| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for recovering and reusing specified raw materials (MEK, methanol, and calcium chloride) used for producing an MEK-modified resorcin/formalin resin, and to provide a method for controlling the concentration of calcium chloride in the MEK-modified resin to stabilize quality by improving a part of the production process. SOLUTION: A raw material resorcin, an aqueous solution of calcium chloride recovered, and a recovered MEK are added into a water solvent and stirred to form a two-phase system, and further a hydrochloric acid catalyst is added thereto, then, formalin is dropped in the reaction system to thereby advance a liquid-liquid heterogeneous reaction, and after the reaction, by an enclosed-system recycle production method including water washing and distillation, an aqueous solution of a resorcin/formalin resin having a calcium chloride concentration of 100 ppm or lower, a ratio of peak area corresponding to resorcin monomer to overall peak area of 3-9%, and a ratio of peak area corresponding to five or more resorcin nuclei to the above overall peak area of 30-55% is obtained. In the method for producing the MEK-modified resorcin/formalin resin, the recovery and reuse of the specified raw materials (methanol, calcium chloride, and MEK) are performed in parallel. COPYRIGHT: (C)2008,JPO&INPIT
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