The invention relates to novel benzopyran derivatives of formula I, to their method of production, to composition comprising the derivatives and use thereof. The channels are connectable to respective output devices responsive to the respective actuation signals and located in the field. Surprisingly, the nonwoven webs of the present invention have a tear strength greater than the tear strength of a nonwoven web prepared from the biodegradable aliphatic polyester polymer alone. The TCM coding provided by the present invention is quite effective in dealing with impulse noise effects.