Patent GB-349955-A (GB)
Title: Improvements in or relating to printing on cotton by means of vat dyestuff preparations
Filed: 1929-11-30
Abstract: Printing; dye preparations; hydroxyanthraquinones.-The strength and the speed of fixation of printings on cotton with vat dyes are increased by incorporating in the printing pastes hydroxyanthraquinones or their substitution, e.g. halogen-substituted, products or reduction products thereof which still retain oxygen in the ms-position, or mixtures of compounds of these types, e.g. the technical mixture of 2 : 6- and 2 : 7-dihydroxyanthraquinones.  The further addition of anthraquinone or reduction products thereof containing oxygen is advantageous.  The hydroxyanthraquinones, anthraquinone, and reduction products thereof are employed in a finely divided state obtained for example by (1) dissolving in sulphuric acid and precipitating with water, (2) dissolving in alkali and precipitating with mineral acids, or (3) reducing in presence of p  glycerol or other organic solvents miscible with water.  An example is given of the reduction of an aqueous solution of 2-hydroxyanthraquinone in presence of glycerol by means of ammoniacal hydrosulphite to obtain a mixture of finely divided 2-hydroxyanthraquinone and reduction products thereof.  The finely divided material may be incorporated with the dyestuffs together with a hydrotropic agent and/or glycerol or other water soluble alcohol and with or without reducing agents such as sodium hydrosulphite.  Titanium salts may also be present.  The following examples are specified.  (1) The material is printed with an aqueous paste containing 6 : 61-dichloro-4 : 41-dimethyl-bis-thionaphtheneindigo, glycerol, 1-(or 2-) hydroxyanthraquinone, wheat starch, British gum powder, commercial gum, tragacanth, potash, and sodium formaldehydesulphoxylate, dried, steamed moist, developed with a mixture of potassium bichromate and acetic acid, and soaped at the boil; the dyestuff may be replaced by 6 : 61-diethoxy-2 : 21-bis-thionaphtheneindigo, the dyestuff obtainable by oxidation of naphthoxythionaphthenecarboxylic acid with alkaline potassium ferricyanide, or the dyestuff obtainable by heating 2-methyl-4-chlorophenylthioglycollic acid with strong sulphuric acid.  (2) The material is similarly printed with 2 : 7-dibromanthanthrone, 4 : 8-dianisoyl (or dibenzoyl) diamino-1 : 5-dihydroxyanthraquinone, Caledon jade green, or 5 : 51-dibenzoylamino-dianthraquinonyl-1 : 11-oxamide (cf. Specification 231,532, [Class 2 (iii), Dyes &c.], with replacement of the 1- (or 2-) hydroxyanthraquinone by anthraflavic acid.  (3) Similar printing pastes are obtained using the following vat dyestuff and hydroxyanthraquinone ingredients: (a) the dyestuff from 6-methoxy-3-hydroxythionaphthene and 4 - methyl - 6 - bromo - 2 : 3 - dihydro - 3 - ketothionaphthene-2-(p-dimethylamino) anil (cf. Specification 222,094, [Class 2 (iii), Dyes &c.], and 2-(or 4-) hydroxy-1-chloroanthraquinone or 1 : 5-dihydroxyanthraquinone, (b) the dibenzpyrenequinone obtainable by action of aluminium chloride on Bzl-benzoylbenzanthrone (cf. Specification 220,304, [Class 2 (iii), Dyes &c.],) and 2-hydroxy-1-chloroanthraquinone, (c) Flavanthrone, or the dyestuff obtainable by heating 2-methyl-4-chlorophenylthioglycollic acid with strong sulphuric acid, or Caledon jade green, and 1 : 8-dihydroxyanthraquinone. (4A) A paste is prepared by reducing with ammoniacal hydrosulphite a mixture of 6 : 61-diethoxy-2 : 21-bis-thionaphtheneindigo, anthraquinone, 2-hydroxyanthraquinone, and glycerol, incorporating the reduction product with sodium-benzenesulphonate, and concentrating. (4B) The paste in (4A) is thickened with a mixture of tragacanth, commercial gum, wheat starch, water, British gum powder, glycerol, potash, and sodium formaldehydesulphoxylate for use in printing.  (5) A paste of 4 : 8-dianisoyldiamino-1 : 5-dihydroxyanthraquinone is mixed with anthraflavic acid, glycerol, and urea, concentrated, and passed through a fine sieve; it may be converted into a printing paste as in (4B).  (6) A preparation as in (5) is obtained using as the dyestuff that of example 1 of U.S.A. Specification 1,667,848.  (7) An aqueous paste of 4 : 51-dibenzoylamino-1 : 11-dianthraquinonylaminocarbazole (cf. Specification 307,306, [Class 2 (iii), Dyes &c.],) is mixed with glycerol and an aqueous preparation containing anthraflavic acid and its reduction products with or without urea or other hydrotropic agent such as sodium dimethylmetanilate, sodium naphthalene-b -sulphonate, or mixtures thereof, and the mixture is concentrated and passed through a fine sieve; it may be mixed with the usual ingredients to form a printing paste.  (8) An aqueous paste of dibrompyranthrone (cf. Specification 12568/09, [Class 2 (iii), Dyes &c.],) is mixed with glycerol and the disodium salt of anthraflavic acid with or without urea or other hydrotropic agent such as sodium benzenesulphonate, sodium dimethyl-sulphanilate, sodium naphthalene-a -(or b -)-sulphonate, or sodium tetrahydronaphthalene-b -sulphonate (cf. Specification 148,408, [Class 2 (iii), Dyes &c.],) and the mixture is concentrated.  (9) An aqueous paste of 6 : 61-diethoxy-2 : 21-bis-thionaphtheneindigo is mixed with anthraflavic acid and glycerol and the mixture is reduced with ammoniacal hydrosulphite, sodium benzenesulphonate is added, and the mixture is concentrated; it may be converted into a printing paste as in (4B); the dyestuff may be replaced by 6 : 61-dichloro-4 : 41-dimethyl-bis-thionaphtheneindigo with addition of phthalic acid or its anhydride as hydrotropic agent; these preparations are also applicable in slop padding processes.  Reference has been directed by the Comptroller to Specification 3241/11, [Class 2 (iii), Dyes, &c.].