The Properties of Water Born Thermoplastic Adhesive for Hot Stamping Multilayer Films

The possibility to use water-born adhesive based on the copolymer of vinyl ester of synthetic saturated monocarboxylic acid, methylmethacrylate and 2-ethylhexylacrylate (VeoVa-10/MMA/2-EHA) modified with titanium dioxide, for the multilayer structures of hot stamping has been investigated. It is shown that for the unfilled adhesive compositions dilatant behaviour under shear flow condition is characteristic. The filling changes viscosity of dispersion and enables to facilitate technological adhesive layer coating procedures. The evaluation of adhesion properties by indirect method indicates changes of failure mode when adhesive layer thickness increases. The increase of unfilled adhesive layer thickness increases stamps covering irregularities and decreases its boundary zone quality. The optimal layer thickness was found to be 2 mm. The obtained results confirmed the effect of disperse filling as a way to change adhesion and mechanical properties of multilayer structure. The effective amount of disperse filler allows to obtain stamps which bonding quality are close to those of standard. Besides, the increase of filler content in adhesive composition results on the formed stamps hardness changes. The measurements of modulus and break parameters show non monotonous influence of filler content.