An essentially isocyanate-free polyurethane polyurea polyethylenic oligomer is disclosed which is unusually strong and elastic. This oligomer is the reaction product of: (1) organic diisocyanate; (2) a stoichiometric deficiency of difunctional materials reactive therewith and consisting essentially of: (A) diol component selected from polycarbonate diol and polyoxyalkylene glycol, this diol component having a molecular weight of from 200 to 2000; (B) dihydric bisphenol-based alkylene oxide adduct containing from 2-10 alkylene groups per molecule; and (C) a diprimary diamine component selected from alkylene diamine and polyoxyalkylene diamine, this diamine component having a molecular weight of from about 70 to 800. Components (A) and (B) are present in a weight ratio of from 1:4 to 9:1 and component (C) is present to supply from 30 to 60 equivalent percent of the total equivalents of component (2). The polyurethane polyurea so-constituted is capped with monohydric ethylenic compound, such as 2-hydroxyethyl acrylate, to provide a molecular weight in the range of about 5,000 to about 30,000.
This polyethylenic oligomer is cured by radiation exposure, such as an electron beam, using from 5% to 25%, based on total polymer solids, of a polyethylenic cross-linking agent.
本发明公开了一种基本上不含
异氰酸酯的聚
氨酯聚
脲聚
乙烯低聚物,它具有非同寻常的强度和弹性。这种低聚物是以下物质的反应产物(1) 有机二
异氰酸酯;(2) 与之反应的双官能团材料的
化学计量不足,主要包括(A) 选自聚
碳酸酯二元醇和聚氧亚烷基二醇的二元醇组分,该二元醇组分的分子量为 200 至 2000;(B) 每分子含有 2 至 10 个亚烷基的二
水双
酚基环氧亚烷基加合物;以及 (C) 选自亚烷基二胺和聚氧亚烷基二胺的二元二胺组分,该二元二胺组分的分子量约为 70 至 800。组分(A)和(B)的重量比为 1:4 至 9:1,组分(C)占组分(2)总当量的 30% 至 60%。如此构成的聚
氨酯聚
脲用一
水乙烯基化合物(如
丙烯酸 2-羟乙基酯)封端,以提供分子量在约 5,000 至约 30,000 之间的产品。
这种聚
乙烯低聚物通过辐照(如电子束)固化,使用的聚
乙烯交联剂占聚合物固体总量的 5%至 25%。