阅读说明：本技术 一种全氟聚醚硅氧烷产品的制备方法及其产品在超疏水型防指纹涂层中的应用 (Preparation method of perfluoropolyether siloxane product and application of perfluoropolyether siloxane product in super-hydrophobic anti-fingerprint coating ) 是由 李永斌 于 2021-10-29 设计创作，主要内容包括：本发明公开一种全氟聚醚硅氧烷产品的制备方法及其产品在超疏水型防指纹涂层中的应用,属于含氟聚硅氧烷新材料技术领域,该方法以三氯硅烷为起始反应原料,经与格氏试剂Ⅰ反应制得中间产物Ⅰ；通过中间产物Ⅰ与低聚全氟聚醚醇反应制得中间产物Ⅱ；通过中间产物Ⅱ与三氯硅烷做硅氢加成反应制得中间产物Ⅲ；通过中间产物Ⅲ与格氏试剂Ⅱ反应得到中间产物Ⅳ；通过中间产物Ⅳ与三氯硅烷的重复硅氢加成反应制得中间产物Ⅴ；最后将中间产物Ⅴ与甲醇或乙醇反应,制得全氟聚醚硅氧烷化合物。该方法以低聚全氟聚醚代替高聚全氟聚醚,同时降低合成难度和生产成本。以本发明制备的全氟聚醚硅氧烷化合物经配方制成的超疏水型防指纹涂层,与基材的粘连性极佳且耐摩耐久性能优异,可应用于手机触摸屏及高端数码产品、半导体等行业。(The invention discloses a preparation method of a perfluoropolyether siloxane product and application of the perfluoropolyether siloxane product in a super-hydrophobic anti-fingerprint coating, belonging to the technical field of novel fluorine-containing polysiloxane materials, wherein trichlorosilane is used as an initial reaction raw material and reacts with a Grignard reagent I to prepare an intermediate product I; preparing an intermediate product II by reacting the intermediate product I with oligomeric perfluoropolyether alcohol; intermediate product III is prepared by the hydrosilylation reaction of intermediate product II and trichlorosilane; obtaining an intermediate product IV by reacting the intermediate product III with a Grignard reagent II; preparing an intermediate product V through repeated hydrosilylation reaction of the intermediate product IV and trichlorosilane; and finally, reacting the intermediate product V with methanol or ethanol to prepare the perfluoropolyether siloxane compound. The method replaces high-polymer perfluoropolyether with low-polymer perfluoropolyether, and simultaneously reduces the synthesis difficulty and the production cost. The super-hydrophobic fingerprint-resistant coating prepared from the perfluoropolyether siloxane compound prepared by the invention has excellent adhesion with a base material and excellent wear resistance and durability, and can be applied to industries such as mobile phone touch screens, high-end digital products, semiconductors and the like.)

1. A method for preparing a perfluoropolyether siloxane compound, comprising the steps of:

(1) adding a Grignard reagent I, a catalyst and an organic base into a reactor under a protective gas atmosphere, then dropwise adding trichlorosilane into the reactor, stirring and reacting to obtain a mixed solution a after the reaction is finished, and performing post-treatment on the mixed solution a to obtain an intermediate product I, wherein the intermediate product I is allyl trichlorosilane; the Grignard reagent I is allyl chloride or allyl bromide;

(2) under the atmosphere of protective gas, adding an intermediate product I, perfluoropolyether alcohol, organic base and a nucleophilic reagent into a reactor, stirring at 50-70 ℃ and reacting to obtain a mixed solution b after the reaction is finished, and performing post-treatment on the mixed solution b to obtain an intermediate product II, wherein the structural formula of the intermediate product II is shown as the formula (A):

（A）

wherein PFPE is a perfluoropolyether group;

(3) under the atmosphere of protective gas, adding an intermediate product II and a catalyst into a reactor, dropwise adding trichlorosilane at 90-120 ℃, stirring and reacting to obtain a mixed solution c after the reaction is finished, and performing post-treatment on the mixed solution c to obtain an intermediate product III, wherein the structural formula of the intermediate product III is shown as a formula (B):

（B）

wherein PFPE is a perfluoropolyether group;

(4) adding an intermediate product III into a reactor under the atmosphere of protective gas, dropwise adding a Grignard reagent II solution at 0-10 ℃, stirring at room temperature, reacting to obtain a mixed solution d after the reaction is finished, and performing post-treatment on the mixed solution d to obtain an intermediate product IV, wherein the structural formula of the intermediate product IV is shown as the formula (C):

（C）

wherein PFPE is a perfluoropolyether group;

the Grignard reagent II is allyl magnesium bromide or allyl magnesium chloride;

(5) adding an intermediate product IV and a catalyst into a reactor in a protective gas atmosphere, dropwise adding trichlorosilane at 90-120 ℃, stirring and reacting to obtain a mixed solution e after the reaction is finished, and performing post-treatment on the mixed solution e to obtain an intermediate product V, wherein the structural formula of the intermediate product V is shown as a formula (D):

（D）

wherein PFPE is a perfluoropolyether group;

(6) adding an intermediate product V into a reactor under a protective gas atmosphere, dripping an organic alkali solution at the temperature of 80-100 ℃, stirring and reacting to obtain a mixed solution f after the reaction is finished, and performing post-treatment on the mixed solution f to obtain a perfluoropolyether siloxane compound, wherein the structural formula of the perfluoropolyether siloxane compound is shown as the formula (E):

（E）

wherein PFPE is a perfluoropolyether group, R is-OCH₃or-OCH₂CH₃。

2. The method for producing a perfluoropolyether siloxane compound according to claim 1, characterized in that the catalyst in step (1) is cuprous chloride; the organic base is one of triethylamine and tri-n-propylamine; the molar ratio of the Grignard reagent I to the catalyst to the organic base is 1 to (1-1.3); the molar ratio of the Grignard reagent I to the trichlorosilane is 1: 1-1.5.

3. The method for preparing a perfluoropolyether siloxane compound according to claim 2, wherein the molar ratio of the intermediate product I to the perfluoropolyether alcohol in step (2) is 1: 3 to 3.6; the organic base is potassium tert-butoxide, and the nucleophilic reagent is tert-butanol; the molar ratio of the potassium tert-butoxide to the perfluoropolyether alcohol is (1-1.3) to 1; taking the mass sum of the intermediate product I, the perfluoropolyether alcohol and the potassium tert-butoxide as the total mass, wherein the addition amount of the tert-butanol is calculated by adding not less than 1mL of tert-butanol in every 0.5g of the total mass.

4. The method for producing a perfluoropolyether siloxane compound according to claim 3, characterized in that the catalyst in step (3) is an isopropyl alcohol solution of chloroplatinic acid; the molar ratio of the intermediate product II to the chloroplatinic acid is (10000-30000) to 1; the molar ratio of the intermediate product II to the trichlorosilane is 1: 1-1.3.

5. The method for producing a perfluoropolyether siloxane compound according to claim 4, wherein the molar ratio of the intermediate III to the Grignard reagent II in the step (4) is 1: 3 to 3.5.

6. The method for producing a perfluoropolyether siloxane compound according to claim 5, characterized in that the catalyst in step (5) is an isopropyl alcohol solution of chloroplatinic acid; the molar ratio of the intermediate product IV to trichlorosilane is 1: 3-4.5.

7. The method for producing a perfluoropolyether siloxane compound according to claim 6, wherein the organic base in step (6) is one of triethylamine and pyridine; the organic alkali solution is prepared by dissolving organic alkali in methanol or ethanol; the molar ratio of the intermediate product V to the organic alkali is 1: 9-11.7.

8. A perfluoropolyether siloxane product prepared by the preparation method of any one of claims 1 to 7.

9. Use of the perfluoropolyether siloxane product of claim 8 in an ultrahydrophobic anti-fingerprint coating.

10. A preparation method of a super-hydrophobic fingerprint-resistant coating is characterized by comprising the following steps: diluting the perfluoropolyether siloxane product to 0.2-0.5 wt% by using a diluent to obtain a diluted solution, then adding a surface treating agent into the diluted solution, uniformly stirring, finally adjusting the pH of the solution to 3.5-5 by using an organic acid to obtain the super-hydrophobic anti-fingerprint coating, coating the coating on a base material, and curing at the temperature of 110-150 ℃ to form a film to obtain the super-hydrophobic anti-fingerprint coating;

the perfluoropolyether siloxane product is the perfluoropolyether siloxane product of claim 8; the molar ratio of the perfluoropolyether siloxane product to the surface treating agent is 1: 1-1.3; the surface treating agent is a mixture of an intermediate product I and isopropyl acetate, and the molar ratio of the intermediate product I to the isopropyl acetate is 1: 1-2;

the diluent is hydrofluoroether and trifluorotrichloroethane, and the hydrofluoroether is HFE-7100 or HFE-7200.

Technical Field

The invention belongs to the technical field of new fluorine-containing polysiloxane materials, and particularly relates to a preparation method of a perfluoropolyether siloxane product and application of the perfluoropolyether siloxane product in a super-hydrophobic anti-fingerprint coating.

Background

With the intensive research on hydrophobic coatings, the requirements of people on the coatings are higher and higher. According to different application scenes, the synthesis of coatings with specific functions has become a trend of hydrophobic industry in the future, such as antifouling hydrophobic coatings applied to the surfaces of substrates of touch screens of digital products, semiconductors, automobile windshields and the like. This is because substrates such as glass, which are often touched, are easily stained with sweat and stains, and are not easily cleaned after staining, and the surface of the substrate may be scratched by a cleaning process with a specific cleaning agent.

The fluorine-silicon compound is widely applied to the surfaces of base materials such as glass, plastic parts, aluminum materials and the like as an anti-fingerprint coating, thereby achieving the aim of preventing fouling. At present, the anti-fingerprint coating technology of fluorine-silicon compounds is monopolized abroad, the problems of complex and harsh process and higher cost exist, and most of fluorine-silicon compounds used in China are C₈A perfluorinated polycarbochain compound. But due to C₈Perfluorocarbon chain compounds have serious harm factors to human bodies and the environment, and fluorosilicone compounds synthesized by the perfluorocarbon chain compounds are difficult to degrade, have poor hydrophobic and wear-resistant properties, and are limited in practical application.

The prior fluorine-silicon fingerprint inhibitor is mostly synthesized by perfluoropolyether or perfluoropolyether end group modified compounds, such as: patent CN102666759A, patent CN107698768A, patent CN101501046A and the like all use perfluoropolyether or perfluoropolyether end group modified substances as starting materials, and the perfluoropolyether end group modified substances react with double bond compounds to synthesize perfluoropolyether alkenyl compounds, and then the perfluoropolyether alkenyl compounds and hydrogen-containing silicon bond compounds are subjected to hydrosilylation to prepare perfluoropolyether siloxane compounds. However, the perfluoropolyether used in the compounds is a macromolecular substance, and the synthesis of the perfluoropolyether requires a harsh environment and high cost, so that the anti-fingerprint coating with low cost, high hydrophobicity and high wear resistance needs to be developed.

Disclosure of Invention

Aiming at the problems and the defects in the prior art, the invention aims to provide a preparation method of a perfluoropolyether siloxane product and application of the perfluoropolyether siloxane product in a super-hydrophobic anti-fingerprint coating.

Based on the purpose, the invention adopts the following technical scheme:

the invention provides a preparation method of a perfluoropolyether siloxane compound, which comprises the following steps:

(1) adding a Grignard reagent I, a catalyst and an organic base into a reactor under a protective gas atmosphere, then dropwise adding trichlorosilane into the reactor, stirring and reacting to obtain a mixed solution a after the reaction is finished, and performing post-treatment on the mixed solution a to obtain an intermediate product I, wherein the intermediate product I is allyl trichlorosilane; the Grignard reagent I is allyl chloride or allyl bromide;

(2) under the atmosphere of protective gas, adding an intermediate product I, perfluoropolyether alcohol, organic base and a nucleophilic reagent into a reactor, stirring at 50-70 ℃ and reacting to obtain a mixed solution b after the reaction is finished, and performing post-treatment on the mixed solution b to obtain an intermediate product II, wherein the structural formula of the intermediate product II is shown as the formula (A):

（A）

wherein PFPE is a perfluoropolyether group;

(3) under the atmosphere of protective gas, adding an intermediate product II and a catalyst into a reactor, dropwise adding trichlorosilane at 90-120 ℃, stirring and reacting to obtain a mixed solution c after the reaction is finished, and performing post-treatment on the mixed solution c to obtain an intermediate product III, wherein the structural formula of the intermediate product III is shown as a formula (B):

（B）

wherein PFPE is a perfluoropolyether group;

(4) adding an intermediate product III into a reactor under the atmosphere of protective gas, dropwise adding a Grignard reagent II solution at 0-10 ℃, stirring at room temperature, reacting to obtain a mixed solution d after the reaction is finished, and performing post-treatment on the mixed solution d to obtain an intermediate product IV, wherein the structural formula of the intermediate product IV is shown as the formula (C):

（C）

wherein PFPE is a perfluoropolyether group;

the Grignard reagent II is allyl magnesium bromide or allyl magnesium chloride;

(5) adding an intermediate product IV and a catalyst into a reactor in a protective gas atmosphere, dropwise adding trichlorosilane at 90-120 ℃, stirring and reacting to obtain a mixed solution e after the reaction is finished, and performing post-treatment on the mixed solution e to obtain an intermediate product V, wherein the structural formula of the intermediate product V is shown as a formula (D):

（D）

wherein PFPE is a perfluoropolyether group;

(6) adding an intermediate product V into a reactor under a protective gas atmosphere, dripping an organic alkali solution at the temperature of 80-100 ℃, stirring and reacting to obtain a mixed solution f after the reaction is finished, and performing post-treatment on the mixed solution f to obtain a perfluoropolyether siloxane compound, wherein the structural formula of the perfluoropolyether siloxane compound is shown as the formula (E):

（E）

wherein PFPE is a perfluoropolyether group, R is-OCH₃or-OCH₂CH₃。

Preferably, the catalyst in step (1) is cuprous chloride; the organic base is one of triethylamine and tri-n-propylamine; the molar ratio of the Grignard reagent I to the catalyst to the organic base is 1 to (1-1.3); the molar ratio of the Grignard reagent I to the trichlorosilane is 1: 1-1.5.

More preferably, in the step (1), the grignard reagent I is allyl bromide, the molar ratio of the grignard reagent I to the organic base is 1: 1.2-1.3, and the molar ratio of the grignard reagent I to the trichlorosilane is 1: 1.3.

More preferably, the reaction temperature in step (1) is room temperature.

Preferably, the molar ratio of the intermediate product I to the perfluoropolyether alcohol in the step (2) is 1: 3-3.6; the organic base is potassium tert-butoxide, and the nucleophilic reagent is tert-butanol; the molar ratio of the potassium tert-butoxide to the perfluoropolyether alcohol is (1-1.3) to 1; taking the mass sum of the intermediate product I, the perfluoropolyether alcohol and the potassium tert-butoxide as the total mass, wherein the addition amount of the tert-butanol is calculated by adding not less than 1mL of tert-butanol in every 0.5g of the total mass.

More preferably, the molecular weight of the perfluoropolyether alcohol in step (2) is 1000 to 2000.

More preferably, the perfluoropolyether alcohol of step (2) has the formula (F):

（F）

wherein n is an integer of 6 to 12.

More preferably, the molar ratio of the potassium tert-butoxide to the perfluoropolyether alcohol is (1.2-1.3) to 1

Preferably, the catalyst in step (3) is an isopropanol solution of chloroplatinic acid; the molar ratio of the intermediate product II to the chloroplatinic acid is (10000-30000) to 1; the molar ratio of the intermediate product II to the trichlorosilane is 1: 1-1.3.

More preferably, the concentration of the isopropanol solution of chloroplatinic acid is 0.05 mol/L.

More preferably, the molar ratio of the intermediate product II to the chloroplatinic acid in the step (3) is (15000-30000): 1.

Preferably, the molar ratio of the intermediate product III to the Grignard reagent II in the step (4) is 1: 3-3.5.

More preferably, the grignard reagent ii solution in the step (4) is prepared by dissolving grignard reagent ii in tetrahydrofuran; the Grignard reagent II is allyl magnesium bromide, and the concentration of the solution of the Grignard reagent II is 1 mol/L.

More preferably, after the temperature is reduced to 0 ℃ in the step (4), the Grignard reagent II solution is added dropwise.

More preferably, the reaction temperature in step (4) is room temperature.

Preferably, the catalyst in step (5) is an isopropanol solution of chloroplatinic acid; the molar ratio of the intermediate product IV to trichlorosilane is 1: 3-4.5.

More preferably, the molar ratio of the intermediate product IV to the chloroplatinic acid in the step (5) is (10000-30000): 1.

More preferably, the concentration of the isopropanol solution of chloroplatinic acid is 0.05 mol/L; the molar ratio of the intermediate product IV to the chloroplatinic acid is (10000-15000) to 1.

Preferably, the organic base in the step (6) is one of triethylamine and pyridine; the organic alkali solution is prepared by dissolving organic alkali in methanol or ethanol; the molar ratio of the intermediate product V to the organic alkali is 1: 9-11.7.

More preferably, the organic base in step (6) is triethylamine, and the organic base solution is prepared by dissolving an organic base in methanol.

More preferably, the amount of methanol added is 20 times or more the amount of the organic base substance.

More preferably, the final product is a methoxy-modified perfluoropolyether siloxane compound.

More preferably, the post-treatment process in step (1) includes the following specific steps: filtering the mixed solution a, collecting filtrate, adding an extractant tetrahydrofuran into the filtrate, fully extracting, standing, collecting a non-extractant layer, and removing the residual extractant by reduced pressure evaporation;

the post-treatment process in the step (2) comprises the following specific steps: filtering the mixed solution b, collecting filtrate, standing the filtrate, collecting a lower organic phase, adding an extractant methanol into the lower organic phase, fully extracting, standing, collecting a non-extractant layer, and removing residual extractant by reduced pressure evaporation;

the post-treatment process in the step (3) comprises the following specific steps: standing the mixed solution c, collecting a lower organic phase, adding tetrahydrofuran serving as an extractant into the lower organic phase, fully extracting, standing, collecting a non-extractant layer, and evaporating under reduced pressure to remove the residual extractant;

the post-treatment process in the step (4) comprises the following specific steps: adding a large amount of methanol into the mixed solution d to quench the unreacted Grignard reagent II, filtering, collecting filtrate, standing and layering the filtrate, collecting a lower organic phase, adding an extractant methanol into the lower organic phase, fully extracting, standing, collecting a non-extractant layer, and removing the residual extractant by reduced pressure evaporation;

the post-treatment process in the step (5) comprises the following specific steps: standing the mixed solution e, collecting a lower organic phase, adding tetrahydrofuran serving as an extractant into the lower organic phase, fully extracting, standing, collecting a non-extractant layer, and evaporating under reduced pressure to remove the residual extractant;

the post-treatment process in the step (6) comprises the following specific steps: and standing the mixed solution f, collecting a lower organic phase, adding an extractant methanol into the lower organic phase, fully extracting, standing, collecting a non-extractant layer, and evaporating under reduced pressure to remove the residual extractant.

More preferably, the protective gas is nitrogen.

In a second aspect, the present invention provides a perfluoropolyether siloxane product prepared by the process provided in the first aspect.

The third aspect of the invention provides the application of the perfluoropolyether siloxane product described in the second aspect in the super-hydrophobic anti-fingerprint coating, in particular to the industries of semiconductors, mobile phone 3C, tempered glass, automobile glass, clocks and the like, and is preferably a coating product on the surface of a semiconductor silicon wafer.

The fourth aspect of the invention provides a preparation method of a super-hydrophobic anti-fingerprint coating, which comprises the following steps: diluting the perfluoropolyether siloxane product to 0.2-0.5 wt% by using a diluent to obtain a diluted solution, then adding a surface treating agent into the diluted solution, uniformly stirring, finally adjusting the pH of the solution to 3.5-5 by using an organic acid to obtain the super-hydrophobic anti-fingerprint coating, coating the coating on a base material, and curing at the temperature of 110-150 ℃ to form a film to obtain the super-hydrophobic anti-fingerprint coating;

the perfluoropolyether siloxane product is the perfluoropolyether siloxane product of the second aspect described above; the molar ratio of the perfluoropolyether siloxane product to the surface treating agent is 1: 1-1.3; the surface treating agent is a mixture of an intermediate product I and isopropyl acetate, and the molar ratio of the intermediate product I to the isopropyl acetate is 1: 1-2;

the diluent is hydrofluoroether and trifluorotrichloroethane, and the hydrofluoroether is HFE-7100 or HFE-7200.

More preferably, the diluent dilution process is specifically: diluting the perfluoropolyether siloxane product to 20% at most by using trifluorotrichloroethane, and then diluting the perfluoropolyether siloxane product to 0.2-0.5 wt% by using perfluorobutyl methyl ether; or diluting the perfluoropolyether siloxane product to 0.2-0.5 wt% by using a composite solution of hydrofluoroether and trifluorotrichloroethane in a certain ratio.

More preferably, the molar ratio of the perfluoropolyether siloxane product to surface treatment is 1: 1; the molar ratio of the intermediate product I to the isopropyl acetate is 1: 1.

More preferably, the organic acid is acetic acid.

Compared with the prior art, the invention has the following beneficial effects:

(1) the method adopts a low-cost and simple synthetic route to prepare the perfluoropolyether structure with the three branched chains to obtain the dendritic polyether siloxane with the polyfunctional group structure. The synthetic route replaces high-cost and difficult-to-synthesize high-polymer perfluoropolyether with the oligomeric perfluoropolyether, reduces the synthetic difficulty of the whole coating, greatly reduces the production cost of the perfluoropolyether siloxane coating, and can show more excellent performances such as oil stain resistance, scratch resistance, durability and the like on the basis of reducing the production cost of the perfluoropolyether siloxane coating product, thereby having practical value. In one embodiment, when the perfluoropolyether siloxane product is prepared, the yield of the intermediate products I-IV is more than 95%, and the fingerprint-proof coating prepared from the perfluoropolyether siloxane product prepared by the method has a water contact angle of more than 120 degrees compared with a similar fingerprint-proof coating product (the water contact angle is kept at about 107 degrees) prepared from perfluoropolyether with the same molecular weight, so that the perfluoropolyether siloxane product has excellent hydrophobicity. The reason is that in the curing process of preparing the super-hydrophobic fingerprint-resistant coating, the multi-chain-end perfluoropolyether structure prepared by the invention migrates and aggregates to the surface of the coating under the action of surface energy, so that the formed coating has excellent hydrophobic and oleophobic properties and excellent antifouling properties.

(2) The super-hydrophobic anti-fingerprint coating prepared by the invention has better hydrophobic effect than the existing anti-fingerprint coating, and the formed cured coating has excellent adhesion with the base material. In one embodiment, before and after the super-hydrophobic anti-fingerprint coating prepared by the invention is subjected to a friction resistance test, the angle change of the water drop angle formed by water drops on the anti-fingerprint coating is not large (2-4 degrees), and is smaller than the angle change degree (4-5 degrees) of the water drop angle of a similar anti-fingerprint coating, so that the anti-fingerprint coating prepared by the invention and a mobile phone touch screen glass sample are fully proved to have good bonding force. The reason is that the molecular chain of the perfluoropolyether siloxane product prepared by the invention has more hydrolysis groups, so that a plurality of chemical bonds can be conveniently formed with the surface of the substrate, the wear resistance can be greatly improved, and the service life can be greatly prolonged. The molecular chain bonds can form a cross-linking structure after hydrolysis, the hardness of the cured coating is increased, the service life of the coating is prolonged, the base material can be effectively protected, and the coating has the characteristics of friction resistance, excellent durability and the like. Therefore, the super-hydrophobic anti-fingerprint coating prepared by the invention can be applied to industries such as mobile phone touch screens, high-end digital products, semiconductors and the like, and is particularly suitable for the surfaces of touch screens and semiconductor silicon wafers.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail by the following examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail with reference to examples.

Preparation of perfluoropolyether siloxane compound

Examples 1 to 4

The embodiment of the invention provides a preparation method of a perfluoropolyether siloxane compound, which comprises the following steps:

(1) in N₂Under the protection condition, adding 20g of allyl bromide, 16.3-20.7 g of cuprous chloride and 20-31 g of organic alkali into a reactor, dropwise adding 29g of trichlorosilane at room temperature, and reacting and refluxing for 6 hours until the system is in a non-reflux state; and after the reaction is finished, filtering to remove insoluble substances, extracting unreacted trichlorosilane and organic alkali by using tetrahydrofuran serving as an extracting agent, collecting a non-extracting agent layer, and distilling under reduced pressure to remove residual tetrahydrofuran to obtain an intermediate product I (allyl trichlorosilane).

(2) In N₂Under the protection condition, adding 50g of perfluoropolyether alcohol (molecular weight is 1000-2000), 1.3-2.9 g of intermediate product I, 3.6-6.7 g of potassium tert-butoxide and 110mL of tert-butyl alcohol into a reactor, and heating for 36h at 70 ℃ to react; after the reaction is finished, filtering to remove insoluble substances, standing for layering and collecting a lower organic phase, extracting the lower organic phase with methanol, collecting a non-extractant layer, repeatedly extracting for 3 times, and removing residual methanol by reduced pressure evaporation to obtain an intermediate product II, wherein the intermediate product II has the following structural formula:

wherein PFPE is (CF)₃CF₂CF₂O)_nCF(CF₃) And n is an integer of 6 to 12.

The perfluoropolyether alcohol has the following structural formula:

wherein n is an integer of 6 to 12.

(3) In N₂Under the protection condition, 50g of intermediate product II and 0.01mL of chloroplatinic acid-isopropanol solution (0.05 mol/L) are added into a reactor, and 1.45-2.8 g of trichlorosilane is slowly dripped at 100 DEG CAfter the dropping, the mixture is stirred for 4 hours to react; after the reaction is finished, extracting unreacted trichlorosilane and catalyst in the lower organic phase by using an extracting agent tetrahydrofuran, collecting a non-extracting agent layer, and removing residual tetrahydrofuran by reduced pressure evaporation to obtain an intermediate product III, wherein the structural formula of the intermediate product III is as follows:

wherein PFPE is (CF)₃CF₂CF₂O)_nCF(CF₃) And n is an integer of 6 to 12.

(4) In N₂Under the protection condition, adding 50g of the intermediate product III into a reactor, slowly dropwise adding 26-56 mL of 1 mol/L allyl magnesium bromide tetrahydrofuran solution (containing 3.8-8.1 g of allyl magnesium bromide) at 0 ℃, and after dropwise adding, heating to room temperature and continuously stirring for 24 hours to carry out reaction; adding a large amount of methanol to quench unreacted allyl magnesium bromide after the reaction is finished, filtering and collecting filtrate, standing and separating the filtrate, collecting a lower organic phase, adding an extractant methanol into a lower organic phase, fully extracting and standing, collecting a non-extractant layer, repeatedly extracting for 3 times, and removing residual methanol by reduced pressure evaporation to obtain an intermediate product IV, wherein the structural formula of the intermediate product IV is as follows:

wherein PFPE is (CF)₃CF₂CF₂O)_nCF(CF₃) And n is an integer of 6 to 12.

(5) In N₂Under the protection condition, adding 50g of intermediate product IV and 0.015-0.02 mL of chloroplatinic acid-isopropanol solution (0.05 mol/L) into a reactor, then slowly dropwise adding 4.8-9.4 g of trichlorosilane at 100 ℃, and stirring for reaction after dropwise adding; after the reaction is finished, extracting the unreacted trichlorosilane and the catalyst in the lower organic phase by using an extracting agent tetrahydrofuran, collecting the non-extracting agent layer, and removing the residue by reduced pressure evaporationTetrahydrofuran to obtain an intermediate product V, wherein the structural formula of the intermediate product V is shown as follows:

wherein PFPE is (CF)₃CF₂CF₂O)_nCF(CF₃) And n is an integer of 6 to 12.

(6) In N₂Under the protection condition, adding 50g of the intermediate product V into a reactor, slowly dropwise adding 30mL of methanol solution containing triethylamine (8.9-15.1 g) at 100 ℃, and after dropwise adding, carrying out reflux stirring for reaction for 4 hours until no white smoke is generated and then stirring for 2 hours; standing and separating liquid after the reaction is finished, collecting a lower organic phase, adding an extractant methanol into the lower organic phase, standing after full extraction, collecting a non-extractant layer, repeatedly extracting for 3 times, and removing residual methanol by reduced pressure evaporation to obtain a final product, wherein the structural formula of the final product is as follows:

wherein PFPE is (CF)₃CF₂CF₂O)_nCF(CF₃) And n is an integer of 6 to 12.

Examples 1 to 4 differ in the process parameters of the respective steps, as shown in table 1.

TABLE 1 values of the Process parameters in examples 1 to 4

Example 5

A perfluoropolyether siloxane compound was prepared in substantially the same manner as in example 1, except that: the reaction temperature in the step (2) is 50 ℃; the reaction temperature in the step (3) is 90 ℃; the reaction temperature in the step (5) is 90 ℃; the reaction temperature in step (6) was 80 ℃.

Example 6

A perfluoropolyether siloxane compound was prepared in substantially the same manner as in example 1, except that: the reaction temperature in the step (2) is 60 ℃; the reaction temperature in the step (3) is 120 ℃; the reaction temperature in the step (5) is 120 ℃; the reaction temperature in step (6) was 90 ℃.

Preparation of super-hydrophobic anti-fingerprint coating

Example 7

The embodiment of the invention provides a preparation method of a super-hydrophobic anti-fingerprint coating, which comprises the following steps:

(a) diluting the prepared perfluoropolyether siloxane to 20% by using trifluorotrichloroethane, then diluting to 0.5% by using perfluorobutyl methyl ether (HFE-7100), adding a surface treatment agent allyl trichlorosilane and isopropyl acetate in amounts of the prepared perfluoropolyether siloxane and the like, and finally adding acetic acid to adjust the pH value of the solution to 3.5-5 to obtain the coating solution.

(b) Ultrasonically cleaning a mobile phone touch screen with acetone for 30 min at room temperature, ultrasonically cleaning with absolute ethyl alcohol for 30 min, and air-drying for later use.

(c) And spraying the coating solution on a pretreated mobile phone touch screen, standing for 10 min at room temperature, heating and baking for 1 h at 110 ℃, and curing to form a film to obtain the super-hydrophobic anti-fingerprint coating.

Wherein the perfluoropolyether siloxane is the perfluoropolyether siloxane product prepared in example 1.

Example 8

The content of a preparation method of the super-hydrophobic fingerprint-resistant coating is basically the same as that of the example 7, and the difference is that: the perfluoropolyether siloxane is the perfluoropolyether siloxane product prepared in example 2.

Example 9

The content of a preparation method of the super-hydrophobic fingerprint-resistant coating is basically the same as that of the example 7, and the difference is that: the perfluoropolyether siloxane is the perfluoropolyether siloxane product prepared in example 3.

Example 10

The content of a preparation method of the super-hydrophobic fingerprint-resistant coating is basically the same as that of the example 7, and the difference is that: the perfluoropolyether siloxane is the perfluoropolyether siloxane product prepared in example 4.

Example 11

The content of a preparation method of the super-hydrophobic fingerprint-resistant coating is basically the same as that of the example 7, and the difference is that: diluting with perfluorobutyl methyl ether to 0.2 wt% in step (a);

comparative example 1

The content of a preparation method of the anti-fingerprint coating is basically the same as that of the example 7, except that: the perfluoropolyether siloxane is a perfluoropolyether siloxane compound (D1), and the structural formula of the perfluoropolyether siloxane compound (D1) is shown as follows:

PFPE-CH₂O-CH₂-CH₂-CH₂-Si（OCH₃）₃

the preparation method of D1 specifically comprises the following steps: hydroxyl-terminated perfluoropolyether (molecular weight is 3000) is used as a starting material, and reacts with bromopropylene or chloropropene to prepare allyl perfluoropolyether, and then the trimethoxy silane with the perfluoropolyether structure is prepared through hydrosilylation.

Comparative example 2

The content of a preparation method of the anti-fingerprint coating is basically the same as that of the example 7, except that: the perfluoropolyether siloxane is a perfluoropolyether siloxane compound (D2), and the structural formula of the perfluoropolyether siloxane compound (D2) is shown as follows:

the preparation method of D2 specifically comprises the following steps: methyl-terminated esterified perfluoropolyether (molecular weight is 3000) is used as an initial raw material to synthesize perfluoropolyether siloxane with amido bond as a spacer with 3-aminopropyl trimethoxy silane.

Comparative example 3

The content of a preparation method of the anti-fingerprint coating is basically the same as that of the example 7, except that: the perfluoropolyether siloxane is a perfluoropolyether siloxane compound (D3) which is a commercially available product, namely bis-terminal silicon ethoxy perfluoropolyether (molecular weight 2000), and the structural formula of the perfluoropolyether siloxane compound (D3) is shown as follows:

and (3) performance testing:

in order to investigate the hydrophobic and oleophobic properties, stain resistance and rub resistance of the superhydrophobic fingerprint-resistant coating prepared by the present invention, the inventors performed the following experiments, i.e., example 7, example 8, example 9, example 10, comparative example 1, comparative example 2 and comparative example 3, respectively, and then performed the contact angle test, the stain resistance test and the rub resistance test on the obtained fingerprint-resistant coating, respectively. The results are shown in Table 2. The specific steps of the test procedure are as follows:

1. contact Angle testing

The contact angle test adopts a liquid drop method, and the hydrophobic and oleophobic properties of the anti-fingerprint coating are represented by the contact angle of deionized water and the contact angle of n-hexadecane on the surface of the glass. Test contact angles of water and n-hexadecane were measured using a water contact angle tester JGW-360a and were measured at room temperature. And (3) flatly paving the mobile phone touch screen glass sample to be detected on a horizontal platform of the contact angle tester and fixing, wherein the size of the liquid drop is 8 microliter, measuring five points of the same sample, and taking the average value of the five points. The larger the contact angle, the smaller the surface energy.

2. Antifouling Property test

Testing with an oil pen: a commercially available oil-based ink pen was used to draw blue lines on the cured film surface of the cell phone glass screen. The blue ink was evaluated for its resistance to staining according to its shrinkage. The criteria are as follows:

c-do not shrink, line;

b-shrink to dotted line;

a-shrinkage to point.

Fingerprint testing: and (3) sticking fingerprints on the coating, and repeatedly wiping the surface of the cured film for 5 times by using Kim Wipes dust-free cloth to form the fingerprint removal condition. The ease of fingerprint removal was evaluated visually.

C, obviously leaving stains after wiping;

b, removing most stains and having micro-marks after wiping;

and A, removing all stains after wiping.

3. Rub resistance test

And (3) loading 1kg of pressure by using steel wool (BONSTAR #0000, 20 mm diameter), horizontally rubbing the steel wool on the coating sample plate repeatedly for 8000 times, wherein the rubbing distance is 20-40 mm, the frequency is 3600-6000 times/min, and testing the water contact angle according to the contact angle testing method.

TABLE 2 anti-fingerprint Performance test results for the superhydrophobic anti-fingerprint coating prepared in the present invention

As can be seen from table 2, before and after the anti-rubbing test, the angle change of the water drop angle formed by the water drops on the anti-fingerprint coating is not large, so that the anti-fingerprint coating and the mobile phone touch screen glass sample have good bonding force, and have good anti-fingerprint property and anti-rubbing property. Compared with the similar anti-fingerprint coating, the hydrophobic property and the abrasion resistance are obviously improved. Meanwhile, the super-hydrophobic fingerprint-resistant coating prepared by the invention uses low molecular weight perfluoropolyether alcohol in the synthesis process, so that the super-hydrophobic fingerprint-resistant coating can show more excellent performances such as oil stain resistance, scratch resistance and durability on the basis of reducing the production cost of a perfluoropolyether siloxane coating product, and has excellent hand feeling, thereby having practical value. The anti-fingerprint coating can be applied to the industries of semiconductors, mobile phone 3C industry, toughened glass, automobile glass, clocks and watches and the like, in particular to the surface of a semiconductor silicon wafer.

In conclusion, the present invention effectively overcomes the disadvantages of the prior art and has high industrial utilization value. The above-described embodiments are intended to illustrate the substance of the present invention, but are not intended to limit the scope of the present invention. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the invention.