In the production of epoxy boards, we all use curing ag […]
In the production of epoxy boards, we all use curing agents to quickly cure the epoxy boards. The requirements for epoxy boards are different in different situations. This is also the gel time of epoxy boards at different temperatures. It doesn't matter, what is the heat resistance of epoxy boards under different temperature curing agents?
The difference of epoxy board under different stable curing agents is still very different;
It is common that the higher the temperature of the curing agent accompanied by the temperature, the longer the gel time of the epoxy board.
The higher the temperature of the epoxy board, the higher the curing agent temperature, it will also cause uneven heating during the curing process of the epoxy board, which will cause the cross-density distribution of the cured epoxy resin to be not very good, and also make the epoxy board resin cured The performance of things has declined. Correspondingly, we should determine what kind of curing agent we use according to the needs of the product itself. Here, we can refer to the heat resistance combination of epoxy board mentioned below to determine our product.
Curing agent type of curing temperature
There are about four types of curing agent temperatures at different curing temperatures.
① Low temperature curing agent that can be cured at room temperature; ② Room temperature curing agent that cures at room temperature to 50 ℃; ③ Medium temperature curing agent of 50 to 100 ℃; ④ High temperature curing agent of more than 100 ℃.
The curing agent usually used is a room temperature curing agent; there are few types of curing agents in the low temperature curing agent type, and there are only two curing agents: isocyanate and polythiol. There are many types of room temperature curing agents, such as aliphatic polyamines, alicyclic polyamines, low molecular weight polyamides, and modified aromatic amines. Among the moderate temperature curing agents are alicyclic polyamines, tertiary amines, imidazoles and boron trifluoride complexes. Epoxy boards are high-temperature curing agents such as aromatic amines, acid anhydrides, resols, amino resins, dicyandiamide, and hydrazides. As an epoxy board manufacturer, we still need to understand these curing agents.
The heat resistance of products that use high-temperature curing agents is better. After all, they are cured at high temperatures. However, such high-temperature curing epoxy boards are cured at a lower temperature first, and then wait for the epoxy board to reach In the pre-cured gel state, the product is cured by high-temperature heating.
The difference in heat resistance of epoxy board
At different curing agent temperatures, the heat resistance of our epoxy board cured products is also different. For the heat resistance of epoxy resin boards, we can compare the curing agent products according to the following.
The heat resistance of aliphatic polyamine<alicyclic polyamine<aromatic polyamine~phenolic resin<anhydride catalyzed addition polymerization curing agent is generally at the level of aromatic polyamine.
The heat resistance of anionic polymerization type (tertiary amine and imidazole compounds) and cationic polymerization type (BFa complex) curing agent is basically the same, although the reaction mechanism is different from bisphenol A epoxy resin, but finally Both form a three-dimensional network structure of ether bonds.