JPH10245505A - Coating film resistant to rain flow mark, coating composition, method for forming coating film and coated article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating film resisting well to rain flow marks and having excellent durability, abrasion resistance, chemical resistance and weathering resistance, a coating composition and a method for forming a coating film. SOLUTION: This film comprises an inorganic binder composition (A) and has a dynamic reversed tension (Tr) of 47dyn/cm or above for water. Composition A comprises at least one member selected from the group consisting of an organoalkoxysilane compound, a partial hydrolyzate of the organoalkoxysilane compound, a tetrafunctional alkoxysilane compound, a partial hydrolysis condensate of the tetrafunctional alkoxysilane compound and a siloxane polymer and at least one member selected from the group consisting of an alkoxysilyl-containing vinyl polymer and a partial hydrolysis condensate obtained by hydrolyzing an organosilicon compound and condensing the hydrolyzate and having a degree of hydrolysis of below 100% and having mol.wt. of 400-below 10,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating film, a coating composition, and a method for forming a coating film having resistance to rain dripping contamination.

[0002]

2. Description of the Related Art The surfaces of buildings, displays, guard fences, machinery and the like installed outdoors are covered with a coating film for decoration and protection. Such coatings are required to have properties that can withstand outdoor use, such as weather resistance, impact resistance, acid resistance, and water resistance. Is also required.

[0003] The above-mentioned stain resistance includes stain resistance against contamination such as oily marker contamination, carbon contamination, oil contamination, food contamination, and raindrop contamination. Above all, the stain resistance against raindrop contamination is as follows. It is one of the important properties of the coatings that coat buildings. Rain dripping is a phenomenon in which rain on a painted plate installed perpendicularly to the ground or a painted plate installed at an angle becomes water droplets and flows down the surface of the painted plate containing the pollutant, thereby causing the contaminant to fall. Is the contamination that occurs by adhering to the painted plate surface along the flow of water droplets,
Also known as rain streak pollution.

[0004] In general, buildings and displays, which are installed outdoors, are hardly washed, so that the coating films used for them are continuously resistant to the above-mentioned raindrops for a long period of time. Is required. In recent years, since rainfall is often acid rain, contamination resistance against dripping of acid rain is important.

Conventionally, as a coating composition used for the exterior of a building or the like, a coating film having performances such as weather resistance, impact resistance, acid resistance, and water resistance can be formed. In addition, a coating composed of a silicone resin (polysiloxane) or an organosilicate condensate having excellent heat resistance may be used. Generally, an organosilicone resin or an organosilicate condensate is used as a reactive hardening group.
It has an OR group, and this reaction curing group causes a hydrolysis condensation reaction using an acid, a base, a metal chelate or the like as a catalyst,
A coating film is formed by generating a Si-O-Si bond.

JP-A-64-1769 discloses a coating composition comprising an organopolysiloxane resin, a zirconium compound and a silyl group-containing vinyl resin using an organopolysiloxane polymer as a binder. This technology uses a zirconium compound as a catalyst to crosslink an organopolysiloxane resin and a silyl group-containing vinyl resin to form a cured coating film, and has excellent chemical resistance and good surface gloss. A uniform and smooth coating film can be obtained. However, since the crosslinking density is low, the hardness is insufficient and the adhesion to the substrate is not sufficient.

Japanese Patent Application Laid-Open No. SHO 51-151 discloses a binder obtained by subjecting methyltrimethoxysilane to hydrolysis and condensation as a binder.
Japanese Patent No. 2736 discloses a coating composition in which methyltrimethoxysilane and tetraethoxysilane are hydrolyzed and condensed to become a binder. This technology uses Si-
Since the CH ₃ group is contained, the resulting coating film exhibits water repellency.

Japanese Patent Application Laid-Open No. 4-117473 discloses a compound obtained by hydrolyzing and condensing methyltrimethoxysilane as a binder and an acrylic polymer having an alkoxysilyl group. A coating composition comprising an acrylic resin, an aluminum compound and tetramethyl silicate is disclosed. In this technique, an aluminum compound is used as a catalyst to hydrolyze and condense SiOR groups in a composition to obtain a cured coating film. The obtained coating film has a surface gloss, hardness, adhesion to a substrate, Alkali resistance, acid resistance,
It is excellent in water resistance and weather resistance and can provide a coating film having a high film thickness limit.

A product obtained by hydrolyzing and condensing methyltrimethoxysilane is used as a binder, and an oxide such as silica sol or alumina sol is blended.
No. 42 discloses a coating composition obtained by adding a pigment to a condensation reaction product comprising methyltrimethoxysilane, aqueous colloidal silica, and an organic acid. This technique involves hydrolysis condensation of methyltrimethoxysilane itself and curing reaction of SiOH groups on the surface of colloidal silica. However, due to the presence of a large amount of water in the coating composition, storage stability is poor and must be used within 24 hours, or the resulting coating film has a degree of condensation of a condensate of methyltrimethoxysilane. When the film thickness is 3 μm or more, cracks are likely to occur.

Japanese Patent Application Laid-Open No. 61-268770 discloses an alumina-based coating composition comprising colloidal alumina and methyltrimethoxysilane. In this technique, a method has been devised in which an alumina sol is blended to positively charge the surface of the coating film to prevent adhesion of dirt such as dust, dust, and dust under dry conditions.

JP-A-63-46272 discloses a coating composition containing a condensate of methyltrimethoxysilane having a molecular weight of 3,000 to 50,000 as a binder and containing colloidal alumina. This technology is
Since a high molecular weight organopolysiloxane is used, the rate of volume shrinkage during the condensation reaction is small, and cracks are unlikely to occur.

Meanwhile, in recent years, importance has been placed on the development of technology for obtaining resistance to raindrop contamination, that is, so-called raindrop contamination resistance, and various proposals have been made. Takayanagi et al. (Abstracts of the Architectural Finishing Society of Japan, 1995 Annual Conference, pp.207-210) reported that raindrop contamination on the exterior walls of buildings was
According to the performance of the outer wall surface, if the outer wall surface is hydrophilic, attached contaminants can be washed away by rainwater.

However, any of the above-mentioned coating compositions comprising a silicone resin or an organosilicate condensate can form a coating film having excellent durability, heat resistance, abrasion resistance, chemical resistance and weather resistance. Although it was possible, sufficient hydrophilicity could not be imparted to the surface of the coating film, so that the resistance to rain dripping contamination was not sufficient. For example, when the organopolysiloxane polymer is used as a binder, the surface of the resulting coating film is not hydrophilic, so that the resistance to rain dripping contamination is poor.
In addition, when a binder obtained by hydrolyzing and condensing methyltrimethoxysilane is used as a binder, the rain streak once adhered cannot be washed away with water such as rainwater because the surface is water-repellent, and the resistance to rain dripping contamination Is not enough.

[0014] A mixture obtained by hydrolyzing and condensing methyltrimethoxysilane as a binder and containing an acrylic polymer having an alkoxysilyl group is formed by hydrolyzing a hydrophilic functional SiOH group in the coating composition. Since the SiOR groups that can be used are almost consumed in the curing reaction, the surface of the coating film cannot be made hydrophilic, and the resistance to rain dripping contamination is not good.

A mixture obtained by hydrolyzing and condensing methyltrimethoxysilane as a binder and an oxide such as silica sol or alumina sol are mixed when forming a coating film.
It is possible to leave the SiOH groups in the coating composition on the surface of the coating film to make it hydrophilic, but in this case, the degree of condensation cannot be increased, so that the film-forming properties deteriorate and cracks occur. It's easy to do. Conversely, if the baking temperature is increased to enhance the film-forming properties, the SiOH groups on the surface of the coating film decrease, and the water wettability deteriorates. In addition, since the surface using alumina sol becomes basic, it has an affinity for an acidic contaminant or the like, so that the contaminant is rather reduced.

Accordingly, there has been developed a paint capable of forming a paint film which is further provided with resistance to rain dripping while maintaining the excellent performance of a paint film obtained from a paint comprising an inorganic binder. For example, a coating composition using a hydrophilizing agent such as an alkoxysilane condensate has been proposed. JP-A-6-145453 discloses a hydrophilic curable composition comprising an alkoxysilyl group-containing acrylic copolymer, a tetraalkyl silicate and / or a condensate thereof, and a curing catalyst. WO9
No. 04/06879 discloses an organosilicate and / or
Alternatively, there is disclosed a coating composition comprising a condensate and having a contact angle of water on the coating film surface after acid treatment of 70 ° or less.

JP-A-7-286126 discloses a hydrolyzate of a fluorine-containing copolymer having a hydrolyzable silyl group, a siloxane compound and / or a hydrolyzate of an acrylic copolymer having a hydrolyzable silyl group. Inorganic consisting of
Binders for organic composite coatings are disclosed. JP-A-7-68217 discloses a liquid compound comprising a hydrolyzate of an alkoxysilane and a polyester resin.

These techniques are based on a Si—O—Si bond or a Si—O—C bond by a hydrolysis condensation reaction of a SiOR group.
While the cured coating film is formed by the formation of a bond or the formation of a urethane bond by a blocked isocyanate, the SiOR group in the added alkoxysilane partially hydrolyzed condensate is hydrolyzed by acid treatment or exposure to the outside to form a hydrophilic Si.
By becoming an OH group and increasing the hydrophilicity of the coating film surface, contaminants adhering to the coating film surface can be washed away with rainwater, and rain dripping contamination resistance can be obtained.

However, in these techniques, cracks occur in the coating film due to the hydrolysis and condensation reaction of the SiOR groups in the cured coating film, and the added alkoxysilane partially hydrolyzed condensate exhibits a hydrophilic effect. It will take some time. This is because, among the SiOR groups of the alkoxysilane partial hydrolysis condensate, those present at the terminal of the molecule are easily hydrolyzed, but the other SiOR groups are not easily hydrolyzed. Therefore, an acid treatment is required to promote the hydrophilic effect of the coating film surface. If the acid treatment is insufficient, it takes time for the hydrolysis to proceed during the exposure, and the hydrophilicity of the coating film surface is insufficient until the hydrolysis reaction sufficiently proceeds. Will stick.

Further, such an alkoxysilane partially hydrolyzed condensate has a small degree of polymerization, and the number of SiOR groups present is at most about 2 per molecule of the alkoxysilane partially hydrolyzed condensate. If an attempt is made to develop the hydrophilicity of the coating film surface from the initial stage of exposure, a large amount of alkoxysilane partially hydrolyzed condensate is required, and cracks occur in the coating film and paint stability deteriorates. Furthermore, the molecular weight is small due to the low degree of polymerization, and when used in baking paint, a considerable amount of the alkoxysilane partially hydrolyzed condensate volatilizes, so that there is a problem that the resistance to rain dripping is insufficient. Was. Therefore, there is a demand for the development of a paint comprising an inorganic binder capable of forming a coating film having excellent resistance to dripping contamination.

By the way, it is generally said that a coating film exhibiting good rain dripping stain resistance has a small contact angle with water. For example, according to the above-mentioned WO 94/06879, the contact angle of water on the coating film surface, that is, the so-called static contact angle is 7
It is said that those having a temperature of 0 degrees or less can exhibit good rain dripping contamination resistance. In addition, a report by Seno et al. (Abstracts of Annual Meetings of the 1995 Japan Society for Finishings, 1995)
According to pp. 214 to 214, a decrease in the static contact angle of water with respect to a coating film was found to be reduced by raindrop contamination by comparing a conventionally used one and a contamination-prevention type one each using a fluororesin paint. The dynamic forward contact angle and the dynamic receding contact angle of water droplets adhering to the coating film are also mentioned.

However, in practice, there are some which have a good resistance to rain dripping even if the static contact angle of water is large. As such a material, for example, when a silicon-containing compound is added to a polyvinylidene fluoride-based fluorine paint, the roughness of the coating film surface increases, the film shifts to water repellency, and the contact angle increases. The property becomes good. It is thought that this is because a film of water is formed by the accumulation of water in the concave portions of the coating film surface, and water droplets containing contaminants quickly flow down on the film. Further, when a coating film is formed by adding a polymer having an alkoxysilyl group to a polyvinylidene fluoride-based fluorine paint, the static contact angle of water hardly changes as compared with the case where the polymer is not added, but the coating film is It is well wetted by water and has good resistance to rain dripping contamination.

This is because the static contact angle of water was measured for conventionally used coating films including the above-mentioned coating film, and the resistance to rain dripping contamination due to exposure for 2 months was evaluated. It is clear from the graphs shown in FIGS. 4 and 5 obtained by examining the relationship. That is, it can be seen from FIG. 4 that there is no correlation between the static contact angle of water and the resistance to rain dripping contamination, and there is a great variation. Also, from FIG. 5, the static contact angle is almost constant irrespective of the addition amount of the polymer having an alkoxysilyl group, but the rain dripping stain resistance is improved as the addition amount of the polymer increases. It can be seen that the decrease in the static contact angle does not always coincide with the decrease in the raindrop contamination.

Such a phenomenon is because the static contact angle of water is a parameter indicating the easiness of spreading of a water drop placed on a horizontal plane and the easiness of spreading of a water drop in a process of starting to wet a vertical or inclined surface. It is considered that raindrop contamination that occurs when rainwater attached to a vertical or inclined surface such as a wall surface or a roof flows down as water droplets cannot be accurately evaluated. Therefore, the static contact angle is
There is not always a correlation with the resistance to rain dripping contamination. To accurately evaluate the resistance to rain dripping contamination, a parameter representing water wettability when a water droplet flows down from a vertical or inclined surface is required.

[0025] As a parameter relating to the state when a water droplet flows down from a vertical or inclined surface, for example, a contact angle of a front end portion or a rear end portion of a moving water droplet can be considered. For example, the report by Seno et al. Suggests that if the dynamic advancing contact angle of water is small, dust on the surface will be washed away well. However, resistance to drooling contamination is not solved solely by dust removal. Although the dynamic receding contact angle of water is also mentioned, Seno et al. Only mentions the parameter as a parameter representing the deformation of the shape of a water drop when the dynamic advancing contact angle of water is small. Since the dynamic receding contact angle of water is the contact angle for receding water droplets on an inclined painted surface, these values depend on the inclined angle of the painted surface, and it is easy to accurately evaluate the resistance to rain dripping contamination. is not. Therefore, the dynamic receding contact angle is not a suitable parameter to discuss its relationship to drooling resistance. In the report of Seno et al., The relationship with the resistance to rain dripping is discussed with a focus on the phase in which water droplets move forward and forward, and a parameter that accurately grasps water wettability when water droplets flow down is presented. Not.

[0026]

DISCLOSURE OF THE INVENTION In view of the above, the present invention provides a coating film having good resistance to raindrop contamination and excellent durability, heat resistance, abrasion resistance, chemical resistance and weather resistance. An object is to provide a coating composition and a coating film forming method.

[0027]

SUMMARY OF THE INVENTION The present invention comprises an inorganic binder composition (A), and comprises a dynamic retraction tension (Tr) of water.
Is a drip-resistant stain-resistant coating film of 47 dyn / cm or more, wherein the inorganic binder composition (A) has the following general formula (1): R ¹ _a —Si (OR ² ) _4-a (1) (Wherein, R ¹ is an alkyl group having 1 to 10 carbon atoms, an epoxyalkyl group having 1 to 11 carbon atoms, an aryl group,
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ² represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. a represents 1, 2 or 3. )), A partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1), the following general formula (2): Si (OR ³ ) ₄ (2) (wherein, R ³ is an alkyl group having 2 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. )), A partially hydrolyzed condensate (A-) of the tetrafunctional alkoxysilane compound (A-3)
4) and the following general formula (3): R ⁴ _b —Si [(OR ⁵ ) _3-b ] —O— (3) (wherein, R ⁴ is an alkyl group having 1 to 10 carbon atoms, Epoxyalkyl group of 1 to 11 groups, aryl group, 1 carbon atom
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. b represents 0, 1, 2 or 3. ) And the following general formula (4): R ⁶ O- (4) (wherein, R ⁶ is an alkyl group having 1 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. ) Is at least one selected from the group consisting of siloxane polymers (A-5) in which at least one of the substituents is bonded to a Si atom in the main chain, and has the following general formula (5) Si [(OR ⁷ ) _{3 -c} ]-(5) (wherein R ⁷ is an alkyl group having 1 to 10 carbon atoms, an epoxyalkyl group having 1 to 11 carbon atoms, an aryl group, and 1 carbon atom)
Represents an aralkyl group of 1 to 11 or an alkenyl group of 1 to 11 carbon atoms. c represents 0, 1 or 2. Having at least one alkoxysilyl group represented by
An alkoxysilyl group-containing vinyl polymer (B-1) having an alkoxysilyl equivalent of 82.8 or more and less than 300,
And, after hydrolyzing an organic silicon compound represented by the following general formula (6): Si (OR ⁸ ) ₄ (6) (wherein R ⁸ represents a methyl group), condensation is performed. A partially hydrolyzed condensate having a hydrolysis rate of less than 100% and a molecular weight of at least one of the partially hydrolyzed condensates (B-2) having a molecular weight of 400 or more and less than 10,000. is there.

Further, the present invention provides a compound represented by the following general formula (1): R ¹ _a —Si (OR ² ) _4-a (1) (where R ¹ is an alkyl group having 1 to 10 carbon atoms, 1 to 11 epoxyalkyl groups, aryl groups, 1 carbon atoms
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ² represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. a represents 1, 2 or 3. )), A partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1), the following general formula (2): Si (OR ³ ) ₄ (2) (wherein, R ³ is an alkyl group having 2 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. )), A partially hydrolyzed condensate (A-) of the tetrafunctional alkoxysilane compound (A-3)
4) and the following general formula (3): R ⁴ _b —Si [(OR ⁵ ) _3-b ] —O— (3) (wherein, R ⁴ is an alkyl group having 1 to 10 carbon atoms, Epoxyalkyl group of 1 to 11 groups, aryl group, 1 carbon atom
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. b represents 0, 1, 2 or 3. ) And the following general formula (4): R ⁶ O- (4) (wherein, R ⁶ is an alkyl group having 1 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. ) Comprises at least one selected from siloxane polymers (A-5) in which at least one of the substituents is bonded to a Si atom in the main chain, and has the following general formula (5): [(OR ⁷ ) _3-c ]-(5) (wherein, R ⁷ is an alkyl group having 1 to 10 carbon atoms, an epoxyalkyl group having 1 to 11 carbon atoms, an aryl group, and 1 carbon atom.
Represents an aralkyl group of 1 to 11 or an alkenyl group of 1 to 11 carbon atoms. c represents 0, 1 or 2. Having at least one alkoxysilyl group represented by
An alkoxysilyl group-containing vinyl polymer (B-1) having an alkoxysilyl equivalent of 82.8 or more and less than 300,
And an organic silicon compound represented by the following general formula (6): Si (OR ⁸ ) ₄ (6) (wherein R ⁸ is a methyl group). (A) a partial hydrolysis condensate having a hydrolysis rate of less than 100% and at least one of partial hydrolysis condensates (B-2) having a molecular weight of 400 to less than 10,000 And a coating composition having a dynamic receding tension (Tr) of water of 47 dyn / cm or more in the obtained coating film.

Further, the present invention provides a method of coating a base material on which at least one primer selected from the group consisting of an epoxy resin primer, a polyurethane-modified epoxy resin primer, and a polyester resin primer is applied. This is a method for forming a coating film which is coated with a composition and baked to form a rain-resistant dripping stain-resistant coating film. Further, the present invention is a coated article having resistance to drooling contamination, which is coated with the above-mentioned coating film having resistance to drooling contamination. Hereinafter, the present invention will be described in detail.

The coating film of the present invention comprises an inorganic binder composition (A), and the inorganic binder composition (A) comprises an alkoxysilyl group-containing vinyl polymer (B-1). ) And partially hydrolyzed condensates (B
-2). The inorganic binder composition (A) refers to a silanol group (Si
OH group) as a curing reaction group, and a film capable of forming a Si—O—Si bond by a hydrolytic condensation reaction to form a crosslinked and cured film can be formed.

The inorganic binder composition (A) comprises an organoalkoxysilane compound (A-1), a partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1), and a tetrafunctional alkoxysilane. Compound (A-
3) It is composed of at least one selected from the partially hydrolyzed condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3) and the siloxane polymer (A-5).

The organoalkoxysilane compound (A)
-1) is the following general formula (1): R ¹ _a —Si (OR ² ) _4-a (1) (wherein, R ¹ is an alkyl group having 1 to 10 carbon atoms and 1 to 11 carbon atoms) Epoxy alkyl group, aryl group, carbon number 1
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ² represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. a represents 1, 2 or 3. ).

R ¹ is an alkyl group having 1 to 10 carbon atoms, an epoxyalkyl group having 1 to 11 carbon atoms, an aryl group, an alkenyl group having 1 to 11 carbon atoms, an aralkyl group having 1 to 11 carbon atoms, 1-4 acyl groups, 1-5 carbon atoms
Represents an aminoalkyl group, a mercaptoalkyl group having 1 to 5 carbon atoms, or a haloalkyl group having 1 to 5 carbon atoms.

The alkyl group having 1 to 10 carbon atoms is not particularly restricted but includes, for example, a linear one such as methyl, ethyl, propyl and n-butyl; and a cyclic one such as cyclopentyl and cyclohexyl. And the like. Among them, a methyl group, an ethyl group, and an n-butyl group are preferable because of good hydrolysis reactivity and condensation reactivity.

The epoxyalkyl group having 1 to 11 carbon atoms is not particularly limited, and examples thereof include a γ-glycidoxypropyl group and a 3,4-epoxycyclohexyl group. The aryl group is not particularly limited, and includes, for example, a phenyl group, a tolyl group, a xylyl group and the like. The alkenyl group having 1 to 11 carbon atoms is not particularly limited, and examples thereof include a vinyl group, an allyl group, a γ-acryloyloxypropyl group, and a γ-methacryloyloxypropyl group. The aralkyl group having 1 to 11 carbon atoms is not particularly limited, and examples thereof include a benzyl group.

The acyl group having 1 to 4 carbon atoms is not particularly limited, and examples thereof include an acryloyl group, a methacryloyl group, a formyl group, an acetyl group and a propionyl group. The aminoalkyl group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include a γ-aminopropyl group. The mercaptoalkyl group having 1 to 5 carbon atoms is not particularly limited.
A mercaptopropyl group and the like can be mentioned. The haloalkyl group having 1 to 5 carbon atoms is not particularly limited,
For example, a γ-chloropropyl group and the like can be mentioned.

The above R ¹ can be appropriately selected in consideration of the physical properties and reactivity of the obtained coating film. For example, when it is desired to suppress cracks in the coating film or to impart alkali resistance, it is known that a phenyl group is selected as R ¹ . Usually, as R ¹ , a methyl group and an ethyl group are generally used, and a methyl group is frequently used from the viewpoint of reactivity.

R ² represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include those exemplified for R ¹ above.
Among them, a methyl group, an ethyl group and an n-butyl group are preferred. The acyl group having 1 to 4 carbon atoms is not particularly limited, and examples thereof include those exemplified for the aforementioned R ¹ . R ² is generally a methyl group or an ethyl group in consideration of hydrolysis reactivity and condensation reactivity, and a methyl group is frequently used.

The above a represents 1, 2 or 3. Especially, 1 is preferable. When a is 1, the organoalkoxysilane compound (A-1) is a trifunctional organoalkoxysilane, and has good hydrolysis reactivity and condensation reactivity. On the other hand, when a is 2 or 3, the organoalkoxysilane compound (A-1) becomes a monofunctional or bifunctional organoalkoxysilane, and has a small number of alkoxysilyl groups involved in the reaction. The condensation reactivity decreases.

When a is 1, specific examples of the organoalkoxysilane compound (A-1) include, for example,
Methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, Vinyltrimethoxysilane, γ
-Glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxytrimethoxysilane, γ-aminopropyltrimethoxysilane, 3,4-epoxycyclohexylethyl Trimethoxysilane and the like can be mentioned. Of these, methyltrimethoxysilane and ethyltriethoxysilane are preferred. These may be used alone or in combination of two or more.

The above organoalkoxysilane compound (A)
-1) is a monomer, and when the paint using this is a one-pack type paint, a hydrolysis-condensation reaction is likely to occur, so a two-pack type paint separated from the catalyst or the like is used. There is a need. However, in the case of a two-pack type paint, workability is not good because a time for a hydrolysis-condensation reaction, that is, a so-called aging period, is required after preparing two liquids. Then, the monomer of the organoalkoxysilane compound (A-1) which has been partially hydrolyzed and condensed in advance can be used. The partially hydrolyzed and condensed reaction is the partially hydrolyzed and condensed product (A-2).

The above-mentioned partially hydrolyzed condensate (A-2) may be any of those obtained by partially hydrolyzing and condensing the above-mentioned organoalkoxysilane compound (A-1).
There is no particular limitation. The hydrolysis-condensation reaction comprises at least one of the organoalkoxysilane compounds (A-1).
It can be carried out by a known method such as a method in which a predetermined amount of water and a catalyst are added to the seed and reacted.

The above tetrafunctional alkoxysilane compound (A-
3) is the following general formula (2): Si (OR ³ ) ₄ (2) (wherein, R ³ is an alkyl group having 2 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. ).

R ³ represents an alkyl group having 2 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. The alkyl group having 2 to 10 carbon atoms is not particularly limited, and examples thereof include an ethyl group, a propyl group, and an n-butyl group. Among them, an ethyl group and an n-butyl group are preferred. When the above R ³ is a methyl group, the condensation reactivity becomes too high, and when used as a binder component, cracks are easily generated in the coating film, and the chemical resistance such as acid resistance and alkali resistance is poor, which is not preferable. . The above carbon number 1
No particular limitation is imposed on the acyl group of ( ^{1) to (4).}
And the like.

The above tetrafunctional alkoxysilane compound (A-
3) is not particularly limited, and examples thereof include tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane. Especially, tetraethoxysilane is preferable.

The above tetrafunctional alkoxysilane compound (A-
3) is a monomer and cannot be used as a one-pack type paint like the organoalkoxysilane compound (A-1), and needs to be a two-pack type paint. Accordingly, in the case of a one-pack type paint, the tetrafunctional alkoxysilane compound (A-3) is partially partially hydrolyzed and condensed in advance similarly to the organoalkoxysilane compound (A-1). Can be used. The partially hydrolyzed and condensed reaction is the partially hydrolyzed and condensed product (A-4).

The above-mentioned partially hydrolyzed condensate (A-4) can be obtained from the above-mentioned tetrafunctional alkoxysilane compound (A-3) by a known method. For example, a necessary amount of water and a catalyst are added to at least one of the above-mentioned tetrafunctional alkoxysilane compounds (A-3), and if necessary, a solvent is added to remove an alcohol generated by the hydrolytic condensation reaction. Gain by doing. Alternatively, it can be obtained by obtaining an oligomer which is a condensate of the above-mentioned tetrafunctional alkoxysilane compound (A-3), and then reacting the oligomer.

The water used for the hydrolysis is not particularly limited. However, if impurities such as ions remain in the coating film, the performance of the coating film is generally deteriorated. It is preferable to use deionized water, pure water or ultrapure water.

The catalyst is not particularly restricted but includes, for example, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid; organic acids such as carboxylic acid and sulfonic acid; inorganic bases such as ammonia, sodium hydroxide and amine; Bases and the like can be mentioned. The solvent is not particularly limited, for example,
Organic solvents such as alcohols, ethers and ketones can be mentioned.

The partially hydrolyzed condensate (A-4) thus obtained contains a monomer, a dimer, a trimer, and a multimer higher than the monomer. In addition, the storage stability of the partial hydrolysis condensate (A-4) itself may be reduced, or the storage stability of a coating composition using the same may be reduced. However, it is not preferable because water resistance, acid resistance, alkali resistance, crack resistance and the like can be reduced. Therefore, it is necessary to remove the monomer by a known method for removing the monomer.

The amount of water used to obtain the above partially hydrolyzed condensate (A-4) is determined from the desired hydrolysis rate. Usually, the hydrolysis rate is 0 to 100%.
In the case of the above-mentioned tetrafunctional alkoxysilane compound (A-3), the hydrolysis rate is as follows: Si (OR ³ ) ₄ + xH ₂ O → Si (OR ³ ) _4-2x O _x
+ 2 × R ³ OH, hydrolysis rate (%) = (2 × / 4) × 100 = (x / 2)
× 100.

In this case, when all the alkoxysilyl groups are hydrolyzed, the hydrolysis rate is 100%,
The hydrolysis ratio of two alkoxysilyl groups is 50%. Similarly, the tetrafunctional alkoxysilane compound represented by the general formula (2) (A-
3) and those in which all the hydrolyzable alkoxysilyl groups of the oligomers are hydrolyzed have a hydrolysis rate of 100%, and those in which the alkoxysilyl groups are partially hydrolyzed are hydrolyzable. It is expressed by the ratio of hydrolyzed alkoxysilyl groups to all the alkoxysilyl groups.

Theoretically, the hydrolysis rate for obtaining the partially hydrolyzed condensate (A-4) is 0% <(hydrolysis rate) <100%. If the hydrolysis rate is 100%, complete S
An iO ₂ solid having a hydrolysis rate of more than 70% is a gelatinous gel or solid having a hydrolysis rate of 6%.
Those having a hydrolysis rate of about 5 to 70% are most preferable because they have a high viscosity and further react with a small amount of water in the air to cause gelation and poor storage stability. However, even with a hydrolysis rate close to 100%, by selecting an appropriate solvent,
The hydrolysis rate is not limited to the above range, since sufficient storage stability may be exhibited.

In the case of having a hydrolysis rate close to 100%, for example, an organic solvent such as an alcohol for performing a hydrolysis-condensation reaction is left after the reaction, and the partially hydrolyzed condensate is diluted. By doing so, storage stability can be increased. When the above-mentioned partially hydrolyzed condensate is diluted with the above-mentioned organic solvent, the hydrolysis rate is 20%.
More than 100% can be used. 20
%, It is not preferable because the monomer tends to remain.

As the partially hydrolyzed condensate (A-4), a partially hydrolyzed condensate of tetraethoxysilane is preferable. Among them, those having a SiO ₂ content of 40% are preferably used. Containing amount of the SiO ₂ is 40%, are commercially available, for example, (manufactured by Colcoat Co.) ES-40, Silicate 40 (manufactured by Tama Chemicals Co., Ltd.), TE
S40 (manufactured by Hoechst), Sylbond 40 (manufactured by Stofffer), ethyl silicate 40 (manufactured by Union Carbide), and the like can be given. These commercially available products are oligomers, and include a mixture of monomers, dimers, trimers, and higher multimeric compounds. Those containing low-molecular-weight components such as monomers are inconvenient in the coating composition and coating film obtained as described above. Therefore, it is preferable to select low-molecular-weight components having low low-molecular-weight components.

The partially hydrolyzed condensate (A-4) can contain a large amount of a reaction hardening group, an SiOH group, and a SiOR group capable of producing the same. The amount of the reactive hardening group is usually much larger than dry silica such as fumed silica or wet silica such as silica sol used as a coating composition, and the above partially hydrolyzed condensate (A-4) The amount of the reactive hardening group of (1) is, for example, in the case of a partial hydrolysis condensate of tetraethoxysilane,
0.1 to 3 mol per mol is preferred. More preferably, it is 0.5 to 2.7 mol.

By the way, the reaction hardening group SiOH
The abundance of the group can be considered including the abundance of the SiOR group. This is described below. The above SiO
The quantitative ratio between the H group and the SiOR group varies depending on the type of the monomer used, the degree of the hydrolytic condensation reaction, the type of the solvent used in the hydrolytic condensation step, and the type of the diluting solvent after the condensation. For example, when an alcohol-based solvent is used as a diluting solvent after condensation, the above-mentioned SiOH group becomes an SiOR group by alcohol exchange with an alkoxyl group in the solvent.
However, since the SiOR group can regenerate the SiOH group which is a reaction hardening group by hydrolysis, the amount including both of them can be the amount of the reaction hardening group.

Using the partial hydrolysis condensate of tetraethoxysilane as the partial hydrolysis condensate (A-4),
From the ¹ H-NMR integrated value and the result of CHN analysis, the amount of the reaction hardened group when suspended in an isopropyl alcohol solvent was calculated based on 1 mole of Si atom per mole of Si atom after 2 days of hydrolysis.
The OH group is 0.72 ± 0.13 mol, the SiOEt group (Et represents an ethyl group) is 0.64 ± 0.12 mol, and the SiO-iPr group (iPr represents an isopropyl group) is , 0.30 ± 0.06 mol. On the other hand, in the case of dry silica (Aerosil 200, particle size of about 100 °, manufactured by Nippon Aerosil Co., Ltd.), SiOH is used per mole of Si atom.
The group is 2 × 10 ⁻⁵ mol, and in a silica sol (Snowtex O, particle size: about 100 °, manufactured by Nissan Chemical Industries, Ltd.), the SiOH group is 4 × 10 ⁻⁵ mol per mol of Si atom.

The amount of the above-mentioned reaction-curable groups slightly fluctuates over time. However, the amount of the reaction hardening group after the hydrolysis of the above partial hydrolysis condensate of tetraethoxysilane for 60 days at room temperature is 0.4 mol for the SiOH group and 0.1 mol for the SiOEt group per mol of Si atom. 36 mol, and the SiO-iPr group is 0.17 mol, which is excellent in storage stability. Thus, it can be seen that the partially hydrolyzed condensate (A-4) has a very large amount of reaction hardening groups, unlike silica which is generally used as a coating composition. The reactive functional groups react with one another or with other components in the paint during curing.

[0060] The siloxane polymer (A-5) represented by the following general formula _{^{(3); R 4 b -Si}} [(OR 5) 3-b] -O- (3) ( wherein, R ⁴ has a carbon number 1-10 alkyl groups, C1-C11 epoxyalkyl groups, aryl groups, C1
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. b represents 0, 1, 2 or 3. ) And the following general formula (4): R ⁶ O- (4) (wherein, R ⁶ is an alkyl group having 1 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. And at least one of the substituents represented by) is bonded to a Si atom in the main chain.

The substituent bonded to the Si atom in the main chain is at least one of the substituents represented by the general formula (3) and the substituents represented by the general formula (4). .
R ⁴ is an alkyl group having 1 to 10 carbon atoms,
11 epoxyalkyl groups, aryl groups, 1 to 1 carbon atoms
1 alkenyl group, aralkyl group having 1 to 11 carbon atoms, acyl group having 1 to 4 carbon atoms, aminoalkyl group having 1 to 5 carbon atoms, mercaptoalkyl group having 1 to 5 carbon atoms, or 1 to 5 carbon atoms Represents a haloalkyl group.

The alkyl group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include those exemplified for R ¹ above. Among them, methyl group, ethyl group,
An n-butyl group is preferred. The epoxyalkyl group having 1 to 11 carbon atoms is not particularly limited.
^{And the} like exemplified in ¹ . The aryl group is not particularly limited, and examples thereof include those exemplified for R ¹ above. 1 to 11 carbon atoms
It is not particularly restricted but includes alkenyl groups, for example, and the like can be exemplified those exemplified above R ^1.

The aralkyl group having 1 to 11 carbon atoms is not particularly restricted but includes, for example, those exemplified for R ¹ above. The acyl group having 1 to 4 carbon atoms is not particularly limited, and examples thereof include those exemplified for the aforementioned R ¹ . Is not particularly limited as aminoalkyl groups of 1 to 5 carbon atoms, for example, the R ¹
And the like. The above carbon number 1
The mercaptoalkyl group of Nos. 5 to 5 is not particularly limited,
For example, there may be mentioned such as those exemplified above R ^1. The haloalkyl group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include those exemplified for R ¹ above.

R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include those exemplified for R ¹ above.
The acyl group having 1 to 4 carbon atoms is not particularly limited,
For example, there may be mentioned such as those exemplified above R ^1.

The substituent represented by the general formula (4) becomes an alkoxysilyl group when bonded to a Si atom in the main chain. R ⁶ is an alkyl group having 1 to 10 carbon atoms;
Alternatively, it represents an acyl group having 1 to 4 carbon atoms. The above carbon number 1
The alkyl group of ^No. 10 is not particularly limited, and examples thereof include those exemplified for R ¹ above. Among them, a methyl group, an ethyl group and an n-butyl group are preferred. The acyl group having 1 to 4 carbon atoms is not particularly limited, and examples thereof include those exemplified for the aforementioned R ¹ .

A siloxane polymer (A-5) in which at least one of the substituents represented by the general formula (3) and the substituents represented by the general formula (4) is bonded to Si atoms in the main chain. ) Can be obtained, for example, by a method such as a hydrolysis condensation reaction of an organoalkoxysilane monomer.

In the hydrolysis-condensation reaction of the organoalkoxysilane monomer, an organopolysiloxane is formed by the hydrolysis-condensation reaction of the organoalkoxysilane monomer. For example, first, the above-mentioned organoalkoxysilane monomer is prepared, and if necessary, a water-soluble organic solvent is added. Further colloidal alumina, and
If necessary, water, a stabilizer and the like are added, and the temperature is preferably about 20 ° C. to a reflux temperature, preferably 50 to 80 ° C. for about 3 hours.
The mixture is heated for 0 minutes to 20 hours to carry out a hydrolytic polycondensation reaction.

The organoalkoxysilane monomer is not particularly restricted but includes, for example, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane. Silane, propyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane,
Vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxytrimethoxysilane, γ-
Examples thereof include aminopropyltrimethoxysilane and 3,4-epoxycyclohexylethyltrimethoxysilane. The water-soluble organic solvent is not particularly limited, and examples thereof include alcohol solvents, cellosolve solvents, cellosolve acetate solvents, and the like.

The hydrolysis-condensation reaction of the above-mentioned organoalkoxysilane monomer is known.
As described in JP 126780, it is represented by the following reaction formulas (I) to (III). From this equation, SiO 2
It can be seen that the theoretical amount of water required to hydrolyze all the R groups is 1.5 mole times the above organoalkoxysilane monomer.

[0070]

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In the reaction described in JP-A-3-126789, the amount of the water is usually from 1.0 to 1.0 mol per mol of the organoalkoxysilane monomer.
4.0 moles are preferred. When the amount is less than 1.0 mol, the remaining alkoxyl group increases, and the obtained coating composition may not be cured sufficiently even when applied to a substrate, and the adhesion and hardness between the coating film and the substrate may be insufficient. If the amount decreases and exceeds 4.0 mol, control of the reaction becomes difficult due to the presence of excess water in the reaction solution, and as a result, the storage stability of the obtained solution deteriorates.

As the water, water contained in the colloidal alumina is mainly used. To this, tap water, distilled water, ion-exchanged water and the like are added as necessary to adjust the amount of water. Preferably, distilled water or ion-exchanged water is used.

The siloxane polymer obtained as described above preferably has a molecular weight of about 3,000 to 50,000. The above molecular weight is a value calculated by gel permeation chromatography using a polystyrene conversion method. More preferably, it is 4000 to 30,000.

As the siloxane polymer (A-5), those generally commercially available as organopolysiloxanes can also be used. For example, KR31-B2
681 (manufactured by Toshiba Silicone Co., Ltd.), NR-02C (Toray
Dow).

The above-mentioned inorganic binder composition (A) comprises the above-mentioned organoalkoxysilane compound (A-1), its partially hydrolyzed condensate (A-2), tetrafunctional alkoxysilane compound (A-3), Partially hydrolyzed condensate (A-
4) and a siloxane polymer (A-5) comprising at least one of the above, and an alkoxysilyl group-containing vinyl polymer (B-1) and a partially hydrolyzed condensate (B-2) It contains at least one of them. In the rain dripping stain-resistant coating film of the present invention, the alkoxysilyl group-containing vinyl polymer (B-1) and the partially hydrolyzed condensate (B-2) are hydrophilized for imparting hydrophilicity to the coating film surface. It is used as an agent.

The above alkoxysilyl group-containing vinyl polymer (B-1) is represented by the following general formula (5): Si [(OR ⁷ ) _{3 -c} ]-(5) (wherein R ⁷ is carbon atom 1) Alkyl group of 10 to 10, epoxyalkyl group of 1 to 11 carbon atoms, aryl group, 1 carbon atom
Represents an aralkyl group of 1 to 11 or an alkenyl group of 1 to 11 carbon atoms. c represents 0, 1 or 2. Having at least one alkoxysilyl group represented by
The alkoxysilyl equivalent is 82.8 or more and less than 300.

The above partially hydrolyzed condensate (B-2)
Is obtained by hydrolyzing an organic silicon compound represented by the following general formula (6); Si (OR ⁸ ) ₄ (6) (wherein R ⁸ is a methyl group), followed by condensation. A partially hydrolyzed condensate having a hydrolysis rate of less than 100% and a molecular weight of 400 to less than 10,000 (B-2).

The alkoxysilyl group-containing vinyl polymer (B-1) is represented by the general formula (5). R ⁷ is an alkyl group having 1 to 10 carbon atoms, 1 to 11 carbon atoms.
Represents an epoxyalkyl group, an aryl group, an aralkyl group having 1 to 11 carbon atoms, or an alkenyl group having 1 to 11 carbon atoms. The above c represents 0, 1 or 2.

The alkyl group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group and an n-butyl group. The epoxyalkyl group having 1 to 11 carbon atoms is not particularly limited, and examples thereof include a glycidoxypropyl group and an epoxycyclohexylethyl group. The aryl group is not particularly limited, and includes, for example, a phenyl group. The aralkyl group having 1 to 11 carbon atoms is not particularly limited, and examples thereof include a benzyl group. The alkenyl group having 1 to 11 carbon atoms is not particularly limited, and examples thereof include a vinyl group, an allyl group, an acryloyloxypropyl group, and a methacryloyloxypropyl group. Of these, a methyl group and an ethyl group are preferred because the hydrolysis reaction is fast and the hydrophilic treatment does not take much time. More preferably, it is a methyl group.

The alkoxysilyl group represented by the general formula (5) is not particularly restricted but includes, for example, trimethoxysilyl, triethoxysilyl, ethyldimethoxysilyl, methyldiethoxysilyl and the like. it can. Among them, a trimethylsilyl group is preferred.

The skeleton of the alkoxysilyl group-containing vinyl polymer (B-1) is not particularly limited, and examples thereof include acrylic ones and silicone ones. Among them, acrylic ones are preferred. These may be modified by other components.
The modification is performed in consideration of the compatibility with the resin, the solvent, and the like in the coating composition mixed with the alkoxysilyl group-containing vinyl polymer (B-1), the storage stability of the obtained coating composition, and the like. Other components to be used, for example, a modifying monomer, a modifying resin, and the like are appropriately selected, and the reaction can be performed according to a known method. As the modifying monomer and the modifying resin, those usually used in coating compositions can be used.

The alkoxysilyl group-containing vinyl polymer (B-1) has an alkoxysilyl equivalent of 82.8.
And less than 300. The alkoxysilyl equivalent is preferably as small as possible, and when it is 300 or more, the resulting coating film becomes insufficient in water wettability and rain dripping stain resistance. Preferably, it is 82.8 to 144, and more preferably, 82.8 to 144.
8 to 92.

When the alkoxysilyl group-containing vinyl polymer (B-1) is a homopolymer comprising only an alkoxysilyl group-containing monomer, the alkoxysilyl equivalent is 82.8, and this is most preferred. The above-mentioned alkoxysilyl group-containing vinyl polymer (B-1)
However, when the above-mentioned alkoxysilyl group-containing monomer and another copolymerizable monomer are composed, by adjusting the blending amount of the alkoxysilyl group-containing monomer, the water wettability of the coating film and the resistance to rain dripping contamination are reduced. Can be controlled.

The alkoxysilyl group-containing vinyl polymer (B-1) has a glass transition temperature (Tg) of -20.
Preferably it is ６０60 ° C. If the temperature is lower than −20 ° C., the obtained coating film becomes soft, and if it exceeds 60 ° C., the coating film surface tends to be uneven, and the obtained coating film becomes too hard, which causes cracks. Cheap.

The alkoxysilyl group-containing vinyl polymer (B-1) preferably has a molecular weight of 3,000 to 30,000. If it is less than 3000, the crack resistance is not sufficient, and if it exceeds 30,000, the viscosity becomes large and the coating becomes difficult. More preferably, 5000 to 20,000
It is.

The acid value of the alkoxysilyl group-containing vinyl polymer (B-1) is preferably less than 10 mgKOH / g. When the amount is 10 mgKOH / g or more, the acid groups of the alkoxysilyl group-containing vinyl polymer (B-1) may cause hydrolysis of the alkoxysilyl groups of the alkoxysilyl group-containing vinyl polymer (B-1) or the formation of silanol groups. It becomes a catalyst for the condensation reaction, impairs the stability of the paint such as moisture curability and storage stability under open air, and easily causes cracks in the coating film.

The alkoxysilyl group-containing vinyl polymer (B-1) can be produced, for example, by introducing an alkoxysilyl group into an acrylic polymer. The introduction of the alkoxysilyl group can be carried out by using the alkoxysilyl group-containing monomer and a monomer having a polymerizable unsaturated bond and copolymerizing the monomer with an acrylic monomer. For the introduction of the alkoxysilyl group, another ethylenically unsaturated monomer other than the acrylic monomer can be added, if necessary.

The alkoxysilyl group-containing monomer is not particularly restricted but includes, for example, vinylmethyldimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane, vinyltrimethoxysilane, γ-acryloyloxypropyltrimethoxysilane, γ-methacryloylpropyl Methyldimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-[(2
-Propen-2-yl-oxycarbonyl) benzoyloxy] propylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldiethoxysilane, γ-
Methacryloyloxypropyltriethoxysilane and the like can be mentioned. These may be used alone,
Two or more kinds may be used in combination. Among them, vinyl trimethoxysilane, γ-acryloyloxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane are preferable from the viewpoint of the hydrolysis reaction rate.

Some of these are commercially available, for example, KBM502 (γ-methacryloylpropylmethyldimethoxysilane), KBM503 (γ-methacryloyloxypropyltrimethoxysilane), KBE50
2 (γ-methacryloyloxypropylmethyldiethoxysilane), KBE503 (γ-methacryloyloxypropyltriethoxysilane) (all manufactured by Shin-Etsu Chemical Co., Ltd.) and the like can be preferably used.

The amount of the alkoxysilyl group-containing monomer can be appropriately set as required.
Usually, an alkoxysilyl group-containing vinyl polymer (B-
It is 90 to 100% by weight based on the total amount of 1). More preferably, it is 100% by weight. If it is less than 90% by weight, the alkoxysilyl equivalent becomes large, which is not preferable.

In producing the above-mentioned alkoxysilyl group-containing vinyl polymer (B-1), various monomers can be further used to adjust the physical properties of the coating film. The monomer is not particularly limited, for example,
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate,
Alkyl (meth) acrylates such as t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and lauryl (meth) acrylate; aromatic vinyl compounds such as styrene and vinyltoluene; acrylonitrile, vinyl acetate, acrylic acid, and methacrylic Examples include vinyl compounds such as acids. These may be used alone or in combination of two or more.

When the purpose is to impart flexibility to the coating film and to enhance the processability as a pre-coated metal (PCM), use a monomer containing a soft segment such as an ε-caprolactone-modified (meth) vinyl monomer. Is preferred. Some of the monomers containing the soft segment, for example, the above-mentioned ε-caprolactone-modified acrylic monomer are commercially available. Examples of such a compound include 2-hydroxyethyl (meth) acrylate / ε-caprolactone adduct and polyalkylene glycol mono (meth) acrylate.
FA series, Praxel-FM series (manufactured by Daicel Chemical Industries, Ltd.) and the like.

In addition to the above monomers, if necessary, dimethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, (meth) acrylamide, α-ethyl (meth) acrylamide, N,
Amino group-containing monomers such as N-butoxymethyl (meth) acrylamide and N-methylacrylamide and acrylamides; 2-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
Hydroxyalkyl (meth) acrylates such as 4-hydroxybutyl (meth) acrylate may be used.

The partially hydrolyzed condensate (B-2) is obtained by hydrolyzing the organosilicon compound represented by the general formula (6) and then condensing the product to a degree of hydrolysis of less than 100%. is there. R ⁸ represents a methyl group.

Since the organosilicon compound represented by the general formula (6) is tetramethoxysilane in which R ⁸ is a methyl group, the hardness, acid resistance and alkali resistance of the resulting coating film are improved. Can be.

The partial hydrolysis condensate (B-2) can be obtained by a known method. For example, a required amount of water and a catalyst are added to the organosilicon compound, and the alcohol generated by the hydrolytic condensation reaction is removed to obtain a partially hydrolyzed condensate (B-2). Alternatively, it can be obtained by reacting the oligomer after obtaining an oligomer which is a condensate of the organic silicon compound.

The amount of water used to obtain the above partially hydrolyzed condensate (B-2) is determined from the desired hydrolysis rate. Usually, the hydrolysis rate is 0 to 100%.
In the present invention, the partial hydrolysis condensate (B-2)
Has a hydrolysis rate of less than 100%. Preferably, 0
~ 65%. Within this range, a linear condensate can be obtained. More preferably, 10 to 65%,
More preferably, it is 30 to 60%.

The water used for the hydrolysis reaction of the organosilicon compound is not particularly limited. However, if impurities such as ions remain in the coating film, the coating film performance deteriorates. It is preferable to use deionized water, pure water or ultrapure water.

In the hydrolysis reaction, a catalyst may be used, if necessary. The catalyst is not particularly limited and includes, for example, inorganic acids such as hydrochloric acid, acetic acid, sulfuric acid, and phosphoric acid; and organic acids such as formic acid, propionic acid, oxalic acid, paratoluenesulfonic acid, benzoic acid, phthalic acid, and maleic acid. ;
Alkali catalysts such as potassium hydroxide, sodium hydroxide, calcium hydroxide, and ammonia; organic metals; metal alkoxides; organic tin compounds such as dibutyltin laurate, dibutyltin octate, and dibutyltin diacetate; aluminum tris (acetylacetonate); Titanium tetrakis (acetylacetonate), titanium bis (butoxy) bis (acetylacetonate),
Metal chelate compounds such as titanium bis (isopropoxy) bis (acetylacetonate), zirconium tetrakis (acetylacetonate), zirconium bis (isopropoxy) bis (acetylacetonate); boron compounds such as boron butoxide and boric acid Can be mentioned. These may be used alone or in combination of two or more. The resulting partially hydrolyzed condensate (B-
2) and from the viewpoint of storage stability of the obtained coating composition,
It is preferable to use one or more of a carboxylic acid, a metal chelate compound and a boron compound.

The amount of the catalyst to be added is not particularly limited, but is usually preferably 0.1 to 10 parts by weight based on 100 parts by weight of the organosilicon compound. More preferably, it is 0.5 to 5 parts by weight.

The partially hydrolyzed condensate (B-2) obtained as described above generally contains a monomer, a dimer, a trimer, and a multimer thereof. When the amount of the monomer or the low molecular weight component is large, the storage stability of the partially hydrolyzed condensate (B-2) itself is reduced, and the storage stability of a coating composition using the same is apt to be reduced. Further, the performance of the obtained coating film, for example, water resistance, acid resistance, alkali resistance, crack resistance, and the like are easily reduced. Therefore, it is preferable to first remove the monomer which is the organic silicon compound itself. The above organosilicon compound (monomer) after removal
In the above partially hydrolyzed condensate (B-2).
It is preferable that the content be not more than weight%. More preferably,
0.3% by weight or less. The method for removing the organic silicon compound (monomer) is not particularly limited, and can be performed by a known method.

In the known method for removing the organosilicon compound (monomer), it is sometimes difficult to remove the dimer or trimer. Therefore, the partial hydrolysis condensate of the organosilicon compound may be difficult. It is necessary to devise the manufacturing method of (B-2). These production methods are also known.

In the present invention, the partial hydrolysis condensate (B-2) has a molecular weight of 400 or more and less than 10,000. When it is less than 400, there are many low molecular weight components,
It is liable to be scattered during the baking process, and when blended in an inorganic binder, is considered to be easily reacted or compatible with other binder components, and is unlikely to exhibit rain dripping resistance. On the other hand, if it is 10,000 or more, the partially hydrolyzed condensate (B-2) itself tends to gel at the time of production, and even if gelation does not occur, the viscosity is too large and the handling is poor, so that it falls within the above range. Limited. Preferably, it is 500-6000.

As the partial hydrolysis condensate (B-2), a commercially available product can also be used. As such a material, for example, MKC silicate MS5
1 (manufactured by Mitsubishi Chemical Corporation) has a hydrolysis rate of about 40%, SiO ₂
The component has a molecular weight of about 52%, an average degree of polymerization of 4 to 6, and a molecular weight of 5
00 to 600 are main constituents. In addition, MKC silicate M
S56 (manufactured by Mitsubishi Chemical Corporation) has a hydrolysis rate of about 50% and Si
The O ₂ component is about 56%, the average degree of polymerization is 7 to 10, and the molecular weight is mainly 800 to 1200.

The partial hydrolysis condensate (B-2) has SiOH groups and SiOMe groups as functional groups. Here, Me represents a methyl group. The molar ratio between the SiOH group and the SiOMe group is SiOH group / SiO
The Me group is preferably 1/10 or less. When there are many SiOH groups, a coating film having high hardness can be formed, but a reaction occurs during storage of the coating material, and problems such as thickening and gelation are likely to occur. More preferably, all the substituents are SiOMe groups. As such, for example, MK
C silicate MS51, MKC silicate MS56 (all manufactured by Mitsubishi Chemical Corporation) and the like can be mentioned.

In the coating film of the present invention, the alkoxysilyl group-containing vinyl polymer (B-1)
And the said partially hydrolyzed condensate (B-2) has a function of increasing the hydrophilicity of the coating film surface.

In the coating film of the present invention,
In order to exhibit more excellent resistance to rain dripping, the inorganic binder composition (A) is partially hydrolyzed and condensed with the organoalkoxysilane compound (A-1) and the organoalkoxysilane compound (A-1). Object (A-2),
Further, it is preferable that the resin be at least one selected from the group consisting of the siloxane polymer (A-5) and include the alkoxysilyl group-containing vinyl polymer (B-1).

In this case, as the inorganic binder composition (A), those in which R ² is a methyl group in the organoalkoxysilane compound (A-1) represented by the general formula (1), In the partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1) represented by 1), R ² is a methyl group, and a substituent represented by the general formula (3): A group consisting of a siloxane polymer (A-5) in which at least one of the substituents represented by the general formula (4) is bonded to a Si atom in the main chain, wherein R ⁵ and R ⁶ are methyl groups. at least one selected, and is preferably made of those wherein R ⁷ is a methyl group in the general formula (5) with an alkoxysilyl group-containing vinyl polymer represented (B-1).

On the other hand, the inorganic binder composition (A)
Is composed of at least one of the tetrafunctional alkoxysilane compound (A-3) and the partially hydrolyzed condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3). Preferably contains at least one of the above-mentioned alkoxysilyl group-containing vinyl polymer (B-1) and the above-mentioned partially hydrolyzed condensate (B-2).

In this case, the inorganic binder composition (A) includes a tetrafunctional alkoxysilane compound (A-3) represented by the general formula (2) wherein R ³ is an ethyl group; A partially hydrolyzed condensate (A-4) of a tetrafunctional alkoxysilane compound (A-3) represented by the general formula (2), wherein at least one of R ³ is an ethyl group; The alkoxysilyl group-containing vinyl polymer represented by the formula (5) (B-
In 1), it is preferable that R ⁷ is a methyl group and that the compound includes at least one of the above-mentioned partial hydrolysis condensates (B-2). The reason why the above combination is preferable will be described below.

In this case, the reason why the partially hydrolyzed condensate of tetraethoxysilane is suitable as the above partially hydrolyzed condensate (A-4) is that, as described above, a methyl-based partially hydrolyzed condensate is used. When used as a binder component, the condensation resistance of the methoxy group is high, so the coating film tends to crack and the chemical resistance of the coating film, such as acid resistance and alkali resistance, decreases. When a partially hydrolyzed condensate having a higher carbon number than that of an ethyl system such as a system is used as a binder component, the rate of the hydrolysis condensation reaction is reduced, and the curing and drying of the coating film are slow, and the utility is poor. In addition, when practically used with insufficient curing, unreacted alkoxysilyl groups often undergo a hydrolytic condensation reaction during exposure, causing cracks. Rukoto can.

However, the use of only an ethyl-based binder composed of an ethyl-based partially hydrolyzed condensate has a slower hydrolysis rate than that of a methyl-based hydrophilizing agent, and hardly develops resistance to rain dripping contamination. Therefore, for example, the partial hydrolysis condensate of tetraethoxysilane is used as the partial hydrolysis condensate (A-4), and the partial hydrolysis condensate (B-2) is used.
Are preferred. Here, the ethyl-based binder means one containing an ethoxy group as a main reactive group, and has an alkoxyl group other than an ethoxy group, for example, a propoxy group, a butoxy group, a methoxy group, or the like as a secondary reactive group. Also included. When the ethyl-based binder has the side-reactive group, an ethoxy group (—OEt) and another alkoxyl group (—O
R) and (-OEt) / ｛(-OEt) +
(-OR)｝> 0.1 is preferable, and 0.5 or more is more preferable.

In the rain-dropping stain-resistant coating film of the present invention, the above-mentioned inorganic binder composition (A) may contain, if necessary,
Further, the following may be added. (C-1): the following general formula (7): R ⁹ _d -Si [(OR ¹⁰ ) _3-d ]-(7) (wherein, R ⁹ is an alkyl group having 1 to 5 carbon atoms, an aryl group. An aralkyl group having 1 to 11 carbon atoms, or 1 to 11 carbon atoms
4 represents an acyl group. R ¹⁰ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. d is
Represents 0, 1, 2 or 3. (C-2): Titanium tetraalkoxide and zirconium tetraalkoxide having an alkoxysilyl group represented by the following formula at the terminal or side chain of the vinyl polymer and having an alkoxysilyl equivalent of 300 or more. At least one metal alkoxide among them, (C-3): a hydrolyzed condensate of the metal alkoxide (C-2), (C-4): silica sol, and (C-5): alumina sol. These may be used alone or in combination of two or more.

The alkoxysilyl group-containing vinyl resin (C-1) is represented by the general formula (7). R ⁹ is an alkyl group having 1 to 5 carbon atoms, an aryl group, an aralkyl group having 1 to 11 carbon atoms, or 1 to 5 carbon atoms.
4 represents an acyl group. The alkyl group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group,
Examples thereof include a propyl group, an isopropyl group, an n-butyl group, and a pentyl group.

The aryl group is not particularly limited.
For example, there may be mentioned such as those exemplified above R ^1. The aralkyl group having 1 to 11 carbon atoms is not particularly limited, and examples thereof include those exemplified for R ¹ above. The acyl group having 1 to 4 carbon atoms is not particularly limited, and examples thereof include those exemplified for the aforementioned R ¹ .

R ¹⁰ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include those exemplified for R ¹ above.
The acyl group having 1 to 4 carbon atoms is not particularly limited,
For example, there may be mentioned such as those exemplified above R ^1.

The above-mentioned alkoxysilyl group-containing vinyl resin (C-1) can be prepared, for example, by the following method: (a) a method of copolymerizing an acryloxy-functional silane and a radical polymerizable monomer;
(B) It can be produced by a known method such as a method of reacting a hydrosilane compound represented by the following general formula (8) with a vinyl polymer having a carbon-carbon double bond. Hereinafter, these methods will be described in order.

[0118]

Embedded image

In the formula, R ¹¹ represents an alkoxyl group. R
¹² represents a hydrogen atom or an organic group having 1 to 8 carbon atoms. e
Represents an integer of 1 to 3.

In the above method (a), when the alkoxysilyl group content in the obtained alkoxysilyl group-containing vinyl resin (C-1) is increased, the storage stability of the coating composition is lowered or after the coating composition is cured. The hydrolysis and condensation reaction of the remaining alkoxysilyl groups tends to cause adverse effects such as cracks, and thus makes it difficult to use as a binder component. Therefore, it is preferable to synthesize the acryloxy-functional silane in a reduced amount so that the alkoxysilyl equivalent of the obtained alkoxysilyl group-containing vinyl resin (C-1) is 300 or more.

The method (b) is a method in which the hydrosilane compound represented by the general formula (8) is reacted with a vinyl polymer having a carbon-carbon double bond. R above
¹¹ represents an alkoxyl group. R ¹² is a hydrogen atom,
Alternatively, it represents an organic group having 1 to 8 carbon atoms. The above e is 1-3
Represents an integer.

The hydrosilane compound represented by the general formula (8) is not particularly limited, and examples thereof include halogenated silane compounds such as methyldichlorosilane, ethyldichlorosilane, phenyldichlorosilane, and trichlorosilane;
Alkoxysilane compounds such as methyldimethoxysilane, methyldiethoxysilane, ethyldimethoxysilane, ethyldiethoxysilane, phenyldimethoxysilane, trimethoxysilane, and triethoxysilane; methyldiacetoxysilane, phenyldiacetoxysilane, and triacetoxysilane Acyloxysilane compounds; and aminosilane compounds such as methyldiaminoxysilane, triaminoxysilane, and triaminosilane.
These may be used alone or in combination of two or more.

The vinyl polymer having a carbon-carbon double bond is not particularly restricted but includes, for example, acrylic acid,
Methacrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, methoxydiethylene glycol (meth) acrylate, methoxytetraethylene Mono (meth) acrylate monomers such as glycol (meth) acrylate and allyl acrylate; di (meth) such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and 1,3-butylene glycol di (meth) acrylate Acrylate monomers; tri (meth) acrylate monomers such as trimethylolpropane tri (meth) acrylate and trimethylolethane tri (meth) acrylate; tetramethylolmethanetetra ( (T) a tetra (meth) acrylate monomer such as acrylate; a modified acrylate monomer; vinyl comprising a vinyl compound such as styrene, α-methylsulfonic acid, vinyl chloride and vinyl acetate and a conjugated diene compound such as butadiene, isoprene and chloroprene. Polymer: a vinyl polymer composed of the above vinyl compound and an acrylic acid derivative having a carbon-carbon double bond not involved in polymerization. These may be used alone or in combination of two or more.

In the above method (b), the above-mentioned hydrosilane compound and the above-mentioned vinyl polymer having a carbon-carbon double bond are added by a known suitable method to obtain an alkoxysilyl group-containing vinyl resin. (C-1)
Can be obtained.

As the alkoxysilyl group-containing vinyl resin (C-1), commercially available resins can be used. Examples of such a material include Zemrak (manufactured by Kanegafuchi Chemical Industry Co., Ltd.), Cyril (manufactured by Toshiba Silicone Co., Ltd.), and Silacoat SC8101 (manufactured by Chisso Corporation).

The alkoxysilyl group-containing vinyl resin (C-1) has an alkoxysilyl equivalent of 300 or more. The alkoxysilyl equivalent is the weight (g) of the resin per mole of the alkoxysilyl group. When the alkoxysilyl equivalent is less than 300, Si-O
Although —Si bonds and Si—O—C bonds are easily generated and the coating film hardness is developed, it is not preferable because it has a bad influence on acid resistance and alkali resistance. In addition, since the alkoxysilyl group is excessively present, problems such as gelation due to moisture and cracking after forming a coating film are likely to occur.

When the vinyl resin (C-1) containing an alkoxysilyl group is added to the inorganic binder composition (A), the polymer is prepared by hydrolytic condensation with the inorganic binder composition (A). can do. In particular, the organoalkoxysilane compound (A-1),
This method is preferred when at least one selected from the group consisting of the tetrafunctional alkoxysilane compound (A-3) and the siloxane polymer (A-5) is used. Water is required for the hydrolysis-condensation reaction. The mixing amount of the water is determined based on the inorganic binder composition (A) and the alkoxysilyl group-containing vinyl resin (C-1).
Is usually relative to 1 mol of the alkoxysilyl group contained in
1.0 to 4.0 mol is preferred. When the amount is less than 1.0 mol, the remaining alkoxysilyl group increases, and even when the obtained coating composition is applied to a substrate, it may not be cured sufficiently, and the adhesion between the coating film and the substrate and 3. the hardness decreases;
If the amount exceeds 0 mol, the control of the reaction becomes difficult due to the presence of excess water in the reaction solution, and as a result, the storage stability of the obtained coating composition deteriorates.

The organoalkoxysilane compound (A)
When at least one of the partially hydrolyzed condensate (A-2) of -1) and the partially hydrolyzed condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3) is used, Alkoxysilyl group-containing vinyl resin (C-
1) may be simply mixed with the inorganic binder composition (A). In this case, the obtained coating composition is mainly of a two-pack type, and a hydrolysis-condensation reaction occurs in the course of heating and film formation to form a coating film.

The amount of the alkoxysilyl group-containing vinyl resin (C-1) to be added is 1 to 100 in terms of solid content, based on 100 parts by weight of the inorganic binder composition (A).
Parts by weight are preferred. When the amount is less than 1 part by weight, the chemical resistance of the obtained coating film is not sufficient, and in the case of a thick film, cracks are liable to occur, and when it exceeds 100 parts by weight, abrasion resistance and heat resistance are poor, The storage stability is poor and the water repellency is increased. In the inorganic binder composition (A), the alkoxysilyl group-containing vinyl polymer (B-1) and the partially hydrolyzed condensate (B-2) are contained. Even if at least one of them is contained, the effect of hydrophilization is hardly exhibited.

The metal alkoxide (C-2) is at least one of titanium tetraalkoxide and zirconium tetraalkoxide. The metal alkoxide (C-2) is hydrolyzed in the presence of water, and the hydrolyzate is polycondensed to produce a partial polycondensate. It cures and functions as a binder together with the inorganic binder composition (A).

The titanium tetraalkoxide is not particularly restricted but includes, for example, titanium tetraethoxide,
Examples thereof include titanium tetra n-propoxide, titanium tetra i-propoxide, titanium tetra n-butoxide, titanium tetra sec-butoxide, and titanium tetra t-butoxide. These may be used alone,
Two or more kinds may be used in combination.

The zirconium tetraalkoxide is not particularly restricted but includes, for example, zirconium tetraethoxide, zirconium tetra n-propoxide, zirconium tetra i-propoxide, zirconium tetra n
-Butoxide, zirconium tetrasec-butoxide, zirconium tetra-t-butoxide and the like. These may be used alone or in combination of two or more.

The above-mentioned metal alkoxide (C-2) is rapidly hydrolyzed to release an alcohol to give a corresponding titanium hydroxide or zirconium hydroxide, and to form a hydroxyl substituent of the above-mentioned hydroxide. Polycondensation is carried out to produce a partial polycondensate of the hydroxide, which is further polycondensed to produce a titania component or a zirconia component which is a complete polycondensate. The hydrolysis reaction of the metal alkoxide (C-2) is very fast, and the hydrolysis proceeds even by moisture in the air, and the metal alkoxide (C-2) is condensed. The partially hydrolyzed polycondensate and the completely hydrolyzed polycondensation of the metal alkoxide (C-2) are the hydrolyzed condensate (C-3). The above-mentioned hydrolysis condensate (C-3) may be one produced from the above-mentioned metal alkoxide (C-2) in the above-mentioned inorganic binder composition (A). ) May be obtained by hydrolysis and polycondensation.

When the metal alkoxide (C-2) and / or the hydrolytic condensate (C-3) is added to the inorganic binder composition (A), the organoalkoxysilane compound (A-1), The tetrafunctional alkoxysilane compound (A-3) and the siloxane polymer (A-
When at least one selected from the group consisting of 5) is used, it is preferable that the above-mentioned metal alkoxide (C-2) is blended and hydrolyzed and condensed. In addition, a partial hydrolysis condensate (A-2) of the organoalkoxysilane compound (A-1) and a partial hydrolysis condensate (A-
When at least one of 4) is used, the metal alkoxide (C-2) and the hydrolysis condensate (C-
Any of 3) may be used.

The amount of the metal alkoxide (C-2) and the amount of the hydrolytic condensate (C-3) added are both 2 parts by weight based on 100 parts by weight of the inorganic binder composition (A).
-100 parts by weight are preferred. If the amount is less than 2 parts by weight, the obtained coating composition has poor film-forming properties, and if it exceeds 100 parts by weight, hydrolysis tends to occur and storage stability is poor. More preferably, it is 5 to 30 parts by weight.

In the present invention, the silica sol (C-
4) is added to improve the storage stability, chemical resistance, and gloss of the obtained coating film. The above silica sol (C-4)
Is an organosilica sol or a water-dispersed silica sol, and preferably has a particle size of 10 to 100 nm. The organosilica sol is a colloid solution in which amorphous isolated colloid particles are dispersed in water or an organic solvent. The colloid solution generally contains 50% by weight or less of silica and has a particle size of up to 300 nm, but in the present invention, as described above, the colloid solution preferably has a particle size of 10 to 100 nm.

When the silica sol (C-4) is blended with the inorganic binder composition (A), the silica sol (C-4) can react with an acid catalyst, an amine catalyst, a tin catalyst, moisture, or the like to remove SiOH groups present on the particle surface. The SiOR groups react with each other and reduce the storage stability. For this reason, in the present invention, it is preferable to use a silica sol (C-4) which has been blocked by reacting its surface functional group. When the SiOH groups on the surface are blocked, the silica sol particles become hydrophobic.

The hydrophobicity of the silica sol particles is represented by a hexane tolerance value, and is preferably from 10 to 50 ml.
If it is less than 10 ml, the amount of remaining SiOH groups is too large and storage stability is not improved.
Reactivity is reduced and a strong coating film can not be formed,
The desired hardness and chemical resistance cannot be obtained.

The hexane tolerance value is used to evaluate the degree of hydrophobicity, and the higher the value, the higher the hydrophobicity. The method for measuring the hexane tolerance value is as follows. In a beaker, 2 g of silica sol (30% SiO ₂ component) was mixed and dispersed in 10 ml of acetone, hexane was gradually added to the mixture, and the amount of hexane (ml) required for the mixture to become cloudy was determined. Measure. Amount of this hexane (ml)
Is the hexane tolerance value. In this method, for example, when the surface of the silica sol is hydrophilic, the silica sol and acetone were initially in a good compatibility state, but became incompatible with the addition of a small amount of hexane, and the measurement system became cloudy. Occurs. Conversely, when the silica sol surface is hydrophobic, the higher the hydrophobicity of the silica sol surface, the more hexane is required before cloudiness occurs. Therefore, the degree of hydrophilicity / hydrophobicity of the silica sol surface can be measured by this method.

The above-mentioned organosilica sols are also commercially available, for example, aqueous media (Snowtech, manufactured by Nissan Chemical Industries, Ltd.), methanol-based media (methanol silica sol, manufactured by Nissan Chemical Industries, Ltd.), xylene /
Butanol-based media (XBA-ST, manufactured by Nissan Chemical Industries, Ltd.) and methyl isobutyl ketone (MIBK) -based media (MIBK-ST, manufactured by Nissan Chemical Industries, Ltd.) can be mentioned. Among these, a xylene / butanol medium and a MIBK medium are preferred. These hexane tolerance values are shown in Table 1.

[0141]

[Table 1]

In the present invention, when a methanol-based or xylene / butanol-based medium is used, it is preferable that these silica sols are subjected to a silane coupling treatment to make them hydrophobic in order to increase the hydrophobicity.
The silane coupling treatment can be performed, for example, by adding 10 to 50 parts by weight of a silane coupling agent to 100 parts by weight of an organosilica sol and causing a reaction. In the above method, the amount of the silane coupling agent added is preferably within the above range. 10
When the amount is less than part by weight, the storage stability, chemical resistance and gloss of the obtained inorganic binder composition (A) are not improved,
If it exceeds 50 parts by weight, it remains in the obtained inorganic binder composition (A), and the coating film performance such as coating film hardness, water resistance and moisture resistance is reduced.

The reaction may be carried out at room temperature for one day or more. If it is necessary to accelerate the reaction to shorten the reaction time, the reaction may be heated to an appropriate temperature.
At this time, the heating is performed to such an extent that the silane coupling agents do not condense with each other or react rapidly with the silica sol to increase the viscosity or cause gelation.

The silane coupling agent is not particularly restricted but includes, for example, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and the like.

When the silica sol (C-4) is added to the inorganic binder composition (A), the organoalkoxysilane compound (A-1), the tetrafunctional alkoxysilane compound (A-3) and the siloxane At least one selected from the group consisting of polymers (A-5) is used, or the organoalkoxysilane compound (A
It is used depending on whether at least one of the partially hydrolyzed condensate (A-2) of -1) and the partially hydrolyzed condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3) is used. The type of the silica sol (C-4) is selected.

The organoalkoxysilane compound (A)
-1), the above-mentioned tetrafunctional alkoxysilane compound (A-3)
When at least one selected from the group consisting of the siloxane polymer (A-5) is used, aqueous colloidal silica is used as the silica sol (C-4). The aqueous colloidal silica has low hydrophobicity, but the organoalkoxysilane compound (A-1),
Water for hydrolytic condensation with at least one selected from the group consisting of the tetrafunctional alkoxysilane compound (A-3) and the siloxane polymer (A-5) can be supplied. The hydrolysis-condensation reaction is described in, for example, JP-A-51-2736 and JP-A-55-949.
No. 71, JP-A-59-68377 and the like can be used. At this time, since all necessary water is supplied by the colloidal silica, the amount of SiO ₂ that can be used is limited and cannot be freely controlled. The coating composition thus obtained is composed of the SiOR group of the inorganic binder composition (A) and the SiOR group of the colloidal silica.
It reacts with the H group to form a unit.

On the other hand, as the silica sol (C-4),
When a silica sol of an organic solvent medium having a high hydrophobicity is used, a predetermined amount of water must be added to the inorganic binder composition (A) and the silica sol for a hydrolytic condensation reaction. As the hydrolysis condensation method, a known method can be used.

The organoalkoxysilane compound (A)
When at least one of the partially hydrolyzed condensate (A-2) of -1) and the partially hydrolyzed condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3) is used, the silica sol ( As C-4), it is not necessary to use aqueous colloidal silica, and generally a silica sol of an organic solvent medium having high storage stability is used. Mixing of the above-mentioned hydrolyzed condensate and silica sol of the above-mentioned organic solvent medium can be performed by a known method as disclosed in, for example, JP-A-62-289279.

The amount of the silica sol (C-4) to be added is preferably 5 to 100 parts by weight in terms of solid content based on 100 parts by weight of the inorganic binder composition (A). When the amount is less than 5 parts by weight, only a thin film can be formed, and cracks easily occur in the coating film. When the amount exceeds 100 parts by weight, the amount of the inorganic binder composition (A) is relatively small. In addition, the strength of the coating film is reduced, and the adhesion is also deteriorated. More preferably, it is 10 to 30 parts by weight.

In the present invention, the alumina sol (C-
5) is added for the purpose of increasing the surface hardness of the coating film, improving the chemical resistance, and improving the adhesion to the substrate. The alumina sol (C-5) contains alumina, hydrated alumina and the like at a ratio of about 5 to 25% by weight, and uses an acid such as hydrochloric acid, nitric acid or acetic acid as a dispersion stabilizer. PH 2.0 or more using water as a dispersion medium
6.0.

The above alumina sol (C-5) has an average particle size of 5 × 10 ^{-3 to} 2.5 × 10 ^-1 μm, preferably ¹ × 10 ^-3 μm.
× 10 ^-3 to 1 × 10 ^-1 μm. Examples of the shape of the alumina particles of the alumina sol (C-5) include a granular shape, a rod shape, and a feather shape.

As the alumina sol (C-5), there is a commercially available one. For example, alumina sol-10
0, alumina sol-200 (all manufactured by Nissan Chemical Industries, Ltd.) and the like.

The addition amount of the above alumina sol (C-5)
The amount is preferably 0.5 to 50 parts by weight in terms of solid content based on 100 parts by weight of the inorganic binder composition (A). 0.
If the amount is less than 5 parts by weight, the adhesion of the coating film to the substrate is poor, so that the alkali resistance is inferior. In addition, it is difficult to form a thick coating film, and the coating film is easily cracked. When the value exceeds the above range, the amount of water and the amount of acid incorporated as a stabilizer increase with the addition of the alumina sol, and as a result, the obtained coating composition is liable to gel and has poor stability. More preferably, 1 to 10
Parts by weight.

The coating film of the present invention has a water dynamic retraction tension (Tr) of 47 dyn / cm or more. The dynamic receding tension (Tr) of the water is measured using the measuring apparatus shown in FIG. 1 according to the method of Kubo and Ueda (The Rheological Society of Japan, The 43rd Annual Meeting of the Rheological Symposium, 233 pages, 1995). can do. A test piece 2 on which a coating film to be measured is formed is suspended from a load cell 1 attached to an upper part of the measuring device, a container 4 containing a measuring solution 3 is placed on a support 5, and the support 5 is mounted. By moving the test piece 2 up and down, the test piece 2 is immersed in the measurement liquid 3 or pulled up from the measurement liquid 3. The change of the load F applied to the test piece 2 at this time is measured.

With reference to the weight of the test piece 2 before the test piece 2 is immersed in the measuring solution 3, the load F applied to the test piece 2 is shown in FIG. 3 during one measurement cycle. To change. Here, the point A represents the immersion start point shown in FIG. 2A, and the point B overcomes the surface tension of the measurement liquid 3 and the test piece 2 3, a point at which penetration starts, a point C represents a point at which the test piece 2 starts to be pulled up, and a point Fg represents a point at which the displacement is the same as the point A.

The load at this point Fg corresponds to the backward tension (Fr) of water. From this value, the dynamic retraction tension (Tr) of water can be determined using the following equation (xi). Tr = (Fr−Fb) / P (xi) [where Fb is the buoyancy applied to the test piece 2 and the point Fg
Is zero. P is the peripheral length (mm) of the immersion part of the test piece 2. As described above, the dynamic backward tension (Tr) of water is a value that can be measured only by physical measurement without depending on a special theoretical assumption.

The present inventors have found that the above-mentioned dynamic backward tension (T
In the region where r) is 47 dyn / cm or more, it has been found that clear rain dripping stain resistance is exhibited. When the dynamic retraction tension (Tr) of water is less than 47 dyn / cm, the resistance to rain dripping contamination becomes insufficient, so that the water retraction tension is limited to the above range. It is preferably at least 56 dyn / cm, more preferably at least 60 dyn / cm.

The thickness of the coating film of the present invention is not particularly limited. However, in order to maintain good properties such as durability and abrasion resistance, it is usually 5 to 100 μm in dry film thickness.
It is preferred that

The coating film of the present invention is characterized in that the inorganic binder composition (A) comprises an organoalkoxysilane compound (A-1) and a partially hydrolyzed condensate (A-
2) a vinyl polymer (B) comprising a tetrafunctional alkoxysilane compound (A-3), a partially hydrolyzed condensate thereof (A-4), and a siloxane polymer (A-5), and containing the alkoxysilyl group-containing vinyl polymer (B -1) and at least one of the above-mentioned partially hydrolyzed condensates (B-2) and containing the alkoxysilyl group-containing vinyl polymer (B
-1) and the SiOH group and / or SiOR group contained in the partial hydrolysis condensate (B-2) are retained on the surface of the coating film and are hydrophilic. Therefore, the raindrop-stain-resistant coating film of the present invention has the above-mentioned SiOH group and / or SiOR group retained on the surface of the coating film, and has a dynamic receding tension (Tr) of water of 47 dyn / cm or more. It has excellent resistance to rain dripping contamination.

The coating composition of the present invention has the following general formula (1): R ¹ _a —Si (OR ² ) _4-a (1) (wherein R ¹ is an alkyl group having 1 to 10 carbon atoms, Epoxyalkyl group having 1 to 11 carbon atoms, aryl group, 1 carbon atom
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ² represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. a represents 1, 2 or 3. )), A partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1), the following general formula (2): Si (OR ³ ) ₄ (2) (wherein, R ³ is an alkyl group having 2 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. )), A partially hydrolyzed condensate (A-) of the tetrafunctional alkoxysilane compound (A-3)
4) and the following general formula (3): R ⁴ _b —Si [(OR ⁵ ) _3-b ] —O— (3) (wherein, R ⁴ is an alkyl group having 1 to 10 carbon atoms, Epoxyalkyl group of 1 to 11 groups, aryl group, 1 carbon atom
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. b represents 0, 1, 2 or 3. ) And the following general formula (4): R ⁶ O- (4) (wherein, R ⁶ is an alkyl group having 1 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. ) Comprises at least one selected from siloxane polymers (A-5) in which at least one of the substituents is bonded to a Si atom in the main chain, and has the following general formula (5): [(OR ⁷ ) _3-c ]-(5) (wherein, R ⁷ is an alkyl group having 1 to 10 carbon atoms, an epoxyalkyl group having 1 to 11 carbon atoms, an aryl group, and 1 carbon atom.
Represents an aralkyl group of 1 to 11 or an alkenyl group of 1 to 11 carbon atoms. c represents 0, 1 or 2. Having at least one alkoxysilyl group represented by
An alkoxysilyl group-containing vinyl polymer (B-1) having an alkoxysilyl equivalent of 82.8 or more and less than 300,
And hydrolyzing an organic silicon compound represented by the following general formula (6); Si (OR ⁸ ) ₄ (6) (wherein R ⁸ represents a methyl group), followed by condensation. (A) a partial hydrolysis condensate having a hydrolysis rate of less than 100% and at least one of partial hydrolysis condensates (B-2) having a molecular weight of 400 to less than 10,000 And the dynamic retraction tension (Tr) of the water of the obtained coating film is 47 dyn / cm or more.

The above alkoxysilyl group-containing vinyl polymer (B-1) and the above partially hydrolyzed condensate (B-2)
Of the organoalkoxysilane compound (A-1), its partially hydrolyzed condensate (A-2), and the tetrafunctional alkoxysilane compound (A-
3), preferably from 1 to 300 parts by weight based on 100 parts by weight of at least one solid content selected from the group consisting of the partially hydrolyzed condensate (A-4) and the siloxane polymer (A-5). When the amount is less than 1 part by weight, the resulting coating film does not exhibit water wettability, and thus does not exhibit rain dripping stain resistance. When the amount exceeds 300 parts by weight, water wettability and rain dripping stain resistance are saturated. More preferably, it is 1 to 10 parts by weight. When the partial hydrolysis condensate (B-2) is a partial hydrolysis condensate of tetraalkoxysilane, the organoalkoxysilane compound (A-1), the partial hydrolysis condensate (A-2), The above-mentioned tetrafunctional alkoxysilane compound (A-3), and its partially hydrolyzed condensate (A-
5 to 50 parts by weight based on 100 parts by weight of at least one solid content selected from the group consisting of 4) and the siloxane polymer (A-5).

The inorganic binder composition (A) includes:
If necessary, the following may be further added. (C-1): the following general formula (7): R ⁹ _d -Si [(OR ¹⁰ ) _3-d ]-(7) (wherein, R ⁹ is an alkyl group having 1 to 5 carbon atoms, an aryl group. An aralkyl group having 1 to 11 carbon atoms, or 1 to 11 carbon atoms
4 represents an acyl group. R ¹⁰ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. d is
Represents 0, 1, 2 or 3. ) Having an alkoxysilyl group at the polymer terminal or side chain and having an alkoxysilyl equivalent of 300 or more, (C-2): titanium tetraalkoxide and zirconium tetraalkoxide At least one metal alkoxide, (C-3): a hydrolyzed condensate of the metal alkoxide (C-2), (C-4): silica sol, and (C-5): alumina sol. These may be used alone or in combination of two or more.

It is preferable that the coating composition of the present invention further contains a catalyst (D) for promoting the hydrolysis-condensation reaction of the alkoxysilyl group. The catalyst (D) is not particularly limited, and examples thereof include aluminum acetylacetonate. The amount of the catalyst (D) to be added is preferably 0.1 to 10% by weight in the obtained coating composition. If the amount is less than 0.1% by weight, the effect of adding the catalyst cannot be obtained. If the amount exceeds 10% by weight, the hydrolysis-condensation reaction takes place too quickly, which is not preferable. More preferably, it is 1 to 5% by weight.

The coating composition of the present invention preferably further comprises an organic solvent (E). The above organic solvent (E)
From the viewpoint of the stability of decomposition of the SiOR group during storage,
At least one of an alcohol-based organic solvent and a glycol derivative. The alcohol-based organic solvent is not particularly limited, for example, butanol, octanol,
Diacetone alcohol and the like can be mentioned. The glycol derivative is not particularly limited, for example, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, diethylene glycol monoethyl ether,
Examples thereof include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate.

The coating composition of the present invention may optionally contain
A particulate filler, a pigment, other additives, other organic solvents, and the like may be added. The particulate filler is not particularly limited, and may be, for example, SiO ₂ , TiO ₂ , A
l ₂ O ₃ , Cr ₂ O ₃ , ZrO ₂ , Al ₂ O ₃ .SiO
_{2, 3Al 2 O 3 · 2SiO} 2, mention may be made of fine particles composed of silicate zirconia.

The above-mentioned pigments are not particularly restricted but include, for example, titanium dioxide, carbon black, iron oxide, various calcined pigments, coloring pigments such as cyanine blue and cyaning ray; extenders such as calcium carbonate, clay and barium sulfate. Can be mentioned.

The above-mentioned other additives are not particularly restricted but include, for example, metal powders such as aluminum powders; matting agents such as silica and alumina; defoaming agents; leveling agents; anti-sagging agents; Agent; dispersant; ultraviolet absorber;
Conventional additives such as wax can be used.

The above-mentioned other organic solvents are not particularly limited as long as they are generally used for paints, and examples thereof include toluene, xylene, Solvesso 100, and the like.
Aromatic hydrocarbons such as Solvesso 150; ethyl acetate;
Esters such as butyl acetate; and ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and isophorone. These are appropriately selected in consideration of solubility, evaporation rate, safety, and the like.
These may be used alone or in combination of two or more.

The coating composition of the present invention can be produced, for example, as follows. First, a roller mill,
A pigment-dispersed paste is prepared using a machine commonly used for dispersing pigments, such as a paint shaker, pot mill, disper, or bead mill, and the above-mentioned organoalkoxysilane compound (A-1) and a partially hydrolyzed condensate thereof ( A-2), the above-mentioned tetrafunctional alkoxysilane compound (A
-3), at least one selected from the group consisting of the partially hydrolyzed condensate (A-4) and the siloxane polymer (A-5), various additives, an organic solvent, a curing agent, a catalyst, and the like. Pigment paste. Then, the above-mentioned alkoxysilyl group-containing vinyl polymer (B-
A coating composition is obtained by mixing at least one dissolving varnish of 1) and the partial hydrolysis condensate (B-2) with the pigment paste.

The alkoxysilyl group-containing vinyl polymer (B-1) and the partially hydrolyzed condensate (B
-2) after preparing a composition excluding at least one of the above, the alkoxysilyl group-containing vinyl polymer (B
A coating composition can also be obtained by adding at least one of -1) and the above-mentioned partially hydrolyzed condensate (B-2) as it is to homogenize it.

The coating composition of the present invention comprises an organoalkoxysilane compound (A-1), a partially hydrolyzed condensate (A-2) and a tetrafunctional alkoxysilane compound (A-
3) at least one selected from the group consisting of a partially hydrolyzed condensate (A-4) and a siloxane polymer (A-5), and an alkoxysilyl group-containing vinyl polymer (B-1); Partially hydrolyzed condensate (B-
2) Since it is composed of the inorganic binder composition (A) containing at least one of the above, unlike the inorganic coating composition conventionally used for exteriors of buildings, etc., the obtained coating film Can be made hydrophilic and can exhibit excellent resistance to rain dripping contamination. Conventional coating compositions, in order to increase the hardness of the resulting coating film,
Since most of the SiOR groups and SiOH groups contained in the coating composition were consumed by crosslinking, the hydrophilicity of the surface of the coating film could not be increased. On the other hand, in the coating composition of the present invention, the organoalkoxysilane compound (A-1) and its partially hydrolyzed condensate (A-
2) can be provided by at least one selected from the group consisting of a tetrafunctional alkoxysilane compound (A-3), a partially hydrolyzed condensate (A-4) and a siloxane polymer (A-5); A SiOR group or a SiOH group for making the surface of the coating film hydrophilic is provided by at least one of the above-mentioned alkoxysilyl group-containing vinyl polymer (B-1) and the above-mentioned partially hydrolyzed condensate (B-2). Therefore, while maintaining the performance of the conventional coating composition, even more excellent resistance to rain dripping contamination can be imparted.

In the method for forming a coating film of the present invention, after a substrate is coated with at least one primer selected from the group consisting of an epoxy resin primer, a polyurethane-modified epoxy resin primer, and a polyester resin primer, The above-mentioned coating composition of the present invention is applied and baked so that the dynamic retraction tension (Tr) of the coating film is 47 dyn / cm or more.

The substrate is not particularly limited, and examples thereof include a galvanized steel sheet, an alloyed galvanized steel sheet, a zinc / aluminum-coated steel sheet, an aluminum-coated steel sheet, aluminum and its alloys, copper and its alloys, titanium and its alloys, Plate or sheet of metal material such as vapor-deposited metal, stainless steel plate, cold rolled steel plate, etc .; formed products of these metal materials; organic materials such as plastic; composite plastic materials such as fiber reinforced plastic (FRP); artificial marble , Slate, and other inorganic ceramic substrates; glass, cement, wood, and the like.

In the case where the base material is the above-mentioned metal material, generally, a material whose surface is subjected to, for example, a zinc phosphate treatment, a reaction type chromate treatment, a coating type chromate treatment, or the like is used. Is preferred. Further, the surface subjected to the chromate treatment may be further provided with a thin film type organic composite coating.

In the method for forming a coating film of the present invention, after the primer is applied to the base material, the coating composition is applied. The primer is at least one selected from the group consisting of an epoxy resin primer, a polyurethane-modified epoxy resin primer, and a polyester resin primer.

The method for applying the coating composition is not particularly limited, and examples thereof include a roll coater, an air spray,
Commonly used coating methods such as airless spray and curtain flow coater can be used. These are appropriately selected according to the purpose of use of the base material. In the coating of the coating composition, the thickness of the obtained coating film is not particularly limited, but usually, the dry film thickness is 5 to 100 μm.
m.

The baking conditions can be appropriately changed according to the reaction temperature of the coating composition so that the dynamic retreat tension (Tr) of the obtained coating film is 47 dyn / cm or more.

In the method for forming a coating film of the present invention, the baking conditions are such that the coating composition is cross-linked and cured by Si—O—.
Since this is due to the formation of Si bonds, the dynamic retraction tension (Tr) of water in the obtained coating film is 47 dyn / cm.
This is a very important factor for this. If the baking conditions are such that all of the SiOH groups and SiOR groups contained in the coating composition are consumed for crosslinking, the coating composition will have a dynamic receding tension (T
Even if r) is set to be more than 47 dyn / cm, it is impossible to make the dynamic retreat tension (Tr) of water of the obtained coating film more than 47 dyn / cm. Therefore, the SiOH group and S
It is necessary to set preferable baking conditions according to the content of the iOR group and other curing characteristics. Such conditions include, for example, 80 ° C., 60 minutes to 350 ° C., 10 ° C.
Can be done in minutes. When the coating composition is a room temperature dried coating, it is preferable to dry at room temperature for 1 day or more, preferably 2 to 3 days, more preferably 1 week or more.

The coated product formed with the coating film as described above exhibits good resistance to rain dripping contamination, and thus is suitable as a base material for buildings and the like used outdoors. The painted object is also one of the present invention.

In the present invention, since the binder, which is the main component of the coating composition for forming the coating film, is inorganic, the durability of the coating film made of the inorganic coating composition,
It has properties such as heat resistance, abrasion resistance, chemical resistance, and weather resistance. The hydrophilic alkoxysilyl group-containing vinyl polymer (B-1) and the partially hydrolyzed condensate (B-2) Since it is blended, it also has excellent resistance to rain dripping contamination.
That is, the coating film formed from such a coating composition has a dynamic receding tension (Tr) of water on its surface of 47 dyn.
/ Cm or more, and the resistance to rain dripping contamination can be improved.

The alkoxysilyl group-containing vinyl polymer (B-1) has a polymer skeleton.
Even if the SiOR groups remaining without being hydrolyzed cause a hydrolysis and condensation reaction during exposure to the outdoors, since the stress relaxation effect works, the coating film is less likely to crack. Further, the alkoxysilyl group-containing vinyl polymer (B-1) and the partially hydrolyzed condensate (B-2) do not decompose or volatilize under baking conditions, and thus have excellent water wettability and durability. A coating film having excellent properties can be provided.

That is, problems in a conventional coating film containing an alkoxysilane condensate as an additive, for example, a long time is required for hydrolysis to proceed, and during this time, the contaminant Is attached; SiOR groups and SiOH groups contained in the coating film cause a condensation reaction under the influence of acid rain, etc., and cause cracks in the coating film; since the alkoxysilane condensate is a small molecule, When applied to baking paints, it can be easily volatilized, and a large amount of an alkoxysilane condensate is required, which can solve the problems such as cracks in coatings and adverse effects on paint stability.

The coating composition of the present invention is characterized by having excellent resistance to rain dripping and contamination, and is used for soundproof walls, girder covers, tunnels, etc. of building wall materials, fences, poles, guardrails, highways and the like. It is suitable for road materials such as interior materials, and applications where emphasis is placed on the resistance to rain dripping such as cutting.

[0184]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Production Example 1 Hydrolysis condensate of methyltrimethoxysilane (OS30
9A, 16.5 parts by weight of Daihachi Chemical Industry Co., Ltd., 27.0 parts by weight of titanium oxide (CR95, manufactured by Ishihara Sangyo Co., Ltd.), and SiO ₂ .Al ₂ O ₃ (ASP200, manufactured by Bander Build) 6 as an extender 5.5 parts by weight, 5.0 parts by weight of isobutanol, and 5.0 parts by weight of isopropyl alcohol were charged into a stainless steel beaker and dispersed by a glass bead mill for 30 minutes to obtain a coating solution (solution A).

Production Example 2 30.0 parts by weight of an acrylic silicone resin (OS309D, manufactured by Daihachi Chemical Industry Co., Ltd.), 3.0 parts by weight of aluminum tris (acetylacetone) as a catalyst, 1.0 part by weight of methyl orthoacetate, 6 parts of butyl acetate 0.0 parts by weight were uniformly mixed with a disper to obtain a curing agent liquid (liquid B).

Production Example 3 Homoposome containing alkoxysilyl group
80 parts by weight of xylene and 20 parts by weight of n-butanol were charged into a reactor equipped with a synthetic heating device for Rimmer (PTMSM) , a stirrer, and a reflux condenser, and the temperature was raised to 110 ° C. while stirring and maintained. Methacryloyloxypropyltrimethoxysilane 100
Parts by weight of a mixture consisting of 1.0 parts by weight of t-butylperoxy-2-ethylhexanoate and 3 parts by weight from a dropping funnel.
It was dropped over time. After completion of the dropwise addition, the temperature was maintained at 110 ° C. for 30 minutes, and then 0.5 part by weight of t-butylperoxy-2-ethylhexanoate was added. 2 hours after addition 11
The mixture was stirred at 0 ° C. to obtain PTMSM. PTMS obtained
M is 50.0% of non-volatile content, alkoxysilyl equivalent 83
g / mol, number average molecular weight 10,000.

Production Example 4 Acrylate Containing Alkoxysilyl Group
80 parts by weight of xylene and 20 parts by weight of n-butanol were charged into a reactor equipped with a synthetic resin heating apparatus, a stirrer and a reflux condenser, and the temperature was raised to 110 ° C. while stirring and maintained. 8 parts by weight, ethyl acrylate 3
A mixture comprising 5.6 parts by weight, 18.5 parts by weight of n-butyl methacrylate, 4.4 parts by weight of γ-methacryloyloxypropyltrimethoxysilane, and 1.0 part by weight of t-butyl peroxy-2-ethylhexanoate Was dropped from the dropping funnel over 3 hours. 1 minute for 30 minutes after dropping
The temperature was kept at 10 ° C., and then 0.5 part by weight of t-butylperoxy-2-ethylhexanoate was added. After the addition, the mixture was further stirred at 110 ° C. for 2 hours to obtain an alkoxysilyl group-containing acrylic resin. The obtained alkoxysilyl group-containing acrylic resin had a nonvolatile content of 50.0%, an alkoxysilyl equivalent of 1,800 g / mol, and a number average molecular weight of 10,000.

Production Example 5 Alumina-Containing Organopolysilo
Synthesis of Xan A reaction vessel equipped with a reflux condenser and a stirrer was charged with 100 parts by weight of methyltrimethoxysilane and alumina sol-100.
(Nissan Chemical Industries, Ltd., hydrochloric acid-stabilized aqueous dispersion, containing feathered alumina, solid content concentration 10% by weight) 1 part by weight and 20 parts by weight of water were charged, and heated to 60 ° C. while stirring, and then about 3 parts by weight. Allowed to react for hours. Then, this was cooled to room temperature to obtain an alumina-containing organopolysiloxane having a weight average molecular weight of 6000. The molecular weight was measured by gel permeation chromatography using a polystyrene conversion method.

Preparation Example 6 Tetraethoxysilane Partial Hydrolysis
500 equipped with a reflux condenser for and thermometer and synthesis stirrer decomposed condensation product
tetraethoxysilaneethyl silicate (ES-40, manufactured by Nippon Colcoat Co., Ltd.)
After adding and mixing 34 parts by weight and 570 parts by weight of isopropyl alcohol, 3 parts by weight of 0.1N hydrochloric acid is added, and a hydrolytic condensation reaction is performed at an internal temperature of 60 ° C. for 10 hours to obtain a partially hydrolyzed condensate of tetraethoxysilane. Was. The obtained tetraethoxysilane partially hydrolyzed condensate (IPA solvent suspension) was analyzed by ¹ H-NMR integration ratio and CHN analysis of the isolated product. : 0.72 ± 0.13 mol, SiOEt group: 0.64 ± 0.12 mol, SiO—
iPr group: 0.30 ± 0.06 mol. After 60 days of hydrolysis (leaving at room temperature), 0.4 mol of SiOH group and 0.36 SiOEt group per 1 mol of Si atom.
Mol, SiO-iPr group: 0.17 mol.

Example 1 The liquid A obtained in the production example 1 and the liquid B obtained in the production example 2 were mixed, and the PTMSM obtained in the production example 3 was mixed with the liquid A and the liquid B at a solid content of 100% by weight. To 8 parts by weight of a solid content with respect to parts, thereby obtaining a coating composition 1. The obtained coating composition 1 was sprayed on an aluminum plate (105
0P) and baked at 180 ° C. for 20 minutes. The dry film thickness was 25 ± 5 μm. The dynamic retreat tension (Tr) of water, the resistance to rain dripping contamination, and the resistance to contamination of dust of the obtained coating film were measured. The measuring method was as follows.

Measurement of Dynamic Backward Tension (Tr) of Water The back surface of the surface on which the coating film was formed was back-sealed with a polytetrafluoroethylene tape and was 50 mm long and 2 mm wide.
After a coating film was formed on a test piece having a size of 5 mm and a thickness of 0.5 mm using each coating material, the test piece was applied to the coated plate at a moving speed of the support table of 20 mm / min using the measuring device shown in FIG. The load was measured and the dynamic recoil tension of the water was calculated. The circumference of the coated plate was 150 mm. The results are shown in Table 2.

[0193] A rain-resistant dripping stain-resistant coated plate is installed vertically so that rain flows down from the roof of a 30-cm plate ( three-millimeter pitch, 3 mm pitch, 3 mm deep) with a 10 ° slope. After standing for 2 months, the state of contamination was observed and visually evaluated according to the following evaluation criteria. The results are shown in Table 2. ◎: Rain streaks are not formed ○: Rain streaks are slightly formed △: Rain streaks are considerably formed ×: Rain streaks are markedly formed

According to the method of Yoshizawa et al. (Academic Lecture Meeting of the 1995 Japan Society for Construction Finishes, pp. 203-206, Accelerated A Method), the coating film was stained for 15 minutes, washed with water, and washed with the initial value. The color difference change ΔE was measured and determined according to the following evaluation criteria. The surface color was measured using a commercially available color difference meter. The results are shown in Table 2. ◎: ΔE = 1 or less ○: ΔE = 1 or more and less than 10 Δ: ΔE = 10 or more and less than 20 ×: ΔE = 20 or more

Example 2 A coating composition was prepared in the same manner as in Example 1 except that PTMSM was a partially hydrolyzed condensate of tetramethoxysilane (MKC silicate MS56 (all substituents are methoxy groups), manufactured by Mitsubishi Chemical Corporation). 2 was obtained. The obtained coating composition 2 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was 25 ± 5 μm. Dynamic retreat tension (Tr) of water of the obtained coating film, rain dripping stain resistance,
Stain resistance to dust was measured in the same manner as in Example 1. The results are shown in Table 2.

Example 3 A coating composition was prepared in the same manner as in Example 1 except that PTMSM was a partially hydrolyzed condensate of tetramethoxysilane (MKC silicate MS51 (all substituents are methoxy groups), manufactured by Mitsubishi Chemical Corporation). 3 was obtained. The obtained coating composition 3 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was 25 ± 5 μm. Dynamic retreat tension (Tr) of water of the obtained coating film, rain dripping stain resistance,
Stain resistance to dust was measured in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 1 A comparative coating composition 1 was obtained in the same manner as in Example 1 except that PTMSM was not added. The obtained comparative coating composition 1 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was 25 ± 5 μm. The dynamic receding tension (Tr) of the obtained coating film, the resistance to rain dripping contamination, and the resistance to dust contamination were measured in the same manner as in Example 1. The results are shown in Table 2.

Example 4 In a reaction vessel equipped with a reflux condenser and a stirrer, 100 parts by weight of methyltrimethoxysilane, 100 parts by weight of an alkoxysilyl group-containing acrylic resin obtained in Production Example 4, 20 parts by weight of isopropyl alcohol, water Charge 40 parts by weight,
The mixture was heated to 70 ° C. with stirring and reacted for 8 hours. Then, 40 parts by weight of isopropyl alcohol, 2 parts by weight of aluminum tris (acetylacetonate), and a partially hydrolyzed condensate of tetramethoxysilane [MKC silicate MS
51 (substituents are all methoxy groups), manufactured by Mitsubishi Chemical Corporation]
100 parts by weight of titanium oxide (CR95, manufactured by Ishihara Sangyo Co., Ltd.) was added, and the mixture was dispersed in a glass bead mill for 30 minutes to obtain a pigment dispersion. The PTM obtained in Production Example 3 was used for 100 parts by weight of the solid content of the obtained pigment dispersion.
The coating composition 4 was obtained by blending 8 parts by weight of SM. The obtained coating composition 4 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was 25 ± 5 μm. The dynamic receding tension (Tr) of the obtained coating film, the resistance to rain dripping contamination, and the resistance to dust contamination were measured in the same manner as in Example 1. The results are shown in Table 2.

Example 5 A coating composition was prepared in the same manner as in Example 4 except that PTMSM was a partially hydrolyzed condensate of tetramethoxysilane (MKC silicate MS56 (all substituents are methoxy groups), manufactured by Mitsubishi Chemical Corporation). 5 was obtained. The obtained coating composition 5 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was 25 ± 5 μm. Dynamic retreat tension (Tr) of water of the obtained coating film, rain dripping stain resistance,
Stain resistance to dust was measured in the same manner as in Example 1. The results are shown in Table 2.

Example 6 A coating composition 6 was obtained in the same manner as in Example 4 except that PTMSM was not added. The obtained coating composition 6 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was 25 ± 5 μm. The dynamic receding tension (Tr) of the obtained coating film, the resistance to rain dripping contamination, and the resistance to dust contamination were measured in the same manner as in Example 1. The results are shown in Table 2.

Example 7 100 parts by weight of titanium oxide (CR-95, manufactured by Ishihara Sangyo Co., Ltd.) and 100 parts by weight of isopropyl alcohol were added to 100 parts by weight of the alumina-containing organopolysiloxane obtained in Production Example 5, and the mixture was added to a glass bead mill. For 30 minutes to obtain a coating liquid. 8 parts by weight of the PTMSM obtained in Production Example 3 was blended with 100 parts by weight of the solid content of the obtained coating solution to obtain a coating composition 7. The obtained coating composition 7 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was 15 ± 5 μm. The dynamic receding tension (Tr) of the obtained coating film, the resistance to rain dripping contamination, and the resistance to dust contamination were measured in the same manner as in Example 1. The results are shown in Table 2.

Example 8 A coating composition was prepared in the same manner as in Example 7 except that PTMSM was a partially hydrolyzed condensate of tetramethoxysilane [MKC silicate MS56 (all substituents are methoxy groups), manufactured by Mitsubishi Chemical Corporation]. 8 was obtained. The obtained coating composition 8 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was 15 ± 5 μm. Dynamic retreat tension (Tr) of water of the obtained coating film, rain dripping stain resistance,
Stain resistance to dust was measured in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 2 A comparative coating composition 2 was obtained in the same manner as in Example 7 except that PTMSM was not added. The obtained comparative coating composition 2 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was 15 ± 5 μm. The dynamic receding tension (Tr) of the obtained coating film, the resistance to rain dripping contamination, and the resistance to dust contamination were measured in the same manner as in Example 1. The results are shown in Table 2.

Example 9 20 parts by weight of methyltriethoxysilane, 20% by weight of an IPA medium silica sol (solid content: 30% by weight, water content: 0.8%, dispersion medium: isopropyl alcohol, manufactured by Nissan Chemical Industries, Ltd.), and isopropyl alcohol 60 The parts by weight were uniformly mixed and heated at 60 ° C. for 5 hours. Titanium oxide (CR)
-95, manufactured by Ishihara Sangyo Co., Ltd.) and dispersed by a glass bead mill for 30 minutes to obtain a pigment dispersion. 8 parts by weight of the PTMSM obtained in Production Example 3 was blended with 100 parts by weight of the solid content of the obtained pigment dispersion to obtain a coating composition 9. The obtained coating composition 9 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was about 5 μm. The dynamic receding tension (Tr) of the obtained coating film, the resistance to rain dripping contamination, and the resistance to dust contamination were measured in the same manner as in Example 1. The results are shown in Table 2.

Example 10 A coating composition was prepared in the same manner as in Example 9 except that PTMSM was a partially hydrolyzed condensate of tetramethoxysilane (MKC silicate MS56 (all substituents are methoxy groups), manufactured by Mitsubishi Chemical Corporation). 10 was obtained. Obtained coating composition 1
0 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was about 5 μm. Dynamic retreat tension (Tr) of water of the obtained coating film, rain dripping stain resistance,
Stain resistance to dust was measured in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 3 A comparative coating composition 3 was obtained in the same manner as in Example 9 except that PTMSM was not added. The obtained comparative coating composition 3 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was about 5 μm. Dynamic retreat tension (Tr) of water of the obtained coating film, rain dripping stain resistance,
Stain resistance to dust was measured in the same manner as in Example 1. The results are shown in Table 2.

Example 11 70 parts by weight of the tetraethoxysilane partially hydrolyzed condensate obtained in Production Example 6, 20 parts by weight of a methanol-based silica sol (manufactured by Nissan Chemical Industries, Ltd.), and 10 parts by weight of isopropyl alcohol were mixed. The coating composition 11 was obtained by adding the PTMSM obtained in Production Example 3 to 100 parts by weight of the solid content so as to be 5 parts by weight. The obtained coating composition 11 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was about 5 μm.
The dynamic receding tension (Tr) of the obtained coating film, the resistance to rain dripping contamination, and the resistance to dust contamination were measured in the same manner as in Example 1. The results are shown in Table 2.

Example 12 A coating composition was prepared in the same manner as in Example 11 except that PTMSM was a partially hydrolyzed condensate of tetramethoxysilane (MKC silicate MS56 (all substituents are methoxy groups), manufactured by Mitsubishi Chemical Corporation). 12 was obtained. The obtained coating composition 12 was applied to an aluminum plate in the same manner as in Example 1,
A coating was formed. The dry film thickness was about 5 μm. The dynamic receding tension (Tr) of the obtained coating film, the resistance to rain dripping contamination, and the resistance to dust contamination were measured in the same manner as in Example 1. The results are shown in Table 2.

Example 13 A coating composition was prepared in the same manner as in Example 11 except that PTMSM was a partially hydrolyzed condensate of tetramethoxysilane [MKC silicate MS51 (all substituents are methoxy groups), manufactured by Mitsubishi Chemical Corporation]. 13 was obtained. The obtained coating composition 13 was applied to an aluminum plate in the same manner as in Example 1,
A coating was formed. The dry film thickness was about 5 μm. The dynamic receding tension (Tr) of the obtained coating film, the resistance to rain dripping contamination, and the resistance to dust contamination were measured in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 4 In a reaction vessel equipped with a reflux condenser and a stirrer, 100 parts by weight of methyltrimethoxysilane, 100 parts by weight of an alkoxysilyl group-containing acrylic resin obtained in Production Example 4, 20 parts by weight of isopropyl alcohol, water Charge 40 parts by weight,
The mixture was heated to 70 ° C. with stirring and reacted for 8 hours. Then, 40 parts by weight of isopropyl alcohol, 2 parts by weight of aluminum tris (acetylacetonate), and a partially hydrolyzed condensate of tetramethoxysilane [MKC silicate MS
51 (substituents are all methoxy groups), manufactured by Mitsubishi Chemical Corporation]
100 parts by weight of titanium oxide (CR95, manufactured by Ishihara Sangyo Co., Ltd.) was added, and the mixture was dispersed with a glass bead mill for 30 minutes to obtain Comparative Coating Composition 4. The obtained comparative coating composition 4 was applied to an aluminum plate in the same manner as in Example 1 to form a coating film. The dry film thickness was 25 ± 5 μm. The dynamic receding tension (Tr) of the obtained coating film, the resistance to rain dripping contamination, and the resistance to dust contamination were measured in the same manner as in Example 1. The results are shown in Table 2.

[0211]

[Table 2]

[0212]

According to the present invention, since the inorganic coating film maintains the dynamic retraction tension (Tr) of water at a certain value or more, the resistance to rain dripping contamination is very good. Excellent performance such as durability, heat resistance, abrasion resistance, chemical resistance, weather resistance, etc., and coatings for base materials such as buildings and displays installed outdoors and soundproof walls, and paints for forming them It is suitable as a composition or a coating film forming method.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an apparatus for measuring the dynamic backward tension (Tr) of water.

FIG. 2 is a conceptual diagram showing a state of a test piece when an apparatus for measuring a dynamic backward tension (Tr) of water is operated.

FIG. 3 is a graph showing a change in load applied to a test piece measured by an apparatus for measuring a dynamic backward tension (Tr) of water. The vertical axis represents load, and the horizontal axis represents displacement.

FIG. 4 is a graph showing a relationship between a static contact angle and resistance to rain dripping contamination.

FIG. 5 is a graph showing the relationship between the static contact angle and the resistance to rain dripping contamination when the amount of addition of the alkoxysilyl group-containing polymer is changed.

Claims (23)

[Claims] Claims: 1. A dripping-resistant stain-resistant coating film comprising an inorganic binder composition (A) and having a dynamic retreat tension (Tr) of water of 47 dyn / cm or more, wherein the inorganic binder composition ( A) is the following general formula (1): R ¹ _a —Si (OR ² ) _4-a (1) (wherein, R ¹ is an alkyl group having 1 to 10 carbon atoms and an epoxy group having 1 to 11 carbon atoms) Alkyl group, aryl group, carbon number 1
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ² represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. a represents 1, 2 or 3. )), A partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1), the following general formula (2): Si (OR ³ ) ₄ (2) (wherein, R ³ is an alkyl group having 2 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. )), A partially hydrolyzed condensate (A-) of the tetrafunctional alkoxysilane compound (A-3)
4) and the following general formula (3): R ⁴ _b —Si [(OR ⁵ ) _3-b ] —O— (3) (wherein, R ⁴ is an alkyl group having 1 to 10 carbon atoms, Epoxyalkyl group of 1 to 11 groups, aryl group, 1 carbon atom
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. b represents 0, 1, 2 or 3. ) And the following general formula (4): R ⁶ O- (4) (wherein, R ⁶ is an alkyl group having 1 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. ) Is at least one selected from the group consisting of siloxane polymers (A-5) in which at least one of the substituents is bonded to a Si atom in the main chain, and has the following general formula (5) Si [(OR ⁷ ) _{3 -c} ]-(5) (wherein R ⁷ is an alkyl group having 1 to 10 carbon atoms, an epoxyalkyl group having 1 to 11 carbon atoms, an aryl group, and 1 carbon atom)
Represents an aralkyl group of 1 to 11 or an alkenyl group of 1 to 11 carbon atoms. c represents 0, 1 or 2. Having at least one alkoxysilyl group represented by
An alkoxysilyl group-containing vinyl polymer (B-1) having an alkoxysilyl equivalent of 82.8 or more and less than 300,
And, after hydrolyzing an organic silicon compound represented by the following general formula (6): Si (OR ⁸ ) ₄ (6) (wherein R ⁸ represents a methyl group), condensation is performed. A partially hydrolyzed condensate having a hydrolysis rate of less than 100% and at least one of partially hydrolyzed condensates (B-2) having a molecular weight of 400 to less than 10,000. Stained coating. 2. The inorganic binder composition (A) comprises an organoalkoxysilane compound (A-1), a partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1), and siloxane. The raindrop-stain-resistant coating film according to claim 1, comprising at least one selected from the group consisting of polymers (A-5) and containing an alkoxysilyl group-containing vinyl polymer (B-1). 3. An inorganic binder composition (A) comprising an organoalkoxysilane compound (A-1) represented by the general formula (1), wherein R ² is a methyl group; In the partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1)
² is a methyl group, and a siloxane in which at least one of a substituent represented by the general formula (3) and a substituent represented by the general formula (4) is bonded to a Si atom in the main chain. In the polymer (A-5), at least one selected from the group consisting of those in which R ⁵ and R ⁶ are methyl groups, and an alkoxysilyl group-containing vinyl polymer represented by the general formula (5) (B- is intended include those wherein R ⁷ is a methyl group in 1), and water dynamic rearward tension (Tr) is raindrop-fouling coating film according to claim 2, wherein at 56dyn / cm or more. 4. An inorganic binder composition (A) comprising a tetrafunctional alkoxysilane compound (A-3) and a partially hydrolyzed condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3). The coating film according to claim 1, wherein the coating film comprises at least one of an alkoxysilyl group-containing vinyl polymer (B-1) and a partially hydrolyzed condensate (B-2). . 5. The inorganic binder composition (A) comprises a tetrafunctional alkoxysilane compound (A) represented by the general formula (2).
-3) wherein R ³ is an ethyl group, and R 4 in the partially hydrolyzed condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3) represented by the general formula (2).
³ is at least one of the ethyl groups, and in the alkoxysilyl group-containing vinyl polymer (B-1) represented by the general formula (5), R ⁷ is a methyl group; The dripping-resistant stain-resistant coating film according to claim 4, comprising at least one of the condensates (B-2), and having a dynamic retraction tension (Tr) of water of 56 dyn / cm or more. 6. The inorganic binder composition (A) further comprises the following general formula (7): R ⁹ _d -Si [(OR ¹⁰ ) _3-d ]-(7) (wherein R ⁹ is C1-C5 alkyl group, aryl group, C1-C11 aralkyl group, or C1-C1
4 represents an acyl group. R ¹⁰ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. d is
Represents 0, 1, 2 or 3. ) Having an alkoxysilyl group at the terminal or side chain of the vinyl polymer, and having an alkoxysilyl equivalent of 300 or more (C-1), titanium tetraalkoxide and zirconium tetraalkoxide. A group consisting of at least one metal alkoxide (C-2), a hydrolyzed condensate (C-3) of the metal alkoxide (C-2), a silica sol (C-4), and an alumina sol (C-5) 6. The coating film according to claim 1, wherein the coating film comprises at least one member selected from the group consisting of: 7. The alkoxysilyl group-containing vinyl polymer (B-1) has an alkoxysilyl equivalent of 82.8 to 1
The rain-sludge-resistant stain-resistant coating film according to claim 1, 2, 3, 4, 5, or 6. 8. The inorganic binder composition (A) is obtained by converting a partially hydrolyzed condensate (B-2) into an organoalkoxysilane compound (A-1) and a partially hydrolyzed condensate of the organoalkoxysilane compound (A-1). The decomposition condensate (A-2), the tetrafunctional alkoxysilane compound (A-3), the partial hydrolysis condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3), and the siloxane polymer (A- 5) With respect to 100 parts by weight of at least one solid content,
Claims 1, 4, and 5 comprising 30 parts by weight.
6. The rain-sag stain-resistant coating film according to 6 or 7. 9. The partially hydrolyzed condensate (B-2) comprises a silanol (SiOH group) and a methoxysilyl group (SiOMe).
Group) and SiOH group / SiOMe group = 1/10
The raindrop-stain-resistant stain-resistant coating film according to claim 1, 4, 5, 6, 7 or 8. 10. The following general formula (1): R ¹ _a —Si (OR ² ) _4-a (1) (wherein, R ¹ is an alkyl group having 1 to 10 carbon atoms, Epoxy alkyl group, aryl group, carbon number 1
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ² represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. a represents 1, 2 or 3. )), A partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1), the following general formula (2): Si (OR ³ ) ₄ (2) (wherein, R ³ is an alkyl group having 2 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. )), A partially hydrolyzed condensate (A-) of the tetrafunctional alkoxysilane compound (A-3)
4) and the following general formula (3): R ⁴ _b —Si [(OR ⁵ ) _3-b ] —O— (3) (wherein, R ⁴ is an alkyl group having 1 to 10 carbon atoms, Epoxyalkyl group of 1 to 11 groups, aryl group, 1 carbon atom
Alkenyl group of 1 to 11, aralkyl group of 1 to 11 carbon atoms, acyl group of 1 to 4 carbon atoms, aminoalkyl group of 1 to 5 carbon atoms, mercaptoalkyl group of 1 to 5 carbon atoms, or 1 to 1 carbon atoms 5 represents a haloalkyl group. R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. b represents 0, 1, 2 or 3. ) And the following general formula (4): R ⁶ O- (4) (wherein, R ⁶ is an alkyl group having 1 to 10 carbon atoms, or
Represents an acyl group having 1 to 4 carbon atoms. ) Comprises at least one selected from siloxane polymers (A-5) in which at least one of the substituents is bonded to a Si atom in the main chain, and has the following general formula (5): [(OR ⁷ ) _3-c ]-(5) (wherein, R ⁷ is an alkyl group having 1 to 10 carbon atoms, an epoxyalkyl group having 1 to 11 carbon atoms, an aryl group, and 1 carbon atom.
Represents an aralkyl group of 1 to 11 or an alkenyl group of 1 to 11 carbon atoms. c represents 0, 1 or 2. Having at least one alkoxysilyl group represented by
An alkoxysilyl group-containing vinyl polymer (B-1) having an alkoxysilyl equivalent of 82.8 or more and less than 300,
And an organic silicon compound represented by the following general formula (6): Si (OR ⁸ ) ₄ (6) (wherein R ⁸ is a methyl group). (B) a partially hydrolyzed condensate having a hydrolysis rate of less than 100% and at least one kind of partially hydrolyzed condensate (B-2) having a molecular weight of 400 to less than 10,000. A coating composition characterized in that the coating film obtained has a dynamic recoil tension (Tr) of 47 dyn / cm or more. 11. An inorganic binder composition (A) comprising an organoalkoxysilane compound (A-1), a partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1), and siloxane Polymer (A-5)
The coating composition according to claim 10, comprising at least one selected from the group consisting of: and containing an alkoxysilyl group-containing vinyl polymer (B-1). 12. An inorganic binder composition (A) comprising the organoalkoxysilane compound (A-1) represented by the general formula (1), wherein R ² is a methyl group; In the partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1)
² is a methyl group, and a siloxane in which at least one of a substituent represented by the general formula (3) and a substituent represented by the general formula (4) is bonded to a Si atom in the main chain. In the polymer (A-5), at least one selected from the group consisting of those in which R ⁵ and R ⁶ are methyl groups, and an alkoxysilyl group-containing vinyl polymer represented by the general formula (5) (B- 12. The coating composition according to claim 11, wherein in 1), R ⁷ is a methyl group. 13. An inorganic binder composition (A) comprising:
A functional alkoxysilane compound (A-3);
It consists of at least one kind of the partially hydrolyzed condensate (A-4) of the functional alkoxysilane compound (A-3), and comprises the alkoxysilyl group-containing vinyl polymer (B-1) and the partially hydrolyzed condensate (B-2). 11. The coating composition according to claim 10, which comprises at least one of the above). 14. An inorganic binder composition (A) comprising: a tetrafunctional alkoxysilane compound (A-3) represented by the general formula (2), wherein R ³ is an ethyl group;
In the partially hydrolyzed condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3) represented by the general formula (2), R ³ is an ethyl group, and is composed of at least one kind selected from the general formula ( The alkoxysilyl group-containing vinyl polymer (B-1) represented by 5), wherein R ⁷ is a methyl group, and at least one of a partial hydrolysis condensate (B-2). 14. The coating composition according to 13. 15. An inorganic binder composition (A) comprising: an organoalkoxysilane compound (A-1); a partially hydrolyzed condensate (A-2) of the organoalkoxysilane compound (A-1); Silane compound (A-
3) a partial hydrolysis condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3), and at least one solid content of 100 parts by weight of the siloxane polymer (A-5), 15. The composition according to claim 10, wherein at least one of the alkoxysilyl group-containing vinyl polymer (B-1) and the partially hydrolyzed condensate (B-2) is blended in an amount of 1 to 300 parts by weight. Paint composition. 16. The inorganic binder composition (A) further comprises a compound represented by the following general formula (7): R ⁹ _d -Si [(OR ¹⁰ ) _3-d ]-(7) (where R ⁹ is C1-C5 alkyl group, aryl group, C1-C11 aralkyl group, or C1-C1
4 represents an acyl group. R ¹⁰ represents an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 4 carbon atoms. d is
Represents 0, 1, 2 or 3. A) a vinyl-based resin (C-1) having an alkoxysilyl group at the terminal or side chain of the vinyl polymer and having an alkoxysilyl equivalent of 300 or more, titanium tetraalkoxide and zirconium tetraalkoxide. A group consisting of at least one metal alkoxide (C-2), a hydrolyzed condensate (C-3) of the metal alkoxide (C-2), a silica sol (C-4), and an alumina sol (C-5) 16. The coating composition according to claim 10, which comprises at least one selected from the group consisting of: 17. The method according to claim 1, further comprising a catalyst (D) for promoting a hydrolysis-condensation reaction of the alkoxysilyl group.
The coating composition according to 0, 11, 12, 13, 14, 15 or 16. 18. A solvent (E) comprising at least one of an alcohol-based organic solvent and a glycol derivative.
Claims 10, 11, 12, 13, 14, 1 comprising:
18. The coating composition according to 5, 16 or 17. 19. The alkoxysilyl group-containing vinyl polymer (B-1) has an alkoxysilyl equivalent of 82.8 to less.
The coating composition according to any one of claims 10 to 18, which is 144. 20. An inorganic binder composition (A) comprising a partially hydrolyzed condensate (B-2), an organoalkoxysilane compound (A-1), and a partially hydrolyzed condensate of the organoalkoxysilane compound (A-1). Decomposition condensate (A-2), 4
Solid content of at least one of a functional alkoxysilane compound (A-3), a partially hydrolyzed condensate (A-4) of the tetrafunctional alkoxysilane compound (A-3), and a siloxane polymer (A-5) 5 to 100 parts by weight
Claims 10 and 13 which contain 30 weight part.
The coating composition according to 14, 15, 16, 17, 18 or 19. 21. The partially hydrolyzed condensate (B-2) comprises a silanol (SiOH group) and a methoxysilyl group (SiOM group).
eH) / SiOH group / SiOMe group = 1/1
0, 10, 13, 14, 15, 16, 1
The coating composition according to 7, 18, 19 or 20. 22. An epoxy resin-based primer,
11. After coating at least one primer selected from the group consisting of a polyurethane-modified epoxy resin-based primer and a polyester resin-based primer,
The method according to any one of claims 1 to 21, wherein the coating composition is baked so that the dynamic retreat tension (Tr) of the coating film is 47 dyn / cm or more. Method. 23. A coated article having resistance to drooling contamination, which is coated with the coating film according to any one of claims 1 to 9.