Abstract: A metering device for bulk material has a metering container with an outlet opening provided with a rim. A slide is connected to a slide drive and closes the outlet opening. The slide is provided with a slide rim. The rim of the outlet opening and the slide rim, as a function of a displacement travel of the slide in a displacement direction, determine a travel-dependent outlet cross section of the outlet opening. The rim of the outlet opening; or the slide rim; or the rim of the outlet opening and the slide rim extend at a slant to the displacement direction of the slide.

Abstract: Polyether sulphones based on diphenols corresponding to the following general formula (I): ##STR1## wherein R.sup.1 and R.sup.2, independently represent hydrogen, halogen, C.sub.1 -C.sub.8 alkyl, C.sub.5 or C.sub.6 cycloalkyl, C.sub.6 -C.sub.10 aryl, or C.sub.7 -C.sub.12 aralkyl; m represents an integer of from 4 to 7;R.sup.3 and R.sup.4, may be selected individually for each X and independently represent hydrogen or C.sub.1 -C.sub.6 alkyl, andX represents carbon;with the proviso that, on at least one atom X, R.sup.3 and R.sup.4 both represent alkyl,the production thereof, films made from these polyether sulfones, composite films with other plastic materials and application of the films in gas permeation.

Abstract: Polyether ketones based on diphenols corresponding to the following general formula (I): ##STR1## wherein R.sup.1 and R.sup.2, independently represent hydrogen, halogen, C.sub.1 -C.sub.8 alkyl, C.sub.5 or C.sub.6 cycloalkyl, C.sub.6 -C.sub.10 aryl or C.sub.7 -C.sub.12 aralkyl;m represents an integer of from 4 to 7;R.sup.3 and R.sup.4, may be selected individually for each X and independently represent hydrogen or C.sub.1 -C.sub.6 alkyl, andX represents carbon;with the proviso that, on at least one atom, X, R.sup.3 and R.sup.4 both represent alkyl;the production thereof and application as films or composite films with other plastic films as well as their utilization as permeation membranes.