A hexamethylenetetramine-based plant polyphenol aldehyde amine epoxy curing agent and a preparation method thereof

Abstract

The application discloses a kind of plant polyphenol amines based on hexamethylenetetramine epoxy curing agent, it is characterized in that, by weight parts, including: plant polyphenol 50-80 parts;Hexamethylenetetramine 5-15 parts;Amine 10-30 parts;Water 1-5 parts.The application also discloses a preparation method thereof.The application uses hexamethylenetetramine instead of paraformaldehyde, hexamethylenetetramine is white crystal, taste is small, pollution is small in use process, hydrolysis is generated formaldehyde and ammonia gas, ammonia gas is dissolved in water to form ammonia water, can be used as amine raw material.Use while reducing the use of amine substance, the water generated by condensation reaction continues to participate in the hydrolysis reaction of hexamethylenetetramine, and the generated water is basically consumed by reaction.

Description

Technical Field

[0001] This invention relates to the field of phenolic amine epoxy curing agent preparation, specifically to a plant polyene phenolic amine epoxy curing agent based on hexamethylenetetramine and its preparation method. Background Technology

[0002] Existing phenolic amine epoxy curing agents primarily use phenol, cashew phenol, and nonylphenol as phenolic raw materials, while a wide range of amine raw materials have been explored, including aliphatic amines, cyclic amines, aromatic amines, and modified amines. Aldehyde raw materials are mainly paraformaldehyde.

[0003] The main advantage is that by combining different of the aforementioned raw materials, the curing agent can be given different properties, thus expanding the market application range of the product.

[0004] However, the paraformaldehyde and formaldehyde aqueous solutions used in the traditional way are volatile, highly irritating, and carcinogenic. At the same time, in order to control the viscosity of the finished product, amine raw materials are generally used in excess. After being vacuum-extracted, a large amount of amine-containing wastewater is generated, most of which cannot be recycled and reused. In addition, the curing effect of the produced curing agent is not ideal. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the purpose of this invention is to provide a plant polyene phenolic amine epoxy curing agent based on hexamethylenetetramine and its preparation method.

[0006] This invention uses plant polyene phenols as the main phenol and hexamethylenetetramine to replace paraformaldehyde. Hexamethylenetetramine is hydrolyzed at high temperature to generate ammonia and formaldehyde. The ammonia dissolves in water to form ammonia water, which undergoes a Mannich reaction with other types of amines. The synthesized phenolic amine epoxy curing agent does not produce a large amount of amine-containing wastewater and can meet the curing standards.

[0007] To achieve the objectives of this invention, the technical solution adopted is as follows:

[0008] A plant-based polyene phenolic amine epoxy curing agent based on hexamethylenetetramine, comprising, by weight:

[0009] 50-80 parts of plant polyenes;

[0010] 5-15 parts of hexamethylenetetramine;

[0011] 10-30 parts of amine;

[0012] 1-5 parts water.

[0013] In a preferred embodiment of the present invention, the plant polyene phenolic amine epoxy curing agent based on hexamethylenetetramine comprises, by weight:

[0014] 60-80 parts of plant polyenes;

[0015] 5-15 parts of hexamethylenetetramine;

[0016] 10-25 parts of amine;

[0017] 1-5 parts water.

[0018] In a preferred embodiment of the present invention, the amine is any one or more of aliphatic amines, alicyclic amines, or aromatic amines.

[0019] In a preferred embodiment of the present invention, the plant polyene phenol is any one or more of cashew phenol, cardiotonic phenol, and methyl cardiotonic phenol.

[0020] In a preferred embodiment of the present invention, the cashew phenol comprises any one or more of 3-pentadecanylphenol, 3-(8-pentadecanyl)phenol, or 3-(8,11-pentadecanadienyl)phenol.

[0021] In a preferred embodiment of the present invention, the cardiac glycoside comprises any one or more of 5-pentadecanyl-1,3-benzenediol, 5-(8-pentadecanyl)-1,3-benzenediol, or 5-(8,11-pentadecanediol)-1,3-resorcinol.

[0022] In a preferred embodiment of the present invention, the methyl cardiac glycoside comprises any one or more of 2-methyl-5-pentadecanyl-1,3-benzenediol, 2-methyl-5-(8-pentadecanyl)-1,3-benzenediol, or 2-methyl-5-(8,11-pentadecanyl)-1,3-benzenediol.

[0023] A method for preparing a plant-based polyene phenolic amine epoxy curing agent based on hexamethylenetetramine, wherein the preparation method is shown in formulas 1, 2, and 3 below:

[0024]

[0025] in,

[0026] n = 0, 1, or 2;

[0027] H2N-R-NH2 is any one or more of aliphatic amines, alicyclic amines, or aromatic amines;

[0028] -R1 is (-NH2)n1 or (-HN-R-NH2)n1, where n1 = 0 or 1;

[0029] -R2 is either (-NH2)n2 or (-HN-R-NH2)n2, n2 = 0 or 1; n1 and n2 cannot be equal to 0 at the same time;

[0030]

[0031] in,

[0032] n = 0, 1, or 2;

[0033] M = 1, 2, or 3;

[0034] H2N-R-NH2 is any one or more of aliphatic amines, alicyclic amines, or aromatic amines;

[0035] -R1 is (-NH2)n1 or (-HN-R-NH2)n1, n1 = 1;

[0036]

[0037] in,

[0038] n = 0, 1, or 2;

[0039] H2N-R-NH2 is any one or more of aliphatic amines, alicyclic amines, or aromatic amines;

[0040] -R1 is (-NH2)n1 or (-HN-R-NH2)n1, where n1 = 0 or 1;

[0041] -R2 is (-NH2)n2 or (-HN-R-NH2)n2, n2 = 0 or 1; n1 and n2 cannot be equal to 0 at the same time.

[0042] A method for preparing a plant-based polyene phenolic amine epoxy curing agent based on hexamethylenetetramine includes the following steps:

[0043] After mixing the plant polyenes, amines and water until homogeneous, gradually raise the temperature to 70-80℃.

[0044] Add hexamethylenetetramine under stirred reflux, then heat to 90-105℃, maintain reflux for 3-6 hours, cool to room temperature, filter and discharge.

[0045] In a preferred embodiment of the present invention, the hexamethylenetetramine is added intermittently, slowly continuously, or in a single application.

[0046] The beneficial effects of this invention are as follows:

[0047] Hexamethylenetetramine is used to replace paraformaldehyde in the Mannich-type reaction. The hydrolysis of hexamethylenetetramine not only produces formaldehyde, but also NH3, forming ammonia water, which can also participate in the Mannich-type reaction, reducing the use of amine raw materials.

[0048] Meanwhile, the water generated in the reaction is used in the hydrolysis of hexamethylenetetramine at a molar ratio of 1:1. The water produced is basically consumed by the reaction, resulting in very little final amine-containing wastewater that is easy to treat and environmentally friendly. Detailed Implementation

[0049] Example 1:

[0050] In a 1L four-necked flask equipped with a stirrer, add 600g of plant polyene phenols, 102g of pentanediamine, and 12g of water. Start the stirrer, reflux the mixture, and heat to 70°C. Slowly add 56g of hexamethylenetetramine. After the addition is complete, slowly heat to 95°C and maintain this temperature under reflux for 3 hours. Slowly heat to 145°C and maintain this temperature for 3 hours. Discharge the material after cooling to room temperature.

[0051] Example 2:

[0052] In a 1L four-necked flask equipped with a stirrer, add 600g of plant polyene phenols, 153g of pentanediamine, and 26g of water. Start stirring, reflux, and heat to 70°C. Slowly add 70g of hexamethylenetetramine. After addition, slowly heat to 95°C and reflux for 3 hours. Slowly heat to 145°C and recover for 3 hours. Cool to room temperature and discharge.

[0053] Example 3:

[0054] In a 1L four-necked flask equipped with a stirrer, add 600g of plant polyene phenols, 204g of pentanediamine, and 46g of water. Start stirring, reflux, and heat to 70°C. Slowly add 98g of hexamethylenetetramine. After addition, slowly heat to 95°C and reflux for 3 hours. Slowly heat to 145°C and reflux for 3 hours. Cool to room temperature and discharge.

[0055] Comparative Example 1:

[0056] In a 1L four-necked flask equipped with a stirrer, add 600g of plant polyene phenols, 204g of pentamethylenediamine, and 46g of water. Start the stirrer, reflux the mixture, and heat to 70°C. Slowly add 200g of hexamethylenetetramine. After the addition is complete, slowly heat to 95°C and reflux for 3 hours. Slowly heat to 145°C and reflux for 3 hours. Discharge the material after cooling to room temperature.

[0057] Comparative Example 2:

[0058] Plant polyene phenolic amine curing agent, model PLR712, is produced by Changshu Naisu Biomaterials Technology Co., Ltd.

[0059] The experimental results and application test results of Examples 1-3 and Comparative Examples 1-2 are shown in Table 1 below:

[0060] Table 1

[0061]

[0062] As can be seen from Table 1, in terms of synthesis, the amount of waste amine water produced by the epoxy curing agent prepared in Examples 1-3 of the present invention is less than 1% more than the amount of water added initially, and the amine value is only more than 20, so it can be discharged with little or no treatment.

[0063] Unlike traditional paraformaldehyde, which produces a large amount of water from the condensation reaction carrying excessive amines, accounting for 10-30% of the total formulation, this paraformaldehyde is distilled off.

[0064] In terms of application testing, the mechanical properties meet the general requirements of the coating.

[0065] This invention uses hexamethylenetetramine instead of paraformaldehyde. Hexamethylenetetramine is a white crystal with little odor and causes little pollution during use. It hydrolyzes to produce formaldehyde and ammonia. The ammonia dissolves in water to form ammonia water, which can be used as an amine raw material.

[0066] The formulation of this invention reduces the use of amines while allowing the water generated by the condensation reaction to continue participating in the hydrolysis reaction of hexamethylenetetramine, with the water produced being essentially consumed by the reaction.

[0067] The final amount of waste amine water is very small, with low nitrogen content, easy to treat, and has little environmental impact.

Claims

1. A method for preparing a plant polyene phenolic amine epoxy curing agent based on hexamethylenetetramine, characterized in that, Includes the following steps: After mixing plant polyenes, amines and water until homogeneous, gradually raise the temperature to 70-80℃. Hexamethylenetetramine is added under stirred reflux conditions, then heated to 90-105°C, kept at that temperature under reflux for 3-6 hours, cooled to room temperature, filtered, and discharged. The hexamethylenetetramine is added intermittently, slowly continuously, or all at once. The amine is pentamethylenediamine; The plant polyene phenol is any one or more of cashew phenol, cardiac phenol, and methyl cardiac phenol; The cashew phenol is any one or more of 3-pentadecanylphenol, 3-(8-pentadecanenyl)-phenol or 3-(8,11-pentadecanadienyl)-phenol; The cardiac glycoside is any one or more of 5-pentadecanyl-1,3-benzenediol, 5-(8-pentadecanyl)-1,3-benzenediol or 5-(8,11-pentadecanediol)-1,3-benzenediol. The methyl cardiac glycophenol is any one or more of 2-methyl-5-pentadecanyl-1,3-benzenediol, 2-methyl-5-(8-pentadecanyl)-1,3-benzenediol or 2-methyl-5-(8,11-pentadecanyl)-1,3-benzenediol; The plant polyene phenols are 50-80 parts by weight; The hexamethylenetetramine is present in 5-15 parts; The amine is in the form of 10-30 parts; The amount of water is 1-5 parts.

2. The preparation method of a plant polyene phenolic amine epoxy curing agent based on hexamethylenetetramine as described in claim 1, characterized in that, The plant polyene phenols are 60-80 parts; The amine is in the form of 10-25 parts.

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