Anti-discoloration and anti-fingerprint coating based on siloxane perfluoropolyether and preparation method thereof

Abstract

The invention provides a siloxane-based perfluoropolyether anti-discoloration and anti-fingerprint coating and a preparation method thereof. The method comprises the following steps: adding a metal cyanide catalyst into a reaction kettle; adding perfluoroalkylene oxide and perfluoroether glycol into the reaction kettle under the condition of nitrogen, and reacting for a first time at a first temperature to obtain a perfluoropolyether intermediate; and adding a phase transfer catalyst and (3-chloropropyl) triethoxysilane into the perfluoropolyether intermediate under an alkaline condition, reacting for a second time at a second temperature to obtain siloxane perfluoropolyether, and preparing the anti-discoloration anti-fingerprint discoloration coating through the siloxane perfluoropolyether. The siloxane perfluoropolyether is prepared through a preset scheme, the cost is low, the yield is high, separation treatment is easy, and the anti-discoloration and anti-fingerprint coating prepared from the siloxane perfluoropolyether has the advantages of being good in water resistance, oil resistance and friction resistance, capable of keeping the color of a membrane material and the like.

Description

Technical Field

[0001] The present application relates to the field of chemical technology, and in particular to a siloxane perfluoropolyether-based anti-discoloration and anti-fingerprint coating and a preparation method thereof. Background Art

[0002] With the advancement of science and technology and the development of materials science, the application of various new coating materials in electronic equipment, optical devices, household goods and automobiles has gradually increased. As a high-performance coating material, silicone perfluoropolyether (SPFPE) has attracted widespread attention due to its unique physical and chemical properties and excellent surface properties. Especially in anti-discoloration and anti-fingerprint coatings, silicone perfluoropolyethers show significant advantages. Silicone perfluoropolyether is a class of polymers with good temperature resistance, chemical resistance and excellent surface properties. Its molecular chain contains silicon oxygen bonds and perfluoroalkyl groups, which give it special hydrophobicity and stain resistance. This material can effectively resist the erosion of the surface by environmental factors such as dust, water stains, grease, etc. in many application scenarios. With the improvement of the quality of life, people have put forward higher requirements for the appearance and durability of consumer goods. Especially on the screen and body surfaces of electronic products such as smartphones and tablets, users generally expect higher stain resistance and scratch resistance. Traditional coating technology usually uses polyester, polyurethane, etc. as the main components, but there are certain limitations in durability and appearance retention. In order to meet the needs of consumers, researchers are constantly exploring new materials and technologies, among which silicone perfluoropolyether coatings came into being. Silicone perfluoropolyether anti-discoloration and anti-fingerprint coatings are mainly used in electronic products, automotive industry, household goods and other fields. In smartphones and laptops, silicone perfluoropolyether coatings are widely used on the surfaces of screens and shells, which improves the product's anti-fouling ability while reducing the adhesion of fingerprints and grease, ensuring the user's visual experience in daily use. With the increasing sophistication of automobile exterior design, silicone perfluoropolyether coatings are gradually used to protect the car body and interior, which can effectively prevent pollution and aging, and improve the gloss and beauty of the car. In the fields of kitchen utensils, bathroom products, etc., the application of silicone perfluoropolyether coatings significantly reduces the difficulty of cleaning, extends the service life, and maintains a good appearance.

[0003] Currently, most commercial products have polysiloxane groups, which can prevent oil stains while improving adhesion and friction resistance. However, the complex synthesis steps, difficult separation, and high costs are not conducive to the large-scale production and commercial promotion of the product. At the same time, the product performance needs to be further improved. Summary of the invention

[0004] In view of the above problems, the present application is proposed to provide a silicone perfluoropolyether-based anti-discoloration and anti-fingerprint coating and a preparation method thereof that overcomes the above problems or at least partially solves the above problems, comprising:

[0005] A method for preparing a discoloration and fingerprint-proof coating based on siloxane perfluoropolyether, comprising the steps of:

[0006] adding a metal cyanide catalyst into a reaction kettle;

[0007] Under nitrogen conditions, adding perfluoroalkylene oxide and perfluoroether diol to the reaction kettle, reacting at a first temperature for a first time to obtain a perfluoropolyether intermediate;

[0008] Under alkaline conditions, a phase transfer catalyst and (3-chloropropyl)triethoxysilane are added to the perfluoropolyether intermediate, and the reaction is carried out at a second temperature for a second time to obtain a siloxane perfluoropolyether; wherein the general structural formula of the siloxane perfluoropolyether is:

[0009]

[0010] In the general formula, R1 is C1~C 10 Perfluorinated straight chain alkanes or C1~C 10 Perfluorinated branched alkanes;

[0011] R2 is a perfluoroether alkyl group;

[0012] The anti-discoloration and anti-fingerprint discoloration coating is prepared by using the silicone perfluoropolyether.

[0013] Furthermore, in the step of adding a metal cyanide catalyst into the reaction kettle, the metal cyanide catalyst is a mixture of at least one double metal cyanide compound and at least one rare earth compound.

[0014] Further, the step of adding perfluoroalkylene oxide and perfluoroether diol to the reactor under nitrogen conditions and reacting at a first temperature for a first time to obtain a perfluoropolyether intermediate comprises:

[0015] The reactor was evacuated and replaced with nitrogen three times;

[0016] Adding perfluoroalkylene oxide and perfluoroether diol into the reaction kettle; wherein the molar ratio of the perfluoroalkylene oxide to the perfluoroether diol is 50-100:1;

[0017] The reaction is carried out at a first temperature and for a first time to obtain a perfluoropolyether intermediate; wherein the general structural formula of the perfluoropolyether intermediate is:

[0018]

[0019] Furthermore, the step of reacting at a first temperature for a first time to obtain a perfluoropolyether intermediate comprises:

[0020] At a first temperature, adding the perfluorooxypropane into a reaction kettle in batches, reacting for a first time to obtain a reaction product;

[0021] The reaction product is filtered and washed with methanol to obtain a perfluoropolyether intermediate.

[0022] Furthermore, the general structural formula of the perfluoroalkylene oxide is:

[0023]

[0024] The general structural formula of the perfluoroether diol is:

[0025] HO——R2OH 。

[0026] Furthermore, the step of adding a phase transfer catalyst and (3-chloropropyl)triethoxysilane to the perfluoropolyether intermediate under alkaline conditions and reacting at a second temperature for a second time to obtain a siloxane perfluoropolyether comprises:

[0027] Under a nitrogen environment, the perfluoropolyether intermediate, the phase transfer catalyst and the alkali solution are stirred and mixed uniformly; wherein the alkali solution is a sodium hydroxide solution, a potassium hydroxide solution or a sodium hydride solution;

[0028] Slowly adding (3-chloropropyl)triethoxysilane, reacting at a second temperature for a second time to obtain a reaction mixture;

[0029] The reaction mixture was filtered, washed with methanol, and evaporated to dryness to obtain siloxane perfluoropolyether.

[0030] Further, the molar ratio of the perfluoropolyether intermediate to the (3-chloropropyl)triethoxysilane is 3-6:1;

[0031] The molar ratio of the alkali solution to the perfluoropolyether intermediate is 3-6:1;

[0032] The molar ratio of the phase transfer catalyst to the perfluoropolyether intermediate is 0.1-0.2:1.

[0033] Furthermore, the first temperature is 100-150° C., and the first time duration is 5-10 hours.

[0034] Furthermore, the second temperature is 30-80° C., and the second time period is 12-24 hours.

[0035] A discoloration and anti-fingerprint coating based on siloxane perfluoropolyether, wherein the coating is prepared by any of the preparation methods described above, and the general structural formula of the siloxane perfluoropolyether is:

[0036]

[0037] This application has the following advantages:

[0038] In the embodiments of the present application, in view of the shortcomings of the prior art that perfluoropolyether is too expensive and has limited performance, the present application provides a method for preparing an anti-discoloration and anti-fingerprint coating based on siloxane perfluoropolyether, comprising the steps of: adding a metal cyanide catalyst to a reactor; adding perfluoroalkylene oxide and perfluoroether diol to the reactor under nitrogen conditions, reacting at a first temperature for a first time to obtain a perfluoropolyether intermediate; adding a phase transfer catalyst and (3-chloropropyl) triethoxysilane to the perfluoropolyether intermediate under alkaline conditions, reacting at a second temperature for a second time to obtain a siloxane perfluoropolyether, and preparing an anti-discoloration and anti-fingerprint coating by using the siloxane perfluoropolyether. The siloxane perfluoropolyether is prepared by a preset scheme, with low cost and high yield, and is simple and easy to separate and process. The anti-discoloration and anti-fingerprint coating prepared with siloxane perfluoropolyether has good water resistance, oil resistance, friction resistance, and film color retention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the description of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0040] Figure 1 This is a flow chart of the steps of a method for preparing a silicone perfluoropolyether anti-discoloration and anti-fingerprint coating provided in one embodiment of the present application. DETAILED DESCRIPTION

[0041] In order to make the objects, features and advantages of the present application more obvious and understandable, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0042] The inventors have found through analysis of the prior art that the perfluoropolyether coating prepared by the prior art has a complicated preparation process and is difficult to separate, resulting in a high preparation cost and difficulty in application.

[0043] Reference Figure 1 , shows a flow chart of the steps of a method for preparing a discoloration and anti-fingerprint coating based on siloxane perfluoropolyether provided in an embodiment of the present application, the method comprising the steps of:

[0044] S110, adding a metal cyanide catalyst into the reaction kettle;

[0045] S120, adding perfluoroalkylene oxide and perfluoroether diol to the reaction kettle under nitrogen conditions, reacting at a first temperature for a first time to obtain a perfluoropolyether intermediate;

[0046] S130, under alkaline conditions, adding a phase transfer catalyst and (3-chloropropyl)triethoxysilane to the perfluoropolyether intermediate, reacting at a second temperature for a second time to obtain a siloxane perfluoropolyether; wherein the general structural formula of the siloxane perfluoropolyether is:

[0047]

[0048] In the general formula, R1 is C1~C 10 Perfluorinated straight chain alkanes or C1~C 10 Perfluorinated branched alkanes;

[0049] R2 is a perfluoroether alkyl group;

[0050] S140, preparing an anti-discoloration and anti-fingerprint discoloration coating by using the silicone perfluoropolyether.

[0051] In the embodiments of the present application, in view of the shortcomings of the prior art that perfluoropolyether is too expensive and has limited performance, the present application provides a method for preparing an anti-discoloration and anti-fingerprint coating based on siloxane perfluoropolyether, comprising the steps of: adding a metal cyanide catalyst to a reactor; adding perfluoroalkylene oxide and perfluoroether diol to the reactor under nitrogen conditions, reacting at a first temperature for a first time to obtain a perfluoropolyether intermediate; adding a phase transfer catalyst and (3-chloropropyl) triethoxysilane to the perfluoropolyether intermediate under alkaline conditions, reacting at a second temperature for a second time to obtain a siloxane perfluoropolyether, and preparing an anti-discoloration and anti-fingerprint coating by using the siloxane perfluoropolyether. The siloxane perfluoropolyether is prepared by a preset scheme, with low cost and high yield, and is simple and easy to separate and process. The anti-discoloration and anti-fingerprint coating prepared with siloxane perfluoropolyether has good water resistance, oil resistance, friction resistance, and film color retention.

[0052] Next, a preparation method of a silicone perfluoropolyether-based anti-discoloration and anti-fingerprint coating in this exemplary embodiment will be further described.

[0053] As described in step S110, a metal cyanide catalyst is added into the reaction kettle.

[0054] In one embodiment of the present application, the metal cyanide catalyst is a mixture of at least one double metal cyanide compound and at least one rare earth compound. The amount of the metal cyanide catalyst added is 50-100 ppm based on the weight of the product.

[0055] As an example, the at least one double metal cyanide compound and the at least one rare earth compound may be Co[Fe(CN)3]3·2ZnCl2·3LaCl3 and Ni[Fe(CN)3]2·5ZnCl2·2CeCl3, etc.

[0056] As described in step S120, under nitrogen conditions, perfluoroalkylene oxide and perfluoroether diol are added to the reaction kettle, and reacted at a first temperature for a first time to obtain a perfluoropolyether intermediate.

[0057] In one embodiment of the present invention, the specific process of step S120 of "adding perfluoroalkylene oxide and perfluoroether diol to the reactor under nitrogen conditions, reacting at a first temperature for a first time to obtain a perfluoropolyether intermediate" can be further explained in combination with the following description.

[0058] As described in the following steps, the reactor was evacuated and replaced with nitrogen three times;

[0059] As described in the following steps, perfluoroalkylene oxide and perfluoroether diol are added into the reaction kettle; wherein the molar ratio of the perfluoroalkylene oxide to the perfluoroether diol is 50-100:1;

[0060] As described in the following steps, the reaction is carried out at a first temperature for a first time to obtain a perfluoropolyether intermediate; wherein the general structural formula of the perfluoropolyether intermediate is:

[0061]

[0062] It should be noted that the reaction of perfluoroalkylene oxide and perfluoroether diol to generate a perfluoropolyether intermediate is carried out in steps and can be interrupted without continuous reaction, which is convenient for production test operation.

[0063] In one embodiment of the present application, the specific process of the step of "reacting at a first temperature for a first time as described in the following steps to obtain a perfluoropolyether intermediate" can be further explained in combination with the following description.

[0064] As described in the following steps, at a first temperature, the perfluorooxypropane is added into a reaction kettle in batches, reacted for a first time, and a reaction product is obtained;

[0065] As described in the following steps, the reaction product was filtered and washed with methanol to obtain a perfluoropolyether intermediate.

[0066] It should be noted that the reaction can be ensured to proceed fully by adding the reactants in batches, and the total amount of reactants added needs to meet the preset ratio. The reactants are added in batches, and the total reaction time is the first time. The product is subsequently cleaned and purified by methanol, and the perfluoropolyether intermediate can also be cleaned by other organic solvents.

[0067] In one embodiment of the present application, the general structural formula of the perfluoroalkylene oxide is:

[0068]

[0069] The general structural formula of the perfluoroether diol is:

[0070] HO——R2OH 。

[0071] As described in step S130, under alkaline conditions, a phase transfer catalyst and (3-chloropropyl)triethoxysilane are added to the perfluoropolyether intermediate, and the reaction is carried out at a second temperature for a second time to obtain a siloxane perfluoropolyether; wherein the general structural formula of the siloxane perfluoropolyether is:

[0072]

[0073] In the general formula, R1 is C1~C 10 Perfluorinated straight chain alkanes or C1~C 10 Perfluorinated branched alkanes;

[0074] R2 is a perfluoroether alkyl group.

[0075] It should be noted that the alkaline condition can be provided by alkaline solution, the phase transfer catalyst and the alkaline solution are mixed to obtain a solvent, and then reactants such as a perfluoropolyether intermediate are added to react to obtain a final product.

[0076] The R2 group is:

[0077]

[0078] Or other perfluoropolyethers.

[0079] In one embodiment of the present invention, the specific process of step S130 of "adding a phase transfer catalyst and (3-chloropropyl)triethoxysilane to the perfluoropolyether intermediate under alkaline conditions, reacting at a second temperature for a second time to obtain a siloxane perfluoropolyether" can be further explained in combination with the following description.

[0080] As described in the following steps, under a nitrogen environment, the perfluoropolyether intermediate, the phase transfer catalyst and the alkali solution are stirred and mixed uniformly; wherein the alkali solution is a sodium hydroxide solution, a potassium hydroxide solution or a sodium hydride solution;

[0081] As described in the following steps, (3-chloropropyl)triethoxysilane is slowly added and reacted at a second temperature for a second time to obtain a reaction mixture;

[0082] The reaction mixture was filtered, washed with methanol, and evaporated to dryness to obtain the siloxane perfluoropolyether as described in the following steps.

[0083] In one embodiment of the present application, the molar ratio of the perfluoropolyether intermediate to the (3-chloropropyl)triethoxysilane is 3-6:1;

[0084] The molar ratio of the alkali solution to the perfluoropolyether intermediate is 3-6:1;

[0085] The molar ratio of the phase transfer catalyst to the perfluoropolyether intermediate is 0.1-0.2:1.

[0086] In one embodiment of the present application, the first temperature is 100-150° C., and the first time length is 5-10 hours.

[0087] In one embodiment of the present application, the second temperature is 30-80° C., and the second time period is 12-24 hours.

[0088] Example 1: In one specific implementation, a siloxane perfluoropolyether is prepared;

[0089] The reaction route is:

[0090]

[0091] Wherein, R1 is -CF3; R2 is

[0092] Preparation steps:

[0093] Add 5 mg of multimetal cyanide catalyst Co[Fe(CN)3]3·2ZnCl2·3LaCl3 to a 500 ml glass reactor, evacuate for half an hour, replace with nitrogen three times, add 40 g of perfluoropropylene oxide and 0.9 g of 1H,1H,8H,8H-octafluoro-3,6-dioxa-1,8-octanediol to the glass reactor under nitrogen, stir for half an hour, heat to 100°C and react for 2 hours, add 10 g of perfluoropropylene oxide, continue to react for 3 hours, and stop the reaction. The reaction product is filtered and washed with methanol to obtain a perfluoropolyether intermediate.

[0094] Under nitrogen protection, 40 g of the perfluoropolyether intermediate prepared in the previous step, 15 g of potassium hydroxide and 1.5 g of dodecyltrimethylammonium chloride were added to a 500 ml glass reactor, and the mixture was stirred and mixed evenly. 65 g of (3-chloropropyl)triethoxysilane was slowly added thereto, and the mixture was heated to 50°C and reacted for 12 hours. After the reaction, the mixture was filtered, washed with methanol, and rotary evaporated to obtain siloxane perfluoropolyether.

[0095] Example 2: In one specific implementation, a siloxane perfluoropolyether is prepared;

[0096] The reaction route is:

[0097]

[0098] Among them, R1 is -CF2CF2CF3; R2 is

[0099] Preparation steps:

[0100] In a 500 ml glass reactor, add 5 mg of multi-metal cyanide catalyst Ni[Fe(CN)3]2·5ZnCl2·2CeCl3, evacuate for half an hour, replace with nitrogen three times, add 40 g of perfluoropentylene oxide and 2.8 g of 1H,1H,11H,11H-perfluoro-3,6,9-trioxyundecane-1,11-diol to the glass reactor under nitrogen, stir for half an hour, heat to 120°C for 3 hours, add 10 g of perfluoropentylene oxide, continue to react for 3 hours, and stop the reaction. The reaction product is filtered and washed with methanol to obtain a perfluoropolyether intermediate.

[0101] Under nitrogen protection, 40 g of the perfluoropolyether intermediate from the previous step, 6 g of sodium hydroxide and 2.2 g of tetradecyltrimethylammonium chloride were added to a 500 ml glass reactor, and the mixture was stirred and mixed evenly. 36 g of (3-chloropropyl)triethoxysilane was slowly added thereto, and the mixture was heated to 30°C and reacted for 24 hours. After the reaction, the mixture was filtered, washed with methanol, and rotary evaporated to obtain siloxane perfluoropolyether.

[0102] As described in step S140, the anti-discoloration and anti-fingerprint discoloration coating is prepared by using the silicone perfluoropolyether.

[0103] The prepared siloxane perfluoropolyether material is dissolved in hydrofluoroether to prepare a dilute solution (1% to 5% by volume), and then sprayed on the surface of the product film material to quickly solidify to form an anti-discoloration and anti-fingerprint coating.

[0104] This application uses a three-step reaction of polymerization, end-capping, and substitution to simply and efficiently design and synthesize a siloxane-based perfluoropolyether. The anti-discoloration and anti-fingerprint coating formed by the perfluoropolymer has ultra-high hydrophobicity, oleophobicity, and friction resistance, and after the spraying process is completed, it can form a film quickly without subsequent treatment such as heating. The coating can be applied to metal oxide film materials of different products, maintaining the color of the film material while improving the product feel and life.

[0105] In one embodiment of the present application, a discoloration and anti-fingerprint coating based on siloxane perfluoropolyether is also proposed, wherein the coating is prepared by any of the preparation methods described above, and the general structural formula of the siloxane perfluoropolyether is:

[0106]

[0107] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0108] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0109] The above is a detailed introduction to a silicone perfluoropolyether-based anti-discoloration and anti-fingerprint coating and a preparation method thereof provided in the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for a person skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for preparing a discoloration and anti-fingerprint coating based on siloxane perfluoropolyether, characterized in that: Includes steps: adding a metal cyanide catalyst into a reaction kettle; Under nitrogen conditions, adding perfluoroalkylene oxide and perfluoroether diol to the reaction kettle, reacting at a first temperature for a first time to obtain a perfluoropolyether intermediate; Under alkaline conditions, a phase transfer catalyst and (3-chloropropyl)triethoxysilane are added to the perfluoropolyether intermediate, and the reaction is carried out at a second temperature for a second time to obtain a siloxane perfluoropolyether; wherein the general structural formula of the siloxane perfluoropolyether is: In the general formula, R1 is C1~C 10 Perfluorinated straight chain alkanes or C1~C 10 Perfluorinated branched alkanes; R2 is a perfluoroether alkyl group; The anti-discoloration and anti-fingerprint discoloration coating is prepared by using the silicone perfluoropolyether.

2. The preparation method according to claim 1, characterized in that: In the step of adding a metal cyanide catalyst into the reaction kettle, the metal cyanide catalyst is a mixture of at least one double metal cyanide compound and at least one rare earth compound.

3. The preparation method according to claim 1, characterized in that: The step of adding perfluoroalkylene oxide and perfluoroether diol to the reactor under nitrogen conditions and reacting at a first temperature for a first time to obtain a perfluoropolyether intermediate comprises: The reactor was evacuated and replaced with nitrogen three times; Adding perfluoroalkylene oxide and perfluoroether diol into the reaction kettle; wherein the molar ratio of the perfluoroalkylene oxide to the perfluoroether diol is 50-100:1; The reaction is carried out at a first temperature and for a first time to obtain a perfluoropolyether intermediate; wherein the general structural formula of the perfluoropolyether intermediate is:

4. The preparation method according to claim 3, characterized in that: The step of reacting at a first temperature for a first time to obtain a perfluoropolyether intermediate comprises: At a first temperature, adding the perfluorooxypropane into a reaction kettle in batches, reacting for a first time to obtain a reaction product; The reaction product is filtered and washed with methanol to obtain a perfluoropolyether intermediate.

5. The preparation method according to claim 1, characterized in that: The general structural formula of the perfluoroalkylene oxide is: The general structural formula of the perfluoroether diol is: HO——R2-OH.

6. The preparation method according to claim 1, characterized in that: The step of adding a phase transfer catalyst and (3-chloropropyl)triethoxysilane to the perfluoropolyether intermediate under alkaline conditions and reacting at a second temperature for a second time to obtain a siloxane perfluoropolyether comprises: Under a nitrogen environment, the perfluoropolyether intermediate, the phase transfer catalyst and the alkali solution are stirred and mixed uniformly; wherein the alkali solution is a sodium hydroxide solution, a potassium hydroxide solution or a sodium hydride solution; Slowly adding (3-chloropropyl)triethoxysilane, reacting at a second temperature for a second time to obtain a reaction mixture; The reaction mixture was filtered, washed with methanol, and evaporated to dryness to obtain siloxane perfluoropolyether.

7. The preparation method according to claim 6, characterized in that: The molar ratio of the perfluoropolyether intermediate to the (3-chloropropyl)triethoxysilane is 3-6:1; The molar ratio of the alkali solution to the perfluoropolyether intermediate is 3-6:1; The molar ratio of the phase transfer catalyst to the perfluoropolyether intermediate is 0.1-0.2:

1.

8. The preparation method according to claim 1, characterized in that: The first temperature is 100-150° C., and the first time period is 5-10 hours.

9. The preparation method according to claim 1, characterized in that: The second temperature is 30-80° C., and the second time period is 12-24 hours.

10. A discoloration and anti-fingerprint coating based on siloxane perfluoropolyether, characterized in that: The coating is prepared by the preparation method according to any one of claims 1 to 9, and the general structural formula of the siloxane perfluoropolyether is:

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