Functional polymer coating for metal element and preparation method of functional polymer coating

Abstract

The invention belongs to the technical field of coatings, and particularly relates to a functional polymer coating for metal elements and a preparation method thereof.The coating comprises a component A and a component B. The component A comprises, by weight, 100 parts of bisphenol A epoxy resin, 15-30 parts of polyacrylate, 1-2 parts of a flatting agent, 1-2.5 parts of a dispersing agent and 0.5-2 parts of a defoaming agent; 0.8-1.2 parts of a modified graphene oxide filler; 7-11 parts of an inorganic pigment; and the component B comprises 15-20 parts of a curing agent. The solvent-free epoxy resin coating is adopted, solvent volatilization does not exist in the curing process, a paint film is compact, the situation that micropores are generated due to solvent volatilization when an existing organic coating is cured is avoided, the medium corrosion resistance of the coating is improved, one-time film forming is thick, the construction frequency is reduced, and the cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and particularly relates to a functional polymer coating for metal components and a preparation method thereof. Background Art

[0002] With the rapid development of electronic information technology, the operating speed requirements for electronic devices are getting faster and faster, the power of electronic devices is getting larger and larger, and the volume is getting smaller and smaller. Therefore, the temperature rise caused by high power consumption of electronic devices increases sharply, and the increase in temperature poses a great challenge to the reliability of electronic devices. Coatings for metal components or metal electronic components need to have good heat dissipation performance. In the prior art, graphene coatings are often applied to metal components to exert excellent heat conduction and heat dissipation functions. However, during the process of curing and film formation of organic coatings, micropores will be left, and corrosion factors will invade the metal matrix through the micropores. Graphene can be used as a filler to block the micropores and play an excellent corrosion protection role. However, due to the strong interaction between graphene sheets, directly adding graphene to the resin, graphene is extremely prone to agglomeration, resulting in pitting and bubbling on the coating surface, and even generating more micropores, severely affecting the corrosion resistance, and further affecting the quality and service durability of metal components. Summary of the Invention

[0003] The purpose of the present invention is to provide a functional polymer coating for metal components and a preparation method thereof.

[0004] The purpose of the present invention can be achieved by the following technical solutions: A functional polymer coating for metal components, comprising component A and component B. Component A comprises the following raw materials in parts by weight: 100 parts of bisphenol A epoxy resin, 15 - 30 parts of polyacrylate, 1 - 2 parts of leveling agent, 1 - 2.5 parts of dispersant, 0.5 - 2 parts of defoamer, 0.8 - 1.2 parts of modified graphene oxide filler, and 7 - 11 parts of inorganic pigment; Component B is 15 - 20 parts of curing agent.

[0005] Further, the preparation of the modified graphene oxide filler comprises the following steps: The first step: Add graphite oxide and 100 - 150 ml of solvent DMF into a reaction flask, then dropwise add thionyl chloride drop by drop while stirring, heat the reaction flask to 70 - 75 °C, keep warm and stir slowly for 1 - 2 days. After the reaction is completed, filter, wash with anhydrous acetonitrile, and dry to obtain acyl chloride graphite oxide; Step 2: Add the graphitic oxide chloride prepared in the first step and 300 - 500 ml of anhydrous acetonitrile into the reaction flask. Then add 3 - octyl - 1H - pyrrole. While stirring, heat the reaction flask to 60 - 65 °C and keep the temperature for 2 - 3 days. After the reaction is completed, filter, wash with acetone to remove the unreacted raw materials, and dry to obtain the modified graphitic oxide filler.

[0006] Reaction mechanism of the modified graphitic oxide filler: Graphitic oxide contains a large number of oxygen - containing groups such as hydroxyl, carboxyl, epoxy, and carbonyl groups. Some of the carboxyl groups can react with thionyl chloride to obtain graphitic oxide chloride. The graphitic oxide chloride can undergo a nucleophilic substitution reaction with 3 - octyl - 1H - pyrrole in an acetonitrile system to obtain the modified graphitic oxide filler.

[0007] Furthermore, the addition amount of the graphitic oxide is 1.2 - 1.5 g.

[0008] Furthermore, the addition amount of the thionyl chloride is 4.2 - 5.5 g.

[0009] Furthermore, the addition amount of the 3 - octyl - 1H - pyrrole is 0.8 - 1.0 g.

[0010] Furthermore, the inorganic pigment is titanium dioxide or black iron oxide.

[0011] Furthermore, the curing agent is one of aromatic amines, aliphatic amines or polyamides.

[0012] A preparation method of a functional polymer coating for metal components specifically includes the following steps: Step 1: Preparation of Component A S1. Add the formulated amount of epoxy resin and polyacrylate into a blender and mix evenly; S2. While stirring, add a leveling agent, a dispersant and an antifoaming agent to the mixture in step S1; S3. While stirring, add the modified graphitic oxide filler to the mixture in step S2, stir for 20 - 30 min, then add the inorganic pigment and continue stirring for 20 - 30 min to obtain Component A; Step 2: Preparation of the coating While stirring, add Component B to Component A. After adding, continue stirring for 1 - 2 h, then filter to obtain the functional polymer coating for metal components.

[0013] Advantages of the present invention: This application uses a solvent-free epoxy resin coating. During the curing process, there is no solvent volatilization, and the paint film is dense, avoiding the formation of micropores due to solvent volatilization during the curing of existing organic coatings, improving the corrosion resistance of the coating to media. The film thickness formed in one coat is relatively thick, thereby reducing the number of construction times and lowering the cost. The added modified graphene oxide filler is grafted with hydrophobic 3-octyl-1H-pyrrole, which reduces the hydrophilicity and enhances the hydrophobicity of graphene oxide. When added to the coating, the modified graphene oxide filler has good dispersibility in the coating, the contact angle of the coating increases, and thus the hydrophobic performance of the coating is enhanced, which can better prevent the diffusion of corrosive media.

[0014] 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

[0015] 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.

[0016] Figure 1 In [the figure], A is the infrared spectrum of graphene oxide; B is the infrared spectrum of the modified graphene oxide filler; Figure 2 In [the figure], a is the enlarged cross-sectional view of the coating in Comparative Example 1; b is the enlarged cross-sectional view of the coating in Example 1. In Figure a, due to the poor dispersibility of graphene oxide, when the epoxy resin cures, the heat dissipation is uneven, resulting in many small bubbles on the coating surface. The small bubbles in the coating of Example 1 are reduced a lot because the added modified graphene oxide filler has good dispersibility, and thus the heat dissipation performance is better, thereby reducing the generation of small bubbles. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with 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 of 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.

[0018] The preparation of the modified graphene oxide filler described in the following embodiments includes the following steps: Step 1: Add 1.2 - 1.5 g of graphite oxide and 100 - 150 ml of the solvent DMF into a reaction flask. Then, while stirring, gradually dropwise add 4.2 - 5.5 g of thionyl chloride. Heat the reaction flask to 70 - 75 °C and keep it warm with slow stirring for 1 - 2 days. After the reaction is completed, filter, wash with anhydrous acetonitrile, and dry to obtain acid chlorinated graphite oxide. Step 2: Add the acid chlorinated graphite oxide prepared in the first step and 300 - 500 ml of anhydrous acetonitrile into a reaction flask. Then add 0.8 - 1.0 g of 3 - octyl - 1H - pyrrole. While stirring, heat the reaction flask to 60 - 65 °C and keep it warm for reaction for 2 - 3 days. After the reaction is completed, filter, wash with acetone to remove unreacted raw materials, and dry to obtain modified graphene oxide filler. As Figure 1 shown, A is the infrared spectrum of graphite oxide. The peak at 3425 cm - 1 is the hydroxyl group in graphite oxide or the absorbed water peak, and the peak at 1638 cm - 1 is the stretching vibration peak of the carbonyl group. B is the infrared spectrum of the modified graphene oxide filler. The peaks at 2845 cm - 1 and 2913 cm - 1 are the C - H stretching vibration peaks of the long - chain main chain. The stretching vibration peak of the carbonyl group at 1638 cm - 1 is significantly weakened because some carboxyl groups on the graphite oxide participated in the reaction. The peak at 1489 cm - 1 is the C - N stretching vibration peak, indicating that 3 - octyl - 1H - pyrrole was successfully grafted onto the graphite oxide.

[0019] Example 1, a functional polymer coating for metal components, includes component A and component B. Component A includes the following raw materials in parts by weight: 100 parts of bisphenol A epoxy resin, 15 parts of polyacrylate, 1.5 parts of leveling agent, 1.5 parts of dispersant, 1 part of defoaming agent, 0.8 part of modified graphene oxide filler, and 10 parts of inorganic pigment. The inorganic pigment is titanium dioxide. Component B is 17 parts of curing agent. The curing agent is aromatic amine. A preparation method of a functional polymer coating for metal components specifically includes the following steps: Step 1: Preparation of component A S1, Add the formulated amount of epoxy resin and polyacrylate into a mixer and mix evenly. S2, While stirring, add the leveling agent, dispersant, and defoaming agent to the mixture in step S1. S3, While stirring, add the modified graphene oxide filler to the mixture in step S2, stir for 30 min, then add the inorganic pigment, and continue stirring for 30 min to obtain component A. Step 2: Preparation of the coating While stirring, add Component B to Component A. After the addition is complete, continue stirring for 1.5 h, and then filter to obtain the functional polymer coating for metal components.

[0020] Example 2: A functional polymer coating for metal components, comprising Component A and Component B. Component A comprises the following raw materials in parts by weight: 100 parts of bisphenol A epoxy resin, 20 parts of polyacrylate, 2 parts of leveling agent, 2 parts of dispersant, 0.5 part of defoaming agent, 1.0 part of modified graphene oxide filler, and 7 parts of inorganic pigment; The inorganic pigment is black iron oxide; Component B is 16 parts of curing agent; The curing agent is aliphatic amine; A preparation method of a functional polymer coating for metal components specifically comprises the following steps: Step 1: Preparation of Component A S1, Add the formulated amounts of epoxy resin and polyacrylate to a blender and mix evenly; S2, While stirring, add the leveling agent, dispersant, and defoaming agent to the mixture in Step S1; S3, While stirring, add the modified graphene oxide filler to the mixture in Step S2, stir for 25 min, then add the inorganic pigment, and continue stirring for 20 min to obtain Component A; Step 2: Preparation of the coating While stirring, add Component B to Component A. After the addition is complete, continue stirring for 2 h, and then filter to obtain the functional polymer coating for metal components.

[0021] Example 3: A functional polymer coating for metal components, comprising Component A and Component B. Component A comprises the following raw materials in parts by weight: 100 parts of bisphenol A epoxy resin, 30 parts of polyacrylate, 1.5 parts of leveling agent, 1.5 parts of dispersant, 2 parts of defoaming agent, 1.2 parts of modified graphene oxide filler, and 11 parts of inorganic pigment; The inorganic pigment is titanium dioxide; Component B is 20 parts of curing agent; The curing agent is polyamide; A preparation method of a functional polymer coating for metal components specifically comprises the following steps: Step 1: Preparation of Component A S1, Add the formulated amounts of epoxy resin and polyacrylate to a blender and mix evenly; S2, While stirring, add the leveling agent, dispersant, and defoaming agent to the mixture in Step S1; S3. While stirring, add the modified graphene oxide filler to the mixture in step S2, stir for 30 min, then add the inorganic pigment, and continue stirring for 30 min to obtain Component A; Step 2: Preparation of the coating While stirring, add Component B to Component A. After the addition is complete, continue stirring for 2 h, and then filter to obtain the functional polymer coating for metal components.

[0022] Comparative Example 1. A functional polymer coating for metal components, including Component A and Component B. The Component A includes the following raw materials in parts by weight: 100 parts of bisphenol A epoxy resin, 15 parts of polyacrylate, 1.5 parts of leveling agent, 1.5 parts of dispersant, 1 part of defoamer, 0.8 part of graphite oxide, and 10 parts of inorganic pigment; The inorganic pigment is titanium dioxide; The Component B is 17 parts of curing agent; The curing agent is aromatic amine; A preparation method of a functional polymer coating for metal components specifically includes the following steps: Step 1: Preparation of Component A S1. Add the formulated amount of epoxy resin and polyacrylate to a blender and mix evenly; S2. While stirring, add the leveling agent, dispersant, and defoamer to the mixture in step S1; S3. While stirring, add the modified graphene oxide filler to the mixture in step S2, stir for 30 min, then add the inorganic pigment, and continue stirring for 30 min to obtain Component A; Step 2: Preparation of the coating While stirring, add Component B to Component A. After the addition is complete, continue stirring for 1.5 h, and then filter to obtain the functional polymer coating for metal components.

[0023] Perform performance tests on the coatings obtained in the above examples and Comparative Example 1: (1) Coat the coatings prepared in each example on the surface of aluminum metal, and test the coatings; use the goniometry method of a JC200DS contact angle measuring instrument to measure the coatings, and the results are shown in Table 1: Table 1

[0024] (2) According to GB / T 1771-2007 "Paints and varnishes - Determination of resistance to neutral salt spray", conduct a salt spray test on the salt spray resistance of the coatings, and the results are shown in Table 2: Table 2

[0025] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the concept of the invention or exceed the scope defined by this claims, they should fall within the protection scope of the present invention.

Claims

1. A functional polymer coating for metal components, characterized in that: The invention comprises a component A and a component B, wherein the component A comprises the following raw materials in parts by weight: 100 parts of bisphenol A epoxy resin, 15-30 parts of polyacrylate, 1-2 parts of leveling agent, 1-2.5 parts of dispersant, 0.5-2 parts of defoamer, 0.8-1.2 parts of modified graphene oxide filler, and 7-11 parts of inorganic pigment; The component B is 15-20 parts of curing agent.

2. The functional polymer coating for metal components according to claim 1, characterized in that: The preparation of the modified graphene oxide filler comprises the following steps: Step 1: Add graphite oxide and 100-150 ml of DMF solvent into a reaction bottle, then add thionyl chloride dropwise while stirring, heat the reaction bottle to 70-75°C, keep warm and slowly stir for 1-2 days, filter after the reaction, wash with anhydrous acetonitrile, and dry to obtain chlorinated graphite oxide; Step 2: Add the acylated graphite oxide prepared in the first step and 300-500 ml of anhydrous acetonitrile into the reaction bottle, then add 3-octyl-1H-pyrrole, heat the reaction bottle to 60-65°C while stirring, and keep the reaction for 2-3 days. After the reaction is completed, filter, wash with acetone to remove unreacted raw materials, and dry to obtain modified graphene oxide filler.

3. The functional polymer coating for metal components according to claim 2, characterized in that: The added amount of the graphite oxide is 1.2-1.5g.

4. The functional polymer coating for metal components according to claim 2, characterized in that: The added amount of the thionyl chloride is 4.2-5.5g.

5. The functional polymer coating for metal components according to claim 2, characterized in that: The added amount of the 3-octyl-1H-pyrrole is 0.8-1.0 g.

6. The functional polymer coating for metal components according to claim 1, characterized in that: The inorganic pigment is titanium dioxide or black iron oxide.

7. The functional polymer coating for metal components according to claim 1, characterized in that: The curing agent is one of aromatic amine, aliphatic amine or polyamide.

8. A method for preparing a functional polymer coating for metal components as claimed in claim 1, characterized in that: The specific steps include: Step 1: Preparation of component A S1, adding the formulated amount of epoxy resin and polyacrylate into a blender and mixing them evenly; S2, adding a leveling agent, a dispersant and a defoaming agent to the mixed solution of step S1 while stirring; S2, adding the modified graphene oxide filler to the mixed solution of step S2 while stirring, stirring for 20-30 minutes, then adding the inorganic pigment, and continuing to stir for 20-30 minutes to obtain component A; Step 2: Preparation of coating Add component B to component A while stirring. Continue stirring for 1-2 hours after the addition is complete. Filter to obtain a functional polymer coating for metal components.

Images