New Reduction Method of Formaldehyde Emission from Wood-Based Materials

众所周知，胶合板和刨花板等木质材料在使用尿素甲醛树脂或三聚氰胺甲醛树脂粘合剂时会释放出甲醛。本研究的目的是开发新型甲醛清除剂及其有效利用方法。考察了三聚氰胺、尿素、一羟甲基三聚氰胺、硫酸氢钠和多肼类化合物作为脲醛树脂的甲醛清除剂。结果表明，聚肼类化合物包括低相对分子质量化合物和高相对分子质量化合物，特别是聚甲基丙烯酰肼和由异丁烯-马来酸酐共聚物合成的酰肼聚合物的有效性得到了肯定。比较了清除剂与胶粘剂混合、单板前处理和产品(胶合板)后处理3种处理方法。预处理法比混合法更有效，但不能完全限制锯切等加工过程中产生的新边缘的排放。在处理后的即刻和3个月内，用聚合型聚肼和清除剂对胶合板进行后处理是最有效的方法。

Wood-based materials such as plywood and particleboard have been known to liberate formaldehyde during utilization when they are manufactured by urea-formaldehyde resin or melamine-formaldehyde resin adhesives. This aim of this research was focused on developments of new formaldehyde scavengers and their effective utilization methods.Melamine, urea, monomethylolmelamine, sodium bisulfate and polyhydrazide compounds were examined as formaldehyde scavenger for urea-formaldehyde resins. As the results, effectiveness of polyhydrazide compounds including low and high molecular-weight compounds was recognized, especially both of poly (methyl metha-cryloyl hydrazide and hydrazide polymers obtained from the copolymer of isobutene-maleic anhydride). Three kinds of treatments ; mixing of scavengers with adhesives, pretreatment of veneers with scavengers and post-treatment of products (plywood) with scavengers, were compared. Pretreatment was more effective than mixing method, but could not restrict emissions completely from new edges produced by processing such as sawing. The post-treatment with polymer-type polyhydrazides of plywood with scavenger was found to be the most effective method just and three months after treatment.