JPS6351998B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention applies a water-soluble alkali metal silicate-based inorganic paint and a curable crack to a mineral base material (hereinafter referred to as mineral material) made of a porous inorganic base material or a non-porous mineral base material such as metal or glass. The present invention relates to a method for forming an inorganic coating film that is finished with a decorative coating using a filling coating liquid. Base materials such as asbestos cement boards and calcium silicate boards are noncombustible and have excellent durability, so they are widely used as building materials and other materials. Generally, these materials themselves have poor cosmetic properties, so when cosmetic properties are required, they are finished with organic paint. However, since this organic coating film is flammable and has poor durability, it significantly impairs the characteristics of the base material. Therefore, nonflammable inorganic paints that can take advantage of the characteristics of these base materials have come into use. However, in general, inorganic paints are superior to organic paints in terms of nonflammability, heat resistance, etc., but are inferior in terms of flexibility, gloss, smoothness, etc. In particular, base materials such as asbestos cement boards and calcium silicate boards undergo large dimensional changes due to changes in atmospheric humidity, water absorption, and expansion and contraction due to drying, and inorganic coatings lack the flexibility to sufficiently follow these dimensional changes. Therefore, cracks are likely to occur, and contaminants penetrate and adhere to the cracks, reducing the contamination resistance. Furthermore, due to the occurrence of cracks, efflorescence components in the base material tend to be eluted onto the coating surface, causing efflorescence.
When the coating film contains an efflorescence component, it is difficult to completely suppress the efflorescence phenomenon. Inorganic paints used for decorative purposes such as building materials include heat-curing types and room-temperature curing types. In general, heat-curing paints cannot produce a sufficiently cured film unless heated to approximately 200 to 300°C, but if an asbestos cement board is used as a base material, such as a calcium silicate board, this heating will cause the base material to harden. strength deterioration, denaturation,
There is a problem with discoloration. Room-temperature curing types rarely deteriorate the substrate, but require a curing period of about one week or more to obtain a sufficiently cured film. According to Japanese Patent Publication No. 49-47249, a highly viscous paint made by adding a considerable amount of amorphous silica to an alkali metal silicate and melting it by heating for a long time is applied to the base material, and after being treated with a strong acid treatment liquid such as acid. A method of dry curing is disclosed. This invention is characterized by the use of a paint in which a large amount of amorphous silica powder is heated and dissolved, and as clearly shown in the comparative examples in the same publication, it is not effective when the silica is not dissolved. Not demonstrated. This method may have some problems regarding the production of the paint, gloss, etc. As one method for solving the above problems, the present inventors first coated a paint containing a water-soluble alkali metal silicate or the like, treated it with an acid solution, and removed the acid.
Next, he invented a method that includes a step of curing the coating after applying the coating (Japanese Patent Application No. 56-211612).
issue). Thereafter, the present invention, etc., as an invention to improve this invention, includes a step of undercoating a water-soluble alkali metal silicate-based aqueous solution paint containing powder solids, a water-soluble alkali metal silicate having a lower powder solid content than the paint. We proposed a method for forming an inorganic coating film, which is characterized by the steps of topcoating with an aqueous solution paint, and at least after the topcoating step, treating with an aqueous acid/ammonium salt solution having a PH value within a predetermined range. −206675). This method solves the problem of low flexibility associated with ordinary inorganic paint films, which makes them prone to cracking, and by uniformly generating fine cracks in the paint film, it disperses and absorbs stress, thus improving stain resistance. This prevents large cracks from occurring. The fine cracks generated here are about 1 μm wide, so there is no problem with stain resistance or water permeability in normal applications, but for special applications, such as kitchens and bathrooms,
This may cause some problems. Therefore, the main object of the present invention is to provide a novel method for forming an inorganic coating film, which is a further improvement over the prior invention (Japanese Patent Application No. 57-206675). More specifically, the object of the present invention is to maintain the nonflammability, heat resistance, gloss and smoothness, flexibility, and efflorescence resistance comparable to organic paint or glass glaze surfaces of the coating film obtained in the prior invention. In addition, it is an object of the present invention to provide a method for forming an inorganic coating film with improved stain resistance and water permeability. To summarize a typical embodiment of the present invention, a water-soluble alkali metal silicate-based aqueous solution paint (hereinafter referred to as an undercoat paint) containing powder solids selected from fillers, pigments, hardeners, etc., is applied onto a mineral base material. ) is applied, dried appropriately, and used as an undercoat, and then a water-soluble alkali metal silicate-based aqueous solution paint for topcoat (hereinafter referred to as topcoat) whose powder solid content is less than that of the undercoat or zero is applied. (hereinafter referred to as "acid/ammonium salt"), apply an aqueous acid/ammonium salt solution with a pH value of about 3.5 to about 10.0, wash with water, and dry (hereinafter referred to as "acid/ammonium salt"). This is a method for forming an inorganic coating film, which is characterized by applying a filling coating solution that hardens after application onto the formed coating film to fill in fine cracks in the coating film. It is preferred that at least the undercoating paint of the above paints contains an effective amount of a curing agent. If necessary, a water-soluble alkali metal silicate-based aqueous solution paint having a solid content between the above two paints may be applied once or more between the two paints (hereinafter referred to as intermediate coat) to form an inorganic paint film. Of course, it is also possible to form Furthermore, the present invention naturally includes an embodiment in which the acid/ammonium salt-based water-soluble aqueous solution treatment is carried out not only after the top coating process but also after the undercoating process and/or after the intermediate coating process. Furthermore, in the present invention, it is naturally possible to use a modified method in which a coating film is formed only by undercoating or topcoating, and then the above-mentioned filling coating liquid is applied to fill the fine cracks. That is, typically
Painting by applying the above-mentioned topcoat and drying it appropriately on a substantially non-porous substrate such as a glass plate, a metal plate, a ceramic plate, or a mineral substrate having an unsatisfactory inorganic coating according to the prior art. It is characterized by applying an acid/ammonium salt aqueous solution having a pH value in the same range to the coating film that has been applied at least once, washing with water, drying, and then similarly applying a filling coating solution and curing it. There is a method for forming an inorganic coating film. Preferably, the coating contains an effective amount of a curing agent. In each of the above embodiments, a strong base-strong acid that acts not only on water but also on the remaining ammonium salt to promote removal (for example, decomposition by chemical reaction) and has virtually no effect on the coating film.・When using a dilute aqueous solution (e.g. about 0.1 to 5% by weight) of salt (e.g. NaCl or KCl) added to water,
Washing time is reduced. The PH value of the acid/ammonium salt aqueous solution mentioned above is
It generally ranges from about 3.5 to about 10.0, preferably from about 4 to about 9, and more preferably from about 4.5 to about 8.5 and typically from about 5 to about 8. Outside the range of about 3.5 to 10.0, the effects of the present invention are generally difficult to achieve. The acid/ammonium salt aqueous solution refers to an aqueous solution of a salt that is a reaction product or reaction product mixture of an acid or an acidic salt and ammonia, aqueous ammonia, or an ammonia compound, and typically includes (1)
Dissolve the acid/ammonium salt in water or (2)
It can be prepared by, for example, adding an acid and ammonia water or ammonia gas to water. In order to adjust the aqueous solution to a desired pH value, for example, ammonia water, ammonia gas, or the acid may be appropriately added to the aqueous solution. If necessary, it is also possible to add a suitable buffer to effectively maintain the desired PH value. Note that the salt component of the acid/ammonium salt aqueous solution may be a mixture of two or more types of salts. As the acid component of the salt of the acid/ammonium salt aqueous solution, inorganic acids and organic acids or acid salts thereof can be used. Examples of inorganic acids include phosphoric acid, hydrochloric acid, sulfurous acid, sulfuric acid, nitric acid, aluminum chloride, aluminum sulfate, Typical examples include monobasic aluminum phosphate, monobasic calcium phosphate, aluminum nitrate, and organic acids such as oxalic acid, citric acid, acetic acid, and tartaric acid, but are not limited to these.
Note that representative acid/ammonium salts include ammonium phosphate, ammonium sulfate, ammonium nitrate, ammonium chloride, ammonium acetate, etc., but in general, primary, secondary, and/or tertiary ammonium phosphates are particularly preferred. . Examples of the base material in the present invention include asbestos cement board, asbestos perlite board, calcium silicate board, asbestos cement calcium silicate board, gypsum board, mortar board, concrete board, pulp cement board, wood chip cement board, GRC (glass fiber reinforced cement) board, CFRC (carbon fiber reinforced cement) board, SFRC (steel fiber reinforced cement)
Includes boards, ALC boards, rock wool inorganic moldings, metal plates, ceramic plates, glass plates, etc. The water-soluble alkali metal silicate-based aqueous solution paint in the present invention is formed by mixing a water-soluble alkali metal silicate-based aqueous solution and powder solids such as a hardening agent, filler, and pigment. The amount of powder solids contained in the primer coating ranges from about 10% or more, and preferably about 30% or more, based on the weight of the coating, to the amount retained as a coating in the aqueous silicate vehicle (e.g., about 80% by weight). Generally about 20 to approx.
Amounts in the range of 60% by weight are used. The amount of powder solids in the topcoat in the embodiments described above ranges from less than about 30% by weight, and usually less than about 20%, and preferably less than about 10%, to zero. The above water-soluble alkali metal silicate usually has the general formula
M ₂ O・xSiO ₂・yH ₂ O (where M is an alkali metal belonging to group of the periodic table, x and y are positive numbers) A modified water-soluble alkali metal silicate modified with a valent metal compound may also be used, and this modified salt is also included in the term water-soluble alkali metal silicate. Water-soluble alkali metal silicates include sodium silicate, potassium silicate, lithium silicate, etc.
Although the value of x is not particularly limited, it is preferably 2 to 5 from the viewpoint of film-forming properties, durability, etc. The value of y is also not particularly limited, and may be within a range that provides appropriate viscosity to the final composition paint.
Alternatively, it may be within a range that does not pose a problem when handling the composition. The modified water-soluble alkali metal silicate is produced by adding oxides, hydroxides, fluorides, carbonates, phosphates, etc. of polyvalent metals such as magnesium, aluminum, calcium, zinc, and zirconium to the water-soluble alkali metal silicate. Some compounds are made by dissolving and reacting one or more compounds, and contribute to improving the water resistance, chemical resistance, etc. of the coating film. The inorganic paint in the present invention includes these water-soluble alkali metal silicates (including modified water-soluble alkali metal silicates).
One type or a mixture of two or more types can be used. Practically speaking, sodium silicate is excellent in terms of film-forming properties, adhesion, low cost, etc., and in the present invention, even when one type of sodium silicate is used, an excellent inorganic coating film can be obtained. The content of the alkali metal silicate in the paint is about 7% or more, preferably about 10% or more, more preferably about 15% or more, based on the weight of the paint.
% or more, and typically ranges from about 15% to about 60%. Hardening agents for the above water-soluble alkali metal silicates (including modified water-soluble alkali metal silicates) include polyvalent metal oxides such as zinc oxide, magnesium oxide, and aluminum oxide; Polyvalent metal hydroxides; polyvalent metal carbonates such as zinc carbonate and magnesium carbonate; polyvalent metal phosphates such as magnesium phosphate, aluminum phosphate, and zinc phosphate; zinc silicofluoride, aluminum silicofluoride, etc. silicofluoride; organic compounds such as glyoxal and oxalic acid amide, and one or more of these curing agents are used. An effective amount of curing agent is about 1% or more, preferably about 3% or more, and typically about 5% or more by weight of each coating. Examples of fillers include granular materials such as silica stone, alumina, and glass powder; flat materials such as clay and mica; and fibrous materials such as asbestos and glass fiber powder. Pigments include titanium dioxide, red iron, yellow lead, chrome green, ultramarine blue, mars violet, cobalt blue, and carbon black. Other additives include known surfactants,
There are dispersants, antifoaming agents, thickeners, etc., and these are added as necessary. The amount of each of the above-mentioned powder solid components other than the curing agent can be appropriately determined as necessary within the range of the total powder solid content required for each coating material. The filling coating liquid that is curable after application may include organic or inorganic materials, mixtures thereof,
Alternatively, solutions or suspensions containing these materials may be used, such as transparent or colored conventional organic paints, liquid resins, silica sols, metal alkoxide hydrolysates, or polysiloxanes, or mixtures, solutions or suspensions thereof. liquid etc. may be used. In addition,
From the viewpoint of heat resistance and/or weather resistance, coating liquids consisting essentially or substantially of inorganic components and/or polysiloxane are generally preferred. The organic paint may be either solvent-based or water-based. Examples include acrylic paint, vinyl paint, urethane paint, silicone paint, etc. Liquid resins include, for example, thermosetting acrylic resin,
Examples include unsaturated polyester resin and epoxy resin. The metal alkoxide hydrolyzate may also include a partial hydrolyzate, or may be a mixture of hydrolysates and/or partial hydrolysates of several metal alkoxides. Examples of the metal alkoxide include tetraethoxysilane, tetraisopropoxytitanium, and tributoxyaluminum. Examples of the polysiloxane include methyltrimethoxysilane, methyltriethoxysilane, and phenyltriethoxysilane. Incidentally, the above-mentioned curable non-efflorescence filling coating liquid is
A coatable liquid (solution or suspension) that dries (naturally or solidifies by heating or irradiation with light/radiation) to form a non-efflorescent solid that fills and adheres to fine cracks. do. Therefore, the curing mechanism may be any of solidification, agglomeration, polymerization, condensation, crosslinking, etc., and drying refers to the state in which the coating liquid hardens and solidifies and adheres to the crack part. means. That is, any filling coating liquid that satisfies these requirements can be used in the present invention. In addition, when using an organic paint or a coating liquid made of a liquid resin, heat resistance etc. are generally improved if a crosslinking type is used. Next, a method for forming an inorganic coating film according to the present invention will be explained. In one embodiment of the present invention, the first layer is obtained by applying a water-soluble alkali metal silicate-based paint to which powder solids such as a hardening agent, filler, and pigment are added;
After the next drying, it does not contain powder solids such as hardeners, fillers, pigments, etc., or it does not contain hardeners, fillers, pigments, etc.
A water-soluble alkali metal silicate paint containing a small amount of thickener etc. was applied to obtain the second layer, and after secondary drying, the above-mentioned
An inorganic coating film is obtained by immersing it in an acid/ammonium salt aqueous solution with a pH value, then immersing it in water or a dilute aqueous solution and drying it, then applying a filling coating solution that hardens into a coating solution and drying it. can be formed. In the above embodiment, since the first layer contains a relatively large amount of solid powder such as a curing agent, a filler, and a green color, a relatively porous coating film can be formed by the primary drying. When this first layer is coated with a water-soluble alkali metal silicate paint that does not contain powder solids or contains small amounts of hardeners, pigments, thickeners, etc.
Part of it penetrates into the first layer and the first layer becomes a dense layer, and a part of it forms a transparent glaze-like thin film on the upper surface of the first layer that does not contain powder solids or contains a small amount of powder solids as a second layer. be done. Thereafter, secondary drying is performed at a temperature that does not cause foaming of the second layer. Furthermore, the alkali metals in the coating film are selectively and forcibly removed by acid ions by immersion in an acid/ammonium salt aqueous solution having the above-mentioned PH value, and the coating film is cured, and a portion of the acid is removed from the coating film. It is thought that it also reacts with the components inside to bring about a hardening effect. after that,
Substances such as residual unreacted acids and ammonium salts in the coating film and base material are removed by immersing the coating film in water or in a dilute aqueous solution, and when this is dried, the coating film shrinks and causes fine cracks. Occurs uniformly. Next, in order to close these minute cracks, the above-mentioned filling coating solution, which is cured after application, is applied onto the coating film. When the coating liquid contains an organic material, it is preferable to remove excess deposits or films on the coating surface after coating. In the case of using only inorganic materials, deposits or formed films may remain. After this operation, drying is performed. In the case of an organic coating liquid, it is also preferable to apply it only to the cracked area as much as possible. Therefore, it is generally preferred that the coating liquid be applied to a thickness sufficient to fill the cracks and not to form an excess coating. In addition, a mode in which acid/ammonium salt aqueous solution treatment is performed even after the above-mentioned undercoating step,
Even in embodiments including an intermediate coating step, embodiments in which only a top coat is applied, etc., the processes and effects are obvious to those skilled in the art. The characteristics of the present invention can be summarized as follows: (1) The surface of the coating film has a transparent glaze-like appearance, and has a good appearance and texture. (2) If a coating film is manufactured by chemically curing with a weakly acidic to neutral acid/ammonium salt aqueous solution, the coating film will harden more uniformly and slowly compared to the heat curing method, so fine particles will be uniformly formed on the coating film. A crack occurs. The cracks generated in this way are usually so fine that contaminants cannot penetrate, and even if the base material undergoes dimensional changes or deflections due to water absorption expansion, drying shrinkage, etc., the uniform cracks disperse and absorb stress. , there are no longer large cracks that cause a decrease in stain resistance, and the stain resistance is good. However, by filling these fine cracks with a coating material according to the present invention, the stain resistance and water permeability (water impermeability) are further improved.
On the other hand, even if the above-mentioned dimensional change or deflection of the base material occurs, the stress is dispersed and absorbed at the boundary between the fine cracks and the coated material, so that the generation of large cracks is prevented. (3) Treatment with an acid or ammonium salt aqueous solution removes alkali metals in the coating film that become efflorescence components, resulting in a coating film with excellent efflorescence resistance. Furthermore, when a cementitious material such as an asbestos cement board or a calcium silicate board is used as the base material of the present invention, the method of the present invention does not require high-temperature heating, and after drying at a relatively low temperature, the above-mentioned PH value acid,・
Since it is cured using an ammonium salt-based aqueous solution, the base material does not deteriorate. Furthermore, since the free Ca component that becomes the efflorescence component in the base material can be fixed with acid, the efflorescence resistance can be improved. Furthermore, base materials containing asbestos or glass fiber as reinforcing materials will not be deteriorated. It is better to add a curing agent to the undercoat paint forming the first layer in order to improve the adhesion with the base material and the curing properties of the topcoat film.
It is better to add solid substances such as fillers to provide functions such as durability and to uniformly generate fine cracks. In this way, the undercoat film layer is
In addition to having the function of a coating film, it also plays the role of allowing the topcoat to penetrate appropriately and reacting with the unreacted curing agent in the undercoat to supplement the hardening of the topcoat. In addition, a surfactant, an antifoaming agent, a thickener, etc. may be added as necessary. Water-soluble alkali metal silicate is also used for the top coat that forms the second layer, but in order to give the dense film stain resistance, gloss, smoothness, aesthetics, etc., hardeners, fillers, etc. Do not add solids or
Alternatively, curing agents, pigments, etc. may be added in small amounts to prevent foaming during heating, coloring, etc., so as not to cause a decrease in the above-mentioned performance. In addition, in the embodiment where only the top coating is used, it is preferable to add the minimum necessary amount of curing agent. It is also desirable to use a water-soluble curing agent (glyoxal) in combination. A curing agent may be included in the filling coating solution, which is cured after application to close the fine cracks formed in the coating film, to promote the effect. The coating liquid can contain solid substances such as fillers and pigments, as long as they are smaller than the width of the fine cracks and can therefore penetrate into the fine cracks (for example, particle size is 0.5 μm or less). The amount of undercoat paint and topcoat paint varies depending on the type of paint, the type of base material, the intended use of the painted board, etc., but for undercoat paint it is usually 20~20~
The amount is enough to form a coating film of 50 μm, and for the top coat, the amount is usually enough to form a coating film of 2 to 5 μm. The amount of coating liquid applied to fill the fine cracks may be sufficient to fill the fine cracks, and is usually 0.1 to 2 mg/cm ² as a dry product. The primary drying of the undercoat after application is sufficient as long as the undercoat dries uniformly, and may be maintained at room temperature to about 100° C. for about 1 minute to 60 minutes. The secondary drying of the top coat after application differs depending on the type of curing agent, but it does not completely cure the paint film and allows the alkali metal components to be selectively and efficiently eluted and removed in the next chemical treatment process, and the top coat does not completely cure. The conditions are such that the layer does not foam. Typically room temperature to approx.
It may be kept at 150°C for about 30 minutes to 48 hours. Drying after filling the fine cracks varies depending on the type of coating liquid used for filling, but it is usually sufficient to maintain the drying process at room temperature to 120°C for about 5 minutes to 5 hours. If the pH value of the acid/ammonium salt aqueous solution is about 3.5 or less, the elution rate of the alkali metal components in the paint film will become rapid, and the elution of paint film components other than the alkali metal components will also become more intense, leading to the occurrence of large cracks. It causes a decrease in strength, durability, gloss, smoothness, and aesthetics. In addition, cement-based base materials and materials with asbestos added as reinforcing materials are more likely to be eroded. When the PH value is about 10.0 or more, components other than the alkali metal components are eluted in large quantities, and the gloss, smoothness, and aesthetics of the coating film are reduced. Usually, the concentration of the acid/ammonium salt aqueous solution as a chemical treatment condition is approximately 0.2 to 0.2 to
about 20% by weight and typically about 0.5 to about 10% by weight
The temperature of the treatment solution is preferably room temperature to about 60°C, and the treatment time is preferably about 1 to 24 hours. In short, regarding the chemical treatment conditions, it is necessary to use a chemical solution that can selectively remove the alkali metal components in the coating film at an appropriate elution rate and has a pH value that does not easily attack the base material components. After chemical treatment with an acid/ammonium salt aqueous solution, the coating film is immersed in water or a dilute aqueous solution to remove unreacted water-soluble substances such as acid/ammonium salts in the coating film and the base material. Generally, immersion in water can be carried out for about 1 to 24 hours. Incidentally, if the material is immersed in the aforementioned strong base/strong acid salt dilute aqueous solution such as saline solution instead of immersion in water, the immersion and removal time can be reduced to approximately half. Hereinafter, typical examples of the present invention will be explained in detail using Examples and Comparative Examples. Example 1A (1) Preparation of paint For the undercoat paint, ingredients other than the sodium silicate aqueous solution, surfactant, and antifoaming agent were mixed in a pot mill for 24 hours from the formulation shown below, and then the rest was added and screw-stirred for 15 minutes. It was prepared by (i) Preparation of undercoating paint Sodium silicate aqueous solution (40% liquid)
100 [parts by weight] Zinc oxide 30 〃 Silica powder 40 〃 Sodium tripolyphosphate 2 〃 Titanium white 20 〃 Water 90 〃 Surfactant (5% liquid) 1 〃 Antifoaming agent (5% liquid) 1 〃 Top coat paint is as follows The formulation shown was prepared by mixing and stirring. (ii) Preparation of top coating paint Sodium silicate aqueous solution (40% liquid)
100 [parts by weight] Water 100 Surfactant (5% liquid) 1 Antifoaming agent (5% liquid) 1 The coating liquid for filling was prepared by mixing and stirring the formulation shown below. (iii) Preparation of coating liquid for filling Acrylic transparent paint Metalac C (product name, manufactured by Fujikura Kasei Co., Ltd.) 50 [parts by volume] Metalac C thinner (solvent) 50 [parts by volume] (2) Painting Undercoat paint Calcium silicate plate (thickness 3mm)
The coating was applied in two parts by air spray to a dry film thickness of approximately 50μm, and then heated at 80°C.
Primary drying was performed for 10 minutes. Next, apply the top coat paint to the primed painted board using air spray so that the dry film thickness is approximately 5 μm.
Secondary drying was performed at ℃ for 3 hours. This was immersed in an ammonium phosphate aqueous solution (2.5% primary ammonium phosphate, 2.5% secondary ammonium phosphate, PH 6.5) at 30°C for 8 hours, then further immersed in water for 12 hours, and then washed with water at 80°C. It was dried. (3) Filling of fine cracks On the painted board obtained in (2) above, apply the above filling coating solution using a rubber spatula, and the acrylic transparent paint adheres to the top surface of the coating film with the rubber spatula. was removed and then dried at room temperature for 24 hours. Example 1B On the painted board obtained in Example 1A (2),
Coating liquid X-12-2200 (product name,
(manufactured by Shin-Etsu Chemical Co., Ltd.) was applied by air spray at a rate of 0.01 ml/cm ² and allowed to dry at room temperature for 1 hour. Thereafter, it was further dried at 110°C for 2 hours. Examples 2A, 2B (1) Preparation of paints The preparations of the undercoat paint and topcoat paint in Example 1A were changed as shown below, and the paints were prepared in the same manner. (i) Preparation of undercoating paint Sodium silicate aqueous solution (40% liquid)
60 [Parts by weight] Potassium silicate aqueous solution (30% liquid)
40 〃 Aluminum polyphosphate 10 〃 Zinc oxide 10 〃 Silica powder 50 〃 Potassium pyrophosphate 2 〃 Aerosil 0.5 〃 Red iron 10 〃 Water 80 〃 Surfactant (5% liquid) 1 〃 Antifoaming agent (5% liquid) 1 〃 ( ii) Preparation of top coating paint Sodium silicate aqueous solution (40% liquid)
100 [Parts by weight] Red iron 10 Potassium pyrophosphate 0.5 Water 100 Surfactant (5% liquid) 1 Antifoaming agent (5% liquid) 1 (2) Painting Apply the undercoat paint to an asbestos slate board (thickness 3mm) by air spray to a dry film thickness of approximately 40 μm, and after leaving it in the air for 30 minutes, apply a top coat to the primed painted board by air spraying to a dry film thickness of approximately 10 μm. It was coated so that it was evenly coated and dried at 120°C for 5 hours.
This was added in an aqueous ammonium phosphate solution at 40℃ (5
Ammonia gas was blown into the phosphoric acid solution to adjust the pH value to 7.0. ) for 6 hours, further immersed in 0.5% saline solution for 5 hours, and then washed with water.
Air dried. (3) Filling of fine cracks On the two obtained painted plates, (a) the acrylic transparent paint coating liquid used in (3) of Example 1A was used (Example 2A), and the other (b) Example
Coating liquid X-12-2200 used in Example 1B (Example 2B) was used to fill fine cracks in the coating according to the procedures in Example 1A (3) and Example 1B, respectively. Examples 3A, 3B (1) Preparation of paints The preparations of the undercoat paint and topcoat paint in Example 1A were changed as shown below, and the paints were prepared in the same manner. (i) Preparation of undercoating paint Sodium silicate aqueous solution (40% liquid)
65 [parts by weight] Potassium silicate aqueous solution (30% liquid)
20 〃 Lithium silicate aqueous solution (25% liquid)
15 〃 Magnesium polyphosphate 15 〃 Zinc polyphosphate 10 〃 Alumina powder 40 〃 Synthetic mica 10 〃 Sodium pyrophosphate 2 〃 Cobalt blue 10 〃 Water 90 〃 Surfactant (5% liquid) 1 〃 Antifoaming agent (5% liquid) 1〃 The top coat paint was prepared by mixing and stirring using the formulation shown below. (ii) Preparation of top coating paint Sodium silicate aqueous solution (40% liquid)
50 [parts by weight] Potassium silicate aqueous solution (30% liquid)
50 [parts by weight] Water 100 〃 Surfactant (5% liquid) 1 〃 (2) Painting Apply the undercoat paint to a calcium silicate plate (4 mm thick)
Apply air spray to a dry film thickness of approximately 50 μm, leave it in the air for 10 minutes, and then apply air spray to a painted board that has been primed with top coat paint to a dry film thickness of approximately 10 μm. It was painted and dried at 130℃ for 90 minutes. This was added to an ammonium phosphate aqueous solution at 30°C (concentrated ammonia water was added to a 5% phosphoric acid solution to bring the pH value to 8.0.
Adjusted as follows. ) for 8 hours, then soak for 1 hour.
% saline solution for 4 hours, washed with water, and dried in the air. (3) Filling of fine cracks Fine cracks were filled in the same manner as in (3) of Example 1A (Example 3A) or in the same manner as in Example 1B (Example 3B). Example 4 Instead of the ammonium phosphate aqueous solution in Example 1A, ammonia gas was blown into a 5% by weight aqueous solution of (1) ammonium sulfate, (2) ammonium nitrate, (3) ammonium chloride, or (4) ammonium acetate to adjust the PH value. Example 1: Using 30°C aqueous solution adjusted to temperature 7, immersion was carried out for 10 hours, and the other conditions were the same.
Repeated step 1A. The coating solution of Example 1B was similarly applied to the resulting coating film to fill in fine cracks. Example 5 The undercoat paint of Example 1A was applied to a calcium silicate plate (thickness: 3 mm) by air spray in two parts to a dry film thickness of about 50 μm, and dried at 130°C for 3 hours. , immersed in the 30°C aqueous ammonium phosphate solution used in Example 1A for 8 hours, further immersed in water for 12 hours, washed with water, and dried at 80°C for 10 minutes. Next, the top coat used in Example 1A was applied to the undercoated and chemically treated painted board by air spraying to a dry film thickness of about 5 μm, and dried at 130°C for 1 hour. .
This was immersed in the above-mentioned aqueous ammonium phosphate solution at 30°C for 2 hours, further immersed in water for 12 hours, washed with water, and dried at 80°C. Examples are shown on the resulting coating film.
Coating solution 1B was applied in the same manner to fill fine cracks. Example 6 A rough glass plate with a thickness of approximately 3 mm was spray-coated with a top coat of Example 2A to a thickness of 20 μm in two separate coats with 5 parts by weight of zinc oxide added and stirred. The following is the same as Example 1A,
Drying, ammonium phosphate aqueous solution treatment, immersion in water, and drying were performed. The coating solution of Example 1B was similarly applied to the coating film of the obtained painted object to fill in fine cracks. Evaluation Examples 1A, 1B, 2A, 2B, 3A, 3B,
The crack-filled coatings obtained in Examples 4, 5 and 6 were tested for water permeability and stain resistance. As a result, water permeability and stain resistance were both essentially perfect with no abnormalities. For comparison, in each of the above examples, the water permeability and stain resistance of the coating film before application of the final treatment coating solution were similarly tested.
As for water permeability, a slight amount of water permeation was observed, and as for stain resistance, a slight amount of water permeation was observed after staining. For your reference,
Performance of coating film before application of filling coating liquid (Patent application 1983-
206675) are shown in the following table.

【table】

[Table] In the above, the mark ◯ indicates that it is practically satisfactory, and the blank indicates that the measurement was omitted. Therefore, a coating treated with crack filling according to the present invention corresponds to a mark ◎ in the table above, which is substantially perfect, at least in terms of water permeability and stain resistance. The test method for the above coating film performance is as follows. (1) Water permeability: A glass tube is placed on the surface of the coating film, and a 25cm
Pour water at 20℃ to the height of , leave it for 24 hours, then observe the back side of the board. (2) Accelerated weathering: Observe the surface after 500 hours of irradiation with a sunshine weather meter. (3) Boiling water resistance: Observe the surface after immersing in boiling water at 100℃ for 5 hours. (4) Efflorescence resistance: One cycle consists of leaving the back side of the sample in a humid environment for one day and then air drying it for one day. After 10 cycles, the front side was observed. (5) Stain resistance: Apply Vaseline mixed with 10% carbon black, leave it for 24 hours, wipe it off with gauze soaked in soapy water, and observe the surface. (6) Gloss: Visual inspection (7) Acid resistance: Observe the surface after applying 10% HCl aqueous solution for 15 minutes. (8) Against alkalinity: Observe the surface after applying 10% NaOH aqueous solution for 15 minutes. (9) Adhesion: Goban test (100 pieces of 2 x 2 mm) (10) Maximum crack width: Measured using an electron microscope after being left in the air for 3 months.

Claims (1)

[Claims] 1. A water-soluble alkali metal silicate-based aqueous solution paint for undercoat containing powder solids is applied onto a mineral substrate, dried appropriately, and then the undercoat paint is Also, a water-soluble alkali metal silicate-based aqueous solution paint for topcoating with a substantially small to zero powder solid content is applied to a suitably dried paint film with a pH value of 3.5 to 10.0. It is characterized by applying an acid/ammonium salt-based aqueous solution, washing with water and drying, and applying a curable filling coating liquid to the resulting coating film having fine cracks to fill the fine cracks in the coating film. A method for forming an inorganic coating film. 2. The filling coating solution according to claim 1, wherein the filling coating liquid consists essentially of a curable, non-efflorescent inorganic and/or organic material, or a solution or fine particle suspension containing these materials. How to form a coating film. 3 The above filling coating liquid may be organic paint, liquid resin,
The method for forming a coating film according to claim 2, which is a mixture of one or more selected from silica sol, metal alkoxide hydrolyzate, and polysiloxane, or a solution or suspension containing them. 4. The method of forming a coating film according to any one of claims 1 to 3, wherein at least the undercoating coating material of the coating material contains an effective amount of a curing agent. 5 The PH value of the above acid/ammonium salt aqueous solution is 4.
9. The method for forming a coating film according to any one of claims 1 to 4. 6. Claims 1 to 5, wherein the amount of the powder solid content contained in the undercoating paint ranges from 20% by weight or more to the amount retained as a paint in the silicate aqueous solution vehicle. A method for forming any of the coating films. 7. The method of forming a coating film according to any one of claims 1 to 6, wherein a dilute aqueous solution of a strong base-strong acid salt is used for washing with water. 8. Apply a water-soluble alkali metal silicate-based aqueous solution paint for undercoating containing powder solids onto the mineral base material, dry it appropriately, and apply an acid/ammonium salt-based aqueous solution with a pH value of 3.0 to 10.0. applied, washed with water, dried, and then applied with a water-soluble alkali metal silicate topcoat having substantially less to no powder solids content than the basecoat. The pH value of the properly dried paint film
Apply a 3.5 to 10.0 acid/ammonium salt aqueous solution, wash with water, and dry. Apply a curable filling coating liquid to the resulting coating film with fine cracks to fill the fine cracks in the coating film. A method for forming an inorganic coating film, characterized by: 9. The filling coating solution according to claim 8, wherein the filling coating liquid consists essentially of a curable, non-efflorescent inorganic and/or organic material, or a solution or fine particle suspension containing these materials. How to form a coating film. 10 A patent claim in which the filling coating liquid is one or a mixture of two or more selected from organic paint, liquid resin, silica sol, metal alkoxide hydrolyzate, and polysiloxane, or a solution or suspension containing them. The method for forming a coating film according to item 9. 11 Claims 8 to 1, wherein at least the undercoating paint of the paint contains an effective amount of a curing agent.
The method for forming a coating film according to any of item 0. 12 Claims 8 to 11, wherein the acid/ammonium salt aqueous solution has a PH value in the range of 4 to 9.
A method for forming a coating film according to any of the above. 13. Claims 8 to 12, wherein the amount of powder solids contained in the undercoating paint ranges from 20% by weight or more to the amount retained as a paint in the silicate aqueous solution vehicle. A method for forming any of the coating films. 14. The method for forming a coating film according to any one of claims 8 to 13, wherein a dilute aqueous solution of a strong base-strong acid salt is used for washing with water. 15. Applying a water-soluble alkali metal silicate-based aqueous paint having a powder solids content of less than 30% by weight to substantially zero on mineral substrates, and in particular on substantially non-porous substrates. After at least one coat of paint, which consists of moderate drying, the PH value
A 3.5 to 10.0 acid/ammonium salt aqueous solution is applied, washed with water and dried, and then a curable filling coating liquid is applied to the resulting coating film having fine cracks to eliminate the fine cracks in the coating film. A method for forming an inorganic coating film characterized by filling. 16. The method according to claim 15, wherein the filling coating liquid consists essentially of a curable non-efflorescent inorganic and/or organic material, or a solution or fine particle suspension containing these materials. How to form a coating film. 17 A patent claim in which the filling coating liquid is one or a mixture of one or more selected from organic paint, liquid resin, silica sol, metal alkoxide hydrolyzate, and polysiloxane, or a solution or suspension containing them. The method for forming a coating film according to item 16. 18. The method of forming a coating film according to any one of claims 15 to 17, wherein the coating material contains an effective amount of a curing agent. 19 Claims 15 to 1, wherein the acid/ammonium salt aqueous solution has a PH value in the range of 4 to 9.
The method for forming a coating film according to any of Item 8. 20. The method for forming a coating film according to any one of claims 15 to 19, wherein a dilute aqueous solution of a strong base-strong acid salt is used for washing with water.