A process for the production of a thermoplastic molding composition comprising: a) from 55 to 85% by weight of at least one copolymer A composed of at least one vinylaromatic monomer A1, and also of at least one α,β-unsaturated monomer A2; b) from 15 to 45% by weight of at least one graft copolymer B with average particle size from 50 to 550 nm, composed of: from 60 to 80% by weight of at least one rubbery graft base B1 consisting of: B11: from 80 to 99% by weight of at least one C2-C8-alkyl acrylate, B12: from 0.5 to 2.5% by weight of the cyclic crosslinking agent dicyclopentadienyl acrylate, B13: from 0 to 2.0% by weight of another, noncyclic crosslinking agent comprising at least two functional groups, B14: from 0 to 18% by weight of another copolymerizable monomer; and from 20 to 40% by weight of at least one graft shell B2 consisting of: B21: from 60 to 75% by weight of an optionally substituted styrene, B22: from 25 to 40% by weight of acrylonitrile, B23: from 0 to 9% by weight of another copolymerizable monomer; c) from 0 to 10% by weight of other auxiliaries and/or additives C; where the entirety of components A to C provides 100% by weight of the molding composition, and where the reaction time of the polymerization for the production of the graft base B1 is in the range from 2 to 5 h and addition of the starting materials takes place across at least two chronological segments. a) from 55 to 85% by weight of at least one copolymer A composed of at least one vinylaromatic monomer A1, and also of at least one α,β-unsaturated monomer A2; b) from 15 to 45% by weight of at least one graft copolymer B with average particle size from 50 to 550 nm, composed of: from 60 to 80% by weight of at least one rubbery graft base B1 consisting of: B11: from 80 to 99% by weight of at least one C2-C8-alkyl acrylate, B12: from 0.5 to 2.5% by weight of the cyclic crosslinking agent dicyclopentadienyl acrylate, B13: from 0 to 2.0% by weight of another, noncyclic crosslinking agent comprising at least two functional groups, B14: from 0 to 18% by weight of another copolymerizable monomer; and from 20 to 40% by weight of at least one graft shell B2 consisting of: B21: from 60 to 75% by weight of an optionally substituted styrene, B22: from 25 to 40% by weight of acrylonitrile, B23: from 0 to 9% by weight of another copolymerizable monomer; from 60 to 80% by weight of at least one rubbery graft base B1 consisting of: B11: from 80 to 99% by weight of at least one C2-C8-alkyl acrylate, B12: from 0.5 to 2.5% by weight of the cyclic crosslinking agent dicyclopentadienyl acrylate, B13: from 0 to 2.0% by weight of another, noncyclic crosslinking agent comprising at least two functional groups, B14: from 0 to 18% by weight of another copolymerizable monomer; B11: from 80 to 99% by weight of at least one C2-C8-alkyl acrylate, B12: from 0.5 to 2.5% by weight of the cyclic crosslinking agent dicyclopentadienyl acrylate, B13: from 0 to 2.0% by weight of another, noncyclic crosslinking agent comprising at least two functional groups, B14: from 0 to 18% by weight of another copolymerizable monomer; and from 20 to 40% by weight of at least one graft shell B2 consisting of: B21: from 60 to 75% by weight of an optionally substituted styrene, B22: from 25 to 40% by weight of acrylonitrile, B23: from 0 to 9% by weight of another copolymerizable monomer; B21: from 60 to 75% by weight of an optionally substituted styrene, B22: from 25 to 40% by weight of acrylonitrile, B23: from 0 to 9% by weight of another copolymerizable monomer; c) from 0 to 10% by weight of other auxiliaries and/or additives C;