Patent GB-732379-A (GB)
Title: An a : a-dichloroadipic acid and the use of derivatives thereof in a process and preparations for producing prints with azo dyestuffs which are insoluble in water
Filed: 1952-10-15
Abstract: The invention comprises a printing paste consisting of (a) a diazoamino compound in which the residue not taking part in dyestuff formation contains water-solubilizing groups, (b) an azo coupling component, (c) an alkali metal salt of a ,a 1-dichloradipic acid (said acid having the melting point 176 DEG  to 178 DEG  C.), its alkyl ester or amide, (d) the customary accessories, i.e. thickening agent, caustic soda, urea, ethanol and water.  It also comprises a preparation for the manufacture of insoluble azo dyestuffs on fibres, consisting of (a) a diazoamino compound in which the residue not taking part in the dyestuff formation contains water-solubilizing groups, (b) an azo coupling component, and (c) an alkali metal salt of a ,a 1-dichloro-adipic acid (said acid having the melting point 176 DEG  to 178 DEG  C.) or its alkyl ester or amide forming such a salt by the action of caustic alkali.  The preparation of the a ,a 1-dichloradipic acid and its methyl ester is described (see Group IV (b)).  Examples describe printing pastes comprising (1) an equimolecular mixture of 1-acetoacetyl-amino-4-chloro-2,5-dimethoxybenzene and the diazoamino compound of diazotized 5-chloro-2-amino-1-methylbenzene and the sodium salt of methyl amino-ethane sulphonic acid made into a paste with urea, ethanol, caustic soda lye and hot water, to which are added wheat starch tragacanth thickener containing a ,a 1-dichloradipic acid previously neutralized with caustic soda; (2) an equimolecular mixture of 1 - (21,31 - hydroxy - naphthoylamino) - 2-ethoxy-benzene and the diazoamino compound from diazotized 2,5-dichloraniline and the sodium salt of 2-methylamino-5-sulphobenzoic acid with the other ingredients as in (1); (3) an equimolecular mixture of 1-(21,31-hydroxynaphthoyl - amino) - 2 - methoxybenzene and the diazoamino compound from diazotized 4 - chloro - 2 - amino - 1 - methoxybenzene and the sodium salt of methyl-aminoacetic acid with the other ingredients as in (1); (4) a mixture of 21,31-hydroxynaphthoylaminobenzene and the diazo-amino compound from diazotized 3 - amino - 6 - benzoylamino - 4-methoxy-1-methylbenzene and the sodium salt of methyl-aminoacetic acid, urea, alcohol, caustic soda lye and water, to which is added neutral wheat starch tragacanth thickener to which has been previously added a ,a 1-dichloradipic acid dimethyl ester and caustic soda lye; (5) an equimolecular mixture of 2,3-hydroxycarbazole - carboxylic acid - 41 - chloranilide and the diazoamino compound from diazotized 4 - chloro - 2 - amino - 1 - methoxybenzene and the sodium salt of methyl-aminoacetic acid, with the other ingredients as in (1). Reference is also made for comparison to the results obtained when using printing pastes containing monochloracetic acid in place of the a ,a 1-dichloradipic acid derivative specified in the examples.  Specification 454,869 and German Specification 640,935 are referred to.ALSO:The invention comprises a ,a 1-dichloro-adipic acid of the formula HOOC.CHCl.CH2CH2. CHCl.COOH, being a colourless crystalline substance of melting point 176 DEG  to 178 DEG  C., and its alkali metal salts.  The acid is obtained by the action of chlorine on adipic dichloride at 95 DEG  to 100 DEG  C. and saponifying the a ,a 1-dichloradipic acid dichloride produced with strong hydrochloric acid.  Reaction of the dichloride with methanol gives the corresponding dimethyl ester.  The alkali metal salts of the acid are used in printing pastes in which the amide of the above acid is also specified (see Group IV (c)). Specification 454,869 and German Specification 640,935 are referred to.