Phenolic amide epoxy curing agent and preparation method thereof

Abstract

The invention provides a phenolic amide epoxy curing agent and a preparation method thereof, and relates to the technical field of epoxy curing agents. The phenolic amide epoxy curing agent comprises cardanol, aldehyde, amine, dimer acid, polyethylene glycol diglycidyl ether and polyvinyl butyral. The polyethylene glycol diglycidyl ether and the polyvinyl butyral are added to interact with the cardanol, the aldehyde, the amine and the dimer acid, so that the toughness problem is effectively improved, the curing speed is high under the low-temperature condition, and the salt spray corrosion resistance is good.

Description

Technical Field

[0001] The invention relates to the technical field of epoxy curing agents, and in particular to a phenolic amide epoxy curing agent and a preparation method thereof. Background Art

[0002] Phenolic amide epoxy curing agent is a final product obtained by polycondensation reaction of phenolic compounds, aldehyde compounds and amine compounds, and then modified by addition, refining and other steps. Phenolic amide epoxy curing agent combines the technical advantages of phenolic amine and polyamide to overcome their respective limitations. Phenolic amide epoxy curing agent is widely used in industrial anti-corrosion coatings, adhesives, sealants and other fields.

[0003] However, although the existing phenolic amide epoxy curing agent can be cured under low temperature conditions, it still has problems such as insufficient toughness and poor salt spray corrosion resistance. Therefore, it is urgent to prepare a phenolic amide epoxy curing agent that can improve its toughness and salt spray corrosion resistance without affecting low temperature curing, which is of great significance for the widespread application of epoxy curing agents. Summary of the invention

[0004] Based on the technical problems existing in the background technology, the present invention provides a phenolic amide epoxy curing agent and a preparation method thereof.

[0005] The invention discloses a phenolic amide epoxy curing agent, which comprises cardanol, aldehyde, amine, dimer acid, polyethylene glycol diglycidyl ether and polyvinyl butyral.

[0006] Preferably, the aldehyde is selected from one or more of formaldehyde, paraformaldehyde and furanaldehyde.

[0007] Preferably, the amine is selected from one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine and polyethylenepolyamine.

[0008] Preferably, the dimer acid is derived from one or more of cottonseed oil, linseed oil, soybean oil and tall oil.

[0009] Preferably, the phenolic amide epoxy curing agent comprises the following raw materials in parts by mass: 100-200 parts of cardanol, 10-20 parts of aldehyde, 50-120 parts of amine, 150-350 parts of dimer acid, 3-10 parts of polyethylene glycol diglycidyl ether, and 5-10 parts of polyvinyl butyral.

[0010] The present invention also provides a method for preparing a phenolic amide epoxy curing agent, comprising the following steps:

[0011] S1, reacting dimer acid and amine at temperature T1 to obtain mixture A;

[0012] S2, adding cardanol and aldehyde to mixture A at temperature T2 for reaction, and vacuum dehydrating to obtain mixture B;

[0013] S3. At temperature T3, polyethylene glycol diglycidyl ether and polyvinyl butyral are added to mixture B, mixed evenly, and then cooled to room temperature to obtain a phenolic amide epoxy curing agent.

[0014] Preferably, in said S1, the reaction process of dimer acid and amine also includes a dehydration process.

[0015] Preferably, in said S1, the temperature T1 is 200-250°C.

[0016] Preferably, in said S2, the temperature T2 is 80-100°C.

[0017] Preferably, in said S3, the temperature of T3 is 50-80°C.

[0018] The beneficial effects of the present invention are:

[0019] The phenolic amide epoxy curing agent provided by the present invention comprises raw materials of cardanol, aldehyde, amine, dimer acid, polyethylene glycol diglycidyl ether, and polyvinyl butyral. The raw materials act synergistically, and the prepared phenolic amide epoxy curing agent has excellent low-temperature curing property, toughness, and salt spray corrosion resistance. In the present invention, polyethylene glycol diglycidyl ether and polyvinyl butyral are added to interact with cardanol, aldehyde, amine, and dimer acid, which not only effectively improves the toughness problem, but also has a fast curing speed and good salt spray corrosion resistance under low temperature conditions. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is described in detail through specific embodiments.

[0021] Unless otherwise specified, the materials, reagents, etc. used in the following examples and comparative examples can be obtained from commercial sources.

[0022] Example 1

[0023] A phenolic amide epoxy curing agent comprises the following raw materials in parts by weight: 160 parts of cardanol, 15 parts of paraformaldehyde, 50 parts of triethylenetetramine, 32 parts of diethylenetriamine, 160 parts of dimer acid, 5 parts of polyethylene glycol diglycidyl ether, and 8 parts of polyvinyl butyral.

[0024] A method for preparing a phenolic amide epoxy curing agent comprises the following steps:

[0025] S1. Add dimer acid and amine into a four-necked flask equipped with a stirrer, introduce nitrogen, and react at 235° C. for 2 h to obtain a mixture A;

[0026] S2, adjusting the temperature to 100° C., adding cardanol and aldehyde to mixture A, reacting for 2 h, and vacuum dehydrating to obtain mixture B;

[0027] S3. Adjust the temperature to 70° C., add polyethylene glycol diglycidyl ether and polyvinyl butyral to mixture B, mix well and cool to room temperature to obtain a phenolic amide epoxy curing agent.

[0028] Example 2

[0029] A phenolic amide epoxy curing agent comprises the following raw materials in parts by weight: 150 parts of cardanol, 12 parts of paraformaldehyde, 38 parts of diethylenetriamine, 55 parts of tetraethylenepentamine, 170 parts of dimer acid, 5 parts of polyethylene glycol diglycidyl ether, and 6 parts of polyvinyl butyral.

[0030] A method for preparing a phenolic amide epoxy curing agent comprises the following steps:

[0031] S1. Add dimer acid and amine into a four-necked flask equipped with a stirrer, introduce nitrogen, and react at 230° C. for 2 h to obtain a mixture A;

[0032] S2, adjusting the temperature to 100° C., adding cardanol and aldehyde to mixture A, reacting for 2 h, and vacuum dehydrating to obtain mixture B;

[0033] S3. Adjust the temperature to 65° C., add polyethylene glycol diglycidyl ether and polyvinyl butyral to mixture B, mix well and cool to room temperature to obtain a phenolic amide epoxy curing agent.

[0034] Example 3

[0035] A phenolic amide epoxy curing agent comprises the following raw materials in parts by weight: 180 parts of cardanol, 18 parts of paraformaldehyde, 50 parts of triethylenetetramine, 55 parts of tetraethylenepentamine, 158 parts of dimer acid, 6 parts of polyethylene glycol diglycidyl ether, and 6 parts of polyvinyl butyral.

[0036] A method for preparing a phenolic amide epoxy curing agent comprises the following steps:

[0037] S1. Add dimer acid and amine into a four-necked flask equipped with a stirrer, introduce nitrogen, and react at 230° C. for 2 h to obtain a mixture A;

[0038] S2, adjusting the temperature to 100° C., adding cardanol and aldehyde to mixture A, reacting for 2 h, and vacuum dehydrating to obtain mixture B;

[0039] S3. Adjust the temperature to 60° C., add polyethylene glycol diglycidyl ether and polyvinyl butyral to mixture B, mix well and cool to room temperature to obtain a phenolic amide epoxy curing agent.

[0040] Comparative Example 1

[0041] A phenolic amide epoxy curing agent comprises the following raw materials in parts by weight: 160 parts of cardanol, 15 parts of paraformaldehyde, 50 parts of triethylenetetramine, 32 parts of diethylenetriamine, and 160 parts of dimer acid.

[0042] A method for preparing a phenolic amide epoxy curing agent comprises the following steps:

[0043] S1. Add dimer acid and amine into a four-necked flask equipped with a stirrer, introduce nitrogen, and react at 235° C. for 2 h to obtain a mixture A;

[0044] S2. Adjust the temperature to 100° C., add cardanol and aldehyde to the mixture A and react for 2 hours, and vacuum dehydrate to obtain a phenolic amide epoxy curing agent.

[0045] Comparative Example 2

[0046] A phenolic amide epoxy curing agent comprises the following raw materials in parts by weight: 160 parts of cardanol, 15 parts of paraformaldehyde, 80 parts of triethylenetetramine, 160 parts of dimer acid, and 5 parts of polyethylene glycol diglycidyl ether.

[0047] A method for preparing a phenolic amide epoxy curing agent comprises the following steps:

[0048] S1. Add dimer acid and amine into a four-necked flask equipped with a stirrer, introduce nitrogen, and react at 235° C. for 2 h to obtain a mixture A;

[0049] S2, adjusting the temperature to 100° C., adding cardanol and aldehyde to mixture A, reacting for 2 h, and vacuum dehydrating to obtain mixture B;

[0050] S3. Adjust the temperature to 70° C., add polyethylene glycol diglycidyl ether to mixture B, mix well, and then cool to room temperature to obtain a phenolic amide epoxy curing agent.

[0051] The above-mentioned phenolic amide epoxy curing agent and epoxy primer were mixed at a mass ratio of 30:100 to prepare a paint film, and its pencil hardness was tested according to GB / T 6739-2022, its impact resistance was tested according to GB / T 1732-2020, and its salt spray resistance was tested according to GB / T 1771-2007, and the time of blistering at the scratch was recorded. The test results are shown in Table 1.

[0052] Table 1

[0053] Group Pencil hardness Impact resistance Salt spray resistance 45℃(h) Example 1 3H 50cm 1632 Example 2 3H 50cm 1584 Example 3 3H 50cm 1608 Comparative Example 1 3H 35cm 1080 Comparative Example 2 2H 40cm 1104

[0054] It can be seen from the data in Table 1 that the phenolic amide epoxy curing agent prepared by the present invention has high pencil hardness and excellent impact resistance and salt spray resistance. It can be seen from the data of Comparative Examples 1-2 and the Examples that the synergistic effect between the raw materials of the phenolic amide epoxy curing agent of the present invention and the scientific raw material ratio help to improve its hardness, impact resistance and salt spray resistance.

[0055] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A phenolic amide epoxy curing agent, characterized in that: Including cardanol, aldehyde, amine, dimer acid, polyethylene glycol diglycidyl ether, and polyvinyl butyral.

2. The phenolic amide epoxy curing agent according to claim 1, characterized in that The aldehyde is selected from one or more of formaldehyde, paraformaldehyde and furfural.

3. The phenolic amide epoxy curing agent according to claim 1, characterized in that The amine is selected from one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine and polyethylenepolyamine.

4. The phenolic amide epoxy curing agent according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 100-200 parts of cardanol, 10-20 parts of aldehyde, 50-120 parts of amine, 150-350 parts of dimer acid, 3-10 parts of polyethylene glycol diglycidyl ether and 5-10 parts of polyvinyl butyral.

5. A method for preparing the phenolic amide epoxy curing agent according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1, reacting dimer acid and amine at temperature T1 to obtain mixture A; S2, adding cardanol and aldehyde to mixture A at temperature T2 for reaction, and vacuum dehydrating to obtain mixture B; S3. At temperature T3, polyethylene glycol diglycidyl ether and polyvinyl butyral are added to mixture B, mixed evenly, and then cooled to room temperature to obtain a phenolic amide epoxy curing agent.

6. The preparation method according to claim 5, characterized in that: In the S1, the temperature T1 is 200-250°C.

7. The preparation method according to claim 5, characterized in that: In the S2, the temperature of T2 is 80-100°C.

8. The preparation method according to claim 5, characterized in that: In the S3, the temperature of T3 is 50-80°C.