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IPEMA: the reactive diluent for more durable hard coatings.
Hard coatings are challenging products to produce and to sustain.
Reactive diluents are used to ease the manufacturing process of hard coating solutions by reducing the viscosity of the main agent. The hard coating is then formed by cross-linking and generally UV curing is used. For hard coating solutions with low viscosity the process tends to be inhibited by oxygen leading to either half cured sticky products or energy and time loss. Other issues such as curling or surface cracks may occur when curing hard coatings. Indeed if a hard coating is formed in a one-step cross-linking, the upper layer will shrink and the base layer, curl. Those layer defaults will then affect the coating’s properties and durability.
IPEMA is a transparent liquid with low viscosity and two double bonds with different reactivity. IPEMA is easy to use and can help achieve both fast curing and improved durability. IPEMA works as a UV curing accelerator and thanks to its structure, cross-linking occurs step wisely. Therefore when the main agent is mixed with IPEMA not only the curing is quicker but because of the stepwise cross-linking, the curling and surface cracking are prevented.
Another challenge is the durability of hard coatings which become brittle after a while because of a lack of balance between hardness and flexibility. Here again, because of the stepwise crosslinking, IPEMA can enable flexibility and hardness to co-exist in a same product. It has been proven that hard coatings made with IPEMA have higher elongation and scratch resistance than those made with other reactive diluents such as HDDA.
Kuraray’s IPEMA is a one-product solution to many challenges hard coating formulators are facing. Now, you know what to expect when using IPEMA as a co-monomer in your resins.
