Patent GB-890519-A (GB)
Title: Process for the manufacture of coloured materials of high molecular weight
IPC: C08G18/71
Filed: 1959-02-04
Abstract: In a process for the manufacture of coloured polyurethanes by the polyaddition of an aromatic polyisocyanate with a polyhydroxylated aliphatic compound, or of coloured polyesters by the polymerization of a mixture of styrene with a condensation product of an unsaturated polycarboxylic acid and a polyhydroxyl compound, there is added before or during the polyaddition or polymerization a dyestuff which contains an isocyanate group and is free from groups imparting solubility in water.  The dyestuffs may contain substituents such as halogen atoms or alkyl, alkoxy, nitro or carbalkoxy groups. Dyestuffs of the anthraquinone and benzene-azo-benzene, benzene-azo-pyrazolone, benzene-azo-acetoacetic acid arylide and benzene-azo-naphthalene series are mentioned.  They may be added in admixture with benzene, toluene or nitrobenzene.  The coloured materials obtained, if brought into a finely-divided form, are useful as pigments.  In Examples (1) an adipic acid-glycol polyester, 2,4- and 2,6-tolylene diisocyanates and a toluene solution of azobenzene-4-isocyanate are mixed.  There is then added a mixture of water, polyglycol ether and ethylmorpholine, a yellow polyurethane foam being obtained.  A similar product was obtained using benzene-azo-naphthylisocyanate-(1:4) as dyestuff. p-Acetylamino-azo-benzene was used in a comparison experiment; (2) a plate is cast from a mixture of an unsaturated polyester from maleic acid and glycols, styrene, and a azobenzene-4-isocyanate and hardened at 100 DEG C. Benzene-azo-naphthylisocyanate-(1:4) can be used similarly; (3) a lacquer is prepared from the polyester specified in Example (1), toluene 2:4-and 2:6-diisocyanates and benzene-azo-naphthylisocyanate-(1:4) in toluene.ALSO:Azo dyestuffs containing an isocyanate group and free from groups importing water-solubility can be obtained by heating the hydrochloride of the appropriate dyestuff containing an amino group with phosgene in an inert solvent or by condensing equimolecular proportions of a monoamino dyestuff and of a diisocyanate.  The dyestuffs may contain halogen atoms or alkyl alkoxy nitro or carbalkoxy groups.  By the first method are prepared azobenzene-4-isocyanate benzene-azo-naphthyl-isocyanate-(1 : 4) and dyestuffs of the formulae <FORM:0890519/IV (c)/1> By the second method a dyestuff is prepared by reacting p-aminobenzene and 2,4-tolylene diisocyanate.  Reference is also made to benzeneazo-pyrazolone and benzene-azo-acetoacetic acid arylide dyestuffs containing NCO groups.  The dyestuffs are used for preparing coloured polyurethanes and polyesters, which, finely divided, are useful as pigments.ALSO:In a process for the manufacture of coloured polyurethanes (including foams) by the reaction of an aromatic polyisocyanate with a polyhydrooxylated aliphatic compound, there is added before or during the reaction a dyestuff which contains an isocyanate group and is free from groups imparting solubility in water.  The dyestuffs may contain substituents such as halogen atoms or alkyl, alkoxy, nitro or carbalkoxy groups. Dyestuffs of the anthraquinone and benzene-azo-benzene, benzene-azo-pyrazolone, benzene-azo-acetoacetic acid arylide and benzene-azo-naphthalene series are mentioned.  They may be added in admixture with benzene, toluene or nitrobenzene.  In Example 1,1 a yellow foamed polyurethane is obtained by reacting an adipic acid-glycol polyester, 2,4-and 2,6-tolylene diisocyanates, a toluene solution of azobenzene-4-isocyanate and a mixture of water, polyglycol ether and N-ethyl morpholine. Benzene-azo-naphthyl isocyanate-(1 : 4) can also be used as the dyestuff p-acetylamino-azo-benzene is used in a comparison experiment.