Fluorine-containing super-hydrophobic coating and preparation process thereof

Abstract

The invention discloses a fluorine-containing super-hydrophobic coating and a preparation process thereof, and relates to the technical field of hydrophobic coatings. The fluorine-containing super-hydrophobic coating is prepared from the following components in parts by mass: 60 to 80 parts of composite fluorine-containing resin, 5 to 15 parts of filler and 5 to 10 parts of curing agent, the composite fluorine-containing resin is obtained by blending epoxy resin and a fluorine-containing esterified epoxy compound. The preparation method comprises the following steps: blending epoxy resin and a fluorine-containing esterified epoxy compound to obtain composite fluorine-containing resin; the low surface energy of a fluorine-containing esterified epoxy compound and the good adhesiveness of epoxy resin are utilized, in the coating curing process, fluorine chain segments migrate to the surface of a coating, the surface energy of the coating is reduced, the epoxy resin is subjected to a cross-linking reaction under the action of a curing agent, and the problem that the adhesive force of the coating is poor is solved; after curing, a tighter and firmer three-dimensional network structure is formed, the cross-linking strength of the coating is improved, and the hydrophobicity and cracking resistance of the coating are comprehensively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrophobic coatings, and in particular to a fluorine-containing super hydrophobic coating and a preparation process thereof. Background Art

[0002] The inspiration for the development of hydrophobic coatings originated from the "lotus effect". The micro-nano structure on the surface of lotus leaves enables it to self-clean, and the pollutants on the surface are carried away by the rolling of water droplets. Through this phenomenon, the hydrophobic coating was developed by imitating the surface structure of lotus leaves. The technical principle is to reduce the surface energy of the coating by constructing a microstructure or introducing low surface energy substances such as silicon and fluorine into the raw materials, making it difficult for water droplets to wet the surface, thus achieving the purpose of hydrophobicity.

[0003] Chinese patent CN105602411A discloses a fluorine-containing hydrophobic coating material and a preparation method thereof, comprising the following components: epoxy resin, dendritic fluorine-containing curing agent, other curing agents, solvent, and silane coupling agent; the method has a low curing temperature and a short curing time, but the physical properties of the coating are not mentioned.

[0004] Therefore, we propose a fluorine-containing super-hydrophobic coating and its preparation process to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a fluorine-containing super-hydrophobic coating and a preparation process thereof to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solution: a fluorine-containing super-hydrophobic coating, comprising the following components by mass: 60-80 parts of a composite fluorine-containing resin, 5-15 parts of a filler, and 5-10 parts of a curing agent.

[0007] Furthermore, the composite fluorine-containing resin is obtained by blending an epoxy resin with a fluorine-containing esterified epoxy compound;

[0008] The filler is obtained by surface modification of the filler by a coupling agent;

[0009] The filler is SiO2 (silicon dioxide).

[0010] Furthermore, the coupling agent is obtained by reacting cardanol with γ-glycidyloxypropyltrimethoxysilane.

[0011] Further, epoxy resin: brand E44, epoxy equivalent 210-230 g / mol, sourced from Jiangyin Wanqian Chemicals Co., Ltd.;

[0012] SiO2, item number: 104014, 200-300nm, sourced from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.

[0013] A preparation process of a fluorine-containing super-hydrophobic coating comprises the following steps:

[0014] The composite fluorine-containing resin, filler and curing agent are mixed and stirred for 0.5-2 hours to obtain a fluorine-containing hydrophobic adhesive. The adhesive is applied to a substrate, dried and cured to obtain a fluorine-containing super-hydrophobic coating.

[0015] Furthermore, the mass ratio of the composite fluorine-containing resin, filler and curing agent is (60-80):(5-15):(5-10).

[0016] Furthermore, the drying process conditions are: temperature 60-70°C, time 1-2h;

[0017] The curing process conditions are: temperature 130-180°C, insulation 2-3h, pressure 0.5-1MPa.

[0018] Furthermore, the curing agent is a mixture of one or more of ethylenediamine, phthalic anhydride and meta-phenylenediamine.

[0019] Furthermore, the composite fluorine-containing resin is prepared by the following process:

[0020] Step 1: xylene, 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-benzenedicarboxylic acid), 1H,1H,12H,12H-perfluoro-1,12-dodecanediol and concentrated sulfuric acid are mixed, heated for reaction under the protection of nitrogen atmosphere, and distilled under reduced pressure after the reaction is completed to obtain a polyhydroxy compound A;

[0021] Step 2: Mix polyhydroxy compound A, acrylic acid and concentrated sulfuric acid, and heat to react under nitrogen atmosphere to obtain compound B;

[0022] Step 3: Compound B, toluene and glacial acetic acid are mixed, magnetically stirred at room temperature, heated to 50-60°C, hydrogen peroxide is added dropwise, reacted at a constant temperature for 4-6 hours, cooled, and washed to obtain a fluorinated esterified epoxy compound C;

[0023] Step 4: Mix the fluorinated esterified epoxy compound C with the epoxy resin, stir evenly, and obtain a composite fluorinated resin.

[0024] Furthermore, in step 1, the molar ratio of xylene, 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-phthalic acid), 1H,1H,12H,12H-perfluoro-1,12-dodecanediol, and concentrated sulfuric acid is (8-16):1:(4.5-6.5):(0.01-0.03).

[0025] Furthermore, the heating reaction conditions in step 1 are: temperature 130-180° C., time 3-5 h.

[0026] Furthermore, in step 2, the molar ratio of polyhydroxy compound A, acrylic acid and concentrated sulfuric acid is (1-3): (4-12): (0.01-0.03).

[0027] Furthermore, the heating reaction conditions in step 2 are: temperature 130-180° C., time 3-5 h.

[0028] Furthermore, in step 3, the mass ratio of compound B, toluene, glacial acetic acid and hydrogen peroxide is 1:(1-3):(0.1-0.3):(0.7-1.2).

[0029] Furthermore, the rotation speed of the magnetic stirring in step 3 is: 50-70r / min.

[0030] Furthermore, in step 3, the dropping speed is 2-3 drops / s.

[0031] Furthermore, in step 4, the mass ratio of the fluorinated esterified epoxy compound C to the epoxy resin is (1-3):10.

[0032] Further, xylene, CAS No. 1330-20-7, was sourced from Shanghai Xiangheyi Chemical Technology Co., Ltd.;

[0033] 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-benzenedicarboxylic acid), CAS No. 3016-76-0, from Gaide Chemicals;

[0034] 1H,1H,12H,12H-Perfluoro-1,12-dodecanediol, CAS No. 183162-43-8, from Gaide Chemicals;

[0035] Acrylic acid, CAS No. 79-10-7, from Langcheng Chemical;

[0036] Concentrated sulfuric acid, CAS No. 7664-93-9, from Merck Reagent;

[0037] Toluene, CAS No. 108-88-3, from Merck Reagent;

[0038] Glacial acetic acid, CAS No. 64-19-7, from Jinan Zesheng Chemical Co., Ltd.;

[0039] Hydrogen peroxide, CAS No. 7722-84-1, concentration 30%, was obtained from Merck Reagent.

[0040] In the above technical scheme, the carboxyl group of 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-phthalic acid) is esterified with the hydroxyl group of 1H,1H,12H,12H-perfluoro-1,12-dodecanediol to generate a polyhydroxy compound A, which is then esterified with acrylic acid to obtain a compound B, and the double bonds in the compound B are epoxidized to obtain a fluorine-containing esterified epoxy compound C, which is then blended with an epoxy resin to obtain a composite fluorine-containing resin; the low surface energy and ring energy of the fluorine-containing esterified epoxy compound C are utilized to obtain a composite fluorine-containing resin. Epoxy resin has good adhesion. During the curing process of the coating, the fluorine chain segments migrate to the surface of the coating, reducing the surface energy of the coating. The epoxy resin undergoes a cross-linking reaction under the action of the curing agent, solving the problem of poor adhesion of the coating. Through esterification and epoxidation reactions, a cross-linking structure is formed, which enhances the strength, hardness and heat resistance of the epoxy esterified compound. The epoxy esterified compound is then blended with the epoxy resin. After the coating is cured, a tighter and stronger three-dimensional network structure is formed, thereby increasing the cross-linking strength of the coating, and comprehensively improving the hydrophobicity and anti-cracking properties of the coating.

[0041] Furthermore, the filler is surface modified, and the specific process is as follows:

[0042] Mix SiO2 and anhydrous ethanol, stir evenly to form a SiO2 ethanol suspension, heat the suspension in a water bath, add ammonia water, stir and react for 25-45 minutes, then add a coupling agent, continue stirring and reacting for 18-22 hours, wash the reaction product 2-4 times, and dry to obtain a modified filler.

[0043] Furthermore, the ratio of SiO2, anhydrous ethanol, ammonia water and coupling agent is (1.5-2.5) g: (30-50) mL: (3-5) mL: (4-6) mL.

[0044] Furthermore, the process conditions of water bath heating are: temperature 50-60°C, time 20-30min.

[0045] Furthermore, the rotation speed of the stirring reaction is: 60-100r / min.

[0046] Furthermore, anhydrous ethanol, CAS number: 64-17-5, was obtained from Merck reagent;

[0047] Ammonia, CAS number: 1336-21-6, was obtained from Nanjing Shengqinghe Chemical Co., Ltd.

[0048] Further, the coupling agent is prepared by the following process:

[0049] Mix γ-glycidyloxypropyltrimethoxysilane and xylene to obtain a mixed solution, heat it to 80-100° C., add cardanol and an initiator under the protection of a nitrogen atmosphere, stir evenly, and keep the mixture warm for 1-2 hours to obtain a coupling agent.

[0050] Further, the mass ratio of γ-glycidyloxypropyltrimethoxysilane to the solvent is 1:(1.5-2.5);

[0051] The mass ratio of the mixed solution, cardanol and initiator is (8-12):(2-4):(0.05-0.1).

[0052] Furthermore, the initiator is azobisisovaleronitrile, CAS No.: 13472-08-7, sourced from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.;

[0053] γ-Glycidyloxypropyltrimethoxysilane, CAS No.: 2530-83-8, from Hangzhou Jessica Chemical Co., Ltd.;

[0054] Cardanol, CAS number: 501-24-6, comes from Shandong Yingsheng Chemical Co., Ltd.

[0055] In the above technical scheme, γ-glycidyloxypropyltrimethoxysilane is modified by cardanol, phenolic hydroxyl groups are introduced to obtain a coupling agent containing phenolic hydroxyl groups, and then SiO2 is modified to obtain a modified filler; the phenolic hydroxyl groups in cardanol react with the epoxy groups in γ-glycidyloxypropyltrimethoxysilane to form stable chemical bonds, thereby enhancing the interaction between molecules, promoting the formation of a three-dimensional network structure, and improving the adhesion performance at the interface between the filler and the epoxy resin, giving the coating excellent toughness and strength, making the coating less likely to crack, and enhancing the mechanical properties of the coating.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] 1. The carboxyl group of 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-phthalic acid) undergoes esterification reaction with the hydroxyl group of 1H,1H,12H,12H-perfluoro-1,12-dodecanediol to generate a polyhydroxy compound A, which is then esterified with acrylic acid to obtain a compound B, and the double bonds in the compound B are epoxidized to obtain a fluorinated esterified epoxy compound C, which is then blended with an epoxy resin to obtain a composite fluorinated resin; the low surface energy of the fluorinated esterified epoxy compound C and the good performance of the epoxy resin are utilized to obtain a composite fluorinated resin. Good adhesion. During the curing process of the coating, the fluorine chain segments migrate to the surface of the coating, reducing the surface energy of the coating. The epoxy resin undergoes a cross-linking reaction under the action of the curing agent, solving the problem of poor adhesion of the coating. Through esterification and epoxidation reactions, a cross-linking structure is formed, which enhances the strength, hardness and heat resistance of the epoxy esterified compound. The epoxy esterified compound is then blended with the epoxy resin. After the coating is cured, a tighter and stronger three-dimensional network structure is formed, thereby increasing the cross-linking strength of the coating, and comprehensively improving the hydrophobicity and anti-cracking properties of the coating.

[0058] 2. γ-glycidyloxypropyltrimethoxysilane is modified by cardanol, phenolic hydroxyl groups are introduced, and a coupling agent containing phenolic hydroxyl groups is obtained. Then SiO2 is modified to obtain a modified filler. The phenolic hydroxyl groups in cardanol undergo a ring-opening reaction with the epoxy groups in γ-glycidyloxypropyltrimethoxysilane to form stable chemical bonds, thereby enhancing the interaction between molecules, promoting the formation of a three-dimensional network structure, and improving the adhesion performance at the interface between the filler and the epoxy resin, giving the coating excellent toughness and strength, making the coating less likely to crack, and enhancing the mechanical properties of the coating. DETAILED DESCRIPTION

[0059] 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.

[0060] In the following specific implementations,

[0061] Epoxy resin: brand E44, epoxy equivalent 210-230g / mol, from Jiangyin Wanqian Chemicals Co., Ltd.

[0062] SiO2, item number: 104014, 200-300nm, from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.;

[0063] Xylene, CAS No. 1330-20-7, from Shanghai Xiangheyi Chemical Technology Co., Ltd.;

[0064] 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-benzenedicarboxylic acid), CAS No. 3016-76-0, from Gaide Chemicals;

[0065] 1H,1H,12H,12H-Perfluoro-1,12-dodecanediol, CAS No. 183162-43-8, from Gaide Chemicals;

[0066] Acrylic acid, CAS No. 79-10-7, from Langcheng Chemical;

[0067] Concentrated sulfuric acid, CAS No. 7664-93-9, from Merck Reagent;

[0068] Toluene, CAS No. 108-88-3, from Merck Reagent;

[0069] Glacial acetic acid, CAS No. 64-19-7, from Jinan Zesheng Chemical Co., Ltd.;

[0070] Hydrogen peroxide, CAS No. 7722-84-1, concentration 30%, from Merck Reagent;

[0071] Anhydrous ethanol, CAS number: 64-17-5, from Merck reagent;

[0072] Ammonia, CAS No.: 1336-21-6, from Nanjing Shengqinghe Chemical Co., Ltd.;

[0073] The initiator was azobisisovaleronitrile, CAS No. 13472-08-7, from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.;

[0074] γ-Glycidyloxypropyltrimethoxysilane, CAS No.: 2530-83-8, from Hangzhou Jessica Chemical Co., Ltd.;

[0075] Cardanol, CAS No.: 501-24-6, from Shandong Yingsheng Chemical Co., Ltd.;

[0076] The curing agent is ethylenediamine, CAS number: 107-15-3, from Merck reagent;

[0077] 1,12-Dodecanediol, CAS No.: 5675-51-4, from Nanjing Reagent;

[0078] 3,3'4,4'-Biphenyltetracarboxylic acid, CAS No.: 22803-05-0, derived from MacLean reagent;

[0079] 1,4-Bis(2',3'-epoxypropyl)perfluorobutane, CAS No.: from Shanghai Yuanye Biotechnology Co., Ltd.

[0080] Embodiment 1: A process for preparing a fluorine-containing super-hydrophobic coating, comprising the following steps:

[0081] (1) Preparation of composite fluorine-containing resin:

[0082] Step 1: xylene, 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-phthalic acid), 1H,1H,12H,12H-perfluoro-1,12-dodecanediol and concentrated sulfuric acid are mixed, heated under a nitrogen atmosphere for reaction, and distilled under reduced pressure after the reaction is completed to obtain a polyhydroxy compound A; Step 2: polyhydroxy compound A, acrylic acid and concentrated sulfuric acid are mixed, heated under a nitrogen atmosphere for reaction, and compound B is obtained after the reaction is completed; Step 3: compound B, toluene and glacial acetic acid are mixed, magnetically stirred at room temperature, heated to 50°C, hydrogen peroxide is added dropwise, the reaction is carried out at a constant temperature for 4h, cooled, and washed to obtain a fluorine-containing esterified epoxy compound C; Step 4: fluorine-containing esterified epoxy compound C is mixed with epoxy resin, stirred evenly, and a composite fluorine-containing resin is obtained; in step 1 The molar ratio of xylene, 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-phthalic acid), 1H,1H,12H,12H-perfluoro-1,12-dodecanediol and concentrated sulfuric acid is 8:1:4.5:0.01; the conditions for the heating reaction in step 1 are: temperature 130°C, time 3h; the molar ratio of polyhydroxy compound A, acrylic acid and concentrated sulfuric acid in step 2 is 1:4:0.01; the conditions for the heating reaction in step 2 are: temperature 130°C, time 3h; the mass ratio of compound B, toluene, glacial acetic acid and hydrogen peroxide in step 3 is 1:1:0.1:0.7; the speed of magnetic stirring in step 3 is: 50r / min; the droplet addition speed in step 3 is 2 drops / s; in step 4, the mass ratio of fluorinated esterified epoxy compound C and epoxy resin is 1:10;

[0083] (2) Preparation of modified filler:

[0084] γ-glycidyloxypropyltrimethoxysilane and xylene are mixed to obtain a mixed solution, which is heated to 80°C. Cardanol and an initiator are added under nitrogen atmosphere and stirred evenly. The mixture is kept warm for 1 hour to obtain a coupling agent. The mass ratio of γ-glycidyloxypropyltrimethoxysilane to the solvent is 1:1.5; the mass ratio of the mixed solution, cardanol, hexafluorobutyl methacrylate, and the initiator is 8:2:0.05.

[0085] Mix SiO2 and anhydrous ethanol, stir evenly to form SiO2 ethanol suspension, heat the suspension in a water bath, add ammonia water, stir and react for 25 minutes, then add coupling agent, continue stirring and react for 18 hours, wash the reaction product twice, dry and obtain modified filler; the ratio of SiO2, anhydrous ethanol, ammonia water and coupling agent is 1.5g:30mL:3mL:4mL; the process conditions of water bath heating are: temperature 50℃, time 20min; the speed of stirring reaction is: 60r / min;

[0086] (3) Preparation of fluorine-containing super-hydrophobic coating:

[0087] The composite fluorine-containing resin, modified filler and curing agent are mixed in a mass ratio of 60:5:5, stirred for 0.5h to obtain a fluorine-containing hydrophobic adhesive, and the adhesive is applied to a substrate, dried, and cured to obtain a fluorine-containing super-hydrophobic coating; the drying process conditions are: temperature 60°C, time 1h; the curing process conditions are: temperature 130°C, insulation 2h, pressure 0.5MPa.

[0088] Embodiment 2: A process for preparing a fluorine-containing super-hydrophobic coating, comprising the following steps:

[0089] (1) Preparation of composite fluorine-containing resin:

[0090] Step 1: xylene, 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-phthalic acid), 1H,1H,12H,12H-perfluoro-1,12-dodecanediol and concentrated sulfuric acid are mixed, heated under a nitrogen atmosphere for reaction, and distilled under reduced pressure after the reaction is completed to obtain a polyhydroxy compound A; Step 2: polyhydroxy compound A, acrylic acid and concentrated sulfuric acid are mixed, heated under a nitrogen atmosphere for reaction, and compound B is obtained after the reaction is completed; Step 3: compound B, toluene and glacial acetic acid are mixed, magnetically stirred at room temperature, heated to 55°C, hydrogen peroxide is added dropwise, the reaction is carried out at a constant temperature for 5h, cooled, and washed to obtain a fluorinated esterified epoxy compound C; Step 4: fluorinated esterified epoxy compound C is mixed with epoxy resin, stirred evenly to obtain a composite fluorinated resin; the two in step 1 The molar ratio of toluene, 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-phthalic acid), 1H,1H,12H,12H-perfluoro-1,12-dodecanediol and concentrated sulfuric acid is 12:1:5.5:0.02; the conditions for the heating reaction in step 1 are: temperature 150°C, time 4h; the molar ratio of polyhydroxy compound A, acrylic acid and concentrated sulfuric acid in step 2 is 2:8:0.02; the conditions for the heating reaction in step 2 are: temperature 150°C, time 4h; the mass ratio of compound B, toluene, glacial acetic acid and hydrogen peroxide in step 3 is 1:2:0.2:1.0; the speed of magnetic stirring in step 3 is: 60r / min; the droplet addition speed in step 3 is 2 drops / s; in step 4, the mass ratio of fluorinated esterified epoxy compound C and epoxy resin is 2:10;

[0091] (2) Preparation of modified filler:

[0092] γ-glycidyloxypropyltrimethoxysilane and xylene are mixed to obtain a mixed solution, which is heated to 90°C. Cardanol and an initiator are added under nitrogen atmosphere and stirred evenly. The mixture is kept warm for 1.5 hours to obtain a coupling agent. The mass ratio of γ-glycidyloxypropyltrimethoxysilane to the solvent is 1:2; the mass ratio of the mixed solution to cardanol to the initiator is 10:3:0.08.

[0093] Mix SiO2 and anhydrous ethanol, stir evenly to form SiO2 ethanol suspension, heat the suspension in a water bath, add ammonia water, stir and react for 30 minutes, then add coupling agent, continue stirring and react for 20 hours, wash the reaction product 3 times, dry and obtain modified filler; the ratio of SiO2, anhydrous ethanol, ammonia water and coupling agent is 2g:40mL:4mL:5mL; the process conditions of water bath heating are: temperature 70℃, time 25min; the speed of stirring reaction is: 80r / min;

[0094] (3) Preparation of fluorine-containing super-hydrophobic coating:

[0095] The composite fluorine-containing resin, modified filler and curing agent are mixed in a mass ratio of 70:10:8, stirred for 1.5 hours to obtain a fluorine-containing hydrophobic adhesive, and the adhesive is applied to a substrate, dried, and cured to obtain a fluorine-containing super-hydrophobic coating; the drying process conditions are: temperature 65°C, time 1.5 hours; the curing process conditions are: temperature 150°C, insulation 2.5 hours, pressure 0.7MPa.

[0096] Embodiment 3: A process for preparing a fluorine-containing super-hydrophobic coating, comprising the following steps:

[0097] (1) Preparation of composite fluorine-containing resin:

[0098] Step 1: Mix xylene, 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-phthalic acid), 1H,1H,12H,12H-perfluoro-1,12-dodecanediol and concentrated sulfuric acid, heat to react under nitrogen atmosphere, and perform reduced pressure distillation after the reaction to obtain polyhydroxy compound A; Step 2: Mix polyhydroxy compound A, acrylic acid and concentrated sulfuric acid, heat to react under nitrogen atmosphere, and perform compound B after the reaction; Step 3: Mix compound B, toluene and glacial acetic acid, stir magnetically at room temperature, heat to 60°C, add hydrogen peroxide dropwise, react at constant temperature for 6h, cool, and wash to obtain fluorine-containing esterified epoxy compound C; Step 4: Mix fluorine-containing esterified epoxy compound C with epoxy resin, stir evenly to obtain composite fluorine-containing resin; The molar ratio of toluene, 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-phthalic acid), 1H,1H,12H,12H-perfluoro-1,12-dodecanediol and concentrated sulfuric acid is 16:1:6.5:0.03; the conditions for the heating reaction in step 1 are: temperature 180°C, time 5h; the molar ratio of polyhydroxy compound A, acrylic acid and concentrated sulfuric acid in step 2 is 3:12:0.03; the conditions for the heating reaction in step 2 are: temperature 180°C, time 5h; the mass ratio of compound B, toluene, glacial acetic acid and hydrogen peroxide in step 3 is 1:3:0.3:1.2; the speed of magnetic stirring in step 3 is: 70r / min; the droplet addition speed in step 3 is 3 drops / s; in step 4, the mass ratio of fluorinated esterified epoxy compound C and epoxy resin is 3:10;

[0099] (2) Preparation of modified filler:

[0100] γ-glycidyloxypropyltrimethoxysilane and xylene are mixed to obtain a mixed solution, which is heated to 100°C. Under the protection of a nitrogen atmosphere, cardanol and an initiator are added and stirred evenly. The mixture is kept warm for 2 hours to obtain a coupling agent. The mass ratio of γ-glycidyloxypropyltrimethoxysilane to the solvent is 1:2.5; the mass ratio of the mixed solution to cardanol to the initiator is 12:4:0.1.

[0101] Mix SiO2 and anhydrous ethanol, stir evenly to form SiO2 ethanol suspension, heat the suspension in a water bath, add ammonia water, stir and react for 45 minutes, then add coupling agent, continue stirring and react for 22 hours, wash the reaction product 4 times, dry and obtain modified filler; the ratio of SiO2, anhydrous ethanol, ammonia water and coupling agent is 2.5g:50mL:5mL:6mL; the process conditions of water bath heating are: temperature 60℃, time 30min; the speed of stirring reaction is: 100r / min;

[0102] (3) Preparation of fluorine-containing super-hydrophobic coating:

[0103] The composite fluorine-containing resin, modified filler and curing agent are mixed in a mass ratio of 80:15:10, stirred for 2 hours, and a fluorine-containing hydrophobic adhesive is obtained. The adhesive is applied to a substrate, dried, and cured to obtain a fluorine-containing super-hydrophobic coating. The drying process conditions are: temperature 70°C, time 2 hours; the curing process conditions are: temperature 180°C, insulation 3 hours, pressure 1MPa.

[0104] Comparative Example 1: Using Example 1 as a comparison, 1H,1H,12H,12H-perfluoro-1,12-dodecanediol was replaced by 1,12-dodecanediol, and 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-phthalic acid) was replaced by 3,3'4,4'-biphenyltetracarboxylic acid, and the other conditions remained unchanged;

[0105] Comparative Example 2: Using Example 1 as a comparison, the fluorinated esterified epoxy compound C was replaced with 1,4-di(2',3'-epoxypropyl)perfluorobutane, and the other conditions remained unchanged;

[0106] Comparative Example 3: Using Example 1 as a comparison, the fluorinated esterified epoxy compound C is replaced with 1,4-di(2',3'-epoxypropyl)perfluorobutane, and the filler is not modified, while the other conditions remain unchanged;

[0107] Comparative Example 4: Using Example 1 as a comparison, the filler is not modified, the fluorinated esterified epoxy compound C is not added, and the other conditions remain unchanged. The specific steps are as follows:

[0108] Epoxy resin, filler and curing agent are mixed in a mass ratio of 60:5:5, stirred for 0.5h to obtain a rubber compound, which is applied to a substrate, dried, and cured to obtain a coating; the drying process conditions are: temperature 60°C, time 1h; the curing process conditions are: temperature 130°C, insulation 2h, pressure 0.5MPa.

[0109] Experiment: The hydrophobic coatings obtained in Examples 1-3 and Comparative Examples 1-3 were prepared into samples, and their performance was tested and the results were recorded;

[0110] Hydrophobic performance test: 6 μL of deionized water was added to the sample surface, and the water droplet profile was fitted using the circular fitting method to perform contact angle analysis;

[0111] Add 8 μL of deionized water on the surface of the sample, adjust the rotating platform until the deionized water rolls off, the tilt angle of the platform is the rolling angle, take the average of 3 measurements and record it in the table below;

[0112] Adhesion test: According to GB / T9286-1998, the adhesion test was carried out, and the test results are shown in the following table;

[0113] Tensile performance test: The tensile performance test was carried out using an electronic universal material testing machine at 25°C and a tensile rate of 300 mm / min;

[0114] The following table shows the test results of contact angle, rolling angle, adhesion and tensile strength of the hydrophobic coating;

[0115] Contact angle / ° Roll angle / ° Adhesion Tensile strength / MPa Example 1 148.2 4.2 Level 1 22.3 Example 2 158.8 3.7 Level 0 27.1 Example 3 166.1 3.3 Level 0 32.9 Comparative Example 1 135.5 4.9 Level 1 21.1 Comparative Example 2 140.7 4.7 Level 1 19.8 Comparative Example 3 136.6 5.6 Level 2 16.8 Comparative Example 4 127.8 6.2 Level 3 14.5

[0116] According to the data in the above table, we can clearly draw the following conclusions:

[0117] The coatings obtained in Examples 1-3 are compared with the coatings obtained in Comparative Examples 1-3. The test results show that:

[0118] Compared with Example 1, the hydrophobic performance of Comparative Example 1 is reduced because 1,12-dodecanediol does not contain a hydrophobic fluorine segment, and therefore the synthesized esterified epoxy compound does not contain a fluorine segment, which cannot reduce the surface energy of the coating, resulting in a decrease in the hydrophobic ability of the coating;

[0119] Compared with Example 1, the tensile strength of Comparative Example 2 is reduced. The fluorinated esterified epoxy compound C is replaced with 1,4-bis(2',3'-epoxypropyl)perfluorobutane. 1,4-bis(2',3'-epoxypropyl)perfluorobutane contains a longer perfluorocarbon chain, which produces a larger steric hindrance effect, resulting in a low degree of crosslinking with the epoxy resin, resulting in a decrease in the tensile strength of the coating;

[0120] Compared with Example 1, the adhesion and tensile strength of Comparative Example 3 decreased significantly because the filler was not modified, the adhesion performance at the interface between the filler and the epoxy resin decreased, the toughness of the coating decreased, and it was easy to crack, resulting in a decrease in the tensile performance of the coating;

[0121] Compared with Example 1, in Comparative Example 4, the filler is not modified and the fluorinated esterified epoxy compound C is not added. All properties are significantly reduced, indicating that the preparation process of the coating and the setting of the components used in the present invention can promote the comprehensive improvement of its hydrophobicity and mechanical properties.

[0122] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A fluorine-containing super-hydrophobic coating, characterized in that: It includes the following mass components: 60-80 parts of composite fluorine-containing resin, 5-15 parts of filler, and 5-10 parts of curing agent; The composite fluorine-containing resin is obtained by blending epoxy resin with a fluorine-containing esterified epoxy compound.

2. A fluorine-containing super-hydrophobic coating according to claim 1, characterized in that: The filler is obtained by surface modification of the filler by a coupling agent; The filler is SiO2.

3. A fluorine-containing super-hydrophobic coating according to claim 2, characterized in that: The coupling agent is obtained by reacting cardanol with gamma-glycidyloxypropyltrimethoxysilane.

4. A preparation process of a fluorine-containing super-hydrophobic coating, characterized in that: The following steps are involved: The composite fluorine-containing resin, filler and curing agent are mixed and stirred for 0.5-2 hours to obtain a fluorine-containing hydrophobic adhesive. The adhesive is applied to a substrate, dried and cured to obtain a fluorine-containing super-hydrophobic coating.

5. A process for preparing a fluorine-containing super-hydrophobic coating according to claim 4, characterized in that: The composite fluorine-containing resin is prepared by the following process: Step 1: xylene, 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-benzenedicarboxylic acid), 1H,1H,12H,12H-perfluoro-1,12-dodecanediol and concentrated sulfuric acid are mixed, heated for reaction under the protection of nitrogen atmosphere, and distilled under reduced pressure after the reaction is completed to obtain a polyhydroxy compound A; Step 2: Mix polyhydroxy compound A, acrylic acid and concentrated sulfuric acid, and heat to react under nitrogen atmosphere to obtain compound B; Step 3: Compound B, toluene and glacial acetic acid are mixed, magnetically stirred at room temperature, heated to 50-60°C, hydrogen peroxide is added dropwise, reacted at a constant temperature for 4-6 hours, cooled, and washed to obtain a fluorinated esterified epoxy compound C; Step 4: Mix the fluorinated esterified epoxy compound C with the epoxy resin, stir evenly, and obtain a composite fluorinated resin.

6. A process for preparing a fluorine-containing super-hydrophobic coating according to claim 5, characterized in that: In step 1, the molar ratio of xylene, 4,4'-(2,2,2-trifluoro-1-trifluoromethyl)ethylenebis(1,2-benzenedicarboxylic acid), 1H,1H,12H,12H-perfluoro-1,12-dodecanediol and concentrated sulfuric acid is (8-16):1:(4.5-6.5):(0.01-0.03).

7. A process for preparing a fluorine-containing super-hydrophobic coating according to claim 4, characterized in that: The filler is surface modified, and the specific process is as follows: Mix SiO2 and anhydrous ethanol, stir evenly to form a SiO2 ethanol suspension, heat the suspension in a water bath, add ammonia water, stir and react for 25-45 minutes, then add a coupling agent, continue stirring and reacting for 18-22 hours, wash the reaction product 2-4 times, and dry to obtain a modified filler.

8. A process for preparing a fluorine-containing super-hydrophobic coating according to claim 7, characterized in that: The coupling agent is prepared by the following process: Mix γ-glycidyloxypropyltrimethoxysilane and xylene to obtain a mixed solution, heat it to 80-100° C., add cardanol and an initiator under the protection of a nitrogen atmosphere, stir evenly, and keep the mixture warm for 1-2 hours to obtain a coupling agent.

9. A process for preparing a fluorine-containing super-hydrophobic coating according to claim 4, characterized in that: The drying process conditions are: temperature 60-70℃, time 1-2h; The curing process conditions are: temperature 130-180°C, insulation 2-3h, pressure 0.5-1MPa.

10. The process for preparing a fluorine-containing super-hydrophobic coating according to claim 5, characterized in that: In step 2, the molar ratio of polyhydroxy compound A, acrylic acid and concentrated sulfuric acid is (1-3): (4-12): (0.01-0.03).