Process for preparing acrylamidoalkyl-functional silanes and mixtures of these, by - reacting an aminoalkyl-functional alkoxysilane of the formula I or a mixture comprising at least two silanes of the formula I (R 1 O) 3-a-b (R 2) a Si 1+b where the group B in formula I independently corresponds to a group of the formula II -(CH 2) c -[ (CH 2) d] e [ (CH 2) f] g NH (2-h) R 3 h in formula I with R 1 independently a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, especially having 1, 2, 3 or 4 carbon atoms, R 2 independently a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, and in formula II with R 3 independently a linear, branched or cyclic alkyl, aryl or alkylaryl group having 1 to 8 carbon atoms, and in formula I a is independently 0 or 1, b is independently 0, 1 or 2, in formula II c is independently selected from 1, 2, 3, 4, 5 and 6, d is independently selected from 1, 2, 3, 4, 5 and 6, e is independently selected from 0, 1, 2, 3, 4, 5 and 6, f is independently selected from 1, 2, 3, 4, 5 and 6, g is independently selected from 0, 1, 2, 3, 4, 5 and 6, and h is independently 0 or 1, or the group B in formula I corresponds to a group of the formula III -(CH 2) j -NH 2-p (CH 2 -CH 2 -NH 2) p with j = 1, 2 or 3 and p = 0, 1 or 2, - with acrylic anhydride of the formula IV (CHR 5 =CR 4 CO) 2 O where R 4 is independently a hydrogen atom or a methyl group and R 5 is independently a hydrogen atom or a methyl group, and where the reaction is effected with a solvent or diluent content in the overall composition of less than or equal to 1.5% by weight and within a defined temperature range in the absence of a stabilizer, - and acrylic acid and/or reaction products of acrylic acid are optionally removed. - reacting an aminoalkyl-functional alkoxysilane of the formula I or a mixture comprising at least two silanes of the formula I (R 1 O) 3-a-b (R 2) a Si 1+b where the group B in formula I independently corresponds to a group of the formula II -(CH 2) c -[ (CH 2) d] e [ (CH 2) f] g NH (2-h) R 3 h in formula I with R 1 independently a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, especially having 1, 2, 3 or 4 carbon atoms, R 2 independently a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, and in formula II with R 3 independently a linear, branched or cyclic alkyl, aryl or alkylaryl group having 1 to 8 carbon atoms, and in formula I a is independently 0 or 1, b is independently 0, 1 or 2, in formula II c is independently selected from 1, 2, 3, 4, 5 and 6, d is independently selected from 1, 2, 3, 4, 5 and 6, e is independently selected from 0, 1, 2, 3, 4, 5 and 6, f is independently selected from 1, 2, 3, 4, 5 and 6, g is independently selected from 0, 1, 2, 3, 4, 5 and 6, and h is independently 0 or 1, or the group B in formula I corresponds to a group of the formula III -(CH 2) j -NH 2-p (CH 2 -CH 2 -NH 2) p with j = 1, 2 or 3 and p = 0, 1 or 2, - with acrylic anhydride of the formula IV (CHR 5 =CR 4 CO) 2 O where R 4 is independently a hydrogen atom or a methyl group and R 5 is independently a hydrogen atom or a methyl group, and where the reaction is effected with a solvent or diluent content in the overall composition of less than or equal to 1.5% by weight and within a defined temperature range in the absence of a stabilizer, - and acrylic acid and/or reaction products of acrylic acid are optionally removed.