JPH0673328A - Formation of coating film - Google Patents

Abstract

PURPOSE:To form a coating film of good adhesion to a material, especially a building material by using an emulsion coating material containing a specified acrylic resin emulsion containing an organic solvent as a vehicle. CONSTITUTION:An emulsion coating material containing, as a vehicle resin, an acrylic resin emulsion which can give a coating film of an elongation of 200% or below and a tensile strength of 40kg/cm<2> or above and which is prepared by emulsifying 100 pts.wt. solution (A) of a polymer, obtained by polymerizing 100 pts.wt. monomer mixture comprising an alpha,beta-ethylenically unsaturated carboxylic acid and/or a 2-8C alkyl acrylate (a), methyl acrylate (b) and another copolymerizable vinyl monomer (c) in a weight ratio (a)/(b)/(c) of (1-14)/(0-41)/(45-99) in 80-125 pts.wt. organic solvent and having an Sp of 8.8-11, a Tg of 30-100 deg.C and a number-average molecular weight of 20000-100000, and 1-4 pts.wt. surfactant (B) in 20-50 pts.wt. deionized water is directly applied to an inorganic substrate and dried.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a coating film, and more particularly to a method for forming a coating film which adheres to a material with an emulsion coating containing a specific acrylic resin emulsion containing an organic solvent as a resin vehicle.

[0002]

2. Description of the Related Art In coating building materials such as mortar, concrete, and slate, a sealer or primer is usually used for the purpose of adjusting the groundwork and improving the adhesion to both the material and the topcoat. Then, a coating material for waterproofing, and then a topcoat for eliminating tackiness of the coating film and improving stain resistance are sequentially applied. However, such a method requires a large number of paints, resulting in complicated man-hours and steps. Therefore, reduce the necessary coating layer as much as possible,
Many proposals have been made to make economical waterproofing possible. Among them, one of the technologies to be noticed is the invention described in JP-A-52-136229. In the present invention, α, β-monoethylenically unsaturated carboxylic acid 0.1 to
The boiling point is 100 parts by weight with respect to 100 parts by weight of a monomer mixture consisting of 10% by weight, an alkyl acrylate having 2 to 10 carbon atoms, 20 to 99.5% by weight, and 70% by weight or less of another copolymerizable vinyl monomer. 10 to 150 parts by weight of inorganic filler and 1 to 50 short fibers per 100 parts by weight of a synthetic resin emulsion obtained by emulsion polymerization of a mixture of 3 to 50 parts by weight of an organic solvent having a temperature of not less than 0 ° C and / or a plasticizer. By applying a coating film waterproofing composition having a viscosity of 500 cps or more including parts by weight, the coating film surface does not have tackiness even without a topcoat, the strength and elongation balance can be balanced, the waterproofness and the beauty finish can be achieved. It is intended to provide a waterproof layer that is effective. No mention of the primer layer for the material,
In the examples, the above composition is merely spray-coated on a plate to evaluate the coating film. However, in the patent, as a prior art using a synthetic resin emulsion,
A synthetic resin solution or emulsion is applied to the material to form a primer layer, and a waterproof coating composition based on the synthetic resin emulsion is applied on the material to further eliminate the surface tackiness of the film. There was a technique to apply and finish a high top coat, an invention was made to improve the drawbacks of the conventional waterproofing enforcement method that requires the formation of this top coat layer, etc. The emphasis is on, and the explicit reference to the primer is avoided. However, such a primer layer is necessary for actual waterproofing. In fact, if the coating film has an elongation of 300 to 400% and a strength of 25 to 38 kg / cm ² shown in the same patent, sufficient adhesion to the material is obtained. However, the present inventors have found that the primer layer is essential for the improvement purpose.

On the other hand, it is also known to use an emulsion obtained by emulsifying a solution of an acrylic resin in an organic solvent in water with a surfactant as a coating material. For example, JP-A-53-24386 discloses aromatic compounds. Vinyl monomer 15-6
0% by weight, long-chain acrylate-based monomer 25 to 50
% By weight, alkoxyalkyl (meth) acrylamide 3
-30% by weight, and unsaturated carboxylic acid type monomer 0-1
Tg-6 obtained by copolymerizing 2% by weight in an organic solvent
C. to 30.degree. C. A copolymer solution is obtained by emulsifying in water with 0.25 to 3% by weight of a surfactant based on the weight of the copolymer and adjusting the pH to 6.5 to 10. An aqueous coating composition consisting of a hydrophobic copolymer is shown. However, the polymer of such an emulsion emulsion has a low Tg value,
The polymer solution actually produced is an acrylic oligomer having a high non-volatile concentration of about 70% and a relatively low number average molecular weight. This patent specification shows that this water-based paint has the same satisfactory performance as a solvent-based paint of a conventional epoxy resin or vinyl chloride-vinyl acetate copolymer as a lining agent for metal containers for food, beer and beverages. However, it does not give any suggestion as to whether it can be applied to building materials.

The present inventors have in fact found that the above-mentioned water-based paint is completely unsatisfactory with respect to building materials. As described above, any of the conventionally proposed emulsion paints containing an organic solvent has poor material adhesion, requires a primer layer, and is required to have a top coat in terms of performance and beauty finish. Was there.

[0005]

Therefore, not only a top coat, but also a sealer and a primer layer are not required, and a coating film having good adhesion to a building material is formed. If it is possible, it is economically extremely advantageous in combination with the number of steps and the simplification of the process. In addition, it is desired to form a coating film with a glossy feeling from the viewpoint of beauty, and it is possible to meet such a request. It is an object of the present invention.

[0006]

According to the present invention, the above objects are (a) (a) an α, β-ethylenically unsaturated carboxylic acid and / or an alkyl acrylate having 2 to 8 carbon atoms,
(B) methyl methacrylate, and (c) other copolymerizable vinyl monomer, wherein (a) / (b) / (c) is 1 to
Sp 8.8-11, Tg30 obtained by polymerizing 100 parts by weight of the polymerizable monomer having a ratio of 14 / 0-41 / 45-99 (weight ratio) in 80-125 parts by weight of an organic solvent.
To 100 ° C., number average molecular weight of 20,000 to 100,000
100 parts by weight of the polymer solution of 0, and (b) the surfactant 1 to
4 parts by weight and (c) 20 to 50 parts by weight of deionized water were emulsified to obtain a coating film elongation of 200% or less, tensile strength 4
This can be achieved by directly coating and drying an inorganic paint with an emulsion coating containing a synthetic resin emulsion capable of giving a coating film of 0 kg / cm ² or more as a resin vehicle.

The synthetic resin emulsion used in the present invention comprises (a) (a) an α, β-ethylenically unsaturated carboxylic acid and / or an alkyl acrylate having 2 to 8 carbon atoms,
(B) methyl methacrylate, and (c) other copolymerizable vinyl monomer, wherein (a) / (b) / (c) is 1 to
Sp of 8.8 to 11, which is obtained by polymerizing 100 parts by weight of the polymerizable monomer having a ratio of 14/0 to 41/45 to 99 (weight ratio) in 80 to 125 parts by weight of an organic solvent, Tg is 30 to 100 ° C., number average molecular weight is 20,000 to 10
It is produced by stirring and mixing 100 parts by weight of a solution of 20,000 polymer with (b) 1 to 4 parts by weight of a surfactant and (c) 20 to 50 parts by weight of deionized water to emulsify the coating film. It has a characteristic that a coating film having a rate of 200% or less and a tensile strength of 40 kg / cm ² or more can be provided.

The glass transition temperature (Tg) of the acrylic resin can be controlled by changing the type and amount of the α, β-ethylenically unsaturated monomer of the constituent monomer, but usually T
The lower the g, the better the elongation at low temperature, and the higher the Tg, the harder the film becomes, and the higher the minimum film forming temperature (MFT) becomes.
Acrylic resins with Tg values well below ° C are used.

As a result of examining the adhesiveness of materials, the inventors of the present invention have found that the tensile strength and elongation rate are important. If the tensile strength is low, a cohesive failure will occur in the coating film, resulting in a brittle coating film, and if the elongation ratio is too high. It is easy to peel off from the material side, and the resin T
g and number average molecular weight also play an important role, and Tg is 3
If the temperature is lower than 0 ° C, the coating film is soft and the cohesive force is low, so that the adhesive force is reduced, and even if the number average molecular weight is less than 20,000, the cohesive force is low and the adhesive force is lowered. It was found that the coating properties such as properties are not preferable.
Further, it is considered that a resin having Tg of 30 to 100 ° C. usually has low elongation and is too hard, and MFT is too high to form a film. However, by containing an organic solvent, a film forming property is imparted, and a material is used. The present invention has been completed based on the knowledge that a uniform film can be formed due to the effect of penetrating into the skin.

That is, the resin of the synthetic resin emulsion of the present invention has a Tg in the range of 30 ° to 100 ° C and a number average molecular weight of 20,000 or more. A more preferable range is Tg of 50 ° to 80 ° C. and a number average molecular weight of about 3,0.
It is 00 or more. Despite this high Tg value,
Since the solvent has a film-forming aid effect, it has a good film-forming property and also has an effect of penetrating into the material, and it is possible to provide a coating film excellent in stain resistance, adhesion and initial water resistance. Also, since the degree of polymerization is high,
Strong film, excellent film cohesion, material adhesion, water resistance,
Good weather resistance. Furthermore, such a resin emulsion has a coating film elongation of 200% or less, preferably 100% or less, and a tensile strength of 40 kg / cm ² or more, preferably 50 k.
It has a feature that it can give a coating film of g / cm ² or more. These characteristics are achieved by making a high-molecular-weight resin having a high Tg in a solvent-containing form, and give a very good balance of strength and elongation to building materials as well as material adhesion. .

Component (a) as a monomer constituting the synthetic resin emulsion used in the present invention is α, β-
It is an ethylenically unsaturated carboxylic acid and / or an alkyl acrylate having 2 to 8 carbon atoms. Examples of the α, β-ethylenically unsaturated carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, maleic anhydride, fumaric acid and the like. Carbon number 2-8
Examples of the alkyl acrylate include ethyl acrylate, propyl acrylate, butyl acrylate, ethylhexyl acrylate and the like. Ingredient (b) is methylmethacrylate.

The component (c) is a vinyl monomer copolymerizable with the components (a) and (b), and the following monomers can be used alone or in combination. 1) Hydroxyl group-containing monomer For example, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl. Methacrylate, allyl alcohol, methallyl alcohol, etc. 2) Polymerizable amide, such as acrylic acid amide, methacrylic acid amide, etc. 3) Polymerizable nitrile, such as acrylonitrile, methacrylonitrile, etc. 4) Alkyl meta having 2 or more carbon atoms Acrylate such as ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, etc. 5) Polymerizable aromatic compound such as styrene, α-methylstyrene, vinyltoluene, t- Butyl styrene, etc. 6) α-olefins such as ethylene, Propylene, etc. 7) vinyl compounds such as vinyl acetate, vinyl propionate, etc. 8) diene compounds such as butadiene, isoprene they are appropriately selected to sell the desired Tg value.

The ratio of (a), (b) and (c) of the present invention must be 1 to 14/0 to 41/45 to 99 by weight ratio, and if the component (a) is less than 1, the emulsion is not. Stability decreases. If it exceeds 14, water resistance and weather resistance are deteriorated. If (b) exceeds 41, the adhesiveness and water resistance will deteriorate. When (c) is less than 45, the water resistance is reduced. If it exceeds 99, the stability of the emulsion decreases.

Further, since the synthetic resin solution is prepared by an emulsion method in which it is emulsified in water, the solubility parameter (Sp) value of the acrylic resin is limited to the range of 8.8 to 11, and the solubility is further exceeded. It becomes too large to obtain the desired emulsion. Therefore, the above-mentioned monomers are also appropriately selected so as to give a desired Sp value and used alone or in any combination. The solubility parameter (δsp) of the resin is K.K. W. SUH, J. M. CORBET
T: Journal of Applied Polymer Science 12,2359 ('6
It can be calculated from Equation 1 shown in 8). In the formula 1, ml is a low SP solvent; mh is a high SP solvent; δ is a solubility parameter; V is a molecular volume at the cloud point.

[0015]

[Equation 1]

The organic solvent may be any solvent that can serve as a solvent for acrylic resins, such as aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as mineral spirits, ketones, alcohols and esters. A plasticizer and a softening agent having a boiling point of around 300 ° C. or higher, which is shown in a solvent manual (published by Maki Shoten), can also be used as a solvent. In the present invention, the above-mentioned ethylenically unsaturated monomer is polymerized by a usual method using a polymerization initiator in an organic solvent, but the weight ratio of the monomer to the organic solvent is 100, with respect to the former 100.
The latter is selected in the range of 80 to 125. This is to adjust the molecular weight of the polymer. If the latter is less than 80, a uniform polymer solution cannot be obtained, and if it exceeds 125, a uniform polymer solution can be obtained, but the molecular weight becomes low and the adhesion is impaired. It is a thing.

In the present invention, a solution of the thus obtained polymer having Sp 8.8 to 11, Tg of 30 to 100 ° C. and a number average molecular weight of 20,000 to 100,000 is then added with a surfactant and The emulsion is emulsified by a post-emulsification technique using deionized water. The surfactant is of a usual type, but in particular, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, Alkyl ethers such as polyoxyethylene tridecyl ether, polyoxyethylene alkyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, etc.
Ter-type nonionic activator; polyoxyethylene laure
Alkyl ester type nonionic surfactants such as polyoxyethylene oleate and polyoxyethylene stearate; nonionic surface active agents of sorbitan derivatives such as sorbitan laurate and polyoxyethylene sorbitan oleate Agents; anionic surfactants such as sodium dodecylbenzene sulfonate and sodium polyoxyethylene alkylphenyl ether sulfate are preferably used in any combination.

The proportions of the polymer solution, the surfactant and the deionized water are appropriately selected according to the usual emulsification method, but since they are used as the resin vehicle of the aqueous paint, the weight ratio is 10%.
It is desirable to set it in the range of 0: 1 to 4:20 to 50.
The coating composition containing the emulsion emulsion thus obtained as a resin vehicle has good material adhesion, so that it can be used as a clear coating as it is, or as a coating for one coat by adding a pigment and a filler to this. use.

Usable pigments are, for example, titanium dioxide rutile type, anatase type, inorganic pigments such as lithopone, iron oxide, chromium oxide, etc., and other conventional pigments for paints such as organic pigments. , Mica,
Ordinary fillers for paints such as calcium carbonate and silica are preferably used. As described above, the resin of the present invention has excellent material adhesion, but when pigments and fillers are added, maintaining the pigment volume concentration (PVC) at 35% or less has a residual effect on adhesion. It has been shown and has also been found to be particularly preferred. Also, if desired, it is possible to add any thickening agent having a thixotropic effect, such as polyethylene oxide, amide, acrylic having three-dimensional cross-linking, or silica.

As described above, since the strength is maintained without being largely affected by the amount of the inorganic filler, the PVC can be maintained at a low value of 35% or less, a glossy paint can be formed, and desired coating strength can be maintained. Sent. In the present invention, the article to be coated is an architectural material, for example, an inorganic material such as mortar, concrete, or slate. It can also be directly applied to a paint coating surface, for example, a cement-based inorganic paint coating surface, or an acrylic resin, urethane resin, or other organic coating surface. The coating film forming method of the present invention can be performed by a known method. That is, air spray coating, airless spray coating, roll coating
Any method such as color coating may be used. In the present invention, the direct application means that the specific emulsion paint is directly applied to the material to be coated without the need for a sealer and a primer which are usually used for improving adhesion and preventing foaming. The coating amount depends on the solid content and specific gravity of the coating composition, but since it can form a uniform thickness and form a waterproof layer, a coating viscosity of 50 to 250 ps and about 0.5 to 1.0 kg / m ² are suitable. . At this time, it is possible to form a strong coating film having excellent water resistance, weather resistance, stain resistance, and adhesion to an object to be coated, even with only this base coat layer. Since the coating composition can be applied again after the drying of the coating layer, it is possible to form a patterned coating film. The pattern coating film is preferably a spray gun such as a tile gun or a resin gun for the ball-blowing pattern and the uneven pattern. The coating amount depends on the solid content and specific gravity of the coating composition, but the coating viscosity is 200 to 400 ps. And about 0.4
Appropriately 0.8 kg / m ² . Further, the corrugated pattern is preferably a porous roller, a wool roller, or the like, and the standard of the coating amount at that time depends on the solid content of the coating component and the specific gravity, but the coating viscosity is 100 to 250 ps. 0.4-0.8kg / m
² is appropriate. As described above, the present invention does not require a sealer, a primer, or a top coat with respect to the building material, and one coat is excellent in water resistance, weather resistance, chemical resistance, etc. A strong coating film with excellent stain resistance can be provided, and it is possible to form a coating film with satisfactory material adhesion. The present invention will be described below with reference to examples. Unless stated otherwise, parts and percentages are by weight.

[0021]

[Examples and Comparative Examples]

Reference Example 1 A thermometer, a stirrer, a nitrogen introduction tube,
Equipped with dropping funnel, charged with 400 g of xylene, 85 ° C
Keep the internal temperature at. Methyl methacrylate 405 g, isobutyl methacrylate 583 g, methacrylic acid 12
g was evenly mixed, 7 g of t-butylperoxy-2-ethylhexanoate was further added, and the mixed solution was added dropwise over 3 hours while blowing nitrogen, and polymerization was carried out at 85 ° C. with stirring. After dripping, 800 g of xylene is added to
It dripped over time. Then, the reaction was further performed at 85 ° C. for 2 hours. Nonvolatile matter 45.4%, number average molecular weight 4
2,000, Tg (calculated value) = 70 ° C., Sp value 10.0
To obtain a colorless and transparent copolymer liquid (A).

Reference Examples 2 to 4, 6 The same procedure as in Reference Example 1 was carried out. The composition of the monomer and the organic solvent was changed as shown in Table 1, and the colorless and transparent copolymer liquids (B), (C), (D) and (F) were obtained respectively. Reference Example 5 The procedure of Reference Example 1 was repeated to prepare the amount of the polymerization initiator t-butylperoxy-2-ethylhexanoate,
A colorless and transparent copolymer liquid (E) was obtained.

[0023]

[Table 1]

Production Example 1 Preparation of Emulsion Emulsion- (1) 1000 g of copolymer liquid (A) and nonionic activator Newc.
While stirring 30 g of ol1710 (manufactured by Nippon Emulsifier Co., Ltd.) with a disperser, 300 g of ion-exchanged water was gradually added to form an emulsion. Ammonia water is added and the pH =
8 to obtain an emulsion emulsion- (1). Nonvolatile content 36%, emulsion average particle size 1.0μ

Production Examples 2 to 6 Emulsion Emulsions- (2) to (6) Emulsion Emulsions- (2) to (6) were obtained in the same manner as in the preparation of Emulsion Emulsions- (1). The compounding amount, the non-volatile content, and the emulsion average particle size are shown in Table 2.

Preparation of dispersion paste SMA-1440 (manufactured by Arco Chemical Co., styrene-maleic acid ester dispersant) 15 parts, titanium dioxide 100
Part, calcium carbonate (made by Luminous Maruo Calcium Co.) 1
00 parts and 70 parts of water were mixed and dispersed to obtain a dispersion paste.

[0027]

[Table 2]

Example 1 26 parts of dispersion paste, emulsion emulsion- (1) 100
Parts, 1 part antifoaming agent and 2 parts thickener were mixed and stirred to obtain a coating composition. This coating composition has PVC = 13, viscosity 300
It was P (poise). The coating composition was adjusted to 180 PS (poise), and the dry film thickness was 50 with a spray gun on the plate.
Coating was performed so that the thickness became 0 μ, and a coating film was formed. After being dried at room temperature for 2 weeks, the gloss was 70 at 60 degree gloss, the elongation rate was 5%, the tensile strength was 70 kg / cm ² , and the adhesion was 20 kg / cm ² as measured by an adhesion tester. Further, the peeling adhesion of this coating film was peeled from the material and the adhesion was good. Further, the coating film hardness was HB in terms of pencil hardness. Further, this coating composition was used as a base coat, and after drying for about one day, the coating composition adjusted to 240 PS was coated thereon with a tile gun at 0.6 kg / m ² to form an uneven pattern coating film. . Dry this at room temperature for 2 weeks, then at 20 ℃
After immersion in water for 1 week, the state of the coating film was judged by the ASTM method, and no swelling of the coating film was observed.

Examples 2 to 4 A coating composition was obtained in the same manner as in Example 1 to form a coating film. The results of Table 3 were obtained for the blending and evaluation of physical properties.

Comparative Examples 1 to 3 A coating composition was obtained in the same manner as in Example 1 to form a coating film. The results of Table 3 were obtained for the blending and evaluation of physical properties.

Comparative Example 4 As an example of a commercially available synthetic resin emulsion-based multi-layer finish coating material, “Diamond E tile main material (manufactured by Kowa Chemical Industry Co., Ltd.)” was adjusted to 150 PS (poise) to prepare an acrylic sheet. Insert the liner and spray on the plate with a spray gun to dry film thickness 500μ
Was coated to form a coating film, and the physical properties were evaluated in the same manner as in Example 1. Furthermore, 210PS on this coating
"Diamond E tile main material" adjusted to 1. with a tile gun.
The coating was applied at 0 kg / m ² to form an uneven coating film. As for the physical property evaluation, the results shown in Table 3 were obtained.

Comparative Example 5 As an example of a commercially available synthetic resin emulsion single layer elastic finishing material, “Ales Rubber Tex (Kansai Paint Co., Ltd.)” was adjusted to 160 PS and a salt rubber sealer was put in to give a sheet. The plate was coated with a porous roller to a dry film thickness of 400 μm to form a coating film, and the physical properties were evaluated in the same manner as in Example 1. Furthermore, "Ares rubber tile" adjusted to 60 PS on this coating film is 0.25 with a medium wool roller.
It was applied with kg / m ² to form a rippled coating film. As for the physical property evaluation, the results shown in Table 3 were obtained.

The coating film was tested by the following method. 1. Measurement of Elongation Rate and Tensile Strength A coating material was applied to 2 mm in accordance with JIS A 6910, dried at room temperature for 14 days, and then molded into a dumbbell-shaped No. 2 shape to give a test piece. 2. Measurement of Adhesion Force A coating material was applied to a plate by a doctor blade to a thickness of 2 mm, dried at room temperature for 2 weeks, and then the adhesion force was measured with an adhesion tester. 3. Peeling Adhesion The coating film was cut into a width of 5 mm and a length of 10 mm, and the degree of peeling of the coating film was measured with a cutter, and evaluated as follows. ○… Peeling from the material ×… Peeling at the interface between the material and the coating film 4. Pencil hardness A coating of 2 mm was applied on a plate with a doctor blade and dried at room temperature for 2 weeks, and then JIS-K-5400-8-
It measured according to the 4th method. 5. A test piece on which a base coat was formed on a water resistant plate and a pattern coating film was further formed was dried at room temperature for 2 weeks and then placed in water at 20 ° C. for 7 weeks.
After being immersed for a day, the state of the coating film after being taken out was measured by the ASTM method. However, Comparative Examples 4 to 5 were applied under the conditions described in Comparative Example.

[0034]

[Table 3]

[0035]

As described above, the coating film formed according to the present invention does not require a primer or a top coat and is excellent in water resistance, weather resistance and stain resistance with one type of coating material, and can be applied to an object to be coated. The adhesiveness is excellent, and as a result, the coating film can protect the article to be coated and maintain the appearance. In addition, it is possible to use roller coating, spray coating, brush coating, etc. by diluting with water to adjust the viscosity, and it becomes a base conditioning material and a building interior / exterior finishing material. Finishing and multi-layer finishing are now possible.

Front page continuation (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area C09D 5/02 PPU

Claims (1)

[Claims] 1. (a) (a) α, β-ethylenically unsaturated carboxylic acid and / or alkyl acrylate having 2 to 8 carbon atoms, (b) methyl methacrylate, and (c). Other copolymerizable vinyl monomers (a) / (b) / (c)
Is obtained by polymerizing 100 parts by weight of a polymerizable monomer having a ratio of 1 to 14/0 to 41/45 to 99 (weight ratio) in 80 to 125 parts by weight of an organic solvent, Sp 8.8 to 11 , T
g 30 to 100 ° C., number average molecular weight 20,000 to 10
100 parts by weight of a polymer solution of 20,000, (b) 1 to 4 parts by weight of a surfactant, and (c) 20 to 50 parts by weight of deionized water are emulsified, a coating film elongation rate of 200% or less, a tensile strength of 40 kg. / Emulsion paint containing acrylic resin emulsion as a resin vehicle that can give coating film of at least ₂ cm2 / cm2 is directly applied to inorganic materials.
A method for forming a coating film, which comprises drying.