Hybrid curing

In comparison with cationic curing systems, hybrid curing systems increase the rate of cure, produce cured films with improved solvent resistance, and offer a greater formulation latitude. When compared to free radical cure, better... 

Initiation of UV Hybrid Curing Kinetics of Photoinitiated Reactions... 

Recently, Endo and coworkers have developed novel sulfonium type initiators that can initiate polymerization either upon irradiation or upon thermal treatment. In addition, these photoinitiators are shown to be functional for both cationic and radical polymerizations. This dual activity is particularly important in hybrid curing systems for coatings and adhesions [28]. Scheme 11.6 contains the general steps for the synthesis of these photoinitiators from sulfides. 

Another mode of dual curing involves the simultaneous occurrence of free radical and cationic radiation-induced cross-linking polymerization of formulations containing appropriate initiators [20, 23, 28]. This method, which is called hybrid curing, leads to coatings with imique properties. A typical hybrid-cure system contains a diacrylate and a diepoxide, the former polymerizing by a free radical and the latter by a cationic mechanism. Exposure of the system to in-... 

S. Peeters, Overview of Dual-Cure and Hybrid-Cure Systems in Radiation Curing, Chapter 6 in Vol. Ill of [7j. 

Features Acrylate, anhydride and carboxyl functionality good cure speed, exc. copper adhesion, good solv. and acid resist., exc. aq. development hybrid cure systems high acid no. for alkali strippability Properties APFIA 50-150 clear liq. sp.gr. 1.11-1.15 dens. 9.3-9.6 Ib/gal vise. 10,000-25,000 cps acid no. 130-160 flash pt. (PMCC) 115-120 F 70 2% resin content... 

Features Good cure speed, exc. copper adhesion, good solv. and acid resist., exc. aq. development hybrid cure systems high acid no. for alkali strippability... 

Ultramid B3 Ultramld B4 oligomer, hybrid cure systems... 

Peeters, S., Overview of dual-cure and hybrid cure systems in Radiation Curing in Polymer Science and Technology, Vol. 3. Fouassier, J.P. and Rabek, J.F. (Eds.) (pp. 177-217), Chapman and Hall, Andover, 1993. 

The formation of IPNs combining the properties of the two polymer backbones can be achieved using the hybrid cure technique where a blend of a radical and a cationic monomer/oligomer is photopolymerized. The consecutive two-step irradiation procedure is the most common two Pis... 

The final structure and morphology of hybrids cured at a high temperature were characterized using SAXS and electron microscopy (SEM). 

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