(JP6128183-A)      The prepn. comprises (i) reacting phenol with formaldehyde in the presence of an acid catalyst and removing catalyst, water and unreacted phenol from the obtd. mixt. to obtain a crude bisphenol F; and (ii) distilling the crude prod. to obtain a highly pure bisphenol F as a distillate, having a binuclear moiety-content of at least 95 wt.% and a novolak phenol resin, as a still-bottom prod. having a binuclear moiety-content of not more than 15% by area.    A general use bisphenol F is pref. prepd. simultaneously by opt. additionally admixing the highly pure bisphenol F with the remaining crude bisphenol F.    A high mol. wt. novolak phenol resin is pref. prepd. simultaneously by opt. additionally polymerising the novolak phenol resin with formaldehyde in the presence of an acid catalyst.    The phenol and formaldehyde are reacted in pref. molar ratio (P/F) of 6-30.    The distn. is pref. continuously in a still maintained at 1-5 mm Hg and 220-250 deg. C by continuously feeding crude bisphenol F to the still, condensing part of the gases generated in the still, returning the condensate to the still and withdrawing still bottom prod.    The distn. appts. opt. comprises stills.    The condenser comprises a multi-tubular cylindrical or a coil- heat exchanger.    The partial condensn. wt. ratio range is 0.05-0.5.    USE -   The bisphenol F is used as a starting material for epoxy and polycarbonate resins. Novolak phenol resins are useful as resistance materials, binders for mould prodn., hardeners for epoxy resins and are widely used in electronic material    (US5395915-A)      Simultaneous prepn. of pure bisphenol-F and a high mol. wt. novolak phenol resin comprises: (1) reacting phenol with formaldehyde in the presence of an acid catalyst and removing the catalyst, water and unreacted phenol from the resulting prod. to give crude bisphenol-F; (2) continuously distilling a part of the crude bisphenol-F in a still at 1-5 mmHg while continuously withdrawing a still bottom prod. to give a high purity bisphenol-F as a distillate with binuclear moiety-content of not less than 95 wt.% and a novolak phenol resin, as a still bottom prod. with a binuclear moiety content of not more than 15% by area; and (3) polymerising the novolak phenol resin with formaldehyde in the presence of acid catalyst.    ADVANTAGE -   High purity bisphenol-F is produced.