Abstract
Etching mechanisms of ABS and polypropylene resins (used for metallizing) were studied by means of infra-red spectra and gas chromatography.
The results of experiments were as follows.
1) When ABS resin was etched with high concentrated mixture of sulfuric and chromic acids, only butadiene particles were preferentially oxidized and dissolved into the etching reagent to form a long chained saturated hydrocarbon. On the contrary, when it was etched with the above mixture of low concentration, AS matrix as well as butadiene was attacked and dissolved into the reagent to form benzoic acid. Under the both conditions of etching, polar groups were formed on the surface layer of the resin.
2) When polypropylene was etched with the same mixture, the surface layer was oxidized to form polar groups and dissolved into the reagent to form long chained hydrocarbons having CHO and COOH groups.
