Abstract: Quaternary ammonium salts of the formulaR.sub.1 --K.sup..sym. A.sup..crclbar.in whichR.sub.1 denotes C.sub.12 -C.sub.26 -alkyl or C.sub.12 -C.sub.26 -alkenyl,K.sup..sym. denotes a group of the formula ##STR1## or --.sup..sym. N(R.sub.2).sub.3, R.sub.2 denotes C.sub.1 -C.sub.3 -alkyl, preferably methyl, and A.sup..crclbar. denotes an anion of one of the following formulae: R.sub.3 SO.sub.3.sup..crclbar., in which R.sub.3 is C.sub.6 -C.sub.9 -alkyl or alkenyl and the sum of C atoms in R.sub.1 and R.sub.3 should be at least 21; ##STR2## in which Hal is fluorine, chlorine, bromine or iodine, R.sub.4 is C.sub.1 -C.sub.5 -alkyl, C.sub.2 -C.sub.5 -alkenyl or C.sub.1 -C.sub.5 -alkoxy in positions 3, 4, 5 or 6, R.sub.5 is hydrogen or hydroxyl in positions 2 or 3, R.sub.6 is COO.sup.- or SO.sub.3.sup.- and R.sub.7 is hydrogen or methyl, with the exception of the salicylate and m-halogenobenzoate ions when combined with C.sub.16 -alkylpyridinium and C.sub.16 -alkyltrimethylammonium.

Abstract: Compounds of the general formula ##STR1## in which X represents a trifluoromethyl group or a fluorine atom, n is 1 or 2, Z is an oxygen atom or a NR grouping, in which R is hydrogen or an optionally substituted alkyl group, the benzo rings optionally containing further nonchromophoric substituents. These compounds may be prepared by reacting the dichloride of 1,4-naphthalene-dicarboxylic acid with 2 mols of an o-aminophenol or of an o-nitroaniline and by subsequently cyclizing the acylamino compound obtained. The products are suitable as optical brighteners.

Abstract: A compound of the formula (1) ##STR1## in which X and X' stand for an optionally functionally modified carboxy or sulfo group and wherein the naphthalene nuclei may carry further non- chromophoric substituents and a process for their preparation. These compounds are valuable optical brighteners and can be applied by the methods known in this field.

Abstract: Compounds of the general formula I ##STR1## in which R represents hydrogen or a lower alkyl radical which may be further substituted, n is an integer of from 1 to 4, and which may contain further non-chromophoric substituents. They are prepared by reaction of the dichloride of naphthalene-1,4-dicarboxylic acid with an o-aminophenol and subsequent ring closure. These compounds can be used as optical brighteners.

Abstract: Monostyryl-1-naphthalenes and analogous compounds having a naphthalene, thiophene, furane or pyridine nucleus instead of the phenyl moiety of the styryl residue, which are obtained by the Horner synthesis, are useful as optical brighteners.

Abstract: Compounds of the formula ##SPC1##Wherein R' is carboxy, lower carboalkoxy or lower carboalkoxy substituted by lower dialklamino or lower trialkylammonium and Ar is phenyl substituted by cyano, carboxy or lower carboalkoxy. These compounds show a characterized fluorescence when dissolved and are suitable for the optical brightening of different organic materials such as lacquers or synthetic fibres, for example fibres made of acetyl cellulose, polyesters, polyolefines, polyvinyl chloride or polyvinylidene chloride and films, foils, ribbons or shaped articles made from these materials.