Patent GB-712764-A (GB)
Title: Improvements in or relating to a process for improving the whiteness or colour of materials
Inventor: KENDALL JOHN DAVID
IPC: G03C1/815
Filed: 1951-09-07
Abstract: A compound of the formula <FORM:0712764/IV (a)/1> where R1 is a substituted or unsubstituted hydrocarbon radical, R2 is hydrogen or a substituted hydrocarbon radical and Ar1 and Ar2, which may be the same or different, are each substituted or unsubstituted aryl radicals, the compound being free from substituent nitro groups and being colourless in aqueous or ethyl alcoholic solution, is included in compositions from which films or fibres are extruded or cast to impart fluorescence.  The fibre or film forming material may be regenerated cellulose, cellulose-nitrate, -acetate, -propionate, -butyrate -acetate-butyrate, -acetate-propionate, a linear polyamide, a vinyl ester, acetal or chloride, a mixed polymer or interpolymer of vinyl derivatives, or gelatin.  Ar1 may be a phenyl or naphthyl radical with hydroxy, alkoxy, hydroxyalkyl, amino, hydrocarbon-substituted amino, acylamino or halogen substituents, Ar2 may be an aromatic radical with hydrocarbon, hydroxy, alkoxy, hydroxyalkyl, amino, hydrocarbon-substituted-amino, acylamino, sulphonic, carboxylic or cyano substituents, and R1 or R2 may be a methyl, ethyl, propyl, butyl, phenyl, naphthyl or benzyl radical. Examples of the compound are 4-methyl-1:3 diphenylpyrazoline, the sodium salt of 4-methyl-3-phenyl-1-p-sulphophenylpyrazoline, the sodium salt of 4-methyl-3:5-diphenyl1-p-sulphophenylpyrazoline, 1:3:4-triphenylpyrazoline, 3-p-chlorophenyl-4-methyl-1-phenylpyrazoline, 4-benzyl-1:3-diphenylpyrazoline and 1:3 diphenyl-4-ethyl-pyrazoline. Specifications 669,590 and 669,591, [Group IV (b)], are referred to.ALSO:Fluorescent compounds for treating fibres and films have the general formula <FORM:0712764/IV (b)/1> where R1 is a substituted or unsubstituted hydrocarbon radical, R2 is hydrogen or a substituted or unsubstituted hydrocarbon radical, and Ar1 and Ar2, which may be the same or different, are each substituted or unsubstituted aryl radicals, the compound being free from substituent nitro groups and being colourless in aqueous or ethyl alcoholic solution. Ar1 may be a phenyl or naphthyl radical with hydroxy, alkoxy, hydroxyalkyl, amino, hydrocarbon-substituted amino, acylamino or halogen substituents, Ar2 may be an aromatic radical with hydrocarbon, hydroxy, alkoxy, hydroxyalkyl, amino, hydrocarbon-substituted-amino, acylamino, sulphonic, carboxylic or cyano substituents, and R1 or R2 may be a methyl, ethyl, propyl, butyl, phenyl, naphthyl or benzyl radical.  4 - Methyl - 1 : 3 - diphenylpyrazoline.-Propiophenone, dimethylamine hydrochloride and paraformaldehyde are dissolved in ethanol to which is added one drop of concentrated hydrochloric acid and the solution boiled under reflux and the ethanol removed by distillation to obtain a white crystalline mass which is treated with 10 per cent aqueous sodium carbonate and phenylhydrazine added.  4 - Methyl - 3 - phenyl - 1 - p - sulphophenylpyrazoline (sodium salt).-Propiophenone, dimethylamine hydrochloride and paraformaldehyde are dissolved in ethanol and one drop of hydrochloric acid is added.  After boiling under reflux and the ethanol removed by distillation the residue is dissolved in 10 per cent aqueous sodium carbonate and phenylhydrazine p-sulphonic acid added with heating.  4 - Methyl - 3 : 5 - diphenyl - 1 - p - sulphophenylpyrazoline (sodium salt).-Alpha-benzalpropiophenone is added to an aqueous solution of phenylhydrazine-p-sulphonic acid containing sulphuric acid.  After boiling under reflux, cooling, diluting with water, 40 per cent aqueous sodium hydroxide is added.  1 : 3 : 4-Triphenylpyrazoline.-Desoxybenzoin, paraformaldehyde and dimethylene hydrochloride are dissolved in ethanol and one drop of concentrated hydrochloric acid added, and the solution boiled under reflux with the addition of more paraformaldehyde. A solution of phenylhydrazine in 3 per cent aqueous sodium carbonate is then added and the mixture heated on a steam bath to precipitate a semi-solid mass.  3 - p - Chlorophenyl - 4 - methyl - 1 - phenylpyrazoline.-p-Chloropropiophenone, dimethylamine hydrochloride and paraformaldehyde are dissolved in ethanol, a few drops of concentrated hydrochloric acid added, and the solution refluxed after which the solution is evaporated under reduced pressure, the solid residue dissolved in ethanol, phenylhydrazine and 20 per cent aqueous sodium hydroxide and the resulting solution refluxed.  4 - Benzyl - 1 : 3 - diphenylpyrazoline.-A few drops of concentrated hydrochloric acid are added to a solution of b -phenylpropiophenone, dimethylamine hydrochloride and paraformaldehyde in ethanol, and after refluxing the solution is evaporated under reduced pressure to obtain a solid residue which is treated with aqueous sodium hydroxide, phenyl-hydrazine and ethanol and further refluxed.  1 : 3 - Diphenyl - 4 - ethylpyrazoline.-A few drops of concentrated hydrochloric acid are added to a solution in ethanol of n-butyrophenone, dimethylamine hydrochloride and paraformaldehyde.  After refluxing and evaporation under reduced pressure a solid residue is obtained which is dissolved in ethanol, phenylhydrazine and 4 per cent aqueous sodium hydroxide and the solution refluxed.  Specifications 669,590 and 669,591 are referred to.ALSO:A compound of the formula:-<FORM:0712764/IV(c)/1> where R1 is a substituted or unsubstituted hydrocarbon radical, R2 is hydrogen or a substituted or unsubstituted hydrocarbon radical, and Ar1 and Ar2, which may be the same or different, are each substituted or unsubstituted aryl radicals, the compound being free from substituent nitro groups and being colourless in aqueous or ethyl alcoholic solution, is used for imparting fluorescent whiteness to filaments, threads, yarns, fabrics of natural or artificial materials including regenerated cellulose, cellulose derivatives, vinyl resins and polyamides, paper, cardboard, felt and films of artificial materials.  The compound may be applied in a weakly acid aqueous p or an alcoholic solution, or may be included in liquid composition from which fibres and films are extruded or cast or may be included in the pulp material from which paper is formed, or may be included in coating compositions, e.g. in photographic emulsions, or for treating textiles may be used in conjunction with dyes or detergents. Ar, may be a phenyl or naphthyl radical with hydroxy, alkoxy, hydroxyalkyl, amino, hydrocarbon-substituted amino, acylamino, or halogen substituents, Ar2 may be an aromatic radical with hydrocarbon, hydroxy, alkoxy, hydroxyalkyl, amino, hydrocarbon-substituted-amino, acylamino, sulphonic, carboxylic, or cyano substituents, and R1 or R2 may be a methyl, ethyl, propyl, butyl, phenyl, naphthyl or benzyl radical.  Examples of the compound are 4-methyl-1 : 3-diphenylpyrazoline, the sodium salt of 4-methyl-3-phenyl-1-p-sulphophenylpyrazoline, the sodium salt of 4-methyl-3 : 5-diphenyl-1-p-sulphophenyl-pyrazoline, 1 : 3 : 4 - triphenylpyrazoline, 3-p-chlorophenyl-4-methyl-1-phenylpyrazoline, 4-benzyl-1 : 3-diphenyl-pyrazoline and 1 : 3 diphenyl-4-ethylpyrazoline. Compounds in which R2 or Ar2 contain a sulphonic acid substituent may be used in weakly acid or neutral aqueous or organic solutions for treating wool.  Specifications 669,590 and 669,591, [Group IV(b)], are referred to.