JPH08325037A - Water- and oil-repellent antifouling glass and method for producing the same - Google Patents

Abstract

(57) [Abstract] [Purpose] After forming an alkali barrier layer 2 containing no alkali metal or a small alkali metal content in the vicinity of the surface of the glass substrate 1, a surfactant molecule is formed on the glass surface by covalent bonding. By providing the chemical adsorption film 3, a water- and oil-repellent antifouling glass having excellent durability is provided. [Structure] A soda-lime glass substrate 1 is prepared, and first dealkalized with a sulfuric acid aqueous solution. For example, 10% concentrated sulfuric acid in water
Dip the glass substrate in an aqueous solution diluted to about 90 to 90
Treat at 8 ° C for about 5 hours. By this treatment, the alkaline component is eluted and the alkaline barrier layer 2 can be formed. Next, CF is used as a fluorosilane-based surfactant for chemical adsorption.
_The soda lime glass substrate 1 is immersed in a solution of ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ SiCl ₃ dissolved in a non-aqueous solvent. After that, unreacted substances are removed with a non-aqueous solution and reacted with water to obtain a water-repellent, oil-repellent, and antifouling glass having a chemical adsorption film 3 composed of a single molecule.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water / oil repellent antifouling glass and a method for producing the same. For more information,
The present invention relates to a highly durable water-repellent, oil-repellent, and antifouling glass used for windows, mirrors, and glass containers and glasses used for vehicles such as buildings, automobiles, trains, and planes,
A highly durable glass excellent in water repellency, oil repellency and antifouling property, which has a layer containing no alkali or a small alkali content in the vicinity of the surface and has a chemical adsorption film made of a surfactant bonded to the layer It is a thing.

[0002]

2. Description of the Related Art As a method for improving the water and oil repellency of a glass surface, a method of coating and baking a fluoropolymer on the surface of a glass substrate or forming a fluorocarbon-based chemisorption monomolecular film has been proposed. In particular, the latter method of forming a fluorocarbon-based chemisorption monomolecular film has been proposed by the present inventors (JP-A-4-13).
2637, Japanese Patent Laid-Open No. 4-221630, Japanese Patent Laid-Open No. 4-377721, etc.).

[0003]

However, while the above-mentioned coating method by baking is easy to manufacture, there is a limit to improving the adhesion between the glass surface and the coating film because the glass is an immovable body. However, peeling of the film occurred and a coating film with good durability could not be obtained.

On the other hand, in the method of forming a fluorocarbon-based chemisorption monomolecular film, durability against peeling of the film is obtained, but there is a problem that heat resistance, water resistance and weather resistance are poor. Examination of the cause revealed that the cause is an alkali metal component such as sodium contained in the glass substrate. That is, the conventional fluorocarbon-based chemisorption monolayer has a problem of alkali resistance.

In order to solve the above-mentioned conventional problems, the present invention improves the durability of chemical adsorption that has been deteriorated or decomposed due to the alkaline component contained in the glass substrate, that is, heat resistance, water resistance and weather resistance. The purpose is to do.

[0006]

In order to achieve the above object, the water-repellent, oil-repellent, and antifouling glass of the present invention has a water-repellent film having a chemisorption film made of surfactant molecules formed by covalent bonds on the glass surface. An oil-repellent antifouling glass, characterized in that an alkali barrier layer containing no alkali metal or having a small alkali metal content is provided near the glass surface.

In the above constitution, it is preferable that the surfactant molecule contains a fluorocarbon group. This is because it is excellent in water and oil repellency and stain resistance. Further, in the above structure, it is preferable that the chemisorption film composed of the surfactant molecule is covalently bonded to the surface of the base material via the SiO group. This is because the SiO group remains due to the dehydrochlorination reaction between the chlorosilyl group of the surfactant and the hydrophilic group such as the hydroxyl group on the surface of the glass substrate. Further, since the SiO group is easily hydrolyzed by an alkali metal, it is particularly meaningful to form a layer containing no alkali metal or a small alkali metal content in the vicinity of the glass surface.

Further, in the above constitution, it is preferable that the chemisorption film made of the surfactant molecule is covalently bonded to the surface of the substrate through the TiO group. This is because the TiO group remains due to the dehydrochlorination reaction between the chlorotitanyl group of the surfactant and the hydrophilic group such as the hydroxyl group on the surface of the glass substrate.
Also in the TiO group, it is particularly meaningful to form a layer containing no alkali metal or a small alkali metal content in the vicinity of the glass surface.

Further, in the above structure, it is preferable that the alkali metal concentration of the alkali barrier layer near the glass surface is 0.1% by weight or less. This is because the durability is improved.

Next, in the method for producing a water-repellent, oil-repellent, and antifouling glass of the present invention, a surfactant having a functional group that undergoes a condensation reaction with a hydrophilic group on the surface of the glass substrate is brought into contact with the glass substrate, and the glass is A method for producing a water / oil repellent / antifouling glass, which comprises causing a condensation reaction between a hydrophilic group on the surface of a base material and a functional group of the surfactant to chemically adsorb the surfactant, the method comprising: Prior to this, an alkali barrier layer containing no alkali metal or containing a small amount of alkali metal is formed in the vicinity of the glass surface in advance.

In the above-mentioned constitution, the method for forming a layer containing no alkali metal or containing a small amount of alkali metal is to treat the surface of the glass substrate with a dealkalizing metal, or to treat the surface of the glass substrate with an alkali. A method of forming a layer having a composition containing no metal or having a small alkali metal content is preferable.

Further, in the above structure, the dealkalizing metal treatment is preferably a contact treatment of the surface of the glass substrate with a mineral acid. Further, in the above structure, the mineral acid is preferably at least one acid selected from sulfuric acid, fuming sulfuric acid, hydrochloric acid, nitric acid, nitrous acid, phosphoric acid, and phosphorous acid.

Further, in the above-mentioned constitution, it is preferable that the contact treatment of the mineral acid is a method of treating with mineral acid-containing water or warm water, or bringing it into contact with a gas of the mineral acid. When the mineral acid is a liquid, it is preferably used as an aqueous solution, and when the mineral acid is a gas (for example, fuming sulfuric acid), a gas contact method is preferred.

In the above construction, the method of forming an alkali barrier layer containing no alkali or a small alkali content preferably forms a coating film containing silica on the surface of the glass substrate.

In the above structure, the method of forming a film containing silica is CVD (chemical vapor deposit).
Method or sol-gel method is preferably used. Further, in the above structure, it is preferable to use a fluorosilane-based surfactant having a fluorocarbon group and a chlorosilyl group or an alkoxy group as the surfactant.

Further, in the above constitution, the surfactant is
It is preferable to use a fluorotitanium-based surfactant having a fluorocarbon group and a titanate group. Further, in the above constitution, the fluorosilane-based surfactant is preferably at least one selected from the above formulas (Formula 1) and (Formula 2).

Further, in the above constitution, the chemical adsorption treatment is a treatment in which the glass substrate is immersed in a solution in which the surfactant is dissolved in a non-aqueous solvent, or the glass substrate is exposed to a gas atmosphere of the surfactant. Is preferred.

In the above structure, it is preferable that the glass substrate is immersed in a solution in which a surfactant is dissolved in a non-aqueous solvent for chemical adsorption treatment, and then the unreacted surfactant is washed and removed with a non-aqueous solution. .

[0019]

According to the water- and oil-repellent antifouling glass of the present invention described above, a water- and oil-repellent antifouling glass having a chemical adsorption film of surfactant molecules formed on the glass surface by covalent bonding, The vicinity of the glass surface is provided with an alkali barrier layer containing no alkali metal or a small alkali metal content, so that the chemical adsorption durability was deteriorated or decomposed due to the alkali component contained in the glass substrate. That is, heat resistance, water resistance, and weather resistance can be improved. That is, alkaline hydrolysis of the chemisorption film can be prevented by removing or reducing the amount of the alkali metal component.

Next, according to the method for producing a water-repellent, oil-repellent and antifouling glass of the present invention, a surfactant having a functional group that undergoes a condensation reaction with a hydrophilic group on the surface of the glass substrate is brought into contact with the glass substrate,
A method for producing a water- and oil-repellent antifouling glass in which a condensation reaction is caused between a hydrophilic group on the surface of the glass substrate and a functional group of the surfactant, and the surfactant is chemically adsorbed, The water- and oil-repellent antifouling glass of the present invention can be efficiently and reasonably formed by forming an alkali barrier layer containing no alkali metal or a small alkali metal content in the vicinity of the glass surface in advance before chemisorption. Can be manufactured.

As described above, a layer containing no alkali or a small amount of alkali is formed on the surface of the glass base material, and the base material is contacted with a chemical adsorbent solution in which a surfactant is dissolved in a non-aqueous solvent. A water-repellent and oil-repellent having excellent durability by chemically adsorbing the surfactant on the surface of the alkali barrier layer containing no alkali or having a small alkali content to form a water-repellent and oil-repellent antifouling film. Antifouling glass can be realized.

[0022]

EXAMPLES Hereinafter, with reference to FIG. 1, a step of forming a layer containing no alkali or a small alkali content on the surface of a glass substrate, and a chemistry in which a surfactant is dissolved in a non-aqueous solvent will be described. A method for producing a water- and oil-repellent antifouling glass by using a step of bringing a substrate into contact with an adsorbent and chemically adsorbing the surfactant on the surface of the alkali barrier layer containing no alkali or having a small alkali content will be described. To do. In the following examples,% means% by weight unless otherwise specified.

(Example 1) A soda-lime glass substrate 1 (a white plate, colored glass, etc. can be similarly used) prepared as a window glass for a high-rise building that has been reinforced by air cooling is prepared in advance and dealkalized with an aqueous sulfuric acid solution. To process. For example, the glass substrate is immersed in an aqueous solution of concentrated sulfuric acid diluted with water to about 10% and treated at 90 to 98 ° C for about 5 hours (in addition to sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, organic acid, etc. can be used. However, it is convenient because sulfuric acid has a low vapor pressure even when the temperature is high and it can be used stably. After that, if you wash it well with water,
As shown in (a), the vicinity of the surface of the glass substrate 1 is about 1 μm
(Alkali components) such as sodium and potassium were eluted in a certain region, and a layer 2 (which functions as an alkali barrier layer) containing almost no alkali was formed on the surface.

Next, a compound represented by the following formula (Formula 3) was used as a fluorosilane-based surfactant containing a fluorocarbon group for chemisorption and a chlorosilyl group.

[0025]

Embedded image

The compound represented by the above formula (Formula 3) was added in an amount of 3 × 1 in a dry atmosphere, for example, an air atmosphere having a relative humidity of 10% or less.
A chemisorption solution was prepared by dissolving it in a non-aqueous solvent at a concentration of about 0 ^-3 Mol / L. As the non-aqueous solvent, 80% n-hexadecane, 12% carbon tetrachloride and 8% chloroform solution were used. The glass substrate 1 was immersed in the chemical adsorption solution at room temperature for 1 hour. By this dipping treatment, since the surface of the layer 2 containing almost no alkali on the surface of the substrate 1 contains a large number of hydroxyl groups, the chlorosilyl group and the hydroxyl group of the chlorosilane-based surfactant represented by the above formula (Formula 3) are represented by the following formula As shown in 4), dehydrochlorination reaction (called chemisorption) was performed.

[0027]

[Chemical 4]

Then, it was thoroughly washed with a non-aqueous solution such as chloroform to remove the unreacted chlorosilane-based surfactant represented by the above formula (Formula 3). Next, when exposed to air to react with water or with fluid water, the reaction of the following formula (Formula 5) occurred.

[0029]

Embedded image

Then, when it is dried, a bond of the following formula (Formula 6) is formed, and one layer of a water- and oil-repellent antifouling chemisorption monomolecular film 3 having —CF ₃ groups arranged on the surface thereof is formed via an oxygen atom. Approximately 2n when covalently bonded to the layer 2 containing almost no alkali
It was formed with a thickness of about m (FIGS. 1B and 1C).
(C) is an enlarged schematic view of the circle A part of (b).

[0031]

[Chemical 6]

In the above examples, the chlorosilane-based surfactant represented by the above formula (Formula 3) was used as the fluorosilane-based surfactant containing the fluorocarbon group and the chlorosilyl group. Surfactants that are used can be used. More specifically, the compound having a chlorosilyl group includes the following formula (Formula 7).

[0033]

[Chemical 7]

Also, a fluorosilane-based surfactant containing an alkoxy group instead of the chlorosilyl group could be used. In this case, it was necessary to add a few percent of an organic acid as a catalyst to the above-mentioned adsorbent to carry out a dealcoholization reaction, but otherwise, under the same conditions as in Example 1, a water- and oil-repellent antifouling chemical was used. A film similar to the adsorption monomolecular film 3 could be produced.
In this case, film formation was possible even if the adsorbing liquid was replaced with a water-containing solvent such as alcohol. When a water-containing solvent is used, it is convenient to use oxalic acid such as hydrochloric acid, sulfuric acid, or nitric acid. The compound having an alkoxysilyl group has the following formula (Formula 8).

[0035]

Embedded image

More specifically, the compound having a chlorosilyl group is represented by the following formula (Formula 9).

[0037]

[Chemical 9]

Although the above-mentioned substance in which fluorine was replaced by hydrogen was able to secure water repellency, it was not good in oil repellency and stain resistance. Therefore, it can be used when only water repellency is required.

Further, in addition to the chlorosilane-based surfactant and the alkoxysilane-based surfactant, as a fluorotitanate-based surfactant, for example, the following formula (Formula 10)
The compounds listed in can be used.

[0040]

[Chemical 10]

Further, as a fluorothiol type surfactant,
For example, the compound represented by the following formula (Formula 11) can be used.

[0042]

[Chemical 11]

When a fluorotitanate-based surfactant is used, adsorption occurs with a dealcoholization reaction during the preparation of the chemisorption monomolecular film, and when a fluorothiol-based surfactant is used, a dehydration reaction is performed. With this, adsorption is performed.

In the above embodiment, an example in which the fluorocarbon-based chemisorption monomolecular film is formed directly on the alkali barrier layer is shown. However, after soaking in the chemisorption solution, it is pulled out from the adsorption solution during the reaction, for example, after 5 minutes. When the solvent was evaporated in a dry atmosphere (relative humidity of about 30% or less) and further reacted with water in the air, a chemisorption polymer film in which adsorbed molecules were not oriented as shown in FIG. 1C could be formed. . If the water-repellent and oil-repellent film is too thin with a monomolecular film, the method disclosed in Japanese Patent Application Laid-Open No.
A monomolecular film may be cumulatively formed using the method disclosed in Japanese Patent No. 367721.

Next, when the wetting angle of the surface of the substrate prepared in Example 1 with water was measured, the wetting angle was 118 degrees. Therefore, the water repellency durability of this substrate was heated at 300 ° C. for accelerated evaluation. When a fluorosilane-based surfactant was directly formed on the surface of ordinary soda-lime glass in the same manner as in Example 1, the initial value was a contact angle of 115 degrees and 8 hours after the heat resistance test.
Although the glass obtained in Example 1 sandwiched the alkali barrier layer, the glass obtained in Example 1 did not deteriorate at all for 5 hours and reached 80 degrees after about 100 hours. That is, the durability was improved about 20 times as compared with the conventional one.

The dealkalization has a higher effect on the durability as the residual alkali concentration is lower, but when it is 0.1% by weight or less, the improvement effect is exhibited as compared with the conventional flat glass. It was also found that the thicker the alkali barrier layer is, the higher the durability is, but in normal use, about 1 μm can sufficiently exhibit the performance. Furthermore, when unevenness of submicron order was created on the surface of the glass substrate before the dealkalization treatment, the antifouling property was somewhat deteriorated, but the wetting angle of water was 145
It was up to 155 degrees, and the water and oil repellency and antifogging performance and durability could be improved at the same time.

(Example 2) A colored glass substrate for automobile window glass, which had been tempered in advance by air cooling, was prepared, and a SiO ₂ film containing no alkali component was formed on the substrate surface by the CVD method often used in semiconductor manufacturing. It was formed with a thickness of 1 micron. For example, using silane gas and NO ₂ gas, 400
The film was formed at a temperature of about 10 minutes. (Instead of forming such a pure SiO ₂ film, there is a problem of poor water resistance, but a PSG or BSG film containing phosphorus or boron has a higher alkali barrier effect. Also, the sol-gel method is used. It was also possible to use a method of forming a SiO ₂ coating by thermally decomposing an organic silane compound after coating or an organic silane compound). As a result, it was possible to form an alkali barrier layer containing no alkali component in the region of about 1 μm near the surface of the glass substrate.

Next, a compound represented by the following formula (Formula 12) was used as a fluorosilane-based surfactant containing a fluorocarbon group for chemisorption and a chlorosilyl group.

[0049]

[Chemical 12]

The compound represented by the formula (Formula 12) was dissolved in a non-aqueous solvent at a concentration of about 5 × 10 ^-2 Mol / L in a nitrogen atmosphere to prepare a chemisorption solution. As a non-aqueous solvent,
A 80% n-hexadecane, 12% carbon tetrachloride, 8% chloroform solution was used. After immersing the glass substrate 1 in the chemical adsorption solution at room temperature for 10 minutes, it is taken out in a dry atmosphere (relative humidity of about 10%) and dried for about 5 hours, and then taken out in ordinary air (about 60% of relative humidity). Reacted with moisture in air. Then, since the surface of the alkali barrier layer on the surface of the substrate contains a large number of hydroxyl groups, the chlorosilyl group of the chlorosilane-based surfactant and the hydroxyl groups undergo a dehydrochlorination reaction to polymerize. On the other hand, the chlorosilyl group of the unreacted chlorosilane-based surfactant remaining on the surface is polymerized by dehydrochlorination reaction with moisture in the air. Then, a polymer film containing a molecule represented by the following formula (Formula 13) partially covalently bonded to the surface of the substrate as a main component was formed with a thickness of about 5 nm through an alkali barrier layer.

[0051]

[Chemical 13]

Next, when the wetting angle of the surface of the substrate prepared in Example 2 with respect to water was measured, the wetting angle was 115 degrees. Further, the durability of this substrate was heated at 300 ° C. and accelerated evaluation was performed. When the fluorosilane-based surfactant was directly formed on the surface of the blue plate glass, the initial value was 115 ° and the deterioration was 80 ° in 5 hours after the heat resistance test. Since the alkali barrier layer of 1 micron was not contained at all, it did not deteriorate at 100 hours, and the contact angle became 80 degrees after about 500 hours. That is, the durability of the product of this example was about 100 times that of the conventional product.

[0053]

As described above, an alkali barrier layer containing no alkali or a small alkali content is formed on the surface of a glass substrate, and a surfactant is dissolved in a non-aqueous solvent to form a chemical adsorption solution. By contacting the material and chemically adsorbing the surface active agent on the surface of the alkali barrier layer to form a water- and oil-repellent antifouling coating, the durability is remarkably excellent as compared with the case where it is directly formed on a glass plate. It is effective in providing a water- and oil-repellent antifouling glass.

As the glass base material, there are window glass and mirrors used in buildings, vehicles such as automobiles, trains and airplanes, and glass used in glass containers, spectacle lenses and the like. It is needless to say that the present invention is not limited to these and can be used in any case where a highly durable chemical adsorption film is desired to be formed on glass containing alkali.

[Brief description of drawings]

FIG. 1 is a conceptual cross-sectional process diagram of a glass surface according to an embodiment of the present invention, in which (a) is a state in which an alkali barrier layer is formed and (b) is a state in which a chemical adsorption film is formed on the alkali barrier layer. , (C) are schematic views in which the circle A part of (b) is enlarged to the molecular level.

[Explanation of symbols]

1 Glass substrate 2 Layer containing no alkali or low alkali content (alkali barrier layer) 3 Fluorocarbon-based chemisorption monolayer

Claims (17)

[Claims] 1. A water- and oil-repellent antifouling glass having a chemisorption film of surfactant molecules formed by covalent bonds on the glass surface, wherein the glass surface vicinity contains no alkali metal or alkali metal. A water-repellent, oil-repellent and antifouling glass characterized by comprising an alkali barrier layer having a low content. 2. The water- and oil-repellent antifouling glass according to claim 1, wherein the surfactant molecule contains a fluorocarbon group. 3. A chemisorption film comprising surfactant molecules is S.
The water- and oil-repellent antifouling glass according to claim 1 or 2, which is covalently bonded to the surface of the substrate via an iO group. 4. A chemisorption film comprising surfactant molecules is T
The water- and oil-repellent antifouling glass according to claim 1 or 2, which is covalently bonded to the surface of the substrate via an iO group. 5. The water- and oil-repellent antifouling glass according to claim 1, wherein the alkali metal concentration of the alkali barrier layer is 0.1% by weight or less. 6. A surface active agent having a functional group that undergoes a condensation reaction with a hydrophilic group on the surface of the glass substrate is brought into contact with the glass substrate, and the hydrophilic group on the surface of the glass substrate and the functional group of the surface active agent. A method for producing a water- and oil-repellent antifouling glass in which a condensation reaction is caused with a group to chemically adsorb the surfactant, and whether an alkali metal is not included in the vicinity of the glass surface in advance before the chemical adsorption. Alternatively, a method for producing a water / oil repellent / antifouling glass, which comprises forming an alkali barrier layer having a low alkali metal content. 7. A method of forming an alkali barrier layer comprises:
7. The method according to claim 6, wherein the surface of the glass substrate is treated with a dealkalizing metal, or a layer having a composition containing no alkali metal or having a small alkali metal content is formed on the surface of the glass substrate. Method for producing water- and oil-repellent antifouling glass. 8. The method for producing a water-repellent, oil-repellent, and antifouling glass according to claim 7, wherein the dealkalizing metal treatment comprises subjecting the surface of the glass substrate to a contact treatment with a mineral acid. 9. The mineral acid is sulfuric acid, fuming sulfuric acid, hydrochloric acid, nitric acid,
The method for producing a water- and oil-repellent antifouling glass according to claim 8, which is at least one acid selected from nitrous acid, phosphoric acid, and phosphorous acid. 10. The method for producing a water-repellent, oil-repellent and antifouling glass according to claim 8, wherein the contact treatment with the mineral acid is a method of treating with mineral acid-containing water or warm water, or bringing the mineral acid into contact with a gas. . 11. The method for producing a water-repellent, oil-repellent and antifouling glass according to claim 7, wherein the method of forming the alkali barrier layer forms a coating film containing silica on the surface of the glass substrate. 12. A method of forming a coating containing silica comprises:
The method for producing a water and oil repellent antifouling glass according to claim 11, which uses a CVD (chemical vapor deposit) method or a sol-gel method. 13. The method for producing a water / oil repellent antifouling glass according to claim 6, wherein the surfactant is a fluorosilane-based surfactant having a fluorocarbon group and a chlorosilyl group or an alkoxy group. 14. The method for producing a water- and oil-repellent antifouling glass according to claim 6, wherein the surfactant is a fluorotitanium-based surfactant having a fluorocarbon group and a titanate group. 15. The method for producing a water / oil repellent and antifouling glass according to claim 13, wherein the fluorosilane-based surfactant is at least one selected from the following formulas (Formula 1) and (Formula 2). Embedded image Embedded image 16. The chemical adsorption treatment is a treatment of immersing a glass substrate in a solution in which a surfactant is dissolved in a non-aqueous solvent, or exposing the glass substrate to a gas atmosphere of the surfactant. 6. The method for producing a water- and oil-repellent antifouling glass according to 6. 17. The repellent according to claim 16, wherein the glass substrate is immersed in a solution in which a surfactant is dissolved in a non-aqueous solvent for chemical adsorption treatment, and then the unreacted surfactant is washed and removed with a non-aqueous solution. Method for producing water- and oil-repellent antifouling glass.