Abstract: The invention provides a new process for the manufacture of aromatic compounds which at least once contain a benzene ring of an aromatic carbocyclic ring system bonded by an ethylene double bond in conjugation with a further aromatic ring system, i.e. contain the stilbene skeleton or stilbene analogon as central structural element, as well as certain classes of new compounds of this type. The process is characterized by the reaction of a Schiff base of an aromatic aldehyde with an aromatic carbocyclic six-membered ring compound which contains one to four methyl groups bonded to ring carbon atoms of a benzene ring, which furthermore contains aromatic rings which are exclusively six-membered carbocyclic rings, and wherein those benzene rings whose methyl groups are to be caused to react are free of other substituents which contain atoms which are replaceable by alkali metal. The reaction is carried out in the presence of (a) a strongly basic alkali compound and (b) an N-dialkyl-acylamide as solvent.

Abstract: Apparatus for depositing liquid droplets in a printing operation employs a member having a receiving surface and being moved at a speed high enough to cause the generation of a gaseous boundary layer along the receiving surface. The stream of droplets is projected at right angles to the rapidly moving receiving surface and a stationary intercepting device is provided to remove, deflect or slow down the boundary layer upstream of the locus where the droplets impinge upon the receiving surface. If the receiving surface is provided on a cylindrical member, the intercepting means may comprise a stationary cylinder surrounding the receiving surface with a clearance of 0.5-2 millimeters. Regardless of the configuration of the receiving surface, the intercepting means may employ one or more stationary deflecting blades or one or more suction nozzles having orifices closely adjacent to the receiving surface immediately upstream of the locus of impingement of droplets.

Abstract: The present invention provides the new bis-stilbene compounds, which are useful as optical brighteners and correspond to the formulaR.sub.1 -- CH = CH -- X -- CH = CH -- R.sub.2in which X represents a diphenyl residue bound in positions 4 and 4' to the =CH-- groups; R.sub.1 and R.sub.2 independently of each other, each represents a monocyclic benzene residue, a diphenyl, naphthyl or pyridyl residue, and in which at least one of the cyclic systems R.sub.1, R.sub.2, X contains a possibly functionally modified sulphonic acid group, a sulphone group, a possibly functionally modified carboxylic acid group, a nitrile, hydroxyl, mercapto or methyl group.

Abstract: The present invention provides new 1,4-distyryl-benzene derivatives corresponding to the formula ##SPC1##Wherein R represents alkyl with 1 to 8 carbon atoms which is optionally substituted by non-chromophoric radicals, phenyl which is optionally substituted by non-chromophoric radicals, alkenyl with 2 to 4 carbon atoms or cycloalkyl with 5 or 6 carbon atoms, X represents hydrogen, chlorine, or alkyl with 1 to 4 carbon atoms, Y and Y' each independently represents hydrogen, chlorine, methyl, methoxy or ethoxy, and n is 1 or 2. The new compounds are valuable optical brighteners for organic materials, especially for polyesters.

Abstract: The present invention provides new bis-oxadiazole compounds of the formula ##EQU1## wherein R.sub.1 and R.sub.1 ' independently of one another represent hydrogen, an optionally non-chromophorically substituted aliphatic, cycloaliphatic or araliphatic radical with up to 18 carbon atoms or an optionally non-chromophorically substituted, at most binuclear, carbocyclic or heterocyclic aromatic radical and Q represents a radical ##SPC1##Wherein a represents hydrogen, halogen, alkyl with 1 to 4 carbon atoms, alkoxy with 1 to 4 carbon atoms, sulpho groups or their salts or an optionally substituted sulphamoyl group or both radicals a together with the diphenylene radical represent a 9,10-dihydrophenanthrene ring and the benzene ring A can optionally be substituted by halogen, alkyl with 1 to 4 carbon atoms, sulpho groups or their salts or an optionally substituted sulphamoyl group or can possess a fused-on six-membered ring.The new compounds are useful optical brighteners for high-molecular organic materials.