Mar resistance, non-glare transparent acrylic sheet with consistent optical properties at various sheet thicknesses

Abstract

Disclosed is a mar resistant transparent co-extruded sheet which is comprised of (a) a cap layer containing particles having a mean particle size of about 1 to 60 microns wherein 90% of the particles are less than 70 microns, at a loading of 0.1 to 18%, melt blended with an acrylic matrix, wherein the particle and matrix have refractive indices within 0.020 units when measured in conformance with ASTM D 542; and (b) a clear substrate layer comprised of an acrylic composition, wherein the substrate has a refractive index within 0.020 units of the refractive index of the cap layer matrix when measured in conformance with ASTM D 542; wherein the co-extruded product has (i) a luminous transmission (CIE tristimulus Y value) of greater than 90% when measuring spectral transmission data using a Macbeth® Color-Eye® 7000 spectrophotometer (Division of Kollmorgen Instruments Corporation), Illuminant C, and the 2° standard observer, and calculating the CIE tristimulus Y value in conformance with ASTM E 308, and (ii) a haze of less than 16% when measured in conformance with ASTM D 1003, and at least one of (iii) or (iv), (iii) a 60° gloss value measured on a 0.118 inch thick sample within 15 units of the 60° gloss value measured on a 0.080 inch thick sample when measured using a micro-TRI-gloss meter made by BYK-Gardner GmbH in conformance with ASTM D 523 using a black felt backing, and (iv) a change in haze as measured in conformance with ASTM D 1044, after 500 revolutions using a 500 g load and CS10F wheel, of less than 25%.