The present invention relates to diaminotriazine compounds and to their use as herbicides. It also relates to agrochemical compositions for crop protection and to a method for controlling unwanted vegetation. wherein p is 1 or 2; q is 0, 1, 2 or 3 provided that p+q is 1, 2, 3 or 4; Q is inter alia a chemical bond, O, S(O)m, CRq1Rq2, NRq3, C(O), C(O)O, Ar is phenyl, which is unsubstituted or carries 1, 2, 3, 4 or 5 radicals RA Ra is inter alia hydrogen, halogen, OH, CN, amino, NO2, C1-C6-alkyl, etc; Rb is inter alia halogen, OH, CN, amino, NO2, C1-C6-alkyl, etc.; R1 and R2 are inter alia H, OH, S(O)2NH2, ON, C1-C6-alkyl, etc; X is a radical selected from the group consisting of CR3R4R5, phenyl, which is unsubstituted or carries 1, 2, 3, 4 or 5 radicals RAr; NR3aR3b, OR3c, S(O)kR3d, k being 1, 2 or 3; and including their agriculturally acceptable salts.