JPH11279488A - Heat-resistant coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-resistant coating composition suitable for coatings used for various kinds of metal structures, installations, piping or devices exposed to severe environments, such as a raining environment, during operations at high temperatures, and especially having both excellent crack-peeling resistance and excellent corrosion resistance without depending to the thickness of a coating film. SOLUTION: This heat-resistant coating composition comprises 20-60 wt.% of a silicone resin, 1-25 wt.% of glass powder having an average particle diameter of <=100 μm, 0.3-25 wt.% of glass fibers having a fiber length of 100-3,000 μm and a fiber diameter of 1-50 μm, 0.1-10 wt.% of an anticorrosive pigment, 1-30 wt.% of another pigment and 20-60 wt.% of a solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition, and more particularly to a coating composition for various metal structures, facilities, pipes and devices which are exposed to a severe environment such as rainwater during operation at a high temperature. The present invention relates to a heat-resistant paint composition suitable for paint.

[0002]

2. Description of the Related Art A paint applied to a structure that is exposed to rainwater or the like during operation in a severe environment, particularly at a high temperature, is problematic in that the corrosion of a formed paint layer, generation of cracks or peeling in such an environment. Become.

As the conventional heat-resistant paints, there have been proposed those using rust-preventive pigments having excellent corrosion resistance as pigments and those using resin binders having excellent heat resistance.

Further, there has been proposed a method of applying a plurality of paint layers having specific functions in a superposed manner. For example, as described in JP-A-56-40543, a rust preventive pigment is applied to the surface to be coated. A method has also been proposed in which both abrasion resistance and corrosion resistance are improved by forming a baked layer of a primer-containing primer and coating the surface with a paint containing glass fiber.

[0005] However, the conventional heat-resistant paint is not always satisfactory for use under severe outdoor conditions. However, there is a problem that crack generation, peeling and corrosion progress. To solve this problem, the thickness of the coating film must be increased,
As described in US Pat. No. -40543, a method in which a plurality of paint layers are applied in a layered manner is effective. However, when a conventional paint is used, a thicker film is applied in reverse in terms of cracking and peeling. There is a problem of deteriorating the film performance, and further, it is disadvantageous to apply a coating layer having a plurality of functions separately, in addition to the production cost of the paint itself, as well as to increase the application cost.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is made of various kinds of metal which are exposed to a harsh environment such as rainwater during operation at a high temperature. An object of the present invention is to provide a heat-resistant paint composition suitable for paints for structures, equipment, piping and equipment, and particularly to crack resistance, peeling resistance and corrosion resistance without depending on the film thickness of the coating film. It is an object of the present invention to provide an excellent heat-resistant coating composition.

[0007]

In order to solve the above-mentioned problems of the prior art, according to the present invention, a heat-resistant coating composition is provided.
20-60% by weight of silicone resin, average particle size 100μm
The following glass powder 1 to 25% by weight, fiber length 100 to 30
00 μm, glass fiber with fiber diameter of 1 to 50 μm 0.3 to 2
It is characterized by comprising 5% by weight, 0.1 to 10% by weight of an anticorrosive pigment, 1 to 30% by weight of another pigment, and 20 to 60% by weight of a solvent.

As described above, the coating composition of the present invention contains a combination of a glass powder and a glass fiber in addition to a specific resin and an anticorrosive pigment. It is possible to obtain a paint layer in which both the crack / peeling resistance and the corrosion resistance are dramatically improved.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-resistant coating composition according to the present invention comprises
20-60% by weight of silicone resin, average particle size 100μm
The following glass powder 1 to 25% by weight, fiber length 100 to 30
00 μm, glass fiber with fiber diameter of 1 to 50 μm 0.3 to 2
5% by weight, 0.1 to 10% by weight of an anticorrosive pigment, 1 to 30% by weight of another pigment, and 20 to 60% by weight of a solvent.

In the present invention, the silicone resin is not particularly limited, but is selected from phenylmethyl-based straight silicone resin, alkyd-modified, polyester-modified, epoxy-modified and urethane-modified in terms of improving coating properties. A modified silicone resin or a mixture comprising a combination of these resins can be preferably used. Among these resins, a resin having excellent flexibility can be particularly preferably selected.

The compounding amount of the silicone resin component is 20 to 6
0% by weight, and more preferably 30 to 50% by weight. If it is less than 20% by weight, the coating film becomes brittle and disadvantageous in terms of heat resistance. On the other hand, if it is added in excess of 60% by weight, the drying of the coating film will be slowed down, and the coating film will not be sticky or stained for a long time, which is not practical.

As the pigment, an anticorrosion pigment having corrosion resistance or the like is used, and the kind of the pigment is not particularly limited.
As anticorrosive pigments, zinc phosphate, aluminum phosphate,
Pollution-free pigments such as calcium phosphate, magnesium phosphate, zinc molybdate, and calcium molybdate are preferably used. The compounding amount of the anticorrosion pigment is preferably from 0.1 to 10% by weight, more preferably from 0.5 to 7% by weight. If the amount of the pigment is less than 0.1% by weight, the effect of the addition is poor. On the other hand, if the amount exceeds 10% by weight, the effect is saturated and the cost is disadvantageous.

As other pigments, scaly pigments are particularly preferably used in addition to ordinary extender pigments. The extender can be appropriately selected from talc, kaolin, clay, precipitated barium sulfate, calcium carbonate, etc., in combination of one or more types in consideration of heat resistance. The flaky pigment can be appropriately selected from a combination of one or more of glass flake, mica, flaky iron oxide, and flaky aluminum powder.

The content of other pigments is 1 to 30% by weight.
And more preferably 2 to 25% by weight. If the amount of the pigment is less than 1, the cost is disadvantageous.
If it is added in excess of% by weight, it becomes difficult to mix other raw materials, which is not practical.

In the present invention, glass powder and glass fiber are contained in combination.

That is, in the present invention, the average particle diameter is 1
The glass powder is blended in an amount of 1 to 25% by weight, preferably 3 to 15% by weight, of a glass powder having an average particle diameter of 50 μm or less, preferably 00 μm or less. If the average particle size of the glass powder exceeds 100 μm, the dispersibility and workability become extremely poor, and the smoothness of the coating film is undesirably reduced. If the glass powder content is less than 1% by weight, cracks and peeling of the coating film still tend to occur, while if it exceeds 25% by weight, the peeling phenomenon is liable to occur, and the film is required as a paint. It is not preferable because problems such as difficulty in blending other pigments or the like occur. As the glass powder, a glass powder having a uniform particle size, which is usually obtained by pulverizing plate-like glass using, for example, a ball mill or the like, can be preferably used.

Further, in the present invention, in addition to the above glass powder, a fiber length of 100 to 3000 μm, preferably 2 μm
Glass fibers having a diameter of 00 to 1000 μm and a fiber diameter of 1 to 50 μm, preferably 1 to 20 μm are mixed in an amount of 0.3 to 25% by weight, preferably 0.5 to 15% by weight. As the fiber length increases, the heat resistance tends to be improved with a smaller blending amount. On the other hand, when the fiber length increases, the dispersibility decreases. If the glass fiber content is less than 0.3% by weight, cracks and peeling are likely to occur. On the other hand, if it is more than 25% by weight, the pigment dispersibility is greatly reduced, which is a necessary component for the paint. It is not preferable because problems such as difficulty in blending other pigments or the like occur.

As the solvent, a solvent conventionally used for heat-resistant paints can be appropriately used, and is not particularly limited. Preferred solvents include toluene, xylene,
Ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, ethanol, isopropanol and the like can be used. The compounding amount of the solvent is 20 to 60% by weight, preferably 30 to 50% by weight.

Further, in the present invention, in addition to the above-mentioned components, additives such as a plasticizer, a pigment dispersant, a thickener and the like which are usually used in paints can be appropriately added as needed.

In preparing the paint, the above-mentioned components are mixed using a high-speed disperser, a sand mill, a ball mill or the like.
The heat-resistant coating composition of the present invention can be obtained by stirring and mixing in a temperature range of 5 to 60 ° C.

The coating method of the present invention is not particularly limited, and can be applied according to a conventional method. For example, it is preferable to perform the recoating twice or more so that the dry film thickness becomes 100 to 400 μm. In this case, if the film thickness is less than 100 μm, it is difficult to obtain good anticorrosion performance. On the other hand, if it exceeds 400 μm, cracks occur, the solvent is hardly removed at the time of drying, and problems such as swelling are caused. Therefore, it is preferable to select and use as appropriate according to the situation.

[0022]

EXAMPLES 1 to 4 Phenylmethyl straight silicone resin (37.5% by weight), solvent (xylene) (37.5% by weight), anticorrosion pigment (1% by weight), glass powder having an average particle diameter of 40 .mu.m and a fiber length of 300%.
Using a glass fiber having a diameter of 10 μm and a glass fiber having a diameter of 10 μm, a heat-resistant coating material was trial-produced at the compounding ratio shown in Table 1.

The PWC of the paint was adjusted to 40% by weight by supplementing kaolin as another pigment.
(PWC: Pigment content in coating film components (% by weight)) The above-mentioned trial heat-resistant paint was applied three times with a brush to a 150 × 150 × 4 mm iron plate which had been ground-adjusted by sandblasting to prepare a test piece. . After drying the specimen at 300 ° C., the dried film thickness was measured and found to be about 200 μm on average.

In order to evaluate the heat resistance of the prototype paint, the specimen coated with the paint was placed on a plate heater adjusted so that the surface temperature of the iron plate was 310 ° C., and was heated once every 10 minutes. , And a watering test was performed 200 times. The results are shown in Table 1.

As can be seen from Table 1, Examples 1 to 4
The appearance was good without crack peeling or the like. Furthermore, the specimens subjected to the watering test were placed in a combined cycle tester according to JASO (M-609-91) and subjected to a corrosion resistance test for 24 hours. Showed that the coating was sound. (JASO: Japanese Automobile Standards, M-609-91: Automotive Material Corrosion Test Method)

Examples 5 to 8 The glass fiber of Example 1 was prepared using a fiber length of 1000 μm and a fiber diameter of 1
A heat-resistant paint was trial-produced in the same manner as in Example 1 except that the composition was changed to 0 μm and the mixing ratio shown in Table 2. Further, Example 1
Specimens were prepared in the same manner as described above and subjected to a water hanging test. These results are also shown in Table 2. As a result, Examples 1 to
Similar to Example 4, good results were obtained for Examples 5 to 8.

Example 9 31.1% by weight of silicone resin used in Example 1, 5.2% by weight of glass powder, 7.0% by weight of glass fiber, and mica having a flake diameter of 340 μm and an aspect ratio of 80 8.
9% by weight, dispersant 1.0% by weight, rust preventive pigment 1.4% by weight, talc 5.0% by weight, flaky aluminum powder 6.2% by weight, solvent (xylene) 34.2% by weight at room temperature The mixture was mixed to produce a heat-resistant paint. The PWC is 52.7% by weight.
Met.

The above-mentioned trial heat-resistant paint was applied four times to a 150 × 150 × 4 mm iron plate which had been subjected to sand blasting to prepare a test piece. After drying the obtained specimen at 300 ° C., the dried film thickness was measured.
Micron.

In order to evaluate the heat resistance of the prototype paint, the specimen coated with the paint was placed on a plate heater set to a temperature of 330 ° C. on the iron plate, and once a hour in a heated state The test was carried out 500 times with water at a ratio of.

As a result, the appearance was good without crack peeling or the like. Further, following the above water hanging test, Examples 1 to
The specimen was placed in a combined cycle tester and subjected to a corrosion resistance test for one month in the same manner as in Example 4. As a result, no rust was generated, and it was proved that the coating film was sound by watering.

Comparative Examples 1 to 4 As compared with Examples 1 to 4 , the same resin 37.5% by weight, solvent 37.5% by weight, anticorrosive pigment 1% by weight, glass powder and glass fiber content Was changed to produce a paint, and an evaluation test was performed in the same manner as in Examples 1 to 4. The results are shown in Table 3. As a result, cracking and peeling occurred in all cases by watering 10 times.

Comparative Examples 5 to 8 As compared with Examples 5 to 8, 37.5% by weight of the same resin, 37.5% by weight of solvent and 1% by weight of anticorrosive pigment contained glass powder and glass fiber. Was changed to produce a paint, and an evaluation test was performed in the same manner as in Examples 1 to 4. The results are shown in Table 4. As a result, cracks and peeling occurred in all cases up to 10 times with water.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

Claims (4)

[Claims] (1) 20 to 60% by weight of a silicone resin, 1 to 25% by weight of glass powder having an average particle diameter of 100 μm or less, 0.3 to 25% by weight of glass fiber having a fiber length of 100 to 3000 μm, and a fiber diameter of 1 to 50 μm. A heat-resistant coating composition comprising 0.1 to 10% by weight of a pigment, 1 to 30% by weight of another pigment, and 20 to 60% by weight of a solvent. 2. The silicone resin according to claim 1, wherein the silicone resin is a phenylmethyl straight silicone resin, a modified silicone resin selected from alkyd-modified, polyester-modified, epoxy-modified and urethane-modified, or a combination of these resins. Heat-resistant paint composition. 3. The heat-resistant pigment according to claim 1, wherein the anticorrosion pigment is selected from the group consisting of pollution-free pigments such as zinc phosphate, aluminum phosphate, calcium phosphate, magnesium phosphate, zinc molybdate, calcium molybdate and the like. Paint composition. 4. The other pigment is selected from the group consisting of glass flakes, mica, scaly iron oxide, scaly pigments such as scaly aluminum powder, talc, kaolin, clay, precipitated barium sulfate and calcium carbonate. The heat-resistant coating composition according to claim 1, further comprising an extender.