JPH11323184A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating agent that has excellent heat resistance, weldability, corrosion resistance, durability and flexibility and is capable of being simply applied in a comparatively short time. SOLUTION: A coating composition comprises as the main components (A) a polysilicic acid sol using an organic solvent as a dispersion medium, (B) a powder of one or more metals selected from zinc, magnesium, aluminum, zirconium, tin, copper, iron and silver and a powder of an alloy of each one of these metals with the other metal or metals or with a metal other than these metals and (C) one or more fibers selected from an alkali titanate fiber, a potassium titanate aluminate fiber, a aluminum borate fiber and a magnesium borate fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a coating composition. More specifically, the present invention relates to a coating composition having excellent heat resistance, welding workability, corrosion resistance, durability, and flexibility, which is particularly useful for protecting metal materials.

[0002]

2. Description of the Related Art Buildings such as bridges and plants,
Various coating materials have been proposed for the purpose of protecting steel materials used for exterior materials and structural materials of ships and vehicles.

[0003]

Many of these methods use a resin as a binder, but when a resin is used as a binder, they have a disadvantage that heat resistance is poor. That is, even when a silicone-based resin having relatively excellent heat resistance is used as a binder, in an environment where the resin is exposed to a high temperature of 500 ° C. or more for a long period of time, its corrosion resistance and durability are insufficient, and it is not practical. I can't stand it. Furthermore, when a conventional coating material containing an organic substance is applied to a steel sheet, sparks are scattered when the steel sheet is welded and fused, and the coating film on the peripheral portion and the back surface is widely damaged. There was a drawback that a great deal of work was required for removal and repainting. Such a drawback is particularly problematic in bolted portions of H-section steel and the like.

On the other hand, as a coating material containing an inorganic substance as a main component, for example, a coating material containing potassium titanate fiber and silica sol as main components is disclosed in JP-A-57-106771. However, although this is excellent in heat resistance, it has a disadvantage that the flexibility of the coating film is poor. Therefore, there is a disadvantage that the coating film is peeled or cracked when an external impact or stress is applied to the base material or when expansion and contraction due to heat are repeated. In addition, JP-A-57-106
The coating material of No. 771 does not have sufficient rust-preventing ability, so that it cannot exhibit satisfactory performance for coating a metal material.

[0005] A coating composition containing a metal oxide and a silane coupling agent has also been proposed (for example, JP-A-8-31401). However, this has a drawback that sufficient heat resistance cannot be imparted because it contains a large amount of organic substances, and that the fusing property is impaired. The object of the present invention is heat resistance, weldability,
An object of the present invention is to provide a coating material which is excellent in corrosion resistance, durability and flexibility and can be easily applied in a relatively short time.

[0006]

The present invention provides (A) a polysilicate sol containing an organic solvent as a dispersion medium, and (B) one or two kinds selected from zinc, magnesium, aluminum, zirconium, tin, copper, iron and silver. Powders of the above metal powders and alloys of each of these or other metals (C) One or more fibers selected from alkali titanate fibers, potassium aluminate fibers, aluminum borate fibers, and magnesium borate fibers As a main component.

The present invention also relates to (B) zinc, magnesium, aluminum, zirconium, tin, copper, iron, and silver selected from (A) 100 parts by weight in terms of solid content of a polysilicate sol containing an organic solvent as a dispersion medium. 30 to 500 parts by weight of one or more metal powders and powders of alloys with each or other metal (C) From alkali titanate fiber, potassium aluminate fiber, aluminum borate fiber, magnesium borate fiber One or more selected fibers 1 to 300
And (D) 1 to 20 parts by weight of water. ADVANTAGE OF THE INVENTION According to the coating composition of this invention, the coating film of the aspect which reinforced the metal powder pseudo-coated with polysilicic acid sol with a fibrous material which has not existed conventionally can be formed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Each component of the coating composition of the present invention will be described below. (A) In a polysilicate sol using an organic solvent as a dispersion medium, examples of the organic solvent used as a dispersion medium include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol, One or more solvents selected from ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, and dimethylacetamide can be exemplified. Preferably, a hydrophilic, low-toxic, low-flammable organic solvent is used, and specific examples thereof include isopropyl alcohol, toluene, and xylene.
Examples thereof include a mixed solvent of n-butanol, ethylene glycol monoethyl ether, and ethylene glycol mono-n-propyl ether.

The dispersoid (solid content) usually has a particle size of 1
~ 150 nm, preferably 10-20 nm silica (S
iO ₂ ). The solid content may be 1 to 55% by weight, preferably 15 to 45% by weight. The polysilicate sol using an organic solvent as a dispersion medium can be produced, for example, by adding an organic solvent to an aqueous polysilicate sol and replacing the organic solvent with water by means such as azeotropic reflux or drying under reduced pressure.

In the present invention, (B) one or more metal powders selected from zinc, magnesium, aluminum, zirconium, tin, copper, iron, and silver, and powders of alloys of each of these or other metals are used. You. Powders of these metals or their respective alloy powders are preferred. Examples of the alloy powder include a powder composed of two or more alloys selected from zinc, magnesium, aluminum, zirconium, copper, iron, and lead, and a stainless powder that is an alloy of iron with chromium or nickel. Particularly preferably, zinc powder or zinc flake is used.

As these powders, various shapes such as particles, flakes, fibers and the like can be used. For the particles, an average particle diameter of 0.1 to 50 μm, preferably 1 to 10 μm is used. Things are used. For flakes, the major axis is 1-300 μm, and the minor axis is 1-2.
One having a thickness of 00 μm and a thickness of 0.1 to 5 μm can be exemplified. Examples of the fibrous material include those having an average fiber diameter of 0.1 to 20 μm and an average fiber length of 0.5 to 5000 μm.

These metal powders and alloy powders need to be oxidized on the surface, but do not need to be oxidized in particular, and oxidization on the order of ordinary commercial products is sufficient. Incidentally, it is not preferable that the oxide film becomes brittle and thick when the above-mentioned powder is left under high temperature and high humidity. The blending amount of the component (B) is preferably 30 to 500 parts by weight, and more preferably 50 to 350 parts by weight in terms of solids, based on 100 parts by weight of the solids in the component (A). Is particularly preferred. By setting the blending amount of the component (B) to the above ratio, a coating composition having both good workability and high film strength can be obtained.

(C) One or more fibers selected from alkali titanate fibers, potassium aluminate fibers, aluminum borate fibers, and magnesium borate fibers are used to improve the film strength in the coating agent of the present invention. It contributes to giving flexibility. As the shape of these fibers, the average fiber diameter is 0.1 to 10 μm, and the average fiber length is 10 to 30.
It is preferably 0 μm. Particularly preferably, the average fiber diameter is 0.1.
Those having an average fiber length of 1 to 0.5 μm, an average fiber length of 5 to 50 μm, and an average aspect ratio of 10 or more are used.

Among these fibers, alkali titanate fibers represented by the general formula M ₂ O.nTiO ₂ (where M is an alkali metal and n is 4 or more) are preferred from the viewpoints of film-forming properties and heat insulating properties. Examples of the alkali titanate fiber include a potassium titanate fiber, a sodium titanate fiber, and a lithium titanate fiber, and preferred specific examples thereof include a potassium hexatitanate fiber and an octapotassium fiber. The amount of the component (C) is preferably from 1 to 300 parts by weight, more preferably from 15 to 100 parts by weight, based on 100 parts by weight of the solids in the component (A). . If the amount is too small, the film-forming properties and the reinforcing properties are not sufficient, which is not preferable. On the other hand, if the amount is too large, the viscosity increases, and the workability and the paintability deteriorate, which is not preferable.

The components (A), (B), and (C) of the present invention surprisingly form a good coating having both flexibility and strength, due to the presence of a trace amount of water, each of which is firmly bound. Form. Particularly when applied to a metal substrate, a coating having extremely high adhesion and strength can be formed. It is considered that this is because the partially oxidized metal base material surface functions similarly to the component (B) and participates in the curing mechanism.

However, if the water content is too high, the reaction proceeds rapidly and the viscosity increases significantly in a short period of time, making it difficult to uniformly mix the components and shortening the pot life (working time), thereby increasing workability. The problem of exacerbation arises.
In addition, the coating film after curing is not uniform, heat resistance and fusing properties are poor,
In addition, there arises a problem that the adhesion and strength of the coating to the substrate become insufficient. Further, when the water content is too small, there is a problem that the curing does not proceed or requires a remarkably long time. Therefore, in the coating composition of the present invention, the blending amount of (D) water is a very important point.

That is, (D) the content of water is such that the content in the total composition is 1 to 100 parts by weight of the solid content in the component (A).
To 20 parts by weight, preferably 1 to 15 parts by weight. The water content specified here is contained in the water contained in the organic solvent used as the dispersion medium of the component (A), the attached water contained in the inorganic powder of the components (B) and (C), and other components. This value includes moisture.

The coating composition of the present invention contains, in addition to the above-mentioned components, a rust preventive such as aluminum phosphate and zinc molybdate, and an inorganic light-stable material such as cerium as long as the effects of the present invention are not impaired. An agent, a pigment such as titania, titanium white, titanium yellow, red iron oxide, chrome oxide green, and graphite, and an inorganic filler such as mica, talc, clay, fumed silica, and bentonite may be added. The amount of each of these is preferably in the range of 0.01 to 20 parts by weight in terms of the solid content based on 100 parts by weight of the solid content in the component (A). Further, the coating composition of the present invention may be blended with various organic solvents for the purpose of adjusting the specific gravity and viscosity, or as a dispersion medium for a multi-liquid type described below. As such an organic solvent, for example, the same solvents as those exemplified as the dispersion medium for the component (A) can be used.

Further, the coating composition of the present invention includes:
Methoxy silicate as long as the effects of the present invention are not impaired,
Metal esters such as alkoxysilicates such as ethoxysilicate, titanium alcoholate, aluminum alcoholate and zirconium alcoholate can be blended. These contribute to accelerating curing, improving workability by imparting viscosity, and function as an auxiliary binder after film formation. However, when these are added, the cured coating film contains an organic substance, and thus has a disadvantage that heat resistance is reduced. Therefore, when these are blended, they are limited to applications generally used in the temperature range up to 500 ° C., and their blending amounts are less than 20% by weight, preferably less than 5% by weight in terms of solids in the total solids. It is preferred that

The coating composition of the present invention can be produced, for example, by mixing and stirring each component using a tumbler or a mixer. During storage and distribution, the coating composition of the present invention may be used as two or more liquids, and mixed immediately before use. When the coating composition of the present invention is used in a two-pack type, the first liquid mainly contains (A),
(B) The component is contained, and the second liquid mainly contains (C),
It is preferable to use two liquids containing the component (D), a pigment, an organic solvent and other components.

The coating method of the coating composition of the present invention is carried out by using a neat solution or, if necessary, diluting with various organic solvents, by brush, roll brush, air spray, airless spray, dip coating, etc. Can be. One coating thickness of the coating composition of the present invention is 10 to 200.
The thickness can be set to about 0 μm, preferably 15 to 50 μm, and the layer can be appropriately coated as needed. The coating composition of the present invention can be cured at room temperature after coating on an object, but can be heated as necessary to promote curing.

[0022]

The present invention will be described below with reference to examples and comparative examples. It is to be noted that “parts” means “parts by weight”. Examples The inorganic coating materials of the examples were prepared by blending the components in the proportions shown in Tables 1 and 2. The ratios in the table indicate solid content-converted weights. Examples 4-6, 8 and 9 were adjusted by adding deionized water during sample preparation to achieve the required moisture level. In the test, aging was performed for 7 days after adding the conditioned water. The total water content in the table is the sum of the water content and the added water (adjusted water) in the components A to C, and is the amount based on 100 parts by weight of the component A in terms of solid content.

* 1: Methanol dispersed silica sol manufactured by Nissan Chemical Co., Ltd. * 2: Isopropyl alcohol dispersed silica sol manufactured by Nissan Chemical Co., Ltd. * 3: Xylene / n-butyl alcohol mixed solution dispersed silica sol manufactured by Nissan Chemical Co., Ltd. * 4: Silica sol dispersed with methyl ethyl ketone, manufactured by Nissan Chemical Co., Ltd. * 5: Silica sol dispersed with methyl isobutyl ketone, manufactured by Nissan Chemical Co., Ltd. * 6: Ethylene glycol mono-n, manufactured by Nissan Chemical Co., Ltd.
-Propyl ether-dispersed silica sol * 7: Self-hardening ethyl silicate VP2255 manufactured by Wacker Chemicals East Asia Co., Ltd. * 8: Manufactured by Hakusui Chemical Industry Co., Ltd. * 9-11: Toyo Aluminum Co., Ltd. * 12-15: Otsuka * 16: Nippon Aerosil Co., Ltd., White Carbon * 17: Shiraishi Industry Co., Ltd. * 18: Kusumoto Chemical Co., Ltd., Dispalon 6900-20
X (Anti-precipitating agent) * 19: BERND SCHWEGMANN, Schwego Wet 8075 (wetting agent)

[0024]

[Table 1]

[0025]

[Table 2]

Comparative Example Each of the components shown in Tables 3 and 4 was blended to prepare an inorganic coating material of Comparative Example. The ratios in the table indicate solid content-converted weights. Comparative Examples 5, 6, 8, and 9 were adjusted by adding deionized water during sample preparation to achieve the required moisture level. In the test, aging was performed for 7 days after adding the conditioned water. * 20: Nippon Shokubai Co., Ltd. (silica sol coated with an organic polymer) * 21: Nissan Chemical Co., Ltd. (aqueous silica sol) * 22: Tika Corporation anatase-type titanium dioxide

[0027]

[Table 3]

[0028]

[Table 4]

In Example 1, 30 parts by weight of potassium hexatitanate fiber, 69.5 parts by weight of ethylene glycol monoethyl ether, and Disparon 6900-20X 0.2 part by weight.
5 parts by weight are weighed into a container and about 3
After the dispersion was performed for 0 minutes, rolling was performed twice with a small ice-cooled three-roll mill to prepare a dispersion paste of potassium titanate 6 fiber. On the other hand, to 327 parts by weight (100 parts by weight in terms of solid content) of methanol silica sol, 10.7 parts by weight of Disparon 6900-20X is added, and the mixture is dispersed for about 10 minutes with a small disper. Then, 365 parts by weight of zinc dust-F is added and further added for 10 minutes. After the stirring was continued, 173.3 parts by weight of the potassium hexatitanate fiber dispersed paste (52 parts by weight as potassium hexatitanate fiber) was added, and the mixture was stirred for about 5 minutes to prepare.

Examples 2-3 In the same manner as in Example 1, 327 parts by weight of XBA-ST (100 parts by weight in terms of solid content), Disparon 6900-20X
Add 10.7 parts by weight, disperse with a small disper, then add the indicated amount of zinc dust and disperse. Add 360 parts by weight of potassium hexatitanate fiber paste described in Example 1 to the dispersion and mix uniformly. And prepared. Example 3
Was prepared. Ethylsilicate VP2255 is XB
Added into A-ST and mixed.

Example 4 83.3 Potassium hexatitanate fiber paste obtained in Example 1 was used to adjust the total water content in the ingredients to a desired amount.
Add 1.6 parts by weight of deionized water to parts by weight,
After mixing and uniforming, aged for 7 days in the room,
Example 4 was obtained according to Example 1.

Example 5 In this example, too, deionized water was added at a ratio of 0.9 part by weight to 83.3 parts by weight of potassium hexatitanate fiber paste according to Example 4 in order to adjust the total water content. Tested.

Example 6 A paste was prepared by adding deionized water to a desired amount of water according to Examples 4 and 5, and a sample was prepared according to Example 1.

Example 7 Mica C1000 was added together with an aluminum paste RZA035 in a predetermined amount to IPA-ST in which Schwego Wet 8075 was melted, dispersed by a small disper for about 10 minutes, and a predetermined amount of potassium hexatitanate fiber paste was added. Prepared.

Examples 8 to 9 In order to adjust the water content to a desired amount, deionized water was added to 207 parts by weight of potassium titanate fiber paste in Reference Example 8, 1.0 parts by weight, and in Reference Example 9, 6 parts by weight. It was prepared according to Example 1 by adding 1.2 parts by weight to 210 parts by weight of potassium titanate fiber paste.

Example 10 8 Potassium titanate fiber was prepared according to the formulation described in
Make potassium titanate fiber paste and disperse zinc powder IPA-
It was prepared by mixing with ST sol.

Example 11 A container was weighed in a proportion of 40 parts by weight of potassium titanate aluminate fiber, 59.5 parts by weight of ethylene glycol monoethyl ether, and 0.5 part by weight of Disparon 6900-20X, and the same procedure as in Example 1 was carried out. Then, a potassium titanate aluminate fiber paste was prepared, and a sample was prepared according to Example 1. Aerosil 135 was added and dispersed after the addition of zinc dust-F. Example 12 It prepared according to Example 7 using the potassium titanate aluminate fiber paste.

Example 13 Aluminum borate fiber 50 parts by weight, ethylene glycol monoethyl ether 49.5 parts by weight, Dispalon 6
900-20X 0.5 parts by weight is weighed into a container,
An aluminum borate fiber paste was prepared according to Example 1, and mixed with an IPA-ST sol-dispersed zinc powder solution.

Example 14 117 parts by weight of the potassium titanate fiber paste described in Example 1 and 87.5 parts by weight of the potassium titanate aluminate fiber paste described in Example 11 were mixed and homogenized. Example 14 was obtained by mixing the IPA-ST sol dispersion obtained as described above.

Comparative Example In the same manner, the inorganic coating material of the comparative example was prepared by blending the respective components in the proportions shown in Tables 3 and 4. Except for Comparative Example 10, each sample of Comparative Example was prepared in accordance with the procedure for preparing the samples of Examples of Tables 1 and 2. In Comparative Example 10, 80 parts by weight of potassium titanate fiber, 15 parts by weight of mica C1000 and 6.3 parts by weight of antigel (16%) were weighed in a container with 488 parts by weight of Snowtex-0, and were weighed in a container. A slurry obtained by adding a small amount of clear water to zinc dust was added to the paste obtained by mixing for 30 minutes, and the mixture was prepared by mixing.

Test Example 1 Each of the coating materials obtained in Examples and Comparative Examples was polished with sandpaper # 40 and washed with toluene, 150 × 5.
0 × 0.4 mm steel plate (JIS K5410 SPCC1
505004) with a brush twice, cured in a room for 7 days, and then tested. The results are shown in Tables 5 to 8. The test method was as follows.

Miscibility: Evaluated by the difficulty of mixing when the fiber paste and the metal powder-dispersed organosol are added at a predetermined ratio. Storage stability: The pot life of the above mixture (coating material) was measured. Coating workability: JIS K5400 6.1 (brush coating) Drying property: JIS K5400 6.5 Dry film condition: Visual judgment Tape sticking test: A cellophane tape is strongly adhered to the surface of the film and pressed. Immediately pull it apart strongly and observe the peeling of the coating. Pencil scratching value: JIS K5400 8.4.2 Adhesion: JIS K5400 8.5.2

[0043]

[Table 5]

[0044]

[Table 6]

[0045]

[Table 7]

[0046]

[Table 8]

Test Example 2 After the same ground adjustment was performed on the entire surface of the above-described steel plate, Examples 3, 6, and 7 were air-sprayed twice on the entire surface and cured in a room for 7 days. Table 9 shows the results of the evaluation test.

[0048]

[Table 9]

* A: Each sample was placed in an electric furnace maintained at a furnace temperature of 700 ± 50 ° C. for 30 minutes, taken out and allowed to return to room temperature, and the state of the coating film was observed to observe cracks and peeling. The presence or absence was evaluated. From the results of the evaluation tests of Samples 1 to 3 shown in Table 9, it is understood that the inorganic coating material of the present invention is an excellent complete inorganic coating material that can be sufficiently used.

[0050]

The coating composition of the present invention has heat resistance,
It has excellent flame resistance, weldability, corrosion resistance, durability, and flexibility, so it is useful for coating metal substrates such as steel plates, zinc plates, and galvanized steel, especially chimneys, electric dust collectors, various kilns,
Excellent performance for coating high temperature components such as automobile or aircraft engines or exhaust pipes.

The coating composition of the present invention exhibits stable performance in a use environment up to about 800 ° C., and has the flexibility to expand and contract following the distortion and thermal expansion and contraction of the base material. Almost no occurrence occurs. Further, the coating composition of the present invention may be heated to a temperature higher than the melting point of the component (B), for example, when zinc powder is used as the component (B).
20 ° C or higher], the coating surface that comes into contact with the outside air thermally expands and forms an oxide film to block air, and the vicinity of the bonding portion with the substrate is similar to a hot-dip plating process. The base material protection layer is formed to form an excellent base material protection structure as a whole.

Further, in the case of steel and zinc plates coated with the coating composition of the present invention, the generation of sparks during welding fusing is reduced, and the peeling around the welding fusing site and the back surface is very slight, so that the post-casting process and the like can be performed. The recoating process can be greatly simplified as compared with the conventional case. Further, when the coating composition of the present invention is overcoated with another coating material or the coating material of the present invention after cured film formation,
Since it has the characteristics that it is excellent in adhesion and hardly causes problems such as peeling, it is highly useful as an undercoat material.

[Procedure amendment]

[Submission date] June 17, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0003

[Correction method] Change

[Correction contents]

[0003]

Many of these methods use a resin as a binder, but when a resin is used as a binder, they have a disadvantage that heat resistance is poor. That is, even when a silicone-based resin having relatively excellent heat resistance is used as a binder, in an environment where the resin is exposed to a high temperature of 500 ° C. or more for a long period of time, its corrosion resistance and durability are insufficient, and it is not practical. I can't stand it. Furthermore, when a conventional coating material containing an organic substance is applied to a steel sheet, sparks are scattered when the steel sheet is welded and fused, and the coating film on the peripheral portion and the back surface is widely damaged. It had a disadvantage that it takes a great deal of time and effort in the job removed by.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005] A coating composition containing a metal oxide and a silane coupling agent has also been proposed (for example, JP-A-8-31401). However, these have a disadvantage that they cannot contain sufficient heat resistance because they contain a large amount of organic substances, and further impair weld fusing properties. An object of the present invention is to provide a coating material which is excellent in heat resistance, weldability, corrosion resistance, durability, and flexibility and can be easily applied in a relatively short time.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0029

[Correction method] Change

[Correction contents]

In Example 1, 30 parts by weight of potassium hexatitanate fiber, 69.5 parts by weight of ethylene glycol monoethyl ether, and Disparon 6900-20X 0.2 part by weight.
5 parts by weight are weighed into a container and about 3
After performing 0 minutes dispersion, then subjected to two times the dispersion in a small water-cooled three-roll mill to prepare a 6 potassium titanate fibers dispersed paste. 327 parts by weight (solid conversion 10
0 parts by weight) to methanol silica sol
After adding 10.7 parts by weight of 00-20X and dispersing for about 10 minutes with a small disper, then adding 365 parts by weight of zinc dust-F and continuing stirring for further 10 minutes, the above-mentioned potassium hexatitanate fiber dispersed paste 173.3 Parts by weight (52 parts by weight as potassium hexatitanate fiber) were added, and the mixture was stirred for about 5 minutes to prepare.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction contents]

[0050]

The coating composition of the present invention has heat resistance,
It has excellent flame resistance, weldability, corrosion resistance, durability, and flexibility, so it is useful for coating metal substrates such as steel plates, zinc plates, and galvanized steel, especially chimneys, electric dust collectors, various kilns,
Excellent performance for coating high temperature to become member of the exhaust pipe of automobiles and aircraft.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction contents]

[0052] Further steel, zinc plate, etc. coated with the coating composition of the present invention is reduced the occurrence of sparks during welding fusing, also welding fusing site near or rear surface of the peeling 及
Since the amount of sputtering and sputtering is very small, the post-casting process and the re-coating process can be greatly simplified as compared with the conventional case. In addition, the coating composition of the present invention has a feature that when applied over another coating material or the coating material of the present invention after cured film formation, it has excellent adhesiveness and hardly causes problems such as peeling. Therefore, it is highly useful as an undercoat material.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kazuto Uemura 463 Kagasuno, Kawauchi-cho, Tokushima City, Tokushima Prefecture Inside the Otsuka Chemical Co., Ltd. Tokushima Plant

Claims (5)

[Claims] (A) a polysilicate sol containing an organic solvent as a dispersion medium; and (B) one or more metal powders selected from zinc, magnesium, aluminum, zirconium, tin, copper, iron and silver, and each of them. Or powder of an alloy with another metal (C) containing, as a main component, one or more fibers selected from alkali titanate fibers, potassium aluminate fibers, aluminum borate fibers, and magnesium borate fibers A coating composition comprising: 2. A component selected from zinc, magnesium, aluminum, zirconium, tin, copper, iron, and silver (B) based on 100 parts by weight of a solid content of a polysilicate sol containing an organic solvent as a dispersion medium. 30 to 500 parts by weight of powder of two or more kinds of metal powders and alloys of each of them or other metals (C) selected from alkali titanate fiber, potassium aluminate fiber, aluminum borate fiber, magnesium borate fiber One or more fibers 1 to 300
Parts by weight and (D) 1 to 20 parts by weight of water. 3. The component (B) is one or more metal powders selected from zinc, magnesium, aluminum, zirconium, tin, copper, iron and silver, and powders of alloys thereof. Coating composition. 4. The coating composition according to claim 1, wherein the component (C) is a 6 or 8 potassium titanate fiber. 5. A polysilicic acid sol containing (A) an organic solvent as a dispersion medium is methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol, ethylene glycol monoethyl. Silica content of 15 to 45% by weight using one or more solvents selected from ether, ethylene glycol mono-n-propyl ether and dimethylacetamide as a dispersion medium
The coating composition according to any one of claims 1 to 4, which is a polysilicate sol.