申请人:National Starch and Chemical Corporation
公开号:US04703116A1
公开(公告)日:1987-10-27
Polysaccharide aldehydes having the formula Sacch--O--CH.sub.2 --CH.dbd.CH--CHO, ##STR1## such as starch, cellulose, and gum aldehydes, are useful for imparting wet, dry, or temporary wet strength to paper. They are prepared by a non-oxidative method which involves reacting the polysaccharide base, in the presence of alkali, with a derivatizing acetal reagent having the general structure ##STR2## and then hydrolyzing the acetal by adjusting the pH to less than 7, preferably 2-4. In the formulas, n is 1-3; R.sup.11 and R.sup.12 are independently an alkyl, aryl, aralkyl, or alkaryl group when n is 1, R.sup.11 or R.sup.12 is one of the groups when n is 2, or R.sup.11 and R.sup.12 are not present when n is 3; R.sup.13 is an alkyl group, optionally containing an ether linkage, or an aralkyl group; R.sup.14 and R.sup.15 are individually a hydrogen or a methyl group; R.sup.16, R.sup.17, and R.sup.18 are individually an alkyl group; Y- is an anion; Z is an organic group capable of reacting with the polysaccharide base to form an ether derivative and selected from the group consisting of an epoxide, ethylenically unsaturated group, halohydrin, and halogen; R.sup.19, if present, is a divalent organic group containing no reactive substituents; and A and A'0 are lower alkyls or together form at least a 5-membered cyclic acetal.
具有Sacch-O-CH.sub.2-CH.dbd.CH-CHO式的
多糖醛,例如淀粉、
纤维素和
胶醛,可用于赋予纸张湿强度、干强度或临时湿强度。它们通过一种非氧化方法制备,该方法包括在碱的存在下,使用具有一般结构##STR2##的衍生
乙缩醛试剂与
多糖基反应,然后通过将pH调整为小于7,优选为2-4,
水解
乙缩醛来制备。在公式中,n为1-3;当n为1时,R.sup.11和R.sup.12独立地为烷基、芳基、芳基烷基或烷芳基基团,当n为2时,R.sup.11或R.sup.12为其中之一,当n为3时,R.sup.11和R.sup.12不存在;R.sup.13是烷基,可选地含有醚键,或是芳基烷基;R.sup.14和R.sup.15分别是氢或甲基基团;R.sup.16、R.sup.17和R.sup.18分别是烷基基团;Y-是阴离子;Z是有机基团,能够与
多糖基反应形成醚衍
生物,并从卤代醇、
环氧化物、
乙烯基不饱和基团和卤素中选择;如果存在,R.sup.19是不含反应性取代基的二价有机基团;而A和A'0是低级烷基,或共同形成至少一个5环
缩醛。