Metal element coating based on high polymer material and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and discloses a high polymer material-based metal element coating and a preparation method thereof, the coating is formed by mixing raw materials such as an acrylic resin prepolymer and a modified silicon nitride filler, the coating can be cured through ultraviolet irradiation, and the coating can be used as a metal element coating. Wherein the modified silicon nitride filler is prepared by grafting a block high-molecular polymer on the surface of nano silicon nitride, and the block high-molecular polymer structure contains a large number of active alkenyl groups, so that an acrylic resin prepolymer can be subjected to in-situ graft polymerization on the surface of nano boron nitride in the subsequent coating photo-initiation curing process, and further, the surface of the nano boron nitride is modified. The nano boron nitride is uniformly dispersed in a coating formed by curing the coating, the heat conduction effect and strength of the coating are improved by utilizing the excellent heat conduction performance of the nano silicon nitride, and in addition, the block high-molecular polymer structure contains a large number of biphenyl structures with high stability, so that the rigidity of a molecular chain of the coating can be improved, and the heat conduction performance of the coating is improved. And thus, the high-temperature resistance of the coating is effectively enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and specifically relates to a coating for metal components based on polymer materials and a preparation method thereof. Background Art

[0002] Metal components play a crucial role in many industrial fields and daily life. However, metals themselves can chemically react with elements such as oxygen, phosphorus, and nitrogen in the air in a long-term high-temperature working environment, generating metal oxides and gradually falling off, causing metal corrosion. This corrosion phenomenon not only reduces the mechanical properties of metal components but may also lead to their failure, thus triggering a series of safety problems. In addition, metal components may also be damaged in various forms such as mechanical wear and chemical erosion during use. Therefore, by selecting an appropriate coating, excellent mechanical properties such as rust and corrosion resistance, hardness and wear resistance can be obtained on the surface of metal components. The coating forms a protective film to isolate the metal components from the external environment, thereby effectively preventing damages such as corrosion and wear.

[0003] With the rapid development of modern science and technology and the continuous improvement of industrial levels, metal components need to work under high-temperature conditions in many fields. For example, engine components, high-temperature pipelines, etc. in the fields of aerospace, automotive manufacturing, and power industry need to withstand extremely high temperatures. Therefore, the coatings for metal components also need to have the characteristic of high temperature resistance.

[0004] Existing polymer-type coatings, such as acrylic resin coatings, are prone to oxidation and peeling under high-temperature conditions, and thus lose the protective effect on metal components. Therefore, it is of great significance to develop a coating with high-temperature resistance. Summary of the Invention

[0005] In order to solve the problems mentioned in the background art, the purpose of the present invention is to provide a coating for metal components based on polymer materials and a preparation method thereof.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A preparation method of a coating for metal components based on polymer materials, wherein the coating for metal components comprises the following raw materials measured by weight parts: 46 - 52 parts of acrylic resin prepolymer; 1 - 3 parts of modified silicon nitride filler; 0.5 - 1 part of leveling agent; 0.3 - 0.5 part of photoinitiator; The preparation method of the coating for metal components comprises the following steps: First step, weigh each component raw material according to the weight parts and prepare the materials; Step 2: Add the acrylic resin prepolymer, modified silicon nitride filler, leveling agent and photoinitiator into a stirring kettle, start stirring, set the rotation speed to 200 - 400 r / min, mechanically stir for 30 - 60 min, then let it stand for 1 - 2 h, and discharge the material, then it's done.

[0007] As a further scheme of the present invention, the preparation method of the acrylic resin prepolymer is as follows: Add butyl acrylate, methyl methacrylate, and isobornyl acrylate into ethyl acetate, stir evenly, introduce nitrogen for protection, then raise the temperature to 60 - 70 °C, keep stirring for 20 - 30 min to form a uniform reaction solution, then add azobisisobutyronitrile into the reaction solution. After adding, further raise the temperature to 80 - 90 °C, continuously keep the temperature for polymerization for 3 - 6 h, then cool down and discharge the material, and the acrylic resin prepolymer can be obtained.

[0008] As a further scheme of the present invention, the mass ratio of butyl acrylate, methyl methacrylate, isobornyl acrylate, and azobisisobutyronitrile is 30 - 40:50 - 55:10 - 15:0.1 - 0.2.

[0009] As a further scheme of the present invention, the specific preparation method of the modified silicon nitride filler includes the following steps: Step S1: Ultrasonically disperse the dried nano - silicon nitride in an ethanol solution, then add a silane coupling agent to the formed dispersion. After adding, raise the temperature to 70 - 80 °C, reflux and react for 3 - 6 h, then centrifuge out the solid product, wash it, and dry it under vacuum to obtain the silicon nitride modifier; Step S2: Add the silicon nitride modifier into an N,N - dimethylformamide medium, ultrasonically disperse for 20 - 40 min to form a uniform dispersion, then add a block copolymer and tetrabutylammonium bromide to the dispersion. After adding, stir evenly, keep the temperature at 80 - 90 °C for 6 - 9 h, stop heating, cool down and discharge the material, and the modified silicon nitride filler can be obtained.

[0010] As a further scheme of the present invention, in step S1, the silane coupling agent is 3 - glycidoxypropyltrimethoxysilane or 3 - glycidoxypropyltriethoxysilane.

[0011] As a further scheme of the present invention, in step S2, the preparation method of the block copolymer is as follows: 5,5'-Diallyl-[1,1'-biphenyl]-2,2'-diol was added to dimethyl sulfoxide. After the addition, it was stirred and mixed evenly to form a homogeneous reaction solution. Nitrogen was introduced for protection. Then, allyl succinic anhydride was added to the reaction solution. After the addition, it was stirred at room temperature for 2-4 h. Then, a phase transfer catalyst was added to the reaction solution, and the temperature was raised to 120-130 °C, and the polymerization was continued under insulation for 16-24 h to obtain a block polymer.

[0012] As a further aspect of the present invention, the molar ratio of 5,5'-diallyl-[1,1'-biphenyl]-2,2'-diol to allyl succinic anhydride is 1:0.4-0.5.

[0013] As a further aspect of the present invention, the phase transfer catalyst is p-toluenesulfonic acid.

[0014] In the above technical solution, first, nano-silicon nitride was surface-modified with an epoxy group silane coupling agent to obtain a silicon nitride modifier with epoxy substituents on the surface.

[0015] Using 5,5'-diallyl-[1,1'-biphenyl]-2,2'-diol and allyl succinic anhydride as reactants, at room temperature, the hydroxyl substituents in the structure of 5,5'-diallyl-[1,1'-biphenyl]-2,2'-diol can undergo a ring-opening esterification reaction with allyl succinic anhydride to form an intermediate with active hydroxyl substituents and carboxyl substituents at both ends. Then, under the action of a phase transfer catalyst, the intermediate undergoes a self-polymerization reaction to obtain a block polymer with an alternating structure connected by ester bonds. By controlling the molar ratio of the reactants, the block polymer can have active hydroxyl substituents at its ends.

[0016] Finally, using tetrabutylammonium bromide as a catalyst, the epoxy substituents in the structure of the silicon nitride modifier are catalytically subjected to a ring-opening addition reaction with the active hydroxyl substituents at the ends of the block polymer to modify the block polymer on the surface of nano-silicon nitride to obtain a modified silicon nitride filler.

[0017] As a further aspect of the present invention, the defoamer is any one of BYK-333, BYK-310, or BYK-315N; the initiator is benzoin dimethyl ether.

[0018] A metal component coating based on a polymer material is prepared by the above preparation method.

[0019] The beneficial effects of the present invention: In the present invention, a modified silicon nitride filler is prepared by grafting a block polymer on the surface of nano-silicon nitride. Since a large number of active vinyl groups are contained in the structure of the block polymer, during the subsequent photo-initiated curing process of the coating, the acrylic resin prepolymer can be in-situ graft-polymerized on the surface of nano-boron nitride, and then the nano-boron nitride is uniformly dispersed in the coating formed by curing the coating. Utilizing the excellent thermal conductivity of nano-silicon nitride, a heat conduction path is constructed, which is beneficial to heat dissipation. Moreover, the uniformly dispersed nano-silicon nitride can also utilize its own advantages as a nano-material to enhance and modify the coating. On the other hand, a large number of biphenyl structures with strong stability are contained in the structure of the block polymer, which can improve the rigidity of the molecular chain of the coating, and thus effectively enhance the high-temperature resistance of the coating.

[0020] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is an infrared analysis test chart of the block polymer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0024] Embodiment 1, a metal component coating based on a polymer material, comprising the following raw materials measured by weight parts: 46 parts of acrylic resin prepolymer; 1 part of modified silicon nitride filler; 0.5 part of leveling agent BYK-333; 0.3 part of photoinitiator benzoin dimethyl ether; The preparation method of the metal component coating comprises the following steps: First step, weigh each component raw material according to the weight parts and prepare the materials; Step 2: Add the acrylic resin prepolymer, modified silicon nitride filler, leveling agent BYK-333, and photoinitiator benzoin dimethyl ether into a stirring kettle, start stirring, set the rotation speed to 200 r / min, stir mechanically for 60 min, let stand for 1 h, and then discharge the material, and that's it.

[0025] Example 2, a metal component coating based on polymer materials, comprising the following raw materials measured by weight parts: Acrylic resin prepolymer: 48 parts; Modified silicon nitride filler: 2.5 parts; Leveling agent BYK-310: 0.6 part; Photoinitiator benzoin dimethyl ether: 0.4 part; The preparation method of the metal component coating comprises the following steps: Step 1: Weigh each component of the raw materials according to the weight parts and prepare the materials. Step 2: Add the acrylic resin prepolymer, modified silicon nitride filler, leveling agent BYK-310, and photoinitiator benzoin dimethyl ether into a stirring kettle, start stirring, set the rotation speed to 300 r / min, stir mechanically for 40 min, let stand for 2 h, and then discharge the material, and that's it.

[0026] Example 3, a metal component coating based on polymer materials, comprising the following raw materials measured by weight parts: Acrylic resin prepolymer: 52 parts; Modified silicon nitride filler: 3 parts; Leveling agent BYK-315N: 1 part; Photoinitiator benzoin dimethyl ether: 0.5 part; The preparation method of the metal component coating comprises the following steps: Step 1: Weigh each component of the raw materials according to the weight parts and prepare the materials. Step 2: Add the acrylic resin prepolymer, modified silicon nitride filler, leveling agent BYK-315N, and photoinitiator benzoin dimethyl ether into a stirring kettle, start stirring, set the rotation speed to 400 r / min, stir mechanically for 30 min, let stand for 2 h, and then discharge the material, and that's it.

[0027] Comparative Example 1, a metal component coating based on polymer materials, comprising the following raw materials measured by weight parts: Acrylic resin prepolymer: 48 parts; Nanometer silicon nitride: 2.5 parts; Leveling agent BYK-310: 0.6 part; Photoinitiator benzoin dimethyl ether: 0.4 part; The preparation method of the metal component coating comprises the following steps: Step 1: Weigh each component raw material according to the weight parts and prepare the materials. Step 2: Add the acrylic resin prepolymer, nano-silicon nitride, leveling agent BYK-310, and photoinitiator benzoin dimethyl ether into a stirring kettle, start stirring, set the rotation speed to 300 r / min, stir mechanically for 40 min, then let it stand for 2 h, and discharge the material to obtain the product.

[0028] Comparative Example 2: A metal component coating based on polymer materials, comprising the following raw materials measured by weight parts: 48 parts of acrylic resin prepolymer; 2.5 parts of block polymer; 0.6 part of leveling agent BYK-310; 0.4 part of photoinitiator benzoin dimethyl ether; The preparation method of the metal component coating comprises the following steps: Step 1: Weigh each component raw material according to the weight parts and prepare the materials. Step 2: Add the acrylic resin prepolymer, block polymer, leveling agent BYK-310, and photoinitiator benzoin dimethyl ether into a stirring kettle, start stirring, set the rotation speed to 300 r / min, stir mechanically for 40 min, then let it stand for 2 h, and discharge the material to obtain the product.

[0029] Comparative Example 3: A metal component coating based on polymer materials, comprising the following raw materials measured by weight parts: 48 parts of acrylic resin prepolymer; 0.6 part of leveling agent BYK-310; 0.4 part of photoinitiator benzoin dimethyl ether; The preparation method of the metal component coating comprises the following steps: Step 1: Weigh each component raw material according to the weight parts and prepare the materials. Step 2: Add the acrylic resin prepolymer, leveling agent BYK-310, and photoinitiator benzoin dimethyl ether into a stirring kettle, start stirring, set the rotation speed to 300 r / min, stir mechanically for 40 min, then let it stand for 2 h, and discharge the material to obtain the product.

[0030] The acrylic resin prepolymer in the above examples and comparative examples is prepared by the following method: 3.5 g of butyl acrylate, 5 g of methyl methacrylate, and 1.2 g of isobornyl acrylate were added to ethyl acetate, stirred evenly, protected by introducing nitrogen, then the temperature was raised to 65 °C, and stirred for 30 min while maintaining the temperature to form a uniform reaction solution. Then 0.01 g of azobisisobutyronitrile was added to the reaction solution. After addition, the temperature was further raised to 85 °C, and the polymerization was continued while maintaining the temperature for 4 h. Then, the temperature was lowered and the product was discharged to obtain a prepolymer of acrylic resin.

[0031] The modified silicon nitride fillers in the above examples and comparative examples were prepared by the following method: Step S1: 1.5 g of dry nano-silicon nitride was ultrasonically dispersed in an ethanol solution, and then 0.5 g of 3-glycidoxypropyltriethoxysilane was added to the formed dispersion. After addition, the temperature was raised to 75 °C, and the reflux reaction was carried out for 4 h. Then, the solid product was centrifuged out, washed, and dried under vacuum to obtain a silicon nitride modifier. Step S2: 1.2 g of the silicon nitride modifier was added to an N,N-dimethylformamide medium, ultrasonically dispersed for 30 min to form a uniform dispersion, and then 1.8 g of a block copolymer and 0.1 g of tetrabutylammonium bromide were added to the dispersion. After addition, it was stirred evenly, and kept at 85 °C for 8 h. Then, the heating was stopped, the temperature was lowered, and the product was discharged to obtain the modified silicon nitride filler.

[0032] The preparation method of the block copolymer is as follows: 0.2 g of 5,5'-diallyl-[1,1'-biphenyl]-2,2'-diol was added to dimethyl sulfoxide. After addition, it was stirred and mixed evenly to form a uniform reaction solution, protected by introducing nitrogen. Then 0.05 g of allyl succinic anhydride was added to the reaction solution. After addition, it was stirred at room temperature for 3 h. Then 0.01 g of p-toluenesulfonic acid was added to the reaction solution, and the temperature was raised to 130 °C, and the polymerization was continued while maintaining the temperature for 18 h to obtain the block copolymer.

[0033] Figure shows the infrared analysis test chart of the block copolymer. The characteristic absorption peak at 3314 cm-1 is the characteristic absorption peak of the terminal hydroxyl group, the characteristic absorption peak at 3055 cm-1 is the carbon-hydrogen absorption peak of the benzene ring skeleton, the carbon-hydrogen absorption peak of the unsaturated carbon-carbon double bond is at 3023 cm-1, and the characteristic absorption peak of the carbon-oxygen double bond of the ester group is at 1708 cm-1.

[0034] Test example: The coatings in the examples and comparative examples were evenly coated on the surface of tinplate, irradiated with a mercury lamp of 500 mJ / cm2, and after complete curing to form a coating film, various performance tests were carried out. The test results are recorded in Table 1:

[0035] Note: Refer to the standard GB / T 1732-2020 to test the impact performance of the paint film; Refer to the national standard GB / T 11205-2009 to test the thermal conductivity of the coating film; Place the tinplate covered with the coating film in an oven at 120 °C, take it out after standing for 48 h, observe the phenomenon, and evaluate the high-temperature resistance of the coating.

[0036] According to the test results, it can be seen that the coating film prepared by adding modified silicon nitride filler significantly has stronger impact resistance, good thermal conductivity, and excellent high-temperature resistance.

[0037] The performance of the coating film prepared by directly adding nano boron nitride has significantly decreased. This may be due to the interfacial problem between nano boron nitride and the acrylic resin matrix, which cannot be evenly dispersed in the coating film. Therefore, it is difficult to efficiently exert its own strengthening advantages and construct a complete thermal conduction path.

[0038] After replacing the modified silicon nitride filler with a block polymer, the advantages of nano silicon nitride cannot be utilized, so the mechanical properties have significantly decreased. However, due to the large number of unsaturated alkenyl groups in the structure of the block polymer, it can form crosslinks with the acrylic resin prepolymer, which has a positive effect on the mechanical strength of the coating film.

[0039] In this article, specific examples are used to elaborate on the principles and implementation methods of the present invention. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present invention, including the best mode, and also enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The protection scope of this invention patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to the literal description of the claims, or if they include equivalent structural elements that have no substantial difference from the literal description of the claims, then these other embodiments should also be included within the scope of the claims.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a metal component coating based on a polymer material, characterized in that: The metal component coating comprises the following raw materials measured in parts by weight: 46-52 parts of acrylic resin prepolymer; 1-3 parts of modified silicon nitride filler; 0.5-1 part of leveling agent; Photoinitiator 0.3-0.5 parts; The preparation method comprises the following steps: The first step is to weigh the raw materials of each component according to the weight portion and prepare the materials; The second step is to add acrylic resin prepolymer, modified silicon nitride filler, leveling agent and photoinitiator into the stirring kettle, start stirring, set the speed to 200-400r / min, mechanically stir for 30-60min, let it stand for 1-2h, and then discharge.

2. The method for preparing a metal component coating based on a polymer material according to claim 1, characterized in that: The preparation method of the acrylic resin prepolymer is as follows: Butyl acrylate, methyl methacrylate and isobornyl acrylate are added to ethyl acetate, stirred evenly, and nitrogen is introduced for protection. Then the temperature is increased to 60-70°C, and the mixture is stirred for 20-30 minutes to form a uniform reaction liquid. Azobisisobutyronitrile is then added to the reaction liquid. After the addition is completed, the temperature is further increased to 80-90°C, and the polymerization is continued for 3-6 hours. Then the temperature is reduced and the material is discharged to obtain an acrylic resin prepolymer.

3. The method for preparing a metal component coating based on a polymer material according to claim 2, characterized in that: The mass ratio of butyl acrylate, methyl methacrylate, isobornyl acrylate and azobisisobutyronitrile is 30-40:50-55:10-15:0.1-0.

2.

4. The method for preparing a metal component coating based on a polymer material according to claim 1, characterized in that: The specific preparation method of the modified silicon nitride filler comprises the following steps: Step S1, using a silane coupling agent to perform surface modification on nano silicon nitride to obtain a modified silicon nitride; Step S2: In N,N-dimethylformamide medium, the silicon nitride modified body is further modified using a block polymer to obtain a modified silicon nitride filler.

5. The method for preparing a metal component coating based on a polymer material according to claim 4, characterized in that: In step S1, the silane coupling agent is 3-glycidyloxypropyltrimethoxysilane or 3-glycidyloxypropyltriethoxysilane.

6. The method for preparing a metal component coating based on a polymer material according to claim 4, characterized in that: In step S2, the preparation method of the block polymer is as follows: Add 5,5'-diallyl-[1,1'-biphenyl]-2,2'-diol to dimethyl sulfoxide, stir and mix evenly to form a uniform reaction solution, introduce nitrogen protection, then add allyl succinic anhydride to the reaction solution, stir at room temperature for 2-4 hours, then add a phase transfer catalyst to the reaction solution, raise the temperature to 120-130°C, and keep the temperature for polymerization for 16-24 hours to obtain a block polymer.

7. The method for preparing a metal component coating based on a polymer material according to claim 6, characterized in that: The molar ratio of the 5,5'-diallyl-[1,1'-biphenyl]-2,2'-diol to allyl succinic anhydride is 1:0.4-0.

5.

8. The method for preparing a metal component coating based on a polymer material according to claim 6, characterized in that: The phase transfer catalyst is p-toluenesulfonic acid.

9. The method for preparing a metal component coating based on a polymer material according to claim 1, characterized in that: The defoamer is any one of BYK-333, BYK-310 or BYK-315N; the initiator is benzoin dimethyl ether.

10. A metal component coating based on polymer materials, characterized in that: The method is prepared according to any one of claims 1 to 9.

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