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 R1 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.
一种生产改性
酚醛
树脂的工艺,包括加热给定平均分子量的重油或
沥青,以平均分子量计算,每摩尔重油或
沥青;0.3至25摩尔(以
甲醛计)
甲醛化合物和0.在酸催化剂的存在下,在搅拌下加入 0.5 至 50 摩尔的式 (I)
苯酚(其中 R1 代表具有 1 至 2 个不饱和键且具有 2 至 10 个碳原子的线性或支链不饱和烃基,p 为 1 或 2,X 代表具有 1 至 5 个碳原子的烷基,q 为 0 或 1),从而实现缩聚。
与传统的以重油或
沥青为原料生产的改性
酚醛
树脂相比,通过该工艺获得的改性
酚醛
树脂具有极低的软化点,因此在室温下即可流动,同时还具有较低的熔体粘度,从而确保了极佳的成型性。此外,将改性
酚醛
树脂与环氧
树脂结合使用,还可制成模塑制品,这种制品不仅具有优异的耐热性、防潮性、耐腐蚀性和粘合力,而且还具有优异的机械性能,如尺寸稳定性和强度。