The present invention relates to a compound of general formula (I)wherein: X=S, SO or SO2, and； one of the radicals R1 and R2 represents a hydrogen atom and the other one a radical:■ a linear or branched C1-C18 alkyl optionally substituted with one or more halogen atoms,■ a linear or branched C2-C18 alkenyl, optionally substituted with one or more halogen atoms,■ an aralkyl, optionally substituted with one or more C1-C6 alkoxy groups, or■ COR3 or CONHR3, but not simultaneously, wherein R3 represents a radical:a linear or branched C1-C18 alkyl optionally substituted with one or more halogen atoms,a linear or branched C2-C18 alkenyl, optionally substituted with one or more halogen atoms,an aralkyl, optionally substituted with one or more C1-C6 alkoxy groups,an aralkenyl optionally substituted with one or more C1-C6 alkoxy groups and/or OH groups, or elsean aryl radical, optionally substituted with one or more C1-C16 alkoxy groups.本發明係有關於具通式(I)之一化合物其中：X為S、SO或SO2，及；R1與R2基中之一者代表一個氫原子，及另一者代表下列之一基：■ 選擇性地經一或多個鹵素原子取代之一個直鏈或分支的C1-C18烷基，■ 選擇性地經一或多個鹵素原子取代之一個直鏈或分支的C2-C18烯基，■ 選擇性地經一或多個C1-C6烷氧基取代之一芳烷基，或■ COR3或CONHR3，但並非同時，其中R3代表下列之一基：選擇性地經一或多個鹵素原子取代之一個直鏈或分支的C1-C18烷基，選擇性地經一或多個鹵素原子取代之一個直鏈或分支的C2-C18烯基，選擇性地經一或多個C1-C6烷氧基取代之一個芳烷基，選擇性地經一或多個C1-C6烷氧基及/或羥基取代之一個芳烯基，或者選擇性地經一或多個C1-C16烷氧基取代之一個芳基。
