A silane compound containing perfluoropolyether, a preparation method thereof, a surface treatment agent, a film and an application based on the compound

Abstract

The present invention discloses a silane compound containing perfluoropolyether, a preparation method thereof, a surface treatment agent, a film and an application based on the compound, belonging to the technical fields of fluorosilicon polymer materials and surface treatment. By introducing a benzene ring structure at the silane front end of the perfluoropolyether-modified silane compound, the benzene ring has a large spatial structure and there is a π-π conjugation effect between benzene rings, which can play a role in shielding the Si-O-Si bond below. After film formation, the contact with alkali can be reduced, and the compound has four siloxanes, making the perfluoropolyether compound more firmly combined with the substrate, thereby having the effect of improving alkali resistance. The article coated with the perfluoropolyether-based silane compound of the present invention has good hydrophobicity, oleophobicity, slipperiness and resistance to steel wool abrasion.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluorosilicon polymer materials and surface treatment, and particularly relates to a silane compound containing perfluoropolyether, a preparation method thereof, a surface treatment agent, a film and an application based on the compound. Background Art

[0002] With the rapid popularization of global smartphones, tablet computers and automotive center control devices, when consumers touch the display panel with their fingers to operate, it is required that the device screen provides excellent surface slidability. And the touch panel is easily contaminated by skin oils, sweats, cosmetics, etc. In order to form a functional film with better smoothness on the substrate surface and prevent the adhesion of dirt such as fingerprints, researchers have adopted fluorine-containing polymer compounds with high lubricity, high water and oil repellency.

[0003] For the film layer with properties such as stain erasability, wear resistance and scratch resistance, on the one hand, it is due to the characteristics of low surface energy and high stability of perfluoropolyether in the polymer compound, and on the other hand, the siloxane groups in the molecule can undergo dehydration condensation reaction on the substrate surface to form chemical bonds and combine. The surface treatment agent containing the composition is uniformly dispersed on the substrate by spraying or vapor deposition, and a polymer coating with a protective function can be formed by heating and curing. Since the thickness of this coating is only a few nanometers, it will not affect the surface appearance and light transmittance of the substrate.

[0004] Although the conventional coating has water and oil repellency and excellent stain erasability, the anti-fouling performance decreases during use. Therefore, the demand for highly wear-resistant coatings is increasing day by day. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide a preparation method of a silane compound containing perfluoropolyether, which is simple to operate and the conditions are mild and easy to control; the second technical problem to be solved by the present invention is to provide a surface treatment agent based on the silane compound containing perfluoropolyether, which has good hydrophobicity, oleophobicity, smoothness, stain erasability and high wear resistance; the third technical problem to be solved by the present invention is to provide a film of the surface treatment agent of the silane compound containing perfluoropolyether, and the water contact angle on the surface of the film reaches 119°; the fourth technical problem to be solved by the present invention is to provide an application of the film of the surface treatment agent of the silane compound containing perfluoropolyether, which is used for anti-fouling of optical elements.

[0006] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0007] A silane compound containing perfluoropolyether, the chemical structural formula of which is shown as the following formula:

[0008] ;

[0009] In the structural formula, Rf is a general formula structural part:

[0010] ;

[0011] Wherein, m is an integer from 5 to 100, n is an integer from 5 to 100, p is an integer from 0 to 100, q is an integer from 0 to 100, the sum of m + n + p + q = 10 - 105, each repeating unit is linear or branched, and the respective repeating units are arranged randomly, d is an integer from 1 to 3, C d F 2d units are linear or branched;

[0012] X and Y are selected from alkylene groups having 2 to 6 carbons and the following groups:

[0013] , , , ;

[0014] Z is selected from alkylene groups having 2 to 6 carbons.

[0015] Furthermore, in the molecular formula of the said Rf, p and q are 0, m and n are integers from 30 to 60, and d is 1.

[0016] Furthermore, the said X is an alkylene group having 3 to 4 carbons; Y is an alkylene group having 2 to 3 carbons.

[0017] Furthermore, the said Z is an alkylene group having 2 to 3 carbons.

[0018] Furthermore, for the preparation method of the perfluoropolyether-containing silane compound described above, the preparation steps are as follows:

[0019] Step 1: Add Rf-OH and 3-bromopropene into a mixed solvent, dropwise add an alkali solution, and obtain Compound 1 under the action of a catalyst, where the structural formula of Compound 1 is ;

[0020] Step 2: React dimethyl allylmalonate and 1,4-bis(dimethylsilyl)benzene under the action of a catalyst, and obtain Compound 2 by column chromatography separation, where the structural formula of Compound 2 is ;

[0021] Step 3: Convert Compound 1 and Compound 2 into Compound 3 under the action of a catalyst, where the structural formula of Compound 3 is ;

[0022] Step 4: Add Compound 3 into alkaline water and heat it for reaction to obtain Compound 4, where the structural formula of Compound 4 is ;

[0023] Step 5: React compound 4 with an acyl halide reagent to form the corresponding perfluoropolyether acyl halide, and then react it with an aminopropylsilane coupling agent to obtain compound 5, where the structural formula of compound 5 is .

[0024] Furthermore, the alkali solution is potassium hydroxide or an aqueous solution of sodium hydroxide; the catalyst is chloroplatinic acid / vinylsiloxane complex; the mixed solvent is composed of an organic solvent and a fluorinated solvent. The organic solvent is one or more of tetrahydrofuran, ethylene glycol dimethyl ether, and 1,4-dioxane; the fluorinated solvent is one or more of nonafluorobutyl methyl ether, nonafluorobutyl ethyl ether, tridecafluorohexyl methyl ether, tridecafluorohexyl ethyl ether, and meta-bis(trifluoromethyl)benzene; the acyl halide reagent is one of oxalyl chloride and thionyl chloride; the aminopropylsilane coupling agent is one of aminopropyltrimethoxysilane, bis(trimethoxysilylpropyl)amine, methylaminopropyltrimethoxysilane, and ethylaminopropyltrimethoxysilane.

[0025] Furthermore, for the surface treatment agent containing the perfluoropolyether-containing silane compound described above, the surface treatment agent contains 0.01 - 30 wt% of the perfluoropolyether-containing silane compound, and the remaining components are fluorinated solvents; the fluorinated solvents are one or more of nonafluorobutyl methyl ether, nonafluorobutyl ethyl ether, tridecafluorohexyl methyl ether, tridecafluorohexyl ethyl ether, and meta-bis(trifluoromethyl)benzene.

[0026] Furthermore, a thin film of the surface treatment agent containing the perfluoropolyether-containing silane compound.

[0027] Furthermore, a method for preparing a thin film from the surface treatment agent containing the perfluoropolyether-containing silane compound. This method is a wet coating method or a vapor deposition method; for the wet coating method, the surface treatment agent is diluted to a solid content dilution with a concentration of 0.1 wt% - 0.4 wt%, and then coated or sprayed on a plasma-treated substrate and baked, and after cooling, the thin film is obtained, where the baking temperature is 80 - 150 °C, the baking time is 10 - 60 min, and the final temperature of cooling is room temperature; for the vapor deposition method, the surface treatment agent is made into a pill, and through an evaporation coater, it is loaded on a substrate deposited with SiO2 to form a uniform surface coating, and thus the thin film is obtained.

[0028] Furthermore, the thin film can be used for anti-fouling of optical elements, including anti-fingerprinting of the display screens of smartphones, tablets, or computers, and the central control of automobiles.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] (1) In the present invention, a benzene ring structure is introduced at the silane front end of the perfluoropolyether-modified silane compound. The benzene ring has a relatively large spatial structure and there is a π-π conjugation effect between benzene rings, which can play a role in shielding the Si-O-Si bonds below. After film formation, the contact with alkali can be reduced. Moreover, this compound has four siloxanes, making the perfluoropolyether compound bind more firmly to the substrate, thus having the effect of improving alkali resistance.

[0031] (2) For the film of the surface treatment agent based on the perfluoropolyether-based silane compound with a polysiloxane structure of the present invention, the water contact angle on its surface is 117 - 119°. Due to having more siloxanes and binding more to the substrate, the water contact angle after 30,000 wire wool abrasion tests is not lower than 100°.

[0032] (3) For the film of the surface treatment agent based on the perfluoropolyether-based silane compound with a benzene ring structure of the present invention, the water contact angle after 72 h of resistance to 2 wt% sodium carbonate test and 12 h of resistance to 2 wt% sodium hydroxide is not lower than 100°. Description of the Drawings

[0033] Figure 1 It is the NMR spectrum of compound 2 in Synthesis Example 1;

[0034] Figure 2 It is the NMR spectrum of compound 3 in Synthesis Example 1;

[0035] Figure 3 It is the NMR spectrum of compound 4 in Synthesis Example 1;

[0036] Figure 4 It is the NMR spectrum of compound 5 in Synthesis Example 1. Specific Embodiments

[0037] The following combines specific embodiments to further clarify the present invention. The embodiments are implemented on the premise of the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0038] In the following embodiments, Rf is a Z-type monofunctional perfluoroether compound with a molecular weight of 4000.

[0039] Synthesis Example 1

[0040] Step 1:

[0041] Compound 1:

[0042] Add 100 g of Rf-OH, 6.05 g of 3-bromopropene, 4.2 g of potassium hydroxide, 4.2 g of water, 1.6 g of tetrabutylammonium bromide, 150 mL of ethyl perfluorobutyl ether (Novec 7200, 3M Company), and 50 mL of N, N-dimethylformamide into a reaction flask, and heat to 50 °C for reaction for 3 h. After post-treatment and purification, 100 g of compound 1 is obtained.

[0043] Step 2:

[0044] Compound 2:

[0045] Add 20.7 g of dimethyl allylmalonate and 116 g of 1,4-bis(dimethylsilyl)benzene into a reaction flask, add 0.2 g of chloroplatinic acid / vinylsiloxane complex to obtain a toluene solution (calculated as Pt element, 100 ppm), and heat to 80 °C for reaction for 3 h. After column chromatography separation, 31.7 g of compound 2 is obtained, and the NMR spectrum is as Figure 1 shown.

[0046] Step 3:

[0047] Compound 3:

[0048] Add 78.3 g of compound 1, 10.7 g of compound 2, and 200 mL of m-bis(trifluoromethyl)benzene into a reaction flask, add 30 mg of chloroplatinic acid / vinylsiloxane complex to obtain a toluene solution (calculated as Pt element, 100 ppm), and heat to 120 °C for reaction for 9 h. After the reaction is completed, add another 200 mL of m-bis(trifluoromethyl)benzene, wash with 80 mL × 3 of methanol, and concentrate the fluorine phase to obtain 76 g of compound 3, and the NMR spectrum is as Figure 2 shown.

[0049] Step 4:

[0050] Compound 4:

[0051] Add 70 g of compound 3, 15 g of sodium hydroxide, and 200 mL of water into a reaction flask, stir mechanically and heat to 100 °C for reaction for 3 h. Cool in an ice bath, dropwise add hydrochloric acid to neutralize to acidity, extract with 200 mL of ethyl perfluorobutyl ether, wash the fluorine phase with 50 mL × 2 of acetonitrile, and concentrate to obtain 65 g of compound 4, and the NMR spectrum is as Figure 3 shown.

[0052] Step 5:

[0053] Compound 5:

[0054]

[0055] Add 20 g of Compound 4 and 40 mL of m-bis(trifluoromethyl)benzene to a reaction flask, and dropwise add 1.4 g of oxalyl fluoride thereto in an ice bath. Then, return the reaction mixture to room temperature and react for 2 h. Drop in 9.2 g of bis(3-trimethoxysilylpropyl)amine and 4.7 g of N,N-diisopropylethylamine, and heat the reaction mixture to 50 °C and react for 3 h. After post-treatment and purification, 15 g of Compound 5 is obtained. The NMR spectrum is as Figure 4 shown.

[0056] Example 1

[0057] The synthesized Compound 5 and hydrofluoroether (3M Company, Novec HFE7200) were adjusted to a mass concentration of 20% to prepare a surface treatment agent (1); the above surface treatment agent was deposited on chemically strengthened glass by vacuum deposition. Under a vacuum pressure of less than 4×10 -3 Pa, first, silicon dioxide was deposited on the chemically strengthened glass to a thickness of 10 nm by electron beam deposition to form a silicon dioxide film, and then the aforementioned surface treatment agent with a thickness of about 8 - 10 nm was deposited on each piece of chemically strengthened glass by vacuum deposition. Then, the chemically strengthened glass with the deposited film was placed in an environment of 60% humidity and 70 °C for 2 hours for curing to form a surface treatment layer.

[0058] Example 2

[0059] Preparation of surface treatment agent and formation of cured film

[0060] The surface treatment agent (1) of Example 1 was dissolved in ethyl perfluorobutyl ether (Novec 7200, 3M Company) to prepare a concentration of 0.1 wt% to obtain a spraying solution (1). Using a commercially available spraying and coating device, the spraying solution (1) was uniformly sprayed and coated on the chemically strengthened glass at a flow rate of 50 mg / sec and a conveying line speed of 13 mm / sec. Before coating, the surface of the chemically strengthened glass needs to be plasma-treated. Then, the chemically strengthened glass with the sprayed treatment film was placed in an environment of 60% humidity and 70 °C for 2 h for curing to form a surface treatment layer.

[0061] Comparative Examples 1 - 2

[0062] Control surface treatment agent 1': Optool UD509 (purchased from Daikin Company);

[0063] Control surface treatment agent 2': X-71-197 (purchased from Shin-Etsu Chemical Company).

[0064] Except for using the above commercially available control surface treatment agents 1' or 2' to replace Compound 5, the surface treatment layer was formed in the same manner as described in Example 1.

[0065] Next, the surface treatment layer formed on the substrate surface was evaluated by the following method, and the results are shown in Table 1-2.

[0066] 1. Evaluation of hydrophobic and oleophobic properties

[0067] For the surfaces of the glass substrate samples produced by coating and baking the samples of the above-mentioned examples and comparative examples, a contact angle measuring instrument (SDC-100, manufactured by Dongguan Shengding Precision Instruments Co., Ltd.) was used to measure the contact angle of the surface treatment layer with water and the contact angle with n-hexadecane. The measurement uncertainty was ±1.3°.

[0068] 2. Measurement of slipperiness

[0069] Using a friction coefficient instrument (Jinan Nanguang Dynamic and Static Friction Tester, FPT-F1), the dynamic friction coefficient with respect to office paper (Double A) was measured under the following conditions.

[0070] Contact area: 20 mm × 20 mm;

[0071] Load: 200 g;

[0072] Linear velocity: 200 mm / min;

[0073] Stroke: 35 mm.

[0074] 3. Evaluation of abrasion resistance

[0075] Using a friction testing machine (Dongguan Dazhong Instruments Co., Ltd., DZ-204-1), the water contact angle of the surface treatment layer after friction was evaluated under the following conditions.

[0076] Every 3000 reciprocating times, the water contact angle was measured (the evaluation was terminated when the water contact angle was less than 100 degrees or after 20000 times of friction or when the steel wool was damaged).

[0077] Steel wool: BONSTAR#0000;

[0078] Load: 1 kg / cm 2 ;

[0079] Moving stroke: 40 mm;

[0080] Moving speed: 60 rpm.

[0081] The test results of hydrophobic and oleophobic properties and slipperiness are shown in Table 1 below.

[0082] Table 1 Hydrophobic and oleophobic properties and slipperiness

[0083]

[0084] The wire wool abrasion resistance is as shown in Table 2 below.

[0085] Table 2 Wire wool abrasion resistance

[0086]

[0087] As can be seen from the above embodiments, the surface treatment agent prepared from the perfluoropolyether silane compound of the present invention endows the glass substrate treated therewith with excellent anti-fouling, anti-fingerprint, scratch resistance and wear resistance, and its comprehensive performance is superior to that of commercially available products.

[0088] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a silane compound containing perfluoropolyether, characterized in that: The preparation steps are as follows: Step 1: Add Rf-OH and 3-bromopropylene to a mixed solvent, add a base solution dropwise, and obtain compound 1 through the action of a catalyst, wherein the structural formula of compound 1 is Step 2: reacting dimethyl allylmalonate and 1,4-bis(dimethylsilyl)benzene in the presence of a catalyst, and separating by column chromatography to obtain compound 2, wherein the structural formula of compound 2 is Step 3: Compound 1 and Compound 2 are converted into Compound 3 under the action of a catalyst, wherein the structural formula of Compound 3 is Step 4: Add compound 3 to alkaline water and heat to react to obtain compound 4, wherein the structural formula of compound 4 is Step 5: Compound 4 is reacted with an acyl halide reagent to generate the corresponding perfluoropolyether acyl halide, and then reacted with an aminopropylsilane coupling agent to obtain compound 5, wherein the structural formula of compound 5 is In the structural formula of the prepared compound, Rf is the general structural part: Wherein, m is an integer of 5-100, n is an integer of 5-100, p is an integer of 0-100, q is an integer of 0-100, the sum of m+n+p+q=10-105, each repeating unit is a straight chain or branched chain, each repeating unit is arranged irregularly, d is an integer of 1-3, C d F 2d The units are linear or branched.

2. The method for preparing a silane compound containing perfluoropolyether according to claim 1, characterized in that: In the molecular formula of Rf, p and q are 0, m and n are integers of 30-60, and d is 1.

3. The method for preparing a silane compound containing perfluoropolyether according to claim 1, characterized in that: The alkaline solution is potassium hydroxide or sodium hydroxide aqueous solution; the catalyst is chloroplatinic acid / vinylsiloxane complex; the mixed solvent is composed of an organic solvent and a fluorine-containing solvent, the organic solvent is one or more of tetrahydrofuran, ethylene glycol dimethyl ether, and 1,4-dioxane; the fluorine-containing solvent is one or more of nonafluorobutyl methyl ether, nonafluorobutyl ethyl ether, tridecafluorohexyl methyl ether, tridecafluorohexyl ethyl ether, and m-ditrifluorotoluene; the acyl halide reagent is one of oxalyl chloride and dichlorothionyl.

4. The surface treatment agent of the silane compound containing perfluoropolyether prepared by the preparation method of the silane compound containing perfluoropolyether according to claim 1, characterized in that: The surface treatment agent contains 0.01-30wt% of the silane compound containing perfluoropolyether, and the remaining components are fluorine solvents; the fluorine solvents are one or more of nonafluorobutyl methyl ether, nonafluorobutyl ethyl ether, tridecafluorohexyl methyl ether, tridecafluorohexyl ethyl ether, and m-ditrifluorotoluene. 5 . A film of the surface treatment agent containing a perfluoropolyether silane compound according to claim 4 .

6. A method for preparing a film of a surface treatment agent containing a silane compound of perfluoropolyether as claimed in claim 5, characterized in that: The method is a wet coating method or a vapor deposition method; the wet coating method is to dilute the surface treatment agent to a solid content concentration diluent of 0.1wt%-0.4wt%, then coat or spray it on a plasma-treated substrate for baking, and obtain the film after cooling, wherein the baking temperature is 80-150°C, the baking time is 10-60min, and the final cooling temperature is room temperature; the vapor deposition method is to prepare the surface treatment agent into pills, load it on a SiO2-deposited substrate through a vapor deposition machine, and form a uniform surface coating to obtain the film.

7. An application of a film of a surface treatment agent containing a silane compound of perfluoropolyether as claimed in claim 5, characterized in that: The film is used as an anti-fouling agent for optical components, including display screens of smartphones, tablets or computers, and anti-fingerprints for automobile central controls.

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