Patent GB-1014651-A (GB)
Title: Process for optically brightening natural or synthetic polymeric materials
IPC: D06L3/12
Filed: 1961-11-13
Abstract: Synthetic polymeric matezials, e.g. nitrile polymers, polyvinyl esters, polyvinyl acetals, polymers and copolymers of acrylic acid esters, polyacrylamides, polyesters, polyamides or polyurethanes, to be used in the production of artificial fibres and films, or as coating compositions, are optically brightened by incorporating therein a salt of a 1 : 2-pyrroline which is arylated in the 2-position and contains two alkyl ether groups bound in the para position relatively to each other to the aryl nucleus bound to the heterocyclic ring, one of the ether groups being bound in ortho position relatively to the carbon atom of the heterocyclic ring. 1 : 2 pyrrolines formed by the reaction of g -amino butyric, g -amino-d -methyl-valeric or g -phenyl-g -aminobutyric acid with hydroquinone dimethyl ether, methyl ethyl ether or diethyl ether toluhydroquinone dimethyl ether tert-buty - hydroquinone dimethyl ether, 2-chloro-, 2-bromo or 2-fluoro-hydroquinone dimethylether, succinimido - hydroquinone dimethyl ether, 2 : 5-dimethoxy phenylhydrocinnamic acid methyl ester, hydroxyhydroquinone trimethyl ether or triethyl ether, hydroquinone methyl [b -diethylaminoethyl] ether, 1 : 4 - dimethoxy - naphthalene, 2 : 5 - dimethoxy - diphenyl or 2 : 5 - dimethoxyterphenyl, in the form of their salts with hydrogen chloride, hydrogen bromide or perchloric formic, benzoic, ortho chloro benzoic, dichloracetic, difluorochloracetic, trifluoroacetic, alkyl - aryl - phosphonic, alkyl sulphuric or alkyl- or aralkyl-sulphonic acids may be used, e.g. the salt of the pyrroline of formula <FORM:1014651/C3/1>ALSO:Paper, including photographic paper, and fibrous materials made from natural or synthetic polymeric materials are optically brightened by treating them with a salt of 1 : 2-pyrroline which is arylated in the 2-position and contains two alkyl ether groups bound in the para position relatively to each other to the aryl nucleus bound to the heterocyclic ring, one of the ether groups being bound in orthoposition relatively to the carbon atom of the aryl nucleus bound to the 2-carbon atom of the heterocyclic ring. The fibrous materials may be woven or knitted fabrics, felts, fleeces or ribbons made from nitrile polymers, cellulose esters or ethers, polyvinyl esters, polyvinyl acetals, polymers and copolymers of acrylic acid esters, polyacrylamides, polyesters, polyamides, polyurethane, silk, cotton or regenerated cellulose. Fibrous materials containing acid groups bound to the constitutents of the fibrous substance, e.g. cellulose acetate fibres containing a resin containing carboxylic acid groups, e.g. copolymers of maleic anhydride and/or maleic acid with vinyl methyl ether, vinyl ethyl ether or vinyl acetate, polyacrylonitrile fibres containing itaconic or acrylic acid or in which sulphonic acid groups have been formed by the oxidation of sulphur containing substituents and polyester fibres of terephthalic acid with glycols into which sulphuric acid groups have been introduced by the action of a sulphonating agent or into which carboxyl groups are incorporated at a high temperature by the action of a chemically reactive substance, may be treated with the free 1 : 2-pyrrolines so that the salts are formed on the fibrous materials.  1 : 2-pyrrolines formed by the reaction of g -amino butyric, g -amino-d -methyl-valeric acid or g phenyl-g -amino butyric acid with hydroquinone dimethyl ether, methyl ethyl ether or diethyl ether, toluhydroquinone dimethyl ether, tert-butyl-hydroquinone dimethyl ether, 2-chloro, 2-bromo or 2-fluoro-hydroquinone dimenthyl ether, succinimido-hydroquinone dimethyl ether, 2 : 5 dimethoxy phenyl-hydrocinnamic acid methyl ester, hydroxyhydroquinone trimethyl ether or triethyl ether, hydroquinone methyl [b -diethylamino-ethyl] ether, 1 : 4 dimethoxy-naphthalene, 2 : 5-dimethoxy-diphenyl or 2 : 5-dimethoxy-terphenyl, in the form of their salts with hydrogen chloride, hydrogen bromide or perchloric, formic, benzoic, ortho-chloro benzoic, dichloracetic difluorochloracetic, trifluoroacetic, alkyl-arylphosphonic, alkyl sulphuric or alkyl-or aralkyl-sulphonic acids, may be used.  Hydrophobic fibres may be treated with a weakly alkaline solution or dispersion of the 1 : 2 pyrroline and the brightening effect developed by after-treatment with an acid.  The brightening agent may be applied as a solution or dispersion in water or an organic solvent, which may also contain a dyestuff and a thickening agent, by padding, spraying or printing and then steaming or drying at a moderate or higher temperature, and may be carried out in conjunction with bleaching with a chlorite solution.