| 摘要 |
PURPOSE:To obtain in high productivity without degradation of the quality the titled resin of high conversion capable of giving laminates free from development of any bulge, by reaction of the raw materials for phenolic resin in a tank, and elimination of the resulting excessive water under reduced pressure followed by aging under specific condition. CONSTITUTION:A tank is charged with raw materials for phenolic resin such as phenol, formalin and catalyst(s), followed by heating with water vapor, etc. to raise the temperature within the tank, thereby refluxing the reaction mixture, thus proceeding with reaction. The resulting excessive water in the system is removed under reduced pressure followed by returning the tank to the state of ordinary pressure. Subsequently, in this state, an aging is carried out at temperatures higher than the final temperature in the above dehydration, and then cooling the tank as well as, normally, charging solvent, e.g. methanol, into the tank followed by agitation, thus obtaining the objective resin in the form of varnish.
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