Carboxylic acids with additional oxygen function, their anhydrides, halides, peroxides and peroxyacids and their halogenated, sulphonated, nitrated or nitrosated derivatives (excl. only with alcohol, phenol, aldehyde or ketone function, and 2,6dimethoxybenzoic acid, dicamba [iso], sodium phenoxyacetate, and 2,4,5t [iso] [2,4,5trichlorophenoxyacetic acid] and its salts and esters)