Patent GB-827745-A (GB)
Title: Process for producing synthetic polyamides and polyurethanes of improved brightness
IPC: C08G69/42
Filed: 1956-08-09
Abstract: Mono- and bis-(naphtho triazolyl) compounds are made by oxidizing with ammoniacal copper sulphate the azo dyestuffs prepared by: (a) reducing 4-nitro-2-cyanostilbene to 4-amino-2-cyanostilbene which is diazotized and combined with 3-carboxy-2-aminonaphthalene-6-sulphinic acid; (b) reacting 2-methyl-5-nitrophenyl sulphone with benzaldehyde to form 4-nitrostilbyl-(2)-methyl sulphone which is reduced to the corresponding amino compound, diazotized and combined with 3-carboxy-2-aminonaphthalene-6-sulphonic acid; (c) combining tetrazotized 4,41-diaminostilbene-2,21-dicarboxylic acid with 2-naphthylamine-5-sulphonic acid; (d) and (e) diazotizing 4-nitro-aniline, and reacting with 3 - carboxy - 2 - amino - naphthalene - 6 - sulphonic acid to form a product which is oxidized with ammoniacal copper sulphate solution to 61 - sulpho - 3 - carboxynaphtho - (11,21,4,5)-triazolyl-4-nitrobenzene, reduced with iron and acetic acid, diazotized and combined with (d) 3-carboxy-2-aminonaphthalene-6-sulphonic acid; (e) 2-amino-naphthalene-6-sulphonic acid; and (f) tetrazotizing benzidine and combining the product with 3-carboxy naphthalene - 2 - aminosulphonic acid.  Specifications 729,584 and 788,521, [both in Group IV (a)], are referred to.ALSO:Azo-stilbene and amino azo compounds are made by (a) reducing 4-nitro-2-cyanostilbene to 4-amino-2-cyanostilbene which is diazotized and combined with 3-carboxy-2-aminonaphthalene-6-sulphonic acid, (b) reacting 2-methyl-5-nitrophenylsulphone with benzaldehyde to form 4-nitro-stilbyl-(2)-methyl sulphone which is reduced to the corresponding amino compound, diazotized and combined with 3-carboxy-2-aminonaphthalene-6-sulphonic acid, (c) combining tetrazotized 4,41-diaminostilbene-2,21-dicarboxylic acid with 2-naphthylamine-5-sulphonic acid, (d) and (e) diazotizing 4-nitroaniline and reacting with 3-carboxy-2-aminonaphthalene-6-sulphonic acid, to form a product which is oxidized with ammoniacal copper sulphate solution to 6-sulpho-3-carboxy naphtho(11,21;4,5) - triazolyl - 4 - nitrobenzene, reduced with iron and acetic acid, diazotized and combined with (d) 3-carboxy-2-aminonaphthalene6-sulphonic acid, (e) 2-amino-naphthalene-6-sulphonic acid, and (f) tetrazotizing benzidine and combining the product with 3-carboxynaphthalene - 2 - amino - 6 - sulphonic acid.  Specifications 729,584 and 788,521, [both in Group IV (a)], are referred to.ALSO:Synthetic polyamides and polyurethanes are made in the presence of optical brightening agents capable of combining chemically with the polymers under the conditions prevailing in the production of the polymers.  Specified brightening agents are:- <FORM:0827745/IV (a)/1> Pigments may also be present in the reaction mixtures.  In the examples, e -caprolactam, titanium dioxide and water are heated with (1) acetic acid and brightening agent (a); (2) brightening agents (b) and (c); (5) acetic acid and brightening agents (d) and (e); (6) acetic acid and brightening agent (f): whilst in Example (3), hexamethylene diammonium adipate, titanium dioxide, acetic acid, brightening agent (c) and water and, in Example (4), butane-diol-1,4 hexamethylene diisocyanate, titanium dioxide, and brightening agent (c) are reacted.  The products being (1) and (5) worked up into shreds, filaments, fibres, bristles or injection mouldings, (2) cast into filaments, shredded and intimately mixed with preformed poly e -caprolactam, and (4) worked up into filaments or fibres.  Specifications 729,584 and 788,521 are referred to.