Water-based acrylate copolymer type rust converting agent and preparation method thereof

Abstract

The invention discloses a water-based acrylate copolymer type rust converting agent, which comprises the following raw materials by weight: 10-40% of ethyl hexyl acrylate; 1-20% of methacrylic acid; 0-20% of acrylic acid; 0.25 to 0.5 percent of a peroxide initiator; 1-3% of an anionic emulsifier; 0.5%-1.5% of a nonionic emulsifier; 1-3% of a coalescing agent; and the balance of water. According to the water-based acrylate copolymer type rust converting agent, carboxyl groups in methacrylic acid and acrylic acid units react with rust to generate a compact polymeric membrane, and the polymeric membrane can be firmly attached to the surface of an iron matrix; a polymeric membrane generated after the water-based acrylate copolymer type iron rust converting agent containing the methacrylic acid unit and the ethyl hexyl acrylate unit is applied has excellent waterproof performance, water and moisture can be prevented from making contact with a rusted iron matrix continuously, and the iron matrix is prevented from being rusted continuously; and the rust transforming agent has no corrosion to a concrete matrix.

Description

Technical Field

[0001] The present application relates to the technical field of coating compositions, and in particular to a water-based acrylate copolymer type rust conversion agent and a preparation method thereof. Background Art

[0002] Rust-resistant paint can be applied with rust, that is, it is directly sprayed on the rusted metal surface and reacts chemically with the rust to form a dense protective film, thereby achieving excellent metal anti-corrosion performance and preventing the metal material from rusting again.

[0003] Water-based rust converter can be obtained by copolymerization of butyl acrylate and acrylic acid. Although the copolymer has the effect of rust conversion, due to the good hydrophilicity of acrylic acid monomer, the formed conversion film is not hydrophobic enough and has poor salt spray resistance, so it is not effective in some humid environments. In addition, due to the strong acidity of acrylic acid monomer in the converter, it will cause certain corrosion to the concrete substrate it contacts. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a water-based acrylate copolymer type rust conversion agent, the technical solution adopted includes:

[0005] A water-based acrylic copolymer type rust conversion agent, the raw materials of which include, by weight percentage:

[0006]

[0007]

[0008] A technical solution adopted by an embodiment of the present invention to solve the technical problem is: the anionic emulsifier is polyoxyethylene ether ammonium sulfate.

[0009] A technical solution adopted by an embodiment of the present invention to solve the technical problem is: the non-ionic emulsifier is fatty alcohol polyoxyethylene ether.

[0010] A technical solution adopted by an embodiment of the present invention to solve the technical problem is: the peroxide initiator is ammonium persulfate or potassium persulfate.

[0011] The present application also proposes a method for preparing the above-mentioned water-based acrylate copolymer type rust conversion agent, which is characterized by comprising:

[0012] Step 1, weigh the raw materials according to the formula;

[0013] Step 2, dissolving the peroxide initiator in water to prepare a 10 wt % initiator solution;

[0014] Step 3, dissolving anionic emulsifier and nonionic emulsifier in water to prepare a 5wt% emulsifier solution, wherein the mass ratio of anionic emulsifier to nonionic emulsifier in the emulsifier solution is 2:1, retaining a portion, and adding ethylhexyl acrylate, methacrylic acid, and acrylic acid monomers into the remaining emulsifier solution to disperse and obtain a monomer emulsion;

[0015] Step 4: Add the retained emulsifier solution into the reaction container, heat it to 80-85°C, add part of the monomer emulsion and initiator solution and stir evenly, then gradually drop the remaining monomer emulsion and initiator solution into the reaction container, stir and react at about 80-85°C for about 4-5h, then heat it to 90-95°C, continue to react for 1-2h under vacuum conditions and then cool it down. After cooling to 40-50°C, add a film-forming aid and stir evenly to obtain a water-based acrylate copolymer type rust converter.

[0016] Beneficial effects of the present invention:

[0017] (1) The carboxyl groups of the methacrylic acid and acrylic acid units of the water-based acrylic copolymer type rust converter react with rust to form a dense polymer film that can firmly adhere to the surface of the iron substrate. At the same time, the polymer film formed after the application of the water-based acrylic copolymer type rust converter containing methacrylic acid units has excellent waterproof properties and can prevent water and moisture from continuing to contact the uncorroded iron substrate, thereby preventing the iron substrate from continuing to rust.

[0018] (2) The present application utilizes methacrylic acid to replace most or all of the acrylic acid monomers to generate a copolymer. The introduced methacrylic acid monomer has weaker acidity than acrylic acid due to the electron-donating property of the methyl group. After replacing most or all of the acrylic acid monomers, the acidity of the rust conversion agent can be reduced, thereby preventing the rust treatment agent from corroding the concrete matrix.

[0019] (3) In the present application, ethylhexyl acrylate monomer is introduced into the water-based acrylate copolymer type rust conversion agent. The ethylhexyl acrylate monomer has a relatively long hydrophobic side group, which can provide better hydrophobic properties to the copolymer, thereby improving the salt spray resistance of the rust conversion film, so that the neutral salt spray resistance test result of the polymer film generated after the application of the water-based acrylate copolymer type rust conversion agent can reach 144 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 This is a schematic diagram of the application of the water-based acrylate copolymer-type rust conversion agent prepared in Examples 1-3 of the present application on a rusty iron sheet. DETAILED DESCRIPTION

[0022] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0023] The terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art.

[0024] The present invention is further described in detail below in conjunction with specific examples and with reference to data. It should be understood that this embodiment is only for illustrating the present invention and is not intended to limit the scope of the present invention in any way.

[0025] In the following examples, various processes and methods not described in detail are conventional methods known in the art. The materials, reagents, devices, instruments, equipment, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources.

[0026] The raw materials of the water-based acrylate copolymer type rust conversion agent described in the present application include, by weight percentage:

[0027]

[0028]

[0029] Based on the above content, Examples 1-3 of the present application are proposed. The specific compositions of the raw materials of the water-based acrylate copolymer-type rust conversion agent in Examples 1-3 are shown in Table 1.

[0030] Table 1

[0031]

[0032] According to the contents recorded in Table 1, the raw materials of Examples 1-3 were used to prepare a water-based acrylate copolymer type rust conversion agent according to the following steps:

[0033] Step 1, weigh the raw materials according to the formula;

[0034] Step 2, dissolving the peroxide initiator in water to prepare a 10 wt % initiator solution;

[0035] Step 3, dissolving anionic emulsifier and nonionic emulsifier in water to prepare a 5wt% emulsifier solution, wherein the mass ratio of anionic emulsifier to nonionic emulsifier in the emulsifier solution is 2:1, retaining a portion of the emulsifier solution, adding ethylhexyl acrylate, methacrylic acid, and acrylic acid monomers into the remaining emulsifier solution to disperse, and obtaining a monomer emulsion;

[0036] Step 4: Add the retained emulsifier solution into the reaction container, heat it to 80°C, add part of the monomer emulsion and initiator solvent and stir evenly, then gradually drop the remaining monomer emulsion and initiator solution into the reaction container, stir and react at about 80°C for about 4h, heat it to 90°C, continue to react for 1h under vacuum conditions and then cool it down. After cooling to 40°C, add the film-forming aid and stir evenly to obtain a water-based acrylate copolymer type rust converter.

[0037] The water-based acrylate copolymer-type rust conversion agents prepared in Examples 1-3 are all in the form of emulsions, and no lumps are formed when stirred.

[0038] like Figure 1 As shown, the water-based acrylate copolymer rust conversion agent prepared in Example 1-3 was applied to a severely rusted (yellow) iron sheet at an amount of 100 g / ㎡. After being left for a period of time, a black polymer film layer was formed on the rusted iron sheet of Example 1-3;

[0039] The pH value of the water-based acrylate copolymer rust conversion agent prepared in Example 1 was tested according to GB / T 14518-1993. The test results are shown in Table 2.

[0040] The rusted iron sheet with a polymer film layer produced in Example 1 was subjected to a neutral salt spray test according to the method of GB / T1771-2007, and the test results are shown in Table 2; the coating adhesion test was carried out according to the standard of GB / T9286-2021, and the test results are shown in Table 2.

[0041] Table 2

[0042]

[0043] According to the test results in Table 2, the polymer film produced by coating the rusty iron sheet with the water-based acrylate copolymer type rust converter prepared in Example 1 has excellent adhesion to the iron substrate, and the neutral salt spray resistance can reach 144 hours, and has excellent neutral salt spray resistance. The pH value of the water-based acrylate copolymer type rust converter emulsion is 4.0, and there is no blistering, no powdering, no cracking, and no corrosion when it is coated on the concrete substrate.

[0044] Of course, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications and substitutions are all included in the scope defined by the claims of this application.

Claims

1. A water-based acrylate copolymer type rust conversion agent, characterized in that: The raw materials include by weight percentage: The balance is water.

2. The water-based acrylate copolymer type rust conversion agent according to claim 1, characterized in that: The anionic emulsifier is polyoxyethylene ether ammonium sulfate.

3. The water-based acrylate copolymer type rust conversion agent according to claim 1, characterized in that: The nonionic emulsifier is fatty alcohol polyoxyethylene ether.

4. The water-based acrylate copolymer type rust conversion agent according to claim 1, characterized in that: The peroxide initiator is ammonium persulfate or potassium persulfate.

5. A method for preparing the water-based acrylate copolymer type rust conversion agent according to claim 1, characterized in that: include: Step 1, weigh the raw materials according to the formula; Step 2, dissolving the peroxide initiator in water to prepare a 10 wt % initiator solution; Step 3, dissolving anionic emulsifier and nonionic emulsifier in water to prepare a 5wt% emulsifier solution, wherein the mass ratio of anionic emulsifier to nonionic emulsifier in the emulsifier solution is 2:1, retaining a portion, and adding ethylhexyl acrylate, methacrylic acid, and acrylic acid monomers into the remaining emulsifier solution to disperse and obtain a monomer emulsion; Step 4: Add the retained emulsifier solution into the reaction container, heat it to 80-85°C, add part of the monomer emulsion and initiator solution and stir evenly, then gradually drop the remaining monomer emulsion and initiator solution into the reaction container, stir and react at about 80-85°C for about 4-5h, then heat it to 90-95°C, continue to react for 1-2h under vacuum conditions and then cool it down. After cooling to 40-50°C, add a film-forming aid and stir evenly to obtain a water-based acrylate copolymer type rust converter.

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