Polishing-free super-adhesion water-based imitation copper paint and preparation method thereof

Abstract

The invention discloses polishing-free super-adhesion water-based imitation copper paint and a preparation method thereof, and belongs to the technical field of paint. The polishing-free super-adhesion water-based imitation copper paint is prepared from the following components in parts by mass: 40 to 45 parts of PUA resin, 5 to 6 parts of wetting penetrant, 18 to 22 parts of copper powder, 1 to 2 parts of bentonite, 8 to 10 parts of blocked isocyanate and 10 to 12 parts of deionized water. The preparation method comprises the following steps: firstly, mixing the PUA resin and the wetting and penetrating agent to obtain a premixed solution, adding the copper powder and the bentonite into the premixed solution, grinding and dispersing, then adding the deionized water and the blocked isocyanate into a dispersion system S2, and mixing to obtain the polishing-free super-adhesion water-based copper-imitating paint. The polishing-free super-adhesion water-based imitation copper paint provided by the invention can replace physical rust removal with chemical permeation, does not need to polish a base material, and can show super-strong adhesion on a metal plate.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and particularly relates to a polishing-free, super-adhesive water-based imitation copper paint and a preparation method thereof. Background Art

[0002] Among the many application fields of water-based paints, imitation copper paint has attracted much attention due to its unique decorative effect and broad application prospects. For example, in the fields of building exterior walls, metal products, furniture, etc., imitation copper paint can give the material surface a copper-like appearance, thereby enhancing the beauty and added value of the product.

[0003] However, there are some limitations in traditional water-based imitation copper paints. For example, it is usually necessary to perform pretreatments such as polishing on the substrate before construction to improve the adhesion of the paint film, which not only increases construction procedures and costs, but also may result in low construction efficiency. In addition, some water-based imitation copper paints still have room for improvement in terms of adhesion, weather resistance, corrosion resistance, etc., especially when facing complex and changeable outdoor environments. The performance stability of the paint film is difficult to meet the requirements of long-term use, and the paint surface may also be blackened and gray due to the oxidation of metal powder, affecting the quality of the paint film. Based on the deficiencies in the prior art, it is of great significance to develop a kind of non-polishing super-adhesive water-based imitation copper paint. Summary of the Invention

[0004] Based on the deficiencies of the prior art, the object of the present invention is to provide a polishing-free, super-adhesive water-based imitation copper paint and a preparation method thereof.

[0005] The first aspect of the present invention is to provide a polish-free, super-adhesive water-based imitation copper paint, which comprises the following components by weight: 40-45 parts of PUA resin, 5-6 parts of wetting and penetrating agent, 18-22 parts of copper powder, 1-2 parts of bentonite, 8-10 parts of blocked isocyanate, and 10-12 parts of deionized water; The wetting and penetrating agent comprises alkyl phosphate, perfluoropolyether carboxylate and polyether trisiloxane.

[0006] In some embodiments, the PUA resin is prepared by the following steps: (1) Mixing polytetramethylene ether glycol, isophorone diisocyanate, and dimethylol propionic acid to form a polyurethane prepolymer; (2) Add phosphate functional monomer and hydroxyethyl methacrylate to the polyurethane prepolymer and mix; (3) A neutralizing agent is added to the mixed system of step (2) and the mixture is mixed. Then, water is added while stirring to emulsify the mixture. After emulsification, the PUA resin is obtained.

[0007] In some embodiments, the mass ratio of polytetramethylene ether glycol, isophorone diisocyanate and dimethylol propionic acid is 8:4-5:1.

[0008] In some embodiments, the phosphate functional monomer is hydroxyalkyl acrylate phosphate or methacrylate phosphate; the amount of the phosphate functional monomer is 20-30% of the amount of isophorone diisocyanate; the mass ratio of the phosphate functional monomer to hydroxyethyl methacrylate is 4-6:5-7.

[0009] It should be noted that the phosphate group in the phosphate functional monomer can undergo acid-base dissociation at the metal interface to form phosphate ions, which covalently bond with metal atoms (Fe, Al, Zn, etc.) to form Fe-OP / Al-OP chemical bonds, thereby achieving super strong adhesion to the metal substrate.

[0010] In some embodiments, in step (1), the mixing temperature is 70-85°C and the mixing time is 3-4 h; in step (2), the mixing temperature is 50-60°C and the mixing time is 2-3 h; in step (3), the emulsification time is 50-70 min; the neutralizing agent is selected from at least one of triethylamine and dimethylethanolamine; and the amount of the neutralizing agent used is 6-8% of the amount of isophorone diisocyanate used.

[0011] In some embodiments, the wetting and penetrant agent is prepared by the following steps: First, mix the alcohol ether solvent and deionized water, and then add alkyl phosphate, perfluoropolyether carboxylate and polyether trisiloxane in sequence, with an interval of 8-12 minutes between each addition. After stirring, the wetting and penetrating agent is obtained.

[0012] It should be noted that the wetting and penetrating agent provided in this proposal creatively incorporates perfluoropolyether carboxylates, polyether trisiloxanes, and alkyl phosphates. The perfluoropolyether carboxylates possess strong fluorocarbon chains, capable of breaking down the water film on the metal oxide layer, allowing the coating to spread and penetrate into micron-sized pores. The polyether portion of the polyether trisiloxane is flexible, while the hydrophobic siloxane segments can reduce the surface tension of liquids and allow them to penetrate deep into the pores of the substrate, enveloping and carrying water vapor or oil within the pores, thereby removing it and exposing metal active sites. This facilitates the subsequent synergistic bonding of the alkyl phosphates and phosphate functional monomers to metal ions. The alkyl portion of the alkyl phosphates exhibits excellent compatibility with organic resins, enabling the resin to adhere better to the substrate surface. The electronegative phosphate groups can interact electrostatically with metal ions, enhancing the bonding between the metal and the paint. The synergistic effects of fluorine, which rapidly reduces substrate surface tension, silicon, which deeply expands pores, and phosphorus, which chemically bonds, achieve exceptional adhesion to polish-free substrates.

[0013] In some embodiments, the mass ratio of perfluoropolyether carboxylate, polyether trisiloxane, and alkyl phosphate is 5-7:2-4:1.

[0014] In some embodiments, the alcohol ether solvent is selected from at least one of ethylene glycol butyl ether and dipropylene glycol butyl ether; the amount of the alcohol ether solvent is 2-3 times the total amount of the perfluoropolyether carboxylate, polyether trisiloxane and alkyl phosphate.

[0015] The second aspect of the present invention is to provide a method for preparing a polish-free, super-adhesive water-based imitation copper paint, comprising the following steps: S1: Mix PUA resin and wetting and penetrating agent to obtain a premixed solution; S2: Add copper powder and bentonite to the premixed solution and grind and disperse; S3: Add deionized water and blocked isocyanate to the S2 dispersion system, and mix to obtain a polish-free, super-adhesive water-based imitation copper paint.

[0016] In some embodiments, the grinding in S2 is to a fineness of <20 μm.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The polishing-free, super-adhesive water-based imitation copper paint provided by the present invention uses perfluoropolyether carboxylate to break the water film of the metal oxide layer, polyether trisiloxane penetrates deep into the substrate to expose active metal sites, and potassium alkyl phosphate cooperates with phosphate to form a chelate bond. Chemical penetration replaces physical polishing to remove impurities, thereby achieving direct coating of oily and rusty substrates without the need to polish the substrate.

[0018] The present invention uses chemical bonding technology to enable the polishing-free super-adhesive water-based imitation copper paint to achieve ultra-high adhesion on substrates such as rusty metal plates and old copperware, thereby extending the service life of the metal and preventing the paint from falling off. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below with reference to the embodiments.

[0020] Example 1 A polish-free, super-adhesive water-based imitation copper paint comprises the following components, measured by mass: 43 parts of PUA resin, 6 parts of a wetting and penetrating agent, 20 parts of copper powder, 2 parts of bentonite, 9 parts of a blocked isocyanate, and 11 parts of deionized water; wherein the wetting and penetrating agent comprises an alkyl phosphate, a perfluoropolyether carboxylate, and a polyether trisiloxane.

[0021] Wherein, PUA resin is prepared by the following steps: (1) Polytetramethylene glycol, isophorone diisocyanate, and dimethylol propionic acid were mixed at a mass ratio of 8:5:1 at 80°C for 3 h to form a polyurethane prepolymer; (2) Adding hydroxyalkyl acrylate phosphate and hydroxyethyl methacrylate to the polyurethane prepolymer and mixing at 55°C for 3 h; wherein the amount of phosphate functional monomer used is 25% of the amount of isophorone diisocyanate used; the mass ratio of phosphate functional monomer to hydroxyethyl methacrylate is 5:6; (3) Triethylamine was added to the mixed system of step (2), and then water was added while stirring and emulsified for 60 minutes to obtain PUA resin after emulsification; wherein the amount of neutralizer used was 7% of the amount of isophorone diisocyanate used.

[0022] The wetting penetrant is prepared by the following steps: First, ethylene glycol butyl ether and deionized water were mixed, and then alkyl phosphate, perfluoropolyether carboxylate, and polyether trisiloxane were added in a mass ratio of 6:3:1 in sequence, with an interval of 10 minutes between each addition. After stirring, the wetting and penetrating agent was obtained; the amount of glycol ether solvent used was twice the total amount of perfluoropolyether carboxylate, polyether trisiloxane, and alkyl phosphate.

[0023] The above-mentioned non-polishing super-adhesive water-based imitation copper paint is prepared by the following preparation steps: S1: Mix PUA resin and wetting and penetrating agent to obtain a premixed solution; S2: Add copper powder and bentonite to the premixed solution and grind to a fineness of <20 μm; S3: Add deionized water and blocked isocyanate to the S2 dispersion system, and mix to obtain a polish-free, super-adhesive water-based imitation copper paint.

[0024] Example 2 The method is basically the same as Example 1, except that the method comprises the following components by mass: 45 parts of PUA resin, 6 parts of wetting and penetrating agent, 22 parts of copper powder, 2 parts of bentonite, 10 parts of blocked isocyanate, and 12 parts of deionized water.

[0025] Example 3 The method is basically the same as Example 1, except that the method comprises the following components in parts by mass: 40 parts of PUA resin, 5 parts of wetting and penetrating agent, 18 parts of copper powder, 1 part of bentonite, 8 parts of blocked isocyanate, and 10 parts of deionized water.

[0026] Example 4 It is basically the same as Example 1, except that: PUA resin is prepared by the following steps: (1) Polytetramethylene glycol, isophorone diisocyanate, and dimethylol propionic acid were mixed at a mass ratio of 8:4:1 at 70°C for 3 h to form a polyurethane prepolymer; (2) Phosphate methacrylate and hydroxyethyl methacrylate were added to the polyurethane prepolymer and mixed at 50°C for 2 h; the amount of phosphate functional monomer was 20% of the amount of isophorone diisocyanate; the mass ratio of phosphate functional monomer to hydroxyethyl methacrylate was 4:5; (3) Add dimethylethanolamine to the mixed system of step (2), and then add water while stirring and emulsify for 50 minutes. After emulsification, PUA resin is obtained; wherein the amount of neutralizer used is 6% of the amount of isophorone diisocyanate used.

[0027] The wetting penetrant is prepared by the following steps: First, dipropylene glycol butyl ether and deionized water were mixed, and then alkyl phosphate, perfluoropolyether carboxylate, and polyether trisiloxane were added in a mass ratio of 5:2:1 in sequence, with an interval of 8 minutes between each addition. After stirring, the wetting and penetrating agent was obtained; the amount of alcohol ether solvent used was twice the total amount of perfluoropolyether carboxylate, polyether trisiloxane, and alkyl phosphate.

[0028] Example 5 It is basically the same as Example 1, except that: PUA resin is prepared by the following steps: (1) Polytetramethylene glycol, isophorone diisocyanate, and dimethylol propionic acid were mixed at a mass ratio of 8:5:1 at 85°C for 4 h to form a polyurethane prepolymer; (2) Adding hydroxyalkyl acrylate phosphate and hydroxyethyl methacrylate to the polyurethane prepolymer and mixing at 60°C for 3 h; wherein the amount of phosphate functional monomer used is 30% of the amount of isophorone diisocyanate used; and the mass ratio of phosphate functional monomer to hydroxyethyl methacrylate is 6:7; (3) Triethylamine was added to the mixed system of step (2), and then water was added while stirring and emulsified for 70 minutes. After emulsification, PUA resin was obtained; wherein the amount of neutralizer used was 8% of the amount of isophorone diisocyanate used.

[0029] The wetting penetrant is prepared by the following steps: First, ethylene glycol butyl ether and deionized water were mixed, and then alkyl phosphate, perfluoropolyether carboxylate, and polyether trisiloxane were added in a mass ratio of 7:4:1 in sequence, with an interval of 12 minutes between each addition. After stirring, the wetting and penetrating agent was obtained; among them, the amount of glycol ether solvent used was 3 times the total amount of perfluoropolyether carboxylate, polyether trisiloxane, and alkyl phosphate.

[0030] Comparative Example 1 The process is basically the same as Example 1, except that no phosphate functional monomer is added to the PUA resin.

[0031] Comparative Example 2 The process is basically the same as Example 1, except that no wetting and penetrating agent is added.

[0032] Test Example 1 In order to prove that the polishing-free super-adhesive water-based imitation copper paint provided by the present invention can also have excellent adsorption capacity without polishing the substrate, the performance tests were carried out on the water-based imitation copper paints prepared in the above Examples 1-5 and Comparative Examples 1-2.

[0033] Examples 1-5 and Comparative Examples 1-2 were painted onto cast iron plates to a thickness of 25 ± 5 μm. The paint was dried at 140°C for 10 minutes and then tested for appearance, adhesion, impact strength, and pencil hardness. Adhesion was tested according to GB / T 9286-1998; impact strength was tested according to GB / T 1732-1993; and pencil hardness was tested according to GB / T 6739-96. The performance test results are shown in Table 1.

[0034] Table 1 From the test results in Table 1, it can be seen that the water-based imitation copper paints provided in the embodiments of the present invention have excellent decorative properties, adhesion, hardness and impact resistance. Since no phosphate functional monomer is added to the resin of Comparative Example 1, the adhesion is reduced. Comparative Example 2 does not use a wetting penetrant, which greatly reduces the ability to improve the bonding strength between the paint and the metal.

[0035] Test Example 2 To demonstrate the ability of the polish-free, super-adhesive water-based imitation copper paint provided by the present invention to achieve exceptional adhesion on unpolished substrates, the water-based imitation copper paint provided in Example 1 was applied to polished and unpolished cast iron plates for performance testing. Sample preparation and adhesion testing standards were the same as in Test Example 1. The performance test results are shown in Table 2.

[0036] Table 2 Combined with the data in Table 2, it can be seen that the performance of the polish-free water-based imitation copper paint provided by the present invention on the unpolished plate is consistent with that on the polished plate, indicating that the imitation copper paint can achieve chemical penetration instead of physical polishing, achieving polish-free super adhesion.

[0037] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A polish-free, super-adhesive water-based imitation copper paint, characterized in that: The components include the following by mass: 40-45 parts of PUA resin, 5-6 parts of wetting and penetrating agent, 18-22 parts of copper powder, 1-2 parts of bentonite, 8-10 parts of blocked isocyanate, and 10-12 parts of deionized water; The wetting and penetrating agent comprises alkyl phosphate, perfluoropolyether carboxylate and polyether trisiloxane.

2. The polish-free super-adhesive water-based imitation copper paint according to claim 1, characterized in that: The PUA resin is prepared by the following steps: Mixing polytetramethylene ether glycol, isophorone diisocyanate, and dimethylol propionic acid to form a polyurethane prepolymer; adding phosphate functional monomer and hydroxyethyl methacrylate to the polyurethane prepolymer and mixing; A neutralizing agent is added to the mixed system of step (2) and mixed, and then water is added while stirring to emulsify, and the PUA resin is obtained after emulsification.

3. The polish-free super-adhesive water-based imitation copper paint according to claim 2, characterized in that: The mass ratio of the polytetramethylene ether glycol, the isophorone diisocyanate and the dimethylol propionic acid is 8:4-5:

1.

4. The polish-free super-adhesive water-based imitation copper paint according to claim 2, characterized in that: The phosphate functional monomer is hydroxyalkyl acrylate phosphate or methacrylate phosphate; the amount of the phosphate functional monomer is 20-30% of the amount of the isophorone diisocyanate; the mass ratio of the phosphate functional monomer to the hydroxyethyl methacrylate is 4-6:5-7.

5. The polish-free super-adhesive water-based imitation copper paint according to claim 2, characterized in that: In the step (1), the mixing temperature is 70-85°C and the mixing time is 3-4 hours; in the step (2), the mixing temperature is 50-60°C and the mixing time is 2-3 hours; in the step (3), the emulsification time is 50-70 minutes; the neutralizing agent is selected from at least one of triethylamine and dimethylethanolamine; the amount of the neutralizing agent used is 6-8% of the amount of the isophorone diisocyanate used.

6. The polish-free super-adhesive water-based imitation copper paint according to claim 1, characterized in that: The wetting and penetrating agent is prepared by the following steps: First, the alcohol ether solvent and deionized water are mixed, and then the alkyl phosphate, the perfluoropolyether carboxylate and the polyether trisiloxane are added in sequence, with an interval of 8-12 minutes between each addition. After stirring, the wetting and penetrating agent is obtained.

7. The polish-free, super-adhesive water-based copper-like paint according to claim 6, characterized in that: The mass ratio of the perfluoropolyether carboxylate, the polyether trisiloxane and the alkyl phosphate is 5-7:2-4:

1.

8. The polish-free, super-adhesive water-based copper-like paint according to claim 6, characterized in that: The alcohol ether solvent is selected from at least one of ethylene glycol butyl ether and dipropylene glycol butyl ether; the amount of the alcohol ether solvent is 2-3 times the total amount of the perfluoropolyether carboxylate, the polyether trisiloxane and the alkyl phosphate.

9. A method for preparing the polish-free super-adhesive water-based imitation copper paint according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Mix PUA resin and wetting and penetrating agent to obtain a premixed solution; S2: adding copper powder and bentonite to the premixed solution and grinding and dispersing; S3: Deionized water and blocked isocyanate are added to the S2 dispersion system, and the mixture is mixed to obtain the polish-free, super-adhesive water-based imitation copper paint.

10. The preparation method according to claim 9, characterized in that In S2, the powder is ground to a fineness of <20 μm.

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