JPH0465373A - Thermally sprayed concrete block and production thereof - Google Patents

Abstract

PURPOSE:To improve the slip and wear resistances of a concrete block and to enhance safety at the time of rainfall by thermally spraying a mixture of a prescribed amt. of inorg. powder with a prescribed amt. of a high molecular powdery coating material on the concrete block. CONSTITUTION:A mixture of 10-150 pts. wt. inorg. powder of <=0.1 mm particle size with 100 pts. wt. high molecular powdery coating material is melted by heating sprayed on the surface of a concrete block and fired. The resulting thermally sprayed concrete block has high slip resistance and superior wear resistance and enhances safety at the time of rainfall.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermal sprayed concrete block and a method for manufacturing the same, and in particular has high slip resistance, excellent wear resistance, and a small coefficient of thermal expansion. The present invention relates to a thermal sprayed concrete block having an inexpensive coating layer and a method for manufacturing the same.

[Prior art] Concrete blocks can be colored using methods such as mixing pigments into uncured concrete and kneading the mixture, or painting with paint after hardening. However, concrete blocks colored with pigments , discoloration and fading due to efflorescence, and uneven coloring often occur, impairing the aesthetic appearance.

On the other hand, when painting with paint, it is difficult to obtain a sufficiently thick and robust coating film.

In order to solve these problems, the present applicant has developed a method of spraying molten polymer powder paint onto the surface of hardened cement (Japanese Patent No. 1494390, hereinafter referred to as 111 J).
, and a method of spraying molten polymer powder paint and inorganic granules onto the surface of interlocking blocks (Japanese Unexamined Patent Publication No. 63-20074, hereinafter referred to as "Prior Application II J"), and filed a patent application first. According to the prior application I, it is possible to produce a concrete block with a clear color that does not fade easily, and according to the prior application II, it is possible to produce a concrete block that has high abrasion resistance and slip resistance, and is beautiful and durable. It is possible to produce concrete blocks with excellent quality.

[Problems to be Solved by the Invention] However, in the method of spraying only the polymer powder paint in the prior application (2), it is difficult to reduce the manufacturing cost because the polymer powder paint is relatively expensive. In addition, the formed coating layer has a low slip resistance value when wet, so when used for pavement, there is a drawback that safety is reduced when driving a car or walking when it rains.

Furthermore, polymer powder coatings have a higher coefficient of thermal expansion than concrete, so if the strength of the object to be coated is low or the coating area is large, the coefficient of thermal expansion will change when the temperature changes. There is also the problem that temperature stress occurs due to the difference, making it easy for the coating layer to peel off.

On the other hand, in Prior Application II, it is stated that the polymer powder coating and the inorganic granules can be supplied either by mixing them in advance or by supplying each separately using separate devices. Since they are expensive, if a plurality of them are used, the cost of the device increases and preparation, operation, etc. are time-consuming. For this reason, it is advantageous to pre-mix and supply, but since polymer powder paints have a much lighter specific gravity than inorganic granules, less than half that, they tend to separate in the equipment, making spraying difficult. This can easily cause nozzle clogging. Furthermore, if the proportion of the inorganic particulates mixed with 100 parts by weight of the polymer powder coating is 100 parts by weight or more, it has the disadvantage that spraying is impossible.

The present invention solves the problems of Prior Application I and Prior Application 11, and provides a thermal sprayed concrete block having high slip resistance, excellent wear resistance, low coefficient of thermal expansion, and inexpensive coating layer. The purpose is to provide a manufacturing method thereof.

[Means for Solving the Problem] The thermal sprayed concrete block of claim (1) is a thermal sprayed concrete block formed by spraying and fixing a mixture of heated and melted polymer powder coating and inorganic powder onto the surface of the concrete block. The inorganic powder has a particle size of 0. i
The thermal sprayed concrete block according to claim (2), characterized in that the inorganic powder is a powder of less than 100 nm in diameter and the proportion in the mixture is 10 to 150 parts by weight per 100 parts by weight of the polymer powder coating. The manufacturing method is a thermal sprayed concrete block manufacturing method in which a mixture of heated and melted polymer powder paint and inorganic powder is sprayed onto the surface of a concrete block and fixed, and the inorganic powder has a particle size of 0. It is characterized in that the powder is less than 1 mm in size, and the proportion of the inorganic powder in the mixture is 1° to 150 parts by weight per 100 parts by weight of the polymer powder coating.

In the present invention, which will be described in detail below, the polymer powder coating is not particularly limited and various polymer powder coatings can be used, but in particular, ethylene vinyl acetate, polyethylene, polypropylene, polybutylene, By using a thermosetting epoxy paint, it is possible to form a coating layer with excellent acid resistance, chemical resistance, and abrasion resistance, which is extremely advantageous.

The inorganic powder is not particularly limited, but silica sand, calcium carbonate, crushed blast furnace slag, etc. are generally used. In the present invention, these inorganic powders have a particle size of less than 0.1 mm. Particle size of inorganic powder is 0
．． If it is 1 mm or more, it will be easy to separate from the polymer powder coating, and it cannot be used by pre-mixing with the polymer powder coating. However, if the particle size of the inorganic powder is less than 0.01 mm, it will easily scatter during thermal spraying, so it is preferable to reduce the proportion of inorganic powder with a particle size of less than 0.01 mm. In the present invention, the particle size range of the inorganic powder is preferably 0.01 mm or more and less than 0.1 mm.

In the present invention, the inorganic powder is used by being mixed with the polymer powder coating in advance, and the mixing ratio is 10 parts of the polymer powder coating.
The amount of inorganic powder is 10 to 150 parts by weight relative to 0 parts by weight. If the ratio of the inorganic powder is 10 parts by weight per 100 parts by weight of the polymer powder coating, the improvement effect by mixing and using the inorganic powder will not be sufficiently obtained, and if it exceeds 150 parts by weight, the improvement effect will not be obtained. This may adversely affect the color tone and properties of the thermally sprayed coating layer.

In the present invention, a mixture obtained by pre-mixing a polymer powder coating and an inorganic powder at a predetermined ratio (hereinafter referred to as "polymer powder coating containing inorganic powder") is conveyed by a gas flow. , this polymer powder coating is heated to a molten state. Then, a gas flow containing the molten inorganic powder-containing polymer powder paint is sprayed onto the concrete block, and the inorganic powder-containing polymer powder paint collides with the surface of the concrete block and becomes fixed, thereby forming a coating layer. Form.

Such spraying and fixing is carried out using a device, etc. that has a gas flow generating means for conveying the polymer powder coating containing inorganic powder and a means for heating and melting the polymer powder coating conveyed by the gas flow. For example, it is possible to: (1) transport a polymer powder coating containing inorganic powder in an air stream, and mix combustion gas with this air stream to thermally melt the polymer powder coating and heat the inorganic powder; Device.

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

etc. are used.

The method of the present invention can also be carried out using an apparatus in which a polymeric powder coating containing inorganic powder is introduced into a high-temperature gas stream such as combustion gas.

More specifically, the method of the invention can be carried out using conventional thermal spray equipment. Various types of thermal spraying equipment, such as gas type and plasma type, can be adopted.

In addition, if the surface of the concrete block is preheated before thermal spraying, the prevention of bubbles in the coating layer will be further ensured, and the temperature of the surface of the concrete block will approach the melting point of the polymer powder coating. Leakage of the polymer powder paint is improved, and the adhesion between the formed coating layer and the concrete block is improved.

FIG. 1 is a sectional view illustrating a state in which spraying according to the present invention is performed using a gas type thermal spraying device.

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

The inorganic powder-containing polymer powder paint 5 ejected from the outlet of the supply hole 2 is conveyed by air from the conveying air blow-off hole 3 and heated by the combustion flame 6 of the combustion gas from the combustion gas supply hole 4. The coating material is heated to 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 in which inorganic powder is uniformly dispersed.

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.
A coating layer with a smooth surface and a thickness of m, which is made by uniformly dispersing inorganic powder in a polymeric powder coating, can be formed arbitrarily.

[Effects] By mixing a predetermined proportion of inorganic powder into the polymer powder coating, it has a high sliding resistance value, a small coefficient of thermal expansion,
It has excellent abrasion resistance and can form a coating layer with a smooth surface and high adhesion. Furthermore, by using inexpensive inorganic powder, material costs can be reduced.

The inorganic powder-containing polymer powder coating is sprayed onto the surface of the concrete block in a heated and molten state and is fixed, so the coating layer of the inorganic powder-containing polymer powder coating can be efficiently coated in a short time. It can be formed as follows. Moreover, there is no need to use a solvent.

Therefore, the inorganic powder with a small particle size according to the present invention can be mixed with a polymer powder coating in a uniformly dispersed state,
Since it is difficult to separate the two, they can be pre-mixed and sprayed together as a mixture without clogging the equipment. For this reason, equipment costs are reduced, workability is improved,
Handling efficiency and productivity can be improved.

[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 it exceeds the gist thereof.

Examples 1 to 4 The surface of the concrete block shown in Table 1 was coated with a gas spraying device (manufactured by 5hori, UK) shown in Figure 1.
The coating layer materials premixed in the proportions shown in Table 1 were thermally sprayed to form a coating layer with a thickness of about 1 mm. The specific conditions are as follows.

Polymer powder coating type: Ethylene vinyl acetate Particle size: 0.08 to 0.2 mm Inorganic powder type: Thorough silica particle size: 0.01 mm or more, less than 0.1 mm Conveying air blowing amount related to thermal spray equipment: 120 ° C / m i Type of combustion gas: 25 cm distance between LP gas spray gun and concrete block Concrete block surface coronal temperature approximately 120°C Area of formed coating layer: Approximately 200~a o Ocrn' Surface condition of formed coating layer, Table 1 shows the adhesion performance, amount of wear, coefficient of thermal expansion, durability, and sliding resistance value. In addition,
The surface condition is determined by visual observation, and the adhesion performance is determined by JIS.
K 5669 Synthetic Emulsion Putty 5.11 Adhesion strength was determined by peel test.

In addition, the amount of wear was investigated by the Lahering test of asphalt pavement specifications, and the coefficient of thermal expansion was calculated by pasting a strain gauge on the surface of the coating layer and measuring the strain when changing the ambient temperature from 0 to 20 degrees Celsius. .

Durability was determined by conducting a 60-cycle cold/heat cycle test, with one cycle being 0°C x 6 hours and 50°C x 6 hours.
It was determined by examining the condition of the block after the test. In addition, the slip resistance value was investigated by STM E303 slip resistance test.

Comparative Example 1 (Prior Application I) A coating layer was formed in the same manner as in Example 1 except that no inorganic powder was used, and its various properties were investigated. The results are shown in Table 1.

Comparative Example 2 (Prior Application II) A coating layer was formed in the same manner as in Example 2, except that inorganic granules (glass beads; particle size = 0, 1 to 0, 84 mm) were used instead of inorganic powder. The formation of
Its various properties were investigated and the results are shown in Table 1.

Comparative example 3 The various properties were investigated and the results are shown in Table 1.

Comparative Example 4 The surface of the same type of hollow block as used in Example 2 was coated with acrylic paint using a brush, and its various properties were investigated, and the results are shown in Table 1.

As is clear from Table 1, the coating layer formed on the surface of the concrete block according to the method of the present invention has sufficient adhesion and has a smooth and dense surface texture. It is clear that by forming the coating layer, the abrasion resistance of the concrete block is significantly improved, the slip resistance is increased, the coefficient of thermal expansion is improved, and the durability is increased.

[Effects of the Invention] As detailed above, the thermal sprayed concrete block of the present invention has excellent abrasion resistance, acid resistance, chemical resistance, durability, etc. within the thickness range.

■ The colors are clear and will not fade due to efflorescence.

■ Extremely high adhesion to concrete blocks.

■It is extremely dense and has excellent smoothness.

■ Slip resistance value is excellent for safety when running and walking.

■ It has a small coefficient of thermal expansion and can be used for low-strength concrete blocks and thermal spraying on large areas.

Provided is a thermal sprayed concrete block having a coating layer formed on its surface that has superior features such as: Furthermore, since the inorganic powder and the polymeric powder coating can be mixed in advance, material costs and equipment costs can be reduced, workability and productivity can be improved, and inexpensive products can be provided.

According to the method for manufacturing a thermal sprayed concrete block of the present invention, the above-mentioned high-performance thermal sprayed concrete block can be easily manufactured.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating the method for manufacturing a thermal sprayed concrete block of the present invention. DESCRIPTION OF SYMBOLS 1... Thermal spray gun nozzle, 2... Supply hole, 3... Conveying air blow-off hole, 4... Combustion gas supply hole, 5... Polymer powder coating containing inorganic powder, 6... Combustion flame, 7... Concrete block, 8... Covering layer.

Claims (2)

[Claims] (1) A thermal sprayed concrete block formed by spraying and fixing a mixture of heated and melted polymer powder paint and inorganic powder onto the surface of a concrete block, the inorganic powder being a powder with a particle size of less than 0.1 mm. The ratio in the mixture is 1 part by weight of the inorganic powder to 100 parts by weight of the polymer powder coating.
A thermal sprayed concrete block characterized by having a content of 0 to 150 parts by weight. (2) A method for producing a thermal sprayed concrete block in which a mixture of a heated and melted polymer powder coating and an inorganic powder is sprayed onto the surface of the concrete block and fixed, the inorganic powder having a particle size of less than 0.1 mm. 1. A method for producing a thermal sprayed concrete block, characterized in that the ratio in the mixture is 10 to 150 parts by weight of inorganic powder to 100 parts by weight of polymer powder coating.