A molded plastic body is produced from a cured reaction mixture. The reaction mixture is pourable in a non-cured state and includes 50 to 90% by weight, based on the reaction mixture, of an inorganic particulate filler, a crosslinking agent, and 10 to 50% by weight, based on the reaction mixture, of a binder solution. The binder solution includes a monomer and a polymer dissolved in it. The molded plastic body is characterized in that the percentage of the crosslinking agent admixed with the binder solution is more than 10% by weight based on the percentage of the monomer in the binder solution. The invention also relates to a method for producing the molded plastic body.