How to effectively improve the compatibility between epoxy resin and curing agent?

Types, commonly used epoxy resin curing agents are aliphatic amines, aliphatic amines, aromatic amines, polyamides, anhydrides, resins, tertiary amines, and ultraviolet rays or light can also cure epoxy resin under the action of photoinitiators. Amine curing agents are generally used for normal temperature or low temperature curing, and acid anhydride and aromatic curing agents are commonly used for heating curing. Dosage, (1) amines are calculated as follows when amines are used as crosslinkers:

Amine dosage = mg hn, where: m = amine molecular weight, hn = number of active hydrogen, g = epoxy value (number of epoxy equivalents per 100 grams of epoxy resin). The range of change is not more than 10-20%, and if cured with excessive amine, the resin will become brittle.

If the dosage is too small, the curing will not be perfect. (2) When using anhydrides, calculate according to the following formula: the amount of anhydride = mg (where:

m = molecular weight of acid anhydride, g = epoxy value (for experiments....)

In order to improve the compatibility between epoxy resin and curing agent and improve the water resistance of the coating film, it is important to design both the epoxy resin and the curing agent in the form of dispersions. On the one hand, the hydrophilic group modification of epoxy resin, the early epoxy emulsion is prepared by the method of adding emulsifier, and its stability and water resistance are not good, and now most of them use polyethylene glycol, alcohol ether compounds or nonionic surfactants to modify the reaction with epoxy resin, and introduce hydrophilic groups into the epoxy resin molecule to make it have self-emulsifying properties. On the other hand, the curing agent can be modified as an addition of bisphenol A and amine, which is also modified with hydrophilic groups, and there is no free nonionic surface tranquil agent in the system, which is an aqueous dispersion or an oil-in-water emulsion, which can be used to reduce the viscosity of the system without phase separation.

At present, there are many patents for such aqueous dispersion curing agents in foreign countries, and some domestic manufacturers have launched such curing agent products.

And it has been applied in some areas. The system of water-based epoxy emulsion and water-based amine curing agent dispersion compound is called V-type water-based epoxy system, which changes the water-soluble state of amine curing agent in the past, and improves the matching with resin.

Generally speaking, there are two kinds of water-based coating curing agents, epoxy curing agent and isocyanate curing agent, both of which are used for curing at room temperature, and it must be no problem to meet the requirements you said.

According to your requirements, it may not be necessary to use a curing agent, but to use amino resin, long-term storage below 70°, and 150 half an hour of curing.

Compared with other types of adhesives, epoxy adhesives have the following advantages:

1) Epoxy resin contains a variety of polar groups and epoxy groups with great activity, so it has strong adhesion to metal, glass, cement, wood, plastic and other polar materials, especially materials with high surface activity, and the cohesion strength of epoxy cured products is also very large, so its adhesive strength is very high.

2) There is basically no low molecular weight volatiles produced during the curing of epoxy resin. The volume shrinkage of the adhesive layer is small, about 1% to 2%, which is one of the varieties with the smallest curing shrinkage among thermosetting resins. After adding filler, it can be reduced to less than 0 2%.

The coefficient of linear expansion of epoxy cured products is also very small. Therefore, the internal stress is small, and the influence on the bonding strength is small. In addition, the creep of the epoxy cured material is small, so the dimensional stability of the adhesive layer is good.

3) There are many varieties of epoxy resins, curing agents and modifiers, which can be designed through reasonable and ingenious formulations, so that the adhesives have the required manufacturability (such as rapid curing, room temperature curing, low temperature curing, water curing, low viscosity, high viscosity, etc.), and have the required performance (such as high temperature resistance, low temperature resistance, high strength, high flexibility, aging resistance, electrical conductivity, magnetic conductivity, thermal conductivity, etc.).

4) It has good compatibility and reactivity with a variety of organic substances (monomers, resins, rubber) and inorganic substances (such as fillers, etc.), and is easy to be modified by copolymerization, cross-linking, blending, filling, etc., so as to improve the performance of the adhesive line.

5) Good corrosion resistance and dielectric properties. It can resist the corrosion of acid, alkali, salt, solvent and other media. The volume resistivity is 1013-1016 ·cm, and the dielectric strength is 16-35kv mm.

6) General-purpose epoxy resin, curing agent and additives have many origins, large output, simple preparation, contact pressure molding, and large-scale application.

Epoxy resins have both secondary hydroxyl and epoxy groups, and the secondary hydroxyl group can react with isocyanates. Epoxy resin is directly added to the hydroxyl group of polyurethane adhesive as a polyol, and only the hydroxyl group participates in the reaction using this method, and the epoxy group fails to react.

Ordinary liquid epoxy resin appearance.

Ordinary liquid epoxy resin appearance.

The epoxy is opened with an acidic resin and a carboxyl group, and then reacts with the isocyanate in the polyurethane adhesive. Epoxy resin can also be dissolved in ethyl acetate, phosphoric acid is added to the heating reaction, and its adduct is added to the polyurethane adhesive; the initial adhesion of the glue; Heat resistance and hydrolytic stability can be improved, and alcohol amines or amines can be reacted to form polyols, and the presence of tertiary nitrogen atoms in the adducts can accelerate the NCO reaction.

The use of epoxy resin as a polyhydroxy component combines the advantages of polyurethane and epoxy resin, and has good adhesion strength and chemical resistance, and the epoxy resin used in the manufacture of polyurethane adhesive generally uses EP-12, EP-13, EP-16 and EP-20 varieties.

<> epoxy resin curing agent is made of phenol, formaldehyde, ethylenediamine, p-tert-butylphenol, n-butanol glycidyl ether, polypropylene glycidyl ether and other raw materials. Commonly used epoxy resin curing agents are aliphatic amines, aliphatic cyclic amines, aromatic amines, polyamides, anhydrides, resins, tertiary amines, general ultraviolet rays or light can make epoxy resin cure, epoxy resin curing basically does not produce low molecular volatiles, so it can be low-pressure molding or contact pressure molding.

1. Curing agent formula epoxy resin

1. Epoxy resin curing agent formula: phenol, formaldehyde, ethylenediamine, p-tert-butylphenol, n-butanol glycidyl ether, polypropylene glycidyl ether. Epoxy resin curing agent is mainly used in the field of adhesive material technology, which has low temperature resistance, waterproof and other special conditions.

2. The commonly used epoxy resin curing agents are aliphatic amines, aliphatic cyclic amines, aromatic amines, polyamides, anhydrides, resins, tertiary amines, and ultraviolet and light can cure epoxy resin. If normal temperature or low temperature curing is required, amine curing agents can be used, and acid anhydride and aromatic curing agents can be used for heating curing.

3. Epoxy resin will not produce low molecular volatiles when curing, so it can be molded under low pressure or contact pressing. In addition, it can be combined with various curing agents to create solvent-free, high-solids, powder coatings and water-based coatings and other environmentally friendly coatings.

Second, the role and use of epoxy resin

1. Use: As a coating, epoxy resin is used in coatings, and it can be made into varieties with different characteristics and uses. Function: It has good chemical resistance, especially alkali resistance, good heat resistance and electrical insulation, and good color retention of paint film.

2. Epoxy resin refers to the general term of polymers containing more than two epoxy groups in the molecule, which is the product of epichlorohydrin and bisphenol A or polyol. Because the epoxy group has a certain chemical activity, it can be used with a variety of active hydrogen compounds to open the ring, solidify and cross-link to form a network structure, so it is a thermosetting resin.

3. There are many feres of epoxy resin, if classified according to professional use, it can be divided into mechanical epoxy resin adhesive, construction epoxy resin adhesive, electronic epoxy resin adhesive, repair epoxy resin adhesive, traffic adhesive, marine adhesive, etc.

Generally, epoxy resin E 51: The curing agent is 100:50, but some of the curing agents are 100:

40, there are also lower or higher. For example, 100:20 or 100:

60。Normally, it is desirable to have as low a curing agent ratio as possible, because the cost is lower (because the curing agent is expensive).

Amine dosage = mg hn.

m = amine molecular weight.

hn = number of active hydrogen.

g = epoxy value (number of epoxy equivalents contained in 100 grams of epoxy resin).

When using anhydrides, it is calculated as follows:

Acid anhydride dosage = mg (where:

m = anhydride molecular weight.

g = epoxy value (is the experimental coefficient.)

What is the problem? Headless and brainless.

Do you want to ask about market capacity, market share, or a ratio of production?

Amine dosage = mg hn.

where: m = amine molecular weight.

hn = number of active hydrogen.

g = epoxy value (the number of epoxy equivalents contained in 100 grams of epoxy resin) is calculated as follows when using anhydrides:

Acid anhydride dosage = mg (where:

m = anhydride molecular weight.

g = epoxy value (is the experimental coefficient.)

The reinforcing agent can cure the agent, that is, it can be done, and the resin is a liquid without a curing agent, and it will not dry when applied to the ground. According to the manufacturer's production formula, the dosage of curing agent is also different.

Suzhou Meiguowang Floor Material**** Water-based epoxy curing agent, water-based epoxy floor paint 1 The water-based epoxy floor made by water-based epoxy curing agent is lower than the ordinary cost, and the quality is still the same.

2. Water-based is also green and environmentally friendly, and it is very healthy for both people and the environment.

3 Water-based is also suitable for wet ground. It is also a trend of development.

The curing process of epoxy materials is a very complex process of physical and chemical change, and there are many influencing factors. It can be summarized as follows:

1) Wetting and impregnation of solid materials (fibers, fillers, bonded surfaces, coating substrates, etc.) by epoxy adhesive solution (liquid epoxy resin glue, or epoxy resin solution, or epoxy resin melt). It can also be made into prepregs or molding compounds. The main influencing factors are the compatibility of the glue with the solid material (affinity, which can be improved by adjusting the glue formulation design and solid surface treatment) and the viscosity of the glue (depending on the glue formulation and ambient temperature).

2) The material fills the mold cavity or leveling to form a dense object. The main influencing factor is the fluidity of the material, mainly the viscosity of the glue. It all depends on the glue formulation and the ambient temperature. Pressurization and vacuuming can be used to assist in mold filling and the formation of dense objects.

3) Carry out the curing reaction. Under certain conditions, epoxy oligomers begin to react with curing agents and modifiers, and solidify three-dimensional cross-linked structures from glue gelation to vitrification. The main influencing factor is the thermal history of the system.

Including: preheating temperature, ramp-up rate, curing temperature, curing time, post-curing temperature and time, etc. In addition, the curing pressure also plays a certain role in the curing reaction and the compactness and shape stability of the product.

The main influencing factors are glue formulation and ambient temperature and humidity.

4) Structure formation of epoxy matrix (epoxy cure). This is formed gradually as the curing reaction of the epoxy resin progresses. It includes the formation of the chemical structure of the solidified matter and the formation of the aggregate structure of the solidified matter. The main influencing factor is the thermal history of the glue formulation and system.

5) Formation of interfacial layer structure of epoxy materials. It is also gradually formed as the curing reaction of epoxy resin progresses. It depends not only on the glue formulation and the thermal history of the system, but also on the surface properties of materials such as fibers and fillers.

Epoxy resin is an organic polymer compound that contains two or more epoxy groups in the molecule, and their relative molecular weight is not high except for a few. The molecular structure of epoxy resin is characterized by the presence of active epoxy groups in the molecular chain, which can be located at the end, middle or in a cyclic structure of the molecular chain. Because the molecular structure contains active epoxy groups, they can cross-link with various types of curing agents to form insoluble, non-meltable polymers with a three-way network structure.

All polymer compounds containing epoxy groups in the molecular structure are collectively referred to as [epoxy resin mortar flooring].

Epoxy resin mortar flooring.

for epoxy resin. The cured epoxy resin has good physical and chemical properties, it has excellent bonding strength on the surface of metal and non-metallic materials, good dielectric properties, small variable shrinkage, good dimensional stability of products, high hardness, good flexibility, and stability to alkali and most solvents, so it is widely used in national defense, national economic departments, for pouring, impregnation, laminating materials, adhesives, coatings and other purposes.