Abstract: Nitrogen-containing heterocyclic compounds of the formula II ##STR1## wherein R.sup.1 and R.sup.2 in each case denote an alkyl group having 1 to 15 C atoms, wherein one or more CH.sub.2 groups may also be replaced by a grouping selected from the group comprising --O--, --S--, --CO--, --O--CO--, --O--COO--, --CO--O--, --CH.dbd.CH--, --CH--halogen and --CHCN--, or else by a combination of two suitable groupings, two heteroatoms not being directly linked to each other,m denotes 0 or 1,Ar denotes 1,4-phenylene, 4,4'-biphenylyl or 2,6-naphthylene, wherein one or more CH groups are in each case replaced by N,Z denotes --C--O--, --O--CO--, --CH.sub.2 O--, --OCH.sub.2 --, --CH.sub.2 CH.sub.2 --, --CH.sub.2 CHCN--, --CHCNCH.sub.2 --, --CH.dbd.CH or a single bond, andA denotes unsubstituted 1,4-cyclonexylene or 11,4-cyclohexylene substituted in position 1 or position 4 by CN,with the proviso that if A=unsubstituted 1,4-cyclonexylene, Z denotes --CHCNCH.sub.2 -- or --CH.sub.2 CHCN-- and/or at least one CH.sub.

Abstract: A heat-sealable glass container is heat-sealed by an apparatus which heats the container with an infrared lamp while rotating the container and elongating the heat-softened top portion. The elongation of the softened glass pulls the glass to a point and results in an airtight seal.