JP3929321B2 - Highly slidable coating and method for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a highly water-slidable coating film that exhibits extremely excellent water slidability (water droplet slidability) and can be used particularly for architectural window glass, vehicle window glass, mirrors, and other industrial glass, and a method for producing the same. .
[0002]
[Prior art]
As an attempt to improve water drop sliding properties, a composition containing a silicone-based wax, an organopolysiloxane, a surfactant and the like has been proposed. For example, Japanese Patent Publication No. 50-15473 includes an alkylpolysiloxane and an acid. JP-A-5-301742 discloses a composition containing an amino-modified silicone oil and a surfactant, and a composition that slides with a water droplet amount of about 15 μl at a 30 ° inclination is obtained. Yes. JP-A-11-181212 discloses a unit in which a group such as — (CH ₂ ) ₃ (CF ₂ ) ₇ CH ₃ is directly bonded to a silicon atom forming an organosiloxane unit, and — (CH ₂ ) ₃ SiCl. A surface treatment agent comprising a fluorine-containing silicone compound having a unit in which a group such as ₃ is directly bonded to a silicon atom forming an organosiloxane unit as an essential component and / or a partial hydrolyzate product of the compound. It is disclosed that 50 μl of water droplets slide down with an inclination of about 10 °. Japanese Patent Application Laid-Open No. 2000-144056 discloses a silicone compound having a hydrolyzable functional group at the terminal, or a silicone compound having a hydrolyzable functional group at the terminal and a fluoroalkyl group at the other end, and an acid. A functional layer obtained by dissolving water in a solvent, applying the mixed solution obtained by mixing and stirring to the substrate surface, and then drying it is chemically bonded to the substrate surface by a siloxane bond. A surface-treated substrate excellent in water droplet sliding property, which is characterized by the above, is disclosed, in which 50 μl of water droplets slide down at an inclination of about 1 °. These surface treatment agents form a water slidable layer by directly treating the water slidable component on the base material, and are based on a transparent film in which the water slidable component and the matrix component are hybridized as in the present invention. It is not something that is formed on the material.
[0003]
As a method for forming a transparent film comprising a water-sliding component and a matrix component on a substrate, JP-A-8-12375 discloses a mixture of a fluoroalkyl group-containing silane compound and dimethyl silicone and / or a derivative thereof in a solvent. A solution obtained by hydrolysis and a solution obtained by hydrolyzing an alkoxysilane compound in a solvent are mixed, and the mixture is applied to the surface of the substrate. A water-repellent article is disclosed in which methyl groups are present in a higher concentration in the outer surface layer than in the inner layer of the coating. Japanese Patent Application Laid-Open No. 2000-26758 discloses a hydroxyl group-containing vinyl polymer, an epoxy-terminated siloxane polymer, a sulfonic acid compound, an optionally blocked polyisocyanate compound, and a melamine resin as a coating composition capable of forming a water slidable film. With a coating composition capable of forming a water-slidable film containing at least one crosslinking agent component selected from the group consisting of a surfactant selected from the group consisting of a specific dialkylsulfosuccinate and an alkylene oxide silane, the falling angle at a water droplet volume of 10 μl is reduced. It is disclosed that a very excellent performance of 5 ° or less is exhibited.
[0004]
[Problems to be solved by the invention]
However, the water-repellent article described in the above-mentioned JP-A-8-12375 has a water droplet sliding property of 50 μl of water droplets that slide at an inclination of about 16 °, and is intended to remove raindrops well as an automobile window. This level is not enough. Further, the water-repellent article described in JP-A-2000-26758 has low transparency and is limited to use as a paint.
[0005]
[Means for Solving the Problems]
The present invention has been made in view of the above problems, and a dimethyl silicone composition in which a silicon atom to which an alkoxy group is bonded and a silicon atom at the end of a dimethylsiloxane chain is bonded through an oxygen or methylene group is used as a water-sliding component. As a result, it was found that the retention property of the water-sliding component in the matrix is improved, and further, if a fluoroalkylsilane having excellent durability is introduced into the matrix, a highly durable high water-sliding film can be formed. .
[0006]
That is, in the highly water-slidable coating film of the present invention, a mixture of an alkoxy-terminated dimethyl silicone represented by the general formula [1] and a fluoroalkylsilane represented by the general formula [2] is used as the water-sliding component in the silica matrix. It is characterized by being distributed.
[0007]
[Chemical 3]
[0008]
Here, X is at -OR or _{-R'Si (OR) r (CH 3} ) 3-r (R is a monovalent an alkyl group, R 'is an divalent alkylene group, r is an integer of 1 to 3) The alkoxy group or alkoxy group-containing group represented, p and q are integers of 1 to 3, and n is an integer of 2000 or less.
[0009]
[Formula 4]
[0010]
Here, s represents an integer of 0 to 11, t represents an integer of 1 to 3, and Z represents a hydrolyzable group.
The highly water-slidable coating film of the present invention is characterized in that the number of alkoxy groups in the alkoxy-terminated dimethyl silicone represented by the general formula [1] is 3 or more.
[0011]
Furthermore, the highly water-slidable coating film of the present invention is characterized in that the average degree of polymerization n of the alkoxy-terminated dimethyl silicone represented by the general formula [1] is 5 to 1000.
[0012]
Furthermore, the high water-sliding film of the present invention is characterized in that the alkoxy-terminated dimethyl silicone represented by the general formula [1] is present in an amount of 1 to 200% by weight based on silica as a matrix. And
[0013]
Furthermore, in the highly water-resistant coating film of the present invention, the fluoroalkylsilane represented by the general formula [2] is 10 to 2000 mol% with respect to the alkoxy-terminated dimethylsilicone represented by the general formula [1]. It is characterized by being present in a range.
[0014]
Further, the highly water-slidable coating film of the present invention is a component formed by bonding an alkoxy-terminated dimethyl silicone represented by the general formula [1] and a fluoroalkylsilane represented by the general formula [2] in a silica matrix. Are dispersed.
[0015]
Moreover, the manufacturing method of the highly water-slidable film of this invention is characterized by performing by the following process.
(1) preparing a silica sol as a matrix component by hydrolyzing and polycondensing alkoxysilane;
(2) A coating solution is prepared by mixing the alkoxy-terminated dimethyl silicone represented by the general formula [1], the fluoroalkylsilane represented by the general formula [2], and the silica sol prepared in the above (1). The process of
(3) A step of applying a heat treatment after applying the coating solution on the surface of the substrate.
[0016]
Furthermore, the method for producing a highly water-slidable coating film of the present invention is characterized in that the heat treatment is performed at a temperature of 600 ° C. or lower.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
In the highly water-slidable coating of the present invention, a mixture of an alkoxy-terminated dimethyl silicone represented by the general formula [1] and a fluoroalkylsilane represented by the general formula [2] is dispersed as a water-sliding component in a silica matrix. It is characterized by.
[0018]
[Chemical formula 5]
[0019]
Here, X is at -OR or _{-R'Si (OR) r (CH 3} ) 3-r (R is a monovalent an alkyl group, R 'is an divalent alkylene group, r is an integer of 1-3) The alkoxy group or alkoxy group-containing group represented, p and q are integers of 1 to 3, and n is an integer of 2000 or less.
[0020]
[Chemical 6]
[0021]
Here, s represents an integer of 0 to 11, t represents an integer of 1 to 3, and Z represents a hydrolyzable group.
For example, silica prepared as a silica sol formed by advancing hydrolysis and polycondensation reaction of alkoxysilane can be used as the matrix which is a film constituent of the high water-sliding coating. For example, a predetermined amount of alkoxysilane (for example, tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ]) and a solvent are mixed and stirred (for example, about 30 minutes) to obtain a solution A. In addition, as a solvent, lower alcohols, such as ethyl alcohol and isopropyl alcohol, and those mixed solvents are desirable, However, Ethers and ketones can also be used. On the other hand, the aqueous solution and the solvent are mixed and stirred (for example, about 30 minutes) to obtain a solution B. Next, after mixing the solution A and the solution B, the mixture is stirred for a long time (for example, about 15 hours) at room temperature to proceed hydrolysis and polycondensation reaction of alkoxysilane to obtain a silica sol. As described above, hydrolysis of alkoxysilane can be carried out by adding a small amount of water and an acid catalyst such as hydrochloric acid, nitric acid, acetic acid, etc., using alkoxysilane as a starting material, and heating the hydrolyzate at room temperature or while heating. A silica sol can be obtained by polycondensation by stirring. The method for preparing the silica sol is not limited to the above method, but the method of gradually mixing an acidic aqueous solution diluted with a solvent into a solution obtained by diluting the alkoxysilane as described above with a solvent is abrupt. This is preferable because a more homogeneous reaction can be obtained.
[0022]
Examples of the alkoxysilane include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane, methyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane. , Trialkoxysilanes such as propyltrimethoxysilane and propyltriethoxysilane, or dialkoxysilanes can be used. Among the above alkoxysilanes, trialkoxysilanes such as tetramethoxysilane, tetraethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane are preferable.
[0023]
Next, R in the alkoxy-terminated dimethyl silicone represented by the general formula [1] is a monovalent alkyl group having 1 to 6 carbon atoms, and includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and pentyl. A group, a hexyl group, a cyclohexyl group, or the like can be used. Of these, a methyl group or an ethyl group is preferable. R ′ is a divalent alkylene group having 2 to 4 carbon atoms, and an ethylene group, a propylene group, an isopropylene group, a butylene group, or the like can be used. Among them, an ethylene group is preferable.
The average degree of polymerization n of the alkoxy-terminated dimethyl silicone represented by the general formula [1] is 2000 or less, and particularly preferably in the range of 5 to 1000. When it is 2000 or more, the compatibility with silica sol is lowered, and it becomes difficult to form a transparent film.
[0024]
The alkoxy-terminated dimethylsilicone represented by the general formula [1] has at least one alkoxy group at each end that can be bonded to the silica matrix or the fluoroalkylsilane represented by the general formula [2]. Can be used. The number of alkoxy groups possessed by the alkoxy-terminated dimethyl silicone is preferably 3 or more, and if it is 2 or less, the compatibility with silica sol is lowered, and the film formability is lowered. The holding amount is reduced and the durability of the highly water-slidable coating is lowered.
[0025]
Furthermore, the alkoxy-terminated dimethyl silicone represented by the general formula [1] is preferably present in the coating solution in an amount of 1 to 200% by weight based on silica. When the content is 1% by weight or less, the amount of silicone present in the silica film is reduced, and the water slidability of the highly water slidable coating is lowered. On the other hand, if it is 200% by weight or more, the compatibility with the silica sol is lowered and it becomes difficult to form a transparent film.
[0026]
Next, examples of the fluoroalkylsilane represented by the general formula [2] include CF ₃ (CF ₂ ) ₁₁ CH ₂ CH ₂ SiCl ₃ , CF ₃ (CF ₂ ) ₁₁ CH ₂ CH ₂ SiCH ₃ Cl ₂ , CF ₃ (CF ₂ ) ₁₁ CH ₂ CH ₂ Si (CH ₃ ) ₂ Cl, CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ SiCl ₃ , CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ SiCH ₃ Cl ₂ , CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ Si (CH ₃ ) ₂ Cl, CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCl ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCH ₃ Cl ₂ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (CH ₃ ) ₂ Cl, CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ SiCl ₃ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ SiCH ₃ Cl ₂ , CF ₃ ( _{CF 2) 5 CH 2 CH 2} Si (CH 3) 2 Cl, CF 3 CH 2 CH 2 SiCl ₃ , CF ₃ CH ₂ CH ₂ SiCH ₃ Cl ₂ , CF ₃ CH ₂ CH ₂ Si (CH ₃ ) ₂ Cl, CF ₃ (CF ₂ ) ₁₁ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF _{2 11} CH ₂ CH ₂ SiCH ₃ (OCH ₃ ) ₂ , CF ₃ (CF ₂ ) ₁₁ CH ₂ CH ₂ Si (CH ₃ ) ₂ (OCH ₃ ), CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ Si (OCH) ₃ ) ₃ , CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ SiCH ₃ (OCH ₃ ) ₂ , CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ Si (CH ₃ ) ₂ (OCH ₃ ), CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCH ₃ (OCH ₃ ) ₂ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (CH ₃ ) ₂ ( _{OCH 3), CF 3 (CF} 2) 5 CH 2 CH 2 Si (OCH 3) 3, CF 3 (CF 2) 5 CH 2 CH 2 SiC _{3 (OCH 3) 2, CF} 3 (CF 2) 5 CH 2 CH 2 Si (CH 3) 2 (OCH 3), CF 3 CH 2 CH 2 Si (OCH 3) 3, CF 3 CH 2 CH 2 SiCH 3 In addition to (OCH ₃ ) ₂ , CF ₃ CH ₂ CH ₂ Si (CH ₃ ) ₂ (OCH ₃ ), etc., fluoroalkylethoxysilanes, fluoroalkylpropoxysilanes, fluoroalkylisocyanatosilanes, etc. can also be used. . Moreover, examples of the hydrolyzable group represented by Z in the general formula [2] include an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a butoxy group, or a chloro group and an isocyanate group. Things can be used.
[0027]
The fluoroalkylsilane represented by the general formula [2] is preferably present in the coating solution in an amount of 10 to 2000 mol% with respect to the alkoxy-terminated dimethylsilicone. When the amount is 10 mol% or less, the amount of fluoroalkylsilane in the silica film is small and the durability of the highly water-slidable coating film is lowered. On the other hand, if it is 2000 mol% or more, the compatibility with silica sol is lowered and it becomes difficult to form a transparent film.
[0028]
Next, the manufacturing method of the highly water-slidable coating film of the present invention will be described.
[0029]
The highly water-slidable coating film of the present invention can be produced by the following process.
(1) preparing a silica sol as a matrix component by hydrolyzing and polycondensing alkoxysilane;
(2) A coating solution is prepared by mixing the alkoxy-terminated dimethyl silicone represented by the general formula [1], the fluoroalkylsilane represented by the general formula [2], and the silica sol prepared in the above (1). The process of
(3) A step of applying a heat treatment after applying the coating solution on the surface of the substrate.
That is, a coating solution for a highly water-slidable coating is obtained by adding and mixing an alkoxy-terminated dimethyl silicone represented by the general formula [1] and a fluoroalkylsilane represented by the general formula [2] into the silica sol. Can do.
[0030]
Solvents used above include lower alcohols such as ethyl alcohol and isopropyl alcohol, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and butyl acetate, and aromatic hydrocarbon solvents such as toluene, benzene and xylene. It is preferable to use ethers such as diethyl ether and diisopropyl ether, chlorinated solvents such as chloroform and carbon tetrachloride, and mixtures thereof.
[0031]
Next, the coating solution obtained above is applied to the surface of the substrate.
Various coating methods such as hand coating, nozzle flow coating method, dipping method, spray method, reverse coating method, flexo method, printing method, flow coating method or spin coating method, and known coating means such as combinations thereof are applied. Can be adopted as appropriate. It can also be used as a simple type spray-type water repellent agent.
[0032]
Next, the coating solution applied to the substrate surface is heat-treated to fix the coating on the substrate surface.
The heat treatment may be naturally dried by air drying, or after the drying or simultaneously with the drying, the heat treatment may be performed at a temperature exceeding room temperature and 600 ° C. or less. If the temperature exceeds 600 ° C., the water-sliding component is thermally decomposed and the water-sliding property is remarkably lowered.
[0033]
The base material is not particularly limited, such as glass and plastic. For example, in the case of a glass substrate, a float glass or a roll-out that is usually used for architectural window glass or automobile window glass is used. Inorganic transparent plate glass such as glass produced by the method is preferred, and it is not particularly limited to colorless or colored, as well as its type or color tone, combination with other functional films, glass shape, etc. As a bent plate glass, of course, it can be used as various tempered glasses, strength-enhanced glass, flat plate or single plate, and can also be used as double-layer glass or laminated glass. The coating may be formed on both sides of the glass substrate.
[0034]
In addition, the base layer which consists of a metal oxide may be provided in the base-material surface where a synovial fluid is apply | coated. For example, in the case of a glass substrate, the underlying layer is preferably an oxide thin film containing a metal oxide such as silicon oxide as a main component, and the coating liquid is applied thereon to cover the highly water-slidable film. Thus, a highly lubricious glass having high durability can be obtained.
[0035]
As described above, the highly water-slidable coating of the present invention has an alkoxy group in which a silicon atom bonded to an alkoxy group capable of bonding to a silica matrix and a silicon atom at the end of a dimethylsiloxane chain are bonded via an oxygen or methylene group. Since terminal dimethyl silicone is used, the retention of the component in the silica matrix is improved, and the durability can be improved. Furthermore, durability can be improved by introducing a fluoroalkyl group having excellent durability into the coating.
[0036]
In the present invention, the water slidability is a method as described in the evaluation method of the examples described later, that is, after dropping 50 μl of pure water on the sample surface, the sample is gradually tilted, and the water droplets move. Evaluation was made by measuring the angle of inclination at the beginning. In addition, this inclination angle was made into the fall angle (degree), and the fall angle was measured in air | atmosphere (about 25 degreeC) using Kyowa Interface Science CA-A type | mold. In addition, the high lubricity of this invention means a thing with a fall angle of 10 degrees or less.
[0037]
【Example】
Examples of the present invention will be described below. The present invention is not limited to these examples. In addition, the evaluation method of a highly lubricious coating film is shown below.
[0038]
[Evaluation of high water-sliding film]
The evaluation method of the highly water-slidable coating is described below.
(1) Contact angle The angle formed by the water droplet and the sample surface when about 2 μl of pure water was placed on the sample surface having a highly water-slidable coating was measured with a contact angle meter. In addition, the CA-X type made from Kyowa Interface Science was used for the contact angle meter, and it measured in air | atmosphere (about 25 degreeC).
(2) Falling angle With the sample held horizontally, after dropping 50 μl of pure water onto the sample surface, the sample is gradually tilted, and the tilt angle at the time when the water droplet starts to move is defined as the falling angle (°). did. The sliding angle was measured in the atmosphere (about 25 ° C.) using Kyowa Interface Science CA-A type. A falling angle of 10 ° or less was regarded as acceptable.
(3) Acid resistance test 1 ml of 25% sulfuric acid aqueous solution was dropped on the surface of the sample and left at about 25 ° C. for 24 hours. Next, the surface was washed with tap water and air-dried, and then the contact angle and the falling angle were evaluated.
(4) Ceria polishing test A cotton cloth in which a suspension of 10% by weight glass abrasive Milleak E (Mitsui Mining Co., Ltd.) dispersed in tap water is impregnated and the surface of the sample is a strong 1.5 kg / cm ² . Now it was polished. The number of times of polishing (reciprocation) until 70% of the polishing range became hydrophilic was evaluated.
[0039]
Example 1
(1) fluoroalkyl silane and preparing fluoroalkyl silane mixed solution of alkoxy-terminated dimethyl silicone _{(CF 3 (CF 2) 7} CH 2 CH 2 SiCl 3, abbreviated as C8FASC) and mixed solution of alkoxy-terminated dimethyl silicone, fluoroalkyl It was obtained by mixing silane and alkoxy terminated dimethyl silicone. FIG. 1 shows the procedure for preparing a mixed solution of fluoroalkylsilane (C8FASC) and alkoxy-terminated dimethylsilicone and the mixing ratio (weight ratio) of each component.
First, an alkoxy-terminated dimethyl silicone [(CH ₃ O) ₃ SiO [Si (CH ₃ ) ₂ O] ₁₅₀ Si (OCH ₃ ) ₃ ] solution having an average degree of polymerization n of 150 diluted to 10 wt% with ethyl acetate; 70 g and ethyl acetate; 20.00 g and 0.1 mol / l nitric acid aqueous solution; 0.02 g were mixed, stirred for about 5 hours at room temperature, and then molecular sieve (manufactured by Union Showa, 4AXH-5 8 × 12); After adding 00 g, the solution A was obtained by removing the water in the reaction solution by allowing to stand at room temperature for about 20 hours. Next, solution A; 22.20 g and heptadecafluorodecyltrichlorosilane [CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCl ₃ : C8FASC, manufactured by Shin-Etsu Chemical Co., Ltd., HFTCS]; By stirring for 24 hours, a mixed solution X composed of fluoroalkylsilane and alkoxy-terminated dimethylsilicone was obtained.
[0040]
(2) Preparation of silica sol Silica sol was prepared by advancing hydrolysis and polycondensation reaction of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ : TEOS]. FIG. 2 shows the silica sol preparation procedure and the mixing ratio (weight ratio) of each component.
First, TEOS; 312.5 g and Echinen F1 (mixture of lower alcohol composed of 90 wt% ethanol and 10 wt% isopropyl alcohol); 40.0 g were mixed and stirred for about 30 minutes to obtain Solution B. Moreover, 0.1 mol / l nitric acid aqueous solution; 7.5 g, H ₂ O; 210.0 g and echinene F1; 20.0 g were mixed and stirred for about 30 minutes to obtain a solution C. Next, after mixing Solution B and Solution C, silica sol Y was obtained by stirring at room temperature for about 15 hours.
[0041]
(3) Preparation of coating solution The coating solution was obtained by mixing the mixed solution X composed of the fluoroalkylsilane and the alkoxy-terminated dimethyl silicone and the silica sol Y. FIG. 3 shows the procedure for preparing the coating solution and the mixing ratio (weight ratio) of each chemical solution.
First, mixed solution X consisting of the above fluoroalkylsilane and alkoxy-terminated dimethyl silicone; 2.5 g, methyl ethyl ketone; 7.00 g and isopropyl alcohol; 7.00 g were mixed and stirred for about 5 minutes. Next, 0.78 g of the above silica sol Y was added and stirred at room temperature for about 15 hours. Then, 26.5 g of methyl ethyl ketone and 26.5 g of isopropyl alcohol were added and stirred for 30 minutes. By the above method, the silica concentration was 0.1% by weight, the weight ratio of alkoxy-terminated dimethyl silicone to silica (hereinafter referred to as “silicone concentration”) was 37.5% by weight, and the fluoroalkylsilane to alkoxy-terminated dimethyl silicone was A coating solution having a molar ratio (hereinafter referred to as “FAS concentration”) of 250 mol% was obtained.
[0042]
(4) Cleaning of glass substrate The surface of a float glass having a size of 300 mm × 300 mm × 2 mm (plate thickness) was polished with a polishing liquid, washed with water and dried with a glass cleaning machine (produced by our company). In addition, the polishing liquid used here was a suspension obtained by mixing approximately 1% of a glass polishing agent Mille E (manufactured by Mitsui Mining Co., Ltd.) with water.
[0043]
(5) Coating of highly water-slidable coating film The coating solution prepared in (3) above was applied on the glass substrate prepared in (4) above by spin coating. First, the glass substrate, which is a glass substrate for a coating film, is placed on a spin coater, and about 25 to 30 ml of coating solution is dropped while rotating at a rotation speed of 100 rpm, and the coating is applied while maintaining the rotation speed for 30 seconds. The film was dried to obtain a transparent gel film having good film formability. Next, heat treatment was performed at 280 ° C. for 10 minutes, and the mixture was cooled to room temperature, then washed with running water (Cotton No. 300) and air-dried to obtain a glass sample with a highly lubricious coating film.
[0044]
As a result of evaluating the initial performance and durability of the glass sample with a highly water slidable film obtained by the procedure described in [Evaluation of water slidable film], the initial contact angle was 104 ° and the initial sliding angle was 8 °, which was favorable. It showed water-dropping property and maintained a high water repellency with a contact angle of 99 ° after the acid resistance test. Further, in the ceria polishing test, 35 reciprocations were required to make 70% hydrophilic, and good durability was exhibited.
The production conditions of the samples produced in Examples and Comparative Examples are shown in Table 1, and the initial performance and durability test results are shown in Table 2.
[0045]
[Table 1]
[0046]
[Table 2]
[0047]
Example 2
Alkoxy-terminated dimethyl silicone having an average degree of polymerization of 200 [(CH ₃ O) ₃ SiCH ₂ CH ₂ Si (CH ₃ ) ₂ O [Si (CH ₃ ) ₂ O] ₂₀₀ Si (CH ₃ ) ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ ] was used, and everything was the same as Example 1 except that the silicone concentration was 50 wt% and the FAS concentration was 200 mol%.
As a result, the initial contact angle was 103 °, the initial drop angle was 8 °, showing good water drop slidability, and the contact angle after the acid resistance test was 93 °, maintaining high water repellency. Further, in the ceria polishing test, 35 reciprocations were required to make 70% hydrophilic, and good durability was exhibited.
[0048]
Example 3
The procedure was the same as in Example 2 except that alkoxy-terminated dimethyl silicone [(CH ₃ O) ₃ SiO [Si (CH ₃ ) ₂ O] ₂₅₀ Si (OCH ₃ ) ₃ ] having an average polymerization degree n of 250 was used. As a result, the initial contact angle was 106 ° and the initial drop angle was 8 °, indicating good water droplet fallability, and the contact angle after the acid resistance test was 89 °, maintaining high water repellency. Further, in the ceria polishing test, 35 reciprocations were required to make 70% hydrophilic, and good durability was exhibited.
[0049]
Example 4
Alkoxy-terminated dimethyl silicone having an average polymerization degree n of 300 [(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ Si (CH ₃ ) ₂ O [Si (CH ₃ ) ₂ O] ₃₀₀ Si (CH ₃ ) ₂ CH ₂ CH ₂ Si was (OC ₂ H _{5) 3]} the same as in example 2 except for using.
As a result, the initial contact angle was 105 °, the initial drop angle was 7 °, and the water droplet tumbling property was good, and the contact angle after the acid resistance test was 88 °, maintaining high water repellency. Further, in the ceria polishing test, 35 reciprocations were required to make 70% hydrophilic, and good durability was exhibited.
[0050]
Example 5
Alkoxy-terminated dimethyl silicone having an average degree of polymerization of 100 [(CH ₃ O) ₃ SiCH ₂ CH ₂ Si (CH ₃ ) ₂ O [Si (CH ₃ ) ₂ O] ₁₀₀ Si (CH ₃ ) ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ ] was used, and everything was the same as Example 1, except that the silicone concentration was 25 wt% and the FAS concentration was 150 mol%.
As a result, the initial contact angle was 105 °, the initial drop angle was 8 °, showing good water drop slidability, and the contact angle after the acid resistance test was 97 °, maintaining high water repellency. Further, in the ceria polishing test, 35 reciprocations were required to make 70% hydrophilic, and good durability was exhibited.
[0051]
Example 6
Alkoxy-terminated dimethyl silicone having an average degree of polymerization n of 50 [(CH ₃ O) ₃ SiCH ₂ CH ₂ Si (CH ₃ ) ₂ O [Si (CH ₃ ) ₂ O] ₅₀ Si (CH ₃ ) ₂ CH ₂ CH ₂ Si All were the same as Example 5 except that (OCH ₃ ) ₃ ] was used.
As a result, the initial contact angle was 105 °, the initial drop angle was 9 °, and the water droplet tumbling property was good, and the contact angle after the acid resistance test was 93 °, maintaining high water repellency. Furthermore, in the ceria polishing test, it took 40 reciprocations to make 70% hydrophilic, and showed good durability.
[0052]
Comparative Example 1
In FIG. 1 of “Example 1 (1) Preparation of mixed solution of fluoroalkylsilane and alkoxy-terminated dimethylsilicone” above, all were the same as Example 1 except that the amount of C8FASC added was 0 g. That is, it shows that fluoroalkylsilane is not contained in the coating solution.
As a result, the initial contact angle was 105 ° and the initial drop angle was 7 °, which was a high drop drop property, but the contact angle after the acid resistance test was 76 ° and the durability was poor. Furthermore, in the ceria polishing test, 70% of the polishing was made hydrophilic by 10 reciprocations, and the durability was poor.
[0053]
Comparative Example 2
4.0 ml of the mixed solution X obtained in the above "Example 1 (1) Preparation of mixed solution of fluoroalkylsilane and alkoxy-terminated dimethylsilicone" was dropped on a glass substrate, and the entire surface of the glass with a cotton cloth (trade name: Bencott). After being fully stretched, it was air-dried for about 5 minutes. Thereafter, a heat treatment was carried out at 80 ° C. for 10 minutes in a muffle furnace, and the surplus water lubricant remaining cloudy was wiped off with iPA to obtain a transparent sample. That is, in this comparative example, a film without a silica matrix was produced.
As a result, the initial contact angle was as high as 105 °, but the initial sliding angle was as bad as 19 °, and the contact angle after the acid resistance test was also 35 ° and the durability was also poor. Further, in the ceria polishing test, 70% of the surface was hydrophilized by polishing 5 cycles or less.
[0054]
Comparative Example 3
In FIG. 1 of “Example 1 (1) Preparation of mixed solution of fluoroalkylsilane and alkoxy-terminated dimethylsilicone” above, all were the same as Example 1 except that the addition amount of alkoxy-terminated dimethylsilicone was 0 g. That is, it shows that the alkoxy-terminated dimethyl silicone is not contained in the coating solution.
As a result, the initial contact angle was 88 °, the initial sliding angle was as bad as 13 °, and the contact angle after the acid resistance test was also 70 ° as poor as durability. Further, in the ceria polishing test, 70% of the polishing was made hydrophilic by 10 reciprocations.
[0055]
Comparative Example 4
Alkoxy-terminated dimethyl silicone having an average polymerization degree n is 2500 _{[(CH 3 O) 2 (CH} 3) SiCH 2 CH 2 Si (CH3) 2 O [Si (CH 3) 2 O] 2500 Si (CH 3) 2 CH 2 All were the same as Example 1 except that CH ₂ Si (CH ₃ ) (OCH ₃ ) ₂ ] was used.
As a result, a transparent film was not obtained.
[0056]
【The invention's effect】
Since the high water-sliding film of the present invention has both high water repellency durability and excellent water slidability, for example, when used in a window glass for a vehicle, the front, side, and rear visibility during rainy weather It is easy to secure and improves the safety of driving, and further, such effects can be maintained over a long period of time.
[Brief description of the drawings]
FIG. 1 is a diagram showing a procedure for preparing a mixed solution X of a fluoroalkylsilane and an alkoxy-terminated dimethylsilicone in Example 1.
2 is a view showing a preparation procedure of silica sol Y in Example 1. FIG.
3 is a diagram showing a procedure for preparing a coating liquid in Example 1. FIG.

Claims (7)

In the silica matrix, Ri mixture of fluoroalkyl silane represented by the general formula [1] with an alkoxy-terminated dimethyl silicone and the general formula represented [2] Na are dispersed as water slip component, the general formula [1] The number of alkoxy groups of the alkoxy terminal dimethyl silicone represented by these is 3 or more, The highly lubricious coating film characterized by the above-mentioned.
Here, X is at -OR or _{-R'Si (OR) r (CH 3} ) 3-r (R is a monovalent an alkyl group, R 'is an divalent alkylene group, r is an integer of 1 to 3) The alkoxy group or alkoxy group-containing group represented, p and q are integers of 1 to 3, and n is an integer of 2000 or less.
Here, s represents an integer of 0 to 11, t represents an integer of 1 to 3, and Z represents a hydrolyzable group. High planing coat according to claim 1, wherein the average polymerization degree n of the alkoxy-terminated dimethyl silicone represented by the general formula [1] is characterized in that 5 to 1000. The high water-sliding property according to claim 1 or 2, wherein the alkoxy-terminated dimethyl silicone represented by the general formula [1] is present in an amount of 1 to 200% by weight based on silica as a matrix. Coating. The fluoroalkylsilane represented by the general formula [2] is present in a range of 10 to 2000 mol% with respect to the alkoxy-terminated dimethylsilicone represented by the general formula [1]. Item 4. The highly water-slidable coating film according to any one of Items 1 to 3 . A component formed by bonding an alkoxy-terminated dimethyl silicone represented by the general formula [1] and a fluoroalkylsilane represented by the general formula [2] is dispersed in a silica matrix. Item 5. The highly water-slidable coating film according to any one of Items 1 to 4 . The method for producing a highly water-slidable coating film according to any one of claims 1 to 5, which is performed by the following steps.
(1) preparing a silica sol as a matrix component by hydrolyzing and polycondensing alkoxysilane;
(2) A coating solution is prepared by mixing the alkoxy-terminated dimethyl silicone represented by the general formula [1], the fluoroalkylsilane represented by the general formula [2], and the silica sol prepared in the above (1). The process of
(3) A step of applying a heat treatment after applying the coating solution on the surface of the substrate. The method for producing a highly water-slidable coating film according to claim 6 , wherein the heat treatment is performed at a temperature of 600 ° C. or less.