JPH0453834B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a painted concrete product comprising a coating layer formed on a concrete base material.

(Conventional technology) In recent years, demand for various concrete products such as lightweight aerated concrete (hereinafter referred to as ALC) and precast concrete has been increasing as building materials. It is being done to improve the appearance by forming and giving it a mirror finish. This type of painted concrete products include, for example, ALC panels and precast concrete panels that have been painted to give a mirror finish, and the conventional general manufacturing methods thereof are as follows.

First, after the surface of the concrete base material is subjected to a base treatment, an undercoat paint is applied to the surface of this concrete base material. Since concrete products generally have a rough surface with numerous irregularities, simply applying an undercoating paint will not make the surface of the undercoat layer sufficiently smooth. For this reason, we then applied putty to the surface of the undercoat layer, polished it after it hardened, then applied putty or Surf Acer again, and after hardening, we polished it with finer paper. Repeat to smooth the base coat. Then, paint is applied again onto the thus smoothed undercoat layer to obtain a mirror-like coating layer.

(Problems to be Solved by the Invention) However, in the conventional painted concrete products described above, in order to smooth the coating layer, putty or Surf Acer is applied to the surface of the undercoat layer and then polished after hardening. Not only is it extremely troublesome as the tedious and time-consuming work has to be repeated over and over again, but it also takes a long time to harden the putty, lowering manufacturing efficiency and resulting in higher costs overall.

The present invention aims to solve these problems and provides a coated concrete product that can easily form a coating layer with excellent smoothness and can be manufactured at low cost.

[Structure of the Invention] (Means for Solving the Problems) The painted concrete product of the present invention has a coating layer formed on a concrete base material, and a pressed body formed by overlapping the coating layer when the coating layer is not cured. The present invention is characterized by a structure comprising a peelable plastic sheet that smoothes the coating layer by being pressed by the plastic sheet and protects the coating layer after curing.

(Function) According to the above means, since the coating layer on the concrete base material includes a plastic sheet that is overlapped and pressed by a pressing body before it hardens, the surface of the coating layer is a smooth surface of the plastic sheet. is smoothed equivalently to Therefore, by simply overlapping the plastic sheets and pressing them with a pressing body, the surface of the coating layer can be made as smooth as the surface of the plastic sheet. There is no need for repeated polishing, and manufacturing operations, particularly the smoothing of coating layers, become significantly easier than in the past. Moreover, this plastic sheet not only contributes to the smoothing of the paint film layer, but also has the function of protecting the paint film layer after hardening. By peeling off the plastic sheet, it is possible to prevent the coating layer from being damaged and losing its long-awaited smoothness during transport or assembly of the concrete product.

(Example) Hereinafter, one example of the present invention will be described based on the drawings.

First, the completed state of the concrete product will be explained based on FIGS. 1 and 2. In this embodiment, the concrete base material 1 is, for example, an ALC panel or a press cast concrete panel for constructing the outer wall of a building, and has a rectangular plate shape. An undercoat layer 2 is formed on the surface of the concrete base material 1, and as described later, this is formed by applying an undercoat paint to the surface of the concrete base material 1 and rubbing it in so as to fill in the unevenness of the surface. has been done. A coating layer 3 is formed as an overcoat on the undercoat layer 2. This is formed by applying, for example, a solvent-based paint to the surface of the undercoat layer 2 without puttingty coating or polishing as in conventional methods, and its thickness is set to, for example, 100 μm to 5000 μm. ing.
Note that this thickness is most preferably in the range of 100 μm to 3000 μm. A smooth plastic sheet 4 is removably superimposed on the surface of the coating layer 3. As will be described later, these are overlapped when the coating layer 3 is uncured, and the coating layer 3 is cured in this state, and the surface of the cured coating layer 3 is thereby protected. This plastic sheet 4 has an extremely fine porous structure in order to volatilize the solvent contained in the coating layer 3. For example, a small amount of water-soluble resin (such as polyethylene glycol) is added to an organic solvent-based comparative forming resin. It is made into a sheet by kneading it to ensure sufficient dispersion, and then making it porous by dissolving and removing the above water-soluble resin with water.The pores are extremely fine, so the sheet as a whole has sufficient smoothness. has.

Next, a method for manufacturing the above-mentioned constituent panel will be described. First, the undercoat layer forming device 5 forms the undercoat layer 2.
To explain this based on FIG. 3, this device 5 includes a feed roller 6 for feeding the concrete base material 1 in the direction of arrow A, and a pair of coatings for applying the primer paint 7 to the surface of the concrete base material 1. roller 8
a, 8b, a reverse roller 9 for rubbing the primer paint 7 into the surface of the concrete base material 1, and a back up roller 10 located below the coating rollers 8a, 8b and the reverse roller 9 and supporting the concrete base material 1; A group of rollers is provided.

Here, the concrete base material 1 whose surface has been rubbed with a wire brush, sandpaper, rag, etc. to remove efflorescence, laitance, dust, dirt, etc., is transported on the feed roller 6 in the direction of arrow A. Then, an undercoat 7 (for example, "Mizeron R Primer" manufactured by Mitsui Kinzoku Paint Chemical Co., Ltd.) is supplied from between the coating rollers 8a and 8b rotating in the directions of arrows B and C, and is applied onto the concrete base material 1. This primer paint 7 is rubbed onto the surface of the concrete base material 1 by a reverse roller 9 rotating in the opposite direction to the direction of travel (in the direction of arrow D). As a result, the undercoat paint 7 penetrates into the minute irregularities on the surface of the concrete base material 1, forming an undercoat layer 2 with a relatively smooth surface (see FIG. 5a). After this undercoat layer 2 has hardened, the concrete base material 1 is then transferred to a coating layer smoothing device 11 shown in FIG.

This coating layer smoothing device 11 includes a drive roller 1
A conveyor belt 13 is provided, driven by a conveyor belt 2, on which the concrete substrate 1 is conveyed in the direction of the arrow E. For example, a rectangular frame 14 is arranged above the conveyor belt 12,
The above-mentioned plastic sheet 4 is stretched over this under tension. Further, above the frame 14, a rubber pressing roller 15 is arranged as a pressing body for pressing the plastic sheet 4 onto the concrete base material 1, and this pressing roller 15 moves in the direction of movement of the concrete base material 1. On the other hand, it is rotatable in the forward direction (direction of arrow F). Now, a concrete base material 1 is supplied here, in which a top coat is previously applied to the surface of the undercoat layer 2 after hardening to form an uncured paint film layer 16 as shown in FIG. 5b. In this case, the method of applying the top coat paint is as described above with the coating rollers 8a and 8.
This may be carried out using an automatic coating machine such as a roller coater equipped with rollers equivalent to b, a curtain flow coater, or a spray coater. Immediately after applying the paint, as shown in FIG.
The plastic sheet 4 is superimposed on the surface of the plastic sheet 4 without wrinkles, and in this state, the concrete base material 1 is sent together with the plastic sheet 4 by a conveyor belt 13 in the direction of arrow E. At this time, when the concrete base material 1 passes under the pressure roller 15 (rotation direction is in the direction of arrow F), the uncured coating layer 16 is pressed from above the plastic sheet 4 by the pressure roller 15. By this pressing action, the surface of the uncured coating layer 16 is sequentially smoothed along the lower surface of the plastic sheet 4, and the layer thickness is made to be 100 to 5000 μm. In this case, the surface of the plastic sheet 4 interposed between the uncured coating layer 16 and the pressure roller 15 has extremely high smoothness;
Since this surface is transferred to the surface of the uncured coating layer 16, the smoothness of the surface of the uncured coating layer 16 becomes extremely high. Then, by volatilizing the solvent in the uncured coating layer 16 through the fine pores of the plastic sheets 4 while the plastic sheets 4 are stacked in this manner, a cured top coating layer 3 can be obtained. Thereafter, the plastic sheet 4 is cut to match the dimensions of the concrete base material 1, so that it can be shipped as a product.

According to the present embodiment described above, since the surface of the coating layer 3 can be easily smoothed by the overlapping plastic sheet 4 when uncured, the surface of the undercoat layer 2 can be coated with putty as in the conventional method.・There is no need for polishing at all, saving you the trouble of repeatedly applying putty and polishing.
Manufacturing efficiency can be greatly improved and low-cost production becomes possible. Moreover, since the surface of the plastic sheet 4, which has extremely high smoothness, is transferred to the surface of the uncured coating layer 16 (coating layer 3) by the pressing action of the pressing roller 15, the surface of the uncured coating layer 16 ( The surface smoothness of the coating layer 3) was made extremely high, and in this example, the coating layer 3 was able to have an extremely high gloss level of 85 or higher at 60° specular reflection. Furthermore, the plastic sheet 4 overlaid on the coating layer 3 can be peeled off from the concrete base material 1 after the assembly of the concrete product is completed at the construction site, thereby making it easier to transport and transport the concrete product. Since the surface of the coating layer 3 can be protected by the plastic sheet 4 during construction, it is possible to prevent the surface of the coating layer 3, which has been formed with excellent smoothness, from being scratched as much as possible, thereby ensuring quality. This is extremely convenient. Furthermore, in this case, the plastic sheet 4 is not newly installed to protect the coating layer 3;
Originally, the material used to smooth the surface of the coating layer 3 is also skillfully used to protect the coating layer 3, so it does not increase the number of man-hours or the number of parts at all.
Extremely advantageous in terms of cost.

In addition, in the above embodiment, since the coating layer 3 is formed on the undercoat layer 2, the adhesive strength of the coating layer 3 is increased and peeling, cracking, etc. of the coating layer 3 can be 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 7 into the surface of the concrete base material 1, the unevenness on the surface of the concrete base material 1 is filled in with the undercoat 8 to smooth the surface of the undercoat layer 2. This can contribute to improving the smoothness of the surface of the coating layer 3, and further improve the adhesive strength of the undercoat layer 2 and ultimately the topcoat layer 3 to the concrete base material 1.

In the above embodiment, a so-called cola coater 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 other automatic coating machines such as a curtain flow coater or a spray coater may be used. It may be painted using.
In addition, even when rubbing the applied primer paint 7 onto the surface of the concrete base material 1, the reverse roller 9
For example, a rubber blade or brush may be brought into pressure contact with the surface of the undercoat layer 2 and rubbed. Further, in the above embodiment, an undercoat layer 2 is provided between the coating layer 3 and the surface of the concrete base material 1.
However, for example, the paint for the coating layer may be applied directly to the surface of the concrete base material 1, and if necessary, it may be rubbed in with a reverse roller, etc. In this case as well, the overlapping plastic sheets It goes without saying that the surface of the coating layer can be sufficiently smoothed by this method. Furthermore, the paint for the coating layer is not limited to a solvent-based paint, but may also be a solvent-free paint such as a two-component polyurethane paint. In this case, the plastic sheet does not need to have a fine porous structure in order to volatilize the solvent, so a sheet with excellent releasability such as general polypropylene, polyethylene or polyvinyl chloride can be used. Furthermore, in the first embodiment, the plastic sheet 4 is placed on the frame 14 from the viewpoint of preventing wrinkles from forming on the plastic sheet 4 which is superimposed on the surface of the uncured coating layer 17.
Although the plastic sheet is stretched under tension, 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 16.

In addition, the present invention can be modified in various ways without departing from the gist of the present invention, for example, a press mold may be used instead of the press roller 15 as the press body that presses from above the plastic sheet 4. be.

[Effects of the Invention] As is clear from the above description, the painted concrete product of the present invention has plastic sheets stacked on top of each other in an uncured state of the paint layer, so it is not possible to use putty as in the past. The surface of the coating layer can be made to be an excellent smooth surface based on the smoothness of the plastic sheet without repeating the coating and polishing process, thereby facilitating manufacturing and reducing costs. Moreover, the plastic sheet originally used to smooth the paint film layer can also be given the function of protecting the paint film layer after hardening, so the paint film can be removed during transportation and construction of painted concrete products. This has the remarkable effect of preventing the layer from being damaged and losing its long-awaited smoothness.

[Brief explanation of the drawing]

The drawing shows one embodiment of the present invention.
The figure is a partially enlarged sectional view of the concrete product, Figure 2 is a perspective view of the same, Figure 3 is a perspective view of the undercoat layer forming device,
FIG. 4 is a perspective view of the coating layer smoothing device, and FIG. 5 is a sectional view for sequentially explaining the manufacturing process of the coating layer. In the drawing, 1 is the concrete base material, 2 is the undercoat layer,
3 is a coating layer, 4 is a plastic sheet, 5 is an undercoat layer forming device, 12 is a coating layer smoothing device, 15 is a pressing roller (pressing body), and 16 is an uncured coating layer.

Claims (1)

[Scope of Claims] 1. A concrete base material, a paint film layer formed on the concrete base material, and the paint film formed by overlapping the paint film layer when uncured and pressing it with a pressing body. A painted concrete product comprising a peelable plastic sheet that smooths the layer and protects the paint layer after hardening. 2. The painted concrete product according to claim 1, wherein the coating layer has a thickness of 100 to 5000 μm. 3. The painted concrete product according to claim 1 or 2, wherein the coating layer is formed on an undercoat layer formed on the surface of a concrete base material.