A UV-resistant perfluoropolyether siloxane and its preparation method and application

Abstract

The present invention discloses a UV-resistant perfluoropolyether siloxane, its preparation method, and application. The chemical structure of the perfluoropolyether siloxane is shown in Formula I, where m and n are each independently an integer greater than or equal to 1. By introducing two functional groups, a small molecule UV absorber and an aminosiloxane, into a bishydroxy perfluoropolyether, the present invention significantly improves the UV resistance and abrasion resistance of the coating, imparting an excellent hydrophobic and antifouling effect. Furthermore, the presence of multiple silicon-oxygen bonds effectively enhances the coating's adhesion and improves its durability. #imgabs0# Formula I

Description

Technical Field

[0001] The invention belongs to the technical field of UV-resistant coatings, and particularly relates to a UV-resistant perfluoropolyether siloxane and a preparation method and application thereof. Background Art

[0002] With the rapid development of the domestic automotive industry, electronic and intelligent auto parts have become a hot topic in the industry. Among them, electronic rearview mirrors and touch screens can provide people with a more comfortable and practical driving experience.

[0003] Currently, many AF (perfluorinated amorphous fluororesin) products on the market offer a superior water-repellent and oleophobic coating, making it impervious to scratching and effectively improving the user experience. However, over time, the coating is inevitably damaged by UV rays, leading to cracking and yellowing, which in turn weakens or even eliminates its anti-fingerprint and anti-scratch properties. Therefore, the development of a UV-resistant AF product specifically for automotive applications is necessary.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention

[0005] The purpose of the present invention is to provide a UV-resistant perfluoropolyether siloxane and its preparation method and application, which solves the problem that the coating of existing AF products is inevitably damaged by ultraviolet rays, can significantly improve the UV resistance and wear resistance of the coating, and has excellent hydrophobic and antifouling effects and coating adhesion.

[0006] In order to achieve the above object, the present invention provides a UV-resistant perfluoropolyether siloxane, the chemical structure of which is shown in Formula I:

[0007] Formula I

[0008] In formula I, m and n are integers greater than or equal to 1;

[0009] R1 is selected from 、 、 、 or ;

[0010] R2 is selected from 、 、 、 、 、 or ;

[0011] R3 is selected from 、 、 、 、 or ;

[0012] * in each substituent group indicates a bonding position.

[0013] By introducing two distinct functional groups, a small molecule UV absorber and an aminosiloxane, into the bishydroxy perfluoropolyether, the present invention significantly improves the coating's UV resistance and abrasion resistance, imparting excellent hydrophobic and antifouling properties. Furthermore, the presence of multiple silicon-oxygen bonds effectively enhances the coating's adhesion and improves its durability.

[0014] Preferably, the R1 is selected from any one of the following:

[0015] 、 、 、 .

[0016] More preferably, when said R1 is selected from hour,* 1 Location and connect,* 2 Location and Connection; when the R1 is selected from hour,* 3 Location and connect,* 4 Location and connect.

[0017] Preferably, R2 is selected from any one of the following:

[0018] 、 、 、 、 .

[0019] Preferably, the R3 is selected from any one of the following:

[0020] 、 、 .

[0021] Preferably, m and n are each independently selected from 4 to 8.

[0022] More preferably, m and n have the same value.

[0023] More preferably, the perfluoropolyether siloxane is selected from any one of the following:

[0024] 、 、 、 、 .

[0025] A second object of the present invention is to provide a method for preparing the UV-resistant perfluoropolyether siloxane, the method comprising:

[0026] .

[0027] Dihydroxy perfluoropolyether and diisocyanate undergo substitution reaction A to obtain intermediate 1; the intermediate 1 undergoes substitution reaction B with a small molecule UV absorber to obtain intermediate 2; the intermediate 2 undergoes substitution reaction C with aminosiloxane to obtain perfluoropolyether siloxane.

[0028] Preferably, in the substitution reaction A, the molar ratio of the bishydroxy perfluoropolyether to the diisocyanate is 1:(2-2.5); or / and, in the substitution reaction B, the molar ratio of the intermediate 1 to the small molecule UV absorber is 1:(1-1.2); or / and, in the substitution reaction C, the molar ratio of the intermediate 2 to the aminosiloxane is 1:(1-1.2).

[0029] More preferably, in the substitution reaction A, the molar ratio of the bishydroxy perfluoropolyether to the diisocyanate is 1:(2.3-2.4); or / and, in the substitution reaction B, the molar ratio of the intermediate 1 to the small molecule UV absorber is 1:(1.1-1.2); or / and, in the substitution reaction C, the molar ratio of the intermediate 2 to the aminosiloxane is 1:(1.1-1.2).

[0030] Preferably, the diisocyanate is selected from isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate or diphenylmethane diisocyanate; or / and, the small molecule UV absorber is selected from 2-hydroxy-4-n-octyloxybenzophenone (UV-531), 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole (UV-329), 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (UV-P), 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole (UV-327 ), 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole (UV-326), 2-hydroxy-4-methoxybenzophenone (UV-9) or 2,4-dihydroxybenzophenone (UV-0); or / and, the aminosiloxane is selected from (3-aminopropyl)trimethoxysilane, (3-aminopropyl)triethoxysilane, (3-aminopropyl)dimethylethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane or 3-(2-aminoethylamino)propylmethyldimethoxysilane.

[0031] Preferably, the method comprises:

[0032] 1) Substitution reaction I was carried out by combining bishydroxy perfluoropolyether, diisocyanate, and acetone with dibutyltin diacetate as a catalyst at 50°C under a nitrogen atmosphere to obtain intermediate 1;

[0033] 2) Substitution reaction II is carried out by combining intermediate 1, a small molecule UV absorber, and acetone with potassium hydroxide as a catalyst under a nitrogen atmosphere at 30-50°C to obtain intermediate 2;

[0034] 3) Substitution reaction III is carried out on the intermediate 2, aminosiloxane and acetone under nitrogen atmosphere at room temperature to obtain perfluoropolyethersiloxane.

[0035] Preferably, the amount of dibutyltin diacetate is 0.5-1.0 wt% of the bishydroxy perfluoropolyether; or / and the amount of potassium hydroxide is 1.5-2.5 wt% of the bishydroxy perfluoropolyether.

[0036] The third object of the present invention is to provide the use of the UV-resistant perfluoropolyether siloxane in UV-resistant materials for vehicles.

[0037] The UV-resistant perfluoropolyether siloxane of the present invention, its preparation method, and application solve the problem that the coating of existing AF products is inevitably damaged by ultraviolet rays, and has the following advantages:

[0038] (1) The perfluoropolyether siloxane of the present invention introduces two different functional groups, namely a small molecule UV absorber and an aminosiloxane, onto the bishydroxy perfluoropolyether, significantly improving the UV resistance and abrasion resistance of the coating and imparting an excellent hydrophobic and antifouling effect. In addition, the presence of multiple silicon-oxygen bonds can effectively enhance the adhesion of the coating and improve its durability.

[0039] (2) After the perfluoropolyether siloxane of the present invention is mixed with a fluorine-containing diluent and applied to the surface of a substrate, it exhibits excellent hydrophobic, antifouling, and friction-resistant properties. Importantly, in the QUVB test, after 3000 hours of irradiation, no powdering, blistering, cracking, or peeling occurred, indicating that the coating has extremely strong UV resistance and can meet the requirements for automotive screens.

[0040] (3) The preparation method of UV-resistant perfluoropolyether siloxane of the present invention has the advantages of being simple and easy, having mild reaction conditions and high reaction rate, and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is the hydrogen nuclear magnetic spectrum of the perfluoropolyether siloxane prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0042] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0043] It should be noted that if specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer shall be followed. Reagents or instruments used without manufacturer's indication are all commercially available conventional products.

[0044] Throughout this disclosure, all features, such as values, amounts, amounts, and concentrations, specified in numerical ranges or percentage ranges are provided for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to encompass and specifically disclose all possible subranges and individual values within those ranges (including integers and fractions).

[0045] The features described in this disclosure may be combined in any manner, and as long as there are no conflicts between the combinations of these features, all possible combinations should be considered within the scope of this specification. Each feature disclosed in this specification may be replaced by any alternative feature that provides the same, equivalent, or similar purpose. Therefore, unless otherwise specified, the features disclosed are merely general examples of equivalent or similar features.

[0046] The room temperature in the following examples is 25°C.

[0047] Example 1

[0048] A UV-resistant perfluoropolyether siloxane, the structural formula of which is as follows:

[0049]

[0050] Among them, m=5, n=5.

[0051] The preparation method of the UV-resistant perfluoropolyether siloxane comprises the following steps:

[0052] 1) Bis(hydroxy)perfluoropolyether and isophorone diisocyanate (1:2.3) were weighed and added to a reactor in an acetone solvent. A substitution reaction was carried out at 50°C under a nitrogen atmosphere using dibutyltin diacetate (1.0 wt% of the bis(hydroxy)perfluoropolyether) as a catalyst. After separation and purification, intermediate 1a was obtained.

[0053] The synthetic route of the above substitution reaction is as follows:

[0054]

[0055] 2) Intermediate 1a and UV-531 (2-hydroxy-4-n-octyloxybenzophenone, as a small molecule UV absorber) were weighed at a molar ratio of 1:1.1 and added to a reactor in acetone as the solvent. Potassium hydroxide (2.5 wt% of the bishydroxy perfluoropolyether) was used as a catalyst. A substitution reaction was carried out at 30°C under a nitrogen atmosphere. Intermediate 2a was obtained after extraction and distillation purification.

[0056] The synthetic route of the above substitution reaction is as follows:

[0057]

[0058] 3) Intermediate 2a and 3-aminopropyltrimethoxysilane were weighed at a molar ratio of 1:1.2 and added to a reactor with acetone as the solvent. The substitution reaction was carried out at room temperature under a nitrogen atmosphere. After extraction, the perfluoropolyether siloxane was purified by rotary evaporation to obtain the product.

[0059] The synthetic route of the above substitution reaction is as follows:

[0060]

[0061] Example 2

[0062] A UV-resistant perfluoropolyether siloxane, the structural formula of which is as follows:

[0063]

[0064] Among them, m=5, n=5.

[0065] The preparation method of the UV-resistant perfluoropolyether siloxane comprises the following steps:

[0066] 1) Bis(hydroxy)perfluoropolyether and isophorone diisocyanate (1:2.4) were weighed and added to a reactor in an acetone solvent. A substitution reaction was carried out at 50°C under a nitrogen atmosphere using dibutyltin diacetate (1.0 wt% of the bis(hydroxy)perfluoropolyether) as a catalyst. After separation and purification, intermediate 1a was obtained.

[0067] 2) Intermediate 1a and UV-P (2-(2'-hydroxy-5'-methylphenyl)benzotriazole, a small molecule UV absorber) were weighed at a molar ratio of 1:1.2 and added to a reactor in acetone as the solvent. Potassium hydroxide (2.0 wt% of bishydroxy perfluoropolyether) was used as a catalyst. A substitution reaction was carried out at 35°C under a nitrogen atmosphere. Intermediate 2b was obtained after extraction and distillation.

[0068] The synthetic route of the above substitution reaction is as follows:

[0069]

[0070] 3) Intermediate 2b and 3-aminopropyltriethoxysilane were weighed at a molar ratio of 1:1.1 and added to a reactor using acetone as the solvent. The substitution reaction was carried out at room temperature under a nitrogen atmosphere. After extraction, the perfluoropolyether siloxane was purified by rotary evaporation to obtain the product.

[0071] The synthetic route of the above substitution reaction is as follows:

[0072]

[0073] Example 3

[0074] A UV-resistant perfluoropolyether siloxane, the structural formula of which is as follows:

[0075]

[0076] Among them, m=8, n=8.

[0077] The preparation method of the UV-resistant perfluoropolyether siloxane comprises the following steps:

[0078] 1) Bis(hydroxy)perfluoropolyether and hexamethylene diisocyanate (molar ratio of 1:2.3) were added to a reactor in acetone as the solvent. A substitution reaction was carried out at 50°C under a nitrogen atmosphere using dibutyltin diacetate (0.5 wt% of the bis(hydroxy)perfluoropolyether) as the catalyst. Intermediate 1c was obtained after separation and purification.

[0079] The synthetic route of the above substitution reaction is as follows:

[0080]

[0081] 2) Intermediate 1c and UV-329 (2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, a small molecule UV absorber) were weighed at a molar ratio of 1:1.1 and added to a reactor. The solvent was acetone, and potassium hydroxide (1.5 wt% of the bishydroxy perfluoropolyether) was used as a catalyst. A substitution reaction was carried out at 30°C under a nitrogen atmosphere. Intermediate 2c was obtained after extraction and distillation.

[0082] The synthetic route of the above substitution reaction is as follows:

[0083]

[0084] 3) Intermediate 2c and 3-aminopropyltriethoxysilane were weighed at a molar ratio of 1:1.2 and added to a reactor using acetone as the solvent. The substitution reaction was carried out at room temperature under a nitrogen atmosphere. After extraction, the perfluoropolyether siloxane was purified by rotary evaporation to obtain the product.

[0085] The synthetic route of the above substitution reaction is as follows:

[0086]

[0087] Example 4

[0088] A UV-resistant perfluoropolyether siloxane, the structural formula of which is as follows:

[0089]

[0090] Among them, m=6, n=6;

[0091] The preparation method of the UV-resistant perfluoropolyether siloxane comprises the following steps:

[0092] 1) Bis(hydroxy)perfluoropolyether and toluene diisocyanate (toluene diisocyanate) at a molar ratio of 1:2.3 were added to a reactor in acetone as the solvent. A substitution reaction was carried out at 50°C under a nitrogen atmosphere using dibutyltin diacetate (1.0 wt% of the bis(hydroxy)perfluoropolyether) as the catalyst. After separation and purification, intermediate 1d was obtained.

[0093] The synthetic route of the above substitution reaction is as follows:

[0094]

[0095] 2) Intermediate 1d and UV-327 (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, a small molecule UV absorber) were weighed at a molar ratio of 1:1.1 and added to a reactor. The solvent was acetone, and potassium hydroxide (2.5 wt% of bishydroxy perfluoropolyether) was used as a catalyst. A substitution reaction was carried out at 35°C under a nitrogen atmosphere. Intermediate 2d was obtained after extraction and distillation.

[0096] The synthetic route of the above substitution reaction is as follows:

[0097]

[0098] 3) Intermediate 2d and (3-aminopropyl)dimethylethoxysilane were weighed at a molar ratio of 1:1.2 and added to a reactor in acetone. The substitution reaction was carried out at room temperature under a nitrogen atmosphere. After extraction, the perfluoropolyether siloxane was purified by rotary evaporation to obtain the product.

[0099] The synthetic route of the above substitution reaction is as follows:

[0100]

[0101] Example 5

[0102] A UV-resistant perfluoropolyether siloxane, the structural formula of which is as follows:

[0103]

[0104] Among them, m=4, n=4;

[0105] The preparation method of the UV-resistant perfluoropolyether siloxane comprises the following steps:

[0106] 1) Bis(hydroxy)perfluoropolyether and diphenylmethane diisocyanate (DPI) at a molar ratio of 1:2.4 were added to a reactor in acetone as the solvent and dibutyltin diacetate (1.0 wt% of the bis(hydroxy)perfluoropolyether) as the catalyst. A substitution reaction was carried out at 50°C under a nitrogen atmosphere. After separation and purification, the intermediate 1f was obtained.

[0107] The synthetic route of the above substitution reaction is as follows:

[0108]

[0109] 2) Intermediate 1f and UV-0 (2,4-dihydroxybenzophenone, as a small molecule UV absorber) were weighed at a molar ratio of 1:1.2 and added to a reactor in acetone as the solvent. Potassium hydroxide (2.5 wt% of bishydroxy perfluoropolyether) was used as a catalyst. A substitution reaction was carried out at 50°C under a nitrogen atmosphere. Intermediate 2f was obtained after extraction and distillation purification.

[0110] The synthetic route of the above substitution reaction is as follows:

[0111]

[0112] 3) Intermediate 2f and 3-(2-aminoethylamino)propyltriethoxysilane were weighed at a molar ratio of 1:1.2 and added to a reactor in acetone. The solvent was acetone and the substitution reaction was carried out at room temperature under a nitrogen atmosphere. After extraction, the perfluoropolyether siloxane was purified by rotary evaporation to obtain the product.

[0113] The synthetic route of the above substitution reaction is as follows:

[0114]

[0115] Comparative Example 1

[0116] Compared with Example 1, this comparative example has the following differences:

[0117] Without adding UV531, step 2 in Example 1 was omitted, and the remaining preparation steps were the same.

[0118] Comparative Example 2

[0119] Compared with Example 1, this comparative example has the following differences:

[0120] Without adding 3-aminopropyltrimethoxysilane, step 3 in Example 1 was omitted, and the remaining preparation steps were the same.

[0121] Comparative Example 3

[0122] Compared with Example 1, this comparative example has the following differences:

[0123] In step 1), the molar ratio of bishydroxy perfluoropolyether and isophorone diisocyanate is 1:1, and the remaining preparation steps are the same.

[0124] Experimental Example 1 Performance Test

[0125] The perfluoropolyether siloxane prepared in Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 was uniformly mixed with a fluorinated diluent (3M fluorinated liquid HFE-7100) at a mass ratio of 0.5:99.5. The mixture was evenly and precisely applied to the surface of the substrate by spraying or painting, and then heated and cured at 90°C. The obtained film thickness data is shown in Table 1.

[0126] By testing the light transmittance, initial water drop angle, rubber friction resistance, UV resistance and other properties of the substrate surface, the details are as follows:

[0127] 1) Light transmittance test method: Light transmittance is measured by a TH-110 light transmittance haze meter. Place the coated substrate on the test platform and press the HOLD button of the instrument. Once the instrument has completed self-calibration, the test can begin and the test results can be recorded.

[0128] 2) Hydrophobicity Angle Test Method: The static contact angle of the coating is measured using a JGW-360a contact angle meter. The test liquid volume is 2 μL, and the test environment is 24 ± 1°C and 45 ± 1% relative humidity. The water droplet contact angle is measured at five points and the average value is taken.

[0129] 3) Steel wool abrasion resistance test method: The steel wool abrasion resistance test is measured using a ZJ-339-GSR abrasion tester. The coated substrate is fixed to the tester with a MUN BANGSAWOO rubber eraser. The pressure is set to 1000g, the stroke is set to 40mm, and the speed is 40 cycles / min. After the test, the water drop angle test results of the substrate are recorded.

[0130] 4) Weathering performance test method: Refer to GB / T 14522-2008 for testing. The test results are based on the standard of no powdering, blistering, cracking, or peeling of the film layer. The longest UV exposure time is recorded.

[0131] Table 1 Substrate performance test results

[0132]

[0133] The test results are shown in Table 1. From the data of Examples 1 to 5, it can be seen that after the new UV-resistant perfluoropolyether siloxane prepared by the technical solution of the present invention is mixed with a fluorinated diluent and applied to a substrate, the water contact angle on its surface is greater than 120°, showing good hydrophobic and antifouling properties. In addition, after QUVB testing, the surface coatings of the substrates of Examples 1 to 5 still did not show any powdering, blistering, cracking, or peeling after 3000 hours, indicating that the coatings have extremely strong UV resistance and can meet the requirements for use in vehicle-mounted screens. In Comparative Examples 1 to 3, due to the lack of the main functional groups, each coating performed poorly in terms of initial hydrophobic angle, UV resistance, and steel wool friction resistance, and could not meet the requirements for use.

[0134] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. After reading the above description, various modifications and substitutions of the present invention will become apparent to those skilled in the art. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A UV-resistant perfluoropolyether siloxane, characterized in that: The chemical structural formula of the perfluoropolyether siloxane is shown in Formula I: Formula I In formula I, m and n are each independently an integer greater than or equal to 1; R1 is selected from 、 、 、 or ; R2 is selected from 、 、 、 、 、 or ; R3 is selected from 、 、 、 、 or ; * in each substituent group indicates a bonding position.

2. The UV-resistant perfluoropolyether siloxane according to claim 1, wherein The R1 is selected from any one of the following: 、 、 、 ； Or / and, said R2 is selected from any one of the following: 、 、 、 、 ； Or / and, said R3 is selected from any one of the following: 、 、 。 3. The UV-resistant perfluoropolyether siloxane according to claim 1, wherein The m and n are each independently 4 to 8.

4. The UV-resistant perfluoropolyether siloxane according to claim 1, wherein The perfluoropolyether siloxane is selected from any one of the following: 、 、 、 、 。 5. The method for preparing a UV-resistant perfluoropolyether siloxane according to any one of claims 1 to 4, wherein: The method includes: ； Dihydroxy perfluoropolyether and diisocyanate undergo substitution reaction A to obtain intermediate 1; the intermediate 1 undergoes substitution reaction B with a small molecule UV absorber to obtain intermediate 2; the intermediate 2 undergoes substitution reaction C with aminosiloxane to obtain perfluoropolyether siloxane.

6. The preparation method according to claim 5, characterized in that In the substitution reaction A, the molar ratio of the bishydroxy perfluoropolyether to the diisocyanate is 1:(2-2.5); Or / and, in the substitution reaction B, the molar ratio of the intermediate 1 to the small molecule UV absorber is 1:(1-1.2); Or / and, in the substitution reaction C, the molar ratio of the intermediate 2 to the aminosiloxane is 1:(1-1.2).

7. The preparation method according to claim 5, characterized in that The diisocyanate is selected from isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate or diphenylmethane diisocyanate; Or / and, the small molecule UV absorber is selected from 2-hydroxy-4-n-octyloxybenzophenone, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone or 2,4-dihydroxybenzophenone; Or / and, the aminosiloxane is selected from (3-aminopropyl)trimethoxysilane, (3-aminopropyl)triethoxysilane, (3-aminopropyl)dimethylethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane or 3-(2-aminoethylamino)propylmethyldimethoxysilane.

8. The preparation method according to claim 5, characterized in that The method includes: 1) Substitution reaction I was carried out by combining bishydroxy perfluoropolyether, diisocyanate, and acetone with dibutyltin diacetate as a catalyst at 50°C under a nitrogen atmosphere to obtain intermediate 1; 2) Substitution reaction II is carried out by combining intermediate 1, a small molecule UV absorber, and acetone with potassium hydroxide as a catalyst under a nitrogen atmosphere at 30-50°C to obtain intermediate 2; 3) Substitution reaction III is carried out on the intermediate 2, aminosiloxane and acetone under nitrogen atmosphere at room temperature to obtain perfluoropolyethersiloxane.

9. The preparation method according to claim 8, characterized in that The amount of dibutyltin diacetate is 0.5-1.0 wt% of the bishydroxy perfluoropolyether; Or / and, the amount of potassium hydroxide used is 1.5-2.5 wt% of the bishydroxy perfluoropolyether.

10. Use of the UV-resistant perfluoropolyether siloxane according to any one of claims 1 to 4 in a UV-resistant material for vehicles.

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