A high-thickness film anti-sagging epoxy primer and preparation method thereof

Abstract

The invention discloses a high-thickness film anti-sagging epoxy primer, which is composed of component A and component B; by weight, the components of component A are: 18-26 parts of epoxy resin, 0.5-3 parts of bentonite, 0.5-1.5 parts of fumed silica, 0.5-part of polyamide wax, 55-70 parts of zinc powder, and 10-20 parts of solvent A; by weight, the components of component B are: 64-74 parts of curing agent, 25-35 parts of solvent B, and 1-2 parts of curing accelerator. The high-thickness film anti-sagging epoxy primer prepared by the technical solution of the present invention has strong bonding with a steel substrate, high adhesion on the surface of the steel substrate, and the coating formed after film coating has excellent strength and corrosion resistance.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a high-thickness film anti-sagging epoxy primer and a preparation method thereof. Background Art

[0002] Steel is easily oxidized and corroded in humid air, which can cause steel structure products (such as containers, steel pipes, bridges, offshore platforms, ships, etc.) to corrode and rust, seriously affecting their safety and service life. Heavy-duty anti-corrosion coatings are mainly used for corrosion protection of steel. The existing heavy-duty anti-corrosion coatings on the market are mainly represented by zinc-containing coatings such as epoxy zinc-rich coatings. The anti-corrosion principle is to use the electrochemical reaction of metallic zinc to carry out anti-corrosion protection, that is, to use metallic zinc instead of iron to corrode and consume. However, the existing epoxy zinc-rich paint has poor anti-sagging performance and low adhesion. It is easy to fall off after being applied on the surface of steel structure products. In addition, it dries slowly, takes a long time to construct, and has low construction efficiency. Summary of the invention

[0003] In view of the problems and shortcomings in the prior art, the purpose of the present invention is to provide a high-thickness anti-sagging epoxy primer and a preparation method thereof.

[0004] To achieve the purpose of the invention, the technical solution adopted by the present invention is as follows:

[0005] The first aspect of the present invention provides a high-thickness anti-sagging epoxy primer, which consists of a component A and a component B; in parts by weight, the components of the component A are: 18-26 parts of epoxy resin, 0.5-3 parts of bentonite, 0.5-1.5 parts of fumed silica, 0.5-2 parts of polyamide wax, 55-70 parts of zinc powder, and 10-20 parts of solvent A; in parts by weight, the components of the component B are: 64-74 parts of a curing agent, 25-35 parts of a solvent B, and 1-2 parts of a curing accelerator.

[0006] According to the above-mentioned high-thickness anti-sagging epoxy primer, preferably, the mass ratio of component A to component B is 10-14:1; more preferably, the mass ratio of component A to component B is 12:1.

[0007] According to the above-mentioned high-thickness anti-sagging epoxy primer, preferably, the epoxy resin is E20 epoxy resin and / or E44 epoxy resin.

[0008] According to the above-mentioned high-thickness anti-sagging epoxy primer, preferably, the epoxy resin consists of E20 epoxy resin and E44 epoxy resin, and the mass ratio of E20 epoxy resin to E44 epoxy resin is 10:1.

[0009] According to the above-mentioned high-thickness anti-sagging epoxy primer, preferably, the curing agent is a polyamide curing agent; more preferably, the curing agent is a 650 polyamide curing agent.

[0010] According to the above-mentioned high-thickness anti-sagging epoxy primer, preferably, the curing accelerator is DMP-30.

[0011] According to the above-mentioned high-thickness film anti-sagging epoxy primer, preferably, the bentonite is organic bentonite.

[0012] According to the above-mentioned high-thickness anti-sagging epoxy primer, preferably, the fumed silica is R-972 fumed silica; and the polyamide wax is 3300 polyamide wax.

[0013] According to the above-mentioned high-thickness anti-sagging epoxy primer, preferably, by weight, the components of component A are: 22 parts of epoxy resin, 1 part of bentonite, 1 part of fumed silica, 1 part of polyamide wax, 60 parts of zinc powder, and 15 parts of solvent A; by weight, the components of component B are: 74 parts of curing agent, 29 parts of solvent B, and 1 part of curing accelerator.

[0014] According to the above-mentioned high-thickness anti-sagging epoxy primer, preferably, the solvent A is composed of xylene and n-butanol in a mass ratio of 1-3:1; more preferably, the solvent A is composed of xylene and n-butanol in a mass ratio of 2:1.

[0015] According to the above-mentioned high-thickness film anti-sagging epoxy primer, preferably, the solvent B is composed of xylene and n-butanol in a mass ratio of 2-3:1-2, and the solvent B is composed of xylene and n-butanol in a mass ratio of 20:9.

[0016] The second aspect of the present invention provides a method for preparing the high-thickness anti-sagging epoxy primer described in the first aspect, comprising the following steps:

[0017] (1) Preparation of component A: Add epoxy resin to solvent A and mix evenly; then add bentonite and disperse evenly at high speed; then add fumed silica and polyamide wax and mix evenly; finally add zinc powder and mix evenly to obtain component A;

[0018] (2) Preparation of Component B: Add curing agent and curing accelerator to solvent B and mix well to obtain Component B.

[0019] The third aspect of the present invention provides a method for using the high-thickness anti-sagging epoxy primer described in the first aspect above, which is to mix the component A and the component B in a mass ratio of 12:1, and then coat the mixture on the surface of a steel substrate product for corrosion protection of the steel substrate product.

[0020] Compared with the prior art, the present invention has the following positive and beneficial effects:

[0021] (1) The high-thickness anti-sagging epoxy primer of the present invention contains a polyamide curing agent and a DMP-30 curing accelerator. The addition of the polyamide curing agent and the DMP-30 curing accelerator increases the reaction rate of the curing reaction and shortens the drying time of the epoxy primer. The prepared high-thickness anti-sagging epoxy primer can be completely dried within 12 hours after coating. Compared with the existing commercially available epoxy zinc-rich paint, the drying time is shortened by half, which greatly improves the construction efficiency. Moreover, the polyamide curing agent and the DMP-30 curing accelerator can form a highly networked cross-linked structure with components such as epoxy resin, thereby improving the strength and corrosion resistance of the coating formed after the epoxy primer is dried.

[0022] (2) The high-thickness anti-sagging epoxy primer prepared by the present invention has a strong bonding force with the steel substrate and a high adhesion force on the surface of the steel substrate, which can reach 8.5 MPa and is not easy to fall off.

[0023] (3) The high-thickness anti-sagging epoxy primer of the present invention contains organic bentonite, fumed silica and polyamide wax. The quaternary ammonium hydrocarbon chain between the montmorillonite layers in the organic bentonite can be bridged by hydrogen bonds with the hydroxyl groups of n-butanol and fumed silica in the solvent to obtain effective solvation, thereby expanding and dispersing the interlayer to form a thixotropic gel, which can effectively prevent zinc powder precipitation and improve the storage stability of the epoxy primer; moreover, polyamide wax is a completely swollen paste, the swollen structure has high strength and good heat resistance, and only needs to be stirred and dispersed at room temperature to exert excellent anti-settling and anti-sagging performance. Therefore, the epoxy primer prepared by the compounding of organic bentonite, fumed silica and polyamide wax has excellent anti-settling and anti-sagging performance, and its anti-sagging performance is ≥200μm, and the storage stability is high.

[0024] (4) The high-thickness anti-sagging epoxy primer of the present invention can achieve a dry film thickness of up to 200 μm in a single construction, thereby improving construction efficiency. Moreover, the dry film coating after construction has an impact resistance of 50 cm and a salt spray resistance of ≥ 500 h. It has excellent strength and corrosion resistance and can be used for surface coating of steel substrates such as containers, steel pipes, bridges, offshore platforms, and ships, thereby effectively improving its corrosion resistance and greatly improving its service life and safety of use. DETAILED DESCRIPTION

[0025] The following detailed descriptions are all exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the art to which the present invention belongs. It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context otherwise clearly indicates, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, components and / or combinations thereof. The experimental methods in the following examples where specific conditions are not specified are all conventional techniques in the art, or according to the conditions recommended by the manufacturer; the reagents or instruments used where the manufacturer is not specified are all conventional products that can be obtained commercially.

[0026] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0027] Example 1: Screening of epoxy resin

[0028] In order to study the effect of epoxy resin type on the performance of the prepared high-thickness anti-sagging epoxy primer, the present invention carried out Examples 1-1 to 1-3. The contents of Examples 1-1 to 1-3 are as follows:

[0029] Example 1-1:

[0030] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. In parts by weight, the components of component A are composed of: 22 parts of epoxy resin, 1 part of organic bentonite, 1 part of fumed silica, 1 part of polyamide wax, 60 parts of zinc powder, and 15 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin in a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol in a mass ratio of 2:1. In parts by weight, the components of component B are composed of: 70 parts of 650 polyamide curing agent, 29 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol in a mass ratio of 20:9.

[0031] The specific steps of the preparation method of the above-mentioned high-thickness film anti-sagging epoxy primer are:

[0032] (1) Preparation of Component A: Add epoxy resin to solvent A and mix well at a stirring speed of 800 rpm; then add organic bentonite and disperse at a high speed of 1500 rpm for 30 minutes; then add fumed silica and polyamide wax and mix well; finally add zinc powder and mix well to obtain Component A;

[0033] (2) Preparation of Component B: Add 650 polyamide curing agent and DMP-30 curing accelerator to solvent B, and stir and mix at a stirring speed of 500 rpm to obtain Component B.

[0034] The method of using the high-thickness anti-sagging epoxy primer is: evenly mix component A and component B and apply them on the surface of the steel substrate product.

[0035] Embodiment 1-2:

[0036] The content of Example 1-2 is substantially the same as that of Example 1-1, except that in Component A, the epoxy resin is E20 epoxy resin.

[0037] Embodiment 1-3:

[0038] The content of Example 1-3 is substantially the same as that of Example 1-1, except that in Component A, the epoxy resin is E44 epoxy resin.

[0039] The performance of the high-thickness anti-sagging epoxy primers prepared in Examples 1-1 to 1-3 was tested, and the test results are shown in Table 1.

[0040] Among them, the solid content is tested in accordance with GB / T1725 (the standard requirement is: solid content ≥70wt%), the drying time is tested in accordance with GB / T1728 (the standard requirement is: surface drying time ≤4h, actual drying time ≤24h), the adhesion is tested in accordance with GB / T5210 (the standard requirement is: adhesion ≥3MPa), the impact resistance is tested in accordance with GB / T1732 (the standard requirement is: impact resistance ≥45cm), the salt spray resistance is tested in accordance with GB / T1771 (the standard requirement is: salt spray resistance ≥200h), and the anti-sagging performance is tested in accordance with GB / T9264 (the standard requirement is: anti-sagging performance ≥150μm).

[0041] Table 1 Effect of epoxy resin types on the performance of high-thickness anti-sagging epoxy primer of the present invention

[0042]

[0043] It can be seen from Table 1 that when E44 epoxy resin is used alone to prepare high-film anti-sagging epoxy primer, the salt spray resistance of the dry film coating of the high-film anti-sagging epoxy primer reaches 800h, but the anti-sagging performance of the high-film anti-sagging epoxy primer is only 150μm, and the drying time is long (actual drying requires 24h), and the dry film coating formed after drying is brittle and has poor impact resistance; when E20 epoxy resin is used alone to prepare high-film anti-sagging epoxy primer, the high-film anti-sagging epoxy primer has good anti-sagging performance, and the dry film coating formed after drying has good toughness and strong impact resistance, but the adhesion and salt spray resistance of the high-film anti-sagging epoxy primer are poor. When E20 epoxy resin and E44 epoxy resin are mixed in a mass ratio of 10:1, the prepared high-thickness anti-sagging epoxy primer has high adhesion, good anti-sagging performance, and short drying time. Moreover, the dry film coating formed after drying has good impact resistance and salt spray resistance.

[0044] Example 2: Screening of anti-sagging agents

[0045] In order to study the effect of the type of anti-sagging agent on the performance of the prepared high-thickness anti-sagging epoxy primer, the present invention carried out Examples 2-1 to 2-4. The contents of Examples 2-1 to 2-4 are as follows:

[0046] Example 2-1:

[0047] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. In parts by weight, the components of component A are composed of: 22 parts of epoxy resin, 3 parts of organic bentonite, 60 parts of zinc powder, and 15 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. In parts by weight, the components of component B are composed of: 70 parts of 650 polyamide curing agent, 29 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0048] The specific steps of the preparation method of the above-mentioned high-thickness film anti-sagging epoxy primer are:

[0049] (1) Preparation of Component A: Add epoxy resin to solvent A and mix well at a stirring speed of 800 rpm; then add organic bentonite and disperse at a high speed of 1500 rpm for 30 minutes; finally add zinc powder and mix well to obtain Component A;

[0050] (2) Preparation of Component B: Add 650 polyamide curing agent and DMP-30 curing accelerator to solvent B, and stir and mix at a stirring speed of 500 rpm to obtain Component B.

[0051] Example 2-2:

[0052] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. In parts by weight, the components of component A are composed of: 22 parts of epoxy resin, 3 parts of fumed silica, 60 parts of zinc powder, and 15 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. In parts by weight, the components of component B are composed of: 70 parts of 650 polyamide curing agent, 29 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0053] The specific steps of the preparation method of the above-mentioned high-thickness film anti-sagging epoxy primer are:

[0054] (1) Preparation of Component A: Add epoxy resin to solvent A and mix well at a stirring speed of 800 rpm; then add fumed silica and mix well, then add zinc powder and mix well to obtain Component A;

[0055] (2) Preparation of Component B: Add 650 polyamide curing agent and DMP-30 curing accelerator to solvent B, and stir and mix at a stirring speed of 500 rpm to obtain Component B.

[0056] Embodiment 2-3:

[0057] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. By weight, the components of component A are composed of: 22 parts of epoxy resin, 3 parts of polyamide wax, 60 parts of zinc powder, and 15 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. By weight, the components of component B are composed of: 70 parts of 650 polyamide curing agent, 29 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0058] The specific steps of the preparation method of the above-mentioned high-thickness film anti-sagging epoxy primer are:

[0059] (1) Preparation of Component A: Add epoxy resin to solvent A and mix well at a stirring speed of 800 rpm; then add polyamide wax and mix well, then add zinc powder and mix well to obtain Component A;

[0060] (2) Preparation of Component B: Add 650 polyamide curing agent and DMP-30 curing accelerator to solvent B, and stir and mix at a stirring speed of 500 rpm to obtain Component B.

[0061] Embodiment 2-4:

[0062] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. By weight, the components of component A are composed of: 22 parts of epoxy resin, 60 parts of zinc powder, 15 parts of solvent A, and 3 parts of auxiliary agent, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. By weight, the components of component B are composed of: 70 parts of 650 polyamide curing agent, 29 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0063] The specific steps of the preparation method of the above-mentioned high-thickness film anti-sagging epoxy primer are:

[0064] (1) Preparation of Component A: Add epoxy resin to solvent A and mix well at a stirring speed of 800 rpm; then add zinc powder and mix well to obtain Component A;

[0065] (2) Preparation of Component B: Add 650 polyamide curing agent and DMP-30 curing accelerator to solvent B, and stir and mix at a stirring speed of 500 rpm to obtain Component B.

[0066] The performance of the high-thickness anti-sagging epoxy primers prepared in Examples 2-1 to 2-4 was tested, and the test results are shown in Table 2.

[0067] Table 2 Effect of the type of anti-sagging agent on the performance of the high-thickness anti-sagging epoxy primer of the present invention

[0068]

[0069] As shown in Table 2, when no anti-sagging agent is added, the anti-sagging performance of the prepared epoxy primer is poor, which can only reach 30μm, and it is impossible to prepare a thick paste type coating; when organic bentonite is used alone as an anti-sagging agent, the prepared high-thick film anti-sagging epoxy primer has a good anti-settling effect, but poor anti-sagging performance, which is only 100μm; when fumed silica is used alone as an anti-sagging agent, the prepared high-thick film anti-sagging epoxy primer has better anti-sagging performance than organic bentonite, but the anti-sagging performance is When polyamide wax is used alone as an anti-sagging agent, the prepared high-thick film anti-sagging epoxy primer has good anti-sagging performance (can reach 200 μm), which is the same as the effect of compounding organic bentonite, fumed silica and polyamide wax in a mass ratio of 1:1:1 as an anti-sagging agent, but its adhesion to the steel substrate is poor, and the price of polyamide wax is high. When polyamide wax is used alone as an anti-sagging agent, the cost of the high-thick film anti-sagging epoxy primer is high. Therefore, considering the cost and performance, the anti-sagging agent is preferably compounded with organic bentonite, fumed silica and polyamide wax in a mass ratio of 1:1:1.

[0070] Example 3: Study on the effect of curing agent on the performance of high-thickness anti-sagging epoxy primer

[0071] In order to study the effect of the curing agent on the performance of the prepared high-thickness anti-sagging epoxy primer, the present invention carried out Examples 3-1 and 3-2. The contents of Examples 3-1 and 3-2 are as follows:

[0072] Example 3-1:

[0073] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. By weight, the components of component A are composed of: 22 parts of epoxy resin, 1 part of organic bentonite, 1 part of fumed silica, 1 part of polyamide wax, 60 parts of zinc powder, and 15 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. By weight, the components of component B are composed of: 29 parts of solvent B and 71 parts of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0074] The specific steps of the preparation method of the above-mentioned high-thickness film anti-sagging epoxy primer are:

[0075] (1) Preparation of Component A: Add epoxy resin to solvent A and mix well at a stirring speed of 800 rpm; then add organic bentonite and disperse at a high speed of 1500 rpm for 30 minutes; then add fumed silica and polyamide wax and mix well; finally add zinc powder and mix well to obtain Component A;

[0076] (2) Preparation of Component B: Add DMP-30 curing accelerator to solvent B, and stir at 500 rpm to mix evenly to obtain Component B.

[0077] Example 3-2:

[0078] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. In parts by weight, the components of component A are composed of: 22 parts of epoxy resin, 1 part of organic bentonite, 1 part of fumed silica, 1 part of polyamide wax, 60 parts of zinc powder, and 15 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin in a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol in a mass ratio of 2:1. In parts by weight, the components of component B are composed of: 71 parts of 650 polyamide curing agent, 29 parts of solvent B, and solvent B is a mixture of xylene and n-butanol in a mass ratio of 20:9.

[0079] The specific steps of the preparation method of the above-mentioned high-thickness film anti-sagging epoxy primer are:

[0080] (1) Preparation of Component A: Add epoxy resin to solvent A and mix well at a stirring speed of 800 rpm; then add organic bentonite and disperse at a high speed of 1500 rpm for 30 minutes; then add fumed silica and polyamide wax and mix well; finally add zinc powder and mix well to obtain Component A;

[0081] (2) Preparation of Component B: Add 650 g of polyamide curing agent to solvent B, and stir at 500 rpm to mix evenly to obtain Component B.

[0082] The performance of the high-thickness anti-sagging epoxy primer prepared in Example 3-1 to Example 3-2 was tested, and the test results are shown in Table 3.

[0083] Table 3 Effect of curing agent on the performance of high-thickness anti-sagging epoxy primer of the present invention

[0084]

[0085] It can be seen from Table 3 that when the high-film anti-sagging epoxy primer component B contains only 650 polyamide curing agent, the prepared high-film anti-sagging epoxy primer has a long drying time and low construction efficiency, but the dry film coating formed after drying has good impact resistance and salt spray resistance; when the high-film anti-sagging epoxy primer component B contains only DMP-30 curing accelerator, the prepared high-film anti-sagging epoxy primer has a short drying time and high construction efficiency, but the dry film coating formed after drying is brittle, and the impact resistance and salt spray resistance are poor; when 650 polyamide curing agent and DMP-30 curing accelerator are added to the high-film anti-sagging epoxy primer component B at the same time, the prepared high-film anti-sagging epoxy primer has a moderate drying time, and the dry film coating formed after drying has strong adhesion (reaching 8.5MPa), high impact resistance (50cm) and salt spray resistance (520h). At the same time, for comparison, the present invention also made an epoxy primer without curing agent (that is, the epoxy primer only has component A and does not contain component B). After the epoxy primer is applied, it cannot form a dry paint film and cannot play the role of impact resistance and corrosion resistance. Therefore, when 650 polyamide curing agent and DMP-30 curing accelerator are added to component B at the same time, the high-thickness anti-sagging epoxy primer prepared has the best performance.

[0086] Example 4: Zinc powder dosage study experiment

[0087] In order to study the effect of zinc powder addition on the performance of the high-thickness anti-sagging epoxy primer of the present invention, the present invention conducted research on Examples 4-1 to 4-4. The contents of Examples 4-1 to 4-4 are as follows:

[0088] Example 4-1:

[0089] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. In parts by weight, the components of component A are composed of: 22 parts of epoxy resin, 1 part of organic bentonite, 1 part of fumed silica, 1 part of polyamide wax, 50 parts of zinc powder, and 25 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. In terms of mass percentage, the components of component B are composed of: 70 parts of 650 polyamide curing agent, 29 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0090] The preparation method of the high-thickness anti-sagging epoxy primer is the same as that of Example 1-1.

[0091] Example 4-2:

[0092] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. In parts by weight, the components of component A are composed of: 22 parts of epoxy resin, 1 part of organic bentonite, 1 part of fumed silica, 1 part of polyamide wax, 55 parts of zinc powder, and 20 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. In terms of mass percentage, the components of component B are composed of: 70 parts of 650 polyamide curing agent, 29 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0093] The preparation method of the high-thickness anti-sagging epoxy primer is the same as that of Example 1-1.

[0094] Example 4-3:

[0095] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. In parts by weight, the components of component A are composed of: 22 parts of epoxy resin, 1 part of organic bentonite, 1 part of fumed silica, 1 part of polyamide wax, 65 parts of zinc powder, and 10 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. In terms of mass percentage, the components of component B are composed of: 70 parts of 650 polyamide curing agent, 29 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0096] The preparation method of the high-thickness anti-sagging epoxy primer is the same as that of Example 1-1.

[0097] Example 4-4:

[0098] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. In parts by weight, the components of component A are composed of: 22 parts of epoxy resin, 1 part of organic bentonite, 1 part of fumed silica, 1 part of polyamide wax, 70 parts of zinc powder, and 5 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin in a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol in a mass ratio of 2:1. In terms of mass percentage, the components of component B are composed of: 70 parts of 650 polyamide curing agent, 29 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol in a mass ratio of 20:9.

[0099] The preparation method of the high-thickness anti-sagging epoxy primer is the same as that of Example 1-1.

[0100] The performance of the high-thickness anti-sagging epoxy primers prepared in Examples 4-1 to 4-4 was tested, and the test results are shown in Table 4.

[0101] Table 4 Effect of curing agent on the performance of high-thickness anti-sagging epoxy primer of the present invention

[0102]

[0103] It can be seen from Table 4 that with the increase of zinc powder dosage, the salt spray resistance of the high-thickness anti-sagging epoxy primer gradually increases, but the impact resistance decreases. Considering the drying time, adhesion, impact resistance and anti-sagging performance of the high-thickness anti-sagging epoxy primer, the zinc powder dosage is preferably 60 parts.

[0104] Example 5: Performance comparison between the high-thickness anti-sagging epoxy primer of the present invention and the existing epoxy zinc-rich primer

[0105] In order to demonstrate the performance of the high-thickness anti-sagging epoxy primer of the present invention, the present invention takes the high-thickness anti-sagging epoxy primer prepared in Example 1-1 as an example, and compares the performance with two existing commercially available epoxy zinc-rich primers. The results are shown in Table 5.

[0106] Table 5 Performance comparison results of the high-thickness anti-sagging epoxy primer of the present invention and the existing epoxy zinc-rich primer

[0107]

[0108] As can be seen from Table 5, the high-thickness anti-sagging epoxy primer prepared by the present invention has a short drying time and strong adhesion. The impact resistance, salt spray resistance and anti-sagging performance of the dry film coating formed after drying are better than those of the existing commercially available epoxy zinc-rich primers.

[0109] Embodiment 6:

[0110] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. By weight, the components of component A are composed of: 22 parts of epoxy resin, 2 parts of organic bentonite, 0.5 parts of fumed silica, 0.5 parts of polyamide wax, 55 parts of zinc powder, and 20 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. By weight, the components of component B are composed of: 66 parts of 650 polyamide curing agent, 32 parts of solvent B, and 2 parts of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0111] The preparation method and use method of the above-mentioned high-thickness anti-sagging epoxy primer are the same as those in Example 1-1.

[0112] Embodiment 7:

[0113] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. By weight, the components of component A are composed of: 18 parts of epoxy resin, 0.5 parts of organic bentonite, 1.0 parts of fumed silica, 0.5 parts of polyamide wax, 70 parts of zinc powder, and 10 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. By weight, the components of component B are composed of: 64 parts of 650 polyamide curing agent, 35 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0114] The preparation method and use method of the above-mentioned high-thickness anti-sagging epoxy primer are the same as those in Example 1-1.

[0115] Embodiment 8:

[0116] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. By weight, the components of component A are composed of: 26 parts of epoxy resin, 3 parts of organic bentonite, 0.5 parts of fumed silica, 0.5 parts of polyamide wax, 55 parts of zinc powder, and 15 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. By weight, the components of component B are composed of: 74 parts of 650 polyamide curing agent, 25 parts of solvent B, and 1 part of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0117] The preparation method and use method of the above-mentioned high-thickness anti-sagging epoxy primer are the same as those in Example 1-1.

[0118] Embodiment 9:

[0119] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. By weight, the components of component A are composed of: 20 parts of epoxy resin, 0.5 parts of organic bentonite, 1.5 parts of fumed silica, 2 parts of polyamide wax, 65 parts of zinc powder, and 11 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. By weight, the components of component B are composed of: 68 parts of 650 polyamide curing agent, 30 parts of solvent B, and 2 parts of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0120] The preparation method and use method of the above-mentioned high-thickness anti-sagging epoxy primer are the same as those in Example 1-1.

[0121] Embodiment 10:

[0122] A high-thickness anti-sagging epoxy primer, the high-thickness anti-sagging epoxy primer is composed of component A and component B, and the mass ratio of component A to component B is 12:1. In parts by weight, the components of component A are composed of: 20 parts of epoxy resin, 1 part of organic bentonite, 1 part of fumed silica, 1 part of polyamide wax, 60 parts of zinc powder, and 17 parts of solvent A, wherein the epoxy resin is a mixture of E20 epoxy resin and E44 epoxy resin at a mass ratio of 10:1, and the solvent A is a mixture of xylene and n-butanol at a mass ratio of 2:1. In parts by weight, the components of component B are composed of: 65 parts of 650 polyamide curing agent, 33 parts of solvent B, and 2 parts of DMP-30 curing accelerator, and solvent B is a mixture of xylene and n-butanol at a mass ratio of 20:9.

[0123] The preparation method and use method of the above-mentioned high-thickness anti-sagging epoxy primer are the same as those in Example 1-1.

[0124] Embodiment 11:

[0125] The content of Example 11 is substantially the same as that of Example 1-1, except that the mass ratio of component A to component B in the high-thickness anti-sagging epoxy primer is 10:1.

[0126] Embodiment 12:

[0127] The content of Example 12 is basically the same as that of Example 1-1, except that the mass ratio of component A to component B in the high-thickness anti-sagging epoxy primer is 14:1.

[0128] Embodiment 13:

[0129] The content of Example 13 is substantially the same as that of Example 1-1, except that solvent A and solvent B are both prepared by mixing xylene and n-butanol in a mass ratio of 2:1.

[0130] The high-thickness anti-sagging epoxy primers prepared in Examples 6 to 13 were subjected to performance testing, and the test results are shown in Table 6.

[0131] Table 6 Performance test results of high-thickness anti-sagging epoxy primers prepared in Example 6-Example 13

[0132]

[0133] The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in other forms. Any technician familiar with the profession may use the above technical content as inspiration to make changes or modifications. This is an equivalent embodiment of equivalent changes. However, any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical concept of the present invention still fall within the scope of protection of the claims of the present invention.

Claims

1. A high-thickness anti-sagging epoxy primer, characterized in that: The invention comprises component A and component B; the components of component A are as follows by weight: 22 parts of epoxy resin, 1 part of bentonite, 1 part of fumed silica, 1 part of polyamide wax, 60 parts of zinc powder and 15 parts of solvent A; the components of component B are as follows by weight: 74 parts of curing agent, 29 parts of solvent B and 1 part of curing accelerator; the mass ratio of component A to component B is 10-14:1; the epoxy resin is composed of E20 epoxy resin and E44 epoxy resin, and the mass ratio of E20 epoxy resin to E44 epoxy resin is 10:1; the curing agent is a polyamide curing agent, the curing accelerator is DMP 30, and the bentonite is an organic bentonite; the solvent A is composed of xylene and n-butanol in a mass ratio of 1-3:1, and the solvent B is composed of xylene and n-butanol in a mass ratio of 2-3:1-2.

2. The method for preparing the high-thickness anti-sagging epoxy primer according to claim 1, characterized in that: The following steps are involved: (1) Preparation of component A: Add epoxy resin to solvent A and mix evenly; then add bentonite and disperse evenly at high speed; then add fumed silica and polyamide wax and mix evenly; finally add zinc powder and mix evenly to obtain component A; (2) Preparation of Component B: Add curing agent and curing accelerator to solvent B and mix well to obtain Component B.

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