| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a novolak type phenol resin having a low content of unreacted phenols and a narrow molecular weight distribution. SOLUTION: This method for producing the novolak type phenol resin is carried out by reacting a methylol compound of phenols with phenols using phosphoric acids as a catalyst. The phosphoric acids in an amount of≥0.2 mol based on 1 mol of the phenols are preferably used and the phosphoric acids are preferably phosphoric acid. The resultant novolak type phenol resin preferably has≤5 wt.% content of the unreacted phenols and the dispersity of the molecular weight distribution is preferably 1.1-2.0. COPYRIGHT: (C)2005,JPO&NCIPI
|
