Low profile additives for crosslinkable resins

摘要

Shrinkage of cured resins is reduced by mixing the crosslinkable resin with a low profile additive (LPA). The LPA is in the form of particles which comprise an SCC polymer (or a similar crystalline polymer which melts over a narrow temperature range). The system is cured at a temperature above the melting point of the crystalline polymer (Tp), and the system and the LPA are such that at least part of the LPA remains as a separate phase in the curable resin at temperatures below Tp. It is believed that at least part of the crystalline polymer remains as a separate phase in the resin as it cures. Preferably at least part of the crystalline polymer forms a separate phase in the cured polymer after it has cooled.