Low-surface-treatment anticorrosive paint for rusty coating and preparation method of low-surface-treatment anticorrosive paint

Abstract

The invention discloses a low-surface-treatment anti-corrosion coating for coating with rust and a preparation method of the low-surface-treatment anti-corrosion coating. The low-surface-treatment anticorrosive paint for coating with rust comprises the following components in parts by weight: 30-40 parts of epoxy resin; 10 to 20 parts of zinc phosphate; 5 to 10 parts of pigment; 25-35 parts of a filler; 10 to 20 parts of a solvent; 0.1 to 1.0 part of an organic silicon leveling agent; 0.1 to 1.0 part of an organic silicon defoaming agent; and 0.5-2.0 parts of a wetting dispersant. The anticorrosive paint disclosed by the invention can be effectively coated on a rusty and low-surface-treated metal surface, so that the construction efficiency is improved, the cost is reduced, and the service life of the metal can be effectively prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of anti-corrosion coatings, and in particular to a low-surface-treated anti-corrosion coating for rust-coating and a preparation method thereof. Background Art

[0002] In the field of metal corrosion protection, the application of anti-corrosion coatings is a common and effective protective measure. However, in actual applications, many metal surfaces are rusted. Traditional anti-corrosion coatings require strict rust removal on the metal surface before painting, which is not only time-consuming and labor-intensive, but also increases the construction cost and may cause certain damage to the metal surface. Rust-resistant paint is a primer for protecting metals. It can be directly applied on metal surfaces where rust removal is not complete or cannot be completely removed. According to the product performance requirements of the HG / T 4564-2013 industry standard "Epoxy Coatings with Low Surface Treatment Tolerance", it is of great practical significance to develop a coating that can still have good anti-corrosion properties, physical properties, original paint properties, construction properties, paint film properties and other properties under rust and low surface treatment conditions. Summary of the invention

[0003] The purpose of the present invention is to provide a low surface treatment anti-corrosion coating for rust coating and a preparation method thereof, wherein the anti-corrosion coating can be effectively coated on a metal surface with rust and low surface treatment, thereby improving construction efficiency and reducing costs. The prepared coating has good anti-corrosion performance, physical properties, original paint properties, construction performance and paint film properties, and can effectively extend the service life of the metal.

[0004] To achieve the above object, the present invention adopts the following technical solution: In a first aspect, the present invention provides a low surface treatment anti-corrosion coating for rust coating, which comprises the following components in parts by weight: 30-40 parts of epoxy resin; 10-20 parts of zinc phosphate; Pigment 5-10 parts; 25-35 parts of filler; 10-20 parts of solvent; 0.1-1.0 part of silicone leveling agent; 0.1-1.0 part of silicone defoamer; Wetting and dispersing agent 0.5-2.0 parts.

[0005] In the above-mentioned low surface treatment anti-corrosion coating for rust coating, the epoxy resin is any one of E51, E20 and E44.

[0006] In the above-mentioned anti-corrosion coating for low surface treatment of rust-coating, the pigment is titanium dioxide; The filler is talc and barium sulfate, preferably talc and barium sulfate in a weight ratio of 15: (10-20); The particle size of the filler is 1000-2500 meshes.

[0007] In the above-mentioned low surface treatment anti-corrosion coating for rust coating, the solvent is xylene and n-butyl acetate, preferably xylene and n-butyl acetate in a weight ratio of (5-6):5.

[0008] In the above-mentioned low-surface-treated anti-corrosion coating for rust-coating, the organosilicon leveling agent is a polyether-modified polyoxydimethylsiloxane solution, preferably BYK-306.

[0009] In the above-mentioned low surface treatment anti-corrosion coating for rust coating, the organosilicon defoamer is a polysiloxane solution, preferably BYK-141.

[0010] In the above-mentioned low surface treatment anti-corrosion coating for rust coating, the wetting and dispersing agent is a copolymer solution having an acidic group, preferably BYK-110.

[0011] In a second aspect, the present invention provides a method for preparing a low surface treatment anti-corrosion coating for rust coating as described in any one of the above, comprising the following steps: (1) mixing the epoxy resin and the solvent and stirring them evenly; (2) adding the zinc phosphate, the pigment, the filler, the organosilicon leveling agent, the organosilicon defoaming agent and the wetting and dispersing agent to the mixture obtained in step (1) in sequence while stirring, and continuing to stir; (3) Grinding the mixture obtained in step (2) to obtain the low surface treatment anti-corrosion coating for rust coating.

[0012] In the above-mentioned method for preparing a low-surface-treated anticorrosive coating for rust-coating, in step (1), the rotation speed of the stirring step is 500 to 1000 rpm, and the stirring time is 30 minutes; In step (2), the rotation speed of the continued stirring step is 1000-2000 rpm, and the stirring time is 30 minutes.

[0013] In the above-mentioned method for preparing a low-surface-treated anti-corrosion coating for rust-coating, in step (3), the fineness of the grinding step is ≤60 μm.

[0014] The present invention has the following beneficial effects: (1) The anti-corrosion coating of the present invention can be applied on metal surfaces with rust and low surface treatment, which greatly reduces the construction difficulty and cost. The coating has good anti-rust performance and can effectively extend the service life of the metal. The formula is reasonable, the preparation process is simple, and it is easy to realize industrial production.

[0015] (2) The present invention uses epoxy resin as a film-forming substance, zinc phosphate as an anti-rust pigment, talcum powder and barium sulfate as fillers. By comparing different types of leveling agents, defoamers and dispersants, it is found that when leveling agent BYK-306, defoamer BYK-141 and wetting dispersant BYK-110 are used, the comprehensive performance such as anti-corrosion performance, physical properties, original paint performance, construction performance, and paint film performance is the best. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a process flow chart for preparing a low surface treatment anti-corrosion coating for rust coating. DETAILED DESCRIPTION

[0017] "Low surface treatment coating" is a direct translation from "Surface-Tolerant Coating". According to industry practice, it is also called "low surface treatment coating". This coating can tolerate a lower surface treatment cleanliness level. As described in the background technology, it is currently urgent to develop a coating that can still have good anti-corrosion performance, physical properties, original paint properties, construction performance, paint film performance and other properties under rust and low surface treatment conditions. As a kind of low surface treatment coating, rust-resistant coating refers to a tolerant coating that can be used for rusty surfaces.

[0018] In the present invention, rust refers to a small amount of relatively firmly attached "residual rust" or newly formed "flash rust" allowed after surface treatment; residual rust mainly refers to relatively firmly attached oxide scale and rust and other corrosion products remaining due to incomplete rust removal, and the thickness of residual rust after surface treatment can generally reach 40-50 microns; flash rust mainly refers to new rust products generated in a short period of time on the surface of carbon steel with relatively high reaction activity due to the presence of water / moisture after rust removal by high-pressure water jetting or wet sandblasting, and the thickness is generally not too high, about 20 microns.

[0019] In the first part, the present invention provides a low-surface-treated anti-corrosion coating for rust-coating, which includes the following components in parts by weight: 30 to 40 parts of epoxy resin; 10 to 20 parts of zinc phosphate; 5 to 10 parts of pigment, 25 to 35 parts of filler; 10 to 20 parts of solvent; 0.1 to 1.0 parts of silicone leveling agent; 0.1 to 1.0 parts of silicone defoaming agent; and 0.5 to 2.0 parts of wetting and dispersing agent.

[0020] According to the present invention, preferably, the low surface treatment anti-corrosion coating for rust coating comprises the following components in parts by weight: 35-40 parts of epoxy resin; 15-20 parts of zinc phosphate; 5-10 parts of pigment; 25-30 parts of filler; 10-15 parts of solvent; 0.4-0.8 parts of silicone leveling agent; 0.6-0.8 parts of silicone defoaming agent; and 1.0-1.5 parts of wetting and dispersing agent.

[0021] According to the present invention, more preferably, the low surface treatment anti-corrosion coating for rust coating comprises the following components in parts by weight: 40 parts of epoxy resin; 15 parts of zinc phosphate; 7 parts of pigment, 25 parts of filler; 10 parts of solvent; 0.7 parts of silicone leveling agent; 0.8 parts of silicone defoaming agent; and 1.5 parts of wetting and dispersing agent.

[0022] In some embodiments of the present invention, the epoxy resin is any one of E51, E20 and E44. Epoxy resin is a film-forming substance of primer, also known as base material. Epoxy resin is classified according to epoxy value, epoxy resin E51 represents an average epoxy value of 51 / 100, epoxy resin E44 represents an average epoxy value of 44 / 100, and E20 represents an average epoxy value of 20 / 100. For coatings with different uses and technical requirements, the choice of epoxy resin grades is also different.

[0023] In some embodiments of the present invention, the pigment is titanium dioxide (titanium dioxide), a white pigment.

[0024] In some embodiments of the present invention, the filler is talcum powder and barium sulfate, preferably talcum powder and barium sulfate in a weight ratio of 15: (10-20), including but not limited to talcum powder and barium sulfate in a weight ratio of 15:10, 15:15 or 15:20; wherein the particle size of the filler is 1000-2500 mesh, including but not limited to 1250 mesh. Talc and barium sulfate are used as fillers. Talc increases the hardness, filling property, and polishability of the paint and reduces the cost; barium sulfate can reduce the cost and improve the acid resistance, alkali resistance, and adhesion of the paint; the combination of the two is more conducive to performance improvement.

[0025] In some embodiments of the present invention, the solvent is xylene and n-butyl acetate, preferably xylene and n-butyl acetate in a weight ratio of (5-6):5, including but not limited to 6:5 and 5:5.

[0026] In some embodiments of the present invention, the organic silicon leveling agent is a polyether modified polyoxydimethylsiloxane solution, preferably BYK-306. The leveling agent can promote the coating to form a flat, smooth and uniform coating film during the drying and film-forming process. Whether the coating can achieve a flat and smooth property is called leveling. BYK-306, as a leveling agent, can strongly reduce surface tension and has a very strong leveling effect.

[0027] In some embodiments of the present invention, the organosilicon defoamer is a polysiloxane solution, preferably BYK-141. The defoamer can reduce the surface tension of the system, so that the original foam is reduced or eliminated. BYK-141 is used as a defoamer to eliminate microbubbles, and has a strong defoaming function and can quickly eliminate bubbles.

[0028] In some embodiments of the present invention, the wetting and dispersing agent is a copolymer solution having an acidic group, preferably BYK-110. The wetting and dispersing agent has wetting and dispersing capabilities, and affects the viscosity and fineness of the coating. BYK-110, as a dispersant, can quickly reduce the viscosity of the base material and increase the fineness of the filler.

[0029] In a second aspect, the present invention provides a method for preparing a low surface treatment anti-corrosion coating for rust coating as described in any one of the above, comprising the following steps: (1) mixing the epoxy resin and the solvent and stirring them evenly; (2) adding the zinc phosphate, the pigment, the filler, the organosilicon leveling agent, the organosilicon defoaming agent and the wetting and dispersing agent to the mixture obtained in step (1) in sequence while stirring, and continuing to stir; (3) Grinding the mixture obtained in step (2) to obtain the low surface treatment anti-corrosion coating for rust coating.

[0030] In some embodiments of the present invention, in step (1), the rotation speed of the stirring step is 500-1000 rpm (e.g., 500 r / min), and the stirring time is 30 minutes; in step (2), the rotation speed of the continued stirring step is 1000-2000 rpm (e.g., 1500 r / min), and the stirring time is 30 minutes.

[0031] In some embodiments of the present invention, in step (3), the fineness of the grinding step is ≤60 μm, such as 60 μm.

[0032] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0033] The methods used in the following examples, unless otherwise specified, are all conventional methods, carried out according to the techniques or conditions described in the literature in the art or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial sources.

[0034] The dispersants BYK-110, BYK-163, defoamers BYK-141, BYK-052, BYK-088 and leveling agents BYK-306, BYK-358, BYK-310, BYK-333, BYK-378 in the following examples are all products of BYK of Germany.

[0035] Example 1 1. Formula The low surface treatment anti-corrosion coating for rust coating in this embodiment is composed of the following components in parts by weight: Film-forming substance [epoxy resin E51] 30 parts; Anti-rust pigment [zinc phosphate] 15 parts; Pigment [titanium dioxide (Chemours R706)] 7 parts; Filler [1250 mesh talc] 15 parts; Filler [1250 mesh barium sulfate] 20 parts; Solvent [xylene] 6 parts; Solvent [butyl acetate] 5 parts; Dispersant [BYK-110] 1 part; Defoaming agent [BYK-141] 0.5 parts; Leveling agent [BYK-306] 0.5 parts.

[0036] 2. Preparation method Step 1: Add 30 parts of epoxy resin, a film-forming substance, and 11 parts of solvent [xylene, butyl acetate] into a stirring kettle, and stir at a speed of 500 r / min for 30 minutes until the mixture is evenly stirred; Step 2: While stirring, add 15 parts of anti-rust pigment [zinc phosphate], 7 parts of pigment [titanium dioxide], 35 parts of filler [1250 mesh talc, 1250 mesh barium sulfate], 1 part of dispersant [BYK-110], 0.5 parts of defoamer [BYK-141], and 0.5 parts of leveling agent [BYK-306] in sequence, and stir at a speed of 1500r / min for 60min; Step 3: Grind the stirred paint until the fineness reaches 60μm; Step 4: Filter and package to obtain the finished product.

[0037] Example 2 The low surface treatment anti-corrosion coating for rust coating provided in this embodiment is composed of the following components in parts by weight: Film-forming substance [epoxy resin E51] 35 parts; Anti-rust pigment [zinc phosphate] 15 parts; Pigment [titanium dioxide (Chemours R706)] 7 parts; Filler [1250 mesh talc] 15 parts; Filler [1250 mesh barium sulfate] 15 parts; Solvent [xylene] 6 parts; Solvent [butyl acetate] 5 parts; Dispersant [BYK-110] 1.0 part; Defoaming agent [BYK-141] 0.6 parts; Leveling agent [BYK-306] 0.4 parts.

[0038] The preparation method is the same as Example 1.

[0039] Example 3 The low surface treatment anti-corrosion coating for rust coating provided in this embodiment is composed of the following components in parts by weight: Film-forming substance [epoxy resin E51] 40 parts; Anti-rust pigment [zinc phosphate] 15 parts; Pigment [titanium dioxide (Chemours R706)] 7 parts; Filler [1250 mesh talc] 15 parts; Filler [1250 mesh barium sulfate] 10 parts; Solvent [xylene] 5 parts; Solvent [butyl acetate] 5 parts; Dispersant [BYK-110] 1.5 parts; Defoaming agent [BYK-141] 0.8 parts; Leveling agent [BYK-306] 0.7 parts.

[0040] The preparation method is the same as Example 1.

[0041] Comparative Example 1 The formula is the same as Example 3, except that the defoamer is replaced by BYK-052 (a polymer defoamer that does not contain silicone).

[0042] Comparative Example 2 The formula is the same as that of Example 3, except that the defoamer is replaced by BYK-088.

[0043] Comparative Example 3 The formula is the same as that of Example 3, except that the leveling agent is replaced by BYK-358.

[0044] Comparative Example 4 The formula is the same as that of Example 3, except that the leveling agent is replaced by BYK-310.

[0045] Comparative Example 5 The formula is the same as that of Example 3, except that the leveling agent is replaced by BYK-333.

[0046] Comparative Example 6 The formula is the same as that of Example 3, except that the dispersant is replaced by BYK-163.

[0047] Test Case The performance of the anti-corrosion coating prepared in the above examples was tested, and the results are shown in Table 1.

[0048] The test methods for each project are as follows: Adhesion: GB / T 5210; Salt spray resistance: GB / T 1771; Flexibility: GB / T 1731; Impact resistance: GB / T 1732; Water resistance: GB / T 1733; Fineness: GB / T 1724; Leveling: JB / T3998; Surface drying time: GB / T 1728; Drying time: GB / T 1728; Bubbles: visual inspection.

[0049] Table 1 Test results of anticorrosion coating performance

[0050] Table 2 Test results of anticorrosion coating performance

[0051] It can be seen from Examples 1-3 that the anti-corrosion coating of the present invention has a fineness of 60 μm, a surface drying time of less than 3 h, a practical drying time of less than 24 h, a leveling property ≥ Grade 8, no bubbles, an adhesion ≥ 9 MPA, a salt spray resistance ≥ 900 h, an impact resistance of 50 cm, a flexibility of 1 mm, and a water resistance ≥ 480 h, and all performance indicators meet the relevant requirements.

[0052] It can be seen from Example 3 and Comparative Examples 1-2 that the type of defoamer not only affects the bubbles in the anti-corrosion coating, but also affects the leveling, adhesion and salt resistance of the anti-corrosion coating. The preferred defoamer of the present invention is BYK-141.

[0053] It can be seen from Example 3 and Comparative Examples 3-5 that the type of leveling agent not only affects the leveling property of the anti-corrosion coating, but also affects performance indicators such as bubbles and salt spray resistance. The preferred leveling agent of the present invention is BYK-306.

[0054] It can be seen from Example 3 and Comparative Example 6 that the type of dispersant not only affects the leveling property of the anti-corrosion coating, but also affects the adhesion and salt spray resistance. The preferred dispersant of the present invention is BYK-110.

[0055] The present invention has been described in detail above. For those skilled in the art, without departing from the purpose and scope of the present invention, can implement the present invention in a wider range under equivalent parameters, concentrations and conditions. Although the present invention provides specific embodiments, it should be understood that the present invention can be further improved. In a word, according to the principle of the present invention, the application is intended to include any changes, uses or improvements to the present invention, including departing from the disclosed scope in the application and the changes made with conventional techniques known in the art.

Claims

1. An anti-corrosion coating with low surface treatment for rust-coating, characterized in that: In parts by weight, it includes the following components: 30-40 parts of epoxy resin; 10-20 parts of zinc phosphate; Pigment 5-10 parts; 25-35 parts of filler; 10-20 parts of solvent; 0.1-1.0 part of silicone leveling agent; 0.1-1.0 part of silicone defoamer; Wetting and dispersing agent 0.5-2.0 parts.

2. The low surface treatment anti-corrosion coating for rust-coating according to claim 1, characterized in that: The epoxy resin is any one of E51, E20 and E44.

3. The low surface treatment anti-corrosion coating for rust-coating according to any one of claims 1-2, characterized in that: The pigment is titanium dioxide; The filler is talc and barium sulfate, preferably talc and barium sulfate in a weight ratio of 15: (10-20); The particle size of the filler is 1000-2500 meshes.

4. The low surface treatment anti-corrosion coating for rust-coating according to any one of claims 1 to 3, characterized in that: The solvent is xylene and n-butyl acetate, preferably the weight ratio of xylene to n-butyl acetate is (5-6):

5.

5. The low surface treatment anti-corrosion coating for rust-coating according to any one of claims 1 to 4, characterized in that: The organosilicon leveling agent is a polyether-modified polyoxydimethylsiloxane solution, preferably BYK-306.

6. The low surface treatment anti-corrosion coating for rust-coating according to any one of claims 1 to 5, characterized in that: The organosilicon defoamer is a polysiloxane solution, preferably BYK-141.

7. The low surface treatment anti-corrosion coating for rust-coating according to any one of claims 1 to 6, characterized in that: The wetting and dispersing agent is a copolymer solution having an acidic group, preferably BYK-110.

8. The method for preparing the low surface treatment anticorrosive coating for rust coating according to any one of claims 1 to 7, comprising the following steps: (1) mixing the epoxy resin and the solvent and stirring them evenly; (2) adding the zinc phosphate, the pigment, the filler, the organosilicon leveling agent, the organosilicon defoaming agent and the wetting and dispersing agent to the mixture obtained in step (1) in sequence while stirring, and continuing to stir; (3) Grinding the mixture obtained in step (2) to obtain the low surface treatment anti-corrosion coating for rust coating.

9. The method for preparing the low surface treatment anticorrosive coating for rust coating according to claim 8, characterized in that: In step (1), the rotation speed of the stirring step is 500 to 1000 rpm, and the stirring time is 30 minutes; In step (2), the rotation speed of the continued stirring step is 1000-2000 rpm, and the stirring time is 30 minutes.

10. The method for preparing a low surface treatment anti-corrosion coating for rust coating according to any one of claims 8 to 9, characterized in that: In step (3), the fineness of the grinding step is ≤60 μm.

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