Normally tacky, pressure sensitive adhesive compositions comprise one or more polymers having a Tg of about 0° C. or less containing at least about 40 weight percent polymerized, olefinically unsaturated carboxylic acid esters monomers and pendant functional groups attached to a polymer backbone and having the formula:
in which R₁ is a divalent organic radical at least 3 atoms in length, and X is organoacyl or cyano. Such polymers have markedly improved cohesive strength (shear holding value) with little or no detriment to adhesive tack or adhesion (peel resistance), and these improvements are realized without the necessity of incorporating cross-linking monomers such as N-methylolamides or other cross-linking agents. Pressure sensitive adhesives, water-based emulsions containing such polymers and adhesive articles having at least a portion of one surface thereof coated with such adhesive are also provided.
通常具有粘性的压敏粘合剂组合物由一种或多种聚合物组成,其 Tg 约为 0°C 或更低,含有至少约 40 重量百分比的聚合烯烃不饱和
羧酸酯单体和连接到聚合物骨架上的悬挂官能团,并具有以下式子:
其中 R₁ 是长度至少为 3 个原子的二价有机基,X 是有机酰基或
氰基。这种聚合物的内聚强度(剪切保持值)显著提高,而对粘合剂的粘性或附着力(抗剥离性)几乎没有影响,而且无需加入交联单体(如 N-甲基酰胺或其他
交联剂)即可实现这些改进。此外,还提供了压敏型粘合剂、含有此类聚合物的
水基乳液以及至少有一部分表面涂有此类粘合剂的粘合物品。