JPH116242A - Painted alc panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent separation of a coating film on the surface of a panel and ensure durability by specifying tensile strength after hardening of water undercoating material applied to a top coat layer having distortion due to hardening shrinkage of a fixed value or more. SOLUTION: After a water under coating material layer 3 having the tensile strength after hardening of 10 kgf/cm<2> or more is formed on the surface, a top coat layer 2 having distorsion due to hardening shrinkage of 1×10<-4> or more is formed. The water under coating material layer 3 has water permeability of 0.2 cm<2> or less measured by a water permeability test A method regulated in JIS-A-6909 revised in 1995. Subsequently, water sealer layer 4 is formed between the surface of ALC panel 1 and the water under coating material layer 3. Further, as a top coat layer 2, organopolysiloxane inorganic painting material is painted to form a primer layer 5 is formed between the water under coating material layer 3 and the polysiloxane inorganic painting material layer. Thus, good wear-resistance, weather-proofness, water resistance and acid resistance can be obtained, so that cracks in the top coat layer 2 and separation of a coating film and the panel surface layer can be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a painted ALC panel used for an outer wall panel and the like, and more particularly, to a painted ALC panel having excellent weather resistance and durability, and in particular, having little peeling and cracking of its coating film. It is about.

[0002]

2. Description of the Related Art Lightweight cellular concrete panels (hereinafter referred to as A)
A porous substrate such as an LC panel) has a fragile surface and easily absorbs water, so that it has abrasion resistance, weather resistance, water resistance,
Various paints are applied to impart acid resistance and the like.
Acrylic resin-based paints, epoxy resin-based paints, and organopolysiloxane-based inorganic paints are often used as the main types of paints. Among them, organopolysiloxanes are particularly preferred for imparting excellent weather resistance and durability. A siloxane-based inorganic paint is preferably used.

[0003] When these paints are applied, an undercoat material (filler) is applied to the surface of the panel in advance to reduce the unevenness. As a typical example of a panel in which the undercoat material layer and the top coat layer made of an inorganic paint are formed, a coating structure disclosed in Japanese Patent Application Laid-Open No. 6-279151 has been proposed.

[0004]

However, Japanese Patent Application Laid-Open No.
The coating structure disclosed in Japanese Patent No. 279151 is also excellent in weather resistance, heat resistance, water resistance, acid resistance, and the like. However, since the coating film of the inorganic coating has low elasticity, cracks are formed in the coating film of the top coat layer. There was a problem. As a result, the coating film easily peels off from the panel surface, and the ALC panel has a special characteristic that its surface tensile strength is quite small unlike concrete, etc. was there. In addition, these problems often occur in other paints, for example, epoxy-based reaction-curable resins.

The inventor of the present invention has conducted various investigations on the causes of these cracks in order to eliminate cracks in the top coat layer of the ALC panel and peeling of the coating film and the panel surface layer.
The main factor was distortion due to curing shrinkage of these top coat layers, and it was found that the distortion was particularly remarkable when the value was 1 × 10 ⁻⁴ or more. Therefore, as a result of further study, it was determined that the above problems could be solved by setting the tensile strength after curing of the undercoat material layer to the top coat layer to a specific value or more, and reached the present invention.

[0006]

That is, in order to solve these problems, the present invention provides an ALC panel in which a water-based undercoating material layer having a tensile strength after curing of 10 kgf / cm ² or more is formed. And a coated ALC panel on which a top coat layer having a distortion due to curing shrinkage of 1 × 10 ⁻⁴ or more was formed.

In the present invention, the strain due to curing shrinkage is 1 ×.
Tensile strength after curing of the water-based undercoating material applied as a base adjustment to ^10-4 or more topcoat layers is 10 kgf /
When it is not less than cm ² , it becomes possible to withstand the curing shrinkage of the top coat layer even if the aqueous undercoat material is pulled.

When a top coat layer is formed on the surface of the panel, if an undercoat material (for example, a resin-containing cement paint) having a tensile strength after curing of less than 10 kgf / cm ² is used, the top coat layer becomes In many cases, the coating film is peeled off from the undercoat material due to the distortion due to the curing shrinkage.
Therefore, it is necessary that a water-based undercoat material layer having a tensile strength after curing of 10 kgf / cm ² or more is formed below the top coat layer. It is preferable that a water-based undercoat material having a tensile strength after curing of 30 kgf / cm ² or less is applied. That is, even if the tensile strength after curing exceeds 30 kgf / cm ² , the effect is saturated, and such a water-based undercoating material is a special material having no versatility, so that it is expensive.

As a water-based undercoat material having a tensile strength after curing of 10 kgf / cm ² or more, an epoxy resin emulsion paint is suitable, but other paints may be used. Further, to a paint having a low tensile strength, a reinforcing agent of an epoxy emulsion or a rock wool fiber, a natural fiber, a glass fiber, or a cellulose fiber of 1 mm or less is added so that the cured tensile strength is 10 kgf / cm ² or more. May be used

The coating amount is preferably in the range of 1.0 to 3.3 kg / m ² , and more preferably 1.2 to 2.3 kg / m ² .
It is in the range of 5 kg / m ² . The application method includes a method using a roller and a method using a spray. The application amount of the top coat layer is in the range of 0.03 to 5.0 kg / m ² . The application method is also typically a method using a roller or a method using a spray.

Further, in the present invention, the water-based undercoat material layer is a paint having a water permeability such that a test result by a water permeability test A method specified in JIS A 6909 (revised in 1995) is 2.0 cm or less. It is desirable. If the water permeability of the paint exceeds 2.0 cm, if water enters through pinholes, fine cracks, etc. in the top coat layer, the undercoat material layer absorbs the water, and the surface tensile strength of the water-based undercoat material layer decreases significantly. As a result, the strength of the undercoat material decreases, and the coating film peels off from the undercoat material. Therefore, when the coating material is used particularly in a region with a large amount of rainfall or a place where water is bathed, the above-described coating material is preferable. For this purpose, a coating material having a low water permeability, to which a water-repellent material is added, may be used.

Next, it is desirable that an aqueous sealer layer is formed between the surface of the ALC panel and the aqueous undercoat material layer. In other words, the water-based sealer layer has the effects of preventing the undercoat material from being sucked into the panel, preventing precipitation of alkali components in the panel, improving corrosion resistance, improving adhesion, and controlling the water absorption and surface tensile strength of the ALC panel surface. Those that improve are preferred. Note that the sealer layer is preferably an aqueous type such as a styrene / acrylic resin emulsion, an acrylic resin emulsion, acrylic, an epoxy resin composite emulsion, or an epoxy resin emulsion. The appropriate amount of coating is 0.2 to 0.4 kg / m ² .

In the present invention, when the top coat layer is made of an organopolysiloxane-based inorganic coating, particularly excellent weather resistance and durability are imparted, so that more remarkable effects can be obtained. However, distortion due to curing shrinkage is 1 × 10 ^−4.
Since the above organopolysiloxane-based inorganic paint is a hard material, the strain of the strain caused by curing shrinkage affects the water-based undercoating material and is extremely damaged.
It is even more important to increase the tensile strength of the water-based primer.

In a coated ALC panel coated with an organopolysiloxane-based inorganic paint as a top coat layer, a panel in which a primer layer is formed between a water-based undercoat material layer and the organopolysiloxane-based inorganic paint layer. Then even better. As the primer layer, various types of conventionally known primer coatings for inorganic decorative boards can be used. In particular, primers such as acrylic emulsion resin-based, epoxy emulsion resin-based, and hydrolyzable silyl group-containing acrylic resin-based primers are water-based primers. In addition to improving the adhesion between both the coating film of the organopolysiloxane-based inorganic paint and the coating film, the coating film is further densified, and has the effect of making it difficult to cause delamination between the water-based undercoat material layer and the top coat layer. This has the effect of increasing the adhesion between the two.

[0015] The coated ALC panel of the present invention is completed by first applying the water-based primer to the surface of the panel and then coating the topcoat layer thereon. When a design is added, it is desirable to apply the water-based primer twice. By applying the water-based undercoat material twice, it is possible to obtain a painted panel having a higher design property, and it is possible to make the painted panel more reliably exhibit water resistance and acid resistance. The coating amount is preferably in the range of 0.6 to 1.5 kg / m ² for the first time and in the range of 0.4 to 1.8 kg / m ² for the second time.

Further, when an organopolysiloxane-based inorganic paint is used for the top coat layer, it is desirable to perform IR drying (infrared drying) of the applied top coat layer. In order to dry an organopolysiloxane-based inorganic paint in a short time, it is necessary to dry it at a high temperature of about 120 ° C. Although damage is caused, in IR drying, only the painted surface can be dried, so that the paint can be dried without damaging the panel. However, if a long time is not required for drying the paint, it may be left to natural drying.

The ALC panel conforms to JIS A 54
16 (revised in 1995) is often used as a wall of a building.
Panels with specially high strength, those with sound absorption, those with humidity control, etc. are also used.
It is not limited to the specified ALC panel.

[0018]

[Comparative Example]

Example 1 As shown in FIG. 1, an aqueous sealer (Durox sealer, manufactured by Toyo Chemicals Co., Ltd.) of an emulsion containing styrene / acrylic as a main component was applied on the painted surface of the ALC panel 1 at 0.3 kg / m ^2. After coating to form a water-based sealer layer 4, a water-repellent material (X-5 manufactured by Shin-Etsu Chemical Co., Ltd.)
2-517) -added epoxy resin-based emulsion paint (Dainippon Paint Co., Ltd. product: ALC filler) was added in an amount of 0.9.
The aqueous undercoating material layer 3 was formed by applying kg / m ^2, and dried by IR at an ambient temperature of 60 ° C. for 60 minutes. This epoxy resin-based emulsion paint (Dainippon Paint Co., Ltd. product: ALC filler) was tested by a water permeability test A method specified in JIS A 6909 (revised in 1995).

The same material as that of the water-based undercoat material layer 3 was again used as an intermediate coating material, which is a part of the water-based undercoat material layer 3, at 0.6 kg / m 2.
^{2 was} applied and IR-dried at an ambient temperature of 60 ° C. for 60 minutes.
The surface tensile strength of the paint was measured for a part of the panel to which the water-based undercoat material layer 3 was applied as described above. Further, the panel was immersed in water at room temperature for 2 days, and the surface tensile strength of the subsequent paint was measured.

For the remaining panel, a primer of an acrylic resin containing a hydrolyzable silyl group, which is an organic / inorganic composite component, was applied at a rate of 0.05 kg / m ² to form a primer layer 5 on the aqueous undercoat material layer 3. Is formed at an ambient temperature of 120.
Dry at IR for 7 minutes. Inorganic paint (product of Nippon Synthetic Rubber Co., Ltd.) as a colorant in the top coat layer 2
The main material Glasca E1102) was applied so as to have a film pressure of 10 μm, and was IR-dried at 120 ° C. for 10 minutes.
Similarly, a clear inorganic paint (manufactured by Nippon Synthetic Rubber Co., Ltd .: Glasca T2102) is applied as a gloss imparting material in the top coat layer 2 so as to have a film pressure of 5 μm to form the top coat layer 2. Finished by IR drying at 120 ° C. for 10 minutes.

After the painted panel thus finished is left for 7 days, it is subjected to a repeated heating / cooling test specified in JIS A 6909 (revised in 1995).
The state of cracks in the coating film was visually observed. Table 1 shows test results obtained by the water permeability test method A, measurement results of surface tensile strength before and after immersion in water, and observation results of the crack state of the coating film of the coated panel.

Example 2 In the same manner as in Example 1, after forming a water-based sealer layer 4 of an emulsion containing styrene / acryl as a main component on the coating surface of the panel 1, a water-repellent material was used as a water-based undercoat material layer 3. An epoxy resin-based emulsion paint (Dai Nippon Paint Co., Ltd. product: ALC filler) to which no addition was made was formed in the same manner as in Example 1, and drying was repeated, and the primer layer 5 and the top coat layer 2 were the same as in Example 1. It was formed and dried in the same manner, and the same test as in Example 1 was performed. Also in Example 2, the test results of the water permeability test A method of the epoxy resin emulsion paint without adding the water repellent material, the measurement results of the surface tensile strength of the water-based undercoat material layer before and after immersion in water, and the coating of the coated ALC panel Table 1 shows the observation results of the crack state of the film.

COMPARATIVE EXAMPLE After forming an aqueous sealer layer on the painted surface of the panel in the same manner as in Examples 1 and 2,
Instead of the epoxy resin-based emulsion paint, a resin-added cement-based paint (manufactured by Onoda Co., Ltd.) as a comparative example:
Example 1 Water-based Undercoat Material Layer Using Super Filler)
And a primer layer and a top coat layer were formed in the same manner as in Examples 1 and 2, and the same tests as in Examples 1 and 2 were performed.
Table 1 shows the results.

[0024]

[Table 1]

As is clear from Table 1, Examples 1 and 2 have a surface tensile strength of 10 kgf / cm ² or more before immersion in water (that is, a normal state). Cracks were not generated or were slight.
On the other hand, in the comparative example, since the surface tensile strength before immersion in water was less than 10 kgf / cm ² , cracks occurred after the repeated hot and cold test. Further, since the test result of the water permeability of Example 1 is less than 2.0 cm, the surface tensile strength after immersion in water is 10 kgf / cm ² or more. This indicates that even after the top coat layer was formed in this state and the test was repeated with heating and cooling, no cracks were generated or the cracks were slight.

[0026]

The coated ALC panel of the present invention has excellent abrasion resistance, weather resistance, water resistance, acid resistance, etc., and cracks in the top coat layer.
The peeling of the coating film from the undercoat material and the peeling of the panel surface layer are small. Accordingly, since the panel has excellent durability, it is an extremely suitable panel for use as an outer wall panel or the like.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of a coated ALC panel of the present invention.

[Explanation of symbols]

 Reference Signs List 1 ALC panel 2 Top coat layer 3 Water-based undercoat material layer 4 Water-based sealer layer 5 Primer layer

Claims (5)

[Claims] An aqueous undercoating material layer having a tensile strength after curing of 10 kgf / cm ² or more is formed on the surface of an ALC panel, and a strain due to curing shrinkage of 1 × 10 ^-4 is formed thereon.
A coated ALC panel comprising the above-mentioned top coat layer. 2. The water-based undercoating material layer is made of JIS A69.
The coated ALC panel according to claim 1, which is a paint having a water permeability such that a test result obtained by a water permeability test A method specified in S.09 (1995) is 2.0 cm or less. 3. The coated ALC panel according to claim 1, wherein an aqueous sealer layer is formed between the surface of the ALC panel and the aqueous undercoat material layer. 4. The coated ALC panel according to claim 1, wherein said top coat layer is made of an organopolysiloxane-based inorganic paint. 5. The coating A according to claim 4, wherein a primer layer is formed between said water-based undercoat material layer and a top coat layer made of said organopolysiloxane-based inorganic paint.
LC panel.