Polymerisation initiators, polymerisable compositions, and uses thereof for bonding low surface energy substrates

Abstract

Quaternary boron salts are used as initiators of polymerisation in adhesive compositions for bonding low surface energy substrates such as polyolefins. The quaternary boron salts are of the formula I 1 wherein R1 is C1-C10 alkyl, R2, R3 and R4, which may be the same or different, are, C1-C10 alkyl or C3-C10 cycloalkyl, phenyl, or phenyl-substituted C1-C10 alkyl or C3-C10 cycloalkyl, provided that any two of R1-R4 may optionally be part of a carbocyclic ring, and M+ is a metal ion or a quaternary ammonium ion. When M+ is a quaternary ammonium ion, the initiator may be used in a two-part composition having a (meth)acrylate monomer in both parts and the initiator compound in one part, the two parts being in a weight ratio of about 1:1. Particular examples of initiator compounds include sodium tetraethyl borate, lithium tetraethyl borate, lithium phenyl triethyl borate, tetramethylammonium phenyl triethyl borate, and tetra methyl ammonium phenyl tri-n-butyl borate, the last-mentioned of which is a novel compound.

Dependencies are inferred from the claim text.