JPH0479988B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a concrete product formed by forming a coating layer on a concrete base material and a method for manufacturing the same.

(Problems to be solved by conventional techniques and inventions) In recent years, lightweight aerated concrete,
Demand for various concrete products such as precast concrete is increasing, and in response to this demand, some concrete products are given a mirror finish by forming a coating layer on their surfaces to improve their appearance. In this case, since conventional paint layers were formed using solvent-based paints, volatile solvent components remaining in the paint layer gradually migrated from the surface of the paint layer to the atmosphere over time. There was a problem in that the traces of the particles left behind on the surface of the coating layer caused the glossiness of the surface of the coating layer to deteriorate over time.

In addition, the surface of concrete base materials is generally rough with countless pinholes formed on it, so simply applying paint to this surface and curing it will not make the surface of the paint layer smooth. The desired level of gloss cannot be obtained. Therefore, in order to apply makeup to concrete products using a coating layer with a mirror finish,
After removing efflorescence, laitance, dust, dirt, etc. from the surface of the concrete base material in advance, a primer coating is applied to the surface of this concrete base material,
I then apply a top coat of solvent-based paint on top of that. In this case, simply applying the primer paint will not make the surface of the primer layer sufficiently smooth.
Before applying the topcoat, the surface of the undercoat layer is smoothed by repeating the labor-intensive process of applying putty or surfacer to the surface of the undercoat layer and polishing it after it hardens. I tried to improve the smoothness of the surface.

However, in the conventional coating film forming method described above, in order to smooth the surface of the coating film (top coat layer),
The labor-intensive process of applying putty to the surface of the undercoat layer and polishing it after it hardens must be repeated several times, which is not only extremely troublesome, but also requires a large amount of time for the putty and Surfacer to harden. However, there was a problem in that the manufacturing efficiency generally decreased.

The present invention aims to solve these problems, and its primary purpose is to provide a concrete product that can maintain good gloss on the surface of the coating layer over a long period of time. A second object of the present invention is to provide a method for manufacturing concrete products that can improve manufacturing efficiency while increasing the surface gloss of the coating layer.

[Structure of the Invention] (Means for Solving the Problems) The concrete product of the present invention has a coating layer formed on a concrete base material, and the coating layer is formed with a solvent-free paint. The gloss of the surface thereof is set to 75, preferably 85 or more at 60° specular reflection, and the thickness of the coating layer is set to 100 to 5000 μm.

The method for producing a concrete product of the present invention also includes a step of applying a solvent-free paint onto a concrete base material to form an uncured paint layer of the solvent-free paint, and a step of forming a smooth coating layer on the uncured paint layer. smoothing the surface of the uncured coating layer by overlapping plastic sheets and pressing the plastic sheets with a pressing body; and peeling off the plastic sheet after curing the uncured coating layer. The steps to be taken are executed in order.

(Function) According to the concrete product of the present invention, since the coating layer is formed of a solvent-free paint, the coating layer does not contain any volatile solvent components, and the volatilization of the solvent components as in the conventional case is prevented. There is no risk of deterioration of gloss due to Moreover, the thickness of the coating layer is set at 100 to 5000 μm in consideration of weather resistance, durability, water resistance, etc., and this combined with the above-mentioned circumstances results in an excellent initial gloss level (60°). Specular reflection of 85 or higher) can be maintained for a long period of time.

Further, according to the method for producing concrete products of the present invention, before the coating layer is cured, a smooth plastic sheet is superimposed on the uncured coating layer and the plastic sheet is pressed with a pressing body, so that the uncured coating layer is cured. The surface of the cured coating layer is smoothed along the smooth surface of the plastic sheet. Therefore, the surface of the coating layer can be made the same smooth surface as the surface of the plastic sheet by an extremely simple method of overlapping the plastic sheets and pressing with a pressing body, and the putty can be applied before forming the coating layer. There is no need to repeat painting and polishing.

(Example) Hereinafter, a first example of the present invention will be described based on FIGS. 1 to 6.

First, the completed form of the concrete product will be explained based on FIGS. 1 and 2. Reference numeral 1 denotes a concrete base material made of, for example, lightweight cellular concrete, precast concrete, etc., and this concrete base material 1 is formed into a rectangular plate shape so as to constitute, for example, a wall panel of a building. 2 is an undercoat layer formed on the surface of the concrete base material 1, and this undercoat layer 2
As described below, is an undercoat paint (for example, the product name "Mizeron Sheila" manufactured by Mitsui Kinzoku Paint Chemicals Co., Ltd.)
It is formed by coating the surface of the concrete base material 1 and rubbing it in so as to fill the pinholes on the surface. Reference numeral 3 denotes a coating layer formed as an overcoat on the undercoat layer 2, and this coating layer 3 is applied directly to the undercoat layer 2 without applying putty coating or polishing to the surface of the undercoat layer 2 as in conventional methods. A solvent-free paint (for example, a two-component polyurethane commercially available under the trade name "Mizeron S-100" manufactured by Mitsui Kinzoku Paint Chemical Co., Ltd.) is applied to the surface as a top coat, and the surface of the coating layer 3 is coated with the uncured paint. It is formed by smoothing it using a plastic sheet 14 and a pressing roller 16, as will be described later.
As a result, the thickness of the coating layer 3 can be increased from 100 to 100.
The surface gloss of the coating layer 3 is set to 75, preferably 85 or higher at 60° specular reflection. Here, 85 or more at 60° specular reflection means JIS
This refers to the value obtained by measuring the surface of coating layer 3 by irradiating light at an angle of 60° based on the method specified in Z8741.

Next, the undercoat layer forming apparatus 4 for forming the above-mentioned undercoat layer 2 will be explained based on FIG. 3. 5 is a feed roller for feeding the concrete base material 1 in the direction of arrow A;
6a and 6b, the base coat 7 is applied to the concrete base material 1.
a pair of coating rollers 8 for rubbing the primer paint 7 onto the surface of the concrete base material 1; 9 and 10 are located below the coating roller 6 and the reverse roller 8, respectively; This is a back-up roller that supports the concrete base material 1.

On the other hand, based on FIG. 4, the coating layer smoothing device 11 for smoothing the coating layer 3 when it is not cured will be described. Reference numeral 12 is a conveyor belt driven by a drive roller 13; The concrete base material 1 placed above is sent in the direction of arrow B. Reference numeral 14 denotes a plastic sheet stretched under tension on a frame 15, and this plastic sheet 14 is arranged so as to overlap the uncured coating layer 17 on the concrete base material 1. In this case, the plastic sheet 14 is made of a polypropylene sheet, a polyethylene sheet, etc., which has excellent releasability to the coating layer 3 of the solvent-free paint.
Such as vinyl chloride sheet. Reference numeral 16 denotes a rubber pressing roller which is a pressing body for pressing the plastic sheet 14 from above.
rotates in the forward direction of the advancing direction of the concrete base material 1 (in the direction of arrow C).

Next, a procedure for forming the coating layer 3 on the surface of the concrete base material 1 using each of the above-mentioned devices 4 and 11 will be explained. First, as a base preparation, the surface of the concrete base material 1 is cleaned with a wire brush, sandpaper, etc.
The surface of the concrete base material 1 is cleaned by rubbing with a cloth or the like to remove efflorescence, laitance, dust, dirt, etc. from the surface of the concrete base material 1. Next, the concrete base material 1 is inserted between the feed roller 5 and the coating rollers 6a, 6b in FIG. 3 and fed in the direction of arrow A. At this time, both coating rollers 6a and 6b rotate in opposite directions (directions of arrows D and F), and both coating rollers 6a and 6b rotate in opposite directions (directions of arrows D and F).
From between a and 6b, apply the base paint 7 (for example, the product name "Mizeron Sealer" manufactured by Mitsui Kinzoku Paint Chemical Co., Ltd.)
is applied to the surface of the concrete base material 1. The applied primer paint 7 is rubbed into the surface of the concrete base material 1 by a reverse roller 8 rotating in a direction (direction of arrow G) opposite to the direction of travel (direction of arrow A), so that the surface has no pinholes. A coating layer 2 is formed (see FIG. 5a). After the undercoat layer 2 formed in this way is cured, the surface of the undercoat layer 2 is coated with a solvent-free paint (for example, a two-component paint commercially available under the trade name "Mizeron S-100" manufactured by Mitsui Kinzoku Paint Chemical Co., Ltd.). Polyurethane) is applied to form an uncured coating layer 17 of a solvent-free coating as shown in FIG. 5b. In this case, the solvent-free paint may be applied using an automatic coating machine such as a roller coater equipped with the above-mentioned coating rollers 6a and 6b, a curtain flow coater, or a spray coater. There is no need to repeat the conventional putty application and polishing before application. Immediately after applying the solvent-free paint, as shown in FIG.
4 are stacked one on top of the other without wrinkles, and in this state, the concrete base material 1 is placed on the conveyor belt 12. At this time, the plastic sheet 14 is kept under tension on the frame 15 to prevent wrinkles from forming. Then, the concrete base material 1 placed on the conveyor belt 12 is sent along with the plastic sheet 14 by the conveyor belt 12 in the direction of arrow B, but on the way, the concrete base material 1 is pressed against the pressing roller 16 (rotation direction is in the direction of arrow C). )
When passing under the plastic sheet 14, the uncured coating layer 17 is pressed by the pressure roller 16 onto the plastic sheet 14.
The surface of the uncured coating layer 17 is sequentially smoothed along the lower surface of the plastic sheet 14 by this pressing action (see FIG. 5c).
Moreover, the layer thickness is set to 100 to 5000 μm. In this case, the surface of the plastic sheet 14 interposed between the uncured coating layer 17 and the pressure roller 16 has extremely high smoothness, and the surface of the plastic sheet 14 with high smoothness is left uncured by the pressing action of the pressure roller 16. Since it is transferred onto the surface of the cured coating layer 17, the surface smoothness of the uncured coating layer 17 becomes extremely high. After curing the uncured coating layer 17 smoothed in this way, the plastic sheet 14 is peeled off to obtain a smooth coating layer 3. The gloss level of the surface is 75 or higher at 60° specular reflection. Incidentally, the curing reaction of the solvent-free paint may be accelerated by curing the uncured coating layer 17 at an atmospheric temperature of, for example, 150° C. or lower.

In this case, since the uncured coating layer 17 is cured with the plastic sheets 14 stacked on top of each other, if the uncured coating layer 17 is formed using a conventional solvent-based coating, the solvent in the coating The volatilization of the components is prevented by the plastic sheet 14, and curing does not proceed sufficiently or curing occurs abnormally, so that the expected coating layer cannot be obtained.

However, in this example, the uncured coating layer 1
7 is formed with a solvent-free paint, even if the plastic sheet 14 is superimposed on the surface of the uncured paint layer 17, the uncured paint layer 1
The curing reaction of No. 7 proceeds smoothly without any inhibition, and a coating layer 3 having a good smooth surface is obtained.

According to the manufacturing method described above, the surface of the coating layer 3 can be easily smoothed by the plastic sheet 14 and the pressing roller 16 when it is not cured.
The surface of the undercoat layer 2 does not need to be putty-coated and polished as in the past, and the effort of repeating putty-coating and polishing can be saved, and manufacturing efficiency can be greatly improved. Moreover, the plastic sheet 14 has extremely high smoothness.
The surface of the uncured coating layer 17 (coating layer 3) is transferred to the surface of the uncured coating layer 17 (coating layer 3) by the pressing action of the pressing roller 16, so the smoothness of the surface of the uncured coating layer 17 (coating layer 3) This makes it possible to easily obtain a coating layer 3 with an extremely high gloss of 85 or higher at 60° specular reflection. Furthermore, even if the surface (upper surface) of the undercoat layer 2 is somewhat uneven as shown in FIG. 6, the surface of the coating layer 3 is smoothed based on the pressure roller 16, There is an advantage that the surface of the coating layer 3 can be reliably smoothed regardless of the level of smoothness, and the quality of the glossiness of the coating layer 3 can be stabilized. On the other hand, in conventional coating film formation methods, the top coat is simply applied to the undercoat layer, so the surface smoothness of the topcoat layer is dependent on the surface smoothness of the undercoat layer. There is.

In addition, in the above embodiment, the coating layer 3 is formed on the undercoat layer 2, so that the adhesion strength of the coating layer 3 is increased and peeling, cracking, etc. of the coating layer 3 is prevented for a long period of time. It can prevent scratches and improve durability.
Moreover, since the undercoat layer 2 is formed by rubbing the undercoat paint 7 into the surface of the concrete base material 1, the pinholes on the surface of the concrete base material 1 are filled with the undercoat paint 7, and the surface of the undercoat layer 2 is This can contribute to improving the smoothness of the surface of the coating layer 3.

In addition, according to the concrete product having the above-described structure, since the coating layer 3 is formed of a solvent-free paint, the coating layer 3 does not contain any volatile solvent components, and unlike conventional solvent components. There is no risk of gloss deterioration due to volatilization. Moreover, since the thickness of the coating layer 3 is set to 100 to 5000 μm in consideration of weather resistance, durability, water resistance, etc., this combined with the above-mentioned circumstances results in an excellent initial gloss level (60 μm). 85 or higher in specular reflection) can be maintained for a long period of time.

In the above embodiment, the surface of the coating layer 3 was exposed to the atmosphere, but for example, as in the second embodiment of the present invention shown in FIG.
It is also possible to form a top coat layer 18 by applying a coated top coat to the surface of the paint film layer 3 after peeling off the top coat layer 18. In this case, the top coat that forms the top coat layer 18 may be, for example, a fluorine-based paint that cures at room temperature, a silicone-acrylic paint, a modified silicone-based paint, a urethane-based paint, an acrylic urethane-based paint, etc., which are relatively durable. It is preferable to use a paint with excellent weather resistance. In this way, the coating layer 3
can be protected by the top coat layer 18, increasing durability and
Weather resistance etc. are extremely excellent.

In the first embodiment, a so-called roller coater having coating rollers 6a and 6b was used to apply the undercoating paint 7 to the surface of the concrete base material 1, but the present invention is not limited to this, and for example, a curtain flow coater, The coating may be performed using another automatic coating machine such as a spray coater. Also,
Although the reverse roller 8 is used to rub the applied undercoat 7 onto the surface of the concrete base 1, the present invention is not limited thereto. It is also possible to apply pressure and rub. Furthermore, in each of the above embodiments,
Although the undercoat layer 2 is interposed between the coating layer 3 of the solvent-free paint and the surface of the concrete base material 1, for example, by applying the solvent-free paint directly to the surface of the concrete base material 1, The mold paint may be rubbed in with a reverse roller, etc. In this case as well, by rubbing the solvent-free paint into the pinholes on the surface of the concrete base material 1, the coating layer of the solvent-free paint and the concrete base material are separated. 1 can be ensured, and the surface of the coating layer can also be sufficiently smoothed by the method described above. Further, in the first embodiment, from the viewpoint of preventing wrinkles from forming on the plastic sheet 14 overlaid on the surface of the uncured coating layer 17, the plastic sheet 14 is placed on the frame 1.
For example, a plastic sheet wound around a roll may be unwound from the roll and overlaid on the surface of the uncured coating layer 17.

In the above example, the gloss level of the surface of the coating layer 3 was set to 75 or higher at 60° specular reflection to improve the appearance, but for those used in places where surface gloss level is not required. , even those with a gloss level of 75 or less can be used satisfactorily.

In addition, the present invention can also be applied to concrete products other than wall panels, such as by using a press mold instead of the pressure roller 16 of the first embodiment as a pressing body that presses from above the plastic sheet 14. Various modifications are possible without departing from the gist of the present invention.

[Effects of the Invention] As is clear from the above explanation, according to the concrete product of the present invention, since the coating layer is formed of a solvent-free paint, there is no volatile solvent component in the coating layer. There is no risk of deterioration in gloss due to volatilization of solvent components as in conventional cases. Moreover, the thickness of the coating layer is set at 100 to 5000 μm in consideration of weather resistance, durability, water resistance, etc.
Coupled with the above-mentioned circumstances, the initially excellent glossiness (75 or higher at 60° specular reflection) can be maintained for a long period of time.

Furthermore, according to the method for manufacturing concrete products of the present invention, before the coating layer is cured, a smooth plastic sheet is superimposed on the uncured coating layer and the plastic sheet is pressed by a pressing member from above. With a simple method, the surface of the paint layer can be made as smooth as the surface of the plastic sheet, eliminating the need to repeatedly apply putty and polishing before forming the paint layer, greatly improving manufacturing efficiency. can. Furthermore, since the extremely smooth surface of the plastic sheet is transferred to the surface of the coating layer by the pressing action of the pressing body, the smoothness (gloss) of the surface of the coating layer can be extremely high. Furthermore, since the coating layer is formed using a solvent-free paint, even if a plastic sheet is placed on the surface of the uncured coating layer, the curing reaction of the uncured coating layer will proceed smoothly without being inhibited in any way. However, a coating layer with a good smooth surface can be obtained.

[Brief explanation of drawings]

Figures 1 to 6 show the first embodiment of the present invention. Figure 1 is a partially enlarged sectional view of a concrete product, Figure 2 is a partially cutaway perspective view of the same, and Figure 3 is a bottom view of the concrete product. FIG. 4 is a perspective view of the main parts of the coating layer forming device; FIG. 4 is a perspective view of the main parts of the coating layer smoothing device; FIGS.
Figure c is a process diagram for explaining the manufacturing process of the coating layer, Figure 6 is an enlarged longitudinal cross-sectional view of the main part, and Figure 7 is a diagram equivalent to Figure 1 showing the second embodiment of the present invention. be. In the drawing, 1 is the concrete base material, 2 is the undercoat layer,
3 is a coating layer, 4 is an undercoat layer forming device, 6 is a coating roller, 7 is an undercoat paint, 8 is a reverse roller, 11 is a coating layer smoothing device, 14 is a plastic sheet, 15 is a frame, 16 is a A pressing roller (pressing body), 17 is an uncured coating layer, and 18 is an overcoat layer.

Claims (1)

[Scope of Claims] 1. A product in which a paint film layer is formed on a concrete base material, wherein the paint film layer is formed with a solvent-free paint so that the gloss level of the surface thereof is 75 or more at 60° specular reflection. Set the thickness of the coating layer to 100 to 5000μ
A concrete product characterized by being set at m. 2. The concrete product according to claim 1, wherein the coating layer is formed on an undercoat layer formed on the surface of a concrete base material. 3. A step of applying a solvent-free paint onto a concrete base material to form an uncured paint film layer of the solvent-free paint, and a step of overlaying a smooth plastic sheet on the uncured paint film layer and depositing a layer on top of the plastic sheet. A step of smoothing the surface of the uncured coating layer by pressing it with a pressing body, and a step of peeling off the plastic sheet after the uncured coating layer has been cured are sequentially executed. How the product is manufactured. 4. The method for producing a concrete product according to claim 3, wherein the coating layer has a thickness of 100 to 5000 μm. 5. The method for manufacturing a concrete product according to claim 3 or 4, wherein the coating layer is formed on an undercoat layer formed on the surface of a concrete base material. 6. The undercoat layer according to claim 5, wherein the undercoat layer is formed by applying an undercoat paint to the surface of the concrete base material and then rubbing the undercoat paint onto the surface of the concrete base material. Method of manufacturing concrete products.