阅读说明：本技术 水溶型自乳化酚醛改性胺水性环氧固化剂及其制备方法 (Water-soluble self-emulsifying phenolic aldehyde modified amine water-based epoxy curing agent and preparation method thereof ) 是由 杨凯华 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种水溶型自乳化酚醛改性胺水性环氧固化剂及其制备方法,该水性环氧固化剂以苯酚或苯酚衍生物、多聚甲醛、多元胺为起始原料,经曼尼希反应后,加入环氧树脂和多元醇缩水甘油醚类改性剂进行扩链反应后,加入去离子水而获得最终产品。本发明通过在环氧固化剂中引入环氧树脂分子链段,提高了固化剂与环氧树脂的相容性,并且水性环氧固化剂与液体环氧树脂固化使用时,还具有自乳化液体环氧树脂的功能。加入多元醇缩水甘油醚类改性剂,增加了亲水基团,使本水性环氧固化剂具有很好的水溶性。(The invention discloses a water-soluble self-emulsifying phenolic aldehyde modified amine water-based epoxy curing agent and a preparation method thereof. The invention improves the compatibility of the curing agent and the epoxy resin by introducing the epoxy resin molecular chain segment into the epoxy curing agent, and the waterborne epoxy curing agent also has the function of self-emulsifying liquid epoxy resin when being used for curing with the liquid epoxy resin. The polyhydric alcohol glycidyl ether modifier is added, so that hydrophilic groups are added, and the water-based epoxy curing agent has good water solubility.)

1. A water-soluble self-emulsifying phenolic aldehyde modified amine water-based epoxy curing agent is characterized by comprising the following raw materials of phenol and phenol derivatives, polyamine, paraformaldehyde, epoxy resin and polyol glycidyl ether in a molar ratio of 1 (0.1-2.0) (0.1-1.0) (0.01-0.2).

2. The water-soluble self-emulsifying phenol-aldehyde modified amine water-based epoxy hardener as claimed in claim 1, wherein the phenol derivative is cardanol.

3. The water-soluble self-emulsifying phenolic aldehyde modified amine waterborne epoxy hardener as claimed in claim 1, wherein the polyamine is at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and m-xylylenediamine.

4. The water-soluble self-emulsifying phenolic aldehyde modified amine water-based epoxy hardener as claimed in claim 1, wherein the epoxy equivalent of the epoxy resin is 100-1000.

5. The water-soluble self-emulsifying phenolic-modified amine waterborne epoxy hardener as claimed in claim 4, wherein the epoxy resin is at least one of E51, E44, E20, E54 and EPON 828.

6. The water-soluble self-emulsifying phenol-aldehyde-modified amine waterborne epoxy hardener as claimed in claim 1, wherein the polyol glycidyl ether is at least one of ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polybutylene glycol diglycidyl ether.

7. The preparation method of the water-soluble self-emulsifying phenolic aldehyde modified amine water-soluble epoxy hardener as claimed in any one of claims 1 to 6, which is characterized by comprising the following steps:

s1, uniformly mixing phenol, a phenol derivative, polyamine and paraformaldehyde, heating to 60-90 ℃, and reacting for 2-8 hours in a heat preservation manner;

s2, adding epoxy resin and polyhydric alcohol glycidyl ether, and reacting for 4-8 h;

and S3, adding deionized water, and uniformly stirring to obtain the water-soluble self-emulsifying phenolic aldehyde modified amine waterborne epoxy curing agent.

8. The preparation method of the water-soluble self-emulsifying phenolic aldehyde modified amine waterborne epoxy hardener as claimed in claim 7, wherein the amine value of the waterborne epoxy hardener is 130-150 mgKOH/g, and the solid content is 30-80%.

9. The use of the water-soluble self-emulsifying phenol-formaldehyde modified amine water-borne epoxy hardener as claimed in any one of claims 1 to 6 for preparing epoxy resin coatings.

Technical Field

The invention belongs to the field of epoxy resin curing agents, and particularly relates to a water-soluble self-emulsifying phenolic aldehyde modified amine water-based epoxy curing agent and a preparation method thereof.

Background

Due to the advantages of high mechanical property, low curing shrinkage, excellent chemical resistance, good processability, good adhesion to a plurality of substrates and the like, the epoxy resin is widely applied to the fields of composite materials, adhesives, coatings and the like. Wherein, the epoxy resin consumed by the production of the coating accounts for about 40 percent of the total consumption of the epoxy resin, and is the most important application field of the epoxy resin. The high-viscosity epoxy resin is convenient to construct only by adding a solvent or a diluent, and most of organic solvents and diluents are harmful to human bodies, so that the organic solvent-free epoxy resin, especially the water-based epoxy resin, has attracted attention very early. In recent years, with the issuance and implementation of a series of environmental regulations, HSE management is more strict, the traditional solvent-based epoxy coating with high volatility organic compound is not suitable for the development of the environment-friendly society, and the water-based epoxy coating system is receiving more attention. Therefore, in recent years, the waterborne epoxy coating is a pursuit target for transforming the traditional enterprises to high-tech products and improving the added value of the products. Under the action of the driving force, the demand of the waterborne epoxy curing agent is increasing, and the industry of the waterborne epoxy curing agent is developed vigorously.

The water-based epoxy curing agent commonly used in the market is ionic, and the water-based epoxy curing agent is mostly neutralized into salt by using organic acid (such as acetic acid). The existence of organic acid is easy to generate flash rust when being used on metal, thereby causing the performance of the coating to be reduced; in addition, the cationic water-based epoxy curing agent added with organic acid salt is sensitive to pH value, and is easy to have instability phenomenon when used together with some basic pigments and fillers. There are also a small number of nonionic aqueous epoxy curing agents on the market, and although the performance is improved compared to the ionic aqueous epoxy curing agents, there are many disadvantages in the overall application, such as poor storage stability, poor water resistance, and the like.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a water-soluble self-emulsifying phenolic aldehyde modified amine water-based epoxy curing agent. The curing agent does not need to be added with organic acid for neutralization and salification, the preparation process is simple, the reaction conditions are mild, and the application performance of the curing agent can reach the level of an oily epoxy curing agent.

In order to achieve the purpose, the invention adopts the following technical scheme:

a water-soluble self-emulsifying phenolic aldehyde modified amine water-based epoxy curing agent is characterized by comprising the following raw materials of phenol and phenol derivatives, polyamine, paraformaldehyde, epoxy resin and polyol glycidyl ether in a molar ratio of 1 (0.1-2.0) (0.1-1.0) (0.01-0.2).

Preferably, the phenol derivative is cardanol.

Preferably, the polyamine is at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and m-xylylenediamine.

Preferably, the epoxy equivalent of the epoxy resin is 100 to 1000.

Preferably, the epoxy resin is at least one of E51, E44, E20, E54 and EPON 828.

Preferably, the polyhydric alcohol glycidyl ether is at least one of ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether.

The invention also aims to provide a preparation method of the water-soluble self-emulsifying phenolic aldehyde modified amine water-soluble epoxy curing agent, which comprises the following steps:

s1, uniformly mixing phenol, a phenol derivative, polyamine and paraformaldehyde, heating to 60-90 ℃, and carrying out heat preservation reaction for 2-8 hours to obtain a Mannich base;

s2, adding epoxy resin and polyhydric alcohol glycidyl ether, and reacting for 4-8 h;

and S3, adding deionized water, and uniformly stirring to obtain the water-soluble self-emulsifying phenolic aldehyde modified amine waterborne epoxy curing agent.

The amine value of the waterborne epoxy curing agent prepared by the method is 130-150 mgKOH/g, and the solid content is 30-80%.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention uses phenol derivatives, polyamine and paraformaldehyde as raw materials, and the prepared water-soluble self-emulsifying phenolic aldehyde modified amine waterborne epoxy hardener has good drying property and flexibility due to the existence of phenolic hydroxyl and double-bond long-chain alkyl, and the chemical corrosion resistance of the hardener is greatly improved.

(2) According to the invention, through adopting the polyol glycidyl ether and the epoxy resin to carry out chain extension reaction on the Mannich base, a flexible polyether chain segment and a lipophilic epoxy chain segment which have hydrophilicity are introduced into the molecules of the curing agent, so that the water solubility of the curing agent is improved, and the compatibility of the curing agent in the epoxy resin is also improved.

(3) The water-soluble self-emulsifying phenolic aldehyde modified amine waterborne epoxy curing agent prepared by the one-step chain extension method has the advantages of simple preparation process and strong operability.

Detailed Description

The technical solutions of the present invention will be described in detail and fully with reference to the following specific embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.

Example 1

On a 1000ml reaction barrel, a stirrer, a condenser, a water separator, a thermometer and a feed inlet are arranged, 93g of phenol and 35g of ethylenediamine are added, the mixture is stirred uniformly, 35g of paraformaldehyde is added, the temperature is controlled to be 60-90 ℃, 10g of epoxy resin EPON828 is added after heat preservation is carried out for 6h, the mixture is stirred for 5h, 30g of ethylene glycol diglycidyl ether is added, the mixture is stirred for 5h, 250g of deionized water is added, the mixture is stirred uniformly, and finally the mixture is cooled and discharged, so that the clear, transparent and uniform water-soluble self-emulsifying phenolic aldehyde modified amine waterborne epoxy curing agent is obtained.

Example 2

A1000 ml reaction barrel is provided with a stirrer, a condenser, a water separator, a thermometer and a charging hole, 300g of cardanol and 50g of diethylenetriamine are added, the mixture is stirred uniformly, 38g of paraformaldehyde is added, the temperature is controlled to be 60-90 ℃, after heat preservation is carried out for 6h, 80g of epoxy resin E20 is added, stirring is carried out for 5h, 50g of polyethylene glycol diglycidyl ether is added, stirring is carried out for 5h, 250g of deionized water is added, stirring is carried out uniformly, and finally cooling discharging is carried out to obtain the clear, transparent and uniform water-soluble self-emulsifying phenolic aldehyde modified amine waterborne epoxy curing agent.

Example 3

And (2) adding 93g of phenol and 80g of triethylene tetramine into a 1000ml reaction barrel with a stirrer, a condenser, a water separator, a thermometer and a charging opening, uniformly stirring, adding 35g of paraformaldehyde, controlling the temperature at 60-90 ℃, keeping the temperature for 6h, adding 60g of epoxy resin E44, stirring for 5h, adding 50g of polypropylene glycol diglycidyl ether, stirring for 5h, adding 250g of deionized water, uniformly stirring, finally cooling and discharging to obtain the clear, transparent and uniform water-soluble self-emulsifying phenol novolac modified amine waterborne epoxy hardener.

And (3) carrying out detection on various indexes of the waterborne epoxy curing agent product obtained in the embodiment 1-3, wherein the detection indexes comprise appearance, solid content, amine value and viscosity, and the detection results are shown in table 1.

TABLE 1 technical index test results of water-soluble self-emulsifying phenolic aldehyde modified amine waterborne epoxy hardener

Detecting the index	Example 1	Example 2	Example 3
				Type (B)	Water soluble type	Water soluble type	Water soluble type
Appearance of the product	Light yellow transparent liquid	Light yellow transparent liquid	Light yellow transparent liquid
				Viscosity (25 ℃, cps)	7000	6500	7200
Amine number (mg KOH/g)	130	140	148
				Solid content (%)	52	48	49

The aqueous epoxy curing agent products obtained in the examples 1-3 are reacted with E51 epoxy resin to prepare epoxy varnish, and various mechanical performance indexes are detected, wherein the mass ratio of the E51 epoxy resin to the aqueous epoxy curing agent is 100:130, the thickness of the prepared varnish is 28-32 mu m, the detection indexes comprise surface dryness, adhesion, positive and negative impact performance and bending resistance, and the detection results are shown in Table 2.

TABLE 2 results of mechanical Properties measurements of epoxy varnishes

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention disclosed herein are included in the scope of the present invention, and the scope of the present invention is subject to the scope of the claims.