FIELD: chemistry.
SUBSTANCE: invention relates to a method of producing ortho-cresol novolac epoxy resin and a polymer composition for sealing semiconductor devices which contains said resin. The method of producing ortho-cresol novolac epoxy resin involves polycondensation of ortho-cresol and formaldehyde in equimolar ratio while heating in the presence of an acid catalyst in the medium of n-butanol, reaction of the obtained product with excess epichlorohydrin while heating in the presence of an alkaline catalyst, distillation of epichlorohydrin and extracting the end product. Formaldehyde is used in form of para-formaldehyde. Polycondensation of ortho-cresol and para-formaldehyde is carried out at 115±2°C, first in the presence of 6-8 pts.wt oxalic acid until achieving 35-45% conversion, and then in the presence of 3-5 pts.wt pair-toluene sulphonic acid until complete extraction of the calculated amount of water, n-butanol is then distilled, the reaction mass is neutralised, after which 350-400 pts.wt epichlorohydrin is added and then crushed sodium hydroxide in portions for 1.5-2.0 hours while maintaining temperature in the range of 65-70°C, subsequently holding the reaction mass for 1.0-2.0 hours, distillation of excess epichlorohydrin and n-butanol, washing the resin with chloroform and water and extracting the end product from the chloroform solution by distilling off the chloroform. The polymer composition for sealing semiconductor devices contains ortho-cresol novolac epoxy resin as binder, phenol novolac resin as hardener, quartz filler, glycidyl oxypropyl trimethoxysilane as a finishing agent, triphenyl phosphine as an accelerator, wax and soot.
EFFECT: method of obtaining o-cresol novolac epoxy resin, suitable for producing composite material which can be used in a high vacuum at 105±5°C, with heat resistance of not lower than 160°C and chemical resistance in hot amide solvents.
3 cl, 2 tbl
