一种少氯漂白精制漂白紫胶的工艺

A less chlorine bleaching process for refined bleached shellac

在当前精制漂白紫胶常规漂白方法的基础上,为了得到一种精制漂白紫胶的少氯漂白工艺条件,采用次氯酸盐(H)和过氧化氢漂白(P)相结合的两段漂白方法对紫胶进行漂白制得精制漂白紫胶。通过正交试验探讨了精制漂白紫胶HP漂白工艺过程中次氯酸盐用量,过氧化氢用量,过氧化氢漂白温度及其过氧化氢漂白时间等。结果表明,利用次氯酸盐和过氧化氢漂白相结合的漂程,并且在次氯酸盐用量为5.5%,过氧化氢用量为11.0%,过氧化氢的漂白温度为65℃以及过氧化氢漂白时间为1h时,制得的精制漂白紫胶性能最佳,其主要质量指标为:加纳颜色11号,酸值81.1 mg/g,热乙醇不溶物0.15%,冷乙醇可溶物97.5%,氯含量0.61%,蜡含量0.05%,热硬化时间368s。

Based on the current conventional bleaching process of refined bleached shellac,in order to develop a method that reduces the usage of chlorine,refined bleached shellac was prepared by bleaching process of sodium hypochlorite and hydrogen peroxide(HP).The amount of sodium hypochlorite and hydrogen peroxide,the bleaching temperature and the bleaching time of hydrogen peroxide for refined bleached shellac were studied by orthogonal test.The results showed that the bleaching process of HP combined with sodium hypochlorite and hydrogen peroxide had the best performance when the amount of sodium hypochlorite was 5.5%,the amount of hydrogen peroxide was 11.0%,the bleaching temperature of hydrogen peroxide was 65℃and the bleaching time of hydrogen peroxide was 1 h,the main quality indexes were:Gardner Color was 11#,acid value was 81.1 mg/g,hot alcohol insolubles was 0.15%,cold alcohol solubles was 97.5%,chlorine content was 0.61%,wax content was 0.05%,and hot polymerization time was 368 s.