UV-resistant perfluoropolyether siloxane as well as preparation method and application thereof

Abstract

The invention discloses UV-resistant perfluoropolyether siloxane as well as a preparation method and application thereof, the chemical structural formula of the perfluoropolyether siloxane is as shown in formula I, and in the formula I, m and n are independently integers greater than or equal to 1. According to the invention, two functional groups with different functions, such as the micromolecular UV absorbent and the amino siloxane, are respectively introduced into the dihydroxyl perfluoropolyether, so that the UV resistance, the wear resistance and the like of the coating are remarkably improved, and excellent hydrophobic and antifouling effects are achieved. In addition, due to the existence of multiple silicon-oxygen bonds, the adhesive force of the coating can be effectively enhanced, and the durability is improved. And the formula I of the # imgabs0 # is shown in the specification.

Description

Technical Field

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

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

[0003] At present, there are many AF (perfluorinated amorphous fluororesin material) products on the market, which can give the surface a good waterproof and oleophobic layer, and it is not easy to cause damage when wiping the surface, which can effectively improve the user experience. However, in the long-term use process, the coating will inevitably be damaged by ultraviolet rays, causing the coating to crack and yellow, and then its anti-fingerprint and anti-scratch performance will be weakened or even disappear. Therefore, it is necessary to develop a UV-resistant AF product dedicated to automobiles.

[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 the 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 a preparation method and application thereof, which solves the problem that the coating of existing AF products will inevitably be damaged by ultraviolet rays, can significantly improve the UV resistance, wear resistance and other properties 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: Formula I In formula I, m and n are integers greater than or equal to 1; R1 is selected from , , , or ; R2 is selected from , , , , , or ; R3 is selected from , , , , or ; The * in each substituent group indicates a bonding position.

[0007] The present invention significantly improves the UV resistance and abrasion resistance of the coating by introducing two different functional groups, such as a small molecule UV absorber and an aminosiloxane, into the bishydroxy perfluoropolyether, and imparts 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.

[0008] Preferably, the R1 is selected from any one of the following: , , , .

[0009] 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.

[0010] Preferably, R2 is selected from any one of the following: , , , , .

[0011] Preferably, the R3 is selected from any one of the following: , , .

[0012] Preferably, m and n are each independently selected from 4 to 8.

[0013] More preferably, m and n have the same value.

[0014] More preferably, the perfluoropolyether siloxane is selected from any one of the following: , , , , .

[0015] The second object of the present invention is to provide a method for preparing the UV-resistant perfluoropolyether siloxane, the method comprising: .

[0016] 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.

[0017] Preferably, in the substitution reaction A, the molar ratio of the dihydroxy 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).

[0018] More preferably, in the substitution reaction A, the molar ratio of the dihydroxy 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).

[0019] 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.

[0020] Preferably, the method comprises: 1) Dihydroxy perfluoropolyether, diisocyanate and acetone were subjected to substitution reaction I at 50°C under nitrogen atmosphere with dibutyltin diacetate as a catalyst to obtain intermediate 1; 2) intermediate 1, a small molecule UV absorber and acetone are subjected to substitution reaction II in a nitrogen atmosphere at 30-50°C with potassium hydroxide as a catalyst to obtain intermediate 2; 3) The intermediate 2, aminosiloxane and acetone are subjected to substitution reaction III under a nitrogen atmosphere at room temperature to obtain perfluoropolyether siloxane.

[0021] 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.

[0022] The third object of the present invention is to provide the use of the UV-resistant perfluoropolyether siloxane in UV-resistant materials for vehicles.

[0023] The UV-resistant perfluoropolyether siloxane of the present invention and its preparation method and application solve the problem that the coating of the existing AF products will inevitably be damaged by ultraviolet rays, and have the following advantages: (1) The perfluoropolyether siloxane of the present invention introduces two functional groups with different functions, namely, a small molecule UV absorber and an aminosiloxane, on the bishydroxy perfluoropolyether, which significantly improves the UV resistance and abrasion resistance of the coating and provides excellent hydrophobic and antifouling effects. In addition, the presence of multiple silicon oxygen bonds can effectively enhance the adhesion of the coating and improve its durability;

[0024] (2) After the perfluoropolyether siloxane of the present invention is mixed with a fluorine-containing diluent and applied to the surface of the substrate, it exhibits excellent hydrophobic, antifouling and friction-resistant properties. Importantly, in the QUVB test, after 3000 hours of irradiation, there is still no powdering, blistering, cracking, peeling and other phenomena, indicating that the coating has extremely strong UV resistance and can meet the requirements for the use of vehicle-mounted screens;

[0025] (3) The method for preparing UV-resistant perfluoropolyether siloxane of the present invention has the advantages of being simple and easy to operate, mild reaction conditions, and high reaction rate, and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the hydrogen nuclear magnetic spectrum of the perfluoropolyether siloxane prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] It should be noted that if the specific conditions are not specified in the examples, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased from the market.

[0029] In the present invention, all features defined in the form of numerical ranges or percentage ranges, such as values, quantities, contents and concentrations, are only for brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be deemed to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0030] The features mentioned in the present invention can be combined arbitrarily, as long as there is no contradiction in the combination of these features, all possible combinations should be considered as the scope of this specification. Each feature disclosed in the specification can be replaced by any alternative feature that can provide the same, equal or similar purpose. Therefore, unless otherwise specified, the disclosed features are only general examples of equal or similar features.

[0031] The room temperature in the following examples is 25°C.

[0032] Example 1 A UV-resistant perfluoropolyether siloxane, the structural formula of which is as follows:

[0033] Among them, m=5, n=5.

[0034] The preparation method of the UV-resistant perfluoropolyether siloxane comprises the following steps: 1) Weighing bishydroxy perfluoropolyether and isophorone diisocyanate in a molar ratio of 1:2.3 into a reactor, using acetone as the solvent, using dibutyltin diacetate accounting for 1.0 wt% of bishydroxy perfluoropolyether as the catalyst, carrying out a substitution reaction at 50°C under a nitrogen atmosphere, and obtaining intermediate 1a after separation and purification; The synthetic route of the above substitution reaction is as follows:

[0035] 2) Weighing the intermediate 1a and UV-531 (2-hydroxy-4-n-octyloxybenzophenone, as a small molecule UV absorber) in a molar ratio of 1: 1.1, adding them into a reactor, using acetone as the solvent, using potassium hydroxide accounting for 2.5 wt% of the bishydroxy perfluoropolyether as a catalyst, and carrying out a substitution reaction at 30°C under a nitrogen atmosphere, extracting and distilling to obtain intermediate 2a; The synthetic route of the above substitution reaction is as follows:

[0036] 3) The intermediate 2a and 3-aminopropyltrimethoxysilane in a molar ratio of 1:1.2 were weighed and added into 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.

[0037] The synthetic route of the above substitution reaction is as follows:

[0038] Example 2 A UV-resistant perfluoropolyether siloxane, the structural formula of which is as follows:

[0039] Among them, m=5, n=5.

[0040] The preparation method of the UV-resistant perfluoropolyether siloxane comprises the following steps: 1) Weighing bishydroxy perfluoropolyether and isophorone diisocyanate in a molar ratio of 1:2.4 into a reactor, using acetone as the solvent, using dibutyltin diacetate accounting for 1.0 wt% of bishydroxy perfluoropolyether as the catalyst, carrying out a substitution reaction at 50°C under a nitrogen atmosphere, and obtaining intermediate 1a after separation and purification; 2) Weighing the intermediate 1a and UV-P (2-(2'-hydroxy-5'-methylphenyl)benzotriazole, as a small molecule UV absorber) in a molar ratio of 1:1.2, adding them into a reactor, using acetone as the solvent, using potassium hydroxide accounting for 2.0wt% of the bishydroxy perfluoropolyether as the catalyst, and carrying out substitution reaction at 35°C under a nitrogen atmosphere, extracting and distilling to obtain intermediate 2b; The synthetic route of the above substitution reaction is as follows:

[0041] 3) The intermediate 2b and 3-aminopropyltriethoxysilane in a molar ratio of 1:1.1 were weighed and added into 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.

[0042] The synthetic route of the above substitution reaction is as follows:

[0043] Example 3 A UV-resistant perfluoropolyether siloxane, the structural formula of which is as follows:

[0044] Among them, m=8, n=8.

[0045] The preparation method of the UV-resistant perfluoropolyether siloxane comprises the following steps: 1) Weighing bishydroxy perfluoropolyether and hexamethylene diisocyanate in a molar ratio of 1:2.3 into a reactor, using acetone as the solvent, using dibutyltin diacetate accounting for 0.5 wt% of bishydroxy perfluoropolyether as the catalyst, carrying out substitution reaction at 50°C under a nitrogen atmosphere, and obtaining intermediate 1c after separation and purification; The synthetic route of the above substitution reaction is as follows:

[0046] 2) Weighing the intermediate 1c and UV-329 (2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, as a small molecule UV absorber) in a molar ratio of 1:1.1, adding them into a reactor, using acetone as the solvent, using potassium hydroxide accounting for 1.5wt% of the bishydroxy perfluoropolyether as the catalyst, and carrying out substitution reaction at 30°C under a nitrogen atmosphere, extracting and distilling to obtain intermediate 2c; The synthetic route of the above substitution reaction is as follows:

[0047] 3) The intermediate 2c and 3-aminopropyltriethoxysilane in a molar ratio of 1:1.2 were weighed and added into 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.

[0048] The synthetic route of the above substitution reaction is as follows:

[0049] Example 4 A UV-resistant perfluoropolyether siloxane, the structural formula of which is as follows:

[0050] Among them, m=6, n=6; The preparation method of the UV-resistant perfluoropolyether siloxane comprises the following steps: 1) Weighing bishydroxy perfluoropolyether and toluene diisocyanate in a molar ratio of 1:2.3 into a reactor, using acetone as the solvent, using dibutyltin diacetate accounting for 1.0 wt% of bishydroxy perfluoropolyether as the catalyst, carrying out a substitution reaction at 50°C under a nitrogen atmosphere, and obtaining intermediate 1d after separation and purification; The synthetic route of the above substitution reaction is as follows:

[0051] 2) Weighing the intermediate 1d and UV-327 (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, as a small molecule UV absorber) in a molar ratio of 1:1.1, adding them into a reactor, using acetone as the solvent, using potassium hydroxide accounting for 2.5wt% of the bishydroxy perfluoropolyether as the catalyst, and carrying out a substitution reaction at 35°C under a nitrogen atmosphere, extracting and distilling to purify to obtain the intermediate 2d; The synthetic route of the above substitution reaction is as follows:

[0052] 3) The intermediate 2d and (3-aminopropyl)dimethylethoxysilane in a molar ratio of 1:1.2 were weighed and added into 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 perfluoropolyether siloxane.

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

[0054] Example 5 A UV-resistant perfluoropolyether siloxane, the structural formula of which is as follows:

[0055] Among them, m=4, n=4; The preparation method of the UV-resistant perfluoropolyether siloxane comprises the following steps: 1) Weighing bishydroxy perfluoropolyether and diphenylmethane diisocyanate in a molar ratio of 1:2.4 and adding them into a reactor, using acetone as the solvent, using dibutyltin diacetate accounting for 1.0 wt% of bishydroxy perfluoropolyether as the catalyst, carrying out substitution reaction at 50°C under a nitrogen atmosphere, and obtaining intermediate 1f after separation and purification; The synthetic route of the above substitution reaction is as follows:

[0056] 2) The intermediate 1f and UV-0 (2,4-dihydroxybenzophenone, as a small molecule UV absorber) in a molar ratio of 1:1.2 were weighed and added into a reactor, the solvent was acetone, potassium hydroxide accounting for 2.5wt% of the bishydroxy perfluoropolyether was used as a catalyst, and a substitution reaction was carried out at 50°C under a nitrogen atmosphere, and the intermediate 2f was obtained after extraction and distillation purification; The synthetic route of the above substitution reaction is as follows:

[0057] 3) The intermediate 2f and 3-(2-aminoethylamino)propyltriethoxysilane in a molar ratio of 1:1.2 were weighed and added into 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.

[0058] The synthetic route of the above substitution reaction is as follows:

[0059] Comparative Example 1 Compared with Example 1, the difference between this comparative example is: Without adding UV531, without step 2 in Example 1), the remaining preparation steps are the same.

[0060] Comparative Example 2 Compared with Example 1, the difference between this comparative example is: Without adding 3-aminopropyltrimethoxysilane, step 3 in Example 1 is omitted, and the remaining preparation steps are the same.

[0061] Comparative Example 3 Compared with Example 1, the difference between this comparative example is: In step 1), the molar ratio of dihydroxy perfluoropolyether to isophorone diisocyanate is 1:1, and the remaining preparation steps are the same.

[0062] Experimental Example 1 Performance Test The perfluoropolyether siloxane prepared in Examples 1, 2, 3 and Comparative Examples 1, 2, 3 was uniformly mixed with a fluorinated diluent (3M fluorinated liquid HFE-7100) at a mass ratio of 0.5:99.5, and was uniformly and precisely applied to the surface of the substrate by spraying or applying, and then heated and cured at 90°C. The obtained film thickness data is shown in Table 1.

[0063] 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: 1) Transmittance test method: The transmittance is measured by a TH-110 transmittance haze meter. Place the coated substrate on the test platform, press the HOLD key of the instrument, and start the test after the instrument passes self-calibration, and record the test results.

[0064] 2) Hydrophobic angle test method: The static contact angle of the coating is measured by a JGW-360a contact angle meter. The test liquid volume is 2μL, the test environment is 24±1℃, and the relative humidity is 45±1%. The water droplet touch angle is measured at 5 points and the average value is taken.

[0065] 3) Steel wool abrasion resistance test method: The steel wool abrasion resistance test is measured by ZJ-339-GSR wear tester. The coated substrate is fixed on the tester. The rubber model is MUNBANGSAWOO, the pressure is set to 1000g, the stroke is set to 40mm, and the speed is 40cycles / min. After the test, the water drop angle test result of the substrate is recorded.

[0066] 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, and the longest UV exposure time is recorded.

[0067] Table 1 Substrate performance test results

[0068] 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 the QUVB test, the surface coatings of the substrates of Examples 1 to 5 still did not show powdering, blistering, cracking, peeling, etc. after 3000 hours, indicating that the coatings have extremely strong UV resistance and can meet the requirements for the use of 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 use requirements.

[0069] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited 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 ; The * in each substituent group indicates a bonding position.

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

4. The UV-resistant perfluoropolyether siloxane according to claim 1, characterized in that 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, characterized in that: 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 dihydroxy 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) Dihydroxy perfluoropolyether, diisocyanate and acetone were subjected to substitution reaction I at 50°C under nitrogen atmosphere with dibutyltin diacetate as a catalyst to obtain intermediate 1; 2) intermediate 1, a small molecule UV absorber and acetone are subjected to substitution reaction II in a nitrogen atmosphere at 30-50°C with potassium hydroxide as a catalyst to obtain intermediate 2; 3) The intermediate 2, aminosiloxane and acetone are subjected to substitution reaction III under a nitrogen atmosphere at room temperature to obtain perfluoropolyether siloxane.

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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