Transparent impact styrene polymer structure

摘要

An improved resinous structure is disclosed. The structure has a transparent resinous matrix having a light absorbance (optical density) at 640 millimicrons wavelength which is not greater than 0.07 when the structure has a thickness of 10 mils. The continuous matrix polymer is a polymer of about 65 to 95 parts by weight of styrene and 5 to 35 parts by weight of methylmethacrylate. The structure contains a discontinuous phase of a diene rubber in a proportion of about 4 to 12 parts by weight. The rubber is present in the form of particles having an average diameter not exceeding 2 microns, the particles are of a cellular nature and principally of a closed-cell configuration. The cell walls of the particles are not greater than about 0.15 microns in thickness. The rubber particles contain, occluded therein, polymer of a composition generally identical to the matrix polymer. Such resinous bodies are transparent, impact resistant and suitable for many packaging applications.