therefore, even if the amount of the functional powder added to the cement composition is increased, the fluidity can be maintained high for a long time without increasing the amount of water. It should be noted that calcium oxide (quick lime) is not suitable because such an effect is small and other effects occur.

Calcium carbonate or calcium hydroxide may be used alone or in combination. The amount used is 1 to 43 parts by weight per 100 parts by weight of cement, whether used alone or mixed. If the amount used is less than 1 part by weight, there is almost no effect of increasing the fluidity, and even if the amount used exceeds 43 parts by weight, the fluidity reaches the ceiling.

Further, the photocatalyst-carrying composition of the present invention, when applied, is based on 100 parts by weight of cement.
20-300 parts by weight of water are added. If the amount of water injected is less than 20 parts by weight, the amount of water will be insufficient with respect to the amount of cement and the resin will not cure. If the amount of water injected exceeds 300 parts by weight, the fluidity will be excessive, resulting in poor construction.

The photocatalyst-supporting composition of the present invention may contain a small amount of antifoaming agent, if necessary. As this, a known material can be used, and an appropriate amount is 0.5 to 1 part by weight. Further, various color pigments can be added in appropriate amounts. By adding a coloring pigment, it is possible to maintain the integrity with the underlying (target substrate) and the surrounding color tone, or to adjust to an appropriate color tone.

(II) Construction method When the photocatalyst-supporting composition of the present invention is constructed, water is added to the photocatalyst-supporting composition so that the amount of water is 20 to 300 parts by weight relative to 100 parts by weight of cement, Alternatively, the photocatalyst-carrying composition is added to water and primary kneading is performed. After the kneaded product is allowed to stand, secondary kneading is performed to obtain a mortar flow value of 120 mm
It is preferable to use the one described above. At the time of the secondary kneading, mortar flow value is 120 mm or more by adding 50 parts by weight or less of water and / or 0.5 to 5 parts by weight of a dispersant to 100 parts by weight of cement and kneading the mixture back. It is good to arrange. The mortar flow value is a value measured by the method specified in Japanese Industrial Standard JIS R 5201.

When the amount of the photocatalyst material mixed with the cement is large, the fluidity of the composition is lowered, and the coating and spraying work becomes difficult. Generally, a kneaded product having a mortar flow value of less than 120 mm is not suitable for such work. Mortar flow value 1
A kneaded material having a mortar flow value of 120 mm or more is obtained by kneading the kneaded material (primary kneaded material) again for a kneaded material of less than 20 mm.
It is constructed as (secondary kneaded material). During this secondary kneading,
It is advisable to add a small amount of water to 100 parts by weight of cement and knead it back. The upper limit of the amount of the secondary kneading water added is 50 parts by weight, preferably 30 parts by weight or less, and more preferably 20 parts by weight or less. If the amount of water exceeds 50 parts by weight, the amount of water will be excessive and the durability of the cement itself will be reduced, leading to a decrease in strength of the composition. In this secondary kneading, it is better to re-add the water after the primary kneaded product is kneaded and then knead, rather than re-adding water immediately after the primary kneading and kneading.
By kneading the primary kneaded product and adding water again, the familiarity between the kneaded product and water is improved, and the fluidity can be increased with a smaller amount of water. Further, instead of water, or together with water, 0.5 to 5 parts by weight of one or more dispersants such as a water reducing agent, a high-performance water reducing agent, and a high-performance AE water reducing agent may be added and kneaded. good.

An example of construction of the photocatalyst-supporting composition of the present invention is shown below. Note that the following construction procedure is an example, and the construction method is not limited to this example. (B) Substrate adjustment: After removing dirt, dust, and oils on the construction surface, and then washing, remove latances and large protrusions, and fill cement-based surface adjustment material in extreme steps and recesses. Flatten the surface and lightly polish the surface to improve adhesion. (B) Primer application: A primer may be applied to improve the bondability of the photocatalyst-supporting composition to the underlying surface. It is advisable to apply twice to enhance the application effect. The coated surface is dried to prepare for application of the photocatalyst supporting composition.

(C) Preparation of photocatalyst-carrying composition: The above-mentioned photocatalyst-carrying composition of the present invention is poured into water and kneaded to prepare a paste form. At this time, put the adhesion enhancer in water first to disperse,
It is advisable to gradually add cement, aggregate, and photocatalytic material such as titanium dioxide powder to this and knead (primary kneading). The kneading time may be about 2 to 3 minutes. Preferably, after the above primary kneading, the mixture is allowed to stand for 2 to 3 minutes and further secondary kneading is performed. That is, after leaving the primary kneading still for about 30 seconds,
After kneading, a water reducing agent is added and kneading is performed for about 1 to 2 minutes (secondary kneading). During this secondary kneading, the mortar flow value is 120 mm or more, preferably 1 by adjusting the amount of the water reducing agent.
Adjust so that it is 20 to 170 mm. (D) Application / Coating: The prepared paste-like photocatalyst-carrying composition is contained in a roller or the like, and the excess is scraped off and applied to the construction surface. It should be noted that the surface may be smoothed after coating so that the coated surface becomes uniform.

[0031]

EXAMPLES AND COMPARATIVE EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. Examples and Comparative Examples To the amount of water shown in Table 1, white cement (manufactured by Chichibu Onoda Co., Ltd.),
Aggregate (silica sand), thickening water retention agent (methyl cellulose), adhesion enhancer (acrylic polymer A), or water-soluble polymer compound (acrylic polymer B) also serving as a thickening water retention agent and adhesion enhancer, calcium carbonate, Table 1 shows calcium hydroxide and a photocatalyst material (titanium dioxide powder having 8% by weight of lanthanum hydroxide supported on the particle surface, specific surface area of 250 m ² / g, average particle size of 7 nm).
The mixture is gradually added so as to have the compounding amount shown in (1), and the mixture is first kneaded for 2 to 3 minutes and then allowed to stand, and then kneaded again to add a high performance AE water reducing agent (polycarboxylic acid salt), and further 1 to 2 minutes Next, kneading was performed to adjust the mortar flow value to 120 to 170 mm. This was applied to a surface of a cement slate plate installed vertically to the ground surface by using a roller to a thickness of about 2 mm. The condition of the coated surface of each sample is summarized in Table 1. As is clear from these results, the photocatalyst-carrying composition of the present invention has no sagging or falling off of the coated surface, does not cause cracking or peeling after drying and curing, and exhibits a good coating effect. On the other hand, those that deviate from the component amount ratio of the present invention cause cracking after curing,
In some cases, the coated surface is dripping or falling off.

[0032]

[Table 1]

[0033]

INDUSTRIAL APPLICABILITY The photocatalyst-supporting composition of the present invention is suitable for supporting and thickly coating a photocatalyst material, and is applicable to cement slate boards, field boards, concrete or mortar wall surfaces, brick walls, tile walls, and other target substrates. It has excellent adhesiveness to the material, and even if it is applied thickly, there is almost no sagging or falling off of the coated surface, and there is almost no cracking or peeling after application.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C04B 14:02 C04B 24:38 Z 24:38 24:26 D 24:26 22:06 Z 22:06) 103: 46 103: 46 103: 69 103: 69 111: 20 111: 20 (72) Inventor Katsuko Kaneko 2-4-2 Daisaku Sakura, Chiba Prefecture Chichibu Onoda Co., Ltd. Central Research Laboratory (72) Inventor Yuhisa Kaneda Sakura City, Chiba Prefecture 2-4-2 Daisaku Chichibu Onoda Central Research Institute (72) Inventor Koichi Soeda Sakura City, Chiba Prefecture 2-4-2 Chichibu Onoda Central Research Institute (72) Inventor Hiroshi Yamaguchi Yokkaichi, Mie Prefecture 1 Ishihara-cho Ishihara Sangyo Co., Ltd. Yokkaichi Plant (72) Inventor Keiji Ibusuki 16-3 Onogawa, Tsukuba, Ibaraki Prefectural Institute of Industrial Science and Technology (72) Inventor Hiroshi Takeuchi Ono, Tsukuba, Ibaraki No. 16-3, Institute of Resources and Environmental Technology, Industrial Technology Institute (56) References JP-A-9-296532 (JP, A) JP-A-11-147748 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C04B 28/02-28/12 C04B 41/61

Claims (6)

(57) [Claims] 1. An aggregate of 10 parts by weight relative to 100 parts by weight of cement.
.About.500 parts by weight, thickening and water-retaining agent 0.05 to 2 parts by weight, adhesion enhancer 1 to 200 parts by weight, calcium carbonate 1 to 43 parts by weight and / or calcium hydroxide 1 to 43 parts by weight, and photocatalytic material 10 The photocatalytic material contains 200 parts by weight of copper, silver, gold, on the surface and / or inside the particles,
At least one kind of metal or metal compound of lanthanum, cerium, zinc, vanadium, iron, cobalt, nickel, ruthenium, rhodium, palladium, platinum is present,
A photocatalyst-supporting composition, which is an anatase-type titanium dioxide powder having a specific surface area (BET value) of 20 to 350 m ² / g, and which is applied with a mortar flow value of 120 mm or more. 2. The water-soluble polymer compound as defined in claim 1, which is a water-soluble polymer compound having both functions of a thickener and water retention agent and an adhesion enhancer.
A photocatalyst-supporting composition using 5 to 200 parts by weight. 3. At the time of construction, 20 to 300 parts by weight of water is added to 100 parts by weight of cement, and 120 mm to 17 mm
A mortar flow value of 0 mm is applied for construction.
The photocatalyst-supporting composition according to any one of 1. 4. Aggregate 10 with respect to 100 parts by weight of cement.
To 500 parts by weight, a thickening and water-retaining agent 0.05 to 2 parts by weight, an adhesion enhancer 1 to 200 parts by weight, calcium carbonate 1 to 43 parts by weight and / or calcium hydroxide 1 to 43 parts by weight, and particle surface and / or Or copper, silver, gold, lanthanum, cerium, zinc, vanadium, iron, cobalt inside the particles,
Nickel, ruthenium, rhodium, palladium, platinum
Photocatalyst support containing 10 to 200 parts by weight of anatase type titanium dioxide powder having a specific surface area (BET value) of 20 to 350 m ² / g and containing 20 to 300 parts by weight of water in the presence of at least one kind of metal or metal compound A method for applying a photocatalyst-carrying composition, which comprises firstly kneading the composition, allowing the kneaded product to stand, and then secondarily kneading the composition so that the mortar flow value is 120 mm or more. 5. The construction method according to claim 4, wherein 0.05 to 200 parts by weight of a water-soluble polymer compound which serves as both the thickening and water-retaining agent and the adhesion enhancer is used instead of the thickening and water-retaining agent. 6. In the secondary kneading, 0.5 to 5 parts by weight of water and / or a dispersant are added in an amount of 50 parts by weight or less with respect to 100 parts by weight of cement, and the mixture is kneaded. The construction method according to claim 4, wherein the construction is adjusted to 170 mm.