Abstract
The purpose of this study is to improve the flame-retardation of paper-base phenolic resin laminates without using halogen-or phosphor-containing flame retardants. Firstly, 2, 6-dimethylol-4-phenylphenol (DMPP) was synthesized from 4-phenylphenol and formaldehyde, then it was converted with benzoguanamine (BG) to a BG-modified phenolic resin (DMPP-BG). Structures and properties of DMPP and DMPP-BG were investigated with NMR, GPC and DSC. Secondly, DMPP-BG was blended with an ammonia resol in the DMPP-BG/resol ratio of 0/100-20/100 (wt/wt). The gelation time and curing temperature of DMPP-BG/resol blends (the DMPP-BG-modified phenolic resins) were almost the same as those of the resol itself. Paper-base DMPP-BG-modified phenolic resin laminates were prepared by compression molding, and gave superior results to the unmodified phenolic resin laminate in the flammability test by the UL94 vertical method : there was shown V-0 in the test results of the laminates from DMPP-BG/resol (?10/ 100) blends. The average burning rate of these laminates was about 1/10 times as low as those of the unmodified laminate. Also, the values indicating the performance of these laminates, such as oxygen index, electrical insulation and water resistance, were higher than those of the unmodified laminate.
