A binder for composite material comprising cellulose- or lignocellulose-containing material, which is at least based on the components (i) at least one binder from the series consisting of at least one natural or near-natural binder from the series consisting of the vegetable proteins, tannins, potato pulp or an aqueous wheat protein product or a mechanically enzymatically digested potato pulp, and (ii) at least one composition based on an aminoalkylsilane, wherein the aminoalkylsilane is selected from an aqueous solution which contains at least one aminoalkylsilane of the formula R 1 R 2 N(CHR 4) a Si(R 3) r 3-r, in which groups R 1 and R 2 are identical or different and in each case are H or a linear, branched or cyclic C 1 - to C 20 -alkyl group or an aryl group or an aminocarbyl group, it being possible for groups R 1 and R 2 to be optionally substituted, R 3 is H or a linear or branched C 1 -C 8 -alkyl group, groups R 4 are identical or different and R 4 is H or methyl, a is from 1 to 10, groups R are identical or different and R is H and r is 0 or 1 or 2, or at least one cocondensate of at least one aminoalkylsilane of the general formula and at least one further functional silane of the general formula R 7 (CHR 6) b Si p 3-p, in which R 7 is H or a vinyl group or an amino group or a glycidyloxy group or an acryloyloxy group or a methacryloyloxy group or a mercapto group or a sulfane group or a linear or branched C 1 - to C 20 -alkyl group or an aryl group, it being possible for the group R 7 to be optionally substituted, groups R 6 are identical or different and R 6 is H or methyl, b is from 0 to 18, R 5 is H or a linear or branched C 1 - to C 8 -alkyl group, groups R are identical or different and R is H and p is 0 or 1 or 2, it being possible for the amino functions in the cocondensate to be partly or completely neutralized with an inorganic or organic acid, wherein the aminoalkylsilane-containing aqueous solution is substantially an alcohol-free completely hydrolysed product of at least one aminoalkylsilane compound according to the formula, wherein the alcohol content being less than 3% by weight and, wherein the water content is from 5 to 99,5% weight based on the binder composition, wherein the respective components of the agent summing to 100% by weight. (i) at least one binder from the series consisting of at least one natural or near-natural binder from the series consisting of the vegetable proteins, tannins, potato pulp or an aqueous wheat protein product or a mechanically enzymatically digested potato pulp, and (ii) at least one composition based on an aminoalkylsilane, wherein the aminoalkylsilane is selected from an aqueous solution which contains at least one aminoalkylsilane of the formula R 1 R 2 N(CHR 4) a Si(R 3) r 3-r, in which groups R 1 and R 2 are identical or different and in each case are H or a linear, branched or cyclic C 1 - to C 20 -alkyl group or an aryl group or an aminocarbyl group, it being possible for groups R 1 and R 2 to be optionally substituted, R 3 is H or a linear or branched C 1 -C 8 -alkyl group, groups R 4 are identical or different and R 4 is H or methyl, a is from 1 to 10, groups R are identical or different and R is H and r is 0 or 1 or 2, or at least one cocondensate of at least one aminoalkylsilane of the general formula and at least one further functional silane of the general formula R 7 (CHR 6) b Si p 3-p, in which R 7 is H or a vinyl group or an amino group or a glycidyloxy group or an acryloyloxy group or a methacryloyloxy group or a mercapto group or a sulfane group or a linear or branched C 1 - to C 20 -alkyl group or an aryl group, it being possible for the group R 7 to be optionally substituted, groups R 6 are identical or different and R 6 is H or methyl, b is from 0 to 18, R 5 is H or a linear or branched C 1 - to C 8 -alkyl group, groups R are identical or different and R is H and p is 0 or 1 or 2,