High-hardness organosilicon anticorrosive paint and preparation method thereof

Abstract

The invention belongs to the technical field of anticorrosive coatings, and particularly relates to a high-hardness organosilicon anticorrosive coating and a preparation method thereof. Vinyltrimethoxysilane, gamma-glycidyl ether oxypropyl trimethoxysilane and diphenyl silanediol are used as raw materials to prepare epoxidized organic silicon resin, the epoxidized organic silicon resin is matched with polyamide resin, composite filler and titanium dioxide for common use, the high-hardness organic silicon anticorrosive coating is prepared, good hardness and wear resistance are guaranteed, and the coating has the advantages of being good in corrosion resistance, good in corrosion resistance, good in corrosion resistance and the like. And meanwhile, salt mist resistance and liquid medium resistance can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of anti-corrosion coatings, and particularly relates to a high-hardness silicone anti-corrosion coating and a preparation method thereof. Background Art

[0002] In the field of coatings, currently, the requirements for coating performance in civil, military and other fields are getting higher and higher. Coatings used in construction, marine, aerospace and other aspects need to have excellent high-temperature resistance, pollution resistance, anti-biofouling property, weather resistance and other characteristics. Due to its unique performance advantages and good stability, silicone polymer has been widely used as an important component in the research and development and application of new coatings. Silicone resin mainly has a silicon-oxygen bond as the backbone, and forms a complex and stable network structure by connecting silicon atoms with organic groups. This structure endows it with good heat resistance, chemical stability, excellent mechanical properties and electrical properties. Therefore, the coatings prepared with it as the film-forming substance can still maintain good stability in harsh environments with high temperature and high pressure and strong chemical corrosion.

[0003] The patent with the publication number CN111269650B discloses a silicone high-temperature resistant anti-corrosion coating and a preparation method thereof. In this invention, the crosslinking degree of the coating is effectively improved by introducing polyfunctional glycerol into the silicone resin, which not only provides the high-temperature resistance of the coating, but also improves the shielding property of the coating film. The introduction of trifluoroethanol can reduce the surface energy of the coating, thereby improving the waterproof and anti-fouling ability of the coating itself. The addition of high-temperature resistant fillers can further improve the high-temperature resistance of the coating. At the same time, the addition of flaky sericite powder in the fillers can be horizontally arranged in the coating, improving the shielding property and anti-permeability of the coating, and further improving the anti-corrosion performance of the coating. However, the hardness of the coating provided by this patented technology is relatively low, and its wear resistance also needs to be improved. The above problems affect its further extended use.

[0004] Therefore, how to modify silicone resin, introduce other functional components, and through the synergistic effect of multiple components, prepare a high-hardness silicone anti-corrosion coating, obtain good hardness and wear resistance, and at the same time be able to resist salt spray and liquid media has become the key direction to be overcome. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a high-hardness silicone anti-corrosion coating and a preparation method thereof. The present invention uses vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and diphenylsilanediol as raw materials to prepare an epoxy silicone resin, and cooperates with the common use of polyamide resin, composite filler and titanium dioxide to prepare a high-hardness silicone anti-corrosion coating, ensuring good hardness and wear resistance, and at the same time being able to resist salt spray and liquid media.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows: In the first aspect of the present invention, a high-hardness silicone anti-corrosion coating is provided. By weight, it comprises the following components: 40 - 50 parts of epoxy silicone resin, 40 - 60 parts of polyamide resin, 10 - 15 parts of filler, 6 - 10 parts of titanium dioxide, 2 - 4 parts of drier, and 70 - 90 parts of solvent.

[0007] As a preferred solution, the weight parts of the epoxy silicone resin in the present invention can be 40 parts, 42 parts, 44 parts, 46 parts, 48 parts, 50 parts, etc.

[0008] As a preferred solution, the weight parts of the polyamide resin in the present invention can be 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, etc.

[0009] As a preferred solution, the weight parts of the filler in the present invention can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, etc.

[0010] As a preferred solution, the weight parts of the titanium dioxide in the present invention can be 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.

[0011] As a preferred solution, the weight parts of the drier in the present invention can be 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, etc.

[0012] As a preferred solution, the weight parts of the solvent in the present invention can be 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, etc.

[0013] As a preferred solution, the preparation method of the epoxy silicone resin includes: by weight, mixing 16 - 20 parts of diphenylsilanediol, 6 - 8 parts of vinyltrimethoxysilane, 3 - 5 parts of γ-glycidoxypropyltrimethoxysilane, 7 - 9 parts of toluene, and 0.02 - 0.04 part of barium hydroxide monohydrate, and carrying out a temperature-raising reaction to obtain the epoxy silicone resin.

[0014] As a preferred solution, the steps of the temperature-raising reaction include: placing it in a nitrogen atmosphere, first raising the temperature to 62 - 66 °C at one time and reacting for 4 - 5 h, then raising the temperature to 80 - 84 °C at the second time and reacting for 3 - 4 h, cooling to room temperature, filtering through a filter membrane to remove the catalyst, and distilling off toluene under reduced pressure.

[0015] The epoxy silicone resin of the present invention uses vinyltrimethoxysilane, γ-glycidyletheroxypropyltrimethoxysilane and diphenylsilanediol as raw materials, and barium hydroxide monohydrate as a catalyst, and prepares the epoxy silicone resin by the sol-gel method. The epoxy silicone resin introduces a large number of benzene rings through diphenylsilanediol. The benzene ring has a planar rigid structure, which can enhance the rigidity of the molecular chain, reduce the movement of chain segments, thereby improving the hardness of the coating. At the same time, the rigid benzene ring can disperse the external friction stress and reduce the expansion of microcracks on the coating surface, thereby delaying wear.

[0016] As a preferred embodiment, the polyamide resin is an amino-terminated hyperbranched polyamide resin HyPer N103; the molecular weight of the amino-terminated hyperbranched polyamide resin HyPer N103 is 1900-2200 g / mol, and the number of amino groups is 12-16 mol.

[0017] The branched structure of the amino-terminated hyperbranched polyamide adsorbs the filler and prevents its agglomeration. At the same time, the hyperbranched molecules act as "bridges" to evenly disperse the external force to the nano-filler and the resin matrix, reducing local stress concentration and improving the hardness of the coating; at the same time, the dendritic branched structure of the resin can fill the micropores and defects in the silicone coating, reduce the porosity of the coating, improve the density and reduce the formation of microcracks during friction, thereby improving the wear resistance.

[0018] As a preferred embodiment, the filler is silica and alumina.

[0019] As a preferred embodiment, the mass ratio of silica to alumina in the filler is (1-2):1, for example, it can be 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1.

[0020] As a preferred embodiment, the particle size of the silica is 20-50 nm; the particle size of the alumina is 200-300 nm; further preferably, the particle size of the silica is 30 nm and the particle size of the alumina is 200 nm.

[0021] The large-particle-size alumina in the composite filler serves as the main wear-resistant phase, providing rigid support and resisting plastic deformation, and bearing most of the friction load. The small-particle-size silica fills the voids of the large-particle-size alumina, forming a dense packing structure and reducing stress concentration; at the same time, alumina and silica jointly construct a wear-resistant skeleton, in which the high wear resistance of alumina directly resists friction loss and reduces the wear rate, and silica fills the voids and inhibits crack propagation, reducing local deformation during friction; through the compounding effect of the two, the hardness and wear resistance of the coating are effectively improved.

[0022] As a preferred embodiment, the titanium dioxide is modified titanium dioxide; The preparation method of the modified titanium dioxide includes: taking 0.4 - 0.8 parts by weight of commercially available titanium dioxide for mercapto-functionalization to obtain mercapto-functionalized titanium dioxide, and using 1-vinyl-3-butylimidazolium tetrafluoroborate to graft-modify the mercapto-functionalized titanium dioxide to obtain the modified titanium dioxide.

[0023] As a preferred embodiment, the mercapto-functionalization step includes: dispersing 0.4 - 0.8 parts of titanium dioxide in 280 - 300 parts of absolute ethanol, then adding 8 - 10 parts of 3-mercaptopropyltrimethoxysilane and performing heat treatment at 46 - 50 °C for 50 - 60 min, then raising the temperature to 80 - 90 °C for reflux reaction for 10 - 12 h, centrifuging, washing with ethanol, and drying under vacuum.

[0024] As a preferred embodiment, the graft-modification step includes: dissolving 0.2 - 0.4 parts of 1-vinyl-3-butylimidazolium tetrafluoroborate in 10 - 12 parts of acetonitrile, then adding it to 50 - 60 parts of absolute ethanol and mixing evenly, then adding 0.4 - 0.8 parts of mercapto-functionalized titanium dioxide and 0.008 - 0.012 parts of azobisisobutyronitrile and stirring for 30 - 40 min for grafting reaction, cooling to room temperature, washing with water, and drying.

[0025] As a preferred embodiment, the conditions for the grafting reaction are: the reaction temperature is 90 - 100 °C, and the reaction time is 20 - 24 h.

[0026] In the present invention, 3-mercaptopropyltrimethoxysilane is first used to perform mercapto-functionalization on titanium dioxide to introduce mercapto groups on the surface of titanium dioxide. Then, taking the mercapto-silane coupling agent as a bridge and using azobisisobutyronitrile as an initiator, the thiol-ene click reaction between the double bond in 1-vinyl-3-butylimidazolium tetrafluoroborate and the mercapto groups on the surface of titanium dioxide is initiated, thereby obtaining the modified titanium dioxide grafted with ionic liquid.

[0027] As a preferred embodiment, the drier is selected from one or more of cobalt isooctanoate, manganese isooctanoate, and cobalt naphthenate.

[0028] As a preferred embodiment, the solvent is selected from xylene or n-butanol.

[0029] In the second aspect of the present invention, a preparation method of a high-hardness organosilicon anti-corrosion coating as described in the first aspect is provided, including the following steps: S1: Taking 40 - 50 parts by weight of epoxy organosilicon resin, 6 - 10 parts of titanium dioxide, and 70 - 90 parts of solvent, adding 0.01 - 0.03 parts of azobisisobutyronitrile and performing heating and stirring treatment to obtain mixture A; S2: Add 40 - 60 parts of polyamide resin, 10 - 15 parts of filler, and 2 - 4 parts of dryer to mixture A, control the temperature at 70 - 80 °C, and stir at a speed of 1400 - 1500 rpm for 20 - 30 min to obtain a high - hardness silicone anticorrosive coating.

[0030] As a preferred solution, the conditions for the heating and stirring treatment include: the temperature is 70 - 80 °C, the stirring speed is 1800 - 2000 rpm, and the time is 60 - 80 min.

[0031] Compared with the prior art, the present invention has the following beneficial effects: (1) The epoxy - functionalized silicone resin of the present invention introduces carbon - carbon double bonds through vinyltrimethoxysilane, and then undergoes a thiol - ene click reaction with modified titanium dioxide containing mercapto groups to introduce titanium dioxide containing ionic liquid into the system. The imidazole - containing ionic liquid can activate the epoxy groups of the epoxy - functionalized silicone resin and promote the nucleophilic attack of amino groups in the terminal - amino - hyperbranched polyamide resin, thereby catalyzing the curing reaction between the epoxy - functionalized silicone resin and the terminal - amino - hyperbranched polyamide resin to form a high - density network structure. In combination with the compounding of silica and alumina with different particle sizes, the network structure of the resin is filled, the movement of polymer chain segments is restricted, and the multi - component synergistic effect improves the hardness and wear resistance of the coating, and good salt - fog resistance and liquid - medium resistance are obtained.

[0032] (2) A large number of benzene rings are introduced into the epoxy - functionalized silicone resin of the present invention through diphenylsilanediol. The benzene ring has a planar rigid structure, which can enhance the rigidity of the molecular chain, reduce the movement of chain segments, thereby improving the hardness of the coating. At the same time, the rigid benzene ring can disperse the external frictional stress and reduce the propagation of micro - cracks on the coating surface, thereby delaying wear.

[0033] (3) The multiple amino groups of the terminal - amino - hyperbranched polyamide of the present invention can react with the functional groups of the silicone resin to form a highly cross - linked three - dimensional network; at the same time, compared with linear polymers, the branch points of the hyperbranched structure provide more reaction sites, effectively improving the cross - link density, forming a three - dimensional interpenetrating network to restrict the movement of molecular chain segments, and obtaining good hardness and wear resistance.

[0034] (4) The ionic liquid introduced by the modified titanium dioxide of the present invention can be compatible with the resin matrix to form a strong interfacial bond, improve the stress transfer efficiency, and reduce the failure caused by stress concentration. Combined with the high hardness of titanium dioxide itself, the overall hardness of the coating is improved; at the same time, the lubricity of the ionic liquid can reduce the aggregation of titanium dioxide particles and improve its dispersion uniformity in the coating, thereby forming a denser coating. The low friction coefficient of the ionic liquid can reduce the wear between particles during friction, thereby increasing the wear resistance of the coating. Detailed implementation mode

[0035] To facilitate the understanding of the present invention, the following embodiments are listed. Those skilled in the art should understand that the said embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0036] The sources of some components in the examples and comparative examples are as follows: Commercially available silicone resin, model SH-1052, from Hubei Longsheng Sihai New Materials Co., Ltd.; Polyamide resin, product number JS0520, purchased from Hubei Jusheng Technology Co., Ltd.; Amino-terminated hyperbranched polyamide resin, model HyPer N103, purchased from Wuhan Hyperbranched Resin Technology Co., Ltd.; Silica, product number S104596, with a particle size of 30 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Aluminum oxide I, product number H102613, with a particle size of 200 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Aluminum oxide II, product number A102005, with a particle size of 5 μm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Commercially available titanium dioxide, product number 104464, purchased from Jiangsu Xianfeng Nanoscience & Technology Co., Ltd.; Cobalt isooctanoate, CAS No. 136-52-7, purchased from Shanghai Macklin Biochemical Co., Ltd.; Manganese isooctanoate, CAS No. 15956-58-8, purchased from Zhongshan Dixin Chemical Co., Ltd.; Cobalt naphthenate, CAS No. 61789-51-3, purchased from Shanghai Macklin Biochemical Co., Ltd.; Xylene, CAS No. 1330-20-7, purchased from Sinopharm Chemical Reagent Co., Ltd.; n-Butanol, CAS No. 71-36-3, purchased from Sinopharm Chemical Reagent Co., Ltd.; Diphenylsilanediol, CAS No. 947-42-2, purchased from Sinopharm Chemical Reagent Co., Ltd.; Vinyltrimethoxysilane, CAS No. 2768-02-7, purchased from Sinopharm Chemical Reagent Co., Ltd.; γ-Glycidoxypropyltrimethoxysilane, CAS No. 2530-83-8, purchased from Shanghai Macklin Biochemical Co., Ltd.; Toluene, CAS No. 108-88-3, purchased from Sinopharm Chemical Reagent Co., Ltd.; Barium hydroxide monohydrate, CAS No. 22326-55-2, purchased from Sinopharm Chemical Reagent Co., Ltd.; 3-Mercaptopropyltrimethylsilane, with CAS number 13399-93-4, was purchased from Shanghai Huayuan Century Trading Co., Ltd.; 1-Vinyl-3-butylimidazolium tetrafluoroborate, with product number M302109, was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Acetonitrile, with CAS number 75-05-8, was purchased from Sinopharm Chemical Reagent Co., Ltd.; 2,2'-Azobis(2-methylpropionitrile), with CAS number 78-67-1, was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0037] Example 1 This example provides a preparation method of a high-hardness silicone anti-corrosion coating, which includes the following steps: S1: By weight, 50 parts of epoxy silicone resin, 10 parts of modified titanium dioxide, and 90 parts of solvent xylene were mixed, and 0.03 parts of 2,2'-azobis(2-methylpropionitrile) was added for heating and stirring treatment (temperature: 80 °C, stirring speed: 1800 rpm, time: 60 min) to obtain mixture A; S2: 60 parts of terminal amino hyperbranched polyamide resin HyPer N103, 15 parts of fillers (10 parts of silica and 5 parts of alumina I), and 4 parts of drier cobalt isooctanoate were added to mixture A, the temperature was controlled at 80 °C, and stirring was carried out at a speed of 1500 rpm for 20 min to obtain the high-hardness silicone anti-corrosion coating.

[0038] The preparation of the epoxy silicone resin: By weight, 20 parts of diphenylsilanediol, 8 parts of vinyltrimethoxysilane, 5 parts of γ-glycidoxypropyltrimethoxysilane, 9 parts of toluene, and 0.04 parts of barium hydroxide monohydrate were mixed, placed in a nitrogen atmosphere, first heated to 66 °C at one time for reaction for 4 h, then heated to 84 °C at the second time for reaction for 3 h, cooled to room temperature, the catalyst was removed by filtration with a filter membrane, and toluene was removed by vacuum distillation to obtain the epoxy silicone resin.

[0039] The preparation of the modified titanium dioxide: By weight, 0.8 parts of titanium dioxide was dispersed in 300 parts of absolute ethanol, then 10 parts of 3-mercaptopropyltrimethylsilane was added for heat treatment at 50 °C for 50 min, then the temperature was raised to 90 °C for reflux reaction for 10 h, centrifuged, washed with ethanol, and dried in vacuum to obtain mercapto-functionalized titanium dioxide; 0.4 parts of 1-vinyl-3-butylimidazolium tetrafluoroborate was dissolved in 12 parts of acetonitrile, then added to 60 parts of absolute ethanol and mixed evenly, then 0.8 parts of mercapto-functionalized titanium dioxide and 0.012 parts of 2,2'-azobis(2-methylpropionitrile) were added and stirred for 40 min for grafting reaction (temperature: 100 °C, time: 20 h), cooled to room temperature, washed with water, and dried to obtain the modified titanium dioxide.

[0040] Example 2 This embodiment provides a method for preparing a high-hardness silicone anti-corrosion coating, comprising the following steps: S1: By weight, mix 40 parts of epoxy silicone resin, 6 parts of modified titanium dioxide, and 70 parts of solvent n-butanol, add 0.01 part of azobisisobutyronitrile, and perform heat-up stirring treatment (temperature is 70 °C, stirring speed is 1800 rpm, time is 80 min) to obtain mixture A; S2: Add 40 parts of terminal amino hyperbranched polyamide resin HyPer N103, 10 parts of fillers (5 parts of silica and 5 parts of alumina I), and 2 parts of drier manganese isooctanoate to mixture A, control the temperature at 70 °C, and stir at a speed of 1400 rpm for 30 min to obtain the high-hardness silicone anti-corrosion coating.

[0041] Preparation of the epoxy silicone resin: By weight, mix 16 parts of diphenylsilanediol, 6 parts of vinyltrimethoxysilane, 3 parts of γ-glycidyletheroxypropyltrimethoxysilane, 7 parts of toluene, and 0.02 part of barium hydroxide monohydrate, place it in a nitrogen atmosphere, first heat up to 62 °C at one time and react for 5 h, then heat up to 80 °C at the second time and react for 4 h, cool to room temperature, filter through a membrane to remove the catalyst, and remove toluene by vacuum distillation to obtain the epoxy silicone resin.

[0042] Preparation of the modified titanium dioxide: By weight, disperse 0.4 part of titanium dioxide in 280 parts of absolute ethanol, then add 8 parts of 3-mercaptopropyltrimethylsilane and perform heat treatment at 46 °C for 60 min, then heat up to 80 °C for reflux reaction for 12 h, centrifuge, wash with ethanol, and dry in vacuum to obtain mercapto-functionalized titanium dioxide; dissolve 0.2 part of 1-vinyl-3-butylimidazolium tetrafluoroborate in 10 parts of acetonitrile, then add it to 50 parts of absolute ethanol and mix evenly, then add 0.4 part of mercapto-functionalized titanium dioxide and 0.008 part of azobisisobutyronitrile and stir for 30 min for grafting reaction (temperature is 90 °C, time is 24 h), cool to room temperature, wash with water, and dry to obtain the modified titanium dioxide.

[0043] Example 3 This embodiment provides a method for preparing a high-hardness silicone anti-corrosion coating, comprising the following steps: S1: By weight, mix 45 parts of epoxy silicone resin, 8 parts of modified titanium dioxide, and 80 parts of solvent xylene, add 0.02 part of azobisisobutyronitrile, and perform heat-up stirring treatment (temperature is 75 °C, stirring speed is 1900 rpm, time is 70 min) to obtain mixture A; S2: Add 50 parts of amino-terminated hyperbranched polyamide resin HyPer N103, 12 parts of fillers (7 parts of silica and 5 parts of alumina I), and 3 parts of cobalt naphthenate drier to mixture A, control the temperature at 75 °C, and stir for 25 min at a rotation speed of 1450 rpm to obtain a high-hardness silicone anticorrosive coating.

[0044] Preparation of the epoxy silicone resin: By weight, mix 18 parts of diphenylsilanediol, 7 parts of vinyltrimethoxysilane, 4 parts of γ-glycidyletheroxypropyltrimethoxysilane, 8 parts of toluene, and 0.03 part of barium hydroxide monohydrate, place it under a nitrogen atmosphere, first raise the temperature to 65 °C at one time and react for 4.5 h, then raise the temperature to 82 °C for the second time and react for 3.5 h, cool to room temperature, filter through a membrane to remove the catalyst, and remove toluene by vacuum distillation to obtain the epoxy silicone resin.

[0045] Preparation of the modified titanium dioxide: By weight, disperse 0.6 part of titanium dioxide in 290 parts of absolute ethanol, then add 9 parts of 3-mercaptopropyltrimethylsilane and heat-treat at 48 °C for 55 min, then raise the temperature to 85 °C for reflux reaction for 11 h, centrifuge, wash with ethanol, and dry in vacuum to obtain mercapto-functionalized titanium dioxide; dissolve 0.3 part of 1-vinyl-3-butylimidazolium tetrafluoroborate in 11 parts of acetonitrile, then add it to 55 parts of absolute ethanol and mix evenly, then add 0.6 part of mercapto-functionalized titanium dioxide and 0.009 part of azobisisobutyronitrile and stir for 35 min for grafting reaction (temperature is 95 °C, time is 22 h), cool to room temperature, wash with water, and dry to obtain the modified titanium dioxide.

[0046] Example 4 The difference between this example and Example 1 is that commercially available titanium dioxide (product number 104464) is used to replace the modified titanium dioxide.

[0047] Comparative Example 1 The difference between this comparative example and Example 1 is that commercially available silicone resin (model SH-1052) is used to replace the epoxy silicone resin.

[0048] Comparative Example 2 The difference between this comparative example and Example 1 is that ordinary polyamide resin (product number JS0520) is used to replace the amino-terminated hyperbranched polyamide resin HyPer N103.

[0049] Comparative Example 3 The difference between this comparative example and Example 1 is that alumina II (product number A102005, particle size 5 μm) is used in the filler to replace alumina I (product number H102613, particle size 200 nm).

[0050] Comparative Example 4 The difference between this comparative example and Example 1 is that the amount of silica in the filler is changed to 13 parts, and the amount of alumina I is changed to 2 parts.

[0051] Comparative Example 5 The difference between this comparative example and Example 1 is that the amount of silica in the filler is changed to 5 parts, and the amount of alumina I is changed to 10 parts.

[0052] The properties of the coatings provided by the above examples and comparative examples after normal film formation were tested. The test methods are as follows: (1)Pencil hardness test: The test was carried out with reference to the requirements of "GB / T 6739-2022 Paints and varnishes - Determination of film hardness by pencil method".

[0053] (2)Abrasion resistance test: The test was carried out with reference to the requirements of "GB / T 1768-2006 Paints and varnishes - Determination of abrasion resistance - Rotating rubber wheel method", with the conditions of 1000 cycles, No. 10 wheel, and a load of 1 kg.

[0054] (3)Salt spray resistance test: The test was carried out with reference to the requirements of "GB / T 2423.17-2024 Environmental testing - Part 2: Test methods - Test Ka: Salt spray".

[0055] (4)Resistance to liquid media test: The test was carried out with reference to the requirements of "GB / T 30648.1-2014 Paints and varnishes - Determination of resistance to liquids - Part 1: Immersion in liquids other than water".

[0056] The above performance test data are shown in Table 1.

[0057] Table 1 Performance test results Pencil hardness Abrasion resistance (mg) Salt spray resistance Resistance to liquid media Example 1 6H 9.1 No rust, no blistering, no peeling No rust, no blistering, no peeling Example 2 6H 9.8 No rust, no blistering, no peeling No rust, no blistering, no peeling Example 3 6H 9.5 No rust, no blistering, no peeling No rust, no blistering, no peeling Example 4 3H 17.5 No rust, no blistering, no peeling No rust, no blistering, no peeling Comparative Example 1 2H 18.6 No rust, no blistering, no peeling No rust, no blistering, no peeling Comparative Example 2 3H 16.9 No rust, no blistering, no peeling No rust, no blistering, no peeling Comparative Example 3 3H 16.2 No rust, no blistering, no peeling No rust, no blistering, no peeling Comparative Example 4 4H 11.9 No rust, no blistering, no peeling No rust, no blistering, no peeling Comparative Example 5 4H 12.3 No rust, no blistering, no peeling No rust, no blistering, no peeling As can be seen from the above content, the present invention uses vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and diphenylsilanediol as raw materials to prepare an epoxy organosilicon resin, and in combination with the co-use of an amino-terminated hyperbranched polyamide resin, a composite filler, and modified titanium dioxide, a high-hardness organosilicon anti-corrosion coating (Examples 1 to 3) is prepared, and its comprehensive performance is better.

[0058] Compared with Example 1, when using commercially available titanium dioxide (product number 104464) to replace the modified titanium dioxide, since the commercially available titanium dioxide Ⅰ is not modified to introduce mercapto groups and ionic liquids, the hardness of the coating decreases and the wear resistance becomes poor (Example 4); compared with Example 1, when using commercially available silicone resin (model SH-1052) to replace the epoxidized silicone resin, due to the lack of the rigid effect of a large number of benzene rings and the lack of active groups such as epoxy groups and double bonds to construct the network, the hardness of the coating decreases and the wear resistance becomes poor (Comparative Example 1); compared with Example 1, when using ordinary polyamide resin (product number JS0520) to replace the hyperbranched polyamide resin with terminal amino groups HyPer N103, due to the lack of the dendritic branched structure and the effect of terminal amino groups, the hardness of the coating decreases and the wear resistance becomes poor (Comparative Example 2); compared with Example 1, when using alumina Ⅱ (product number A102005, particle size 5 μm) to replace alumina Ⅰ (product number H102613, particle size 200 nm), due to the too large particle size of alumina Ⅱ and the poor effect of filler blending, the hardness of the coating decreases and the wear resistance becomes poor (Comparative Example 3); compared with Example 1, when the amount of silica in the filler is changed to 13 parts and the amount of alumina Ⅰ is changed to 2 parts, due to the too small amount of alumina Ⅰ and insufficient rigid support, the hardness of the coating decreases and the wear resistance becomes poor (Comparative Example 4); compared with Example 1, when the amount of silica in the filler is changed to 5 parts and the amount of alumina Ⅰ is changed to 10 parts, due to the too small amount of silica and the difficulty in forming a dense packing structure, the hardness of the coating decreases and the wear resistance becomes poor (Comparative Example 5).

[0059] In summary, the epoxidized silicone resin of the present invention introduces carbon-carbon double bonds through vinyltrimethoxysilane, and then undergoes a thiol-ene click reaction with the modified titanium dioxide containing mercapto groups to introduce titanium dioxide containing ionic liquids into the system. The ionic liquid containing imidazole can activate the epoxy groups of the epoxidized silicone resin and promote the nucleophilic attack of the amino groups in the hyperbranched polyamide resin with terminal amino groups, thereby catalyzing the curing reaction of the epoxidized silicone resin and the hyperbranched polyamide resin with terminal amino groups to form a high-density network structure. By cooperating with the blending of silica and alumina with different particle sizes, the network structure of the resin is filled, the movement of polymer chain segments is restricted, and the multi-component synergistic effect is achieved, improving the hardness and wear resistance of the coating and obtaining good salt spray resistance and liquid medium resistance.

Claims

1. A high-hardness organic silicon anti-corrosion coating, characterized in that: The composition comprises the following components in parts by weight: 40 to 50 parts of epoxidized silicone resin, 40 to 60 parts of polyamide resin, 10 to 15 parts of filler, 6 to 10 parts of titanium dioxide, 2 to 4 parts of drying agent and 70 to 90 parts of solvent; The preparation method of the epoxidized silicone resin comprises: mixing 16 to 20 parts by weight of diphenylsilanediol, 6 to 8 parts of vinyltrimethoxysilane, 3 to 5 parts of γ-glycidyloxypropyltrimethoxysilane, 7 to 9 parts of toluene and 0.02 to 0.04 parts of monohydrated barium hydroxide and reacting the mixture at elevated temperature to obtain the epoxidized silicone resin.

2. A high-hardness organic silicon anti-corrosion coating according to claim 1, characterized in that: The temperature-raising reaction step comprises: placing under a nitrogen atmosphere, heating to 62-66° C. for a first time for reaction for 4-5 hours, heating to 80-84° C. for a second time for reaction for 3-4 hours, cooling to room temperature, filtering to remove the catalyst with a filter membrane, and removing toluene by reduced pressure distillation.

3. The high-hardness organic silicon anticorrosive coating according to claim 1, characterized in that: The polyamide resin is amino-terminated hyperbranched polyamide resin HyPer N103.

4. The high-hardness organic silicon anticorrosive coating according to claim 1, characterized in that: The fillers are silicon dioxide and aluminum oxide; The mass ratio of silicon dioxide to aluminum oxide in the filler is (1-2):

1.

5. The high-hardness organic silicon anticorrosive coating according to claim 4, characterized in that: The particle size of the silicon dioxide is 20-50 nm; the particle size of the aluminum oxide is 200-300 nm.

6. The high-hardness organic silicon anticorrosive coating according to claim 1, characterized in that: The titanium dioxide is modified titanium dioxide; The preparation method of the modified titanium dioxide comprises: mercapto-modifying 0.4-0.8 parts of commercially available titanium dioxide by weight to obtain mercapto-modified titanium dioxide, and graft-modifying the mercapto-modified titanium dioxide using 1-vinyl-3-butyl imidazole tetrafluoroborate to obtain modified titanium dioxide.

7. The high-hardness organic silicon anticorrosive coating according to claim 6, characterized in that: The thiolation step comprises: dispersing 0.4-0.8 parts of titanium dioxide in 280-300 parts of anhydrous ethanol, then adding 8-10 parts of 3-mercaptopropyltrimethylsilane and heat treating at 46-50° C. for 50-60 minutes, then heating to 80-90° C. for reflux reaction for 10-12 hours, centrifuging, washing with ethanol, and vacuum drying.

8. The high-hardness organic silicon anticorrosive coating according to claim 6, characterized in that: The grafting modification step comprises: dissolving 0.2-0.4 parts of 1-vinyl-3-butyl imidazole tetrafluoroborate in 10-12 parts of acetonitrile, then adding into 50-60 parts of anhydrous ethanol and mixing evenly, then adding 0.4-0.8 parts of thiolated titanium dioxide and 0.008-0.012 parts of azobisisobutyronitrile and stirring for 30-40 minutes to carry out grafting reaction, cooling to room temperature, washing with water, and drying.

9. The high-hardness organic silicon anticorrosive coating according to claim 1, characterized in that: The drying agent is selected from one or more of cobalt isooctanoate, manganese isooctanoate, and cobalt naphthenate; The solvent is selected from xylene or n-butanol.

10. A method for preparing a high-hardness organosilicon anticorrosive coating according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: In parts by weight, 40-50 parts of epoxidized silicone resin, 6-10 parts of titanium dioxide and 70-90 parts of solvent are mixed, and 0.01-0.03 parts of azobisisobutyronitrile are added, and the mixture is heated and stirred to obtain a mixture A; S2: Add 40-60 parts of polyamide resin, 10-15 parts of filler and 2-4 parts of drying agent to mixture A, control the temperature to 70-80°C, stir at a speed of 1400-1500 rpm for 20-30 minutes, and obtain a high-hardness organosilicon anti-corrosion coating.