JPS628787B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a covering for preventing pasting. Traditionally, advertising posters were often seen on utility poles, but due to changes in traffic conditions, road tracks have become three-dimensional, and as a result, the number of objects such as bridge piers, elevated walls, and underpass walls has increased, and advertising posters are now being posted everywhere. can be seen. These not only spoil the beauty of the surrounding area, but also require a lot of manpower and expense to remove them.
In order to prevent these stickers from appearing, rubber or resin plates having numerous protrusions are applied to telephone poles and the like, and silicone paint is applied to bridge piers and the like. However, since these are all made of organic substances, their surface durability and weather resistance are insufficient, and they cannot be expected to have a long-term sticker-preventing effect.
As another method, a coating composition for preventing pasting has been proposed in which aggregates such as glass beads and a lubricant are contained in a room temperature drying coating or a thermosetting coating (Japanese Patent Laid-Open No. 53-31739). . This method uses an uneven surface formed by glass beads, etc. instead of protrusions, but when such a paint composition is sprayed, the glass beads, etc. are partially buried in the paint film and become the main body. Since the paint is an organic paint such as polyurethane or alkyd, it is difficult to get acquainted with the glass beads and a sufficient effect may not always be obtained. The present inventors have conducted various studies on coatings for preventing stickers using glass beads, and as a result, have found that it is possible to prevent stickers extremely effectively by using glass beads with different particle sizes. As a result, the present invention has been completed. The present invention is a coating for preventing pasting, characterized in that at least two types of glass beads, large and small, are dispersed and adhered to a paint film applied to the surface of a base material. The paint used in the present invention is not particularly limited, and various organic or inorganic paints that are curable at room temperature or thermosetting can be used, but water glass-based inorganic paints that are curable at room temperature are advantageous. Such water glass-based paints have the general formula M ₂ OnSiO ₂ (M is Li, K, Na,
An inorganic curing agent is added to an aqueous solution of an alkali silicate or ammonium silicate represented by _NH4 , etc., where n is 0.5 to 10, and aggregates, fillers, etc. are appropriately blended. Preferred hardening agents include calcium sulfite, calcium thiosulfate and calcium silicate, to which zinc oxide, aluminum hydroxide, alumina, hydrated alumina, etc. may be added. Calcium carbonate, silica sand, perlite is generally used as the aggregate, and talc is generally used as the filler. The paint thus formulated is preferably applied on the substrate from about 1 to 3 kg/m ²
applied by spraying or other methods. The feature of the present invention is to disperse and adhere at least two types of particles with different particle sizes as glass beads, and the preferable range is that the particle size of the large glass beads (hereinafter referred to as large beads) is 800 to 2500 μm, More preferably, the particle size is 800 to 1200μ, and the particle size of small beads (hereinafter referred to as small beads) is 10 to 150μ, and more preferably 10 to 100μ. If the particle size is other than the above, the sticker prevention effect of the present invention, which will be described later, will not be sufficient. Such glass beads are dispersed and adhered by a method such as spraying while the coating film applied to the substrate is not sufficiently dried and cured. The glass beads sprayed with appropriate pressure are not completely submerged in the paint, but their surfaces are exposed.
Regarding the state of adhesion of the glass beads to the paint surface, it is preferable that about 40 to 60% of the particle size is exposed. In addition, in the case of water glass paint, finishing is done twice by under-spraying and top-spraying, but after kneading a predetermined amount of beads into the top-spraying paint and spraying it, the glass beads are removed by polishing the surface after the paint has hardened. It can also be exposed. In carrying out the present invention, in order to uniformly disperse and adhere glass beads of different particle sizes onto the coating surface, it is necessary to mix the large beads and small beads well with each other before spraying. If one of the glass beads is sprayed first, or if the glass beads are sprayed without mixing well, the glass beads adhering to one end will interfere with the adhesion of the glass beads to be sprayed later, and the large beads and small beads will not be able to interact with each other. It is not possible to obtain a well-dispersed coating surface. Further, one type each of large beads and small beads may be used, but there is no problem in using multiple types of each type within the above particle size range. The effect of preventing stickers according to the present invention will be explained with reference to the drawings. As shown in FIG. Since the beads 3 form almost the same plane, they are completely glued together. Now the second
As shown in the figure, when large beads 5 and small beads 6 are dispersed and attached, a large number of small beads 6 are placed in the gaps between the groups of 5 large beads.
Since the group is dispersed and forms an uneven surface, the sticker 4 is adhered only to the large beads 5 and hardly adhered to the small beads 6. Therefore, compared to FIG. 1, the adhesive area between the glass beads and the sticker is extremely small for the same area of the painted surface. Furthermore, even if a large amount of glue is used to adhere the paper, or if the whole is pressed firmly by hand, the adhesive force in that area will be extremely weakened because the small beads are dispersed between the large beads. According to experiments by the inventors, large beads 100
Small beads 20-100 parts by weight, especially 20-70 parts by weight
The ratio of parts by weight gives the best results. Further, in order to enhance the sticker prevention effect of the present invention, a silicone water repellent may be applied to the surface to which the glass beads are attached. This water repellent may be either water-based or oil-based such as methyl silicone or acrylic modified silicon, but in the case of outdoor painting, oil-based water repellents are preferred. As described above, in the coated body of the present invention, beads with a small particle size are dispersed in the gaps between beads with a large particle size, so glass beads with a substantially uniform particle size are dispersed even though there is some difference in particle size as in the conventional case. The effective area for pasting paper is reduced compared to a covered body made of paper, which not only makes it difficult to paste, but also makes it extremely easy to peel off once pasted. In addition, because the glass beads have different particle sizes, the reflection of light is complex, creating a unique and beautiful appearance. In particular, when using water glass-based paints that harden at room temperature, they have a much better adhesion to glass beads than inorganic paints such as cement or organic paints, and even if exposed outdoors for long periods of time, the paints will not be exposed to ultraviolet rays, ozone, etc. There is no oxidative deterioration of the glass beads, and the glass beads do not come off. In addition, since it cures at room temperature, it is advantageous for coating buildings with large surface areas where heat curing is inconvenient, and is particularly suitable for coating lower bridge walls, pedestals, and underground passage walls where there are many pasted papers. In the Examples and Comparative Examples shown below, the compositions are all based on weight. Examples and Comparative Examples 56 parts of calcium carbonate, 7 parts of calcium sulfite, 2 parts of calcium silicate, 1 part of aluminum hydroxide, and 6 parts of inorganic pigments were added to 28 parts of aqueous sodium silicate solution (solid content 34%) to obtain a uniform composition. Stir well until. The obtained room-temperature curable paint composition was sprayed onto a 3 mm thick asbestos board with a spray gun to a coating thickness of about 1 mm, and while the paint was still wet, 100 parts of glass beads having the particle size shown in Table 1 was applied to the paint. It was sprayed uniformly on the surface to prepare a test plate. The oil-based silicone water repellent was applied after being cured for 24 hours after spraying the glass beads. Approximately a certain amount of starch glue was applied to the test board obtained in this way, and paper 5 cm wide and 15 cm long was pasted on it.
After curing for 120 hours, a clockwork scale with a scale as shown in FIG. 3 was placed at the tip of the paper 4, and the force with which the paper 4 was peeled off at the same speed was measured to determine the degree of difficulty in peeling. The results are shown in Table 1. 【table】

[Brief explanation of the drawing]

Figures 1 and 2 are schematic cross-sectional views for explaining a conventional product and a product of the present invention in which glass beads are dispersed and adhered to the coating layer, respectively, and Figure 3 is a diagram illustrating a method for testing the peeling of paper stickers for the product of the present invention. FIG. 1...Substrate, 2...Coating layer, 3, 5, 6...Glass beads, 4...Paper, 7...Spring scale with scale.

Claims (1)

[Scope of Claims] 1. A coating for preventing pasting, characterized in that at least two types of glass beads, large and small, are dispersed and adhered to a paint film applied to the surface of a base material. 2 The particle size of the large seed glass beads is 800μ or more, and the particle size of the small seed glass beads is 150μ.
A covering for preventing pasting according to claim 1, which is as follows. 3. The coating for preventing pasting according to claim 1 or 2, wherein the amount of small seed glass beads is 20 to 100 parts by weight per 100 parts by weight of large seed glass beads. 4. The coating for preventing pasting according to any one of claims 1 to 3, wherein the paint is a water glass-based inorganic paint that cures at room temperature.