栲胶的化学改性及其产物在无铬少铬鞣法中的应用  

Chemical modifications of vegetable extracts and applications of the products in chrome-free and chrome-reduced tannages

作　　者：石碧[1] 狄莹[1] 宋立江[1] 黄文[1] 杜光伟[1] 何有节[1] 

机构地区：[1]四川大学皮革化学与工程教育部重点实验室,成都610065

出　　处：《中国皮革》2001年第9期3-8,共6页China Leather

基　　金：高等学校博士学科点专项基金 !(1 9990 61 0 2 5)

摘　　要：栲胶 -金属离子结合鞣法可以生产具有高湿热稳定性的皮革 ,但这类对环境友好的鞣制技术至今仍未在轻革生产中得到广泛应用。主要原因是 ,为了保证栲胶在裸皮中的均匀渗透 ,其用量一般应在 15%以上 ,而这一用量必然导致成革具有较强的植鞣感 (重而且过度紧实 )。本论文证实了 ,通过对栲胶进行适当的化学改性 ,可以基本消除这一不利因素。凝缩类单宁适宜采用深度亚硫酸化改性 ;水解类单宁适宜采用氧化降解改性。这两种改性方法均导致单宁的分子量降低 ,同时又可以增加降解产物 -金属离子结合鞣的化学协同效应。改性栲胶的用量为 5%～ 10 %时 ,即可以很快渗透裸皮与 1.0 %的 Cr2 O3结合鞣 ,可使成革的 Ts>110℃ ,鞣制废液中的铬含量显著降低。由于栲胶用量减少 ,成革的植鞣感基本消除。本文翔实地描述了栲胶的化学改性方法。It is known that high shrinkage temperature leathers can be produced using vegetable tannin metal combination tannages. But these cleaner technologies have not been widely used because the leathers always exhibit heavy and over tight properties. Primary reason for these is that at least 15% vegetable extract should be used for full penetration, the offer leading to “vegetable tanned character”. In this paper, it was shown that the impediment could be subjugated by chemical modifications of vegetable tannins. The proper method for condensed tannins is intensive sulfitation using Na 2SO 3 and that for hydrolysable tannins is controlled oxidation using H 2O 2. They both bring about molecular degradation of tannins; meanwhile the synergistic effect of the modified products with metal ions is enhanced. As a result, 5%～10% tannin compound can easily penetrate through pelt. Combined with 1.0% Cr 2O 3, leathers with shrinkage temperature above 110℃ were achieved. In such a small offer of vegetable compounds, vegetable tanned character of leathers is largely eliminated. So, based on modifications of vegetable extracts, a series of chrome reduced tannages producing leathers with mineral tanned character were developed in which the chrome content in effluent was markedly reduced. The conditions for the chemical modifications and the applications of the products in chrome reduced and chrome free tannages were described in detail.

关 键 词：制革 无铬少铬鞣法 栲胶 植物单宁 化学改性 

分 类 号：TS529.2[轻工技术与工程—皮革化学与工程]