Investigations of UV-crosslinkable water-soluble acrylic pressure-sensitive adhesives

Abstract

Titled adhesives based on acrylic acid (AA) or ß-acryloyloxy propionic acid (APA) and butyl acrylate (BA) were synthesized. Unsaturated photoinitiators were introduced into their chains, namely: 4-acryloyloxy benzophenone (ABP), 2-hydroxy-l-[4-(2-acryloyloxy-ethoxy) phenyl]-2-methyl-1-propanone (ZLI 3331) or phenyl-1(1-acryloyloxy)-cyclohexyl ketone (PAC). These products were plastified with polyoxyethylene glycols (PEG) differing in molecular weight (400-1010 Da) or polyoxypropylene glycols (PPG). The effects of chemical compositions of comonomers, plasticizer types and contents as well as effect of pH on the following basing properties of obtained aqueous adhesive systems (PSA) were investigated: water solubility, cohesion and adhesion. Dependence of water solubility of selected plasticized PSAs on UV curing time was also determined. PSA based on 70 wt. % of AA and 30 wt. % of BA with addition of 0.5 wt. % of ABP as photoinitiator/comonomer, plastified with 60-120 phr of PPG has been found as optimal.