a procedure for the production of a modified acrylic sheet with high impact resistance , of the type in which a prepolymerization is done of a mix of monomers with a polymer of dissolved dienic monomers . the procedure is done in batches at low temperatures without there being a separation of the polymer of dienic monomers from the rest of the mix . the procedure facilitates obtaining a modified acrylic sheet with high impact resistance whose transmittance is kept after being subjected to an accelerated degradation , and whose impact properties are not reduced more than 50 % after said accelerated degradation .