Surface Modifiers

Abstract

A surface modifier containing, as an active ingredient, a condensation reaction product of a perfluoropolyether group-containing silane compound and a silicate oligomer at a mass ratio of 40:60 to 10:90, wherein the perfluoropolyether group-containing silane compound is a compound represented by general formula (I): CF3(CF2)mO(C3F6O)n(C2F4O)o(CF2O)p(C2F4)q(CF2)rCONX(CH2)sSi(OR)3 (in the formula, m is an integer of 0-2, preferably 2; n, o, and p each are an integer of 0-50, preferably 5-20; q and r each are an integer of 0-2; s is an integer of 0-10, preferably 1-3; X is a hydrogen atom or (CH2)sSi(OR)3; and R is a C1-3 alkyl group). This surface modifier has excellent water and oil repellency, antifouling properties, weather resistance, and durability (wear resistance), as well as good coating film transparency and liquid storage stability.

Description

[Technical Field]

[0001] The present invention relates to a surface modifier, and more specifically to a surface modifier that is capable of forming a coating film that has excellent water and oil repellency, as well as stain resistance, weather resistance, durability (abrasion resistance), coating film transparency, and liquid storage stability. [Background technology]

[0002] BACKGROUND ART Surface modifiers using fluorine-containing compounds are used to impart properties such as slipperiness, water repellency, and stain resistance to the surfaces of glass substrates such as touch panels, eyeglass lenses, and windshields. In practice, perfluoroalkyl group-containing silane coupling agents and perfluoropolyether group-containing silane coupling agents are mainly used.

[0003] Silane coupling agents containing perfluoroalkyl groups are rigid monomolecular chains that tend to crystallize easily, and although they produce coatings with excellent weather resistance, they have issues with stain resistance and abrasion resistance. Furthermore, while perfluoroalkyl groups with eight or more carbon atoms tend to exhibit excellent performance, it has been reported that telomer compounds containing perfluoroalkyl groups with such carbon atoms are biodegraded in the environment and converted into compounds with relatively high bioaccumulation and environmental concentration. This raises concerns about exposure during the treatment process, release into the environment from waste, treated substrates, etc., and diffusion into the environment.

[0004] Furthermore, the production process of telomer compounds with perfluoroalkyl groups containing 8 or more carbon atoms inevitably results in the generation or contamination of highly bioaccumulative perfluorooctanoic acids. This has led manufacturers of such telomer compounds to withdraw from production or to switch to compounds with perfluoroalkyl groups containing 6 or fewer carbon atoms.

[0005] On the other hand, compounds with perfluoroalkyl groups containing six or fewer carbon atoms have significantly lower crystallinity, melting point, glass transition temperature (Tg), etc. than compounds with eight or more carbon atoms, and are significantly affected by the usage environment, so they do not achieve the required sufficient performance and their durability is also affected.

[0006] Here, perfluoropolyether group-containing silane coupling agents are compounds in which an ether bond has been introduced into a perfluoroalkyl chain, and because they are amorphous, oily, flexible molecular chains, they have water and oil repellency, chemical resistance, slipperiness, stain resistance, mold releasability, etc., and these properties have been utilized industrially to find a wide range of applications in oil repellents for equipment, mold release agents, cosmetics, protective films, etc.

[0007] When the fluorine-containing silane compound disclosed in Patent Document 1 is dissolved in a fluorine-based solvent and the prepared coating liquid is applied to a glass surface, the surface is covered with a coating film of a perfluoropolyether group-containing silane coupling agent, which is said to lower the surface free energy and impart water and oil repellency, antifouling properties, releasability, etc. However, although this coating film has good initial performance after application, its durability (weather resistance, abrasion resistance, releasability) may be insufficient, and further improvement in durability has been desired.

[0008] Patent Document 2 proposes improving fingerprint adhesion and antifouling properties by adding a fluorine-containing alkoxysilane compound to silica sol and using a prepared coating liquid. However, the treating agent disclosed therein has problems such as the formation of a compound that is insoluble in the solvent after reaction and precipitates, and also the surface taking on a structural color after application to a substrate such as glass, causing problems with the appearance of the coating film, and the storage stability of the solution being poor. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] WO 2015 / 146861 A1 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-51976 Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a surface modifier that is excellent in water and oil repellency, antifouling properties, weather resistance, and durability (abrasion resistance), as well as in coating film transparency and liquid storage stability. [Means for solving the problem]

[0011] The object of the present invention is to provide a compound of the general formula CF3(CF2) m O(C3F6O) n (C2F4O) o (CF2O) p (C2F4) q (CF2) r CONX(CH2) s Si(OR)3〔I〕 (wherein m is an integer of 0 to 2, preferably 2; n, o, and p are each an integer of 0 to 50, preferably 5 to 20; q and r are each an integer of 0 to 2; s is an integer of 0 to 10, preferably 1 to 3; and X is a hydrogen atom or (CH2) s a perfluoropolyether group-containing silane compound represented by the formula (Si(OR)3, where R is an alkyl group having 1 to 3 carbon atoms); , methyl silicate, ethyl silicate or a mixture thereof having a weight average molecular weight Mw of 500 to 1500 This is achieved by using a surface modifier containing, as an active ingredient, a condensation reaction product with silicate oligomer in a mass ratio of 40:60 to 10:90. [Effects of the Invention]

[0012] The surface modifier of the present invention uses a perfluoropolyether group-containing silane compound with a flexible structure that is less likely to accumulate in living organisms and the environment. By combining this with a silicate oligomer with multiple adhesive functional groups, the surface modifier exhibits excellent effects, such as improved adhesion to the substrate, improved dynamic water and oil repellency (low sliding angle), weather resistance, and abrasion resistance, in addition to water and oil repellency. These effects are believed to be due to the dense polysiloxane structure formed between the perfluoropolyether chains formed on the surface layer and the substrate acting as a strong binder, and the adjusted density of the perfluoropolyether chains, which allows for high mobility. By diluting this surface modifier to an appropriate concentration, coating film transparency and liquid storage stability can be maintained. DETAILED DESCRIPTION OF THE INVENTION

[0013] The perfluoropolyether group-containing silane compound is represented by the general formula: CF3(CF2) m O(C3F6O) n (C2F4O) o (CF2O) p (C2F4) q (CF2) r CONX(CH2) s Si(OR)3〔I〕 (wherein m is an integer of 0 to 2, preferably 2; n, o, and p are each an integer of 0 to 50, preferably 5 to 20; q and r are each an integer of 0 to 2; s is an integer of 0 to 10, preferably 1 to 3; and X is a hydrogen atom or (CH2) s Si(OR)3, where R is an alkyl group having 1 to 3 carbon atoms.) is used.

[0014] Such compounds include, for example, C3F7O[CF(CF3)CF2O] n CF(CF3)CONH(CH2)3Si(OCH3)3 C3F7O[CF(CF3)CF2O] n CF(CF3)CON[(CH2)3Si(OCH3)3]2 C3F7O[CF(CF3)CF2O] n (CF2O) p CONH(CH2)3Si(OCH3)3 C3F7O[CF(CF3)CF2O] n (CF2O) p CON[(CH2)3Si(OCH2CH2CH3)3]2 C3F7O(CF2CF2CF2O) n CF2CF2CONH(CH2)3Si(OCH3)3 C3F7O(CF2CF2CF2O) n CF2CF2CONH(CH2)3Si(OCH2CH3)3 C2F5O(CF2CF2O) o (CF2O) p CONH(CH2)3Si(OCH3)3 CF3O(CF2CF2O) o CF2CONH(CH2)3Si(OCH3)3 and the like, and preferably C3F7O[CF(CF3)CF2O] n CF(CF3)CONH(CH2)3Si(OCH3)3 C3F7O[CF(CF3)CF2O] n CF(CF3)CON[(CH2)3Si(OCH3)3]2 is used.

[0015] As silicate oligomers, methyl silicate, ethyl silicate or A mixture of these is used that has a weight-average molecular weight Mw of 500 to 1500. If a mixture with a weight-average molecular weight Mw greater than this is used, the mixture will thicken and gel, preventing the storage stability and inherent water and oil repellency from being fully exhibited, while if a mixture with a smaller weight-average molecular weight Mw is used, the coating film will be prone to unevenness and will not fully exhibit durability.

[0016] As such silicate oligomers, commercially available products such as MKC Silicate MS51 and MS56, which are methyl silicates manufactured by Mitsubishi Chemical, Ethyl Silicate 40, which is an ethyl silicate manufactured by Colcoat Co., Ltd., and EMS-485, which is a mixture of methyl silicate and ethyl silicate manufactured by Colcoat Co., Ltd., can be used as they are.

[0017] The perfluoropolyether group-containing silane compound and silicate oligomer are used in a mass ratio of 40:60 to 10:90, preferably 40:60 to 20:80. If the perfluoropolyether group-containing silane compound is used in a ratio greater than this relative to the silicate oligomer, the coating film appearance, film-forming properties, antifouling properties, weather resistance, durability (abrasion resistance), etc. will be inferior, while if it is used in a smaller ratio, not only will the water and oil repellency and antifouling properties be reduced, but gelation will be more likely, making the liquid storage stability insufficient.

[0018] The perfluoropolyether group-containing silane compound and silicate oligomer are dissolved together with a catalyst in a solvent in which they are soluble, preferably a mixed solvent of a fluorine-based organic solvent and a water-soluble organic solvent, and hydrolysis and condensation reactions are carried out to prepare a surface modifier stock solution.

[0019] Examples of fluorine-based organic solvents include fluorinated alkanes and fluoroalkyl ethers, such as 1,4-bis(trifluoromethyl)benzene, ethyl nonafluorobutyl ether, ethyl nonafluoroisobutyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, and 1,1,1,2,3,4,4,5,5,5-decafluoropentane, and preferably those having 4 to 8 carbon atoms. Commercially available products such as the Novec series from 3M and AE-3000 from AGC can be used as they are.

[0020] Examples of the water-soluble organic solvent include ketones such as acetone and methyl ethyl ketone, and alcohols such as methanol, ethanol, and isopropyl alcohol. The water-soluble organic solvent is added for the purpose of obtaining solubility of the silicate oligomer and water derived from the catalyst.

[0021] The solvent affects the solubility of the perfluoropolyether group-containing silane compound, silicate oligomer, and catalyst, the reactivity of the hydrolyzable group, the volatility of the coating liquid, the film-forming properties of the coating film, and ultimately the transparency of the coating film, so a mixed solvent of one or more fluorine-based solvents and one or more water-soluble organic solvents is preferably used.

[0022] Examples of catalysts include organic titanium compounds such as tetra-n-butyl titanate, organic acids such as formic acid, acetic acid, and fluorine-modified carboxylic acids, and inorganic acids such as hydrochloric acid and nitric acid. In terms of promoting hydrolysis and the condensation reaction between the perfluoropolyether group-containing silane compound and the silicate oligomer, as well as the storage stability of the coating liquid and the film-forming properties and durability of the coating film, inorganic acids such as hydrochloric acid and nitric acid are preferably used. Regarding the quality of the water derived from the catalyst, pure water including ion-exchanged water and ultrapure water is preferably used from the viewpoint of not containing impurities. The amount of water derived from the catalyst is preferably in the range of 1 to 2 equivalents relative to the hydrolyzable groups contained in the perfluoropolyether group-containing silane compound and the silicate oligomer.

[0023] The perfluoropolyether group-containing silane compound and silicate oligomer are uniformly dissolved in a solvent, followed by the addition of a catalyst. The mixture is stirred for 1 to 24 hours, preferably while maintaining a liquid temperature of approximately 30 to 70°C, to hydrolyze and condense the perfluoropolyether group-containing silane compound and silicate oligomer, thereby preparing a surface modifier stock solution. If the liquid temperature is below 30°C, the hydrolysis and condensation reaction between the perfluoropolyether group-containing silane compound and silicate oligomer tends to be insufficient, which can adversely affect the appearance and performance of the coating film. On the other hand, if the liquid temperature is above 70°C, condensation between the condensed silane compounds tends to proceed more easily, which can adversely affect the stability of the synthesis liquid.

[0024] Here, the reaction liquid preferably contains 1 to 3 mass% of a perfluoropolyether group-containing silane compound, 1.5 to 27 mass% of a silicate oligomer, 30 to 70 mass% of at least one fluorine-based solvent, 20 to 50 mass% of at least one water-soluble organic solvent, 0.01 to 3 mass% of a catalyst, and 1 to 5 mass% of water, relative to the total mass of the reaction liquid.

[0025] By using 30 to 70% by weight of fluorine-based organic solvent and 20 to 50% by weight of water-soluble organic solvent, it is possible to avoid insufficient solubility of the solute components, i.e., perfluoropolyether group-containing silane compound, silicate oligomer, and their hydrolyzates and condensates. Furthermore, using less than 0.01% by weight of catalyst results in insufficient catalytic activity, leading to insufficient condensation reaction of the perfluoropolyether group-containing silane compound and silicate oligomer. Using more than 3% by weight of catalyst can lead to insufficient liquid storage stability and coating performance. Furthermore, using less than 1% by weight of water can slow down reactivity during synthesis, while using more than 5% by weight can lead to poor solubility and uneven coating appearance.

[0026] The resulting reaction liquid of the perfluoropolyether group-containing silane compound and silicate oligomer is diluted with a solvent, preferably a mixed solvent of a fluorine-based solvent and a water-soluble organic solvent in a mass ratio of 50:50 to 70:30, and the diluted concentration of components other than the solvent is preferably adjusted to 0.1 to 3 mass %, thereby obtaining a surface modifier. [Example]

[0027] Next, the present invention will be described with reference to examples.

[0028] Synthesis Example 1 In a 100 mL three-neck flask equipped with a Dimroth condenser, calcium chloride tube, thermometer, stirrer, and heating mantle, add perfluoropolyether allylamine. C3F7O[CF(CF3)CF2O] m CF(CF3)CONHCH2CH=CH2 m: 7 (number average degree of polymerization determined by F-NMR, with some distribution) have) 23.3 g (15.22 mmol) of [number average molecular weight Mn 1531.29] and 11.0 g of 1,3-bis(trifluoromethyl)benzene were charged and stirred, and then 0.08 g (94 μl) of Karstedt catalyst Pt·CH═CHSiMe═OMe═OSiCH═CH was charged. While heating at 80°C, 2.1 g (17.18 mmol) of trimethoxysilane [molecular weight Mw 122.2] was added dropwise to initiate the reaction. After stirring overnight, the mixture was cooled to room temperature to terminate the reaction.

[0029] The reaction mixture was distilled under reduced pressure to obtain 18.1 g (yield: 71.4%) of the target pale yellow transparent perfluoropolyether group-containing silane compound [Ia] [number average molecular weight Mn 1653.49]. C3F7O[CF(CF3)CF2O] m CF(CF3)CONH(CH2)3Si(OCH3)3[Ia] F-NMR (CDCl3, CFCl3) -142.8~143.6ppm; -OC F (CF3)CF2O- -130.4 ppm; -C F (CF3)CONH- -128.6 ppm; CF3C F 2CF2O- -81.6 to -77.9 ppm; CF3CF2C F 2O[CF(C F 3) C F 2O] m C F (C F 3) CONH H-NMR (CDCl3, TMS) δ8.27; CON H CH2CH2CH2Si(OCH3)3 δ3.34~3.49; CONHC H 2CH2CH2Si(OC H 3)3 δ1.70; CONHCH2C H 2CH2Si(OCH3)3 δ0.62; CONHCH2CH2C H 2Si(OCH3)3

[0030] Synthesis Example 2 In a 100 mL three-neck flask equipped with a Dimroth condenser, calcium chloride tube, thermometer, stirrer, and heating mantle, add perfluoropolyether diallylamine. C3F7O[CF(CF3)CF2O] m CF(CF3)CON(CH2CH=CH2)2 m: 7 (number average degree of polymerization determined by F-NMR, with some distribution) have) 17 g (10.82 mmol) of [number average molecular weight Mn 1571.34] and 8 g of 1,3-bis(trifluoromethyl)benzene were charged and stirred, and then 0.08 g (94 μl) of Karstedt catalyst Pt·CH═CHSiMe═OMe═OSiCH═CH was charged. While heating at 80°C, 2.8 g (22.91 mmol) of trimethoxysilane [molecular weight Mw 122.2] was added dropwise to initiate the reaction. After stirring overnight, the mixture was cooled to room temperature to terminate the reaction.

[0031] The reaction mixture was distilled under reduced pressure to obtain 14.2 g (yield: 71.7%) of the target pale yellow transparent perfluoropolyether group-containing silane compound [1b] [number average molecular weight Mn 1815.75]. C3F7O[CF(CF3)CF2O] m CF(CF3)CON[(CH2)3Si(OCH3)3]2[1b] F-NMR (CDCl3, CFCl3) -143.0~-143.8ppm; -OC F (CF3)CF2O- -123.6 to -123.9 ppm; -C F (CF3)CONH- -128.8 ppm; CF3C F 2CF2O- -77.1 to -83.6 ppm; C F 3CF2C F 2O[CF(C F 3)C F 2O] m C F (C F 3)CONH H-NMR(CDCl3,TMS) δ3.38 to 3.71; CON[C H 2CH2CH2Si(OC H 3)3]2 δ1.75; CON[CH2C H 2CH2Si(OCH3)3]² δ0.6; CON[CH2CH2C H 2Si(OCH3)3]2

[0032] Example 1 A flask equipped with a nitrogen seal T-connector, Dimroth condenser, thermometer, stirrer, and heating mantle was charged with 46.2 g of fluorinated solvent C4F9OC2H5 (3M Novec 7200) and 30.8 g of isopropyl alcohol [IPA] (Daishin Chemical IPA). The resulting mixture (60:40 fluorinated organic solvent:water-soluble organic solvent) was stirred at room temperature. Then, 1.1 g (0.67 mmol) of perfluoropolyether-containing silane compound [1a] and 4.30 g (7.45 mmol) of silicate oligomer CHO[Si(OCH3)2O]5CH3 (Mitsubishi Chemical MKC Silicate MS51; molecular weight 576.8) were added and stirred. After confirming a clear solution, 2.0 g of 0.5 M nitric acid was added, heated to 50 °C, and stirred for 1 hour. After the reaction was completed, the mixture was cooled to room temperature and filtered using a membrane filter to obtain 80.98 g (95.9% recovery) of a uniform, transparent coating solution. This coating solution was then diluted 5-fold with a mixed solvent (C4F9OC2H5:IPA=60:40) to prepare a coating solution.

[0033] Example 2 In Example 1, the amount of silicate oligomer was changed to 2.91 g (5.04 mmol), and a coating liquid was prepared from the recovered coating stock solution in an amount of 80.02 g (recovery rate 96.4%), which had a uniform and transparent appearance.

[0034] Example 3 In Example 1, the same amount (0.61 mmol) of perfluoropolyether group-containing silane compound [1b] was used instead of perfluoropolyether group-containing silane compound [1a], and a coating solution was prepared from the coating stock solution, which was dissolved in a uniform and transparent liquid, with a recovered amount of 81.84 g (recovery rate 97.0%).

[0035] Example 4 In Example 3, the same amount (3.88 mmol) of methyl silicate oligomer (MKC Silicate MS56, a product of Mitsubishi Chemical; weight-average molecular weight Mw 1107.6) was used as the silicate oligomer, and a coating solution was prepared from the recovered coating stock solution, which was 81.93 g (recovery rate 97.1%) and had a uniformly dissolved appearance.

[0036] Example 5 In Example 1, the amount of silicate oligomer was changed to 5.80 g (10.05 mmol), and a coating liquid was prepared from the coating stock solution in a recovered amount of 82.11 g (recovery rate 95.6%), with a liquid appearance of a uniformly dissolved liquid.

[0037] Comparative Example 1 A perfluoropolyether group-containing silane compound [1a] was added to a fluorine-based organic solvent (Novec7200) so as to have a concentration of 0.3% by mass, and the mixture was stirred at room temperature for 1 hour to prepare a coating liquid.

[0038] Comparative Example 2 In Example 1, the amount of silicate oligomer was changed to 0.73 g (1.26 mmol), and a coating liquid was prepared from the recovered coating stock solution in an amount of 78.18 g (recovery rate 96.7%), which had a uniform and transparent appearance.

[0039] Comparative Example 3 In Example 1, the amount of silicate oligomer was changed to 1.45 g (2.51 mmol), and a coating liquid was prepared from the recovered coating stock solution in an amount of 78.78 g (recovery rate 96.6%), which had a uniform and transparent appearance.

[0040] Comparative Example 4 In Example 1, the same amount (20.64 mmol) of tetraethoxysilane (tetraethyl orthosilicate, a product of Fujifilm Wako Pure Chemical Industries) was used as the silicate oligomer, and a coating solution was prepared from the coating stock solution, which was dissolved in a uniform, transparent liquid with a recovered amount of 74.98 g (recovery rate 94.4%).

[0041] Comparative Example 5 In Example 1, 5.4 g of Novec 7200 and 91.5 g of IPA were charged into a flask equipped with a nitrogen seal T-connector, a Dimroth condenser, a thermometer, a stirrer, and a heating mantle. The resulting mixture (mixture ratio Novec 7200:IPA = 5.6:94.4) was stirred at room temperature. Then, 1.4 g (0.77 mmol) of perfluoropolyether group-containing silane compound [1b] and 4.0 g (6.93 mmol) of silicate oligomer CHO[Si(OCH)O]CH (MKC Silicate MS51) were added and stirred. After confirming a clear solution, 11.6 g of 0.1 M nitric acid was added, heated to 50 °C, and stirred for 1 hour. A cloudy coating solution containing precipitate was obtained (112.48 g, recovery rate 98.8%). The upper layer of this coating stock solution was collected and used as a coating solution.

[0042] The coating solution obtained in each of the above examples and comparative examples was applied to S1215 glass slides and mirror-polished SUS304 stainless steel plates by immersion. The coating solution was then cured for 2 hours in a thermo-hygrostat at 60°C and 80% RH, followed by rinsing with a fluorine-based solvent. The coating film was then crosslinked by heat treatment at 120°C for 10 minutes to prepare test specimens for performance evaluation. The coating film formed on the glass slide test specimens was evaluated for film-forming properties, haze value, and water / oil repellency. The coating film formed on the stainless steel plate test specimens was also evaluated for water / oil repellency and durability (abrasion resistance).

[0043] The results obtained are shown in Table 1. Film forming property: After forming a coating on the slide glass S1215, the surface Visually confirmed. A uniform coating film is formed on the coated surface without any unevenness such as repelling or flow. If the coating is completely dry, it is considered "good"; if the coating has any defects or significant imperfections, it is considered "good"; When structural color was observed, it was judged as "uneven coating." Haze value: After forming a coating on a slide glass S1215, the haze meter HZ- Using V3 (product of Suga Testing Machinery), JIS corresponding to ISO 14782 The haze value was measured in accordance with K7136. This was used as an evaluation indicator for transparency. Static contact angle: cointegrated interface science Using the Drop Master DM500 manufactured by A 2 μl droplet of pure water or n-hexadecane was placed on the edge of the Slowly drop the liquid onto the coating (surface to be inspected) and let it adhere to the surface. The contact angle of the droplet was measured by the sessile drop method and the θ / 2 method. The analyzed value was taken as the static contact angle. This was used as an evaluation index for water and oil repellency. Dynamic sliding angle: Using Drop Master DM500, pure water contained in the tip of the syringe was Slowly add a 10 μl drop of water or a 7 μl drop of n-hexadecane. and drop onto the coating film (surface to be inspected), and repeat this three times. After the droplets landed, tilt the sample stage and slide. The sliding angle was measured, and the value analyzed by the tangent method was used as the dynamic sliding angle. It was a falling corner. Adhesion strength and droplet removal ability were used as evaluation indices. Here, the low sliding angle of pure water means that dynamic water repellency is immediately achieved. This means that the water sliding performance is high. In addition, the low sliding angle of n-hexadecane is due to the dynamic repellency. This means that it has excellent oil resistance and high stain-resistant properties. Durability (abrasion resistance): Oil-based ink marker on the coated surface of stainless steel plate SUS304 Write the numbers using a ZEBRA marker 1mm, then Then, wipe it off using a JK wiper. and erase the numbers without leaving any trace on the sample. The number of times it took to arrive was measured. This was used as an evaluation index for antifouling properties (abrasion resistance). The more times you erase the marker marks, This means that it has high stain resistance (abrasion resistance). Table 1 TIFF0007777700000001.tif83166

[0044] In addition, an outdoor exposure test was carried out as an evaluation index for the weather resistance of the coating film. The results obtained in Examples 1 to 2 and 5 and Comparative Examples 1 to 3 are shown in Table 2. Weather resistance: In accordance with JIS Z2381, an exposure test site was set up on the roof of a building. The test surface was fixed to the test table at a 45° angle facing south, and pure water or n- The static contact angle of hexadecane was measured. Every two weeks, the test specimen was removed and rinsed with ion-exchanged water. Wipe with a JK wiper, blow with pure water or n- The static contact angle to hexadecane was measured. Table 2 TIFF0007777700000002.tif84158

[0045] Furthermore, a storage stability test was carried out as an index for evaluating the stability of the coating liquid. The results obtained in Examples 1 to 2, 5 and Comparative Example 5 are shown in Table 3. Storage stability test: The prepared coating solution was filled into a screw cap bottle and sealed. Store in a thermostatic chamber set at 40°C for one week. The coating performance was then evaluated. Table 3 TIFF0007777700000003.tif42164

[0046] From the above results, the following can be said: (1) On slide glass substrates treated with the fluorine-containing surface treatment agents of each Example, coating films with excellent static water and oil repellency, dynamic water and oil repellency, and good transparency were formed. Similarly, on stainless steel plate substrates treated in the same manner, coating films with excellent static water and oil repellency, dynamic water and oil repellency, and durability (abrasion resistance) were formed. (2) Examples 1 to 2 and 5 are superior in weather resistance compared to Comparative Examples 1 to 3, which contain a high proportion of the perfluoropolyether group-containing silane compound. (3) In Comparative Example 5, in which a solvent with a low mixing ratio of fluorine-based solvent was used, the performance deteriorated significantly after one week at 40°C, but in Examples 1 to 5, there was no significant difference in performance, and the liquid appearance remained uniform and transparent. [Industrial Applicability]

[0047] The surface modifier of the present invention can be effectively used for surface modification of articles (glass substrates, stainless steel substrates, etc.) exposed to outdoor or sliding environments, and is therefore suitably used for outdoor applications such as automotive and architectural glass, as well as for antifouling applications for articles requiring oil repellency, such as camera lenses and eyeglass lenses.

Claims

1. general formula CF 3 (CF 2 ) m O(C 3 F 6 O) n (C 2 F 4 O) o (CF 2 O) p (C 2 F 4 ) q (CF 2 ) r CONX(CH 2 ) s Si(OR) 3 〔I〕 (wherein m is an integer of 0 to 2, n, o, and p are each an integer of 0 to 50, q and r are each an integer of 0 to 2, s is an integer of 0 to 10, and X is a hydrogen atom or (CH 2 ) s Si(OR) 3 where R is an alkyl group having 1 to 3 carbon atoms) and a silicate oligomer, which is methyl silicate, ethyl silicate, or a mixture thereof, having a weight-average molecular weight Mw of 500 to 1500, in a mass ratio of 40:60 to 10:

90.

2. The perfluoropolyether group-containing silane compound is C 3 F 7 O[CF(CF 3 ) CF 2 O] n CF (CF 3 )CONH(CH 2 ) 3 Si(OHH 3 ) 3 or C 3 F 7 O[CF(CF 3 ) CF 2 O] n CF (CF 3 )CON[(CH 2 ) 3 Si(OHH 3 ) 3 ] 2 2. The surface modifier according to claim 1, wherein

3. A surface modifier according to claim 1, wherein the perfluoropolyether group-containing silane compound and silicate oligomer are dissolved in a mixed solvent of a fluorine-based organic solvent and a water-soluble organic solvent.

4. A surface modifier according to claim 3, wherein the mixed solvent has a mass ratio of the fluorine-containing organic solvent to the water-soluble organic solvent of 50:50 to 70:

30.

5. A surface modifier according to claim 4, wherein the diluted concentration of components other than the solvent is 0.1 to 3 mass %.

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