Synthetic process of phenolic resin

Abstract

The invention discloses a synthetic process of phenolic resin in the technical field of fine chemical synthesis. The synthetic process comprises the following steps: sequentially adding raw materialsincluding phenol, formaldehyde, oxalic acid and MIBK into a reaction kettle; starting to raise the temperature to 100 DEG C; closing the reaction kettle and emptying; starting to adjust the pressure in the kettle to 110kpa-120kpa; opening steam of the reaction kettle to keep reflux in the kettle; starting to time for 2-5 hours; after the reflux is finished, starting to recycle phenol and MIBK; keeping the reaction kettle to continuously raise the temperature to 160 DEG C and keeping the vacuum degree to be below 5kpa; and after the recycling is finished, sampling and detecting. According to the synthetic process disclosed by the invention, quantitative MIBK is added and then the temperature is raised; certain pressure is kept and reaction is carried out under micro-positive pressure; in the phenolic resin produced by the manner, the synthetic efficiency is higher and the molecular weight distribution of the obtained phenolic resin is more uniform and more reasonable; the requirements on gelation time of phosphorus-containing epoxy industry are met; and the positive pressure reaction is adopted and air is isolated, so that the color and luster are lighter.

Description

technical field [0001] The invention relates to the technical field of fine chemical synthesis, in particular to a synthesis process of phenolic resin. Background technique [0002] Phenolic resin is a large class of synthetic resins obtained by polycondensation of phenolic compounds and aldehyde compounds. The phenolic compound used is mainly phenol, other cresols, bisphenol A or a mixture of several phenols can also be used, and the aldehyde compounds used are mainly formaldehyde, paraformaldehyde, furfural, acetaldehyde and the like. The phenolic resins produced are divided into thermoplastic phenolic resins (using acidic medium as catalyst) and thermosetting phenolic resins (using alkaline medium as catalyst) according to their functionality, molar ratio of phenol and aldehyde, and synthetic catalysts. [0003] Thermoplastic phenolic resin has good acid resistance, alkali resistance, heat resistance and electrical insulation after curing. It is widely used in many aspec...

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Problems solved by technology

[0004] At present, the synthesis process of thermoplastic phenolic resin (using phenol and formaldehyde as raw materials) is briefly described as follows: phenol, formaldehyde and a certain amount of water are put into the reactor, and oxalic acid is selected as the catalyst. After heating up, reflux, standing still, cutting water and recovering phenol, the finished product of phenolic resin is obtained, and then epoxidized with excess epichlorohydrin to obtain novolac epoxy resin, but such a synthesis process has low synthesis efficiency and obtains The molecular weight distribution of the phenolic resin is not very uniform, and the color is not light enough

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