JP2003013048A - Method for water-repellent article production, water- repellent article and solution for water-repellent coating film formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-repellent article having a great contact angle with respect to waterdrop, an excellent waterdrop rollability, a high scuff resistance, and high weathering resistance, to provide a method for producing the same and to obtain a solution for water-repellent coating film formation. SOLUTION: This method for water-repellent article production is characterized by comprising a process for dissolving a chlorosilyl group-containing compound and a fluoroalkyl group-containing silane compound in a solvent containing an alcohol and/or water to give a solution having the chlorine radical in the chlorosilyl group-containing compound substituted by an alkoxy group or hydroxy group, applying the solution to the surface of a substrate and then drying the coated material to form a water-repellent film.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a water-repellent article having a water-repellent film formed on the surface of a substrate such as glass, ceramics, plastic or metal, a water-repellent article and a solution for forming a water-repellent coating.

[0002]

2. Description of the Related Art When forming a water-repellent coating on the surface of a glass or other substrate, it is necessary to improve the bonding strength between the substrate and the water-repellent coating, and when the substrate contains an alkaline component, A technique of forming an underlayer of silicon oxide or the like between a base material and a water-repellent layer is known for the purpose of preventing diffusion and enhancing the durability of the water-repellent coating.

As a technique for forming a water-repellent coating having this underlayer, a technique for forming a two-layer film structure by further forming a water-repellent film after forming an underlayer film of silicon oxide or the like on the substrate, and the underlayer component And a water-repellent component are mixed to form a film on the substrate,
Two techniques are known, which is a technique for forming a base layer and a water repellent layer with a single layer film. The latter has fewer manufacturing steps and is superior in productivity. As the latter technique, for example, Japanese Patent Publication No. 6
3-24554, JP-A-61-215235, JP-A-64-68477, JP-A-4-338137, and JP-A-8-239653.
The features of each are shown below.

Japanese Patent Publication No. 63-24554 discloses a water-repellent surface treating agent obtained by modifying a silanol oligomer (20 to 40 polymer) with a fluoroalkylsilane.

In JP-A-61-215235, a fluoroalkyl group-containing silane compound and a silane coupling agent are hydrolyzed in an alcohol solvent using a catalyst of acetic acid and an organic tin compound to form a cocondensate. A low-reflectance glass having water repellency and antifouling property is disclosed in which the formed liquid is applied to the surface of a substrate and cured by heating.

Japanese Unexamined Patent Publication (Kokai) No. 64-68477 discloses a method for producing a water repellent steel sheet, which is characterized in that an alcohol solution containing an alkoxide such as silicon oxide and a fluoroalkylsilane is applied to the surface of the steel sheet and then heated. Has been done.

In Japanese Patent Laid-Open No. 4-338137, a solution prepared by mixing a silicon alkoxide and a substituted silicon alkoxide in which a part of an alkoxyl group is substituted with a fluoroalkyl group, alcohol, water, and an acid or a base is prepared on a glass substrate. Disclosed is a water-repellent glass which is characterized by being applied to the surface and then fired.

JP-A-8-239653 discloses a water repellent article treated with a composition comprising a mixture of a perfluoroalkylalkylsilane and a completely hydrolyzable silane.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the methods disclosed in JP-A No. 24554, JP-A-61-215235, and JP-A-4-338137,
Using a catalyst in an alcohol solution, a fluoroalkyl group-containing silane and a silicon alkoxide are hydrolyzed to form a condensation polymer and a cocondensate. As a result, the polymers are bonded to each other, so that a gap is likely to be formed and the denseness of the water-repellent coating is lowered. Therefore, a firing process is required to increase the denseness, which causes a cost increase.

In the method disclosed in JP-A-64-68477, the reactivity is inferior because the catalyst is not added, and the denseness of the water-repellent coating becomes low. Therefore, a firing process is required to increase the denseness, which causes a cost increase.

In the technique disclosed in JP-A-8-239653, chlorosilane and a non-aqueous solvent are preferably used in the coating composition. However, non-aqueous solvents are expensive. Further, when this coating composition was retested, it reacted with moisture in the air and gelled and became unstable. Therefore, the humidity of the atmosphere was 10% RH or less, preferably 0% R.
It has been found that it is necessary to maintain close to H, and it is difficult to control environmental conditions. Further, when this technique was additionally tested, it was also found that the surface of the water-repellent coating had fine irregularities, which had the drawback of low scratch resistance of the coating.

Furthermore, when the above-mentioned technique is retested,
It was found that the water repellency of any of the water repellent articles was not good.

In view of the above-mentioned circumstances, the present invention is a water-repellent article having excellent water repellency, specifically, a large contact angle of water droplets and excellent rolling property of water droplets, and high scratch resistance. An object of the present invention is to provide a water-repellent article having water resistance and weather resistance, a method for producing the same, and a solution for forming a water-repellent film.
Another object of the present invention is to provide a method for producing a water-repellent article and a solution for forming a water-repellent coating, which makes it easy to control the humidity of the atmosphere during storage and coating operations.

[0014]

Means for solving the problems Means for solving the above problems are as follows. That is, as a claim 1, a solution in which a chlorosilyl group-containing compound and a fluoroalkyl group-containing silane compound are dissolved in a solvent containing alcohol and / or water, and the chloro group of the chlorosilyl group-containing compound is substituted with an alkoxyl group or a hydroxyl group. Is applied to the surface of a base material and then dried to form a water-repellent coating film.

As a second aspect, a solution containing a silicon alkoxide or a hydrolyzate thereof as a monomer or a polymer of 19-mer or less, and further containing a fluoroalkyl group-containing silane compound and an acid is applied to the surface of the substrate. A method for producing a water-repellent article, comprising the steps of applying and then drying to form a water-repellent coating.

A third aspect of the present invention is the water-repellent article obtained by the method according to the first or second aspect, wherein the surface of the water-repellent coating has an arithmetic average roughness (Ra) of 0.5 nm or less and a ten-point average. The water-repellent article is characterized by having a roughness (Rz) of 5 nm or less.

A fourth aspect of the present invention is the water-repellent article obtained by the method according to the first or second aspect, wherein the fluorine concentration on the surface of the water-repellent coating is 0 in terms of the atomic ratio of fluorine atoms and silicon atoms. It is a water-repellent article of 0.8 or more.

As a fifth aspect, the chlorosilyl group-containing compound and the fluoroalkyl group-containing silane compound are dissolved in a solvent containing alcohol and / or water, and the chloro group of the chlorosilyl group-containing compound is replaced with an alkoxyl group or a hydroxyl group. It is a solution for forming a water-repellent film.

A sixth aspect of the present invention is that the silicon alkoxide or its hydrolyzate is contained as a monomer or a polymer of 19-mer or less, and further contains a fluoroalkyl group-containing silane compound and an acid. It is a film forming solution.

As a seventh aspect, the chlorosilyl group-containing compound and the fluoroalkyl group-containing silane compound are dissolved in a solvent containing alcohol and / or water, and the chloro group of the chlorosilyl group-containing compound is substituted with an alkoxyl group or a hydroxyl group. And a silicon alkoxide or a hydrolyzate thereof is contained as a monomer or a polymer of 19-mer or less, which is a water-repellent film forming solution.

Further, in the above-mentioned method for producing a water-repellent article, the solution contains an acid and a water, the concentration of the acid is represented by S (normal), and the concentration of the water is represented by W (% by weight).
1 ≦ S ≦ 3 and 0 ≦ W ≦ 20, respectively, and the ratio of the chlorosilyl group-containing compound to the fluoroalkyl group-containing silane compound is set to be the number of silicon atoms in the chlorosilyl group-containing compound Si (Cl) and the number of silicon atoms in the fluoroalkyl group-containing silane compound, expressed as Si (F), Si (Cl): Si (F) = 100: (0.05-5
It is a method for producing a water-repellent article which dissolves at a ratio of 0).

The acid concentration and the water concentration are 0.01 ≦ S ≦ 1 and 0 ≦ W ≦ 10, respectively, and the ratio is Si (Cl): Si (F) = 100: (0. 05-30)
Which is a method for producing a water-repellent article.

The acid concentration and the water concentration are 0.1 ≦ S ≦ 1 and 0 ≦ W ≦ 2, respectively, and the ratio is
Si (Cl): Si (F) = 100: (0.05 to 3).

The solution contains the chlorosilyl group-containing compound and the fluoroalkyl group-containing silane compound,
It is a method for producing a water-repellent article which dissolves at a total concentration of 0.01 to 10% by weight.

The chlorosilyl group-containing compound is a method for producing a water repellent article which is tetrachlorosilane.

The fluoroalkyl group-containing silane compound contains a fluoroalkyl group and contains an alkoxy group,
A method for producing a water-repellent article, which is a silane compound containing an acyloxy group or a chlorine group.

The fluoroalkyl group-containing silane compound is a method for producing a water-repellent article, which is 3-heptadecafluorodecyltrimethoxysilane or 3-heptadecafluorodecyltrichlorosilane.

The solvent is a method for producing a water-repellent article which is a hydrophilic solvent.

The solvent is a method for producing a water-repellent article which is an alcohol solvent.

The above-mentioned substrate is a method for producing a water-repellent article which is a substrate having a hydrophilic group on its surface.

Further, it is a method for producing a water-repellent article, in which an acid is added and dissolved in the solution.

The above solution has a water content of 0.3% of that of the solution.
It is a method for producing a water-repellent article containing an acid having a concentration of twice or more.

The above-mentioned acid is hydrochloric acid in the method for producing a water-repellent article.

The pH of the solution is 0 to 3 in the method for producing a water-repellent article.

A method for producing a water-repellent article, wherein the water-repellent coating film has a thickness of 5 to 200 nm.

In the water-repellent article obtained by the above method, the surface of the water-repellent coating has an arithmetic mean roughness (Ra).
= 0.5 nm or less and ten-point average roughness (Rz) = 5 nm
A water repellent article having the following roughness.

A water repellent article obtained by the above method, wherein the fluorine concentration on the surface of the water repellent coating film is
The water-repellent article has an atomic ratio of fluorine atoms and silicon atoms of 0.8 or more.

Further, there is provided a water repellent article comprising a base material and a water repellent coating having a fluoroalkyl group as a main component of silicon oxide, which is coated on the surface of the base material by a sol-gel method. Surface has arithmetic mean roughness (Ra) =
A water-repellent article having a roughness of 0.5 nm or less and a ten-point average roughness (Rz) of 5 nm or less.

A water-repellent article comprising a base material and a water-repellent coating film containing a fluoroalkyl group as a main component of silicon oxide, which is coated on the surface of the base material by a sol-gel method. The water-repellent article has a fluorine concentration of 0.8 or more in terms of the atomic ratio of fluorine atoms to silicon atoms.

Furthermore, in the above-mentioned water-repellent film forming solution, the solution represents acid and water, the acid concentration is represented by S (normal) and the water concentration is represented by W (wt%),
0.001 ≦ S ≦ 3, 0 ≦ W ≦ 20, respectively, and the ratio of the chlorosilyl group-containing compound to the fluoroalkyl group-containing silane compound is set to the ratio of the silicon atom in the chlorosilyl group-containing compound. Number Si (Cl) and the number of silicon atoms in the fluoroalkyl group-containing silane compound S
Expressed by i (F), Si (Cl): Si (F) = 100: (0.0
It is a water-repellent film-forming solution that is dissolved at a ratio of 5 to 50).

The concentration of the acid and the concentration of the water are 0.01 ≦ S ≦ 1 and 0 ≦ W ≦ 10, respectively, and the ratio is Si (Cl): Si (F) = 100: (0. 05-30)
Is a solution for forming a water-repellent film.

The acid concentration and the water concentration are 0.1 ≦ S ≦ 1 and 0 ≦ W ≦ 2, respectively, and the ratio is
Si (Cl): Si (F) = 100: (0.05 to 3) A water-repellent film forming solution.

The solution contains the chlorosilyl group-containing compound and the fluoroalkyl group-containing silane compound,
It is a water-repellent film-forming solution that dissolves at a total concentration of 0.01 to 10% by weight.

The chlorosilyl group-containing compound is a water-repellent film forming solution which is tetrachlorosilane.

The fluoroalkyl group-containing silane compound contains a fluoroalkyl group and has an alkoxy group,
A solution for forming a water-repellent film containing an acyloxy group or a chlorine group.

The fluoroalkyl group-containing silane compound is a water-repellent film forming solution which is 3-heptadecafluorodecyltrimethoxysilane or 3-heptadecafluorodecyltrichlorosilane.

The solvent is a water-repellent film forming solution which is a hydrophilic solvent.

The solvent is a water-repellent film forming solution which is an alcohol solvent.

Further, a solution for forming a water-repellent film is obtained by adding and dissolving an acid to the above solution.

The solution has a water content of 0.3 of the solution.
It is a solution for forming a water-repellent film, which contains an acid having a concentration more than double.

The acid is a solution for forming a water-repellent film, which is hydrochloric acid.

The solution has a pH of 0 to 3 for forming a water-repellent film.

The compounds, solvents and the like used in the present invention will be described in detail below. The chlorosilyl group-containing compound used in the present invention means a chlorosilyl group (-SiC
l _n X _3-n , where n is 1, 2, or 3. X is hydrogen, or a compound having at least one hydrogen atom, or an alkyl group, an alkoxy group, or an acyloxy group each having 1 to 10 carbon atoms in the molecule.

Among them, at least two chlorine atoms are included.
The compound is preferably silane Si _nH_{2n + 2}(Where n
Is an integer of 1 to 5) and at least 2 hydrogens are chlorine.
With other hydrogen, if necessary, the other alkyl group,
Chlorosyl substituted with lucoxy or acyloxy groups
And its partial hydrolyzate and its polycondensate
preferable.

For example, tetrachlorosilane SiC
l ₄ , trichlorosilane SiHCl ₃ , trichloromonomethylsilane SiCH ₃ Cl ₃ , dichlorosilane Si
H ₂ Cl _2, and _{Cl- (SiCl 2 O) n -SiCl} 3
(N is an integer of 1 to 10) and the like. Among these, it is possible to use alone or in combination of two or more. The most preferred chlorosilyl group-containing compound is tetrachlorosilane.

As the fluoroalkyl group-containing silane compound used in the present invention, a silane compound containing a fluoroalkyl group and containing an alkoxy group, an acyloxy group or a chloro group can be preferably used. . For example, compounds represented by the following chemical formulas (1) and (2) can be given. Of these,
A single compound or a combination of multiple compounds can be used.

[0057]

Embedded image CF ₃ — (CF ₂ ) _n —R—SiX _p Y _3−p (1) (where n is an integer of 0 to 12, preferably 3 to 1)
An integer of 2, R is a divalent organic group having 2 to 10 carbon atoms (for example, a methylene group, an ethylene group), or a group containing a silicon atom and an oxygen atom, and X is a monovalent hydrocarbon having 1 to 4 carbon atoms. A group (for example, an alkyl group, a cycloalkyl group, an allyl group) or a substituent selected from these derivatives, or hydrogen, p is 0, 1 or 2, and Y is a carbon atom having 1 to 4 carbon atoms.
Alkoxy group or acyloxy group)

[0058]

Embedded image CF ₃ — (CF ₂ ) _n —R—SiX _p Cl _3−p (2) (where n is an integer of 0 to 12, preferably 3 to 1)
An integer of 2, R is a methylene group, an ethylene group, or a group containing a silicon atom and an oxygen atom, X is H or an alkyl group,
Substituent selected from cycloalkyl group, allyl group or derivatives thereof, p is 0, 1 or 2)

Examples of the compound represented by the chemical formula (1) include:
The following are listed.

Embedded image CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃

[Chemical 4]

Embedded image C ₈ F ₁₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃

[Chemical 6]

Embedded image C ₈ F ₁₇ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃

Embedded image C ₈ F ₁₇ CH ₂ CH ₂ Si (OC (CO) CH ₃ )
₃

[Chemical 9]

Among these, C ₈ F ₁₇ CH ₂ CH ₂ S
i (OCH _{3) 3} (3- heptadecafluorodecyltrimethoxysilane) and _{C 8 F 17 CH 2 CH 2} Si (CH
₃ ) (OCH ₃ ) ₂ is particularly preferred.

Further, examples of the compound represented by the chemical formula (2) include the following.

Embedded image CF ₃ CH ₂ CH ₂ SiCl ₃

[Chemical 11]

Embedded image C ₈ F ₁₇ CH ₂ CH ₂ SiCl ₃

[Chemical 13]

Among these, C ₈ F ₁₇ CH ₂ CH ₂ S
iCl ₃ (3-heptadecafluorodecyltrichlorosilane), and C ₈ F ₁₇ CH ₂ CH ₂ Si (CH ₃ ) Cl
₂ is particularly preferred.

Next, the solvent will be described. As the solvent, a solvent containing an alcohol and / or water, which can substitute a chloro group of a chlorosilyl group-containing compound with an alkoxyl group or a hydroxyl group to cause a dehydrochlorination reaction, is used. For example, alcohol-based hydrophilic solvents and ketone-based hydrophilic solvents are preferably used.

Among them, alcohol type, for example, chain saturated monohydric alcohols having 3 or less carbon atoms such as methanol, ethanol, 1-propanol and 2-propanol are more preferably used since they have a high evaporation rate at room temperature. .

Examples of the ketone-based hydrophilic solvent include acetone and methyl ethyl ketone.

The solvent does not necessarily need to contain alcohol as long as the solvent contains water necessary for causing the dehydrochlorination reaction. Furthermore, the solvent does not have to be composed of only a hydrophilic solvent, and may include a non-aqueous solvent such as a hydrocarbon-based solvent or a fluorine-based solvent.

In the production method invention, a solution of the chlorosilyl group-containing compound and the fluoroalkyl group-containing silane compound dissolved in a hydrophilic solvent is applied to the surface of a substrate such as a glass substrate. At that time, the -OH group on the surface of the substrate and the fluoroalkyl group-containing silane compound in the applied film,
Various chemical reactions occur between the chlorosilyl group-containing compound and the hydrophilic solvent.

That is, as described in detail below, the chlorosilyl group reacts in the solution, during the preparation, during the storage, and during the film formation to form a siloxane bond (--Si--O--Si).
-). A part of the changed siloxane bond forms a siloxane bond with the fluoroalkyl group-containing silane compound, and another part forms a siloxane bond with the substrate surface.

For example, when an alcohol solvent is used as the solvent, the chlorosilyl group-containing compound in the solution forms an alkoxide by the dehydrochlorination reaction with the alcohol solvent as shown in the formula (14). In addition, the chlorosilyl group-containing compound causes a hydrolysis reaction due to a small amount of water contained in the alcohol solvent or the atmosphere, and hydrogen chloride can be removed (dehydrochlorination reaction) as shown in formula (15). At this time, silanol (..Si-OH) is generated. R in the formula is an alkyl group.

[0070]

[Chemical 14] (·· Si—Cl) + (ROH) → (·· Si—OR) + (HCl) (14)

Embedded image (·· Si—Cl) + (H ₂ O) → (·· Si—OH) + (HCl) (15)

In an alcohol solvent, formula (14) and formula (1
The hydrochloric acid produced in 5) acts as a catalyst for the reaction of formula (16), and a part of (..Si-OR) further produces silanol.

Embedded image (•• Si—OR) + (H ₂ O) → (•• Si—OH) + (ROH) (16)

Then, a part of the silanol produced by the formulas (15) and (16) reacts as shown by the formula (17) to form a siloxane bond (-Si-O-Si-). Also, some of the silanols produced are of formula (1
As shown in 8), a dehydration condensation reaction is performed to form a siloxane bond.

[0073]

[Chemical 17] (·· Si—Cl) + (·· Si—OH) → (·· Si—O—Si ··) + (HCl) (17)

(•• Si—OH) + (•• Si—OH) → (•• Si—O—Si ••) + (H ₂ O) (18)

The reactivity of the chloro group of the chlorosilyl group-containing compound is extremely high. Therefore, in the chlorosilyl group-containing compound in the alcohol solvent, most of the chloro groups react with each other, resulting in (..Si-OR), (..Si-OH), (..Si-
O-Si ..) and (HCl). That is, the above-mentioned solution contains hydrochloric acid in addition to the silicon alkoxide or its hydrolyzate and the fluoroalkyl group-containing silane compound in the alcohol solvent. Also, when the solvent is a hydrophilic solvent other than alcohol,
The chloro group reacts with the water contained inevitably in the hydrophilic solvent, and as shown in formulas (15) and (18), (..Si
--OH), (..Si--O--Si ..), and (HCl).

Therefore, the highly reactive chloro group hardly remains, so that the pot life of the solution can be extended. Furthermore, since the influence of the humidity of the atmosphere during the work is less likely to occur, the management thereof becomes easy.

By the way, in the above solution, the formula (16)
Whether or not the hydrolysis reaction of (1) and the dehydration condensation reaction as shown in formula (18) are caused depend on the acid concentration of the solution, the concentration of the silicon alkoxide or its hydrolyzate, and the amount of water contained. It depends.

One of the features of the production method and the solution invention is that the silicon alkoxide in the solution is suppressed as the above-mentioned dehydration-condensation reaction and is kept as a monomer or a polymerization degree as low as possible. When this solution is applied to the surface of the substrate and dried, the formula (16) and the formula (1
Since the reaction of 8) is caused to form a siloxane bond, it is possible to form a dense film at room temperature.

Therefore, in the production method and the solution invention, it is desirable that the silicon alkoxide or its hydrolyzate in the solution is a monomer or a polymer of 19-mer or less. However, if the total ratio of the monomer, the hydrolyzate, and the polymer of 19-mer or less is 80% by weight or more based on the whole silicon alkoxide, the polymer of 20-mer or more is included. I don't care.

The acid in the solution will be described. For example, when 1% by weight of tetrachlorosilane is dissolved in an alcohol solvent, hydrochloric acid is produced by the reaction of formula (14). The acid concentration in the solution becomes about 0.2 N, and the pH of the solution becomes about 0.7. Therefore, when an alcohol solvent is used, hydrochloric acid is produced as described above, and therefore it is not particularly necessary to add and dissolve an acid.

When this hydrochloric acid is kept at a concentration of 0.001 to 3 N, the pH of the solution becomes 0 to 3 and the formula (16)
And the reaction of formula (18) becomes difficult to occur. as a result,
In the state of silicon alkoxide and its hydrolyzate,
The solution can be stably maintained for a long time.

The concentration of the acid catalyst in the solution was 0.001.
If it is less than the specified value or exceeds the specified value, the condensation reaction of the partial hydrolyzate of the silicon alkoxide in the solution is likely to occur, and the pot life of the solution is shortened. In addition, since the acid volatilizes and goes out of the film in the process of drying the coating film after applying the solution, it is necessary to maintain the acid concentration at a high level to some extent.

Therefore, the lower limit of the acid concentration is 0.001
The stipulation is essentially required, 0.01 s or more is more preferable, and 0.1 s or more is further preferable. On the other hand, the upper limit of the acid concentration is essentially 3 N or less, and more preferably 1 N or less. It should be noted that the above range may be exceeded if it is applied before the condensation reaction proceeds.

If the concentration of the acid in the solution is low due to a small amount of the chlorosilyl group-containing compound to be dissolved, it is possible to adjust the concentration of the acid in the solution by separately adding and dissolving the acid. desirable.

When another acid is added and dissolved, it is desirable to use an acid having a concentration of 0.3 times or more the water content. This is because if the acid used is a low concentration acid having a water content of less than 0.3 times, it will be difficult to maintain the pH of the solution at 3 or less. That is, when the acid in the form of an aqueous solution is used, it must be a highly concentrated acid having a concentration of 23.1% or more.

When the acid is used by being added and dissolved in the ethanol solvent, and the ethanol contains, for example, 0.5% by weight of water, the concentration of the acid in the solution is 0.15% by weight. It must be above.

When an acid is added, the kind is preferably a volatile acid such as hydrochloric acid, hydrofluoric acid, nitric acid or acetic acid from the viewpoint that it is volatilized by drying at room temperature and does not remain in the film. Among them, hydrochloric acid is particularly preferable because it has high volatility and is relatively safe to handle.

Further, the lower the concentration of the silicon alkoxide or its hydrolyzate and condensate in the solution, the less likely the reactions of the formulas (16) and (18) occur. Therefore, the total content of the chlorosilyl group-containing compound and the fluoroalkyl group-containing compound is preferably 10% by weight or less.

Further, when the water-repellent coating after coating and drying has a thickness of 5 nm or more and 200 nm or less, the durability of the coating can be improved. Therefore, the total concentration of the chlorosilyl group-containing compound and the fluoroalkyl group-containing compound varies depending on the coating method,
The appropriate amount is 0.01% by weight or more and 10% by weight or less. If the coating is applied before the condensation reaction proceeds, the above range may be exceeded.

If the total concentration of the chlorosilyl group-containing compound and the fluoroalkyl group-containing compound is lower than 0.01% by weight, the film thickness of the water-repellent coating after coating and drying will vary depending on the coating method. It becomes thinner than 5 nm. As a result, when the base material contains an alkaline component, the ability to prevent the diffusion of the alkaline component is almost lost, and the durability of the film is deteriorated.

On the other hand, when the concentration is higher than 10% by weight, the above-mentioned film thickness varies depending on the coating method.
m or more. In this case, the water-repellent coating is likely to be scratched, and a strong coating cannot be obtained.

Further, the concentration is more preferably 0.1% by weight or more and 5% by weight or less so as not to cause undesired coloring due to light interference. In terms of the film thickness of the film,
It is more preferably 10 nm or more and 100 nm or less.

Regarding the water content in the solution, the lower the water content, the less likely the reactions of the equations (16) and (18) occur. On the other hand,
The presence of a large amount of water in the solution accelerates the hydrolysis reaction of the partial hydrolyzate of the silicon alkoxide in the solution,
Moreover, the dehydration condensation reaction easily occurs. For this reason, the pot life of the solution is shortened, and unevenness in the film thickness is likely to occur during drying after the application of the solution.

Therefore, in order to prolong the pot life of the solution and to eliminate the unevenness of the film thickness during the drying after coating, it is preferable that the concentration of water in the solution is as small as possible. Therefore, the concentration of water in the solution is preferably 0 to 20% by weight, more preferably 0 to 10% by weight, and most preferably 0 to 2% by weight.

By maintaining and adjusting the concentration of water in the solution as described above, the reactions of the formulas (16) and (18) can be made difficult to occur.

Further, even if the concentration of water in the solution is zero, since the water in the air is absorbed by the coating film after being coated on the substrate, the hydrolysis reaction is not hindered. Absent.

In the case of a hydrophilic solvent, for example, an alcohol solvent usually inevitably contains some water, for example, by absorbing water in the air. As a result, the concentration of water in the solution becomes 0.1% by weight or more, so that it may not be necessary to add water.

When the above-mentioned solution is applied to the substrate, the solvent in the formed film evaporates, and the concentration of the silicon alkoxide or its hydrolyzate in the film suddenly rises. Reaction and dehydration condensation reaction (including further polycondensation reaction of the above-mentioned 19-mer or less polymer)
But it happens suddenly. That is, a siloxane bond (... Si-
A large number of O-Si ..) are formed in the film. As a result, it is possible to form a film containing silicon oxide as a main component, in which the bond between the surface of the base material and the water-repellent film is strong.

As described above, according to the production method of the present invention, the reactivity of hydrolysis and dehydration condensation at the time of forming a film is very high, so that the reaction is sufficient even at room temperature to form a very dense film. For this reason, the usual application does not require a subsequent firing step.

Next, the orientation of the fluoroalkyl group will be described. Alkoxy groups (or acyloxy groups, chlorine groups) in the fluoroalkyl group-containing silane compound in the solution undergo almost the same reaction as the above-mentioned silicon alkoxide. By the way, since the surface energy of the fluoroalkyl group is low, when the solution is applied, the fluoroalkylsilane component naturally moves to the outside of the formed film, and the fluoroalkyl group portion is directed to the outside of the film. Thus, the fluoroalkyl group-containing silane compound is oriented.

In the outer surface layer of the coating, the fluoroalkyl group is present in a higher concentration than in the inner layer of the coating. As the drying of the coating progresses, the fluoroalkyl group-containing silane compound remains in its orientation, the alkoxy group of the silicon alkoxide, and the alkoxy group (or the acyloxy group in the fluoroalkyl group-containing silane compound, The chlorine group is represented by the formula (16) and the formula (1
The reaction shown in 8) proceeds. Further, the fluoroalkyl group-containing silane compound is strongly bonded to the silicon alkoxide via the siloxane bond, and finally forms a gel layer of the fluoroalkylsilane-modified silanol polymer.

As the formed film was dried, a layer having silicon oxide as a main component strongly bonded was formed on the substrate, and a fluoroalkyl group was formed on the silicon oxide layer.
They are bonded at a high density and in a regularly oriented state.

In the production method invention, the fluoroalkyl group-containing silane compound is allowed to coexist with a silicon alkoxide in a solvent so that the compound represented by the formula (1)
6), a siloxane bond is formed with a silicon alkoxide through the reaction of formula (18), and the fluoroalkyl group, which is a water-repellent group at the time of film formation, is oriented so as to face the outside of the film. A film is formed.

In the production method invention, the acid concentration of the solution is increased in order to increase the reactivity during film formation. Therefore, it is possible to form a very dense film while forming a film at room temperature. Further, the reactions of the formulas (16) and (18), that is, the reaction in which the silicons of the silicon alkoxide form a siloxane bond, and the reaction between the silicon on the substrate surface and the silicon in the silicon alkoxide form a siloxane bond, The alkyl group-containing silane compound is
The reaction is more likely to occur than the reaction of forming a siloxane bond with a silicon alkoxide, and as a result, fluoroalkyl groups are likely to collect on the outermost surface of the coating. Therefore, the water-repellent coating has a high water-repellent group density on the outermost surface of the coating.

If the content of the fluoroalkyl group-containing silane compound with respect to the chlorosilyl group-containing compound in the solution is too small, the water repellent performance of the water repellent film is lowered, and if it is too large, the durability of the water repellent coating film is lowered. . Therefore, the solution, the ratio of the chlorosilyl group-containing compound and the fluoroalkyl group-containing silane compound, the number of silicon atoms in the chlorosilyl group-containing compound Si (Cl) and the number of silicon atoms in the fluoroalkyl group-containing silane compound Expressed as Si (F), it is preferable that Si (F) is contained in a ratio of 0.05 or more and 50.0 or less with respect to 100 of Si (Cl).
It is more preferably 0.05 or more and 30 or less, and most preferably 0.05 or more and 3 or less.

If the hydrolysis or polycondensation reaction proceeds in the above solution, a dense film cannot be obtained. In order to make the coating dense, a firing process at 250 ° C. for about 1 hour or more is required. Due to the temperature rise during the baking, the alkaline component in the substrate tends to diffuse into the film and hinder the water-repellent action of the fluoroalkyl group. But,
The coating film obtained by the present invention has sufficient denseness and basically does not require a firing step.

Further, in the present invention, in order to further increase the denseness of the water-repellent film, the water-repellent film-forming solution is applied to the surface of the substrate and dried at room temperature or 150 ° C. or lower, Or higher than that temperature without drying 30
It is also possible to fire at a temperature of 0 ° C. or lower. In this case, since the coating film before firing is sufficiently dense, the alkali component is unlikely to diffuse into the coating film and adversely affect the durability of the coating film.

Further, the water-repellent coating of the water-repellent article obtained by the present invention is characterized in that its surface is very smooth. The surface roughness characteristics of the water-repellent coating are arithmetic average roughness (Ra) = 0.5 nm or less and ten-point average roughness (Rz) = 5 nm or less. The surface roughness characteristics Ra and Rz are defined by two-dimensional JIS B 060.
It can be measured by a method in which 1-1982 is expanded in three dimensions.

One of the reasons why the water-repellent coating has excellent water droplet rolling property and scratch resistance is considered to be the above-mentioned surface smoothness. The reason why this smoothness is obtained is as follows. In the solution,
Since the silicon alkoxide and the fluoroalkyl group-containing silane compound, especially the silicon alkoxide, exist as a monomer (including a hydrolyzate) or a polymer of 19-mer or less, it is possible to uniformly dissolve the solvent. Become. Therefore, a uniform film thickness can be obtained by applying the solution onto the surface of the base material.

When the applied film is further dried, the film-forming reaction rapidly progresses in a short time while maintaining a uniform film thickness. As a result, a film having excellent smoothness is formed. become.

Further, in the present invention, since the water-repellent group is naturally oriented at the time of film formation, the water-repellent layer having a better orientation than the conventional water-repellent treatment such as chemical adsorption or hand-coating afterwards. It is believed that can be formed. Therefore, according to the present invention, the water-repellent film surface has a high water-repellent group density, the orientation of the water-repellent group is excellent, and the effect of the smoothness of the surface is combined, resulting in excellent water drop rolling property and weather resistance, Abrasion resistance is obtained.

In the solution of the present invention, the fluoroalkyl group-containing silane compound is added to a solvent containing alcohol and / or water, the mixture is stirred for 10 to 60 minutes, and then the chlorosilyl group-containing compound is added to the solution.
Prepared by stirring for minutes. The life of this solution is very long. However, if the amount of acid is relatively small or large, or if the amount of chlorosilyl group-containing compound or water is large, hydrolysis or polycondensation reaction may proceed in the solution. Treatment is preferable. A water-repellent article is obtained by applying the solution prepared as described above to the surface of the substrate and then drying at room temperature for 10 seconds to 10 minutes to evaporate the solvent.

Further, in the present invention, since the water-repellent group is naturally oriented at the time of forming the coating film, the method of applying the solution is as follows.
A method capable of slowly drying the coating film to some extent is preferable. Examples thereof include dip coating, flow coating, curtain coating, spin coating, spray coating, bar coating, roll coating and brush coating.

Therefore, it is possible to obtain a water-repellent article on which a water-repellent film having a high density of the formed film and having excellent surface smoothness, water-repellent group density and orientation of the water-repellent group is formed. Becomes Further, the water repellent article according to the present invention,
It has excellent water rollability and high scratch resistance and weather resistance.

As the base material used in the present invention, a base material having a hydrophilic group on its surface is used. Specific examples include glass, ceramics, plastics, and metals. If there are few hydrophilic groups on the surface of these base materials, the surface is treated in advance with oxygen-containing plasma or corona atmosphere to make them hydrophilic, or the base material surface is exposed to oxygen-containing atmosphere. 200-300n
It is preferable to apply the present invention after irradiating with an ultraviolet ray having a wavelength near m to perform a hydrophilic treatment.

Embodiments of the present invention will be described below. [Example 1] 100 g of ethanol (water content 0.3
To 5 wt%), 3-heptadecafluorodecyltrimethoxysilane _{(CF 3 (CF 2) 7} (CH 2) 2 Si (OC
H _{3) 3,} was added Etsu Silicone) 0.02 g, 3
Stir for 0 minutes, then tetrachlorosilane (SiC
l _4, was added with stirring Etsu Silicone) 1.0 g, was obtained for forming a water-repellent film solution. This solution is Si (C
l) Si (F) is contained in a ratio of 0.6 to 100, has a hydrochloric acid concentration of about 0.2 N and a water concentration of 0.35% by weight, and has a pH of about 0.7. Had.

Further, this solution was measured using a Fourier transform nuclear magnetic resonance apparatus (FT-NMR: "EX270" manufactured by JEOL Ltd.) to find out the presence of tetraethoxysilane (and its (partial) hydrolyzate). Absorption peak at chemical shift of -82 ppm, and chemical shift at -96 ppm showing the presence of trimer of tetraethoxysilane.
Was observed, and an absorption peak indicating the presence of a tetramer or higher polymer was not detected.

A glass substrate washed with this solution (150 ×
(150 mm) on the surface of which the humidity was 30% at room temperature and was applied by a flow coating method, and dried at room temperature for about 1 minute to obtain a water-repellent glass plate. Table 1 shows the ratio of Si (F) to Si (Cl) 100, the normality of hydrochloric acid, the water content (wt%), the pH of the solution, and the polymerization degree of the polymer.

With respect to the obtained water-repellent glass plate, the contact angle of water was measured by a contact angle meter (CA-DT, manufactured by Kyowa Interface Science Co., Ltd.).
Was measured as a static contact angle (hereinafter, sometimes referred to as CA) by a water drop having a weight of 2 mg. The larger the contact angle, the better the static water repellency.

As a measure of the ability of water droplets to roll on the surface of the water-repellent glass plate, water droplets having a diameter of 5 mm are placed on the surface of the horizontally arranged water-repellent glass plate, and the water-repellent glass plate is gradually inclined, The inclination angle of the glass plate (critical inclination angle, hereinafter referred to as IA) when water drops placed on the surface start rolling.
In some cases) was measured. The smaller the IA is, the more excellent the dynamic water repellency is, and it means that, for example, raindrops attached to the windshield window of a running automobile are easily scattered, and the driver's view is not obstructed.

The smoothness of the obtained water-repellent glass is
Atomic force microscope (AFM) (Seiko Denshi Kogyo Co., Ltd.)
Manufactured by Scanning Probe Microscope "SPI3700", cantilever; silicon "SI-DF20"), using a sample measuring area of 1 μm × 1 μm square with 512 measurement points.
× 256 points, scan speed 1.02Hz, DFM
Measure the surface shape in (Cyclic contact mode), correct by low-pass filter and leveling correction of measured data (a curved surface is obtained by least square approximation and fitting is performed, the inclination of the data is corrected, and the distortion in the Z-axis direction is also corrected. Was removed) and the surface roughness Ra and the Rz value were calculated.

Further, the fluorine concentration on the surface of the obtained water-repellent glass coating was determined as the atomic ratio of F / Si on the surface of the coating using X-ray photoelectron spectroscopy (5600 Ci, manufactured by ULVAC-PHI). The measurement conditions for X-ray photoelectron spectroscopy are:
The test conditions of X-ray photoelectron spectroscopy (ESCA) are as follows: monochromatic aluminum Kα ray is used as an X-ray source.
Anode energy: 1486.6 eV, anode output: 150 W, accelerating voltage: 14 kV, X-ray incident angle on the sample: 45 degrees, analysis area: diameter 800 μm circle, measurement thickness: several nm.

Next, as a weather resistance test, an ultraviolet resistance tester (“I Super UV Tester W-13”, manufactured by Iwasaki Electric) was used to adjust the ultraviolet light intensity to 76 ± ² mW / cm ² ,
Black panel temperature 48 ± 2 ℃, irradiation 20 hours, darkness 4
In the cycle of time, ultraviolet rays were irradiated for 400 hours under the condition of showering with ion-exchanged water for 30 seconds every hour. Then, after irradiation, CA and IA of water were measured.

As a friction resistance test, a reciprocating wear tester (manufactured by Shinto Kagaku Co., Ltd.) was attached with a dry cloth, and a load of 0.3 was applied.
The surface of the water-repellent film was slid back and forth 3000 times under the condition of kg / cm ² , and then CA and IA of water were measured. The thickness of the water repellent film was measured by a transmission electron microscope. Water-repellent film thickness, initial CA and IA, film surface fluorine concentration F /
Si value, surface roughness Ra, Rz value, CA after weather resistance test
Table 2 shows the measurement results of IA and IA, and CA and IA after the abrasion resistance test.

Example 2 The water-repellent glass plate obtained in Example 1 was further fired at 250 ° C. for 1 hour to obtain a water-repellent glass. The results measured in the same manner as in Example 1 are shown in Tables 1 and 2.

[Examples 3 and 4] Except that 0.005 g and 0.05 g of 3-heptadecafluorodecyltrimethoxysilane were added in the preparation of the water-repellent film forming solution,
A water-repellent glass plate was obtained in the same manner as in Example 1. The cases where the added amounts of 3-heptadecafluorodecyltrimethoxysilane are 0.005 g and 0.05 g are set as Example 3 and Example 4, respectively. In addition, this solution was prepared by adding tetrachlorosilane and 3-heptadecafluorodecyltrimethoxysilane to Si (Cl) 100 in an amount of 0.1% Si (F).
It was contained in a ratio of 5 (Example 3) and 1.5 (Example 4). The results measured in the same manner as in Example 1 are shown in Tables 1 and 2.

[Examples 5 and 6] In the preparation of the water-repellent film forming solution, 0.5 g or 2.0 instead of 1.0 g of tetrachlorosilane added in Example 1 was used.
A glass plate with a water-repellent coating was obtained in the same manner as in Example 1 except that g was added. The amount of tetrachlorosilane added was 0.
Let 5 g and 2.0 g glass plates be Example 5 and Example 6, respectively. In addition, this solution was prepared by adding tetrachlorosilane and 3-heptadecafluorodecyltrimethoxysilane to Si (Cl) 100 with Si (F) of 1.2 (Example 5) and 0.3 (Example 6). It was contained in proportion.
The results measured in the same manner as in Example 1 are shown in Tables 1 and 2.

Example 7 To 100 g of ethanol (water content 0.35% by weight), 0.1 g of 3-heptadecafluorodecyltrimethoxysilane was added, stirred for 30 minutes, and then 5.0 g of tetrachlorosilane was added. It was added with stirring to obtain a solution for forming a water-repellent film. This solution was prepared by adding tetrachlorosilane and 3-heptadecafluorodecyltrimethoxysilane to Si (Cl) 100 and Si.
The content of (F) was 0.6. Clean the glass substrate (150 x 150 mm) at 30% humidity and room temperature,
A glass plate with a water-repellent coating was obtained by immersing in the above solution, pulling it up at a rate of 10 cm / min by a dipping method, and drying at room temperature for about 1 minute. The results measured in the same manner as in Example 1 are shown in Tables 1 and 2.

Example 8 Instead of adding 0.02 g of 3-heptadecafluorodecyltrimethoxysilane in the preparation of the solution of Example 1, 3-heptadecafluorodecyltrichlorosilane (CF ₃ (CF ₂ )) was added. ₇ (C
A glass plate with a water-repellent coating was obtained in the same manner as in Example 1 except that 0.02 g of H ₂ ) ₂ SiCl ₃ ) was added. This solution contained tetrachlorosilane and 3-heptadecafluorodecyltrichlorosilane in a ratio of Si (F) of 0.6 with respect to 100 of Si (Cl). Example 1
The results measured in the same manner as in are shown in Tables 1 and 2.

Example 9 To 100 g of ethanol (water content 0.35% by weight) was added 3-heptadecafluorodecyltrimethoxysilane (CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂
Add 0.02 g of Si (OCH ₃ ) _{3 ,} manufactured by Shin-Etsu Silicone and stir for 30 minutes, then add 0.3 g of tetrachlorosilane (SiCl ₄ , manufactured by Shin-Etsu Silicone) while stirring, and then add concentrated hydrochloric acid (35 wt. %, Manufactured by Kanto Chemical)
2 g was added with stirring to obtain a water-repellent film forming solution. This solution was prepared by adding tetrachlorosilane and 3-heptadecafluorodecyltrimethoxysilane to Si (Cl) 100
On the other hand, Si (F) was contained in a ratio of 2.0. This solution was applied on the surface of a washed glass substrate (150 × 150 mm) by a flow coating method at a humidity of 30% at room temperature and dried at room temperature for about 1 minute to obtain a glass plate with a water-repellent coating. The results measured in the same manner as in Example 1 are shown in Tables 1 and 2.

[Embodiment 10] In the preparation of the water-repellent film forming solution of Embodiment 1, ethanol (containing water content 0.3
5% by weight) 100 g instead of ethanol (containing water content 0.35% by weight) 90 g and isoparaffinic hydrocarbon solvent (ISOPAR L, exxon) 10 g, except that water repellent coating film was prepared in the same manner as in Example 1. The attached glass plate was obtained. The composition of the solution for forming the water-repellent film is shown in Table 1, and the results measured in the same manner as in Example 1 are shown in Tables 1 and 2.

[Embodiment 11] In the preparation of the solution for forming the water-repellent coating of Embodiment 1, ethanol (containing water content: 0.3
A glass plate with a water-repellent coating was obtained in the same manner as in Example 1 except that 90 g of ethanol and 10 g of water were used instead of 100 g of (5% by weight). The composition of the solution for forming the water-repellent film is shown in Table 1, and the results measured in the same manner as in Example 1 are shown in Tables 1 and 2.

[Embodiment 12] In the preparation of the water-repellent film forming solution of Embodiment 1, the addition amount of tetrachlorosilane was 1.
A glass plate with a water-repellent coating was obtained in the same manner as in Example 1 except that 0.05 g was used instead of 0 g. The composition of the solution for forming the water-repellent film is shown in Table 1, and the results measured in the same manner as in Example 1 are shown in Tables 1 and 2.

The glass plates with water-repellent coatings obtained in Examples 1 to 12 above showed an initial CA of 100 ° C. or higher and an initial IA of 9 ° C. or lower, and were found to have excellent water repellency. Although the water repellency after the weather resistance test is slightly reduced,
CA is 80 degrees or more, and CA after the abrasion resistance test is 98.
It was found to be excellent and durable.

The water-repellent film has a thickness of 5 to 100 nm, and the surface roughness of the film is such that Ra is 0.5 nm or less and Rz =
It was 5 nm or less, and it was confirmed that the smoothness of the surface of the water-repellent coating was excellent.

Further, with respect to the fluorine concentration on the surface of the coating film, F / Si of F was 0.8 or more because the above-mentioned hydrolyzate and dehydration condensation reaction in the solution were suppressed. It was also confirmed that a large amount of fluoroalkyl groups were present in the outer surface layer of the water-repellent coating, and the inner layer was substantially composed of silicon oxide.

The solutions for forming the water-repellent coating used in the above examples could be applied without gelation.

[Comparative Example 1] Ethanol (containing water content: 0.
35 wt%) To 81.2 g, tetraethoxysilane 9.5 g and 3-heptadecafluorodecyltrimethoxysilane 0.26 g were added, stirred for 30 minutes, and then 4.04 g of water and 5.0 g of 0.1N hydrochloric acid. Was added, and the mixture was stirred for 10 days and diluted 5-fold with ethanol to obtain a water-repellent film-forming solution. A glass substrate (150 x
150 mm) at 30% humidity and room temperature by flow coating, dried and baked at 250 ° C. for 1 hour to obtain a glass plate with a water-repellent coating. The results are shown in Tables 1 and 2.

With respect to Si (F) in Comparative Example 1 and Comparative Example 2 in Table 1, the number of silicon atoms in the fluoroalkyl group-containing silane compound is 100 when the number of silicon atoms in tetraethoxysilane is 100. Is the ratio of.

This Comparative Example 1 is an example in which the content of hydrochloric acid is smaller than that in the above Examples. In this example, the hydrolyzate and dehydration condensation reaction of the silicon alkoxide and the fluoroalkyl group-containing silane compound proceeded in the solution. It should be noted that Comparative Example 1 and Comparative Example 2 below are additional tests of the above-mentioned JP-A-4-338137.

[Comparative Example 2] Ethanol (containing water content: 0.
35% by weight) 85.3 g of tetraethoxysilane
40 g and 1.92 g of 3-heptadecafluorodecyltrimethoxysilane were added and stirred for 20 minutes, then 16.6 g of water and 20.8 g of 0.1N hydrochloric acid were added and stirred for 2 hours, which was placed in a closed container. After standing at 25 ° C. for 24 hours, a water-repellent film forming solution was obtained. This solution contains
It contained a 30-mer of tetraethoxysilane. A washed glass substrate (150 x 150 mm) is dipped in this solution, coated by dipping, dried and then at 250 ° C for 1 hour.
Firing was carried out for a time to obtain a glass plate with a water-repellent coating. The results are shown in Tables 1 and 2.

The comparative example 2 is an example in which the water content is higher than that in the above-mentioned examples. In this example, the hydrolyzate and dehydration condensation reaction of the silicon alkoxide and the fluoroalkyl group-containing silane compound proceeded in the solution.

[Comparative Example 3] CF ₃ was used as a fluorocarbon solvent.
1 g of tetrachlorosilane and 1 g of 3-heptadecafluorodecyltrichlorosilane were added to 40 g of CF ₂ CHCl ₂ (Asahiclin AK-225, manufactured by Asahi Glass Co., Ltd.), and 3
The solution was stirred for 0 minutes to obtain a water-repellent film forming solution. This solution was applied onto a washed glass substrate (150 x 150 mm) with a cotton pad at room temperature and humidity of 30%, and after drying,
After baking at 3 ° C. for 1 hour, excess silane was removed from the glass surface by solvent washing after baking to obtain a glass plate with a water-repellent coating. The results are shown in Tables 1 and 2. It should be noted that Comparative Example 3 and Comparative Example 4 below are described in the above-mentioned JP-A-8-239.
It is an additional test of No. 653.

[Comparative Example 4] To 79.24 g of an isoparaffin hydrocarbon solvent (ISOPAR L, manufactured by Exxon), 0.36 g of tetrachlorosilane and 0.4 g of 3-heptadecafluorodecyltrichlorosilane were added, and the mixture was stirred for 30 minutes. Thus, a solution for forming a water-repellent film was obtained. A glass substrate (150 x 150 mm) on which this solution was washed had a humidity of 30
%, By flow coating at room temperature, and after drying, excess silane was removed from the glass surface by solvent washing to obtain a glass plate with a water-repellent coating. The results are shown in Tables 1 and 2.

The results are shown in Tables 1 and 2 as follows.
All the water-repellent glass plates obtained in Comparative Examples 1 to 4 were
Initial CA is better than 101 degrees, but IA
Was 15 degrees or more, which was higher than that of the example, and the rolling property was poor.

Regarding the smoothness of the surface of the obtained water-repellent coating film, although Comparative Examples 1 and 2 are relatively excellent,
Comparative Examples 3 and 4 were inferior in smoothness.

Further, regarding the weather resistance test, both CA and IA in Comparative Examples 1 and 2 were inferior to those in the Examples. In Comparative Examples 3 and 4, CA was equivalent to that of Example, but IA was inferior.

Further, in the wear resistance test, both Comparative Examples were inferior in CA and IA as compared with the Examples.

Regarding the fluorine concentration on the coating surface, in the above-mentioned Comparative Examples 1 and 2, since the above-mentioned hydrolyzate and dehydration condensation reaction proceeded in the solution, the F / S
It was as low as i = 0.5 and 0.6, and it was confirmed that there were few fluoroalkyl groups. Fluorine was also detected in the inner layer of the coating.

From the above, it was confirmed that the water-repellent article obtained by the present invention has a very high fluorine concentration on the surface of the water-repellent film.

[0150]

[Table 1] ============================= Sample Si (F) ^* HCl Moisture pH pH (N) of polymer (wt) %) Degree of polymerization −−−−−−−−−−−−−−−−−−−−−−−−−−−−− Actual 1 0.6 0.19 0.35 0.73 1 to 3 Actual 3 0.15 0.19 0.35 0.73 1 to 3 Actual 4 1.5 0.19 0.35 0.73 1 to 3 Actual 5 1.2 0.09 0.35 1.03 1 to 3 Actual 6 0.3 0.37 0.34 0.43 1 to 3 Actual 7 0.6 0.92 0.33 0.04 1 to 10 Actual 8 0.6 0.19 0.35 0.73 1 to 3 Actual 9 2.0 0.21 1.61 0.68 1 to 3 Actual 10 0.6 0.19 0.31 0.73 1 to 3 Actual 11 0.6 0.19 10.23 0.72 1 to 5 Actual 12 12.0 0.009 0.35 2.03 1 to 3 −−−−−−−−−−−−−−−−−−− −−−−−−−−−−− Ratio 1 1.0 0.008 2.14 3.09 4 to 30 Ratio 2 1.8 0.014 22.8 1.86 4 to 30 Ratio 3 29.3 ---- --1 Ratio 4 32.4 ---- --1 = ============================ * Si (F) is the ratio of Si (F) to Si (Cl) 100. Indicates the rate.

[0151]

[Table 2] ====================================                  Initial surface roughness Weather resistance test Abrasion resistance test sample   Thickness CA IA F / Si Ra Rz CA IA CA IA        (nm) (degree) (degree) (atomic ratio) (nm) (nm) (degree) (degree) (degree) (degree) −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Actual 1 60 111 5 1.2 0.4 2.9 83 20 106 8 Actual 2 60 110 6 1.1 0.4 3.8 85 18 107 9 Actual 3 60 104 9 0.8 0.3 2.8 80 21 103 10 Actual 4 60 111 5 1.3 0.3 3.1 85 19 99 10 Actual 5 30 110 6 1.1 0.5 4.6 80 22 98 12 Actual 6 100 109 6 1.0 0.2 1.8 88 17 105 9 Actual 7 80 111 4 1.3 0.3 2.6 87 17 106 8 Actual 8 60 111 5 1.2 0.4 3.3 84 19 105 10 Actual 9 20 110 5 1.2 0.5 4.8 82 20 98 11 Actual 10 60 110 6 1.2 0.4 4.2 84 19 104 10 Actual 11 60 109 6 1.2 0.4 4.3 80 20 105 9 Actual 12 5 106 8 1.0 0.5 4.7 86 18 98 11 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Ratio 1 60 101 15 0.5 0.3 6.2 65 35 96 18 Ratio 2 100 102 18 0.6 0.6 8.6 67 38 97 20 Ratio 3 10 112 34 1.3 7.9 29.8 85 33 71 39 Ratio 4 10 110 18 1.1 3.2 19.3 83 22 38 46 ====================================

[0152]

As described above, according to the present invention,
An article coated with a dense and strong water-repellent film can be obtained even after treatment at room temperature. In the present invention, it is basically unnecessary to perform baking after forming the water repellent film. As a result, no firing equipment is required and the manufacturing cost is reduced.

Further, since the fluoroalkyl group-containing silane compound serving as a water-repellent group is added to the water-repellent film-forming solution, the silica-based layer and the repellant agent can be repelled by coating only one kind of solution. A water layer can be formed. Therefore, the productivity is excellent.

Further, since the silica content is easily collected on the surface of the base material during the formation of the coating film, while the water-repellent group is easily oriented on the outermost surface of the coating film, the outermost surface has a high water-repellent group density, is dense and is excellent in durability. A water repellent film can be obtained.

Since a dense water-repellent film is formed at room temperature, the surface of the film becomes a water-repellent film having extremely excellent smoothness. Due to the effects of the good orientation and surface smoothness of the water-repellent group and the high density of the water-repellent group on the outermost surface, the water-repellent article of the present invention has very excellent water drop rolling property, scratch resistance, and weather resistance. Made possible

Furthermore, the production method and the water-repellent film forming solution of the present invention make it easy to control the humidity of the atmosphere during storage and coating operations.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Sunada             3-5-11 Doshomachi, Chuo-ku, Osaka-shi, Osaka Prefecture               Within Nippon Sheet Glass Co., Ltd. F-term (reference) 4H020 BA36                 4J038 DL071 JA16 JC31 MA07                       NA07 PC03 PC08

Claims (7)

[Claims] 1. A solution obtained by dissolving a chlorosilyl group-containing compound and a fluoroalkyl group-containing silane compound in a solvent containing alcohol and / or water and substituting the chloro group of the chlorosilyl group-containing compound with an alkoxyl group or a hydroxyl group. A method for producing a water-repellent article, which comprises the step of applying a water-repellent coating on the surface of a material and then drying it to form a water-repellent coating. 2. A solution containing a silicon alkoxide or a hydrolyzate thereof in the form of a monomer or a polymer of 19-mer or less, and further coating a solution containing a fluoroalkyl group-containing silane compound and an acid on the surface of a substrate. A method for producing a water-repellent article, which comprises a step of drying to form a water-repellent coating. 3. A water-repellent article obtained by the method according to claim 1, wherein the surface of the water-repellent coating has an arithmetic average roughness (Ra) = 0.5.
A water-repellent article having a roughness of not more than 10 nm and a ten-point average roughness (Rz) of not more than 5 nm. 4. The water-repellent article obtained by the method according to claim 1, wherein the fluorine concentration on the surface of the water-repellent coating is 0.8 or more in terms of an atomic ratio of fluorine atoms and silicon atoms. Is a water repellent article. 5. A method in which a chlorosilyl group-containing compound and a fluoroalkyl group-containing silane compound are dissolved in a solvent containing alcohol and / or water to replace the chloro group of the chlorosilyl group-containing compound with an alkoxyl group or a hydroxyl group. A characteristic water-repellent film forming solution. 6. A water-repellent coating film comprising a silicon alkoxide or a hydrolyzate thereof as a monomer or a polymer of 19-mer or less and further containing a fluoroalkyl group-containing silane compound and an acid. solution. 7. A chlorosilyl group-containing compound and a fluoroalkyl group-containing silane compound are dissolved in a solvent containing alcohol and / or water, and the chloro group of the chlorosilyl group-containing compound is substituted with an alkoxyl group or a hydroxyl group to give silicon. A solution for forming a water-repellent film, characterized in that the alkoxide or its hydrolyzate is contained as a monomer or a polymer of 19-mer or less.