Epoxy curing agent type and epoxy curing temperature

The epoxy resin curing agent is usually used when decorating the house, and the price is different. There are also many types of epoxy curing agents. What are the types of epoxy curing agents? The curing temperature of the epoxy resin is How much, let's let Xiaobian give you a detailed introduction!

First, what kind of epoxy curing agent

1. Aliphatic amines: The main varieties are ethylenediamine, diethylene (triene) triamines, and poly ethylene (support) polyamines. Its characteristic is that, curing at room temperature, curing speed, viscosity low temperature paint, easy to mix with other resins, easy to operate. The coating has high solvent resistance. However, the toxicity is large, heat is released when curing, and the service life is short. The curing is limited by the temperature and humidity conditions, and the paint film is whitened under the condition of high humidity. Produced orange peel, shrinkage and other ills, cured film heat resistance, mechanical strength is poor.

2. Aromatic amines: mainly meta-phenylenediamine, meta-xylylenediamine, etc. Its characteristic is that it needs to be cured under heating conditions, and it is inconvenient to mix with the resin, and the heat resistance and corrosion resistance of the cured product are more prominent. It is mainly used for heat curing process and can also be used as raw material for modified amine curing agent.

3, amine modified curing agent: The main addition of amine curing agent (such as 590,593 curing agent), T31 curing agent, phenolic amino alcohol curing agent. This mainly focuses on the toxicity problems of aliphatic amines and aromatic amines. It improves the original amine curing agent through addition reaction or condensation reaction. It is characterized by greatly reduced volatility and is called low-toxic or non-toxic curing agent. Customer service has the drawback of whitening without the induction period. However, the amount of curing agent increases, the amount can be changed within the scope of communication, and the range of the better dosage is determined through experiments. Due to the introduction of a new molecular structure in the amine-modified curing agent molecule, the coating process performance and the properties of the cured coating, such as the curing at low temperature and humidity, and the corrosion resistance and temperature resistance of the coating, have been changed to varying degrees. All can be improved.

Second, epoxy curing agent temperature

The curing temperatures of various curing agents are different, and the heat resistance of cured products is also very different. In general, a cured product having excellent heat resistance can be obtained using a curing agent having a high curing temperature. For addition polymerization type curing agents, the curing temperature and heat resistance increase in the following order: aliphatic polyamines

The heat resistance of the catalytic polyaddition curing agent is generally at the aromatic polyamine level. The heat resistance of anionic polymerization (tertiary amines and imidazole compounds) and cationic polymerization (BF3 complexes) is basically the same, which is mainly because the initial reaction mechanism is different, but ultimately it forms an ether-bonded network structure. .

The curing reaction is a chemical reaction, which is greatly influenced by the curing temperature. The temperature increases, the reaction speed increases, and the gel time becomes shorter. The logarithm of the gel time decreases with the increase of the curing temperature, but the curing temperature is too high. The properties of the cured product are degraded, so there is an upper limit of the curing temperature; the temperature at which the curing rate and the properties of the cured product are compromised must be selected as an appropriate curing temperature.

The curing agent can be divided into four categories according to the curing temperature: the curing temperature of the low-temperature curing agent is lower than room temperature; the curing temperature of the room-temperature curing agent is room temperature to 50°C; the curing temperature of the medium-temperature curing agent is 50 to 100°C; and the curing temperature of the high-temperature curing agent is 100°C or higher . There are few types of curing agents that are low-temperature curing type, such as polysterol type, polyisocyanate type, etc.; T-31 modified amines and YH-82 modified amines developed and put into operation in China can all be cured below 0°C. There are many types of room-temperature curing type: aliphatic polyamines, alicyclic polyamines, low-molecular polyamides, and modified aromatic amines. There are alicyclic polyamines, tertiary amines, carbazoles, boron trifluoride complexes, and the like which are moderate temperature curing types. Examples of high-temperature curing agents include aromatic polyamines, acid anhydrides, resole resins, amino resins, dicyandiamide, and hydrazide.

The above is a description of the type of epoxy curing agent and the curing temperature of the epoxy resin. After the introduction in the article, I believe that everyone knows about the type of epoxy curing agent and its temperature.