JP2001123122A - Coating material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new coating material composition capable of raising mechanical strength of coating film, preventing crack and release of coating film and not accumulating a fibrous material even in the case of scattering of fibrous material in the air in release of a coating film or in the dismantlement operation of building by compounding a coating material composition with a fibrous substance. SOLUTION: This composite material composition is obtained by compounding a coating material with a gypsum fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition applied to an outer wall of a building or the like.

[0002]

2. Description of the Related Art In order to protect the outer wall of a building from the weather and to decorate the surface of the outer wall, it is common practice to paint the outer wall of the building. Paints used outdoors are required to have weather resistance under severe weather conditions that are exposed to wind, rain, or light from the sun. In particular, since the coating film repeatedly expands and contracts due to differences in temperature, attempts have been made to add various fibers to the coating material as a reinforcing material for the purpose of increasing the mechanical strength of the coating film so that the coating does not crack. I have. For example, Japanese Patent Application Laid-Open No. 57-145164 proposes a base coating composition comprising an asphalt emulsion, a synthetic resin emulsion and alkali-resistant glass fiber, and Japanese Patent Application Laid-Open No. 60-137972 discloses an undercoat composition. Paints incorporating synthetic fibers are disclosed.

[0003] However, when a paint containing a fibrous substance is used, when the paint film is peeled off with the passage of time or when dismantling a building or the like, the paint film becomes dusty and the fibers contained in the paint film become airborne. There is a problem that it may be scattered inside, which is not preferable from the viewpoint of environmental conservation.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a fibrous substance is added to a coating composition to increase the mechanical strength of a coating film, to prevent cracking and peeling of the coating film, and to remove the coating film. An object of the present invention is to provide a novel coating composition in which fibrous substances do not accumulate in the natural environment even when fibrous substances are scattered into the atmosphere during the demolition work of a building.

[0005]

In view of such circumstances, the present inventor has conducted intensive tests and studies, and as a result, it has been possible to prevent cracking or peeling of the coating film by adding gypsum fiber to the coating material. And, even when the coating film was dusted during the peeling or dismantling work of the coating film, it was found that the exposed gypsum fibers became non-fibrous by reacting with water in the natural environment, and the present invention was completed. .

[0006] The paint used in the practice of the present invention is:
Although not particularly limited, paints such as asphalt-based, urethane-based, acrylic-based, styrene-butadiene-based, vinyl acetate-based, vinyl chloride-based, vinylidene chloride-based, and alkyd-based paints can be used. .

[0007] The method for producing gypsum fiber used in the practice of the present invention is not particularly limited, but is disclosed in Japanese Patent Application No. Hei 11-113, filed on Nov. 10, 1997.
The water-repellent hemihydrate gypsum fibers synthesized by the method described in 230938 have a higher aspect ratio than conventionally known gypsum fibers,
In addition, because of good compatibility with the resin, when blended into a paint, the mechanical strength of the paint film can be dramatically increased, and as a result, cracks in the paint film are less likely to occur, and peeling of the paint film can be prevented. There is a feature that can be suppressed.

Although the shape of the hemihydrate gypsum fiber is not particularly limited, a diameter of 2 μm
Below, it is preferable that the thickness is 1 μm or less and the aspect ratio is 20 or more, preferably 40 or more. Further, the surface of the fiber may be appropriately modified using various treatment agents.

In the practice of the present invention, the content of hemihydrate gypsum fiber to be incorporated into the paint should be in the range of 1 to 20% by volume, and when the content of the gypsum fiber is less than 1% by volume, However, a sufficient effect of reinforcing the coating film does not appear, and if it is more than 20% by volume, the fluidity of the coating material is reduced, and the workability of the coating material production and coating is remarkably deteriorated.

[0010] In the practice of the present invention, the method of compounding the gypsum fiber and the paint or the method of application is not particularly limited. Also, within a range that does not impair the effects of the present invention,
Various additives, treating agents, pigments or inorganic particles may be added.

The coating composition thus obtained is not limited to the outer wall of a house, but also includes the roof, floor, and inner wall of a building.
It can be widely applied to anticorrosion coating applied to bridges, piping installed outdoors, and mechanical equipment.

[0012]

In order to prevent cracking or peeling of the coating film, it is effective to add a fibrous filler as a reinforcing material to the paint. This is because the fibrous substance mixed in the paint
This is because they are dimensionally entangled and directly act on a tensile force such as cracking or peeling, and also play a role of relaxing thermal stress. Since fibrous fillers used in such applications are required to be chemically stable substances that do not react with paints or paint additives, composites such as paints containing fibrous fillers are required. In the case of dusting, the filler is released into the air in a fibrous state. If gypsum fibers are combined with a resin, such as paint, and placed in conditions that do not directly contact water, the gypsum fibers are chemically stable for a long period of time. In addition, when it is released into the atmosphere, it changes from anhydrous gypsum or hemihydrate gypsum to dihydrate gypsum when it comes in contact with water such as rain. Does not remain in a fibrous state for a long time. In particular, the gypsum fiber synthesized by the method described in Japanese Patent Application No. 11-230938 has a water-repellent substance uniformly adsorbed on the fiber surface during the fiber synthesis stage, and the gypsum fiber is not compatible with the resin of the paint. Since it becomes better, it is more effective in preventing cracking and peeling.

[0013]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. The raw materials and evaluation test methods used in the examples and comparative examples are as shown below. [Resin] Resin 1: Asphalt-based emulsion Resin 2: Urethane-based emulsion Resin 3: acrylic-based emulsion [Fiber] Gypsum fiber 1: A fiber synthesized by the following method was used. Gypsum dihydrate was dispersed in water to form a 6% slurry, which was kept in an autoclave at 120 ° C./2 hours. The treated slurry is subjected to solid-liquid separation, dried at 80 ° C., and is 2 μm in diameter and 50 μm in length.
m of hemihydrate gypsum fiber was prepared. Gypsum fiber 2: A fiber synthesized by the following method was used. 2
Paraffin was added to the mol / l calcium chloride aqueous solution so as to be 3 g / l, and a 0.5 mol / l sodium sulfate aqueous solution four times the amount of the calcium chloride aqueous solution was boiled for 5 seconds each. It was dripped in about. The obtained slurry was separated into solid and liquid and dried at 80 ° C.
Gypsum hemihydrate gypsum fibers having a length of 50 μm were prepared. Gypsum fiber 3: A fiber synthesized by the following method was used. 1
Magnesium stearate was added to a 1.5 mol / l aqueous solution of calcium chloride at a concentration of 1.5 g / l, and a 0.5 mol / l aqueous sodium sulfate solution twice as much as the calcium chloride aqueous solution was boiled. After that, it was dropped in about 5 minutes. The obtained slurry is subjected to solid-liquid separation,
To prepare a hemihydrate gypsum fiber having a diameter of 1 μm and a length of 100 μm. [Evaluation Test] An evaluation sample was set on a cooling / heating cycle tester (Kusumoto Kasei, LRH-E-1R type), and was heated at 70 ° C. for 10 minutes / cooling for 10 minutes / minus 10 ° C. for 10 minutes / heating for 10 minutes (1 Under the set conditions of (cycle 40 minutes), the number of cycles until the coating film of the test piece cracked was measured.

[Examples 1 to 6, Comparative Examples 1 to 3] A coating composition was prepared by blending the above raw materials at the ratios shown in Table 1.
It was applied to a 30 cm square gypsum board prepared in advance to a thickness of 2 mm. The obtained test piece was set in a thermal cycle tester, and the number of cycles until cracks were formed in the coating film was measured. The test results obtained were as shown in Table 1.

[0015]

[Table 1]

According to the test results in Table 1, the coating film prepared using the paint containing gypsum fiber is less likely to crack and has excellent durability over a long period of time, as compared with the case where no fiber is added. Is considered to be able to demonstrate.

[0017]

The coating composition comprising the gypsum fiber of the present invention has excellent durability against cracking and spalling of the coating film, and is applied when the coating film is peeled off or the work is dismantled. Even when the gypsum fibers in the film are exposed and scattered in the atmosphere, the gypsum fibers react with water and become non-fibrous, so that they have a great effect on use, such as being safe to handle environmentally.

Claims (2)

[Claims] 1. A coating composition comprising gypsum fibers blended in a coating. 2. The coating composition according to claim 1, wherein the gypsum fiber is a hemihydrate gypsum fiber in which a substance capable of imparting water repellency during synthesis is adsorbed on the fiber surface.