Silanos con funciones azocarbonilo

Silanos con funciones azocarbonilo de la fórmula general I: (R1)3-a(R2)aSi-RI-NH-C(O)-N>=N-R4 (I), donde R1 son independientemente entre sí grupos alquilo C1-C18, grupos cicloalquilo C5-C18- o grupos arilo C6- C18, no sustituidos, R2 es independientemente entre sí un -OH, un grupo alcoxi C1-C18 no sustituido, un grupo cicloalcoxi C5- C18 o un grupo alquil poliéter O(CH2-CH2-10 O)n-R3 u O(CH(CH3)-CH2-O)n-R3, donde el promedio de n es de 1 a 18 y R3 es mutuamente independientemente una cadena hidrocarbonada C1-C32, monovalente, ramificada o no ramificada, saturada o insaturada, RI es un hidrocarburo C1-C30 divalente, alifático, aromático o alifático/aromático mixto, ramificado o no ramificado, saturado o insaturado, a >= 1, 2 o 3, R4 es arilo no sustituido, halogenofenilo, tolilo, alcoxifenilo, o-, m- o p-nitrofenilo, alquilo no sustituido, nitrometilo, nitroetilo, nitropropilo, nitrobutilo o nitro-iso-butilo. The invention provides azocarbonyl-functionalized silanes of the general formula I (R 1 ) 3-a (R 2 ) a Si-R I -NH-C(O)-N=N-R 4 . They are prepared by a procedure in which in a first step hydrazine of the formula H 2 N-NH-R 4 reacts with an isocyanatosilane of the general formula (R 1 ) 3-a (R 2 ) a Si-R I -NCO, and in a second step the product of the first step is oxidized with an oxidant, or in which in a first step hydrazine of the formula H 2 N-NH-R 4 reacts with an acyl halide of the general formula Cl-C(O)-O-R 5 , in a second step the product of the first step is oxidized with an oxidant and in a third step the product of the second step reacts with an aminosilane of the general formula (R 1 ) 3-a (R 2 ) a Si-R I -NH 2 . It may be used for moldings.