改性聚乙烯醇甲醛胶粘剂的研制

Development of modified polyvinyl formal adhesives

介绍了以聚乙烯醇、甲醛、淀粉等为主要原料制备聚乙烯醇缩甲醛胶粘剂的工艺。探讨了甲醛、淀粉、尿素和改性剂的用量、pH值、反应温度等因素对聚乙烯醇缩甲醛胶粘剂的制备与性能的影响。实验结果表明,制备聚乙烯醇缩甲醛的优化配方及工艺条件为:聚乙烯醇26.2g、甲醛4g、淀粉5.4g、尿素3g、改性剂3g、水120g,pH值为2～3,反应温度80～85℃。制得的聚乙烯醇缩甲醛胶粘剂具有粘度大、初粘性好、干燥速度快、稳定性好及游离甲醛含量低等优点,是一种良好的啤酒瓶贴标用胶粘剂。

A preparing process of polyvinyl formal adhesives was introduced with polyvinyl alcohol, formaldehyde and starch as main raw materials. Effect of used amount of formaldehyde, starch ,urea and the modifier,pH value and reaction temperature on preparing and properties of the polyvinyl formal adhesives was discussed. The optimum formula and process conditions are as follows: polyvinyl alcohol 26. 2 g, starch 5. 4 g, water 120g,formaldehyde 4g,urea 3g,modification agent 3g,pH 2-3 and reaction temperature(80 - 85 )℃. The advantages of obtained polyvinyl formal adhesives are higher viscosity, good initial tack, fast drying rate, good stability, water soluble and law content of formaldehyde. This adhesives is a good one for labeling beer bottles.