JPH0340978A - Surface-coated concrete block and its production - Google Patents

Abstract

PURPOSE:To improve the durability of a concrete block by spraying a polymeric powder paint or the paint and an inorg. granular material on the surface of the block and sticking the materials to the surface. CONSTITUTION:A gas-type thermal spraying device is used. A polymeric powder paint 5 of PE, etc., is injected from the injection port 2 of a thermal spraying gas nozzle 1, entrained by the air from a carrier air blowoff hole 3, heated by the flame 6 of the combustion gas from a combustion gas supply hole 4 and melted. The molten paint is allowed to collide with the surface of a concrete block 7 and stuck to the surface to form a coating layer 8 of the paint. The thickness of the layer 8 is easily adjusted by the spraying time, and a thickness of 0.2-5mm is obtained by one spraying. Alternatively, a coating layer 8 contg. 100 pts.wt. of the paint and <=75 pts.wt. of an inorg. granular material such as glass beads having 0.01-2mm diameter can be also formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a surface-coated concrete block and a method for manufacturing the same, which has a particularly thick and robust coating layer and is very easy to remove stains such as graffiti. This invention relates to a surface-coated concrete block that can be dropped into a concrete block and a method for producing the same.

[Prior Art] Among concrete blocks, decorative concrete blocks are mainly used as civil engineering structures and walls, or as a part thereof, and have a greater aesthetic element than hollow concrete blocks.

Conventionally, surface finishing methods such as polishing, cutting, washing, pounding, and splitting have been commonly used as decorative finishing methods for such decorative concrete blocks. Also,
In some cases, additional coloring is applied to improve cosmetic properties, but in this case, the coloring method involves mixing pigments into uncured concrete, kneading and coloring, or painting after curing using paint, etc. There are ways to do this.

[Problems to be Solved by the Invention] In conventionally provided decorative concrete blocks, when the surface is not colored or when it is colored with pigment, the aesthetic appearance is deteriorated due to discoloration and fading due to efflorescence and color unevenness. This often leads to a decline. On the other hand, when painting with paint or the like, a sufficiently thick and robust coating film could not be obtained because it was difficult to obtain a desired thick film and there were problems with adhesion. In other words, the surface coating of decorative concrete blocks is often applied not only for aesthetic purposes but also for the purpose of improving waterproofness and abrasion resistance, and the conventional coating methods described above do not improve the adhesion of the coating layer formed. The actual situation is that there is a problem with the thickness of the coating layer, and good characteristics cannot be obtained.

In addition, decorative concrete blocks may become dirty due to graffiti on the surface with oil-based sprays or oil-based pens, or organic matter adhering to them, but conventional surface-coated concrete blocks can be used in such cases. It is not easy to remove the dirt that has adhered to it, and removing it requires complicated treatments and a great deal of effort, such as polishing the surface and painting the entire surface to cover up the dirt. .

[Means for Solving the Problem] The surface-coated concrete block of claim (1) is obtained by spraying a heat-melted polymer powder paint or a heat-melt polymer powder paint and inorganic granules onto the surface of the concrete block. The method for producing a surface-coated concrete block according to claim (2), characterized in that the surface-coated concrete block is coated with heat-melted polymer powder paint or heat-melted polymer powder paint and It is characterized by spraying and fixing inorganic granules.

By the way, the present applicant has developed a method of spraying molten polymer powder paint onto the surface of a hardened cement body by thermal spraying, and has previously filed a patent application (“Japanese Patent Publication No. 63-44715 1 et seq., r Prior Application 1 ). According to the method of the prior application, it is possible to form a thick coating film with a clear color and less fading on the surface of the hardened cement body.

As a result of various experiments, the present inventors have found that by applying the technology of the prior application, a thick wall with a clear color that is less likely to fade on the surface of hardened hollow concrete blocks, decorative concrete blocks, etc. The inventors have discovered that this surface coating film can be very easily removed from stains caused by graffiti, etc., and have completed the present invention.

The present invention will be explained in detail below.

In the present invention, examples of the concrete block forming the coating layer include a hollow concrete block or a decorative concrete block.

In the present invention, a heated and melted polymer powder coating or a heated and melted polymer powder coating and inorganic granules are sprayed and fixed onto the surface of such a concrete block.

There are no particular restrictions on the polymer powder coating, and various types of polymer powder coatings can be used. However, in order to obtain surface-coated concrete blocks with excellent stain removal properties and surface smoothness, polyethylene, polypropylene, It is preferable to use polybutylene or the like.

There are no particular restrictions on the inorganic granules, including glass peas,
Silica sand, quartz particles, sand, crushed blast furnace slag, metal particles, etc. can be used. Among these, glass beads, metal particles,
These inorganic granules, which are preferably crushed blast furnace slag, must have a certain particle size,
There is a suitable range for the blending ratio, and the particle size is in the range of 0601 to 2 mm, and the blending ratio is 75 parts by weight or less of amorphous granules per 100 parts by weight of polymer granule paint, especially 10 to -5
It is preferable to set it as a 0 weight part. Incidentally, if the particle size of the inorganic particles is less than 0.01 mm, it will be difficult to form a homogeneous coating film, and if it exceeds 2 mm, the surface smoothness and stain removal properties will deteriorate. Furthermore, if the blending ratio exceeds 75 parts by weight based on 100 parts by weight of the polymer granule paint, surface smoothness and stain removal properties will deteriorate.

In the present invention, the polymer powder coating or the polymer powder coating containing inorganic particulates is conveyed by a gas stream and heated to melt the polymer powder coating. Then, a gas flow containing the molten polymer powder coating or inorganic granule-containing polymer powder coating is sprayed onto the concrete block, and the polymer powder coating or inorganic granule-containing polymer powder coating is applied to the concrete block surface. A coating layer is formed by colliding with and fixing.

Such spraying and fixing is carried out using an apparatus having a gas flow generating means for conveying the polymer powder coating or the polymer powder coating containing inorganic particulates, and a means for heating and melting the polymer powder coating conveyed by the gas flow. For example, ■: A polymeric powder coating or a polymeric powder coating containing inorganic particulates is conveyed in an air stream, and combustion gas is mixed with this air stream. A device that heats a molecular powder coating or a polymer powder coating and heats an inorganic particulate material.

■: A device that uses plasma instead of combustion gas in the device described in ■.

A hat is used.

Furthermore, the method of the present invention can also be carried out using an apparatus in which a polymer powder coating or polymer powder coating and inorganic particulate matter are dispersed and immersed in a high-temperature gas flow such as combustion gas. can.

More specifically, the method of the invention can be carried out using conventional thermal spray equipment. thermal spray equipment alfffi
Various types of gas type and plasma type can be used.

In addition, when inorganic granules are used together with a polymer powder coating in the present invention, the polymer powder coating and the inorganic granules may be mixed in advance and supplied from a supply device, or they may be supplied from a separate device. It's okay.

In addition, if the surface of the concrete block is preheated before thermal spraying, the prevention of air bubbles in the coating layer will be further ensured, and the wetting of the concrete block surface with the resin will be improved, allowing the formation of nitrogen. The adhesion between the layer and the concrete block is improved.

FIG. 1 is a sectional view illustrating a state in which a surface-coated concrete block of the present invention is manufactured using a gas spraying apparatus.

In FIG. 1, reference numeral 1 denotes a thermal spray gun nozzle of a thermal spraying apparatus, which has a triple-pipe structure having a supply hole 2 for polymer powder coating, a conveying air blow-off hole 3, and a combustion gas supply hole 4.

The polymer powder paint 5 ejected from the injection port of the polymer powder paint supply hole 2 is conveyed by air from the conveyance air blow-off hole 3, and the combustion flame 6 of the combustion gas from the combustion gas supply hole 4 is conveyed. It is heated and becomes a molten state, collides with the surface of the concrete block 7, and adheres to the surface to form a coating layer 8 of polymer powder paint.

The thickness of the coating layer 8 to be formed can be easily adjusted by changing the thermal spraying time, and according to the method of the present invention, a thickness of 0.2 to 5 m can be formed by one thermal spraying process.
The N layer of a polymer powder coating or a polymer powder coating containing inorganic particulates having a thickness of m can be arbitrarily formed.

[Function] In the present invention, the polymer powder coating or the polymer powder coating containing inorganic particulates is sprayed onto a concrete block in a heated and molten state and fixed thereon. Therefore, a surface-coated concrete block having a coating layer of a thick polymer powder coating or a polymer powder coating containing inorganic particulates can be produced in a short time. Moreover, there is no need to use a solvent.

Moreover, the formed coating layer firmly adheres to the concrete block with high adhesion, and its surface is extremely smooth, and graffiti caused by oil-based or water-based paints can be easily removed.

[Examples] The present invention will be described in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Examples 1 to 3 The first layer was applied to the surface of a hardened, air-dried hollow concrete block (Example!, 2) or decorative concrete block (Mikage - Basic 80 - Decorative block for digging) (Example 3).
A coating layer having a thickness of about 1 mm was formed using the gas spraying apparatus shown in the figure (manufactured by 5hori, UK). The specific conditions are as follows.

Polymer powder coating type: Ethylene vinyl acetate particle size
: 0.08~0.2mm inorganic granular material Type: Fine silica sand grain Size: O,OS~0.15n+m Transfer air flow rate related to thermal spraying equipment: 120 II/tin Combustion gas type: LP gas spray gun and concrete block Distance between: Approximately 20 cm Area of the formed coating layer: Approximately 800 crn'' The surface of the formed coating layer exhibits a vivid color tone, and this color tone does not easily fade and is extremely solid, and the surface is extremely It was smooth, had elasticity, and had a good feel.

Table 1 shows the surface condition, adhesion performance, stain removal property, and water permeability of the formed coating layer.

The surface condition was examined by visual observation, and the adhesion performance was determined by J.
IS K 5669 Synthetic resin emulsion putty 5
．． No. 11 adhesion strength was examined by peel test. In addition, the stain removal property was examined by writing an x on the block surface using an oil-based pen, and checking how the stain was removed by rubbing it with a cloth soaked in thinner or acetone.
Tested according to IS A3406 Cavity Concrete Block 6.3 Water Permeability Test.

Comparative Example 1 The various properties of the decorative concrete block used in Example 3 were investigated in the same manner as in Example 3 without surface coating, and the results are shown in Table 1.

Comparative Example 2 The surface of the decorative concrete block used in Example 3 was coated with acrylic paint using a brush to a thickness of 0. A coating film of 1 mm thickness was formed and its various properties were investigated in the same manner as in Example 3, and the results are shown in Table 1.

′! Table s1 shows that the coating layer formed on the surface of a hollow concrete block or decorative concrete block according to the method of the present invention has sufficient adhesion, has a smooth and dense surface texture, and has excellent dirt removal properties. It is clear that the material is excellent and also has excellent waterproof properties.

[Effects of the Invention] As detailed above, according to the surface-coated concrete block of the present invention, (1) it is thick and has excellent waterproofness, acid resistance, chemical resistance, etc.;

■ The colors are clear and almost never fade.

■ Extremely high adhesion to concrete blocks.

■Smooth surface, no bubbles, etc., and extremely dense.

■ Graffiti and other stains caused by oil-based and water-based paints can be removed very easily.

Provided is a surface-coated concrete block having a coating layer formed on its surface and having excellent features such as the following.

Therefore, the surface-coated concrete block of the present invention is highly durable, and has the advantage that it is possible to erase graffiti, etc., which conventionally required a lot of effort, in a very easy and complete manner. It is extremely useful industrially as a material for high-performance concrete structures or secondary concrete products.

According to the method for manufacturing a surface-coated concrete block of the present invention, a high-performance coating layer as described above can be easily formed on the surface of a concrete block.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating the method for manufacturing the surface of a concrete block according to the present invention. l... Thermal spray gun nozzle, 2... Polymer powder paint supply hole, 3... Conveying air blow-off hole, 4... Combustion gas supply hole, 5... Polymer powder paint, 6... - Combustion flame, 7... Concrete block, 8... Polymer powder paint coating layer.

Claims (2)

[Claims] (1) A surface-coated concrete block characterized by being formed by spraying and fixing a heat-melted polymer powder paint or a heat-melt polymer powder paint and inorganic granules onto the surface of a concrete block. (2) A method for producing a surface-coated concrete block, which comprises spraying and fixing a heated and melted polymer powder coating or a heated and melted polymer powder coating and inorganic granules onto the surface of a concrete block.