Description

Epoxy diluents are mainly used to reduce the viscosity of the epoxy adhesive system, dissolve and disperse and dilute the adhesive, and improve the coating and fluidity of the adhesive. Epoxy diluents also play a role in extending the service life. There are many ways to classify the diluent, according to its use mechanism, it can be divided into two categories of inactive diluent and active diluent.

Inactive diluents

Inactive diluents do not contain active groups in their molecules and are mostly inert solvents. They do not react with epoxy resins, hardeners, etc. Inactive diluents are purely physically mixed into the resin. In addition to playing a diluting role, it has an impact on mechanical properties, heat distortion temperature, media resistance and aging damage. In the choice of inactive diluent should consider the solvent evaporation rate, if the evaporation rate is too fast, the surface of the adhesive layer is easy to form a film, preventing the adhesive layer of solvent inside the escape, resulting in bubbles in the adhesive layer. If the evaporation rate is too slow, the solvent remains in the adhesive layer, which will affect the strength of the bond. Usually, several solvents with different boiling points are mixed to regulate the evaporation rate. It is mostly used in rubber adhesive, phenolic adhesive, polyester adhesive and epoxy adhesive.

Reactive diluents

Reactive diluents are generally low molecular compounds with one or two or more epoxy groups. They can be directly involved in the epoxy resin curing reaction, become part of the epoxy resin curing material crosslinking network structure. Reactive diluents have almost no effect on the properties of the cured product and can sometimes increase the toughness of the curing system. Active diluent is divided into monofunctional active diluent and difunctional active diluent.

Active diluents are generally toxic and must be used with safety in mind. Prolonged contact will often cause skin irritation and in severe cases, even ulcers. Monofunctional active diluent dilution effect is better, aliphatic type has better dilution effect than aromatic type. The acid and alkali resistance of the curing products using aromatic active diluents does not change much, but the solvent resistance is reduced. The use of monofunctional reactive diluents will reduce the heat distortion temperature, which is due to its use will make the cured product crosslinking density decreased. Flexural strength and impact toughness are improved with long carbon chain active diluents. When used in small quantities, it has no effect on the hardness of the cured product, while the coefficient of thermal expansion increases.

Diluent selection principle

• Try to use active diluents, to improve the processability and at the same time improve its adhesive and mechanical properties.
• Choose those diluents that are similar to the chemical structure of the main resin. They will participate in the reaction with the main resin in the presence of other additives, and greatly improve the performance of the adhesive layer.
• Select low volatility, small odor and as low as possible toxicity varieties, to reduce the harm of using active diluent on the human body. Because most of the active or inactive diluents have odor and low toxicity.
• Should choose the source of easy, non-flammable and non-explosive, low-priced active diluent.
• Should be through the theory and experiments to choose the most appropriate amount to add.

We Nanjing Yolatech can provide a variety of high purity low chlorine epoxy resin active diluents, widely used in insulation materials, electronic potting, electrical casting and other fields, including 1,4-Butanediol diglycidyl ether(YLD-6018),1,6-Hexanediol diglycidyl ether (YLD-6008), Neopentyl glycol diglycidyl ether(YLD-6009), Neodecanoic acid glycidyl ester(YLD-8001) and so on.

Welcome new and old customers to consult at any time!