Perfluoropolyether-containing silane compound, preparation method thereof, surface treating agent based on compound, film and application

Abstract

The invention discloses a silane compound containing perfluoropolyether, a preparation method of the silane compound, a surface treating agent based on the compound, a film and application, and belongs to the technical field of fluorosilicone high polymer materials and surface treatment. A benzene ring structure is introduced to the front end of silane of the perfluoropolyether modified silane compound, the benzene ring has a large space structure, the benzene ring has a pi-pi conjugation effect, the effect of shielding a Si-O-Si bond below can be achieved, contact with alkali can be reduced after film forming, and the compound has four siloxanes, so that the perfluoropolyether modified silane compound can be used for preparing a film. The perfluoropolyether compound is more stably combined with a base material, so that the effect of improving alkali resistance is achieved. An article coated with the perfluoropolyether-based silane compound disclosed by the invention has good hydrophobicity, oleophobicity, smoothness and steel wool wear resistance.

Description

Technical Field

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

[0002] With the rapid popularization of smart phones, tablet computers and car central control devices around the world, consumers require the device screen to provide excellent surface sliding properties when they touch the display panel with their fingers. In addition, the touch panel is easily contaminated by skin oil, sweat, cosmetics, etc. In order to form a functional film with better slipperiness and prevent the adhesion of fingerprints and other dirt on the substrate surface, the researchers used a fluorine-containing polymer compound with high lubricity and high water and oil repellency.

[0003] The film layer has the properties of stain removability, wear resistance and scratch resistance. On the one hand, the perfluoropolyether in the polymer compound has the characteristics of low surface energy and high stability. On the other hand, the siloxane group in the molecule can form a chemical bond by dehydration condensation reaction on the surface of the substrate. The surface treatment agent containing the composition is evenly dispersed on the substrate by spraying or vapor deposition, and heated and cured to form a polymer coating with protective function. Since the thickness of the coating is only a few nanometers, it will not affect the surface appearance and light transmittance of the substrate.

[0004] Although conventional coatings are water- and oil-repellent and have excellent pollutant removability, 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 method for preparing a silane compound containing perfluoropolyether, which method 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 a silane compound containing perfluoropolyether, which has good hydrophobicity, oleophobicity, smoothness, contaminant 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 of perfluoropolyether, and the water contact angle of the film surface reaches 119°; the fourth technical problem to be solved by the present invention is to provide the application of the film of the surface treatment agent of the silane compound of perfluoropolyether for anti-fouling of optical elements.

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

[0007] A silane compound containing perfluoropolyether, the chemical structure of which is shown below:

[0008] ;

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

[0010] ;

[0011] 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;

[0012] X and Y are selected from alkylene groups of 2 to 6 carbon atoms and the following groups:

[0013] , , , ;

[0014] Z is selected from an alkylene group of 2 to 6 carbon atoms.

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

[0016] Furthermore, X is an alkylene group with 3-4 carbon atoms; and Y is an alkylene group with 2-3 carbon atoms.

[0017] Furthermore, the Z is an alkylene group having 2-3 carbon atoms.

[0018] Furthermore, the preparation method of any of the above-mentioned silane compounds containing perfluoropolyether comprises the following steps:

[0019] Step 1: Add Rf-OH and 3-bromopropylene to a mixed solvent, drop an alkali solution into it, and react with a catalyst to obtain compound 1, wherein the structural formula of compound 1 is ;

[0020] 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 ;

[0021] 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 ;

[0022] Step 4: Add compound 3 to alkaline water and heat to react to obtain compound 4, wherein the structural formula of compound 4 is ;

[0023] 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 .

[0024] Furthermore, the alkaline solution is potassium hydroxide or sodium hydroxide aqueous solution; the catalyst is chloroplatinic acid / vinyl siloxane 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; the aminopropyl silane coupling agent is one of aminopropyl trimethoxysilane, bis(trimethoxysilylpropyl)amine, methylaminopropyl trimethoxysilane, and ethylaminopropyl trimethoxysilane.

[0025] Furthermore, the surface treatment agent for any of the above-mentioned perfluoropolyether-containing silane compounds contains 0.01-30 wt% of the perfluoropolyether-containing silane compound, and the remaining components are fluorine solvents; the fluorine solvent is one or more of nonafluorobutyl methyl ether, nonafluorobutyl ethyl ether, tridecafluorohexyl methyl ether, tridecafluorohexyl ethyl ether, and m-ditrifluorotoluene.

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

[0027] Furthermore, the method for preparing a film using the surface treatment agent of the silane compound containing perfluoropolyether is a wet coating method or a vapor deposition method; the wet coating method is to dilute the surface treatment agent to a solid concentration dilution liquid of 0.1 wt%-0.4 wt%, and 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 10-60 min, and the final cooling temperature is room temperature; the vapor deposition method is to prepare the surface treatment agent into a pill, load it on a SiO2-deposited substrate through a vapor deposition machine, and form a uniform surface coating to obtain the film.

[0028] Furthermore, the film can be used as an anti-fouling agent for optical components, including display screens of smartphones, tablets or computers, and anti-fingerprints for car central controls.

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

[0030] (1) The present invention introduces a benzene ring structure at the front end of the silane of the perfluoropolyether modified silane compound. The benzene ring has a larger spatial structure and a π-π conjugation effect between the benzene rings, which can shield the Si-O-Si bond below. After film formation, the contact with the alkali can be reduced. In addition, the compound has four siloxanes, which makes the perfluoropolyether compound more firmly bonded to the substrate, thereby improving the alkali resistance.

[0031] (2) The film of the surface treatment agent of the perfluoropolyether-based silane compound of the polysiloxane structure of the present invention has a water contact angle of 117-119° on its surface. Since it has more siloxane, it is more closely bonded to the substrate, so the water contact angle after the steel wool wear test for 30,000 times is not less than 100°;

[0032] (3) The film of the surface treatment agent based on the perfluoropolyether-based silane compound containing a benzene ring structure of the present invention has a water contact angle of not less than 100° after being tested for 72 h with 2 wt % sodium carbonate and 12 h with 2 wt % sodium hydroxide. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0036] Figure 4 This is the NMR spectrum of compound 5 in Synthesis Example 1. DETAILED DESCRIPTION

[0037] The present invention is further illustrated below in conjunction with specific examples. The examples are implemented based on the technical solutions of the present invention. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

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

[0039] Synthesis example 1

[0040] Step 1:

[0041] Compound 1:

[0042] 100 g of Rf-OH, 6.05 g of 3-bromopropylene, 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 were added to the reaction bottle, and the temperature was raised to 50 °C for 3 h. After post-treatment and purification, 100 g of compound 1 was obtained.

[0043] Step 2:

[0044] Compound 2:

[0045] Add 20.7 g of dimethyl allylmalonate, 116 g of 1,4-bis(dimethylsilyl)benzene, and 0.2 g of chloroplatinic acid / vinylsiloxane complex to a toluene solution (Pt element, 100 ppm) into the reaction flask, and heat to 80 °C for 3 h. Column chromatography was used to separate 31.7 g of compound 2, with the following NMR spectrum: Figure 1 shown.

[0046] Step 3:

[0047] Compound 3:

[0048] Add 78.3 g of compound 1, 10.7 g of compound 2, 200 mL of m-ditrifluorotoluene to the reaction flask, add 30 mg of chloroplatinic acid / vinylsiloxane complex to obtain a toluene solution (Pt single substance, 100 ppm), heat to 120 °C and react for 9 h. After the reaction is completed, add 200 mL of m-ditrifluorotoluene, wash with 80 mL×3 of methanol, and concentrate the fluorine phase to obtain 76 g of compound 3. The NMR spectrum is as follows: 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 to the reaction flask, stir mechanically, heat to 100 °C and react for 3 h. Place in an ice bath, drop hydrochloric acid to neutralize to acidity, extract with 200 mL of ethyl perfluorobutyl ether, wash the fluorine phase with 50 mL×2 acetonitrile, and concentrate to obtain 65 g of compound 4. The NMR spectrum is as follows: Figure 3 shown.

[0052] Step 5:

[0053] Compound 5:

[0054]

[0055] Add 20 g of compound 4 and 40 mL of m-trifluorotoluene to the reaction flask, add 1.4 g of oxalyl fluoride dropwise in an ice bath, return to room temperature and react for 2 h. Add 9.2 g of di(3-trimethoxysilylpropyl)amine and 4.7 g of diisopropylaminoethylamine dropwise, and heat to 50 °C and react for 3 h. Post-treatment and purification gave 15 g of compound 5, with the NMR spectrum as shown Figure 4 shown.

[0056] Example 1

[0057] The synthesized compound 5 was mixed with hydrofluoroether (3M Company, Novec HFE7200) to a concentration of 20% by mass as a surface treatment agent (1); the surface treatment agent was deposited onto chemically strengthened glass by vacuum deposition. -3 Pa, firstly, silicon dioxide is deposited on the chemically strengthened glass with a thickness of 10 nm by electron beam deposition to form a silicon dioxide film, and then the aforementioned surface treatment agent is deposited on each piece of chemically strengthened glass with a thickness of about 8 to 10 nm by vacuum deposition. Then, the chemically strengthened glass with the deposited film is 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) and adjusted to a concentration of 0.1 wt%, thereby preparing a spray liquid (1). Using a commercially available spray coating device, the spray liquid (1) was uniformly sprayed on the chemically strengthened glass at a flow rate of 50 mg / sec and a conveyor line speed of 13 mm / sec. Before coating, the surface of the chemically strengthened glass was subjected to plasma treatment. Then, the chemically strengthened glass with the spray-treated 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 Example 1~2

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

[0063] Comparative surface treatment agent 2': X-71-197 (available from Shin-Etsu Chemical Co., Ltd.).

[0064] A surface treatment layer was formed in the same manner as in Example 1 except that the commercially available reference surface treatment agent 1' or 2' was used instead of Compound 5.

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

[0066] 1. Evaluation of hydrophobicity and oleophobicity

[0067] The surface of the glass substrate sample produced by the coating and baking treatment of the above-mentioned embodiment and comparative example samples was measured using a contact angle meter (SDC-100, manufactured by Dongguan Shengding Precision Instrument Co., Ltd.) to measure the contact angle of the surface treatment layer to water and the contact angle of n-hexadecane. The measurement uncertainty was ±1.3°.

[0068] 2. Determination of Slipperiness

[0069] The dynamic friction coefficient of the product relative to the public paper (Daboai) was tested using a friction coefficient tester (Jinan Nanguang Dynamic and Static Friction Tester, FPT-F1) under the following conditions.

[0070] Contact area: 20 mm × 20 mm;

[0071] Load: 200 g;

[0072] Line speed: 200 mm / min;

[0073] Stroke: 35 mm.

[0074] 3. Wear resistance evaluation

[0075] The water contact angle of the surface treatment layer after rubbing was evaluated using a friction tester (Dongguan Dazhong Instrument Co., Ltd., DZ-204-1) under the following conditions.

[0076] The water contact angle is measured every 3,000 times (the evaluation is terminated when the water contact angle is less than 100 degrees or the steel wool is rubbed for 20,000 times or it is damaged).

[0077] Steel wool: BONSTAR#0000;

[0078] Load: 1 kg / cm 2 ;

[0079] Travel distance: 40 mm;

[0080] Moving speed: 60 rpm.

[0081] The test results of hydrophobicity, oleophobicity and slipperiness are shown in Table 1 below.

[0082] Table 1 Hydrophobicity, oleophobicity and slipperiness

[0083]

[0084] The steel wool wear resistance is shown in Table 2.

[0085] Table 2 Steel wool abrasion resistance

[0086]

[0087] It can be seen from the above examples that the surface treatment agent prepared by the perfluoropolyether silane compound of the present invention enables the glass substrate treated therewith to have excellent anti-fouling, anti-fingerprint, scratch resistance and wear resistance, and its comprehensive performance is better than that of commercially available products.

[0088] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A silane compound containing perfluoropolyether, characterized in that: Its chemical structure is shown below: ； In the structural formula, 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; X and Y are selected from alkylene groups of 2 to 6 carbon atoms and the following groups: 、 、 、 ； Z is selected from an alkylene group of 2 to 6 carbon atoms.

2. The perfluoropolyether-containing silane compound 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 perfluoropolyether-containing silane compound according to claim 1, characterized in that: The X is an alkylene group with 3-4 carbon atoms; and Y is an alkylene group with 2-3 carbon atoms.

4. The perfluoropolyether-containing silane compound according to claim 1, characterized in that: The Z is an alkylene group having 2 to 3 carbon atoms.

5. The method for preparing a silane compound containing perfluoropolyether according to any one of claims 1 to 4, 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 。 6. The method for preparing a silane compound containing perfluoropolyether according to claim 5, characterized in that: The alkaline solution is potassium hydroxide or sodium hydroxide aqueous solution; the catalyst is chloroplatinic acid / vinyl siloxane 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; the aminopropyl silane coupling agent is one of aminopropyl trimethoxysilane, bis(trimethoxysilylpropyl)amine, methylaminopropyl trimethoxysilane, and ethylaminopropyl trimethoxysilane.

7. A surface treatment agent comprising a silane compound containing a perfluoropolyether according to any one of claims 1 to 4, characterized in that: The surface treatment agent contains 0.01-30 wt% of the perfluoropolyether-containing silane compound, 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.

8. A film of the surface treatment agent containing a perfluoropolyether silane compound according to claim 7.

9. The method for preparing a film using a surface treatment agent containing a silane compound of perfluoropolyether according to claim 8, 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 concentration dilution liquid of 0.1 wt%-0.4 wt%, and 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 10-60 min, 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.

10. The use of a film as a surface treatment agent containing a silane compound of perfluoropolyether according to claim 9, 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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