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Abstract

A process for producing a modified phenolic resin, comprising heating a heavy oil or pitch of given average molecular weight and, per mol, calculated from the average molecular weight, of the heavy oil or pitch; 0.3 to 25 mol, in terms of formaldehyde, a formaldehyde compound and 0.5 to 50 mol of a phenol of the formula (I) (wherein R.sup.1 represents a linear or branched unsaturated hydrocarbon group having 1 to 2 unsaturated bonds and having 2 to 10 carbon atoms, p is 1 or 2, X represents an alkyl group having 1 to 5 carbon atoms, and q is 0 or 1) under stirring in the presence of an acid catalyst to thereby effect a polycondensation. The modified phenolic resin obtained by this process, as compared with the conventional modified phenolic resin produced from a heavy oil or pitch as a feedstock, has an extremely low softening point so as to be flowable at about room temperature and has also a low melt viscosity, thereby ensuring very excellent moldability. Further, in combination with an epoxy resin, the modified phenolic resin can be formed into a molded article which is excellent in not only heat resistance, moisture resistance, corrosion resistance and adhesive force but also mechanical properties such as dimensional stability and strength.

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