New Curing System of Urea-Formaldehyde Resins Under Neutral Condition

新型脲醛树脂中性条件固化体系

• 批准号: 61560184
• 负责人: TOMITA Bunichiro
• 金额: $ 1.47万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61560184/
• 关键词: Urea-Formaldehyde Resin; Polyhydrazide; Neutral curing; Formaldehyde emission; ユリア・メラミン共縮合樹脂

The conventional curing system of UF resins is accomplished in the strong acidic state. The difficulties of the resins are considered to be caused from the residual strong acid, which will accelerate the hydrolysis of the final products. From this point of view, the development of the new curing system using neutral condition was investigated in the present report. The new curing system is based on the simple method to mix UF resins with polyfunctional hydrazide compounds under around neutral conditions. Results were concluded as follows:1. The adhesive strengths of the plywood made using four kinds of dihydrazide compounds as hardner of commercial UF resins were not al all inferior to the conventional curing by ammonium chloride both in the normal test and the soaking at 60 ゜C and passed the JAS value.2. The curing system using dihydrazide polymers as hardner not only showed comparable adhesive shear strengths with the conventional curing of UF resins, but also reduced the formaldehyde emission from the final product of plywood.3. It was concluded that the reaction of hydrazide compounds with UF resins involves two stages. The first stage is the reaction of hydrazide group with free formaldehyde. The second stage at the rather higher temperature is due to the cocondensation of hydrazide groups with methylol group of UF resins to give the crosslinking networks between UF resins and hydrazide compound.From the practical point of view, the new curing system has the great advantage of reducing the formaldehyde emission from the final products using urea-formaldehyde resins and to cure UF resins under the neutral condition.

脲醛树脂的常规固化体系是在强酸状态下完成的。树脂的困难被认为是由于残留的强酸，这将加速最终产品的水解。从这个角度出发，本报告研究了使用中性条件的新固化体系的开发。新的固化体系是基于在中性条件下将脲醛树脂与多官能酰肼化合物混合的简单方法。研究结果如下：1.用四种二酰肼类化合物作为脲醛树脂固化剂所制得的胶合板，无论是在常规试验中，还是在60 ℃的浸泡试验中，胶合强度均不低于常规氯化铵固化胶合板，并通过了JAS值.以二酰肼类聚合物为固化剂的固化体系不仅具有与常规固化脲醛树脂相当的粘接剪切强度，而且还降低了最终产品的甲醛释放量.结果表明，酰肼类化合物与脲醛树脂的反应分为两个阶段。第一阶段是酰肼基与游离甲醛的反应。第二阶段是脲醛树脂中的酰肼基团与羟甲基发生共缩合反应，形成脲醛树脂与酰肼化合物之间的交联网络，从实用角度看，新的固化体系在降低脲醛树脂最终产品的甲醛释放量和在中性条件下固化脲醛树脂方面具有很大的优势。

项目成果

富田文一郎: 日本木材学会誌.

富田文一郎：日本木材学会杂志。

Katsumasa Miake, Bunichiro Tomita: "Development of New Curing System of Urea-Formaldehyde Resins Under Neutral Condition" Mokuzai Gakkaishi.

Katsumasa Miake、Bunichiro Tomita：“中性条件下脲醛树脂新型固化体系的开发”Mokuzai Gakkaishi。