An article to understand the curing technology of one-component epoxy adhesives

One-component glue is much more convenient to use than two-component glue, so it is often preferred

However, the preparation technology of one-component glue is much more difficult, not only to ensure reliable performance, but also to ensure long storage stability

For one-component epoxy glue, its core technology lies in its curing agent coating online coatingol.

According to the curing method, one-component epoxy adhesives can be divided into the following types: (1) room temperature moisture curing type; (2) thermal curing type; (3) cationic light curing type; (4) microcapsule type

Room temperature moisture curing

The curing agents used in this type of epoxy glue are mostly ketimine compounds.

In order to prolong the storage period of the glue, ketimine with a steric hindrance effect with a larger molecular volume on the side of the ketone group is often used to provide storage stability without reducing the curing speed

However, the way of moisture curing at room temperature is far from being able to meet the requirements of the automated assembly process for the curing speed

Heat curing type

Generally, it can be divided into medium temperature curing type and high temperature curing type.

This kind of glue uses heating-activated curing agent, which is relatively stable at room temperature and is insoluble in epoxy resin.

Commonly used latent curing agents include dicyandiamide, organic hydrazide, organic acid anhydride, imidazole, boron trifluoride-amine complex, etc.

Cationic light curing type

The curing agent of the cationic light-curing epoxy adhesive is a cationic photosensitive compound, that is, a photoinitiator.

Commonly used photosensitizers include aromatic diazonium salts, diaryliodonium salts, arylferrocene salts and triarylsulfonium salts

Microcapsule type

Some film-forming materials are used to encapsulate a component of the adhesive so that the glue can be stored stably

The capsule membrane of the microcapsule cannot react or miscible with the components, and the capsule membrane must have an appropriate thickness and strength to prevent unnecessary loss due to rupture during transportation

At present, the film-forming agents in microcapsule one-component epoxy adhesives include cellulose, gelatin, polyvinyl alcohol, polyester, polysulfone and so on

In general, one-component epoxy resin adhesives are easy to use, and the development of environmentally friendly one-component epoxy adhesives is still an inevitable trend in future development