| 摘要 |
PURPOSE:The titled curing agent having excellent flow, scarcely undergoing separation and sediumentation and having good molding workability, prepared by mixing a boron compound, phosphoric acid, other acids, an emulsifier, and water at a specified mixing ratio. CONSTITUTION:A curing agent for phenolic resins is prepared by mixing 100pts.wt. boron compound, e.g., boric acid of particle diameter <= about 150mu, with 4-240pts.wt. inorganic acid other than phosphoric acid and/or aromatic sulfonic acid, e.g., sulfonic or phenolsulfonic acid, 4-300pts.wt. phosphoric acid, 0.1-15pts.wt. emulsifier, e.g., polyoxyethylene alkyl ether sulfonate salt, and 20- 150pts.wt. water. In use, the above curing agent is added in an amount of about 5-30wt%, based on a phenolic resin (preferably, resol type).
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