Crosslinkable compositions based on organosilicon compounds comprising organopolysiloxanes of the formula (R 7 O) 3-a SiR 3 a O(SiR 4 2 O) n SiR 3 a (OR 7) 3-a, where R 4 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, R 7 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, R 3 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, a may be the same or different and is 0 or 1 and n is an integer from 30 to 2000, and siloxanes of the formula where R may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, R 1 may be the same or different and are monovalent hydrocarbon radicals having 2 to 16 carbon atoms, -CH 2 -NR 6 R 5 radicals or -CH 2 NR 11 radicals where R 5 are hydrocarbon radicals having 1 to 12 carbon atoms, R 6 is a hydrogen atom or radical R 5, and R 11 is a divalent hydrocarbon radical which may be interrupted by heteroatoms, R 2 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, x may be the same or different and is 0 or an integer from 1 to 9 and z is 1 or 2, with the proviso that the sum of all x in formula is greater than 0. organopolysiloxanes of the formula (R 7 O) 3-a SiR 3 a O(SiR 4 2 O) n SiR 3 a (OR 7) 3-a, where R 4 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, R 7 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, R 3 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, a may be the same or different and is 0 or 1 and n is an integer from 30 to 2000, and R 4 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, R 7 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, R 3 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, a may be the same or different and is 0 or 1 and n is an integer from 30 to 2000, and siloxanes of the formula where R may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, R 1 may be the same or different and are monovalent hydrocarbon radicals having 2 to 16 carbon atoms, -CH 2 -NR 6 R 5 radicals or -CH 2 NR 11 radicals where R 5 are hydrocarbon radicals having 1 to 12 carbon atoms, R 6 is a hydrogen atom or radical R 5, and R 11 is a divalent hydrocarbon radical which may be interrupted by heteroatoms, R 2 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, x may be the same or different and is 0 or an integer from 1 to 9 and z is 1 or 2, with the proviso that the sum of all x in formula is greater than 0. R may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, R 1 may be the same or different and are monovalent hydrocarbon radicals having 2 to 16 carbon atoms, -CH 2 -NR 6 R 5 radicals or -CH 2 NR 11 radicals where R 5 are hydrocarbon radicals having 1 to 12 carbon atoms, R 6 is a hydrogen atom or radical R 5, and R 11 is a divalent hydrocarbon radical which may be interrupted by heteroatoms, R 2 may be the same or different and are monovalent, optionally substituted hydrocarbon radicals, x may be the same or different and is 0 or an integer from 1 to 9 and z is 1 or 2, with the proviso that the sum of all x in formula is greater than 0.