Novel high performance materials. Calixarene derivatives containing protective groups and polymerizable groups for photolithography, and calixarene derivatives containing active ester groups for thermal curing of epoxy resins

Abstract

This paper reviews our recent studies on the syntheses and functions of novel calixarene derivatives with excellent thermal stability as high performance materials. Calixarene derivatives containing protective groups such as tert-butoxycarbonyl (t-Boc), trimethylsilyl (TMS), and cyclohexenyl (CHE) groups were successfully prepared by the reaction of certain calixarenes, p-methylcalix[6]arene (1a), p-tert-butylcalix[8]arene (1c), and C-methylcalix[4]resorcinarene (Id) with the corresponding protecting reagents. Calixarene containing radically polymerizable groups such as methacryloyl groups and cationic polymerizable groups such as propargyl, vinyl ether groups were prepared in good yields. Calixarene derivatives containing cyclic ethers such as oxirane, oxetane, and spiro orthoesters were also prepared. Calixarene derivatives thus obtained had good film forming property and thermal stability. It was proved that the photoinduced deprotection of the calixarene derivatives containing protective groups in the presence of a photo-acid generator proceeded easily to give the corresponding calixarenes with phenol groups. Photoinitiated polymerization of the calixarenes with various polymerizable groups using suitable photoinitiators in the film state proceeded efficiently to produce crosslinked films. Furthermore, thermal curing of epoxy resins with calixarenes (1a. 1c, 1d), and calixarenes containing active ester groups using certain catalysts were studied to found that the calixarenes were useful curing agents for epoxy resins.