Verwendung von heterocyclischen Verbindungen als Schutzmittel gegen Ultraviolettstrahlung

The invention comprises ultra-violet light screening agents of the formula where R1 is a hydrogen atom, a phenyl group or a saturated hydrocarbon residue with up to 12 carbon atoms, R2 is a hydrogen atom or hydroxyl group, R3 and R4 are identical or different and are a halogen atom, etherified hydroxyl or mercapto group or an amine residue of formula where Z1 is a hydrogen atom, alkyl or hydroxyalkyl group, Z2 is an alkyl, hydroxyalkyl or benzene group or Z1 and Z2 together with the nitrogen atom represent a saturated heterocyclic residue. The compounds are prepared by treating a trihalogeno-1,3,5-triazine with a benzoxazolyl compound of the formula and, if desired, one or both halogen atoms may be further substituted. The benzoxazolyl compounds may be obtained by reacting an ortho-amino phenol with an amino benzenecarboxylic acid, or alternatively an ortho-nitro phenol is reacted with a nitro benzoyl chloride followed by ring closure and reduction to the amino compound with stannous chloride and hydrochloric acid.ALSO:Ultra-violet light screening agents of the formula where R1 is a hydrogen atom, a phenyl group or a saturated hydrocarbon residue with up to 12 carbon atoms, R2 is a hydrogen atom or hydroxyl group, R3 and R4 are identical or different and are a halogen atom, etherified hydroxyl or mercapto group or an amine residue of formula where Z1 is a hydrogen atom, alkyl or hydroxyalkyl group, Z2 is an alkyl, hydroxyalkyl or benzene group or Z1 and Z2 together with the nitrogen atom represent a saturated heterocyclic residue, are used to protect polymers. Polymers exemplified are a titanium dioxide pigmented polyamide from hexamethylenediamine adipate, polyvinyl chloride, polyethylene and polypropylene. Other polymers mentioned are epoxy resins, polyester resins, vinyl resins, polystyrene resins, alkyd resins, aldehyde resins, e.g. condensates from formaldehyde with phenol, urea or melamine, emulsions of synthetic resins, copolymers of vinyl chloride and vinylidene chloride alkyd lacquers, polyamides, polyacrylonitrile and polyesters. In Example 16 a water-soluble pulverulent melamine formaldehyde resin is dissolved in a solution of the compound in dimethyl formamide which has been diluted with 4 parts of water.ALSO:Ultra-violet light screening agents of the formula where R1 is a hydrogen atom, a phenyl group o