Surface modifier

Abstract

A surface modifier which has, as an effective component, a condensate of a silane compound containing a perfluoropolyether group and a silicate oligomer at a mass ratio of 40:60 to 10:90, the silane compound containing a perfluoropolyether group being a compound represented by the following general formula [1], wherein m is an integer of 0 to 2, preferably 2, n, o, p are each an integer of 0 to 50, preferably 5 to 20, q, 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, R is an alkyl group having 1 to 3 carbon atoms. The surface modifier is excellent in water / oil repellency, stain resistance, weather resistance, durability (abrasion resistance), and also has good coating film transparency and liquid storage stability. CF3(CF2) m O(C3F6O) n (C2F4O) o (CF2O) p (C2F4) q (CF2) r CONX(CH2) s Si(OR)3 〔I〕.

Description

TECHNICAL FIELD

[0001] The present application relates to a surface modifier. More specifically, it relates to a surface modifier which can form a coating film excellent in water- and oil-repellency, and further excellent in stain resistance, weather resistance, durability (abrasion resistance), and in transparency of the coating film, and in storage stability of the coating film. BACKGROUND

[0002] In order to impart slidability, water repellency, stain resistance, and the like to the surface of a glass substrate such as a touch panel, a spectacle lens, a windshield, and the like, a surface modifier using a fluorine-containing compound is employed, and in practice, a silane coupling agent containing a perfluoroalkyl group, a silane coupling agent containing a perfluoropolyether group is mainly used.

[0003] The silane coupling agent containing a perfluoroalkyl group is a rigid single molecular chain having a characteristic of being easily crystallized, and although it becomes a coating film excellent in weather resistance, there are problems in stain resistance and abrasion resistance. In addition, although the perfluoroalkyl group having 8 or more carbon atoms easily exhibits performance, there are reports that isomer compounds having a perfluoroalkyl group having such a carbon atom number are biologically decomposed in the environment, become compounds having relatively high bioaccumulation and environmental concentration, and have concerns about exposure in the process, release and diffusion to the environment from waste, treated substrates, and the like.

[0004] Further, isomer compounds having a perfluoroalkyl group having 8 or more carbon atoms inevitably produce or mix perfluorooctanoic acid having high bioaccumulation in the manufacturing process thereof. Therefore, there is a background that each manufacturing company of such isomer compounds withdraws from the manufacturing thereof or starts to promote replacement with compounds having a perfluoroalkyl group having 6 or less carbon atoms, and the like.

[0005] On the other hand, among the compounds having a perfluoroalkyl group having 6 or less carbon atoms, the crystallinity, melting point, glass transition temperature Tg, and the like are significantly reduced compared to the compounds having 8 or more carbon atoms, and the use environment is greatly affected, and thus sufficient performance required cannot be obtained, and there is also an influence on durability and the like.

[0006] Here, the silane coupling agent containing a perfluoropolyether group is a compound in which an ether bond is introduced in a perfluoroalkyl chain, and is a non-crystalline, oily, soft molecular chain, and thus has water- and oil-repellency, chemical resistance, slidability, stain resistance, mold release properties, and the like, and these properties are industrially utilized, and are widely used as an oil repellent, a mold release agent, a cosmetic, a protective film, and the like for equipment.

[0007] In the case where the fluorine-containing silane compound disclosed in Patent Literature 1 is dissolved in a fluorine-based solvent and the prepared coating liquid is coated onto the surface of glass, by covering the surface with a coating film of a silane coupling agent containing a perfluoropolyether group, the surface free energy can be reduced, and water / oil repellency, stain resistance, mold releasability, and the like can be imparted. However, while the coating film is excellent in performance in the initial stage after coating, the durability (weather resistance, abrasion resistance, mold releasability) is sometimes insufficient, and further improvement in durability is sought.

[0008] In Patent Literature 2, it is proposed to add a fluorine-containing alkoxy silane compound to a silica sol to prepare a coating liquid, and by using the coating liquid, fingerprint adhesion and stain resistance are improved. However, the treatment agent shown here has the following problems in addition to the problem that an insoluble compound is generated after reaction and precipitates, that is, after being coated on a substrate such as glass, the surface has a structural color, which impairs the appearance of the coating film, or the storage stability of the solution is not ideal, and the like.

[0009] Prior Art Documents

[0010] Patent Literature

[0011] Patent Literature 1: WO 2015 / 146861 Al

[0012] Patent Literature 2: Japanese Patent Application Publication No. 2009-51976 SUMMARY

[0013] PROBLEMS TO BE SOLVED BY THE INVENTION

[0014] The present application aims to provide a surface modifier which is excellent in water / oil repellency, stain resistance, weather resistance, durability (abrasion resistance), and which is also excellent in coating film transparency and liquid storage stability.

[0015] MEANS FOR SOLVING THE PROBLEMS

[0016] The above object of the present application is achieved by a surface modifier which contains, as an effective ingredient, a condensate of a silane compound containing a perfluoropolyether group and a silicate oligomer at a mass ratio of 40:60 to 10:90, the silane compound containing a perfluoropolyether group being a compound represented by General Formula [I],

[0017] CF3(CF2) m O(C3F6O) n (C2F4O) o (CF2O) p (C2F4) q (CF2) r CONX(CH2) s Si(OR)3 [I]

[0018] wherein m is an integer of 0 to 2, preferably 2, n, o, p are integers of 0 to 50, preferably 5 to 20, q, r are integers 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, R is an alkyl group having 1 to 3 carbon atoms.

[0019] Inventive Effects

[0020] The surface modifier of the present application uses a silane compound having a perfluoropolyether group having a soft structure, which is less accumulated in a living body and environment, and by adding it to a silicate oligomer having a plurality of adhesion functional groups, it has excellent effects of improving adhesion to a base material, dynamic water repellency, dynamic oil repellency optimization (low sliding angle), weather resistance, and wear resistance, in addition to water and oil repellency. Such effects are considered to be exerted by the following: the dense polysiloxane structure formed between the perfluoropolyether chain formed on the surface and the base material becomes firm adhesion, and the density of the perfluoropolyether chain is adjusted, and the mobility is rich. The surface modifier is prepared into an appropriate concentration by dilution, so that the maintenance of the transparency of the coating film and the liquid storage stability can be ensured. DETAILED DESCRIPTION

[0021] As the silane compound having a perfluoropolyether group, a compound represented by General Formula [I] is used:

[0022] CF3(CF2) m O(C3F6O) n (C2F4O) o (CF2O) p (C2F4) q (CF2) r CONX(CH2) s Si(OR)3 〔I〕

[0023] wherein m is an integer of 0 to 2, preferably 2, n, o, p are integers of 0 to 50, preferably 5 to 20, q, r are integers 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, R is an alkyl group having 1 to 3 carbon atoms.

[0024] As the above compound, for example, the following compounds can be mentioned.

[0025] C3F7O[CF(CF3)CF2O] n CF(CF3)CONH(CH2)3Si(OCH3)3

[0026] C3F7O[CF(CF3)CF2O] nCF(CF3)CON[(CH2)3Si(OCH3)3]2

[0027] C3F7O[CF(CF3)CF2O] n (CF2O) p CONH(CH2)3Si(OCH3)3

[0028] C3F7O[CF(CF3)CF2O] n (CF2O) p CON[(CH2)3Si(OCH2CH2CH3)3]2

[0029] C3F7O(CF2CF2CF2O) n CF2CF2CONH(CH2)3Si(OCH3)3

[0030] C3F7O(CF2CF2CF2O) n CF2CF2CONH(CH2)3Si(OCH2CH3)3

[0031] C2F5O(CF2CF2O) o (CF2O) p CONH(CH2)3Si(OCH3)3

[0032] CF3O(CF2CF2O) o CF2CONH(CH2)3Si(OCH3)3

[0033] The following compounds are preferred:

[0034] C3F7O[CF(CF3)CF2O] n CF(CF3)CONH(CH2)3Si(OCH3)3

[0035] C3F7O[CF(CF3)CF2O] n CF(CF3)CON[(CH2)3Si(OCH3)3]2.

[0036] Examples of silicate oligomers include methyl silicate, ethyl silicate, and mixtures thereof. Silicate oligomers with a weight-average molecular weight (Mw) of 500 to 1500 can be used. If a silicate oligomer with a weight-average molecular weight (Mw) larger than this range is used, it will cause thickening and gelation, thus failing to fully realize its storage stability and inherent water and oil repellency. If a silicate oligomer with a weight-average molecular weight (Mw) smaller than this range is used, uneven coating is likely to occur, and durability will not be fully realized.

[0037] The above silicate oligomer can be used directly, for example, using commercially available products such as MKC SILICATE MS51, MS56 (Mitsubishi Chemical Corporation) as methyl silicate, Ethyl Silicate 40 (Colcoat CO., Ltd.) as ethyl silicate, and EMS-485 (Colcoat CO., Ltd.) as a mixture of methyl silicate and ethyl silicate.

[0038] The silane compound containing a perfluoropolyether group and the silicate oligomer are used in a mass ratio of 40:60 to 10:90, preferably 40:60 to 20:80. When the silane compound containing a perfluoropolyether group is used in a larger proportion than the above range in relation to the silicate oligomer, the appearance of the coating film, the film-forming property, the stain resistance, the weather resistance, the durability (abrasion resistance), and the like are deteriorated, and on the contrary, when it is used in a smaller proportion, not only the water and oil repellency and the stain resistance are reduced, but also the liquid is easily gelled and the liquid storage stability is easily insufficient.

[0039] The silane compound containing a perfluoropolyether group and the silicate oligomer are dissolved together with a catalyst in a solvent in which they are dissolved, preferably a mixed solvent of a fluorine-based organic solvent and a water-soluble organic solvent, and a hydrolysis and condensation reaction is performed to prepare a surface modifier stock solution.

[0040] As the fluorine-based organic solvent, fluorinated alkanes, fluorine alkyl ethers, and the like can be given, and for example, 1,4-bis(trifluoromethyl)benzene, ethyl nonafluorobutyl ether, ethyl nonafluoroisobutyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 1,1,1,2,3,4,4,5,5,5-decafluoropentane, and the like can be given, and a fluorine-based organic solvent having 4 to 8 carbon atoms is preferably used. It can be used directly using commercially available products such as Novec series (3M Company), AE-3000 (AGC), and the like.

[0041] As the water-soluble organic solvent, ketones such as acetone, methyl ethyl ketone, alcohols such as methanol, ethanol, isopropanol, and the like can be used. The water-soluble organic solvent is added in order to obtain the solubility of the silicate oligomer and water from the catalyst.

[0042] The solvent affects the solubility of the silane compound containing a perfluoropolyether group, the silicate oligomer, and the catalyst, the reactivity of the hydrolyzable group, the volatility of the coating liquid, the film-forming property of the coating film, and further the transparency of the coating film, and therefore a mixed solvent of one or more fluorine-based solvents and one or more water-soluble organic solvents is preferably used.

[0043] As the catalyst, organic titanium compounds such as tetra-n-butyl titanate, organic acids such as formic acid, acetic acid, fluorine-modified carboxylic acid, and inorganic acids such as hydrochloric acid, nitric acid can be exemplified. Among the catalysts, from the viewpoint of promoting hydrolysis and promoting condensation of the silane compound containing a perfluoropolyether group and the silicate oligomer, and from the viewpoint of storage stability of the coating liquid, film formability, and durability of the coating film, inorganic acids such as hydrochloric acid and nitric acid are preferably used. With respect to the quality of water from the catalyst, from the viewpoint of not containing impurities, pure water including ion-exchanged water, ultrapure water is preferably used. With respect to the hydrolyzable group contained in the silane compound containing a perfluoropolyether group and the silicate oligomer, the amount of water from the catalyst is preferably in the range of 1 to 2 times the equivalent amount.

[0044] After the silane compound containing a perfluoropolyether group and the silicate oligomer are uniformly dissolved in the solvent, the catalyst is added, and the silane compound containing a perfluoropolyether group and the silate oligomer are allowed to undergo hydrolysis and condensation reaction while being stirred for 1 hour to 24 hours while maintaining the liquid temperature at about 30°C to 70°C, thereby preparing a surface modifier stock solution. When the liquid temperature is 30°C or less, the hydrolysis and condensation reaction of the silane compound containing a perfluoropolyether group and the silate oligomer easily becomes insufficient, and thus easily adversely affects the appearance and properties of the coating film. On the other hand, when the liquid temperature is 70°C or more, condensation easily occurs between the silane compounds after condensation, and thus easily adversely affects the stability of the synthesis liquid.

[0045] Here, the following reaction liquid can be used: 1 to 3% by mass of the silane compound containing a perfluoropolyether group, 1.5 to 27% by mass of the silicate oligomer, 30 to 70% by mass of the fluorine-based solvent composed of at least one or more kinds, 20 to 50% by mass of the water-soluble organic solvent composed of at least one or more kinds, 0.01 to 3% by mass of the catalyst, and 1 to 5% by mass of water, with respect to the total amount of the reaction liquid.

[0046] By making the fluorine-based organic solvent 30 to 70% by mass and the water-soluble organic solvent 20 to 50% by mass, the solubility of the silane compound containing a perfluoropolyether group and the silate oligomer, the hydrolyzate and the condensate thereof as solute components can be prevented from becoming insufficient. In addition, when the catalyst is used in an amount of less than 0.01% by mass, the catalytic performance becomes insufficient, and the condensation reaction of the silane compound containing a perfluoropolyether group and the silate oligomer easily becomes insufficient, and when the catalyst is used in an amount of more than 3% by mass, the liquid storage stability and the coating film properties easily become insufficient. Furthermore, when water is used in an amount of less than 1% by mass, the reactivity during synthesis is sometimes difficult to perform, and when water is used in an amount of more than 5% by mass, it is sometimes difficult to dissolve, and coating unevenness easily occurs in the appearance of the coating film.

[0047] As for the obtained reaction solution of the silane compound and the silicate oligomer containing the perfluoropolyether group, the mixed solvent of the solvent, preferably the fluorine-based solvent and the water-soluble organic solvent, in a mass ratio of 50:50 to 70:30 is used to dilute, preferably to prepare the dilution concentration of the components other than the solvent to 0.1 mass% to 3 mass%, to obtain the surface modifier.

[0048] Example

[0049] Next, the present application will be described with reference to Examples.

[0050] Synthesis Example 1

[0051] In a three-necked flask of 100 mL capacity equipped with a Dimroth condenser, a calcium chloride tube, a thermometer, a stirrer and a mantle heater for heating, perfluoropolyether allylamine [number average molecular weight Mn 1531.29] 23.3 g (15.22 mmol) and 1,3-bis(trifluoromethyl)benzene 11.0 g were added.

[0052] C3F7O[CF(CF3)CF2O] m CF(CF3)CONHCH2CH=CH2

[0053] m: 7 (number average degree of polymerization obtained from F-NMR, having a certain degree of distribution)

[0054] After stirring, Karstedt catalyst Pt • CH2=CHSiMe2OMe2OSiCH=CH2 0.08 g (94 μl) was added, and the reaction was started by heating at 80°C while dropping trimethoxysilane [molecular weight Mw 122.2] 2.1 g (17.18 mmol), and after stirring for one night, the reaction was stopped by cooling to room temperature.

[0055] The reaction mixture was distilled under reduced pressure to obtain the target compound, a perfluoropolyether group-containing silane compound [Ia] [number average molecular weight Mn 1653.49] 18.1 g (yield: 71.4%).

[0056] C3F7O[CF(CF3)CF2O] m CF(CF3)CONH(CH2)3Si(OCH3)3 [Ia]

[0057] F-NMR (CDC13, CFCl3)

[0058] -142.8 to 143.6 ppm; -OC F (CF3)CF2O-

[0059] -130.4 ppm; -CF (CF3)CONH-

[0060] -128.6ppm; CF3C F2 CF2O-

[0061] -81.6 ~ -77.9 ppm;

[0062] CF3CF2C F2 O[CF(C F3 )C F2 O] m C F (C F3 )CONH

[0063] H-NMR (CDC13TMS)

[0064] δ 8.27; CON H CH2CH2CH2Si(OCH3)3

[0065] δ 3.34 ~ 3.49; CONHC H2 CH2CH2Si(OC H3 )3

[0066] δ 1.70; CONHCH2C H2 CH2Si(OCH3)3

[0067] δ 0.62; CONHCH2CH2C H2 Si(OCH3)3

[0068] Synthesis Example 2

[0069] In a three-necked flask of 100 mL capacity equipped with a Dimroth condenser, a calcium chloride tube, a thermometer, a stirring bar and a jacketed heater for heating, perfluoropolyetherdiallylamine [number average molecular weight Mn1571.34] 17 g (10.82 mmol) and 1,3-bis(trifluoromethyl)benzene 8 g were charged.

[0070] C3F7O[CF(CF3)CF2O] m CF(CF3)CON(CH2CH=CH2)2

[0071] m: 7 (number average degree of polymerization determined from F-NMR, having a certain degree of distribution)

[0072] After stirring, Karstedt catalyst Pt-CH2=CHSiMe2OMe2OSiCH=CH2 0.08 g (94 μl) was added, and the reaction was started by heating at 80°C while dropping trimethoxysilane [molecular weight Mw 122.2] 2.8 g (22.91 mmol), and after stirring for one night, the reaction was stopped by cooling to room temperature.

[0073] The reaction mixture was distilled under reduced pressure to obtain the target compound, a silane compound containing a perfluoropolyether group [lb] [number average molecular weight Mn 1815.75] 14.2 g (yield: 71.7%).

[0074] C3F7O[CF(CF3)CF2O] m CF(CF3)CON[(CH2)3Si(OCH3)3]2 [Ib]

[0075] F-NMR (CDC13, CFCl3)

[0076] -143.0 - 143.8 ppm; -OC F (CF3)CF2O-

[0077] -123.6 - 123.9 ppm; -C F (CF3)CONH-

[0078] -128.8 ppm; CF3C F2 CF2O-

[0079] -77.1 - 83.6 ppm;

[0080] C F3 CF2C F2 O[CF(C F3 )C F2 O] m C F (C F3 )CONH

[0081] H-NMR (CDC13, TMS)

[0082] δ 3.38 - 3.71; CON[C H2 CH2CH2Si(OC H3 )3]2

[0083] δ 1.75; CON[CH2C H2 CH2Si(OCH3)3]2

[0084] δ 0.6; CON[CH2CH2C H2 Si(OCH3)3]2

[0085] Example 1

[0086] In a flask equipped with a T-shaped connector for nitrogen sealing, a Dimroth condenser, a thermometer, a stirrer, and a jacketed heater for heating, C4F9OC2H5 (3M product Novec 7200) 46.2 g and isopropyl alcohol [IPA] (Dai-ken Chemicals product IPA) 30.8 g were added in a fluorine-based solvent, and the mixture was stirred at room temperature to prepare a mixed solvent (fluorine-based organic solvent: water-soluble organic solvent = 60:40). To the mixed solvent, silane compound [la] 1.1 g (0.67 mmol) having a perfluoropolyether group and silicate oligomer CH3O[Si(OCH3)20]5CH3 (Mitsubishi Chemical product MKC Silicate MS51; molecular weight Mw 576.8) 4.30 g (7.45 mmol) were added, and stirring was performed. After confirming that it was transparent and dissolved, 2.0 g of 0.5M nitric acid was added, and heating to 50°C and stirring were performed for 1 hour. After the reaction was completed, it was cooled to room temperature, filtered using a membrane filter, and a coating stock solution was obtained, and the recovery amount was 80.98 g (recovery rate 95.9%), and the liquid appearance was uniformly and transparently dissolved. Next, the coating stock solution was diluted 5 times using the mixed solvent (C4F9OC2H5: IPA = 60:40), and a coating solution was prepared.

[0087] Example 2

[0088] In Example 1, the amount of the silicate oligomer was changed to 2.91 g (5.04 mmol), and a coating solution was prepared from the coating stock solution (recovery amount 80.02 g (recovery rate 96.4%), liquid appearance uniformly and transparently dissolved).

[0089] Example 3

[0090] In Example 1, an equal amount (0.61 mmol) of silane compound [lb] having a perfluoropolyether group was used instead of silane compound [la] having a perfluoropolyether group, and a coating solution was prepared from the coating stock solution (recovery amount 81.84 g (recovery rate 97.0%), liquid appearance uniformly and transparently dissolved).

[0091] Example 4

[0092] In Example 3, an equal amount (3.88 mmol) of methyl silicate oligomer (Mitsubishi Chemical product MKC Silicate MS56; weight average molecular weight Mw 1107.6) was used as the silicate oligomer, and a coating solution was prepared from the coating stock solution (recovery amount 81.93 g (recovery rate 97.1%), liquid appearance uniformly and transparently dissolved).

[0093] Example 5

[0094] In Example 1, the amount of silicate oligomer was changed to 5.80 g (10.05 mmol), and a coating liquid was prepared from a coating stock solution (recovery amount 82.11 g (recovery rate 95.6%), liquid appearance had been uniformly dissolved).

[0095] Comparative Example 1

[0096] To a fluorine-based organic solvent (Novec 7200) was added a silane compound containing a perfluoropolyether group [1a] so as to be 0.3 mass%, and a coating liquid was prepared by stirring at room temperature for 1 hour.

[0097] Comparative Example 2

[0098] In Example 1, the amount of silicate oligomer was changed to 0.73 g (1.26 mmol), and a coating liquid was prepared from a coating stock solution (recovery amount 78.18 g (recovery rate 96.7%), liquid appearance had been uniformly and transparently dissolved).

[0099] Comparative Example 3

[0100] In Example 1, the amount of silicate oligomer was changed to 1.45 g (2.51 mmol), and a coating liquid was prepared from a coating stock solution (recovery amount 78.78 g (recovery rate 96.6%), liquid appearance had been uniformly and transparently dissolved).

[0101] Comparative Example 4

[0102] In Example 1, as the silicate oligomer, an equal amount (20.64 mmol) of tetraethoxysilane (Fuji Photo Film and Light Pure Chemicals Products Tetraethyl orthosilicate) was used, and a coating liquid was prepared from a coating stock solution (recovery amount 74.98 g (recovery rate 94.4%), liquid appearance had been uniformly and transparently dissolved).

[0103] Comparative Example 5

[0104] In Example 1, in a flask equipped with a T-shaped connector for nitrogen sealing, a Dimroth condenser, a thermometer, a stirrer, and a jacketed heater for heating, 5.4 g of Novec 7200 and 91.5 g of IPA were added, and a mixed solvent was formed by stirring at room temperature (mixed ratio Novec 7200:IPA = 5.6:94.4). To the mixed solvent was added 1.4 g (0.77 mmol) of a silane compound containing a perfluoropolyether group [1b] and 4.0 g (6.93 mmol) of a silicate oligomer CH3O[Si(OCH3)2O]5CH3(MKC Silicate MS51), and stirring was performed. After confirming that it had been transparently dissolved, 11.6 g of 0.1M nitric acid was added, heating to 50°C was performed, and stirring was performed for 1 hour, and a coating stock solution (recovery amount 112.48 g (recovery rate 98.8%) of white turbidity, precipitate was generated) was obtained. The upper layer of the coating stock solution was collected as a coating liquid.

[0105] In the coating liquid obtained in each of the above examples and comparative examples, a glass slide S1215 and a mirror-finished stainless steel SUS304 were immersed in the coating liquid and coated with the coating liquid, and after being left to stand in a constant-temperature and constant-humidity chamber at 60°C and 80% RH for 2 hours, the coating liquid was washed with a fluorine-based solvent. Then, the coating film was crosslinked by heat treatment at 120°C for 10 minutes, and test pieces for performance evaluation were produced. The coating film formed on the glass slide test piece was evaluated in terms of film formation, haze value, and water / oil repellency. In addition, the coating film formed on the stainless steel test piece was evaluated in terms of water / oil repellency and durability (abrasion resistance).

[0106] The results obtained are shown in Table 1.

[0107] Film formation: After the coating film was formed on the glass slide S1215, the surface thereof was visually confirmed.

[0108] A case where a uniform coating film could be formed without uneven coating such as non-rebound, flow, and the like on the coated surface was judged to be "good", and a case where some defects, obvious texture, and the like occurred in the appearance of the coating film was judged to be "uneven coating".

[0109] Haze value: After the coating film was formed on the glass slide S1215, the haze value was measured using a haze meter HZ-V3 (product of Suga Test Instruments Co., Ltd.) based on JIS K7136 corresponding to ISO 14782.

[0110] As an evaluation index of transparency.

[0111] Static contact angle: Using Drop Master DM500 (manufactured by Republic of Interface Science), 2 μl of a droplet of pure water or n-hexadecane contained in the front end of a syringe was slowly dropped on the coating film (the surface to be inspected), and the contact angle of the droplet adhered to the surface was measured by the droplet method, and the value analyzed by the θ / 2 method was used as the static contact angle.

[0112] As an evaluation index of water / oil repellency.

[0113] Dynamic sliding angle: Using Drop Master DM500, 10 μl of a droplet of pure water or 7 μl of n-hexadecane contained in the front end of a syringe was slowly dropped on the coating film (the surface to be inspected), and the dropping was repeated three times, and after the dropping, the sample stage was inclined, and the inclination angle at which sliding started (sliding angle) was measured, and the value analyzed by the tangent method was used as the dynamic sliding angle.

[0114] As an evaluation index of adhesion and droplet removability.

[0115] Here, a low sliding angle of pure water means that the dynamic water repellency is excellent and the water sliding property is high.

[0116] In addition, the low sliding angle of n-hexadecane means that the dynamic oil repellency is excellent and the stain resistance is high. Durability (abrasion resistance): A number was written on a coated surface of a stainless steel plate SUS304 with an oily ink marker, Mackie 1 mm manufactured by ZEBRA Co., Ltd., and then it was wiped off with a JK Wiper, and the operation was repeated, and the number of times until the number could be erased without leaving a mark on the sample was measured.

[0117] As an evaluation index of stain resistance (abrasion resistance).

[0118] Here, the more the number of times until the mark of the marker was eliminated means the higher the stain resistance (abrasion resistance).

[0119] Table 1

[0120]

[0121] In addition, as an evaluation index of weather resistance of the coating film, an outdoor exposure test was performed. The results obtained in Examples 1 to 2 and 5 and Comparative Examples 1 to 3 are shown in Table 2.

[0122] Weather resistance: Based on JIS Z2381, the exposure test site was set on the roof of a building, and the test surface was set at 45° to the south

[0123] The static contact angle of pure water or n-hexadecane before the test was measured by fixing the test piece on a test stand.

[0124] Every two weeks, the test piece was removed, washed with ion exchange water and wiped with a JK Wiper, and the static contact angle of pure water or n-hexadecane after blowing was measured.

[0125] Table 2

[0126]

[0127] Further, as an evaluation index of the stability of the coating liquid, a storage stability test was performed. The results obtained in Examples 1 to 2 and 5 and Comparative Example 5 are shown in Table 3.

[0128] Storage stability test: The prepared coating liquid was filled into a coil bottle, tightly capped and stored in a constant temperature bath set at 40°C, and the properties of the coating film after storage for 1 week were evaluated.

[0129] Table 3

[0130]

[0131] From the above results, the following points were summarized.

[0132] (1) For the slide glass substrates on which the fluorine-containing surface treatment agent of each embodiment was applied, a coating film having excellent static water / oil repellency, dynamic water repellency, dynamic oil repellency, and good transparency was formed. In addition, even in a stainless steel plate substrate on which the same was applied, a coating film having excellent static water / oil repellency, dynamic water repellency, dynamic oil repellency, and durability (abrasion resistance) was formed.

[0133] (2) The weather resistance of Examples 1 to 2, 5 was excellent compared with Comparative Examples 1 to 3, which contained a silane compound having a perfluoropolyether group in a high proportion.

[0134] (3) For Comparative Example 5, in which the mixing proportion of the solvent using a fluorine-based solvent was low, the performance after 1 week at 40°C deteriorated significantly, but for Examples 1 to 2, 5, there was no great difference in performance, and the liquid appearance also maintained uniform transparency.

[0135] Industrial applicability

[0136] The surface modifier of the present application can be effectively used for surface modification of articles (glass substrates, stainless steel substrates, etc.) exposed to the outdoors or sliding environments, and thus, for example, in addition to outdoor uses such as automotive and architectural glass, it is also suitable for antifouling uses for articles such as camera lenses, eyeglass lenses, and the like, which require oil repellency.

Claims

1. A surface modifier, wherein the active ingredient is a condensation reactant of a silane compound containing a perfluoropolyether group and a silicate oligomer in a mass ratio of 40:60 to 10:

90. in, The silane compound containing perfluoropolyether groups is C3F7O[CF(CF3)CF2O] n CF(CF3)CONH(CH2)3Si(OCH3)3 or C3F7O[CF(CF3)CF2O] n CF(CF3)CON[(CH2)3Si(OCH3)3]2, In the formula, n is an integer from 0 to 50, and the silicate oligomer is methyl silicate, ethyl silicate, or mixtures thereof with a weight-average molecular weight Mw of 500 to 1500. The silane compound containing perfluoropolyether groups and the silicate oligomer are dissolved in a mixed solvent of fluorinated organic solvent and water-soluble organic solvent. The mass ratio of fluorinated organic solvent to water-soluble organic solvent in the mixed solvent is 50:50 to 70:

30.

2. The surface modifier according to claim 1, wherein, For components other than solvents, the dilution concentration is 0.1% to 3% by mass.

Images