A silicone-modified epoxy temperature-resistant anticorrosive primer, a preparation method and application thereof

Abstract

The present application relates to a kind of aluminium alloy, cast iron etc. Base material with organic silicon modified epoxy temperature-resistant anticorrosive primer, it is made of component A, component B and component C;Component A includes organic silicon modified epoxy resin, bisphenol A type epoxy resin, phenolic epoxy resin, active diluent, auxiliary agent, pigment, filler, first ester solvent;Component B includes aliphatic polyamide curing agent, modified amine curing agent, curing accelerator, second ester solvent and alcohol solvent;Component C includes second ester solvent, alcohol solvent and silane coupling agent.By organic silicon modified epoxy resin, combine the high temperature resistance of organic silicon resin and the high adhesion, high water resistance, thermal stability of epoxy resin, and compound bisphenol A type epoxy resin and phenolic resin, and add non-toxic anticorrosive colorant, auxiliary agent, VOC exempt solvent, prepare good environmental protection primer, and can be long-term applied in 250℃ high temperature environment under low film thickness, also have excellent mechanical properties, anticorrosive and chemical medium resistance.

Description

Technical Field

[0001] This invention relates to the field of functional coatings technology, and more specifically, to an organosilicon-modified epoxy heat-resistant and corrosion-resistant primer, its preparation method, and its application. Background Technology

[0002] Aero engines operate at prolonged high temperatures, which adversely affects the casing materials and safety. Developing and applying high-performance, high-temperature resistant coatings is essential to address this issue. High-temperature resistant coatings mainly include inorganic and organic types. Organosilicon high-temperature resistant coatings have excellent high-temperature resistance and are currently the most widely used organic high-temperature coatings. However, traditional organic coatings are prone to degradation or carbonization at high temperatures, leading to failure. Furthermore, they contain heavy metals such as lead and chromium, causing significant environmental pollution. Inorganic coatings have good temperature resistance and are easy to prepare for high-temperature applications, but they often lack sufficient toughness. Therefore, developing a coating that is both high-temperature resistant and environmentally friendly while meeting toughness requirements is of great significance and has a promising market prospect. Moreover, aero engines operate in complex environments, frequently in high-altitude and marine environments, demanding even higher corrosion resistance from coatings.

[0003] Based on the above, developing an environmentally friendly, corrosion-resistant, high-temperature resistant primer with excellent mechanical properties has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a silicone-modified epoxy high-temperature resistant and anti-corrosion primer. By modifying the epoxy resin with silicone, combining the high-temperature resistance of silicone resin with the high adhesion, high water resistance, and thermal stability of epoxy resin, and further compounding bisphenol A type epoxy resin and phenolic resin, and adding various non-toxic anti-rust pigments, additives, and VOC-exempt solvents, the resulting primer exhibits excellent environmental friendliness and can be used for extended periods in high-temperature environments of 250℃ with low film thickness (17-22μm). It also possesses excellent adhesion, corrosion resistance, and resistance to chemical media.

[0005] One of the objectives of this invention is to provide a silicone-modified epoxy high-temperature resistant and anti-corrosion primer, which comprises component A, component B, and component C.

[0006] Component A includes silicone-modified epoxy resin, bisphenol A type epoxy resin, phenolic epoxy resin, reactive diluent, additives, pigments, fillers, and primary ester solvents;

[0007] Component B includes polyamide curing agent, modified amine curing agent, curing accelerator, second ester solvent, and alcohol solvent;

[0008] Component C includes second ester solvents, alcohol solvents, and coupling agents;

[0009] Component A comprises, by weight, 100 parts:

[0010]

[0011] The components of component B, in units of 100 parts by total weight:

[0012]

[0013] The C component, in parts per 100 parts by total weight:

[0014] 77-87 parts by weight of diester solvent

[0015] 8-13 parts by weight of alcohol solvents

[0016] 5-10 parts by weight of coupling agent;

[0017] The mass ratio of components A, B, and C is 7–9:1:4–6, preferably 7–8:1:4–5. Technical personnel can select a suitable mass ratio of components A, B, and C according to actual needs.

[0018] In component A, the bisphenol A type epoxy resin is one or more of 618, 6101, 637, and 634; the phenolic epoxy resin is one or more of F44, F51, DEN425, and DEN431; and the reactive diluent is one or more of 660, 6360, 5784, and 692. In component B, the polyamide curing agent is one or more of Versamid 150, Versamid 125, Versamid 140, and Sunmide 305; the modified amine curing agent is one or more of JH5473, JH5432S, and EH3895L; and the curing accelerator is one or more of Ancamine K54, DMP-30, and OP8658. In component C, the coupling agent is one or more of KH550, KH560, KH570, and KH125. Technicians can select appropriate bisphenol A epoxy resin, phenolic epoxy resin, reactive diluent, polyamide curing agent, modified amine curing agent, curing accelerator and coupling agent according to actual needs.

[0019] In a preferred embodiment of the present invention, component A comprises 100 parts by total weight:

[0020]

[0021] The components of component B, in parts of a total weight of 100:

[0022]

[0023] The C component, in parts per 100 parts by total weight:

[0024] 80-85 parts by weight of second ester solvent

[0025] 9-11 parts by weight of alcohol solvent

[0026] 6-9 parts by weight of coupling agent.

[0027] In a preferred embodiment of the present invention, in component A, the organosilicon-modified epoxy resin is prepared by reacting the following raw materials.

[0028]

[0029] In a preferred embodiment of the present invention, the phenylsiloxane resin is one or two of vinyl-terminated methylphenyl polysiloxane, polydimethylsiloxane, phenyl polytrimethylsiloxane, and phenyl-modified polysiloxane.

[0030] In a preferred embodiment of the present invention, the organosilicon-modified epoxy resin is prepared by the following method:

[0031] S1: Mix epoxy resin and xylene, and heat;

[0032] S2: Add phenylsiloxane resin and color changer, then heat;

[0033] S3: Add catalyst dropwise and heat to react;

[0034] S4: Cool down, add butyl acetate, react to obtain organosilicon modified epoxy resin;

[0035] The present invention can specifically adopt the following technical solutions:

[0036] S1: Add epoxy resin and xylene to the reactor and slowly heat up;

[0037] S2: Add phenylsiloxane resin and color changer to epoxy resin and xylene, and heat up under nitrogen protection.

[0038] S3: Add catalyst dropwise, stir thoroughly until homogeneous, heat and maintain the temperature, and continue stirring to obtain a transparent liquid;

[0039] S4: Cool the transparent liquid, add butyl acetate, stir, filter and package to obtain silicone-modified epoxy resin.

[0040] In this invention, the epoxy resin is one or two of 601, 6101, 638, and GY250. The catalyst is dibutyltin dilaurate. Technicians can select a suitable epoxy resin according to actual needs. For the color-changing agent of the organosilicon-modified epoxy resin, commercially available options are acceptable.

[0041] In a preferred embodiment of the present invention, in step S1, the temperature is 55–60°C; in step S2, the temperature is 75–80°C; in step S3, the temperature is 105–115°C, and the reaction time is 3–5 hours; in step S4, the temperature is 70–90°C, and the reaction time is 2–3 hours. Those skilled in the art can select appropriate reaction temperatures and reaction times according to actual conditions.

[0042] In a preferred embodiment of the present invention, in component A, the filler is two or more selected from barium sulfate, modified talc, alumina, diatomaceous earth, fumed silica, mica powder, organobentonite, and conductive graphite; the pigment includes environmentally friendly anti-rust pigments and coloring pigments; wherein, the environmentally friendly anti-rust pigment is preferably two or more selected from zinc molybdate, zinc phosphate, modified zinc phosphate, composite zinc phosphate, high-purity zinc phosphate, aluminum tripolyphosphate, and polymeric anti-rust materials; the coloring pigment is preferably titanium dioxide, iron oxide red, or various BASF pigments; the first ester solvent is at least one selected from ethyl acetate, butyl acetate, and tert-butyl acetate. Those skilled in the art can select appropriate fillers, pigments, and the first ester solvent according to actual conditions.

[0043] The additives include wetting and dispersing agents, defoamers, ultraviolet absorbers, and antioxidants. Preferably, the defoamer is one or two of modified polysiloxane or polyether solutions; the wetting and dispersing agent is one or more of EFKA4310, EFKA4700, AFCONA4015, AFCONA4010, and AFCONA4071; the antioxidant is one or more of 168, 628, and 1076; and the ultraviolet absorber is one or more of UV-P, UV-5050, UV531, and UV328. Technical personnel can select appropriate additives based on actual conditions.

[0044] In a preferred embodiment of the present invention, in components B and C,

[0045] The second ester solvent in components B and C may be the same or different, and may be independently selected from one or more of ethyl acetate, butyl acetate, tert-butyl acetate, and propylene glycol methyl ether acetate; and / or

[0046] The alcohol solvent is one or both of n-butanol and isopropanol.

[0047] In a preferred embodiment of the present invention, component A is prepared by the following method:

[0048] (1) The organosilicon modified epoxy resin, the first ester solvent, the wetting and dispersing agent, the defoamer, the environmentally friendly rust-preventing pigment, the coloring pigment, the antioxidant, the ultraviolet absorber, and the filler are mixed and stirred to obtain a mixed slurry;

[0049] (2) Grind the mixed slurry to a fineness of ≤15μm, then add the bisphenol A type epoxy resin, phenolic epoxy resin and reactive diluent, disperse and mix evenly to obtain component A.

[0050] The present invention can specifically adopt the following technical solutions:

[0051] (1) Add organosilicon-modified epoxy resin, first ester solvent, wetting and dispersing agent, and defoamer to a mobile tank and stir at high speed for 10-20 minutes;

[0052] (2) Switch from high-speed stirring to low-speed stirring, and add environmentally friendly rust-preventive pigment, coloring pigment, antioxidant, ultraviolet absorber and filler in sequence under low-speed stirring. Disperse at high speed for 30 to 60 minutes to obtain a mixed slurry.

[0053] (3) Grind the mixed slurry to a fineness of ≤15μm, then add bisphenol A type epoxy resin, phenolic epoxy resin and reactive diluent, disperse at low speed for 30-60min, mix evenly, and adjust the non-volatile content to 70%-75% to obtain component A.

[0054] In this invention, component B is prepared by the following method: a polyamide curing agent, a modified amine curing agent, a curing accelerator, a second ester solvent, and an alcohol solvent are mixed and stirred for 30-60 minutes, and the non-volatile content is adjusted to 68%-72% to obtain component B; component C is prepared by the following method: a second ester solvent, an alcohol solvent, and a coupling agent are mixed and stirred for 10 minutes, and then the non-volatile content is adjusted to no more than 25 mg per 100 ml to obtain component C.

[0055] The second objective of this invention is to provide a method for preparing an organosilicon-modified epoxy heat-resistant and corrosion-resistant primer, one of the objectives of this invention, the method comprising:

[0056] The components of component A are mixed in parts by weight to obtain component A; the components of component B are mixed in parts by weight to obtain component B; the components of component C are mixed in parts by weight to obtain component C; after mixing components A, B and C in the specified amounts, the mixture is cured to obtain an organosilicon-modified epoxy heat-resistant and anti-corrosion primer.

[0057] The third objective of this invention is to provide an application of a silicone-modified epoxy high-temperature resistant and anti-corrosion primer prepared according to one objective of this invention or a silicone-modified epoxy high-temperature resistant and anti-corrosion primer prepared according to another objective of this invention on the surface of metal materials.

[0058] First, pretreatment of the substrate is performed. For aluminum alloy substrates, the treatment should first involve solvent cleaning (acetone or methyl ethyl ketone), followed by polishing in clean water until a continuous water film appears for 30 seconds, then rinsing with distilled water. Surface treatment can then be performed using allodin (or sulfuric acid anodizing or chromic acid anodizing). For substrates such as cast iron, mechanical polishing and solvent wiping are sufficient for application. Next, spraying is performed: Components A, B, and C are thoroughly mixed and allowed to mature for 10 minutes. After filtering through a 120-mesh or finer filter, the mixture is sprayed using conventional air spraying. The preferred nozzle size is 0.8–1.2 mm, the preferred atomization pressure is 2.0–3.0 bar, and the preferred viscosity (Co-4 cup) is 15–20 s. Preferably, the dry film thickness of the silicone-modified epoxy heat-resistant and corrosion-resistant primer on the metal surface is 17–22 μm.

[0059] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0060] 1. The silicone-modified epoxy high-temperature resistant and anti-corrosion primer of the present invention uses fillers formed by mixing various metal oxides, which can effectively form a dense protective layer on the steel surface, isolating it from the surrounding substances, and can effectively protect the substrate and engine for a long time. Furthermore, since it does not contain toxic anti-rust materials such as lead and chromium and non-exempt solvents, it plays a good role in protecting the environment.

[0061] 2. The silicone-modified epoxy high-temperature and corrosion-resistant primer of the present invention has excellent flexibility, adhesion, water resistance, chemical resistance, high and low temperature resistance, impact resistance and corrosion resistance. It can be used for a long time in a high-temperature environment of 250°C with low film thickness.

[0062] 3. The silicone-modified epoxy heat-resistant and anti-corrosion primer of the present invention can be applied to the surface of various metal materials, serving as a marker, corrosion protectant, and substrate thermal oxidation protectant. Detailed Implementation

[0063] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0064] The raw materials used in the examples and comparative examples were all commercially available.

[0065] The parts in the examples and comparative examples refer to parts by weight.

[0066] Example 1

[0067] 1. An organosilicon-modified epoxy heat-resistant and corrosion-resistant primer, composed of three components A, B, and C, with the following raw material mass ratios for each component:

[0068] (1) Component A includes: 28 parts of silicone-modified epoxy resin, 0.05 parts of defoamer, 1 part of wetting and dispersing agent, 14 parts of environmentally friendly anti-rust pigment, 7 parts of functional filler, 16 parts of coloring pigment, 0.05 parts of antioxidant, 0.1 parts of ultraviolet absorber, 8 parts of primary ester solvent, 18 parts of bisphenol A type epoxy resin, 4.8 parts of phenolic epoxy resin, and 3 parts of reactive diluent.

[0069] Among them, the environmentally friendly anti-rust pigment in component A is a compound of zinc molybdate, high-purity zinc phosphate, and modified aluminum tripolyphosphate in a weight ratio of 4:2:1; the functional filler is a compound of mica powder, talc powder, barium sulfate, alumina, and conductive graphite in a weight ratio of 1:1.5:1:1.5:0.05; and the first ester solvent is a compound of butyl acetate and tert-butyl acetate in a weight ratio of 1:1.

[0070] The silicone-modified epoxy resin is prepared by reacting the following raw materials.

[0071]

[0072] The preparation method of this silicone-modified epoxy resin is as follows:

[0073] S1: Add epoxy resin and xylene to the reactor and slowly heat to 60℃;

[0074] S2: Add phenylsiloxane resin and color changer to epoxy resin and xylene, and heat to 80°C under nitrogen protection.

[0075] S3: Add catalyst dropwise, stir thoroughly, heat to 110℃ and keep warm, stir continuously for 3 hours to obtain a transparent liquid;

[0076] S4: Cool the transparent liquid to 80℃, then add butyl acetate, stir for 2 hours, filter and package to obtain silicone-modified epoxy resin.

[0077] (2) Component B includes: 46 parts of polyamide curing agent, 24 parts of modified amine curing agent, 6 parts of curing accelerator, 19 parts of tert-butyl acetate, and 5 parts of n-butanol.

[0078] (3) Component C includes: 10 parts isopropanol, 40 parts tert-butyl acetate, 43 parts butyl acetate, and 7 parts coupling agent.

[0079] 2. Preparation method of silicone-modified epoxy high-temperature resistant and anti-corrosion primer:

[0080] (1) Preparation of component A: Add organosilicon modified epoxy resin, first ester solvent, wetting and dispersing agent, and defoamer to a mobile tank and stir at high speed for 20 min. Then, add environmentally friendly anti-rust pigment, coloring pigment, antioxidant, ultraviolet absorber, and filler in sequence while stirring at low speed. Disperse at high speed for 60 min to obtain a mixed slurry. Grind the mixed slurry to a fineness of ≤15 μm. Then, add bisphenol A type epoxy resin, phenolic epoxy resin, and reactive diluent. Disperse at low speed for 60 min. After mixing evenly, adjust the non-volatile content to 70% to obtain component A.

[0081] (2) Preparation of component B: Mix polyamide curing agent, modified amine curing agent, curing accelerator, tert-butyl acetate and n-butanol, stir for 60 min, and adjust the non-volatile content to 70% to obtain component B.

[0082] (3) Preparation of component C: Mix isopropanol, tert-butyl acetate, butyl acetate and coupling agent, stir for 10 min, and then adjust the non-volatile content to no more than 25 mg per 100 ml to obtain component C.

[0083] Mixing before application: Mix components A, B, and C thoroughly in a weight ratio of 8:1:4. After maturing for 10 minutes, you will get a silicone-modified epoxy heat-resistant and anti-corrosion primer. After filtering with a filter screen of 120 mesh or higher, it is ready for spraying.

[0084] 3. Application process of silicone-modified epoxy high-temperature resistant and anti-corrosion primer:

[0085] Substrate pretreatment: When treating aluminum alloy substrates, first clean them with solvent (acetone or methyl ethyl ketone), then polish them in clean water until a continuous water film appears for 30 seconds, then clean them with distilled water, and then perform surface treatment with allodin (or sulfuric acid anodizing or chromic acid anodizing).

[0086] Spraying: Conventional air spraying is used, with a preferred nozzle size of 0.8mm and a preferred atomization pressure of 2.0 bar. The final product is a silicone-modified epoxy heat-resistant and corrosion-resistant primer film with a dry film thickness of 22μm and a Coating-4 cup viscosity of 15-20s.

[0087] Example 2

[0088] 1. An organosilicon-modified epoxy heat-resistant and corrosion-resistant primer, composed of three components A, B, and C, with the following raw material mass ratios for each component:

[0089] (1) Component A includes: 26 parts of silicone-modified epoxy resin, 0.1 parts of defoamer, 1 part of wetting and dispersing agent, 13 parts of environmentally friendly anti-rust pigment, 8 parts of functional filler, 16 parts of coloring pigment, 0.05 parts of antioxidant, 0.1 parts of ultraviolet absorber, 8 parts of primary ester solvent, 19 parts of bisphenol A type epoxy resin, 5.75 parts of phenolic epoxy resin, and 3 parts of reactive diluent.

[0090] Among them, the environmentally friendly anti-rust pigment in component A is a compound of zinc molybdate, modified zinc phosphate, and polymeric anti-rust material in a weight ratio of 8:5:1; the functional filler is a compound of mica powder, talc powder, barium sulfate, alumina, and fumed silica in a weight ratio of 1:1.5:1:1.5:0.1; and the first ester solvent is a compound of butyl acetate and tert-butyl acetate in a weight ratio of 1:1.

[0091] The silicone-modified epoxy resin is prepared by reacting the following raw materials.

[0092]

[0093] The preparation method of this organosilicon-modified epoxy resin is the same as in Example 1.

[0094] (2) Component B includes: 43 parts of polyamide curing agent, 28 parts of modified amine curing agent, 5 parts of curing accelerator, 19 parts of tert-butyl acetate, and 5 parts of n-butanol.

[0095] (3) Component C includes: 10 parts isopropanol, 40 parts tert-butyl acetate, 43 parts butyl acetate, and 7 parts coupling agent.

[0096] 2. Preparation method of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0097] 3. Construction process of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0098] Example 3

[0099] 1. An organosilicon-modified epoxy heat-resistant and corrosion-resistant primer, composed of three components A, B, and C, with the following raw material mass ratios for each component:

[0100] (1) Component A includes: 29 parts of silicone-modified epoxy resin, 0.05 parts of defoamer, 1 part of wetting and dispersing agent, 14 parts of environmentally friendly anti-rust pigment, 7 parts of functional filler, 16 parts of coloring pigment, 0.05 parts of antioxidant, 0.1 parts of ultraviolet absorber, 8 parts of primary ester solvent, 17 parts of bisphenol A type epoxy resin, 4.8 parts of phenolic epoxy resin, and 3 parts of reactive diluent.

[0101] Among them, the environmentally friendly anti-rust pigment in component A is a compound of zinc molybdate, modified zinc phosphate, and modified aluminum tripolyphosphate in a weight ratio of 10:5:1; the functional filler is a compound of mica powder, talc powder, barium sulfate, alumina, and conductive graphite in a weight ratio of 1:1.5:1:1.5:0.05; and the first ester solvent is a compound of butyl acetate and tert-butyl acetate in a weight ratio of 1:1.

[0102] The silicone-modified epoxy resin is prepared by reacting the following raw materials.

[0103]

[0104] The preparation method of this organosilicon-modified epoxy resin is the same as in Example 1.

[0105] (2) Component B includes: 47 parts of polyamide curing agent, 22 parts of modified amine curing agent, 7 parts of curing accelerator, 19 parts of tert-butyl acetate, and 5 parts of n-butanol.

[0106] (3) Component C includes: 10 parts isopropanol, 40 parts tert-butyl acetate, 43 parts butyl acetate, and 7 parts coupling agent.

[0107] 2. Preparation method of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0108] 3. Construction process of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0109] Example 4

[0110] 1. An organosilicon-modified epoxy heat-resistant and corrosion-resistant primer, composed of three components A, B, and C, with the following raw material mass ratios for each component:

[0111] (1) Component A includes: 23 parts of silicone-modified epoxy resin, 0.05 parts of defoamer, 1 part of wetting and dispersing agent, 14 parts of environmentally friendly anti-rust pigment, 8 parts of functional filler, 16 parts of coloring pigment, 0.05 parts of antioxidant, 0.1 parts of ultraviolet absorber, 8 parts of primary ester solvent, 21 parts of bisphenol A type epoxy resin, 5.8 parts of phenolic epoxy resin, and 3 parts of reactive diluent.

[0112] Among them, the environmentally friendly anti-rust pigment in component A is a compound of zinc molybdate, high-purity zinc phosphate, modified aluminum tripolyphosphate, and polymeric anti-rust material in a weight ratio of 4:2:1:1.5; the functional filler is a compound of mica powder, talc powder, barium sulfate, alumina, and fumed silica in a weight ratio of 1:1.5:1:1.5:0.1; and the first ester solvent is a compound of butyl acetate and tert-butyl acetate in a weight ratio of 1:1.

[0113] The silicone-modified epoxy resin is prepared by reacting the following raw materials.

[0114]

[0115] The preparation method of this organosilicon-modified epoxy resin is the same as in Example 1.

[0116] (2) Component B includes: 44 parts of polyamide curing agent, 26 parts of modified amine curing agent, 6 parts of curing accelerator, 19 parts of tert-butyl acetate, and 5 parts of n-butanol.

[0117] (3) Component C includes: 10 parts isopropanol, 40 parts tert-butyl acetate, 43 parts butyl acetate, and 7 parts coupling agent.

[0118] 2. Preparation method of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0119] 3. Construction process of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0120] Comparative Example 1

[0121] 1. An epoxy heat-resistant and corrosion-resistant primer, composed of three components A, B, and C, with the following raw material mass ratios for each component:

[0122] (1) Component A includes: 0.1 parts of defoamer, 1 part of wetting and dispersing agent, 13 parts of environmentally friendly anti-rust pigment, 8 parts of functional filler, 16 parts of coloring pigment, 0.05 parts of antioxidant, 0.1 parts of ultraviolet absorber, 8 parts of primary ester solvent, 45 parts of bisphenol A epoxy resin, 5.75 parts of phenolic epoxy resin, and 3 parts of reactive diluent.

[0123] Among them, the environmentally friendly anti-rust pigment in component A is a compound of zinc molybdate, modified zinc phosphate, and polymeric anti-rust material in a weight ratio of 8:5:1; the functional filler is a compound of mica powder, talc powder, barium sulfate, alumina, and fumed silica in a weight ratio of 1:1.5:1:1.5:0.1; and the first ester solvent is a compound of butyl acetate and tert-butyl acetate in a weight ratio of 1:1.

[0124] (2) Component B includes: 43 parts of polyamide curing agent, 28 parts of modified amine curing agent, 5 parts of curing accelerator, 19 parts of tert-butyl acetate, and 5 parts of n-butanol.

[0125] (3) Component C includes: 10 parts isopropanol, 40 parts tert-butyl acetate, 43 parts butyl acetate, and 7 parts coupling agent.

[0126] 2. Preparation method of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0127] 3. Construction process of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0128] Comparative Example 2

[0129] 1. An epoxy heat-resistant and corrosion-resistant primer, composed of three components A, B, and C, with the following raw material mass ratios for each component:

[0130] (1) Component A includes: 36 parts of silicone-modified epoxy resin, 0.1 parts of defoamer, 1 part of wetting and dispersing agent, 13 parts of environmentally friendly anti-rust pigment, 8 parts of functional filler, 16 parts of coloring pigment, 0.05 parts of antioxidant, 0.1 parts of ultraviolet absorber, 8 parts of primary ester solvent, 14.75 parts of phenolic epoxy resin, and 3 parts of reactive diluent.

[0131] In component A, the environmentally friendly rust-preventive pigment is a compound of zinc molybdate, modified zinc phosphate, and polymeric rust inhibitor in a weight ratio of 8:5:1; the functional filler is a compound of mica powder, talc powder, barium sulfate, alumina, and fumed silica in a weight ratio of 1:1.5:1:1.5:0.1; and the first ester solvent is a compound of butyl acetate and tert-butyl acetate in a weight ratio of 1:1. The composition and preparation method of the organosilicon-modified epoxy resin in component A are the same as in Example 4.

[0132] (2) Component B includes: 43 parts of polyamide curing agent, 28 parts of modified amine curing agent, 5 parts of curing accelerator, 19 parts of tert-butyl acetate, and 5 parts of n-butanol.

[0133] (3) Component C includes: 10 parts isopropanol, 40 parts tert-butyl acetate, 43 parts butyl acetate, and 7 parts coupling agent.

[0134] 2. Preparation method of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0135] 3. Construction process of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0136] Comparative Example 3

[0137] 1. An organosilicon-modified epoxy heat-resistant and corrosion-resistant primer, composed of three components A, B, and C, with the following raw material mass ratios for each component:

[0138] (1) Component A includes: 26 parts of silicone-modified epoxy resin, 0.1 parts of defoamer, 1 part of wetting and dispersing agent, 13 parts of environmentally friendly anti-rust pigment, 8 parts of functional filler, 16 parts of coloring pigment, 0.05 parts of antioxidant, 0.1 parts of ultraviolet absorber, 8 parts of first ester solvent, 24.75 parts of bisphenol A type epoxy resin, and 3 parts of reactive diluent.

[0139] In component A, the environmentally friendly rust-preventive pigment is a compound of zinc molybdate, modified zinc phosphate, and polymeric rust inhibitor in a weight ratio of 8:5:1; the functional filler is a compound of mica powder, talc powder, barium sulfate, alumina, and fumed silica in a weight ratio of 1:1.5:1:1.5:0.1; and the first ester solvent is a compound of butyl acetate and tert-butyl acetate in a weight ratio of 1:1. The composition and preparation method of the organosilicon-modified epoxy resin in component A are the same as in Example 4.

[0140] (2) Component B includes: 43 parts of polyamide curing agent, 28 parts of modified amine curing agent, 5 parts of curing accelerator, 19 parts of tert-butyl acetate, and 5 parts of n-butanol.

[0141] (3) Component C includes: 10 parts isopropanol, 40 parts tert-butyl acetate, 43 parts butyl acetate, and 7 parts coupling agent.

[0142] 2. Preparation method of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0143] 3. Construction process of silicone-modified epoxy heat-resistant and anti-corrosion primer: same as in Example 1.

[0144] The coating films of Examples 1-4 and Comparative Examples 1-3 were subjected to comprehensive performance tests. The test standards are shown in Table 1, and the test results are shown in Tables 2 to 7. The comprehensive performance includes coating film appearance, state in container, surface drying time, pencil hardness, wet adhesion, dry adhesion, flexibility, impact resistance, high and low temperature impact resistance, heat resistance, damp heat resistance, salt spray corrosion, and filiform corrosion.

[0145] Table 1. Methods for Comprehensive Performance Testing

[0146] Test Project Test methods Paint film appearance Visual inspection State in the container Visual inspection Surface drying time GB / T1728-2020 Pencil hardness GB / T 6739-2022 Water resistance GB / T 1735-2009 Dry adhesion GB / T 1720-2020 flexibility GB / T 1731-2020 Impact resistance GB / T 1732-2020 High and low temperature shock GB / T 1731-2020 Heat resistance GB / T 1735-2009 Moist heat resistance GB / T 1740-2007 Salt spray corrosion GB / T 1771-2007 Filament corrosion GB / T 26323-2010

[0147] Table 2. Test data on paint film appearance, container condition, and surface drying time for Examples 1-4 and Comparative Examples 1-3.

[0148]

[0149] Table 3. Test data of pencil hardness, dry adhesion, and flexibility for Examples 1-4 and Comparative Examples 1-3.

[0150] Test Project Pencil hardness Dry adhesion flexibility Indicator Requirements ≥HB ≤2 levels ≤2mm Example 1 3H Level 2 1mm Example 2 3H Level 2 1mm Example 3 3H Level 2 1mm Example 4 3H Level 2 1mm Comparative Example 1 3H Level 2 3mm Comparative Example 2 2H Level 2 1mm Comparative Example 3 2H Level 2 1mm

[0151] Table 4 Impact resistance test data of Examples 1-4 and Comparative Examples 1-3

[0152]

[0153] Table 5. Water resistance test data of Examples 1-4 and Comparative Examples 1-3

[0154]

[0155] Table 6 Corrosion test data of Examples 1-4 and Comparative Examples 1-3

[0156]

[0157] Table 7. Heat resistance test data of Examples 1-4 and Comparative Examples 1-3

[0158]

[0159] It should be noted that in Examples 1-4, component A contains three resins: silicone-modified epoxy resin, bisphenol A type epoxy resin, and phenolic epoxy resin; and the total amount of the three resins is 50.75 parts. Compared with the examples, Comparative Examples 1, 2, and 3 use only two of the resins from the examples, and the total amount of the two resins is also 50.75 parts. Specifically, Comparative Example 1 uses only bisphenol A type epoxy resin and phenolic epoxy resin, Comparative Example 2 uses only silicone-modified epoxy resin and phenolic epoxy resin, and Comparative Example 3 uses only silicone-modified epoxy resin and bisphenol A type epoxy resin.

[0160] Based on the data in Tables 2 to 7, we can conclude that:

[0161] 1) After soaking at room temperature for 3 days, compared to the blistering of the silicone-modified epoxy heat-resistant and anti-corrosion primer films in Comparative Examples 1-3, the silicone-modified epoxy heat-resistant and anti-corrosion primer films in Examples 1-4 showed no delamination, no blistering, no peeling, only slight discoloration, and a 2-level decrease in pencil hardness, meeting the water resistance requirements. Therefore, the silicone-modified epoxy heat-resistant and anti-corrosion primer films prepared in these examples exhibit excellent water resistance.

[0162] 2) Compared to the minimum shaft diameter (3mm) of Comparative Example 1, the minimum shaft diameter of Examples 1-4 is significantly reduced, meeting the flexibility requirements. Therefore, the silicone-modified epoxy heat-resistant and corrosion-resistant primer films prepared in these examples exhibit excellent flexibility and good mechanical properties.

[0163] 3) Compared to the cracking of the paint film on tinplate under 50 kg·cm forward and reverse impacts in Comparative Examples 1-2, the paint film in Examples 1-4 showed no cracking or loss of adhesion under 50 kg·cm forward and reverse impacts, meeting the impact resistance requirements. Compared to the cracking of the paint film in Comparative Examples 1-3 after 24 cycles at -54℃ to 71℃, the paint film in Examples 1-4 showed no cracking, peeling, loss of adhesion, or other failure phenomena after 24 cycles at -54℃ to 71℃, meeting the high and low temperature impact resistance requirements. Therefore, the silicone-modified epoxy high-temperature resistant and anti-corrosion primer film prepared in these examples exhibits excellent impact resistance, and maintains excellent impact resistance even under high and low temperature environments.

[0164] 4) Compared to Comparative Examples 1-3, whose paint films peeled after 100 hours at 250℃, the paint films of Examples 1-4 remained intact and uniform with only slight gloss loss after 100 hours at 250℃, meeting the requirements for heat resistance. Compared to Comparative Examples 1-3, whose paint films suffered a comprehensive damage level of 3 or 4 after 2000 hours in a temperature and humidity control chamber at (47±1)℃ and (96±2)% humidity, the paint films of Examples 1-4 suffered a comprehensive damage level of 1 after 2000 hours in the same chamber, meeting the requirements for damp heat resistance. Therefore, the silicone-modified epoxy heat-resistant and anti-corrosion primer films prepared in these examples exhibit excellent heat resistance (250℃) and excellent damp heat resistance.

[0165] 5) Compared to Comparative Examples 1-2, whose paint films failed after 2000 hours of salt spray corrosion, Examples 1-4 showed no paint film failure after 2000 hours of salt spray corrosion, and no corrosion was observed at a distance of 3.2 mm from the scratch, meeting the requirements for salt spray corrosion resistance. Compared to Comparative Examples 1-2, whose paint films blistered after 30 days of filamentous corrosion, Examples 1-4 showed no blistering, corrosion, or other adhesion-reducing phenomena at a distance of more than 3.2 mm from the scratch after 30 days of filamentous corrosion, meeting the requirements for filamentous corrosion resistance. Therefore, the silicone-modified epoxy high-temperature resistant anti-corrosion primer films prepared in these examples exhibit excellent corrosion resistance.

[0166] 6) The pencil hardness and dry adhesion of Examples 1 to 4 all meet the index requirements. Therefore, it can be seen that the silicone-modified epoxy heat-resistant and anti-corrosion primer film prepared in the examples has high adhesion.

[0167] In summary, this invention modifies epoxy resin with organosilicon, combining the high temperature resistance of organosilicon resin with the high adhesion, high water resistance and thermal stability of epoxy resin. It also incorporates bisphenol A type epoxy resin and phenolic resin, and adds various non-toxic anti-rust pigments, additives, and VOC-exempt solvents. The resulting primer exhibits excellent environmental friendliness and can be used long-term in high-temperature environments of 250℃ with low film thickness (17-22μm). It also possesses excellent adhesion, mechanical properties, corrosion resistance, heat resistance, damp heat resistance, impact resistance, high and low temperature impact resistance, flexibility, and water resistance.

Claims

1. A silicone-modified epoxy heat-resistant and corrosion-resistant primer, characterized in that: The silicone-modified epoxy heat-resistant and corrosion-resistant primer comprises component A, component B, and component C; Component A includes silicone-modified epoxy resin, bisphenol A type epoxy resin, phenolic epoxy resin, reactive diluent, additives, pigments, fillers, and primary ester solvents; Component B includes polyamide curing agent, modified amine curing agent, curing accelerator, second ester solvent, and alcohol solvent; Component C includes second ester solvents, alcohol solvents, and coupling agents; Component A comprises, by weight, 100 parts: The components of component B, in units of 100 parts by total weight: The C component, in parts per 100 parts by total weight: The mass ratio of component A, component B and component C is 7~9:1:4~6; The silicone-modified epoxy resin is prepared by reacting the following raw materials. The phenylsiloxane resin is one or two of vinyl-terminated methylphenyl polysiloxane, polydimethylsiloxane, phenyl polytrimethylsiloxane, and phenyl-modified polysiloxane.

2. The silicone-modified epoxy heat-resistant and corrosion-resistant primer as described in claim 1, characterized in that: The mass ratio of component A, component B and component C is 7~8:1:4~5.

3. The silicone-modified epoxy heat-resistant and corrosion-resistant primer as described in claim 1, characterized in that: The organosilicon-modified epoxy resin is prepared by the following method: S1: Mix epoxy resin and xylene, and heat; S2: Add phenylsiloxane resin and color changer, then heat; S3: Add catalyst dropwise and heat to react; S4: Cool down, add butyl acetate, react to obtain organosilicon-modified epoxy resin.

4. The silicone-modified epoxy heat-resistant and corrosion-resistant primer as described in claim 3, characterized in that: In step S1, the temperature is 55~60℃; and / or In step S2, the temperature is 75~80℃; and / or In step S3, the temperature is 105~115℃, and the reaction time is 3~5h; and / or In step S4, the temperature is 70~90℃ and the reaction time is 2~3h.

5. The silicone-modified epoxy heat-resistant and corrosion-resistant primer as described in claim 1, characterized in that: In component A, The filler is two or more of the following: barium sulfate, modified talc, alumina, diatomaceous earth, fumed silica, mica powder, organobentonite, and conductive graphite; and / or The pigments include environmentally friendly anti-rust pigments and coloring pigments; and / or The additives include wetting and dispersing agents, defoamers, ultraviolet absorbers, and antioxidants; and / or The first ester solvent is at least one of ethyl acetate, butyl acetate, and tert-butyl acetate.

6. The silicone-modified epoxy heat-resistant and corrosion-resistant primer as described in claim 5, characterized in that: In component A, The environmentally friendly rust-preventive pigment is two or more of zinc molybdate, zinc phosphate, modified zinc phosphate, composite zinc phosphate, aluminum tripolyphosphate, and polymeric rust inhibitors; the coloring pigment is BASF's various color pigments; and / or The defoamer is one or both of modified polysiloxane or polyether solutions.

7. The silicone-modified epoxy heat-resistant and corrosion-resistant primer as described in claim 5 or 6, characterized in that: Component A was prepared by the following method: (1) The organosilicon modified epoxy resin, the first ester solvent, the wetting and dispersing agent, the defoamer, the environmentally friendly rust-preventing pigment, the coloring pigment, the antioxidant, the ultraviolet absorber, and the filler are mixed and stirred to obtain a mixed slurry; (2) Grind the mixed slurry to a fineness of ≤15μm, then add the bisphenol A type epoxy resin, phenolic epoxy resin and reactive diluent, disperse and mix evenly, and adjust the non-volatile content to 70~75% to obtain component A.

8. The silicone-modified epoxy heat-resistant and corrosion-resistant primer as described in claim 1, characterized in that: In components B and C The second ester solvent is one or more of ethyl acetate, butyl acetate, tert-butyl acetate, and propylene glycol methyl ether acetate; and / or The alcohol solvent is one or both of n-butanol and isopropanol.

9. A method for preparing an organosilicon-modified epoxy heat-resistant and corrosion-resistant primer as described in any one of claims 1 to 8, characterized in that... The method includes: The components of component A are mixed in parts by weight to obtain component A; the components of component B are mixed in parts by weight to obtain component B; the components of component C are mixed in parts by weight to obtain component C; after mixing components A, B and C in the specified amounts, an organosilicon-modified epoxy heat-resistant and anti-corrosion primer is prepared.

10. The application of an organosilicon-modified epoxy high-temperature resistant and anti-corrosion primer as described in any one of claims 1 to 8, or an organosilicon-modified epoxy high-temperature resistant and anti-corrosion primer prepared by the method described in claim 9, on the surface of a metal material.

11. The application as described in claim 10, characterized in that: The dry film thickness of the silicone-modified epoxy heat-resistant and corrosion-resistant primer on the surface of the metal material is 17~22μm.

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