阅读说明：本技术 一种新型环氧树脂固化剂的制备方法 (Preparation method of novel epoxy resin curing agent ) 是由 施中新 胡胜初 张凯铭 王晓东 樊莹 黄晓龙 康圆圆 顾俊 黄晟煜 于 2020-12-29 设计创作，主要内容包括：本发明提供一种新型环氧树脂固化剂的制备方法,固化剂通过将烷基酚和甲醛缩合,然后与多元胺加成反应,最后通过封端剂封端改性而成；新型环氧树脂固化剂的制备方法,包括以下步骤：(1)将烷基酚加热至50-60℃,然后加入质量浓度为37％-40％甲醛溶液,反应4-5h,得到第一混合物；(2)将第一混合物中加入多元胺,反应6-8h,然后将第一混合物升温至100℃,向其中加入封端剂,反应9-10h,得到所述新型环氧树脂固化剂。本发明的新型水型环氧树脂固化剂,可在较低温度下快速固化环氧树脂,并适用于含水条件下的固化反应。(The invention provides a preparation method of a novel epoxy resin curing agent, wherein the curing agent is prepared by condensing alkylphenol and formaldehyde, then carrying out addition reaction with polyamine, and finally carrying out end capping modification by using a capping agent; the preparation method of the novel epoxy resin curing agent comprises the following steps: (1) heating alkylphenol to 50-60 ℃, adding a formaldehyde solution with the mass concentration of 37-40%, and reacting for 4-5h to obtain a first mixture; (2) and adding polyamine into the first mixture, reacting for 6-8h, heating the first mixture to 100 ℃, adding a blocking agent into the first mixture, and reacting for 9-10h to obtain the novel epoxy resin curing agent. The novel water-type epoxy resin curing agent can rapidly cure epoxy resin at a lower temperature and is suitable for curing reaction under a water-containing condition.)

1. A preparation method of a novel epoxy resin curing agent is characterized by comprising the following steps: the curing agent is prepared by condensing alkylphenol and formaldehyde, then carrying out addition reaction with polyamine, and finally carrying out end capping modification by using an end capping agent;

the preparation method of the novel epoxy resin curing agent comprises the following steps:

(1) heating alkylphenol to 50-60 ℃, adding a formaldehyde solution with the mass concentration of 37-40%, and reacting for 4-5h to obtain a first mixture;

(2) and adding polyamine into the first mixture, reacting for 6-8h, heating the first mixture to 100 ℃, adding a blocking agent into the first mixture, and reacting for 9-10h to obtain the novel epoxy resin curing agent.

2. The method for preparing a novel epoxy resin curing agent according to claim 1, characterized in that: the alkylphenol in the step (1) is one or a mixture of two of cardanol, carvacrol and dodecylphenol.

3. The method for preparing a novel epoxy resin curing agent according to claim 1, characterized in that: the molar ratio of the alkylphenol to the formaldehyde in the step (1) is 1: 0.9-1.1.

4. The method for preparing a novel epoxy resin curing agent according to claim 1, characterized in that: the polyamine in the step (2) is any one or a mixture of two of dodecyl dipropylene triamine, diethylene triamine and N-oleyl-1, 3-propane diamine.

5. The method for preparing a novel epoxy resin curing agent according to claim 1, characterized in that: the end-capping reagent in the step (2) is any one or a mixture of two of glycidyl butyl ether, glycidyl allyl ether and glycidyl phenyl ether.

6. The method for preparing a novel epoxy resin curing agent according to claim 1, characterized in that: the molar ratio of the alkylphenol to the polyamine is 1:1-1.5, and the molar ratio of the alkylphenol to the end-capping reagent is 1: 0.5-1.

Technical Field

The invention relates to the technical field of epoxy resin, in particular to a preparation method of a novel epoxy resin curing agent.

Background

Epoxy resin is a commonly used resin material and is widely applied to the fields of automobiles, ships, electronic power, buildings, packaging and the like, however, pure epoxy resin has little practical value, a series of excellent performances can be presented only by changing the epoxy resin into a three-dimensional network structure through modification, and a curing agent is commonly used for modifying the epoxy resin and directly reacts with the epoxy resin to realize the change of the epoxy resin into the three-dimensional network structure, so that the structure and the quality of the curing agent are very important, and the application effect of the epoxy resin is directly influenced.

At present, the commonly used epoxy resin curing agents mainly comprise aliphatic amine curing agents, anhydride curing agents, phenolic aldehyde amine curing agents and the like, and the aliphatic amine curing agents are high in dosage, but are poor in brittleness, impact resistance and weather resistance and high in toxicity, so that the application of the epoxy resin curing agents is limited to a certain extent. Anhydride curing agents have long pot life and storage stability, but are difficult to chemically modify, have long cure times, and have poor moisture resistance. The phenolic aldehyde amine curing agent is generally prepared by performing Mannich addition reaction on phenol, formaldehyde and polyamine, has good reaction activity, can be used for curing epoxy resin in a normal-temperature environment and a high-humidity environment, but has short service life, insufficient elasticity or toughness and unsatisfactory water resistance and seawater resistance.

Aiming at the defects of the existing curing agent, the curing agent which is environment-friendly, can realize the rapid curing of the epoxy resin at a lower temperature and is suitable for the conditions of water and seawater is very urgent.

Disclosure of Invention

The invention aims to overcome and supplement the defects in the prior art, and provides a preparation method of a novel epoxy resin curing agent, which can quickly cure epoxy resin at a lower temperature and is suitable for curing reaction under a water-containing condition. The technical scheme adopted by the invention is as follows:

a method for preparing a novel epoxy resin curing agent, wherein: the curing agent is prepared by condensing alkylphenol and formaldehyde, then carrying out addition reaction with polyamine, and finally carrying out end capping modification by using an end capping agent;

the preparation method of the novel epoxy resin curing agent specifically comprises the following steps:

(1) heating alkylphenol to 50-60 ℃, adding a formaldehyde solution with the mass concentration of 37-40%, and reacting for 4-5h to obtain a first mixture;

(2) and adding polyamine into the first mixture, reacting for 6-8h, heating the first mixture to 100 ℃, adding a blocking agent into the first mixture, and reacting for 9-10h to obtain the novel epoxy resin curing agent.

Preferably, the preparation method of the novel epoxy resin curing agent comprises the following steps: the alkylphenol in the step (1) is one or a mixture of two of cardanol, carvacrol and dodecylphenol.

Preferably, the preparation method of the novel epoxy resin curing agent comprises the following steps: the molar ratio of the alkylphenol to the formaldehyde in the step (1) is 1: 0.9-1.1.

Preferably, the preparation method of the novel epoxy resin curing agent comprises the following steps: the polyamine in the step (2) is any one or a mixture of two of dodecyl dipropylene triamine, diethylene triamine and N-oleyl-1, 3-propane diamine.

Preferably, the preparation method of the novel epoxy resin curing agent comprises the following steps: the end-capping reagent in the step (2) is any one or a mixture of two of glycidyl butyl ether, glycidyl allyl ether and glycidyl phenyl ether.

Preferably, the preparation method of the novel epoxy resin curing agent comprises the following steps: the molar ratio of the alkylphenol to the polyamine is 1:1-1.5, and the molar ratio of the alkylphenol to the end-capping reagent is 1: 0.5-1.

The invention has the advantages that: the novel water-type epoxy resin curing agent can rapidly cure epoxy resin at a lower temperature, is suitable for curing reaction under a water-containing condition, has a simple preparation process, easily-obtained raw materials, is convenient to popularize and popularize, is environment-friendly, can rapidly cure epoxy resin at a low temperature of 0 ℃, and can rapidly cure epoxy resin under the water-containing condition.

Detailed Description

The present invention will be further described with reference to the following specific examples.

Example 1:

a method for preparing a novel epoxy resin curing agent, wherein: the curing agent is prepared by condensing alkylphenol and formaldehyde, then carrying out addition reaction with polyamine, and finally carrying out end capping modification by using an end capping agent;

the preparation method of the novel epoxy resin curing agent comprises the following steps:

putting 1mol of cardanol into a reaction kettle, heating to 50 ℃, adding 0.9mol of formaldehyde solution with the concentration of 37%, reacting for 4 hours to obtain a first mixture, dropwise adding 1mol of diethylenetriamine into the first mixture, reacting for 6 hours, raising the temperature of the first mixture to 90 ℃, adding 0.5mol of glycidyl butyl ether, and reacting for 9 hours to obtain the curing agent.

Example 2:

a method for preparing a novel epoxy resin curing agent, wherein: the curing agent is prepared by condensing alkylphenol and formaldehyde, then carrying out addition reaction with polyamine, and finally carrying out end capping modification by using an end capping agent;

the preparation method of the novel epoxy resin curing agent comprises the following steps:

putting 1mol of carvacrol into a reaction kettle, heating to 60 ℃, adding 1.1mol of 40% formaldehyde solution, reacting for 5 hours to obtain a first mixture, dropwise adding 1.5mol of dodecyl dipropylene triamine into the first mixture, and reacting for 8 hours. The temperature of the first mixture was then raised to 100 ℃ and 1mol of glycidyl allyl ether was added and reacted for 10h to obtain a curing agent.

Example 3:

a method for preparing a novel epoxy resin curing agent, wherein: the curing agent is prepared by condensing alkylphenol and formaldehyde, then carrying out addition reaction with polyamine, and finally carrying out end capping modification by using an end capping agent;

the preparation method of the novel epoxy resin curing agent comprises the following steps:

putting 1mol of dodecylphenol into a reaction kettle, heating to 55 ℃, adding 1mol of formaldehyde solution with the concentration of 38%, reacting for 4.5h to obtain a first mixture, dropwise adding 1.3mol of N-oleyl-1, 3-propane diamine into the first mixture, reacting for 7h, raising the temperature of a reaction system in the first mixture to 95 ℃, adding 0.75mol of glycidyl phenyl ether, and reacting for 9.5h to obtain the curing agent.

Example 4:

a method for preparing a novel epoxy resin curing agent, wherein: the curing agent is prepared by condensing alkylphenol and formaldehyde, then carrying out addition reaction with polyamine, and finally carrying out end capping modification by using an end capping agent;

the preparation method of the novel epoxy resin curing agent comprises the following steps:

putting 0.5mol of cardanol and 0.5mol of carvacrol into a reaction kettle, heating to 60 ℃, adding 1mol of formaldehyde solution with the concentration of 37%, reacting for 5 hours to obtain a first mixture, dropwise adding 1mol of diethylenetriamine and 0.5mol of N-oleyl-1, 3-propanediamine into the first mixture, reacting for 8 hours, then raising the temperature of a reaction system of the first mixture to 100 ℃, adding 0.5mol of glycidyl butyl ether and 0.5mol of glycidyl allyl ether, and reacting for 10 hours to obtain the curing agent.

Example 5:

a method for preparing a novel epoxy resin curing agent, wherein: the curing agent is prepared by condensing alkylphenol and formaldehyde, then carrying out addition reaction with polyamine, and finally carrying out end capping modification by using an end capping agent;

the preparation method of the novel epoxy resin curing agent comprises the following steps:

putting 0.5mol of cardanol and 0.5mol of dodecylphenol into a reaction kettle, heating to 60 ℃, adding 1mol of formaldehyde solution with the concentration of 37%, reacting for 5 hours to obtain a first mixture, dropwise adding 1mol of diethylenetriamine and 0.5mol of dodecyldipropylenetriamine into the first mixture, reacting for 8 hours, then raising the temperature of a reaction system of the first mixture to 100 ℃, adding 0.5mol of glycidyl butyl ether and 0.5mol of glycidyl phenyl ether, and reacting for 10 hours to obtain the curing agent.

Example 6:

a method for preparing a novel epoxy resin curing agent, wherein: the curing agent is prepared by condensing alkylphenol and formaldehyde, then carrying out addition reaction with polyamine, and finally carrying out end capping modification by using an end capping agent;

the preparation method of the novel epoxy resin curing agent comprises the following steps:

putting 0.5mol of carvacrol and 0.5mol of dodecylphenol into a reaction kettle, heating to 60 ℃, adding 1mol of formaldehyde solution with the concentration of 37%, reacting for 5 hours to obtain a first mixture, dropwise adding 1mol of dodecyldipropylenetriamine and 0.5mol of N-oleyl-1, 3-propanediamine into the first mixture, reacting for 8 hours, then raising the temperature of a reaction system of the first mixture to 100 ℃, adding 0.5mol of glycidyl allyl ether and 0.5mol of glycidyl phenyl ether, and reacting for 10 hours to obtain the curing agent.

Comparative example 1:

putting 1mol of cardanol into a reaction kettle, heating to 50 ℃, adding 0.9mol of formaldehyde solution with the concentration of 37%, reacting for 4 hours to obtain a first mixture, dropwise adding 0.7mol of diethylenetriamine into the first mixture, reacting for 6 hours, raising the temperature of a reaction system to 90 ℃, adding 0.5mol of glycidyl butyl ether, and reacting for 9 hours to obtain the curing agent.

Comparative example 2:

putting 1mol of cardanol into a reaction kettle, heating to 50 ℃, adding 0.9mol of formaldehyde solution with the concentration of 37%, reacting for 4 hours to obtain a first mixture, dropwise adding 0.5mol of diethylenetriamine into the first mixture, reacting for 6 hours, raising the temperature of a reaction system to 90 ℃, adding 1.5mol of glycidyl butyl ether, and reacting for 9 hours to obtain the curing agent.

And (3) performance testing:

comparing the application effects of the curing agent of examples 1-6 of the present invention and the curing agent of comparative examples 1-2 and the commercial curing agent in the curing of bisphenol A epoxy resin, the curing agent and the epoxy resin were weighed respectively according to the mass ratio (the curing agent: the epoxy resin: 1:3), mixed uniformly, coated uniformly with tin plate as a base material to form a paint film with a thickness of about 0.2mm, and the surface drying time of the epoxy resin paint film in 25 ℃ anhydrous condition, 0 ℃ anhydrous condition, 25 ℃ pure water and 25 ℃ seawater was examined respectively, and the test results are shown in Table 1.

TABLE 1 tack-free time of epoxy resin films under the action of different curing agents

Examples	Anhydrous condition at 25 deg.C	Anhydrous condition at 0 DEG C	Pure water at 25 DEG C	25 deg.C seawater
					Example 1	35min	45min	35min	37min
Example 2	33min	39min	38min	41min
					Example 3	37min	41min	42min	39min
Example 4	39min	45min	41min	47min
					Example 5	36min	43min	36min	40min
Example 6	36min	40min	43min	45min
					Comparative example 1	75min	123min	144min	145min
Comparative example 2	69min	155min	143min	141min
					Is commercially available	96min	Over 3 hours	Over 3 hours	Over 3 hours

As can be seen from Table 1, the epoxy resin curing agents of examples 1 to 6 and the epoxy resins were uniformly mixed, and the tack-free time of the coating film at 25 ℃ under anhydrous condition was 33 to 39min, while the tack-free time of comparative examples 1 to 2 was 69 to 75min, and the tack-free time of the commercially available curing agent was 96min, indicating that the tack-free time of the curing agents of examples 1 to 6 was better than that of the curing agents of comparative examples 1 to 2 and the commercially available curing agent, and that the curing agents of comparative examples 1 to 2 were better than that of the commercially available curing agent; the epoxy resin curing agents and epoxy resins of examples 1-6 were mixed uniformly, the surface drying time of the coating film under the anhydrous condition at 0 ℃ was 39-45min, the surface drying time of comparative examples 1-2 was 123-155min, and the surface drying time of the commercially available curing agent was 3h or more, indicating that the surface drying time of the curing agents of examples 1-6 was better than that of the curing agents of comparative examples 1-2 and commercially available curing agents, and that the curing agents of comparative examples 1-2 were better than that of the commercially available curing agents; the epoxy resin curing agents of examples 1 to 6 and the epoxy resins were uniformly mixed, the surface drying time of the coating film in pure water at 25 ℃ was 35 to 43min, the surface drying time of comparative examples 1 to 2 was 143 to 144min, and the surface drying time of the commercially available curing agents was 3 hours or more, indicating that the surface drying time of the curing agents of examples 1 to 6 was superior to that of the curing agents of comparative examples 1 to 2 and the commercially available curing agents, and that the curing agents of comparative examples 1 to 2 were superior to that of the commercially available curing agents; the epoxy resin curing agent and the epoxy resin of examples 1 to 6 were mixed uniformly, the surface drying time of the coating film in seawater at 25 ℃ was 37 to 47min, while the surface drying time of the comparative examples 1-2 is 141-145min, and the surface drying time of the commercially available curing agent is more than 3h, which shows that the surface drying time of the curing agent of the examples 1-6 is better than that of the curing agent of the comparative examples 1-2 and the commercially available curing agent, the curing agents of comparative examples 1 to 2 are superior to the commercially available curing agents, and from the above results, it can be seen that the novel water-type epoxy resin curing agent of the present invention, can quickly cure epoxy resin at lower temperature, is suitable for curing reaction under the condition of water content, has simple preparation process, easily obtained raw materials, convenient popularization and environmental protection, the epoxy resin can be quickly cured at the low temperature of 0 ℃, and the novel curing agent can realize the quick curing of the epoxy resin under the water-containing condition.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.