Preparation method and application of perfluoropolyether modified acrylate compound

Abstract

The invention relates to a preparation method and application of a perfluoropolyether modified acrylate compound. The compound takes a perfluoropolyether hydroxyl group or a perfluoropolyether amino substance as a raw material, and is bonded to one end through a carbamate bond and bonded to the other end through a carbamate bond. The compound can be dissolved in common solvents and can be applied to different coating systems; and after UV curing film forming, good initial contact angle and wear resistance can be provided. Therefore, the compound can be used as an additive for ensuring initial contact angle and wear resistance in a UV photocurable coating.

Description

Technical Field

[0001] The invention relates to the technical field of polymer fluorine materials, and in particular to a preparation method and application of a perfluoropolyether modified acrylate compound. Background Art

[0002] UV light curing surface treatment technology has the advantages of less environmental pollution, high coating quality and low energy consumption, so it is widely used. However, the cured coating not only needs to provide protection from scratches and wear, but also needs to have the ability to resist tiny pollutants such as water, sweat, and grease. However, the main resin in the coating composition has a high surface tension, and the surface energy of the prepared coating is high, resulting in poor hydrophobic and oleophobic ability, thereby affecting the performance. Therefore, it is a quick, efficient and practical method to study the addition of an efficient anti-fouling additive to the existing coating formula without changing the other properties of the original coating.

[0003] Perfluoropolyether (PFPE) polymers have excellent properties such as hydrophobicity and oleophobicity, heat resistance, and low surface free energy. Adding fluorinated polymers to coatings can migrate to the surface and enrich during the curing process, thereby giving the coating hydrophobicity, oleophobicity, high lubricity, and self-cleaning properties.

[0004] For example, patent US20110293943A1 discloses a fluoroalkyl (meth) acrylate copolymer, which uses short fluoroalkyl groups with 2 to 6 carbon atoms as additives for alkyd paints or polymer resins to provide durable surface effects. However, the short fluorine chain limits the migration of more fluorine segments to the surface, and the thin fluorinated surface is easily consumed, resulting in poor wear resistance and hydrophobicity and oleophobicity of the cured coating.

[0005] Another example is CN101395191A, which discloses a high-energy ray-curing composition, which introduces perfluoropolyether into a UV light-curing composition and achieves good results. It contains a fluoride with multiple unsaturated bonds synthesized from polyisocyanate, PFPE-CH2OH and hydroxyethyl acrylate. However, the molecular weight of PFPE in the composition is relatively small, and the coating formed after curing has average performance in terms of anti-fingerprint and friction resistance.

[0006] However, due to the low surface free energy of perfluoropolyether-based compounds, the compatibility and affinity of other substances with relatively large molecular weight are very low. If the perfluoropolyether-based compounds are added to various industrial materials and given the above properties, problems will arise in terms of dispersion stability and reactivity, causing the perfluoropolyether-based compounds to be difficult to be matched to various industrial materials. The surface free energy of polysiloxane compounds is also low, and the affinity to other substances is good, and the dispersion stability can be further improved by carrying out various modifications. In view of this, it is of great significance and great industrial value to develop perfluoropolyether-organopolysiloxane acrylate compounds with the characteristics of both perfluoropolyether and polysiloxane and the excellent affinity with non-fluorine-based organic compounds and to give the properties such as water-repellent and oil-repellent of cured coating. Summary of the invention

[0007] In view of the above technical problems and the shortcomings in the art, the purpose of the present invention is to provide a preparation method and application of a perfluoropolyether modified acrylate compound. The method is simple, easy to operate, the raw materials are readily available, the reaction conditions are mild, and it is safe and environmentally friendly. The coating formed by using the method in a surface treatment agent has good water resistance, wear resistance and excellent antifouling performance.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: (1) Add diisocyanate and a certain amount of catalyst and solvent into a reactor, slowly drop perfluoropolyether alcohol into the reactor under the protection of an inert atmosphere, raise the temperature to 30-70°C, and react for 1-12 hours until the -NCO group reaches the theoretical content, thereby obtaining an intermediate product 1.

[0009] The diisocyanate includes at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate and other diisocyanates.

[0010] The catalyst is organic tin, organic titanium and other metal organic catalysts.

[0011] In some embodiments, the organotin is selected from any one of dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dioctoate, dioctyltin diacetate, dioctyltin dilaurate, dioctyltin dioctoate, and stannous dioctoate.

[0012] The organic titanium is selected from any one of titanate or titanium chelate compounds such as tetraisopropoxy titanium, tetra-n-butoxy titanium, tetra(2-ethylhexyloxy) titanium, dipropoxybis(acetylacetonate) titanium, isopropoxy octanediol titanium, etc.

[0013] The solvent is perfluorohexane, perfluoromethylcyclohexane, perfluoro-1, 3-dimethylcyclohexane, bis(trifluoromethyl)benzene, 3,3-pentafluorobutane, HCFC-225, perfluoropropyl methyl ether, perfluorobutyl methyl ether, perfluorobutyl ethyl ether, perfluorohexyl methyl ether or CF 3 CH 2 OCF 2 CHF 2 At least one of the fluorinated solvents.

[0014] The molar ratio of the diisocyanate to the perfluoropolyether alcohol is 1-1.5:1; the inert atmosphere is a nitrogen atmosphere and / or a rare gas atmosphere; the perfluoropolyether alcohol is one of Z-type, K-type, Y-type, and D-type alcohol, and has a molecular weight of 500 to 20,000.

[0015] (2) Methyltriethoxysilane and diisopropanolamine are mixed, and p-toluenesulfonic acid is added to carry out a catalytic reaction to obtain a terminal hydroxyl hyperbranched polymerization intermediate product 2 containing a siloxane structure; It is understandable to those skilled in the art that after obtaining the hydroxyl-terminated hyperbranched polymer intermediate product 2 containing a siloxane structure, the same solvent as in step (1) is used for dissolution to facilitate the reaction in step (3).

[0016] The molar ratio of the methyltriethoxysilane to diisopropanolamine is 1:3-10; the total amount of the p-toluenesulfonic acid added is 0.01-10wt% of the total mass of the methyltriethoxysilane and diisopropanolamine.

[0017] The conditions of the catalytic reaction are: heating at 60-150° C. for 1-2 h under nitrogen protection; then stopping the introduction of nitrogen and distilling under reduced pressure at 60-150° C. for 1-2 h.

[0018] (3) The intermediate product 1 is added to the product 2, and after heating and reacting for a period of time, an isocyanate-containing acrylate compound is added to continue the reaction for a period of time and then terminated.

[0019] It is understandable to those skilled in the art that after adding the isocyanate-containing acrylate compound, the catalyst dibutyltin dilaurate needs to be added, and the dibutyltin dilaurate can be added directly in the first step without further addition. The catalytic reaction is carried out under any solvent conditions described in step (1).

[0020] The adding method is dropwise addition; the reaction temperature is 30-100° C., and the reaction time is 1-12 h; the molar ratio of the intermediate product 1 to the product 2 is 1:0.5-2; the molar ratio of the isocyanate-containing acrylate compound to the product 2 is 1:0.5-1; the isocyanate-containing acrylate compound is a common compound in the art such as isocyanate ethyl methacrylate (IEM), isocyanate ethyl acrylate (AOI), etc.

[0021] The technologies not mentioned in the present invention are all referred to the prior art.

[0022] Another technical solution adopted by the present invention is to provide an application of a perfluoropolyether modified acrylate compound in UV light-curing paints and coatings.

[0023] Compared with the prior art, the present invention has the following beneficial effects: The perfluoropolyether modified acrylate compound of the present invention has a simple preparation method, is easy to operate, has readily available raw materials, and has mild reaction conditions, and is safe and environmentally friendly.

[0024] Meanwhile, the perfluoropolyether modified acrylate compound prepared by the present invention has good compatibility with non-fluorine organic solvents by introducing a polysiloxane block in the middle of the molecular chain and generating a plurality of (meth)acryloyl groups after the reaction.

[0025] Secondly, after being added to the coating as an anti-fouling additive, it is not easy to produce uneven parts and white turbid parts in the obtained cured product. It can give the substrate excellent waterproof, oil-proof, anti-fouling and anti-fingerprint properties. After curing, the water contact angle is above 110° and the oil contact angle is above 68°. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the structural formula of the terminal hydroxyl hyperbranched polymer of Synthesis Example 2.

[0027] Figure 2 This is the structural formula of PFPE-1. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0029] Synthesis example 1 Add 0.67g (3mmol) of isophorone diisocyanate, 8g of m-ditrifluorotoluene solvent and 0.16g of dibutyltin dilaurate to the reaction bottle and stir evenly. Then, weigh 11.4g of perfluoropolyether alcohol (Mn=3800g / mol, 3mmol) and dissolve it in 12g of m-ditrifluorotoluene. Slowly add it dropwise to the reaction bottle through a constant pressure separatory funnel under a nitrogen atmosphere. After the addition is completed, heat it to 50°C and continue the reaction. After the -OH group reacts completely as determined by infrared spectroscopy, stop the reaction to obtain a solution of intermediate product 1; Synthesis example 2 0.41 g (3 mmol) of methyltriethoxysilane, 1.2 g (9 mmol) of diisopropanolamine and 0.009 g of p-toluenesulfonic acid were weighed and added to a reaction bottle. After reacting for 2 h under mechanical stirring, nitrogen atmosphere and 100 ° C, the nitrogen was turned off, the pressure was reduced and vacuumed, and the reaction was continued at 110 ° C for 2 h. Then the vacuum pump was turned off, and 1.224 g (9 mmol) of methyltriethoxysilane, 2.394 g of diisopropanolamine and 0.026 g of p-toluenesulfonic acid were added to the flask, and the reaction was continued at 100 ° C for 2 h, and then the nitrogen was turned off, the pressure was reduced and vacuumed, and the reaction was continued at 110 ° C for 2 h, and the vacuum pump was turned off. The substance in the reaction bottle was dissolved with 20 g of m-ditrifluorotoluene to obtain a terminal hydroxyl hyperbranched polymerization intermediate 2 containing a siloxane structure.

[0030] Synthesis example 3 Under nitrogen atmosphere, the intermediate product 1 of Synthesis Example 1 was slowly added dropwise to the intermediate product 2 of Synthesis Example 2 through a constant pressure separatory funnel and stirred evenly. After the addition was completed, the temperature was raised to 50°C and the reaction was continued. The infrared spectrum was measured at 2270 cm -1 After there is no characteristic peak of -NCO, cool down, add 2.4g (15.5mmol) of methacryloyloxyethyl isocyanate and 0.2g of dibutyltin dilaurate, 0.05g of p-hydroxyanisole, react at 60°C for 8 hours, concentrate the reaction solution, dissolve and dilute it with methyl isobutyl ketone to 20%wt to obtain the anti-fouling additive PFPE-1.

[0031] Synthesis example 4 According to the steps and processes shown in Synthesis Example 1-3, the perfluoropolyether was replaced with 3g (Mn=1000g / mol, 3mmol), and the other conditions and masses were the same as those in Synthesis Example 1-3 to prepare the antifouling additive PFPE-2.

[0032] The core point is that the antifouling agent PFPE-1 obtained in Synthesis Example 3 introduces polysiloxane to increase the solubility of PFPE-1. The amount of perfluoropolyether is set because of its different molecular weights, and the corresponding results obtained in subsequent applications are also different. The smaller the molecular weight, the better the solubility, but the worse the performance. On the contrary, the larger the molecular weight, the worse the solubility, but the better the performance.

[0033] Synthesis example 5 According to the steps and processes shown in Synthesis Example 1-3, the perfluoropolyether was replaced with 5.8 g (Mn=1934 g / mol, 3 mmol), and the other conditions and masses were the same as those in Synthesis Example 1-3 to prepare the antifouling agent PFPE-3.

[0034] Example 1 20%wt of trifunctional acrylate (TMPAT, allnex), 20%wt of hexafunctional acrylate (EB1290, allnex), 3%wt of IRGACURE 184 as a photoinitiator and 57%wt of butyl acetate as a solvent were mixed and filtered. The PFPE-1 compound obtained in Synthesis Example 3 was added in an amount of 1wt% of the coating system and mixed evenly. The coating composition was applied to a PET substrate to form a coating with a thickness of about 5um. After drying the solvent, 1600mJ / cm 2 The coating film is prepared by irradiating with a UV lamp for a curing time of 5-30 seconds.

[0035] Example 2 A coating film was prepared in the same manner as in Example 1, except that the PFPE-1 compound was added to the coating system in an amount of 0.5 wt %.

[0036] Example 3 A coating film was prepared in the same manner as in Example 1, except that the compound of Formula PFPE-2 obtained in Synthesis Example 4 was used instead of the compound of Formula PFPE-1.

[0037] Example 4 A coating film was prepared in the same manner as in Example 1, except that the compound of Formula PFPE-3 obtained in Synthesis Example 5 was used instead of the compound of Formula PFPE-1.

[0038] Comparative Example 1 Add 4g perfluoropolyether alcohol (Mn=1000g / mol, 4mmol) and 10ml m-ditrifluorotoluene into a 50ml flask, add 1.01g (10mmol) triethylamine and mix well, then add 0.9g (10mmol) acryloyl chloride dropwise under nitrogen atmosphere at 0℃. Continue stirring for 5h, and stop the reaction after monitoring the reaction by TLC. Then remove the low boiling point by vacuum distillation, purify by silica gel and dilute to obtain 20%wt perfluoropolyether acrylate compound PFPE-4. Its structure is as follows:

[0039] Comparative Example 2 Add 0.67g (3mmol) of isophorone diisocyanate, 8g of m-ditrifluorotoluene solvent and 0.16g of dibutyltin dilaurate to the reaction bottle and stir evenly. Subsequently, weigh 3g of perfluoropolyether alcohol (Mn=1000g / mol, 3mmol) and dissolve it in 8g of m-ditrifluorotoluene. Slowly add it to the reaction bottle through a constant pressure separatory funnel under a nitrogen atmosphere. After the addition is completed, heat it to 50°C and continue the reaction. After the -OH group reacts completely as determined by infrared spectroscopy, continue to add 0.35g (3mmol) of hydroxyethyl acrylate to the reaction bottle. After the -NCO group peak is determined by infrared spectroscopy, stop the reaction to obtain a 20%wt perfluoropolyether acrylate compound PFPE-5, the structure of which is as follows: .

[0040] Comparative Example 3 Add 0.67g (3mmol) of isophorone diisocyanate, 8g of m-ditrifluorotoluene solvent and 0.16g of dibutyltin dilaurate to the reaction bottle and stir evenly. Subsequently, weigh 3g of perfluoropolyether alcohol (Mn=1000g / mol, 3mmol) and dissolve it in 7.5g of m-ditrifluorotoluene. Slowly add it to the reaction bottle through a constant pressure separatory funnel under a nitrogen atmosphere. After the addition is completed, heat it to 50°C and continue the reaction. After the -OH group is completely reacted by infrared spectroscopy, continue to add 0.9g (3mmol) of pentaerythritol triacrylate to the reaction bottle. After the -NCO group peak is determined by infrared spectroscopy, stop the reaction to obtain a 20%wt perfluoropolyether acrylate compound PFPE-6, the structure of which is as follows: .

[0041] The properties of the hard coating films and low reflection films prepared in the above Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 1 below.

[0042] (1) Contact angle test: The contact angle of the surface treatment layer to water and the contact angle of n-hexadecane were measured using a contact angle meter (XHS-CAZ1, Shenzhen Xinhengsen Instrument Equipment Co., Ltd.).

[0043] (2) Wear resistance test: A multifunctional wear tester (HG-9600, Dongguan Huaguo Precision Instrument Co., Ltd.) was used to evaluate the water contact angle of the surface treatment layer after friction under the following conditions: Steel wool: BONSTAR#0000; Load: 1kg / cm 2 The coating surface was rubbed at a cycle speed of 25 times / min, a friction length of 2.5 cm, and a friction number of 1000 times.

[0044] (3) Antifouling property of coating: Use an oily black marker to draw lines on the coating surface, wipe it with a dry paper towel, and observe whether there are stains on the surface. Grade and mark according to the following standards: Level 1: Indicates that the stain can be easily wiped off and there is no residue inside the paint film; Level 2: It means that the stain can be wiped off, but it is more laborious, and there is no residue inside the paint film; Level 3: The stain can be wiped off, but there are ink marks that have penetrated into the paint film; Level 4: Indicates that the stain cannot be wiped off.

[0045] Table 1 Properties of the films formed after curing of Examples 1 to 3 and Comparative Examples 1 to 2

[0046] Table 1 shows that, by comparing Examples 1-4 with Comparative Example 4, the PFPE segments can significantly improve the antifouling and wear resistance of the coating; compared with Comparative Examples 1-3, after the polysiloxane segments are introduced into PFPE, it has a higher compatibility with the coating system, and after curing, the perfluoropolyether segments migrate more thoroughly, greatly improving the antifouling performance of the coating. The above results show that the perfluoropolyether modified acrylate compound of the present invention can provide excellent waterproof, oil-proof and abrasion-resistant properties for the coating after curing as an antifouling additive.

[0047] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A method for preparing a perfluoropolyether modified acrylate compound, characterized in that: The synthesis method is as follows: Step 1: Add diisocyanate, a certain amount of catalyst and solvent into a reactor, dropwise add perfluoropolyether alcohol into the reactor under the protection of an inert atmosphere, raise the temperature to 30-70° C., react for 1-12 hours, and obtain an intermediate product 1; Step 2: Mix methyltriethoxysilane and diisopropanolamine, add p-toluenesulfonic acid to carry out a catalytic reaction, and obtain a hydroxyl-terminated hyperbranched polymerization intermediate product 2 containing a siloxane structure; Step 3: adding the intermediate product 1 to the product 2, heating and reacting for a period of time, adding an isocyanate-containing acrylate compound and continuing the reaction for a period of time to obtain a perfluoropolyether-modified acrylate compound.

2. The method for preparing a perfluoropolyether modified acrylate compound according to claim 1, characterized in that: The diisocyanate in step 1 includes at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate.

3. The method for preparing a perfluoropolyether modified acrylate compound according to claim 1, characterized in that: The catalyst in step 1 is a metal organic catalyst such as organic tin or organic titanium, and the perfluoropolyether alcohol is one of Z-type, K-type, Y-type, and D-type alcohol, with a molecular weight of 500 to 20,000.

4. The method for preparing a perfluoropolyether modified acrylate compound according to claim 1, characterized in that: The solvent in step 1 includes at least one of perfluorohexane, perfluoromethylcyclohexane, perfluoro-1, 3-dimethylcyclohexane, bis(trifluoromethyl)benzene, 3,3-pentafluorobutane, HCFC-225, perfluoropropyl methyl ether, perfluorobutyl methyl ether, perfluorobutyl ethyl ether, perfluorohexyl methyl ether or CF3CH2OCF2CHF2.

5. The method for preparing a perfluoropolyether modified acrylate compound according to claim 1, characterized in that: In step 1, the molar ratio of diisocyanate to perfluoropolyether alcohol is 1-1.5:1; and the inert atmosphere is a nitrogen atmosphere and / or a rare gas atmosphere.

6. The method for preparing a perfluoropolyether modified acrylate compound according to claim 1, characterized in that: The molar ratio of methyltriethoxysilane to diisopropanolamine in step 2 is 1:3-10; the total amount of p-toluenesulfonic acid added is 0.1-0.5wt% of the total mass of methyltriethoxysilane and diisopropanolamine.

7. The method for preparing a perfluoropolyether modified acrylate compound according to claim 1, characterized in that: The conditions of the catalytic reaction in step 2 are: heating at 60-150° C. for 1-2 h under nitrogen protection; then stopping the introduction of nitrogen and performing reduced pressure distillation at 60-150° C. for 1-2 h.

8. The method for preparing a perfluoropolyether modified acrylate compound according to claim 1, characterized in that: In step 3, the molar ratio of the intermediate product 1 to the product 2 is 1:0.5-2; the molar ratio of the isocyanate-containing acrylate compound to the product 2 is 1:0.5-1; the isocyanate-containing acrylate compound is selected from isocyanoethyl methacrylate IEM and isocyanate ethyl acrylate AOI.

9. The method for preparing a perfluoropolyether modified acrylate compound according to claim 1, characterized in that: In the step 3, the reaction temperature is 30-100° C., and the reaction time is 1-12 h.

10. Use of the perfluoropolyether modified acrylate compound prepared by the method according to any one of claims 1 to 9 as an auxiliary agent in photocurable paints and coatings.

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