| 摘要 |
PURPOSE:The reaction between a phenol and formaldehyde is carried out in an aqueous medium, the condensation is effected, as the unreacting components are vaporized, then, the vaporized components are removed to give the titled liquid composition with low viscosity and reduced phenol content. CONSTITUTION:The reaction of a phenol with formaldehyde is conducted in an aqueous medium in the presence of a catalyst such as lead naphthenate-zinc oxide to form a precondensate. Then, the product is passed through a long jacketed tube heated with steam to vaporize water and unreacting monomers. In the meantime, the precondensate undergoes liquid-phase condensation reaction and is introduced into a reduced-pressure atmosphere to remove the vaporized components out of the system to obtain the objective composition having benzyl ether linkage, methylol groups, and methylene bonds. USE:The product is used as a component for urethane reaction.
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