JP5564211B2 - Film forming method and film forming body - Google Patents

Description

  The present invention relates to a method for forming a coating on a metal roof of an existing building.

Conventionally, various materials such as clay tiles, cement tiles, slate tiles, asphalt singles, metal plates, and the like are used as roofing materials in buildings such as houses, factories, and warehouses. Of these, tiles such as clay tiles are materials that have been used for a long time, but the weight per piece is large and the load on the building becomes large, which is somewhat disadvantageous in terms of seismic surfaces. It is.
On the other hand, the roof material made of a metal plate is relatively lighter than the tile material or the like, and has been widely used in various buildings in recent years. As such a metal roof, what coated the surface of the steel plate is used universally. However, in a building using such a metal roof, the sound of rain during the rain tends to be large, which is not preferable from the viewpoint of the living environment.

  As a technique for reducing rain noise on a metal roof, for example, Japanese Patent Laid-Open No. 2000-64512 (Patent Document 1) discloses a heat insulating material made of synthetic resin foam, rubber foam, or the like on the back surface (indoor side) of the metal roof. A method of providing the above is described. Japanese Patent Laying-Open No. 2005-9205 (Patent Document 2) discloses a damping property in which a loss factor is a specific value in a metal roof structure made of a metal roof covering material, a damping adhesive layer, and a base material. A technique for reducing rain noise by using an adhesive is described.

  However, all of the methods described in these patent documents relate to the indoor structure of a metal roof. If these methods are to be adopted in an existing building, it is necessary to modify the attic structure, etc. There is a risk of becoming.

On the other hand, Japanese Patent Application Laid-Open No. 2003-238897 (Patent Document 3) describes a soundproof coating method in which a paint having a soft coating film hardness is applied and then a paint having a hard coating film hardness is applied by lamination. ing. Such a construction method of Patent Document 3 is applied to the outdoor side of a metal roof, and can also be carried out in combination with renovation of the metal roof.
However, as in Patent Document 3, sufficient performance may not be obtained in terms of rain noise reduction or the like simply by laminating a paint with a soft coating film hardness and a hard paint.

JP 2000-64512 A Japanese Patent Laying-Open No. 2005-9205 JP 2003-238897 A

  This invention is made | formed in view of the above problems, and is obtaining the method which can reduce a rain sound simply and effectively in the existing building in which the metal roof was provided.

  In order to solve such problems, the present inventor, as a result of earnest study, on the outdoor side surface of the metal roof of the existing building, if a coating with a specific intermediate coating layer and overcoating layer is formed, it is It has been found that the noise level when raindrops touch the metal roof can be kept low, and the present invention has been completed.

That is, the present invention relates to the following method.
1. For the outdoor side surface of the metal roof in the existing building,
The resin matrix 100 parts by weight derived from the urethane prepolymer, Ri Na inorganic powder or granular material 30 to 300 parts by weight is dispersed, the resin matrix comprises a reaction product of at least the urethane prepolymer and an active hydrogen-containing compound The active hydrogen-containing compound is selected from an amino group-containing compound and a hydroxyl group-containing compound, and forms an intermediate coating layer having a thickness of 50 to 1000 μm.
A method of forming a film, comprising forming an overcoat layer having a contact angle with water of 70 ° or less on the intermediate coating layer.
2. The average particle diameter of the inorganic granular material is 0.1 to 100 μm . The film formation method of description.
3. The inorganic powder having an average particle size of 0.5 to 100 μm is contained in the inorganic powder in an amount of 50% by weight or more based on the total amount of the inorganic powder . Or 2. The method for forming a film according to the above.
4). Above 1. ~ 3. A film forming body obtained by the film forming method according to any one of the above.
5). For the outdoor side surface of the metal roof in the existing building,
An intermediate coating layer having a thickness of 50 to 1000 μm formed by dispersing 100 to 400 parts by weight of inorganic powder particles in 100 parts by weight of a resin matrix derived from a urethane prepolymer is formed on the intermediate coating layer. A method for reducing rain noise, comprising forming an overcoat layer in which a contact angle of water with respect to a film is 70 ° or less.

  ADVANTAGE OF THE INVENTION According to this invention, rain sound can be reduced simply and effectively in the existing building provided with the metal roof. The method of the present invention can also serve as a renovation of a metal roof, and contributes to improving the aesthetics.

  Hereinafter, modes for carrying out the present invention will be described.

The film forming method of the present invention is applied to the outdoor side surface of a metal roof in an existing building.
As a base material constituting the metal roof, for example, a steel plate, a stainless steel plate, an aluminum plate, an aluminum alloy plate, a metal plate such as a copper plate, a zinc-aluminum plated steel plate such as galtite or galvalume, an aluminum plated steel plate, a galvanized steel plate, etc. Examples thereof include a plated metal plate. These may be coated with various paints. The thickness of such a substrate is usually about 0.2 to 2 mm.

In the present invention, an intermediate coating layer may be provided directly on the substrate, but it is desirable to provide an undercoat layer made of a rust preventive paint or the like. By providing such an undercoat layer, corrosion of the metal roof can be prevented, and the effects of the present invention can be obtained over a long period of time.
As the anti-corrosion paint, a resin, an anti-corrosion pigment and the like as essential components can be used. Among these, examples of the resin include vinyl chloride resin, epoxy resin, acrylic resin, urethane resin, acrylic silicon resin, and alkyd resin. Moreover, as a form of resin, a solution type, a dispersion type, or a mixture thereof can be used.

  A commercially available or well-known material can be used as an antirust pigment. Specifically, for example, phosphoric acid-based anticorrosive pigments such as zinc phosphate, iron phosphate, and aluminum phosphate, and phosphorous acid-based anticorrosive pigments such as zinc phosphite, iron phosphite, and aluminum phosphite. , Molybdate anticorrosive pigments such as calcium molybdate, aluminum molybdate and barium molybdate, vanadium anticorrosive pigments such as vanadium oxide, chromate anticorrosives such as strontium chromate, zinc chromate, calcium chromate, potassium chromate and barium chromate Examples include rust pigments. The rust preventive pigment may be mixed at a ratio of usually 5 to 150 parts by weight, preferably about 10 to 100 parts by weight with respect to 100 parts by weight of the resin solid content.

  The undercoat layer can be formed by applying and drying the anticorrosive paint as described above. As a coating method, spray coating, roller coating, brush coating, or the like may be employed as appropriate. What is necessary is just to perform drying under normal temperature (about 0-40 degreeC). The thickness of the undercoat layer is usually about 5 to 200 μm, preferably about 10 to 100 μm.

  In the present invention, an intermediate coating layer is provided on a substrate provided with an undercoat layer as necessary as described above. This intermediate coating layer is formed by an intermediate coating material in which inorganic powder particles are dispersed in a resin matrix derived from a urethane prepolymer. By adopting such a material, in the present invention, it is possible to increase the thickness of the intermediate coating layer, improve the strength, etc., and to exhibit excellent effects in rain noise reduction, adhesion, etc. It becomes.

  The resin matrix derived from the urethane prepolymer in the intermediate coating material is a polymer in which a polymer containing a reaction product of the urethane prepolymer forms a continuous phase. In the present invention, by adopting such a specific resin matrix, it is possible to enhance the rain noise reduction effect and the like.

  Among these, the urethane prepolymer is obtained by reacting a polyol compound and an excess polyisocyanate compound, and has an isocyanate group at the molecular end.

Examples of the polyol compound constituting the urethane prepolymer include polyether polyol and polyester polyol. These weight average molecular weights are 300-5000 (preferably 500-3000) normally.
Moreover, as a polyisocyanate compound, the aliphatic, alicyclic, or aromatic polyisocyanate used for manufacture of a general polyurethane is mentioned. Specifically, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, meta Examples include xylylene diisocyanate and 4,4′-diphenylmethane diisocyanate.

  What is necessary is just to set the reaction ratio of a polyol compound and a polyisocyanate compound to the ratio by which the isocyanate group in a polyisocyanate compound becomes excess with respect to the hydroxyl group in a polyol compound, and NCO / OH is usually 1.2-2. It is desirable to set to about 2.

The resin matrix in the intermediate coating material contains at least a reaction product of the urethane prepolymer and the active hydrogen-containing compound. Among these, the active hydrogen-containing compound is a compound that can react with the isocyanate group of the urethane prepolymer. Examples of such active hydrogen-containing compounds include amino group-containing compounds and hydroxyl group-containing compounds.
Specific examples of the amino group-containing compound include aromatic, aliphatic or heterocyclic polyamines, and epoxide addition-modified products, amidation-modified products, and Mannich-modified products.
Examples of the hydroxyl group-containing compound include a hydroxyl group-containing vinyl compound and a hydroxyl group-containing epoxy compound in addition to polyol compounds such as polyether polyol, polyester polyol, and acrylic polyol. When the urethane prepolymer and the hydroxyl group-containing vinyl compound are reacted, the remaining vinyl groups can be further reacted with each other. When the urethane prepolymer and the hydroxyl group-containing epoxy compound are reacted, the remaining epoxy group can be reacted by further adding an amino group-containing compound or the like. As the hydroxyl group-containing compound, acrylic polyol is particularly suitable.

Examples of inorganic powders include heavy calcium carbonate, precipitated calcium carbonate, kaolin, talc, clay, porcelain clay, china clay, barium sulfate, barium carbonate, quartz sand, quartzite, diatomaceous earth, titanium oxide, zinc oxide, aluminum oxide These can be used, and one or more of these can be used. The average particle diameter of the inorganic granular material is preferably about 0.1 to 100 μm (more preferably 0.2 to 50 μm, still more preferably 0.3 to 20 μm).
As an inorganic granular material in the intermediate coating layer, an inorganic granular material having an average particle diameter of 0.5 to 100 μm (preferably 1 to 50 μm, more preferably 2 to 20 μm) is 50 with respect to the total amount of the inorganic granular material. It is desirable that it is contained by weight% or more (more preferably 70 weight% or more). If the inorganic granular material has such a configuration, it is advantageous in terms of thickening the film and reducing rain noise.

  The inorganic granular material in the intermediate coating layer has a ratio of 30 to 300 parts by weight (preferably 50 to 250 parts by weight, more preferably 80 to 230 parts by weight) with respect to 100 parts by weight of the resin matrix derived from the urethane prepolymer. To do. If the ratio of the inorganic powder particles is within such a range, it is suitable in terms of increasing the thickness of the intermediate coating layer, improving the strength, etc., and obtaining sufficient effects in rain noise reduction, adhesion strength, etc. Is possible. If the inorganic powder is too small, it is difficult to obtain a thick film, and the film strength is insufficient, which may impair rain noise reduction and adhesion. When there are too many inorganic powder granules, it is difficult to obtain a sufficient effect in rain noise reduction.

Such an intermediate coating layer is an intermediate coating material containing a urethane prepolymer, an active hydrogen-containing compound, and an inorganic powder, or a reaction product of an urethane prepolymer and a hydroxyl group-containing epoxy compound, an amino group-containing compound, and an inorganic material. It can be formed by applying and drying an intermediate coating material containing a powder or the like.
Specifically, in the former form of the intermediate coating material, a urethane prepolymer and an active hydrogen compound are mixed at the time of coating, and both are allowed to react in the film formation process, thereby forming a resin matrix. In the latter form of the intermediate coating material, a reaction product of a urethane prepolymer and a hydroxyl group-containing epoxy compound and an amino group-containing compound are mixed at the time of coating, and a resin matrix is formed by reacting both in the film formation process. be able to.
As a method for applying the intermediate coating material, spray coating, roller coating, brush coating, or the like may be employed as appropriate. Drying may be performed at room temperature.

  The thickness of the intermediate coating layer is usually 50 to 1000 μm, preferably 100 to 500 μm. When the thickness of the intermediate coating layer is less than 50 μm, it is difficult to obtain a sufficient rain noise reduction effect. When the thickness is larger than 1000 μm, the load due to the intermediate coating layer is increased, which is disadvantageous in terms of reducing the weight load on the building.

  In the present invention, an overcoat layer having a contact angle with water (hereinafter also simply referred to as “contact angle”) of the formed coating is 70 ° or less is provided on the intermediate coating layer. In the present invention, an excellent rain noise reduction effect can be obtained by laminating the intermediate coating layer and the top coating layer. The mechanism of action is not clear, but the low contact angle of the topcoat layer prevents rebounding when falling raindrops come into contact with the roof, and the cushioning properties of the intermediate coating material act synergistically. Therefore, it is considered that rain noise can be reduced. In the present invention, since the contact angle of the topcoat layer is low, it is considered that a water film is formed on the surface of the topcoat layer during rain, and the splash of raindrops is also suppressed by the water film.

  The topcoat layer has a contact angle of 70 ° or less, preferably 60 ° or less, more preferably 50 ° or less. When the contact angle exceeds 70 °, it is difficult to obtain a sufficient effect in rain noise reduction. In addition, the contact angle with respect to the water of a formation film is a value measured with a contact angle meter.

  Such an overcoat layer can be formed by applying and drying an overcoat material capable of forming a film having a contact angle of 70 ° or less. Specifically, as a top coating material, for example, a resin having a hydrophilic group such as a hydroxyl group, a carboxyl group, an amino group, an amide group, a resin having a hydrophilic segment such as a polyalkylene oxide, a polyoxazoline, or a polyamide is used as a binder. Or those obtained by blending various resins with a hydrophilicity-imparting component. As the resin in the top coating material, for example, a vinyl acetate resin, an alkyd resin, a vinyl chloride resin, an acrylic resin, a urethane resin, an acrylic silicon resin, a fluororesin, or the like or a composite system of these can be used. Among these, at least one selected from acrylic resin, urethane resin, acrylic silicon resin, and fluororesin is particularly preferable. The form of the resin may be either water-based or solvent-based.

Examples of the hydrophilicity-imparting component include inorganic oxide sols and alkoxysilane compounds. Among these, examples of the inorganic oxide sol include aluminum oxide sol, silicon oxide sol, zirconium oxide sol, and antimony oxide sol.
As the alkoxysilane compound, tetraalkoxysilane, a condensate of tetraalkoxysilane, and modified products thereof can be used. The average degree of condensation of the alkoxysilane compound is usually about 1 to 100, preferably about 4 to 20.

Suitable hydrophilicity-imparting components in the present invention include tetraalkoxysilane condensates containing an alkoxyl group having 1 to 2 carbon atoms and an alkoxyl group having 3 to 12 carbon atoms, and in particular the alkoxyl group of the entire compound. Among these, those in which 5 to 50 equivalent% are alkoxy groups having 3 to 12 carbon atoms are preferable. Examples of the alkoxyl group having 3 to 12 carbon atoms include straight chain such as n-propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, n-octyloxy group, and n-dodecyloxy group. Alkoxyl group, isopropoxy group, isobutoxy group, t-butoxy group, sec-butoxy group, isopentyloxy group, neopentyloxy group, isohexyloxy group, 3-methylpentyloxy group, 1-methylhexyloxy group, 1 -Branched alkoxyl groups such as ethylpentyloxy group, 2,3-dimethylbutoxy group, 1,5-dimethylhexyloxy group, 2-ethylhexyloxy group, 1-methylheptyloxy group, t-octyloxy group, etc. . Of these, a branched alkoxyl group is preferred. Such a compound can be obtained, for example, by a method of modifying a tetraalkoxysilane condensate having an alkoxyl group having 1 to 2 carbon atoms by transesterification with an alcohol having 3 to 12 carbon atoms.
Such a hydrophilicity imparting component may be mixed at a ratio of usually 0.1 to 50 parts by weight (preferably 0.5 to 20 parts by weight) with respect to 100 parts by weight of the resin solid content in the top coating material.

  The overcoat layer in the present invention may be either a clear coating or a colored coating, but if it is a colored coating, it can impart a desired color and can also protect the intermediate coating layer. . An overcoat layer formed of such a colored coating can be formed using an overcoat material in which a known pigment or the like is appropriately mixed with the above-described components.

  The overcoat layer in the present invention can be formed by applying and drying the above-mentioned overcoat material. As a coating method, spray coating, roller coating, brush coating, or the like may be employed as appropriate. Drying may be performed at room temperature. The thickness of the overcoat layer is usually 200 μm or less, preferably 10 to 150 μm.

  In the present invention, an intermediate coat layer and an overcoat layer, or an undercoat layer, an intermediate coat layer and an overcoat layer are sequentially laminated on the outdoor side surface of a metal roof in an existing building, and the overcoat layer is formed of a laminated film. Provided on the outermost surface. As long as the effect of the present invention is not significantly impaired, an intermediate layer may be provided between the intermediate coating layer and the top coating layer as necessary.

  Examples and Comparative Examples are shown below to clarify the features of the present invention.

(Manufacture of intermediate coating materials)
・ Inner coating material 1
For 130 parts by weight of urethane-modified epoxy resin (isocyanate-terminated urethane prepolymer (glycidol addition product of polyether polyol (weight average molecular weight 1000) and 2,4-tolylene diisocyanate) and non-volatile content 70% by weight)) , 120 parts by weight of heavy calcium carbonate A (average particle size 3 μm), 24 parts by weight of a hydrocarbon solvent, 1 part by weight of a silicone-based antifoaming agent, and 9 parts by weight of a modified polyamine (solid content 100% by weight) are mixed uniformly. Thus, the intermediate coating material 1 was produced.

・ Intercoat material 2
Soluble acrylic polyol A (hydroxyl value 50 KOH mg / g, glass transition temperature 34 ° C., solid content 46 wt%) 104 parts by weight heavy calcium carbonate A (average particle size 3 μm) 110 parts by weight, hydrocarbon solvent 10 parts by weight, 1 part by weight of silicone-based antifoaming agent, isocyanate-terminated urethane prepolymer A (reaction product of polyether polyol (weight average molecular weight 2000) and 2,4-tolylene diisocyanate, nonvolatile content 100% by weight, NCO The intermediate coating material 2 was produced by uniformly mixing 52 parts by weight) (content 3% by weight).

・ Inner coating material 3
To 225 parts by weight of heavy calcium carbonate A, 25 parts by weight of a hydrocarbon solvent, 1 part by weight of a silicone-based antifoaming agent, and 52 parts by weight of an isocyanate-terminated urethane prepolymer A are uniformly mixed with 104 parts by weight of a soluble acrylic polyol A. Thus, an intermediate coating material 3 was produced.

・ Intercoat material 4
95 parts by weight of heavy calcium carbonate A, 25 parts by weight of titanium oxide A (average particle size 0.3 μm), 10 parts by weight of hydrocarbon solvent, 1 part by weight of silicone-based antifoaming agent, based on 104 parts by weight of soluble acrylic polyol A The intermediate coating material 4 was produced by uniformly mixing 52 parts by weight of the isocyanate-terminated urethane prepolymer A.

・ Intercoat material 5
To 104 parts by weight of soluble acrylic polyol A, 350 parts by weight of heavy calcium carbonate, 40 parts by weight of hydrocarbon solvent, 1 part by weight of silicone-based antifoaming agent, and 52 parts by weight of isocyanate-terminated urethane prepolymer A Thus, an intermediate coating material 5 was produced.

・ Intercoat material 6
To 104 parts by weight of soluble acrylic polyol A, 15 parts by weight of heavy calcium carbonate, 2 parts by weight of hydrocarbon solvent, 1 part by weight of silicone-based antifoaming agent, and 52 parts by weight of isocyanate-terminated urethane prepolymer A Thus, an intermediate coating material 6 was produced.

・ Inner coating material 7
Dimer acid-modified epoxy resin (solid content 70% by weight) 55 parts by weight, heavy calcium carbonate A 120 parts by weight, hydrocarbon solvent 15 parts by weight, silicone-based antifoaming agent 1 part by weight, modified polyamine (solid content 100% by weight) %) The intermediate coating material 7 was produced by uniformly mixing 45 parts by weight.

(Manufacture of top coating materials)
・ Coating material 1
Non-aqueous dispersion acrylic polyol A (hydroxyl value 50 KOHmg / g, glass transition temperature 38 ° C., solid content 50% by weight) 188 parts by weight, titanium oxide A (average particle size 0.3 μm) 80 parts by weight, hydrocarbon type 23 parts by weight of solvent, 1 part by weight of silicone-based antifoaming agent, 6 parts by weight of isocyanurate structure-containing polyisocyanate A (non-volatile content: 100% by weight, NCO content: 21% by weight), and 3 parts by weight of the following hydrophilic component The top coating material 1 was manufactured by mixing.

・ Hydrophilicity imparting component 52 parts by weight of isobutyl alcohol and 0.03 part by weight of dibutyltin dilaurate as a catalyst are added to 100 parts by weight of methyl silicate condensate (weight average molecular weight 1000, average condensation degree 8, non-volatile content 100%). Then, after mixing, a demethanol reaction was performed at 75 ° C. for 8 hours to produce a hydrophilicity-imparting component. The equivalent ratio of methyl group to isobutyl group in the hydrophilicity imparting component was 62:38.

-Contact angle measurement On an aluminum plate of 150 mm x 70 mm x 1 mm, the top coating material 1 is spray-coated so that the dry film thickness is 40 μm, and dried for 7 days in a standard state (temperature 23 ° C., relative humidity 50%). I left it outdoors for a month. About the test plate obtained by the above method, the contact angle was measured using the CA-A type contact angle measuring apparatus by Kyowa Interface Science Co., Ltd. As a result, the contact angle of the top coating material 1 was 33 °.

・ Coating material 2
Non-aqueous dispersion type acrylic polyol B (hydroxyl value 50KOHmg / g, glass transition temperature 32 ° C., solid content 50% by weight) 188 parts by weight, titanium oxide A 80 parts by weight, hydrocarbon solvent 30 parts by weight, silicone-based defoaming The top coating material 2 was manufactured by uniformly mixing 1 part by weight of the agent, 6 parts by weight of polyisocyanate A containing isocyanurate structure, and 1 part by weight of the hydrophilicity-imparting component.
When the contact angle of the topcoat material 2 was measured by the same method as that for the topcoat material 1, the contact angle of the topcoat material 2 was 54 °.

・ Coating material 3
Uniform mixing of 188 parts by weight of non-aqueous dispersion type acrylic polyol A with 80 parts by weight of titanium oxide A, 26 parts by weight of hydrocarbon solvent, 1 part by weight of silicone-based antifoaming agent, and 6 parts by weight of polyisocyanate A containing isocyanurate structure Thus, the top coating material 3 was produced.
When the contact angle of the top coating material 3 was measured by the same method as that for the top coating material 1, the contact angle of the top coating material 3 was 82 °.

(Test Example 1)
・ Noise level test A 300mm × 300mm × 1mm aluminum plate was spray-coated with a rust-preventive primer so that the dry film thickness was 30 μm. After drying for 18 hours in the standard state, the intermediate coating material 1 had a dry film thickness of 200 μm. It was spray-coated so as to become and dried in a standard state for 24 hours. Next, the top coating material 1 was spray-coated so that the dry film thickness was 40 μm, dried in a standard state for 7 days, and then left outdoors for 1 month.
The test plate obtained by the above method was installed horizontally, and water was continuously sprinkled for 1 minute using a shower nozzle from 3 m above. At this time, the noise level was measured with a noise meter installed 10 cm away from the back surface of the test plate. The noise level was evaluated according to the following evaluation criteria.
A: Less than 80 dB B: 80 dB or more and less than 85 dB C: 85 dB or more and less than 90 dB D: 90 dB or more

-Adhesion test A test plate was prepared in the same procedure as the above "noise level test" (however, an aluminum plate having a size of 150 mm x 70 mm x 1 mm was used).
The test plate obtained by the above method was immersed in warm water of 50 ° C. for 72 hours, and then the adhesion was evaluated by a cross-cut tape method according to JIS K 5600-5-6. The evaluation criteria are as follows.
A: The defect area is less than 5% B: The defect area is 5% or more and less than 15% C: The defect area is 15% or more

  The test results are shown in Table 1. In Test Example 1, excellent results were obtained in any test.

(Test Examples 2 to 5)
A test plate was prepared in the same manner as in Test Example 1 except that the intermediate coating material and the top coating material shown in Table 1 were used, and each test was performed. The results are shown in Table 1. In Test Examples 2 to 5, excellent results were obtained in any test.

(Test Examples 6 to 8)
A test plate was prepared in the same manner as in Test Example 1 except that the intermediate coating material and the top coating material shown in Table 2 were used, and each test was performed. The results are shown in Table 2. In Test Examples 6 to 8, sufficient results could not be obtained as compared with Test Examples 1 to 5.

(Test Example 9)
A test plate was prepared in the same manner as in Test Example 1 except that the coating material 1 was directly coated thereon after coating the rust-proof primer, and each test was performed. The results are shown in Table 2. In Test Example 9, sufficient results could not be obtained.

(Test Example 10)
A test plate was prepared in the same manner as in Test Example 1 except that the coating material 2 was directly coated thereon after coating the rust-preventing primer, and each test was performed. The results are shown in Table 2. In Test Example 10, sufficient results could not be obtained.

(Test Example 11)
A test plate was prepared in the same manner as in Test Example 1 except that the intermediate coating material and the top coating material shown in Table 2 were used, and each test was performed. The results are shown in Table 2. In Test Example 11, sufficient results could not be obtained.

(Test Example 12)
The intermediate coating material and the top coating material shown in Table 2 were used, and the intermediate coating material was coated so that the dry film thickness was 30 μm. Except for this, a test plate was prepared in the same manner as in Test Example 1, and each test was performed. The results are shown in Table 2. In Test Example 12, sufficient results could not be obtained.

Claims (4)

For the outdoor side surface of the metal roof in the existing building,
The resin matrix 100 parts by weight derived from the urethane prepolymer, Ri Na inorganic powder or granular material 30 to 300 parts by weight is dispersed, the resin matrix comprises a reaction product of at least the urethane prepolymer and an active hydrogen-containing compound The active hydrogen-containing compound is selected from an amino group-containing compound and a hydroxyl group-containing compound, and forms an intermediate coating layer having a thickness of 50 to 1000 μm.
A method of forming a film, comprising forming an overcoat layer having a contact angle with water of 70 ° or less on the intermediate coating layer. Film forming method according to claim 1, wherein the average particle diameter of the inorganic powder or granular material is 0.1 to 100 [mu] m. Wherein the inorganic powder or granular material, the inorganic powder particles having an average particle diameter 0.5~100μm is, in claim 1 or claim 2, characterized in that included the total amount of the inorganic powder or granular material 50 wt% or more The film formation method of description. Film-forming material obtained by the film forming method according to any one of claims 1-3.