Patent GB-771311-A (GB)
Title: The use of pyrazoline derivatives as fluorescent dyestuffs
Filed: 1953-12-09
Abstract: Coating compositions for application to fibrous material comprise resins, e.g. urea-formaldehyde, melamine-formaldehyde, phenol-formaldehyde, polyvinyl or polyacrylic resins, or nitrocellulose, together with a pyrazoline derivative of the formula <FORM:0771311/IV(a)/1> in which Ar and Ar1 represent aromatic residues which may contain substituents and R1 represents hydrogen or a hydrocarbon radical (see Group IV (b)) and which may contain a sulpho group.  In examples, (1) the sodium salt of a sulphonated 1.5-diphenyl-3-styryl-pyrazoline, alone or mixed with thioflavine, and (2) 1-[41-acetylamino-diphenyl-4]-3-styryl-5-phenyl-pyrazoline are each mixed in water and acetone respectively, with a butanol solution of a urea-formaldehyde resin etherified with butanol, the resin solution is condensed out, the hardened resin ground, and the pigment so obtained is mixed with an alcoholic polyvinyl acetate, polymethacrylate, polystyrene, or nitrocellulose lacquer, which mixture is sprayed on to paper, cardboard or fabric and the coating dried in air.  The coating exhibits intense greenish-yellow fluorescence.ALSO:Pyrazoline derivatives which have the general formula <FORM:0771311/IV(b)/1> in which Ar and Ar1 are aromatic radicals which may be substituted, and R1 is M or a hydrocarbon radical, are made from ketones of the formula Ar1 - CH = CH - CO - CH = CH - R1 and aryl hydrazines of the formula: Ar-NH - NH2 The starting materials may contain sulpho groups or the unsulphonated products may be sulphonated.  The reaction is referred to of (1) dibenzal-acetone and phenylhydrazine to give 1.5 - diphenyl - 3 - styryl - pyrazoline, which is sulphonated; (2) dibenzal-acetone and 41-acetylamino - diphenyl - 4 - hydrazine in glacial acetic acid to give 1-[41-acetylamino-diphenyl-(4)] - 3 - styryl - 5 - phenyl - pyrazoline; (3) dibenzal acetone and p-chlorphenyl hydrazine to give 1 - (p - chlorphenyl) - 3 - styryl - 5 - phenylpyrazoline, and the sulphonation of the latter.  The products are fluorescent in solution or on a substratum.ALSO:Fibrous materials are coloured by dyeing or otherwise incorporating a dyestuff in the material or by applying to the surface of the material a coating composition containing a dyestuff wherein the dyestuff used is a pyrazoline derivative which fluoresces in solution or when applied to a substratum and has the formula:- <FORM:0771311/IV(b)/1> in which Ar and Ar1 represent aromatic residues which may contain substituents, and R1 is hydrogen or a hydrocarbon radical.  The pyrazolines may be water insoluble or sulphated and water-soluble (see Group IV(b)) Ar and Ar1 may be phenyl, or diphenyl, diphenyl ether, and napthalene residues, which may be unsubstituted or contain alkyl, alkoxy, amino, alkyl or acyl-amino, sulpho, or halogen.  R1 may be methyl, ethyl, phenyl, benzyl, or naphthyl.  The water-soluble pyrazolines dye wool, silk, nylon, casein fibres, or fabrics made of mixed nitrogenous fibres, or mixtures of nitrogenous and cellulose fibres.  The water-insoluble pyrazolines dye fibrous materials from organic solvents e.g. in the spinning solution.