Herbicidal 1,2,4,6-thiatriazines

The present invention relates to novel, herbicidally active thiatriazine derivatives, processes for their preparation, compositions comprising these compounds, and their use for controlling weeds, in particular in crops of useful plants, for example cereals, maize, rice, cotton, soya, oilseed rape, sorghum, sugar cane, sugar beet, sunflower, vegetables and fodder plants, or for inhibiting plant growth. Compounds of formula (I), in which R, Rand Rare as defined in claim 1, are particularly suitable as herbicides.