Preparation method of tertiary amine-containing acrylic resin and application of tertiary amine-containing acrylic resin in epoxy curing agent

Abstract

The invention relates to the technical field of epoxy coatings, and particularly discloses a preparation method of tertiary amine-containing acrylic resin and application of the tertiary amine-containing acrylic resin in an epoxy curing agent. The preparation method of the tertiary amine-containing acrylic resin comprises the following specific steps: dissolving a tertiary amine-containing acrylic monomer and an acrylate monomer in a solvent, heating under the protection of nitrogen, adding an initiator and a chain transfer agent, and reacting to obtain the tertiary amine-containing acrylic resin; the tertiary amine-containing acrylic resin comprises the following raw materials in parts by weight: 20-50 parts of a tertiary amine-containing acrylic monomer, 50-80 parts of an acrylate monomer, 0.5-2 parts of an initiator, 0.1-1 part of a chain transfer agent and 90-110 parts of a solvent, through the synergistic effect of all the components, the prepared tertiary amine-containing acrylic resin can be uniformly cured with epoxy resin, the epoxy curing speed is adjusted by utilizing the steric hindrance effect of tertiary amine groups, the adhesive force of the epoxy resin and a base material is enhanced, and the hardness and corrosion resistance of the cured epoxy resin are improved.

Description

Technical Field

[0001] This application relates to the field of epoxy coating technology, and in particular to a method for preparing a tertiary amine-containing acrylic resin and its application in epoxy curing agents. Background Technology

[0002] In the field of chemical materials, epoxy resins are widely used in numerous industries due to their excellent physical properties and chemical stability. They possess good adhesion, corrosion resistance, and insulation properties, making them extensively used in coatings, adhesives, electronic packaging, and composite materials. With continuous industrial development, the requirements for epoxy resin performance are also increasing, especially in terms of curing. Suitable curing agents can significantly improve the performance of epoxy resins, thereby expanding their application range.

[0003] To achieve the curing of epoxy resins, the industry commonly employs various curing agents and curing methods. Commonly used curing agents include amines and acid anhydrides. However, acid anhydride curing agents suffer from long curing times and require the addition of accelerators. Currently, amine curing agents are predominantly available on the market. However, traditional amine curing agents are solid at room temperature and require heating to dissolve before use, which is inconvenient. Furthermore, the small-molecule amines used in amine curing agents are volatile and easily separate from the epoxy resin, leading to uneven curing. Summary of the Invention

[0004] To address the shortcomings of existing epoxy curing agents, this application provides a method for preparing a tertiary amine-containing acrylic resin and its application in epoxy curing agents.

[0005] In a first aspect, this application provides a method for preparing a tertiary amine-containing acrylic resin, which adopts the following technical solution: A method for preparing a tertiary amine-containing acrylic resin includes the following specific steps: dissolving a tertiary amine-containing acrylic monomer and an acrylate monomer in a solvent, heating under the protection of nitrogen, and then adding an initiator and a chain transfer agent to react and obtain a tertiary amine-containing acrylic resin; The tertiary amine-containing acrylic resin comprises the following raw materials in parts by weight: 20-50 parts of tertiary amine-containing acrylic monomer, 50-80 parts of acrylate monomer, 0.5-2 parts of initiator, 0.1-1 parts of chain transfer agent, and 90-110 parts of solvent.

[0006] By employing the above technical solution, a polymerized acrylic resin containing tertiary amines is used to fix the tertiary amine groups, reducing volatility. The catalytic sites are chemically fixed on the prepared resin backbone through the polymerization of the tertiary amine groups with the acrylate double bonds. The steric hindrance effect of the tertiary amine groups is utilized to regulate the epoxy curing speed. The prepared tertiary amine-containing acrylic resin enhances its compatibility with epoxy resin through its own polar groups, achieving uniform curing and reducing the problem of phase separation common in traditional amines. Simultaneously, the tertiary amine-containing acrylic resin also enhances the adhesion between the epoxy resin and the substrate, improving the hardness and corrosion resistance of the cured epoxy resin.

[0007] Preferably, the heating temperature is 80-130℃.

[0008] Preferably, the acrylate monomer is at least one selected from butyl methacrylate, butyl acrylate, ethyl acrylate, ethyl methacrylate, and isooctyl acrylate.

[0009] By employing the above technical solution, butyl methacrylate, butyl acrylate, ethyl acrylate, ethyl methacrylate, and isooctyl acrylate are used as monomers for tertiary amine-containing acrylic resins. The long-chain alkyl ester groups provide molecular chain flexibility, enhancing the toughness of the cured epoxy resin and promoting strong adhesion to non-polar substrates. Simultaneously, butyl methacrylate, butyl acrylate, ethyl acrylate, ethyl methacrylate, and isooctyl acrylate are acrylic monomers with moderate reactivity, effectively controlling the polymerization rate of the acrylate monomers and the tertiary amine monomers. This addresses the problem of short pot life in epoxy curing agents caused by high reactivity, balancing the curing rate and pot life of the epoxy resin.

[0010] Preferably, the chain transfer agent is at least one of dodecyl mercaptan and 2,4-diphenyl-4-methyl-1-pentene.

[0011] Preferably, the tertiary amine-containing acrylic monomer is at least one of dimethylaminoethyl methacrylate and diethylaminoethyl acrylate.

[0012] By adopting the above technical solutions, dimethylaminoethyl methacrylate and diethylaminoethyl acrylate can utilize the large-volume substituents around the tertiary amine group to delay the ring-opening efficiency of epoxy, regulate the curing rate of epoxy resin, and extend the pot life.

[0013] Preferably, the tertiary amine-containing acrylic monomer is surface-treated with titanium dioxide.

[0014] By employing the above technical solution, the tertiary amine acrylic monomer is surface-treated with titanium dioxide. Titanium dioxide absorbs ultraviolet light, protecting the cured epoxy resin from photodegradation and improving its anti-aging properties. Simultaneously, the titanium dioxide on the surface of the tertiary amine acrylic monomer can enhance the hardness and wear resistance of the cured epoxy resin.

[0015] Preferably, the tertiary amine acrylic monomer is surface-treated with titanium dioxide, which includes the following specific steps: ultrasonically dispersing titanium dioxide in water, adding the tertiary amine acrylic monomer to form a mixed solution, ultrasonically dispersing, performing radiation grafting under the protection of nitrogen, and heating and extracting the irradiated mixed solution to obtain the tertiary amine acrylic monomer surface-treated with titanium dioxide.

[0016] By employing the above technical solution, ultrasonic dispersion first exposes the hydroxyl groups on the surface of titanium dioxide, thereby improving the surface bonding effect between titanium dioxide and the tertiary amine-containing acrylic resin. Radiation then initiates the reaction between the double bonds of the tertiary amine-containing acrylic monomer and the hydroxyl groups on the titanium dioxide surface, forming stable covalent bonds, reducing phase separation, and improving the dispersibility of titanium dioxide.

[0017] Preferably, the heating temperature is 75-85℃.

[0018] Secondly, this application provides an application of tertiary amine-containing acrylic resin in epoxy curing agents, employing the following technical solution: An application of a tertiary amine-containing acrylic resin as an epoxy curing agent includes the following specific steps: mixing the tertiary amine-containing acrylic resin with an epoxy resin, coating it on the surface of a substrate, and then heating and curing it, thus completing the application of the tertiary amine-containing acrylic resin as an epoxy curing agent.

[0019] By adopting the above technical solution, the high catalytic activity of the tertiary amine acrylic resin and epoxy resin can be utilized to effectively catalyze the ring-opening of epoxy resin and extend the curing pot life of epoxy resin.

[0020] Preferably, the mass ratio of the tertiary amine-containing acrylic resin to the epoxy resin is 1:(3-5).

[0021] In summary, this application has the following beneficial effects: 1. This application utilizes a polymerized acrylic resin containing tertiary amines to reduce volatility. Through the polymerization of tertiary amine groups with acrylate double bonds, the curing rate of the epoxy resin is adjusted, extending its pot life. The prepared tertiary amine-containing acrylic resin enhances its compatibility with epoxy resin using its own polar groups, achieving uniform curing, reducing the problem of phase separation common in traditional amine resins, and improving the adhesion and hardness of the cured epoxy resin.

[0022] 2. In this application, dimethylaminoethyl methacrylate and diethylaminoethyl acrylate are used as tertiary amine-containing acrylic monomers. The tertiary amine-containing acrylic monomers are surface-treated with titanium dioxide, which can absorb ultraviolet light and protect the cured epoxy resin from photodegradation, thereby improving the anti-aging properties, hardness and wear resistance of the cured epoxy resin. Detailed Implementation

[0023] The present application will be further described in detail below with reference to the embodiments.

[0024] All raw materials used in the examples are commercially available. Example

[0025] Example 1 This embodiment provides a tertiary amine-containing acrylic resin comprising the following raw materials in parts by weight: 35 kg of tertiary amine-containing acrylic monomer, 65 kg of acrylate monomer, 1.2 kg of initiator, 0.5 kg of chain transfer agent, and 100 kg of solvent. The tertiary amine-containing acrylic monomer is dimethylaminoethyl methacrylate, the acrylate monomer is a mixture of butyl methacrylate and butyl acrylate in a mass ratio of 1:1, the solvent is propylene glycol methyl ether, the initiator is azobisisobutyronitrile, and the chain transfer agent is dodecyl mercaptan.

[0026] The preparation method of tertiary amine-containing acrylic resin includes the following specific steps: dissolving tertiary amine-containing acrylic monomer and acrylate monomer in a solvent, heating to 80°C under nitrogen protection, adding initiator and chain transfer agent and reacting for 8 hours to obtain tertiary amine-containing acrylic resin.

[0027] The application of tertiary amine-containing acrylic resin as an epoxy curing agent includes the following specific steps: mixing tertiary amine-containing acrylic resin with epoxy resin at a mass ratio of 1:3, using SM828 from Jiangsu Sanmu Group as the epoxy resin, coating the substrate surface, and then heating to 60℃ for 4 hours to cure, thus completing the application of tertiary amine-containing acrylic resin as an epoxy curing agent.

[0028] Example 2 The difference between Example 2 and Example 1 is that the preparation method of the tertiary amine acrylic resin includes the following specific steps: dissolving the tertiary amine acrylic monomer and acrylate monomer in a solvent, heating to 130°C under the protection of nitrogen, and then adding an initiator and chain transfer agent to react for 4 hours to obtain the tertiary amine acrylic resin.

[0029] Example 3 The difference between Example 3 and Example 1 is that the amount of tertiary amine acrylic monomer used in the tertiary amine acrylic resin raw material is 20 kg, the amount of acrylate monomer used is 80 kg, the amount of initiator used is 0.5 kg, the amount of chain transfer agent used is 1 kg, and the amount of solvent used is 90 kg.

[0030] Example 4 The difference between Example 4 and Example 1 is that the amount of tertiary amine acrylic monomer used in the tertiary amine acrylic resin raw material is 50 kg, the amount of acrylate monomer used is 50 kg, the amount of initiator used is 2 kg, the amount of chain transfer agent used is 0.1 kg, and the amount of solvent used is 110 kg.

[0031] Example 5 The difference between Example 5 and Example 1 is that the tertiary amine acrylic monomer is diethylaminoethyl acrylate.

[0032] Example 6 The difference between Example 6 and Example 1 is that the application of tertiary amine acrylic resin as an epoxy curing agent includes the following specific steps: mixing tertiary amine acrylic resin and epoxy resin in a mass ratio of 1:5, using SM828 from Jiangsu Sanmu Group as the epoxy resin, coating the substrate surface, and then heating to 60°C for 4 hours to cure, thus completing the application of tertiary amine acrylic resin as an epoxy curing agent.

[0033] Example 7 The difference between Example 7 and Example 1 is that the tertiary amine acrylic monomer is surface-treated with titanium dioxide.

[0034] The preparation method of acrylic resin containing tertiary amine includes the following specific steps: S1: Titanium dioxide was ultrasonically dispersed in water, and a tertiary amine acrylic acid monomer was added to form a mixed solution. The mass ratio of titanium dioxide, water, and tertiary amine acrylic acid monomer was 1:50:5. The mixture was ultrasonically dispersed and then irradiated under nitrogen protection. The irradiated mixed solution was heated to 80°C and extracted for 48 hours to obtain a tertiary amine acrylic acid monomer with titanium dioxide surface treatment.

[0035] S2: The tertiary amine-containing acrylic monomer and acrylate monomer grafted with titanium dioxide on the surface are dissolved in a solvent. Under the protection of nitrogen, the mixture is heated to 80°C, and then an initiator and chain transfer agent are added and reacted for 8 hours to obtain the tertiary amine-containing acrylic resin.

[0036] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that an equal amount of aminoethyl methacrylate was used instead of the tertiary amine acrylic resin raw material.

[0037] Performance testing Based on the tertiary amine-containing acrylic resins and their applications in epoxy curing agents provided in Examples 1-7 and Comparative Example 1 of this application, the following performance tests were conducted, and the specific test results are shown in Table 1.

[0038] Detection methods I. Adhesion Test After curing the tertiary amine-containing acrylic resin and epoxy resin prepared in this application, the adhesion effect of the epoxy resin after curing was tested in accordance with the standard of "Cross-cut test of paint and varnish film".

[0039] II. Hardness After curing the tertiary amine-containing acrylic resin and epoxy resin prepared in this application, the hardness of the epoxy resin after curing was tested in accordance with the standard GB / T6739-2006 "Determination of Hardness of Paint and Varnish Film by Pencil Method".

[0040] III. Salt Spray Resistance After curing the tertiary amine-containing acrylic resin and epoxy resin prepared in this application, the salt spray resistance of the epoxy resin after curing was tested in accordance with the standard GB / T10125-2012 "Artificial Atmosphere Corrosion Test - Salt Spray Test".

[0041] IV. Aging Test After curing the tertiary amine-containing acrylic resin and epoxy resin prepared in this application, the samples were placed in a UV aging chamber for UV aging treatment. After a period of treatment, the color difference was measured using a colorimeter. The aging conditions were set as follows: irradiation intensity 0.8 W / m², aging temperature 60 °C, and aging time 30 days. The color difference values ​​of the samples before and after aging were measured.

[0042] Table 1: Performance Test Results Data Table The performance test results show that the tertiary amine-containing acrylic resin prepared in this application can be uniformly cured with epoxy resin, exhibiting good compatibility. Furthermore, it maintains a moderate curing speed during the curing process, promoting strong adhesion between the epoxy resin and the substrate. By immobilizing the tertiary amine groups in the polymerized acrylic resin, volatility is reduced, mitigating the problems of easy volatility and phase separation associated with traditional small-molecule amines. A comparison between Comparative Example 1 and Example 1 reveals that Comparative Example 1 uses aminoethyl methacrylate, a primary amine acrylic monomer. Performance test results show that, compared to tertiary amine acrylic resin, primary amine acrylic resin exhibits yellowing during aging tests when used as an epoxy curing agent, thus affecting the adhesion between the epoxy resin and the substrate. This further demonstrates that the use of tertiary amine-containing acrylic resin in this application enhances the adhesion between the epoxy resin and the substrate, and improves the hardness and corrosion resistance of the cured epoxy resin.

[0043] As demonstrated in Example 7, surface treatment of the tertiary amine acrylic monomer with titanium dioxide, as shown in the performance test results, enables the titanium dioxide to absorb ultraviolet light, protecting the cured epoxy resin from photodegradation and improving its anti-aging properties. Furthermore, the bonding between the tertiary amine acrylic monomer and titanium dioxide on the surface can enhance the hardness and wear resistance of the cured epoxy resin.

[0044] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing an acrylic resin containing tertiary amine, characterized in that, The specific steps include: dissolving tertiary amine-containing acrylic monomers and acrylate monomers in a solvent, heating under nitrogen protection, and then adding an initiator and chain transfer agent to react and obtain tertiary amine-containing acrylic resin; The tertiary amine-containing acrylic resin comprises the following raw materials in parts by weight: 20-50 parts of tertiary amine-containing acrylic monomer, 50-80 parts of acrylate monomer, 0.5-2 parts of initiator, 0.1-1 parts of chain transfer agent, and 90-110 parts of solvent.

2. The method for preparing the tertiary amine-containing acrylic resin according to claim 1, characterized in that, The heating temperature is 80-130℃.

3. The method for preparing the tertiary amine-containing acrylic resin according to claim 1, characterized in that, The acrylate monomer is at least one of butyl methacrylate, butyl acrylate, ethyl acrylate, ethyl methacrylate, and isooctyl acrylate.

4. The method for preparing the tertiary amine-containing acrylic resin according to claim 1, characterized in that, The chain transfer agent is at least one of dodecanethiol and 2,4-diphenyl-4-methyl-1-pentene.

5. The method for preparing the tertiary amine-containing acrylic resin according to claim 1, characterized in that, The tertiary amine-containing acrylic monomer is at least one of dimethylaminoethyl methacrylate and diethylaminoethyl acrylate.

6. The method for preparing the tertiary amine-containing acrylic resin according to claim 5, characterized in that, The tertiary amine-containing acrylic monomer is surface-treated with titanium dioxide.

7. The method for preparing the tertiary amine-containing acrylic resin according to claim 6, characterized in that, The tertiary amine acrylic monomer is surface-treated with titanium dioxide, including the following specific steps: titanium dioxide is ultrasonically dispersed in water, the tertiary amine acrylic monomer is added to form a mixed solution, ultrasonically dispersed, and then irradiated under the protection of nitrogen. The irradiated mixed solution is heated and extracted to obtain the tertiary amine acrylic monomer surface-treated with titanium dioxide.

8. The method for preparing the tertiary amine-containing acrylic resin according to claim 7, characterized in that, The heating temperature is 75-85℃.

9. The application of the tertiary amine-containing acrylic resin as described in any one of claims 1-8 in an epoxy curing agent, characterized in that, The specific steps include: mixing tertiary amine-containing acrylic resin with epoxy resin, coating the substrate surface, and then heating and curing to complete the application of tertiary amine-containing acrylic resin as an epoxy curing agent.

10. The application of the tertiary amine-containing acrylic resin according to claim 9 in epoxy curing agents, characterized in that, The mass ratio of the tertiary amine-containing acrylic resin to the epoxy resin is 1:(3-5).

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