KR100492396B1 - A substrate having a treatment surface and surface treating method for a substrate - Google Patents

Abstract

The water repellent film is firmly bonded to the surface through the base film, and the water repellent and / or oil repellent film is formed using the base treatment liquid to obtain a substrate having a low critical tilt angle, excellent durability, and high density. The base treatment liquid is obtained by dissolving and reacting a substance having a chlorosilyl group in a molecule in an alcohol solvent, thereby obtaining a surface roughness Ra of 0.5 nm or less, thereby achieving high durability and low critical tilt angle.

Description

A substrate having a treatment surface and surface treating method for a substrate

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a substrate having a surface-treated glass, ceramic, plastic, or metal, that is, a substrate having a water-repellent coating layer or coating formed on a base coating layer or coating and a surface treatment method thereof. will be.

Conventionally, for example, a substrate made of glass or the like and having a water repellent coating layer or a film formed thereon is, for example, Japanese Patent Application Laid-open No. Hei 4-20781, Japanese Patent Application Laid-open No. Hei 5-86353, and Japanese Laid-Open Patent Publication. Japanese Patent Laid-Open No. Hei 5-161844, Japanese Laid-Open Patent Publication No. Hei 2-311332 and Japanese Patent No. 2,525,536 are already known.

Japanese Patent Application Laid-open No. Hei 4-20781 discloses a water repellent oil repellent material comprising a silane compound or a coating layer made of a synthetic resin that does not contain a polyfluoro group, formed on a surface of a substrate, and a silane compound containing a polyfluoro group thereon. Disclosed is a substrate on which a multilayer coating layer or coating is formed.

In JP-A-5-86353, a thin film of siloxane groups is formed on a surface of glass, ceramic, plastic, or metal by using a compound containing a chlorosilyl group such as SiCl ₄ in a molecule thereof. A method of forming a chemisorbed monomolecular cumulative layer or film (water repellent coating or coating layer) thereon is disclosed.

Japanese Unexamined Patent Application Publication No. Hei 5-161844 discloses that a monomolecular film of siloxane groups or an adsorption film of polysiloxane is formed on the surface of a substrate in advance, and then a chemical adsorption step is performed in an atmosphere containing a surfactant of chlorosilane groups. A method of forming a chemisorption monomolecular film (water repellent coating or coating layer) on a substrate surface is disclosed.

Japanese Unexamined Patent Application Publication No. Hei 2-311332 discloses a water repellent glass obtained by silylating the surface of a glass substrate (formed from a metal oxide such as SiO ₂ ) by a silyl compound such as fluorinated alkylsilane.

In addition, Japanese Patent No. 2,525,536 discloses an underlying film or coating layer made of silica on a glass substrate before treating the substrate surface with a fluorine compound in the same manner as disclosed in Japanese Patent Laid-Open No. 2-311332. A technique of forming and containing an olefin telomer in a fluorine compound to improve weather resistance of the water repellent membrane is disclosed.

In the substrate obtained by the method disclosed in Japanese Patent Application Laid-open No. Hei 4-20781, since the density of the base coating layer is low, the thickness of the base coating layer should be 100 nm or more and the firing temperature should be 400 ° C or more. .

In the method disclosed in JP-A-5-86353, the adsorption treatment agent is unstable by reacting with water in the air, so it is necessary to keep the humidity of the atmosphere low, and it is difficult to manage the environmental conditions. In addition, the process takes 2-3 hours, and there is a problem that the non-aqueous solvent is expensive.

In order to carry out the method disclosed in Japanese Patent Laid-Open No. 5-161844, the apparatus for controlling the atmosphere must be large-scale, and it takes time to form a complete adsorption membrane.

In the substrate obtained by the method disclosed in Japanese Unexamined Patent Publication No. 2-311332, in order to obtain a high density metal oxide layer when forming a metal oxide film through a sol-gel method, for example, 500 Since firing at 占 폚 is necessary, a large-scale apparatus is required for firing the substrate at a high temperature, so that the manufacturing cost increases. Moreover, when this method is implemented, the roughness of the obtained metal oxide film is comparatively high, and the water droplet which exists in the surface of water-repellent glass becomes difficult to roll freely in the surface.

In addition, in the substrate obtained by the method disclosed in Japanese Patent No. 2,525,536, the weather resistance is excellent, but the durability of the water repellent film in the friction test is obtained through double-checking, and the silica base Since the roughness of the surface of an application layer or a coating film is comparatively high, the water droplet which exists in the surface of water-repellent glass is difficult to roll freely in the surface.

In order to solve the above disadvantages of the prior arts, according to the present invention, a substance having a chlorosilyl group in a molecule on a surface of a substrate made of glass, ceramic, plastic or metal is dissolved and reacted in an alcohol solvent. The base treatment liquid obtained by drying is dried to form an undercoat, and a water / oil repellent surface layer is formed on the undercoat, and the surface roughness Ra of the surface layer is 0.5 nm or less. A surface treated substrate is provided.

In addition, the surface roughness Ra of the surface layer is preferably as small as possible. However, for example, the surface roughness Ra of the fire polished surface of the float glass (ie, the top surface of the float glass floating on the molten tin) is about 0.2 nm, and through precision polishing Roughness Ra of the obtained glass surface is about 0.1 nm. Thus, the virtually lowest limit of the surface roughness Ra of the glass surface that can be obtained is about 0.1 to 0.2 nm.

As described above, the base film or the coating layer formed of the base treatment liquid obtained by dissolving and reacting a substance having a chlorosilyl group in the molecule in an alcohol solvent has a high flatness, and thus the surface layer formed on the base coating or the coating layer. High flatness (Ra reflects the flatness of the film 0.5 nm) resulting in good water repellency, ie high contact angle and low critical tilt angle.

Here, it is possible to eliminate the appearance defects by keeping the surface of the substrate clean when forming the undercoat or coating layer on the substrate, and also increase the adhesive strength between the substrate surface and the undercoat by activating the surface of the substrate. It may be. For example, even if the glass substrate contains an oxide, the surface is 0.5 nm with an abrasive. Ra It is possible to form the active surface by polishing in the 3.0 nm range.

However, when the roughness Ra of the substrate surface exceeds 3.0 nm, it is difficult to make the roughness Ra of the surface layer (water repellent layer) 0.5 nm or less even if the substrate treatment is performed. Therefore, the roughness Ra of the substrate surface is preferably 3.0 nm or less. In addition, when the substrate is made of a glass plate, the roughness Ra is 0.5 nm. Ra The transparency of the substrate can be maintained when in the 3.0 nm range.

When the surface of the substrate lacks hydrophilic groups, the surface of the substrate is treated with an oxygen-containing plasma or a corona discharge atmosphere or irradiated with ultraviolet light having a wavelength of about 200 to 300 nm on the surface of the substrate in an oxygen-containing atmosphere. The surface treatment is preferably performed after the surface is hydrophilized.

In addition, according to the present invention, it is appropriate to limit the concentration of the substance having the chlorosilyl group in the molecule in the underlying treatment liquid to 0.01 wt% or more and 3.0 wt% or less.

Chloro silyl group Examples of a material having in the molecule, SiCl _4, SiHCl _3, SiH ₂ Cl _2, etc. may be mentioned, and may select one or a plurality of materials from among these. In particular, since it contains the most Cl groups, the SiCl ₄ is preferred. The chlorosilyl group is very reactive and forms a fine and dense underlying film by self-condensation reaction or by reaction with the substrate surface. However, it may contain a substance in which a part of the hydrogen group is substituted with a methyl group or an ethyl group.

Moreover, as an alcohol solvent, methanol, ethanol, 1-propanol, and 2-propanol are preferable, for example. The substance which has a chlorosilyl group in a molecule | numerator, and an alcohol solvent react so that an alkoxide may be formed by removing hydrogen chloride, as shown by following formula (1).

(-Si-Cl) + (ROH) (-Si-OR) + (HCl) ... (1)

In addition, the substance which has a chlorosilyl group in a molecule | numerator, and an alcohol solvent may react as shown by following formula (2).

(-Si-Cl) + (ROH) (-Si-OH) + (HCl) ... (2)

In an alcohol solvent, a part of (-Si-OR) reacts with the acid catalyst produced as represented by Formula (1) as shown by following formula (3), and produces (-Si-OH).

(-Si-OR) + (H ₂ O) (-Si-OH) + (ROH) ... (3)

In addition, (-Si-OH) generated as represented by the above formulas (2) and (3) reacts as shown by the following formula (4) to form a siloxane bond.

(-Si-Cl) + (-Si-O) (-Si-O-Si) + (HCl) ... (4)

By the siloxane bond, it is considered that the bond between the substrate and the underlying film or between the underlying film and the surface layer (water repellent mix) is made firm. In other words, when a compound containing a siloxane bond is used only with the underlying treatment liquid as disclosed in the prior art, even if the siloxane bond is present in the underlying film, the siloxane connecting between the substrate and the underlying film or between the underlying film and the water repellent film Bonding doesn't affect that much.

According to the present invention, by treating a substance having a chlorosilyl group in a molecule and an alcohol solvent after mixing with an undertreatment solution obtained by reacting within 30 minutes, an undercoat having excellent flatness can be formed, and a part of the chlorosilyl group is formed of siloxane. Because of the contribution to the bond, good bond between the substrate and the water repellent film can be obtained by this siloxane bond.

Here, the concentration of a substance having a chlorosilyl group in the molecule contained in the underlying treatment liquid depends on the coating method, but is preferably 0.01 wt% or more and 3.0 wt% or less. If the concentration is lower than this, there is no addition effect of the substance. If the concentration is higher than this, the substance addition effect is not improved. In particular, in the case of applying by using a curtain flow coating method, for example, it is preferable that the concentration is 0.03 wt% or more and 1.0 wt% or less by judging by the appearance during application.

The method of applying the base treatment liquid is not particularly limited. However, alternatively, dip coating, curtain flow coating, spin coating, bar coating, roll coating, hand coating, brush painting, spray coating Law and the like.

Moreover, as surface treatment performed in this invention, water-repellent treatment and oil-repellent treatment are mentioned, for example. The agent for water and oil repellent treatment is not particularly limited, but a treatment method using a water repellent or a oil repellent containing a silane compound, a siloxane compound or a silicone compound is preferable.

As an example of a silane compound,

CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ ,

CF ₃ (CF ₂ ) ₆ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ ,

CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ SiCl ₃ ,

And a water repellent containing CF ₃ (CF ₂ ) ₆ (CH ₂ ) ₂ SiCl ₃ .

These water repellents can be used by hydrolysis using a catalyst such as an acid or a base if necessary. In addition, medicaments containing siloxane compounds that can be obtained through hydrolysis or condensation of the silane compounds can also be used.

As the silicone compound, linear or linear polydimethylsiloxane, or silanol modification, alkoxide modification, hydrogen modification, halogen modification, or the like can be used.

Although it does not specifically limit as a water-repellent or oil-repellent treatment method, The hand coating method, the brush painting method, etc. are mentioned similarly to the case of a base treatment.

Moreover, as surface treatment which concerns on this invention, a hydrophilic treatment or an antifogging treatment is mentioned besides water-repellent or oil-repellent treatment.

Hereinafter, embodiments of the present invention will be described in detail.

(Example 1)

To 100 g of ethanol (manufactured by Nakaraitekusu), 0.01 g of chlorosilane (SiCl ₄ ) (manufactured by Shinnetsu Silicon) was added and mixed to obtain an underlying treatment solution. The obtained base treatment liquid was applied on a polished and cleaned glass substrate (300 x 300 mm) at 40% humidity and room temperature, and then dried for about 1 minute to obtain a base film.

Then, 1.3 g of CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ (heptadecafluorodecyltrimethoxisilane) (manufactured by Toshiba Silicon) was dissolved in 40.6 g of ethanol and mixed for 1 hour, followed by 0.808 g of ion-exchanged water. And 1.0 g of 0.1 N hydrochloric acid were added, and the mixture was further mixed for 1 hour to obtain a water repellent agent A.

Thereafter, 3 ml of a water repellent agent A was soaked in a cotton cloth and applied to a glass substrate having a film formed by a base treatment, and then the excessively applied water repellent agent was wiped with a new cotton cloth soaked with ethanol, and the water repellent glass substrate Got.

The contact angle with a 2 mg droplet was measured at a static contact angle using a contact goniometer (CA-DT, Kyowa Kaimen Kagaku).

As a weather resistance test, the ultraviolet light intensity was 76 ± 2 mW / cm ² using a Super UV tester (W-13, manufactured by Iwasaki Denki Co., Ltd.) and irradiated for 20 hours in a dark cycle of 4 hours. Ultraviolet light was irradiated for 400 hours under conditions of showering the substrate with ion-exchanged water for 30 seconds every 1 hour.

In addition, as a friction test, a water-rubber eraser (Lion, No. 502) was rubbed 100 times with water-repellent glass with a load of 50 g in an area of 15 x 7 mm.

In addition, the critical inclination angle was measured as a measure of water repellency. In order to measure the rolling performance of water droplets on the surface of the water-repellent glass (contact angle = 100 to 110 °), a water droplet having a diameter of 5 mm (the shape is close to a hemispherical shape when the contact angle is 100 to 110 °) is horizontally. After dropping on the surface of the water-repellent glass which was arrange | positioned, the water-repellent glass was inclined gradually, and the inclination angle (critical inclination angle) when the water droplet which adhered to the surface of the water-repellent glass started to roll was recorded. The smaller the critical inclination angle, the better the dynamic water repellency. For example, this applies to raindrops that must be easily removed so that they fall on the windshield of the car while driving and do not interfere with the driver's vision.

However, as the smoothness of the obtained water-repellent glass, the surface roughness Ra is calculated by measuring the surface contour by an atomic force microscope (SPI3700, manufactured by Seiko Electronic) in a cyclic contact mode.

As shown in Table 1, the initial contact angle was 108 °, the initial critical tilt angle was 13 °, and the contact angle after the weather resistance test of 400 hours was 88 °, and the contact angle after the friction test, which is a measure of durability, was 84 °. One)

delete

A water-repellent glass substrate was obtained in the same manner as in Example 1 except that 0.005 g (0.005 wt%) of chlorosilane was added in the preparation of the substrate treatment liquid.

As shown in Table 1, although the initial contact angle showed 107 degrees, the initial inclination angle was large at 18 degrees, the contact angle after the weather resistance test was lowered to 71 degrees, and the durability was lowered.

(Examples 2 to 4 and Comparative Example 2)

Example 1 except that 0.5 g, 1.0 g, 3.0 g, and 5.0 g (concentrations of 0.5 wt%, 1.0 wt%, 3.0 wt% and 5.0 wt%) were added to the preparation of the treatment solution. In the same manner as in the water-repellent glass substrate was obtained. That is, in Example 2, 0.5 g of chlorosilane (concentration 0.5 wt%) was added, and in Example 3, 1.0 g of chlorosilane (concentration 1.0 wt%). ) Was added, and in Example 4, 3.0 g of chlorosilane (3.0 wt% in concentration) was added, and in Comparative Example 2, 5.0 g of chlorosilane (5.0 wt% in concentration) was added.

When the concentration of chlorosilane is high, the thickness of the underlying film becomes thick, and as a result, the interference of light gradually becomes stronger. If the concentration of chlorosilanes exceeds 5 wt%, a marked increase in color reflection may be noticeable. If the concentration of chlorosilane is further increased to increase the thickness of the underlying film, a firing step is further required.

(Example 5)

In a 1 liter glass reactor equipped with a thermometer, a mixer and a cooler, 10.0 g of CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ (manufactured by Toshiba Silicon) and a hydrolyzable compound represented by the following formula (1) 10.0 g of group-containing polydimethylsiloxane were co-hydrolyzed at 80 ° C. for 5 hours with 360 g of t-butanol and 1.94 g of 0.1 N hydrochloric acid, and 160 wt% of n-hexane was added to room temperature. Mix for 10 hours.

[Formula 1]

Further, 10.0 g of organopolysiloxane and 5.0 g of metasulfonic acid represented by the following formula (2) were added to the mixture, followed by mixing for 10 minutes to obtain a water repellent agent B.

[Formula 2]

In the same manner as in Example 1, a water repellent agent was applied onto a substrate treated glass substrate prepared with a SiCl ₄ concentration of 0.5 wt% to obtain a water repellent glass substrate.

Also in this water-repellent glass substrate, as shown in Table 1, excellent results in initial contact angle and durability (that is, weather resistance test and friction test) can be obtained.

(Comparative Examples 3 and 4)

After the substrate treatment using tetrachlorotin or tetrachlorozirconium instead of chlorosilane as the substrate treatment agent, a water-repellent glass substrate was produced using the above-described water repellent agent B.

Although the initial contact angle represented 106 °, the initial critical inclination angles were large as 18 ° and 19 °, and the contact angles after the weathering test were reduced to 65 ° and 64 °, respectively.

(Comparative Example 5)

A water-repellent glass substrate was prepared in the same manner as in Example 1 except that chloroform was used instead of ethanol as a solvent for the substrate treatment liquid.

Table 1 shows a large initial contact angle of 107 °, but the initial critical inclination angle was large at 20 °, the contact angle after the weathering test was reduced to 63 °, and the contact angle after the friction test was reduced to 67 °.

(Comparative Example 6)

Comparative Example 6 was performed with respect to double inspection Example 6 disclosed in Japanese Patent No. 2,525,536.

That is, a water repellent glass substrate was obtained in the same manner as in Example 1 except that a perfluorocarbon solution (FC-77, manufactured by 3M) was used instead of ethanol as the solvent for the substrate treatment liquid.

As a result, the surface roughness shows a high value of 7.0 nm and the initial critical tilt angle of 25 degrees. In addition, although the initial contact angle appeared to be 107 °, the contact angle after the friction test was reduced to 65 °.

(Comparative Example 7)

Comparative Example 7 was performed with respect to the double inspection Example 3 disclosed in Japanese Unexamined Patent Publication No. 2-311332 described above in the prior art.

That is, 31 g of tetraethylsilicate (manufactured by Colcoat) was dissolved and mixed in 380 g of ethanol at room temperature at 20 ° C for 24 hours while 6.5 g of water and 1.6 g of 1N hydrochloric acid were added and mixed to prepare a base treatment solution.

This base treatment liquid was applied by a flow coating method in the same manner as in Example 1 and dried for about 1 minute. After the substrate treatment, the substrate was heated at a temperature of 500 ° C. for 1 hour in a heating step to form a silicon oxide layer. Thereafter, a water-repellent glass substrate was obtained using the above-mentioned water repellent agent A in the same manner as in Example 1.

Surface roughness (Ra) was high at 0.6 nm, and the initial critical tilt angle was also high at 22 °. The contact angle was 107 °, but dropped to 67 ° after the friction test.

(Comparative Example 8)

A water repellent glass substrate was obtained in the same manner as in Comparative Example 7 except that the heating step of the base film was not performed.

Surface roughness (Ra) was high at 0.7 nm, and the initial critical tilt angle was also high at 23 °. The contact angle was 108 °, but dropped to 45 ° after the friction test.

Table 1 shows the results of the above examples and comparative examples.

Table 1

Raw material (concentration wt%) Water repellent Exterior Surface Roughness Ra (nm) Initial contact angle (°) Initial critical slope angle (°) Contact angle (°) after weathering test (400H) Contact angle after friction test (100 times) (°) Example 1 Comparative Example 1 SiCl ₄ /0.01 SiCl ₄ /0.005 A A OK OK 0.4 0.9 108 107 13 18 82 71 84 65 Example 2 Example 3 Example 4 Comparative Example 2 _{SiCl 4 /0.5 SiCl 4 /1.0 SiCl 4} /3.0 SiCl 4 /5.0 A A A A OK OK OK Reflective color outstanding 0.2 0.3 0.2 0.3 107 108 109 107 12 12 13 12 86 87 86 87 82 87 87 84 Example 5 Comparative Example 3 Comparative Example 4 SiCl ₄ /0.5 SiCl ₄ /1.0 SiCl ₄ /1.0 B B B OK OK OK 0.2 0.7 0.6 108 106 106 12 18 19 88 65 64 86 80 83 Comparative Example 5 Comparative Example 6 SiCl ₄ /1.0*1 SiCl ₄ /1.0*2 A A OK OK 0.8 7.0 107 107 20 25 63 60 67 65 Comparative Example 7 Comparative Example 8 TEOS / 0.4 * 3 TEOS / 0.4 * 3 A A OK OK 0.7 0.7 107 108 22 23 54 50 67 45

* 1 solvent: chloroform

* 2 solvent: perfluorocarbon * 3 solvent: see second paragraph of Comparative Example 7

Ra was measured according to the standard of JIS B 0601-1982.

As described above, according to the substrate and the treatment method of the present invention, since a highly reactive compound having a chlorosilyl group in a molecule is used as the substrate treatment liquid, it is not necessary to perform baking at a high temperature after the substrate coating is formed. As a result, no large-scale equipment is needed, and production costs can be reduced.

In addition, since it is sufficient to apply the substrate treatment agent without using the liquid phase adsorption and vapor phase adsorption methods, the treatment time can be shortened, and the substrate treatment liquid can be uniformly and thinly applied by using an inexpensive alcohol solvent.

The surface treated substrate according to the invention contributes to the water and oil repellent windshield of the motor vehicle.

Claims (7)

On the surface of a substrate made of glass, ceramic, plastic, or metal, a base treatment solution obtained by dissolving and reacting a substance having a chlorosilyl group in a molecule in an alcohol solvent is dried to form an undercoat. A water-repellent or oil-repellent surface layer in which the surface roughness Ra of the surface layer is 0.5 nm or less. The surface-treated substrate according to claim 1, wherein the concentration of the substance having the chlorosilyl group in the molecule in the substrate treatment liquid is 0.01 wt% or more and 3.0 wt% or less. The surface-treated substrate according to claim 1, wherein the concentration of the substance having the chlorosilyl group in the molecule in the substrate treatment liquid is 0.03 wt% or more and 1.0 wt% or less. The material according to any one of claims 1 to 3, wherein the substance having a chlorosilyl group contained in the base treatment liquid in a molecule contains at least one of SiCl ₄ , SiHCl ₃ and SiH ₂ Cl ₂ . Surface Treated Substrate. The surface-treated substrate according to any one of claims 1 to 3, wherein the surface of the substrate on which the base film is formed is polished and washed with a surface roughness Ra of 0.5 nm to 3.0 nm. A method of treating a surface of a substrate, comprising: applying a substrate treatment liquid obtained by dissolving and reacting a substance having a chlorosilyl group in a molecule in an alcohol solvent on a surface of a substrate made of glass, ceramic, plastic, or metal; After the applied base treatment liquid is dried; A surface treatment method for a substrate, characterized by performing a surface treatment for forming a water / oil repellent surface without firing. The surface-treated substrate according to claim 4, wherein the surface of the substrate on which the base film is formed is polished and washed with a surface roughness Ra of 0.5 nm to 3.0 nm.