申请人:Seton Company
公开号:EP0246723A2
公开(公告)日:1987-11-25
A method of mechanically frothing and casting an aqueous polyurethane dispersion yields a foam which, when rolled, wound or stacked, is self-releasing from the pressure sensitive adhesive layer co-cured therewith. The method includes admixing an aqueous ionic polyurethane dispersion with a stearate stabilizer and an optional aziridine crosslinking agent, frothing and casting the admixture, and co-curing the resultant foam sheet with a pressure sensitive adhesive layer. Before frothing, the polyurethane dispersion contains particles having an average size of less than one micron, and contains between 35 and 70 percent by weight of the polyurethane dispersion, between 13 and 50 percent by weight of a 33 percent by weight dispersion of a stearate salt, and up to 33 percent by weight of a polyfunctional aziridine. The foam produced from the frothed admixture provides a substrate with which an uncured pressure sensitive adhesive can firmly co-cure but to which the cured adhesive demonstrates readily removable adhesion. The laminate of the foam with a pressure sensitive adhesive thus provides either a medical dressing, or a general purpose tape for industrial use, which may be stacked or self-wound without release paper.
一种对水性聚氨酯分散体进行机械发泡和浇注的方法可产生一种泡沫,该泡沫在卷绕、缠绕或堆叠时,可从与之共固化的压敏胶层中自释放。该方法包括将水性离子聚氨酯分散体与硬脂酸稳定剂和可选的氮丙啶交联剂混合,发泡和浇注混合物,并将所得泡沫板与压敏胶层共同固化。发泡前,聚氨酯分散体含有平均粒径小于一微米的颗粒,并含有重量百分比为 35% 至 70% 的聚氨酯分散体、重量百分比为 13% 至 50% 的硬脂酸盐分散体和重量百分比为 33% 的多官能团氮丙啶。由起泡的混合物产生的泡沫提供了一种基材,未固化的压敏胶可与之牢固地共同固化,但固化后的胶粘剂显示出易于去除的粘附性。因此,泡沫与压敏胶的层压可以提供医用敷料,也可以提供工业用的通用胶带,这种胶带可以堆叠或自行缠绕,而不需要离型纸。