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一、前言常温固化树脂砂是六十年代发展起来的新工艺,到七十年代发展较快。北京铸铁件用常温固化树脂系列,即BZF型,按含糠醇量不同,分为BZF——65,BZF——70,BZF——75三种产品,在完成一系列工艺和工作性能实验基础上,投入几个不同类型的工厂进行试验性生产,取得了良好效果。二、BZF脂树 (一)合成机理一般认为,糠醇改性尿醛树脂制备中的化学反应分两步进行,首先是甲醛与尿素聚合生成二羟甲尿,其化学反应如下:
I. Introduction Room temperature curing resin sand is developed in the sixties new technology, to the seventies faster development. Beijing cast iron used at room temperature curing resin series, namely BZF type, according to the different amount of furfuryl alcohol, divided into BZF - 65, BZF - 70, BZF - 75 three products, completed a series of experimental process and performance basis , Put into several different types of factories for experimental production, and achieved good results. Second, BZF lipid tree (a) the synthesis mechanism It is generally believed that furfuryl alcohol modified urea-formaldehyde resin preparation chemical reaction in two steps, the first is the polymerization of formaldehyde and urea to produce dimethylolurea, the chemical reaction is as follows: