Reactive aqueous polyurea dispersions prepared by an emulsion polymerization process
申请人:Bayer Corporation
公开号:EP0568976A1
公开(公告)日:1993-11-10
The present invention is directed to a process for the preparation of an aqueous polyurea dispersion containing blocked isocyanate groups and unreacted isocyanate-reactive groups by
I) dispersing in water
a) a polyisocyanate which has an average functionality of 1.5 to 4.0 and an isocyanate content of at least 12% by weight,
b) 10 to 70 equivalent percent, based on the isocyanate groups of component a), of a monofunctional blocking agent which is more reactive with isocyanate groups than water and
c) an amine component containing
i) 2 to 55 equivalent percent of a polyamine having at least two primary and/or secondary amino groups and a molecular weight of at least 1000,
ii) 5 to 70 equivalent percent of a polyamine having at least two primary and/or secondary amino groups, a molecular weight of less than 400 and at least one anionic or potential anionic group and
iii) up to 70 equivalent percent of an isocyanate-reactive compound having a molecular weight of less than 400 and containing at least one primary or secondary amino group and at least one other isocyanate-reactive group,
wherein the equivalent percents of component c) are based on the total equivalents of isocyanate-reactive groups present in component c) and wherein the polyurea contains an equivalent ratio of blocked isocyanate groups to unreacted isocyanate-reactive groups of 2:1 to 0.8:1, and
II) reacting the polyisocyanate with components b) and c) to form an aqueous polyurea dispersion.
The present invention is also directed to the aqueous polyurea dispersion prepared by this process.
本发明涉及通过以下方法制备含有封端异氰酸酯基团和未反应异氰酸酯反应基团的水性聚脲分散体的工艺过程
I) 在水中分散
a) 多异氰酸酯,其平均官能度为 1.5 至 4.0,异氰酸酯含量至少为 12%(按重量计)、
b) 以 a 组份的异氰酸酯基团为基准,10%-70% 的单官能团封端剂,该封端剂与异氰酸酯基团的反应性比与水的反应性强,以及
c) 含有以下成分的胺组分
i) 2 至 55%当量的多胺,至少有两个伯氨基和/或仲氨基,分子量至少为 1000、
5 至 70%的多胺,至少有两个伯氨基和/或仲氨基,分子量小于 400,至少有一个阴离子或潜在阴离子基团,以及
iii) 分子量小于 400 且含有至少一个伯氨基或仲氨基和至少一个其它异氰酸酯 反应基团的异氰酸酯反应性化合物,最高含量为 70%、
其中,组分 c) 的当量百分数基于组分 c) 中存在的异氰酸酯反应基团的总当量,且聚脲含有封端异氰酸酯基团与未反应的异氰酸酯反应基团的当量比为 2:1 至 0.8:1,以及
II) 将多异氰酸酯与成分 b) 和 c) 反应,形成水性聚脲分散体。
本发明还涉及通过该工艺制备的水性聚脲分散体。