JP2000034145A - Concrete product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decompose NOx or SOx in the atmosphere, contribute to the atmospheric cleaning and prevent even the fouling of a concrete product itself by embedding titanium dioxide-coated granular materials forming a titanium dioxide film on the surface of granular decorative materials in the surface of a concrete substrate so as to expose a part of the surface. SOLUTION: A titanium dioxide film 35 is formed on each surface 22 in all or a part of granular decorative materials 21 embedded in a concrete substrate 11 to provide many titanium dioxide-coated granular materials 31, which are embedded in the surface 12 of the concrete substrate 11 in the same manner as that of the granular decorative materials 21 uncoated with the titanium dioxide film 35. When the granular decorative materials 21 are made of glass beads, rainbow-colored reflected light is obtained in exposing the titanium dioxide-coated granular materials 31 to light to provide a concrete product excellent in decorativeness. The granular decorative materials 21 have 0.1-10 mm grain diameter and are composed of glass beads, pebbles, ceramic chips, etc. The surfaces thereof are coated with a titanium dioxide sol, then dried, baked and crystallized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a concrete product.

[0002]

2. Description of the Related Art Concrete products such as concrete blocks provided on the edge of sidewalks, concrete road surface materials for sidewalks and roadways, concrete blocks for building outer walls, concrete blocks for waterway construction, gutters, gutter lids and vegetation blocks. Is to expose a part of the surface of a granular decorative material such as glass beads, glass cullet, pebbles, ceramic chips, etc., for the purpose of imparting decorative properties or imparting reflection characteristics upon receiving light. Buried in the concrete surface in this way.

In recent years, air pollution by harmful chemical substances such as NOx and SOx, which are artificially emitted, such as smoke from factories and exhaust gas from vehicles, has become a serious problem. Also, recently, when titanium dioxide is irradiated with light, the photocatalytic action of titanium dioxide, which generates electrons having a strong reducing action and holes having a strong oxidizing action, is known as NOx or SO2.
It has been found that it is effective for decomposing harmful chemical substances such as x and odorous substances, or for sterilization and fungicide.

The inventors of the present invention have studied whether the photocatalytic action of titanium dioxide can be applied to the above-mentioned concrete products, and as a result, have accomplished the present invention.

[0005]

That is, the present invention provides:
NOx in the atmosphere utilizing the photocatalytic action of titanium dioxide
An object of the present invention is to provide a concrete product that can decompose air pollutants such as CO2 and SOx, contribute to air purification, and prevent the concrete product itself from being stained.

[0006]

According to the first aspect of the present invention, a titanium dioxide-coated granular material having a titanium dioxide film formed on the surface of a granular decorative material is embedded in the surface of a concrete base material such that a part of the surface is exposed. The present invention relates to a concrete product characterized in that:

According to a second aspect of the present invention, there is provided a method of manufacturing a concrete base material, comprising the steps of: providing a granular decorative material and a titanium dioxide-coated granular material having a titanium dioxide film formed on the surface of the granular decorative material so that a part of the surface is exposed; And a protrusion height of the titanium dioxide-coated granular material from the surface of the concrete base material is smaller than a protrusion height of the granular decorative material from the surface of the concrete base material. .

According to a third aspect of the present invention, the granular decorative material according to the second aspect comprises two or more types of particles including glass beads, and a titanium dioxide film is formed on the surface of the granular decorative material comprising the glass beads. And

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing a concrete product according to one embodiment of the present invention, FIG. 2 is an enlarged sectional view of the concrete product, FIG. 3 is a sectional view showing an initial step in manufacturing the concrete product, and FIG. FIG. 5 is a cross-sectional view illustrating a step of embedding the titanium dioxide-coated granules, FIG. 6 is a cross-sectional view illustrating a step of placing concrete, and FIG. 7 is a cross-sectional view illustrating a step of solidifying the concrete. FIG. 8 is a sectional view showing a step of removing the sheet and the fixing agent, and FIG. 9 is a schematic view of an apparatus used in an example of the production of titanium dioxide-coated granules.

A concrete product 1 shown in FIGS. 1 and 2
Numeral 0 is used as, for example, a block provided on an edge of a sidewalk, a road surface material of a sidewalk or a road, a block for an outer wall of a building, a block for a waterway, a gutter, a lid for a gutter, a vegetation block, and the like. Base material 11 and granular decorative material 2
1 and titanium dioxide-coated granules 31.

The concrete substrate 11 is made of ordinary concrete or lightweight cellular concrete molded in a formwork in a factory, ordinary concrete by so-called on-site construction (casting), etc., and has a required shape (plate shape in the figure) according to the application. Formed. The concrete used for the concrete substrate 11 generally shows alkalinity.

The granular decorative material 21 is for imparting decorative properties, reflection characteristics when receiving light, etc. to the concrete product 10, and the granular decorative material 21 includes glass beads, glass cullet, pebbles, Ceramic chips and the like can be mentioned. The size is generally about 0.1 to 10 mm in particle size. A large number of the granular decorative materials 21 are buried in the surface 12 of the concrete base material 11 such that a part of the surface 22 is exposed.

In this concrete product 10, the whole or a part (in this embodiment, a part) of the large number of the granular decorative materials 21 embedded in the concrete base material 11 is disposed on the surface 22 of the granular decorative material 21. Titanium dioxide coating 3
5 is formed to be a titanium dioxide-coated granular material 31.
A large number of the titanium dioxide-coated particles 31 are also buried in the surface 12 of the concrete base material 11, similarly to the granular decorative material 21 not covered with the titanium dioxide film.

If the particulate decorative material 21 on which the titanium dioxide film 35 is formed is made of glass beads, a rainbow-colored reflected light can be obtained when light is applied to the titanium dioxide-coated particulate material. Thus, a concrete product 10 having extremely excellent decorativeness can be obtained. In that case, the granular decorative material 21
If two or more materials having different materials are used, excellent decorativeness can be obtained according to the use of the concrete product 10.

The titanium dioxide film 35 is formed, for example, by coating a titanium dioxide sol on the surface 22 of the particulate decorative material 21 by a known dip coating method or spin coating method, and then converting the titanium dioxide sol to a wet sol. Further, it may be carried out by crystallization by drying and baking, or as described in Japanese Patent Application No. 9-14495 previously filed by the present applicant, which comprises a supercritical material comprising carbon dioxide or alcohol. Fluids (fluids that exceed the critical temperature and pressure inherent in substances)
A mixed supercritical fluid in which a sol of titanium dioxide is mixed in, or a mixed supercritical fluid in which an organotitanium compound such as titanium alkoxide is dissolved is heated and sprayed onto the surface 22 of the particulate decorative material 21 while rapidly reducing the pressure, or
The mixed supercritical fluid is rapidly decompressed and sprayed onto the surface 22 of the particulate decorative material 21 and the surface 22
May be performed by heating. In particular, if the titanium dioxide film 35 is formed using the mixed supercritical fluid, the titanium dioxide film 35 can be easily and quickly formed without being restricted by the size and material of the particulate decorative material 21 or the conditions of the construction site. be able to. The method of forming the titanium dioxide film 35 is not limited to the above.

The sol of titanium dioxide is obtained by suspending ultrafine titanium dioxide in water or hydrolyzing an alkoxide of titanium obtained by a reaction between an alcohol and a titanium salt or titanium metal with an acid or alkali as a catalyst. (Sol-gel method). On the other hand, examples of the organic titanium compound include titanium alkoxides such as ethoxide, butoxide, isopropoxide and n-propoxide of titanium and alkoxides thereof and mixtures thereof, and acetate, oxalate and 2-ethylhexanoate of titanium. , Stearates, lactates, acetylacetates, and other organic acid salts, and mixtures thereof, including alcohols, alcoholamines, glycols, ethylene glycol, ethylene oxide, xylene, dioxane, formamide, dimethylformamide, and oxalic acid. May be added. When the titanium dioxide film 35 is formed using the mixed supercritical fluid in which the organic titanium compound is dissolved, when the mixed supercritical fluid is decompressed, the mixed supercritical fluid is contact-oxidized with high-temperature air or high-temperature oxygen, or the mixed supercritical fluid is mixed. It is preferable to promote oxidative decomposition (production of titanium dioxide) by contacting with subcritical or supercritical water before the pressure reduction.

An embodiment of the production of the titanium dioxide-coated granules 31 will be described below in detail. In this specific example,
The titanium dioxide coating apparatus E shown in FIG. 9 is used. The titanium dioxide coating apparatus E includes a carbon dioxide supply unit 60.
And a supercritical fluid generation unit 70, a mixed supercritical fluid generation unit 80, and a jetting unit 90.

The carbon dioxide supply unit 60 has a carbon dioxide cylinder 61, and supplies carbon dioxide from the cylinder 61 to the supercritical fluid generator 70 via a pipe 62. Note that alcohol such as methanol may be used instead of carbon dioxide. In this example, carbon dioxide at 31 ° C. is pressurized to 100 atm by a high-pressure pump 63 provided in the middle of the pipe 62, and then supplied to the supercritical fluid generator 70. Reference numeral 64 denotes a dryer, 65
Is a cooling device, 66 is a filter, 67 is a pressure gauge, and 68 is a safety valve.

The supercritical fluid generating section 70 is a section for heating the pressurized carbon dioxide to form a supercritical fluid. In this example, the thermostatic bath 71 also serves as the mixed supercritical fluid generating section 80.
It is provided within. The constant temperature bath 71 can be maintained at an arbitrary temperature of 40 ° C. to 250 ° C., and is maintained at 100 ° C. in this example. This supercritical fluid generator 70
Is connected to the carbon dioxide cylinder 61 by a pipe 62 via a high-pressure pump 63 and the like, and the pressurized carbon dioxide is heated to 80 ° C. by a preheater 72 to be a supercritical fluid. Reference numeral 73 denotes a stopper.

The mixed supercritical fluid generating unit 80 is a unit that mixes a supercritical fluid such as carbon dioxide generated by the supercritical fluid generating unit 70 with a sol of titanium dioxide to generate a mixed supercritical fluid. This mixed supercritical fluid generation unit 80 includes:
It has an extraction cell 81 connected to the supercritical fluid generation unit 70 by a pipe 62. The extraction cell 81 is provided with a stirring device 82 rotated by a stirring motor and a pipe 62A for supplying a sol of titanium dioxide. Then, a predetermined amount of sol of titanium dioxide is supplied to the extraction cell 81 through the pipe 62A, and is mixed with the supercritical fluid of carbon dioxide supplied from the supercritical fluid generation unit 70 to generate a mixed supercritical fluid. Is done. In this example, a supercritical fluid of titanium dioxide sol and carbon dioxide was supplied into the extraction cell 81 at a weight ratio of 1:30 to produce a mixed supercritical fluid at 100 atm and 80 ° C. The titanium dioxide sol used was one produced by a known sol-gel method. Reference numeral 61A is a titanium dioxide sol container, 63A is a high-pressure pump, 66A is a filter, 67A and 83 are pressure gauges, 68A and 85 are safety valves, and 84 is a thermometer.

The jetting portion 90 is a portion for spraying the mixed supercritical fluid to the particulate decorative material 21. An expansion nozzle 92 is attached to a tip of a hose 91 connected to the extraction cell 81. Then, the surface 2 of the granular decorative material 21 arranged on the conveyor 96 passing through the diffusion prevention box 95
2, the mixed supercritical fluid is sprayed from the expansion nozzle 92. Next, after recovering the particulate decorative material 21 onto which the mixed supercritical fluid has been sprayed from the conveyor 96, the surface 22 of the granular decorative material 21 is heated by a heating device (not shown), whereby the granular decorative material 21 is heated. A titanium dioxide film 35 was formed on the surface 22 to obtain the titanium dioxide-coated granular material 31. In this example, glass beads having a particle size of 2 to 4 mm are used as the particulate decorative material 21, and a nozzle 92 is used.
Was 0.1 to 0.3 mm, the discharge pressure of the mixed supercritical fluid was 10 to 30 MPa, and the heating device was a near-infrared heating device, and the surface 22 of the particulate decorative material 21 was heated to 400 ° C. The titanium dioxide film 35 thus formed on the surface 22 of the particulate decorative material 21 had a crystal form of anatase and a thickness of 1 to 5 μm.

The concrete product 1 constructed as described above
0, when the titanium dioxide film 35 in the portion of the titanium dioxide-coated granular material 31 exposed from the surface 12 of the concrete substrate 11 receives light such as sunlight or electric light,
Since an electron having a strong reducing action and a hole having a strong oxidizing action are generated on the titanium dioxide film 35 to perform an oxidation-reduction action, air pollutants such as NOx and SOx in the atmosphere which come into contact with the oxidation-reduction action are removed. It can be decomposed and can contribute to air purification. Further, since the concrete used for the concrete substrate 11 is alkaline, the photocatalytic action of the titanium dioxide film 35 causes N
Sulfuric acid (HNO) generated when decomposing Ox, SOx, etc.
₃ ) It is possible to neutralize acidic substances such as the above, and the natural environment protection effect is high. Further, the air pollutants such as NOx and SOx are decomposed on the surface of the concrete product 10, and furthermore, the redox effect of the titanium dioxide provides a sterilization and fungicidal effect on the surface of the concrete product 10. It is difficult for dirt to adhere to the surface of
Aesthetics can be maintained for a long time.

Further, as in this embodiment, the granular decorative material 21 not covered with the titanium dioxide film and the granular decorative material 2
When the titanium dioxide-coated granular material 31 having the titanium dioxide film 35 formed on one surface 22 is buried in the concrete substrate 11 surface 12 such that a part of the surfaces 22, 32 is exposed, the concrete substrate 11 surface 12
It is preferable that the protrusion height h of the titanium dioxide-coated granular material 31 from the surface of the concrete base material 11 is smaller than the protrusion height i of the granular decorative material 21 not covered with the titanium dioxide film. In this way, even when the concrete product 10 is used as a road surface material for a sidewalk or a road where the surface is frequently worn by traffic of a person or a vehicle, etc., the titanium dioxide-coated granular material 31 is used due to the wear. Of the titanium dioxide film 35 can be prevented. Further, among the granular decorative materials 21 that are covered with the titanium dioxide film are smaller than the granular decorative materials not covered with other titanium dioxide films, the heights h and i can be easily set. Can be.

As a means for embedding the particulate decorative material 21 and the titanium dioxide-coated particulate material 31 on the surface 12 of the concrete substrate 11, it is preferable to use a sheet transfer method. Hereinafter, an example of manufacturing the concrete product 10 using the sheet transfer method will be described.

First, as shown in FIG. 3, a highly water-permeable sheet 52 made of nonwoven fabric, polyethylene or the like is placed in a mold 51.
And a predetermined amount of the two-component fixing agent 53 is discharged to permeate the sheet 52.

The fixing agent 53 preferably has good adhesiveness to the sheet 52 and good releasability (peelability) to concrete. Particularly, a hydrophilic polyurethane resin liquid and a polyolefin-based wax, a natural wax, a silicone-based A two-part liquid prepared by mixing a water-soluble liquid in which a release agent such as wax is emulsified at a predetermined mixing ratio (for example, hydrophilic polyurethane resin liquid: a water-soluble liquid in which the release agent is emulsified = 20: 80) and stirring and mixing. A cold reaction type hydrated solid is preferred.

Next, as shown in FIG.
3, the granular decorative material 21 not covered with the titanium dioxide film is placed so that the surface to be exposed faces downward,
The granular decorative material 21 is placed at a predetermined depth m (= the granular decorative material 21).
Is embedded only by the protrusion height i). Further, as shown in FIG. 5, the titanium dioxide-coated granular material 3
1 is placed so that the surface to be exposed faces downward, and the titanium dioxide-coated granules 31 are embedded to a predetermined depth n (= projection height h of the titanium dioxide-coated granules 31). At this time, the embedding depth n of the titanium dioxide-coated granular material 31 is changed to the granular decorative material 21 not covered with the titanium dioxide film.
Is smaller than the embedding depth m, the protrusion height of the titanium dioxide-coated granular material 31 from the surface 12 of the concrete base material 11 as described above is increased. It can be smaller than the protrusion height. The embedding of the particulate decorative material 21 and the titanium dioxide-coated particulate material 31 in the fixing agent 53 may be performed simultaneously.

Next, after the fixing agent 53 is cured (gelled) by curing, and the fixing agent 53 and the sheet 52 are integrated, as shown in FIG. Decorative material 21 and titanium dioxide-coated granular material 31
Concrete C is cast into the formwork 51 so as to cover.
Note that a reinforcing bar (not shown) may be incorporated in the mold 51 while the fixing agent 53 is solidified. The sheet 5
2. A sheet is provided separately on which the adhesive 53 is provided and the particulate decorative material 21 and the titanium dioxide-coated granular material 31 are embedded, and the sheet is placed in a concrete product form and the concrete is poured. May be performed.

Then, as shown in FIG. 7, the concrete C is cured by pre-curing at room temperature, pre-curing by steam heating, and post-curing at room temperature to form a concrete base material 11, and then the mold 51 is removed. . Then, as shown in FIG.
The concrete product 10 as shown in FIG. 1 and FIG. 2 is obtained by peeling off and removing. The sheet 5
When water is supplied from the surface of the sheet 52 when peeling off the adhesive 2 and the fixing agent 53, the sheet 52 has good water permeability,
The fixing agent 53 absorbs water and swells, so that the sheet 52 and the fixing agent 53 are easily separated from the concrete substrate 11.

As in the above example, the concrete product 10
Is manufactured, the granular decorative material 21 or the titanium dioxide-coated granular material 31 embedded in the concrete substrate 11 is not completely buried in the concrete substrate 11, and Part of the surface 32 of the granular material 31 can be easily exposed from the surface 12 of the concrete substrate 11. Therefore,
Since the titanium dioxide film 35 of the titanium dioxide-coated granular material 31 is reliably exposed and can receive light such as sunlight or an electric light, the above-described photocatalytic effect of the titanium dioxide film 35 can be sufficiently exhibited. . Moreover, there is no fear of damaging the surface of the concrete product 10 during the production, and the concrete product 10 can be finished beautifully.

Here, the concrete product 1 according to the present invention
0 (the means for embedding the particulate decorative material 21 and the titanium dioxide-coated particulate material 31 in the surface 12 of the concrete substrate 11 so that a part of their surfaces 22, 32 are exposed) is limited to the above example. Instead, for example, the granular decorative material 21 and the titanium dioxide-coated granular material 31 are placed on the bottom of the mold frame with the surface to be exposed facing down, and the granular decorative material 21 and the titanium dioxide-coated granular material 31 are placed around the granular decorative material 21 and the titanium dioxide-coated granular material 31. The granular decorative material 21 and the titanium dioxide-coated granular material 31 are embedded to a predetermined depth by laying sand, cans, paraffin and the like, and then concrete is poured so as to cover the granular decorative material 21 and the titanium dioxide-coated granular material 31. After the concrete has solidified, the sand, cans, paraffin, etc. are removed by spraying with pressure water or the like, and are removed by heating and melting. By washout method may produce the concrete product 10.

The detoxifying effect of the concrete product of the present invention on NOx as an air pollutant was examined as follows. That is, a transparent container is connected in the middle of a pipe through which a gas containing NOx flows, and the concrete product according to the present invention is placed in the container, and the container is irradiated with ultraviolet light or irradiation is stopped, and after passing through the container. The amount of NOx contained in the gas was measured. As a result, NOx was immediately decomposed and reduced by ultraviolet irradiation, and when the ultraviolet irradiation was stopped, NOx increased again. In addition, when the block-shaped concrete product according to the present invention and the ordinary concrete block were left outdoors for one month and observed for dirt on the surface, the product of the present invention was clearly low in dirt.

[0033]

As shown and described above, according to the concrete product of the present invention, the photocatalytic action of the titanium dioxide coating on the titanium dioxide-coated granules embedded in the concrete substrate so that a part of the surface is exposed. In addition, air pollutants such as NOx and SOx in the atmosphere can be decomposed, which can contribute to air purification. Moreover,
Since the concrete substrate is alkaline, the photocatalytic action of the titanium dioxide film by the alkali causes NO.
Acidic substances such as sulfuric acid generated when x and SOx are decomposed can be neutralized, and the natural environment protection effect is high. Also, there is an effect that the surface of the concrete product is hardly stained.

Further, the protrusion height of the titanium dioxide-coated granules on which the titanium dioxide film is formed from the surface of the concrete substrate is covered with the titanium dioxide film from the surface of the concrete substrate. By making the height smaller than the protrusion height of the undecided granular decorative material, even when the concrete product is used for an application in which the surface is frequently worn, it is possible to prevent the titanium dioxide film from being abraded by the wear. it can.

Further, when the particulate decorative material covered with the titanium dioxide film is made of glass beads as in the third aspect of the present invention, rainbow-colored reflected light is generated when light is applied, and the decorative property is extremely excellent. It will be.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a concrete product according to one embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the concrete product.

FIG. 3 is a cross-sectional view showing an initial step in manufacturing the concrete product.

FIG. 4 is a cross-sectional view showing a step of embedding a granular decorative material.

FIG. 5 is a cross-sectional view showing a step of embedding the titanium dioxide-coated granular material.

FIG. 6 is a cross-sectional view showing a concrete placing step.

FIG. 7 is a sectional view showing a concrete solidification step.

FIG. 8 is a cross-sectional view showing a step of removing a sheet and a fixing agent.

FIG. 9 is a schematic view of an apparatus used for an example of production of titanium dioxide-coated granules.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Concrete product 11 Concrete base material 12 Concrete base material surface 21 Granular decorative material 22 Granular decorative material surface 31 Titanium dioxide coated granular material 32 Titanium dioxide coated granular material surface 35 Titanium dioxide film h Projection height of titanium dioxide coated granular material Sa i Projection height of granular decorative material

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) E04C 2/04 E04F 13/14 102A E04F 13/14 102 B01D 53/36 J (72) Inventor Toshio Watanabe Aichi 1 Sakaguchi, Kazuno, Nada-cho, Nada-gun, Fukushima Prefecture 1 F-term in Tokai Precon Corporation (reference) 2E110 AA28 AA65 AB04 AB22 AB46 BA02 BA12 BB09 GA33X GA43W GB13W GB23X GB26W GB32W 2E162 CA11 EA03 4D048 AA02 AA10 AB07 CC70 EA01 4G052 AB27 4G069 AA03 AA08 BA00 BA04A BA04B BA14A BA14B BA48A CA01 CA10 CA11 CA12 CA13 EA08 EB15Y EB18Y EC22Y ED04 FA03 FB04 FB23 FB24 FB66 FB79

Claims (3)

[Claims] 1. A concrete product wherein a titanium dioxide-coated granular material having a titanium dioxide film formed on the surface of a granular decorative material is embedded in the surface of a concrete base material such that a part of the surface is exposed. 2. A method for embedding a granular decorative material and a titanium dioxide-coated granular material having a titanium dioxide film formed on a surface of the granular decorative material on a surface of a concrete base material such that a part of the surface is exposed, A concrete product wherein the height of the titanium dioxide-coated granular material projecting from the surface of the concrete base material is smaller than the height of the granular decorative material projecting from the surface of the concrete base material. 3. The concrete product according to claim 2, wherein the particulate decorative material comprises two or more types of particles including glass beads, and a titanium dioxide film is formed on the surface of the particulate decorative material comprising the glass beads. .