Matte-finished polymethacrylate films

A polymethacrylate film having a matte finish, and comprised of:

• (A) a thermoplastic polymer matrix A, in the amount of 30-99.9 wt. %, comprised of:
• a1) 10-95 wt. % of a coherent hard phase with a glass transition temperature >70° C., comprised of:
• a11) 80-100 wt. % (of a1) of methyl methacrylate;
• and
• a12) 0-20 wt. % of one or more other ethylenically unsaturated, radically polymerizable monomers;
• and
• a2) 5-90 wt. % of a tough phase distributed in the hard phase and having a glass transition temperature <−10° C. and a mean particle size of less than 130 nm, comprised of:
• a21) 50-99.5 wt. % (of a2) of an alkyl acrylate wherein the alkyl group has 1-10 C atoms;
• a22) 0.5-6 wt. % of a crosslinking monomer and/or graft crosslinking agent having 2 or more ethylenically unsaturated, radically polymerizable groups;
• and
• a23) optionally one or more of other ethylenically unsaturated, radically polymerizable monomer;
• whereby at least 15 wt. % of the hard phase (a1) is covalently linked with the tough phase (a2);
• wherein, in order to produce the matte-finish effect, the film is further comprised of:
• (B) bodies comprised of thermoelastic polymer B, in the amount of 0.1-70 wt. %, heterogeneously distributed in the thermoplastic matrix polymer A, wherein the polymer B has a mean particle size of 1 to 150 microns and is comprised of:
• b1) 50-99.5 wt. % (of B) of an alkyl methacrylate wherein the alkyl group has 1-6 C atoms;
• b2) 0.5-10 wt. % of a crosslinking monomer having 2 or more ethylenically unsaturated, radically polymerizing groups;
• and
• b3) optionally other ethylenically unsaturated, radically polymerizable monomers;
• and in that the difference between the index of refraction nD,A of the thermoplastic matrix polymer A and the index of refraction nD,B of the heterogeneously distributed bodies comprised of polymer B is at most nD=0.02.