PREPARATION OF BINDERS FROM INEXPENSIVE B Y-PRODUCTS FOR USE IN HIGH-PRESSURE PHENOLIC LAMINATES .1. LABORATORY PREPARATION OF PHENOSOLVAN PITCH RESOLS AND THE MANUFACTURE AND TESTING OF 10-PLY LAMINATES

Caustic and ammonia catalyzed resols from phenosolvan pitch and formal dehyde were formulated as laminating resins for impregnation of Kraft paper. Ten-ply Kraft paper laminates were produced and tested for stre ngth as to quantify the performance of pitch resols prepared with diff erent catalysts and formaldehyde additions during pre-polymer formatio n. A complete description of the experimental set up for the manufactu re of the resins and laminates will be given, since it formed the foun dation for further research in this series of articles involving pheno solvan pitch as one of the components in the development of an inexpen sive binder system for laminated materials. As a whole pitch resols as sole binder systems produced insufficient physical properties. The ca ustic catalyzed resols performed better at higher formaldehyde additio ns, while ammonia resols were less dependant on formaldehyde additions and formed somewhat stiffer systems. The deficiencies of caustic pitc h resol were partly alleviated by mixing with phenol reset impregnatin g varnish, resulting in high strength and modulus of laminates with mo derate toughness.