Patent GB-547411-A (GB)
Title: Improvements in or relating to the manufacture of organic colouring materials
IPC: C09B67/14
Filed: 1941-02-24
Abstract: 547,411. Dyes. DU PONT DE NEMOURS & CO., E.I. Feb. 24, 1941, No. 2473. Convention date, Feb. 23, 1940. [Class 2 (iii)] Water-insoluble organic colouring matters, e.g. phthalocyanines or vat dyestuffs, are obtained in a finely subdivided form, showing improved brilliance and tinctorial strength, by introducing a solution thereof in acid into an aqueous fluid in a state of turbulent flow, i.e. flowing at a velocity greater than the critical velocity at which eddy currents are set up. Specified acids used are oleum, sulphuric, chlorosulphonic, ethylsulphonic, phosphoric and p-toluenesulphonic acids. In examples, (1) a solution of N:N<SP>1</SP>-diethyl-2:2<SP>1</SP>-dipyrazolanthronyl in conc. sulphuric acid is introduced by a small central pipe and in the direction of flow into water at 25-30‹C. flowing at above the critical velocity through a constricted tube and the precipitate is filtered off, washed free of acid and dried; (2) a solution of monochlorinated indanthrone in conc. sulphuric acid is introduced downwards through a small central pipe into water at 77-82‹C. in turbulent downward flow as it leaves a constriction near the lower end of a wider tube and the precipitate is treated as in (1); (3) a solution of flavanthrone in conc. sulphuric acid is treated as in (1), the acid-free filter cake being purified by treatment with an aqueous solution of sodium hypochlorite, washed and dried ; (4) a solution of indanthrone in conc. sulphuric acid is introduced into water at 80-90‹C. flowing as in (1) and further treated as in (3) ; (5) and (6) a solution of copper phthalocyanine (cf. Specification 410,814) in conc. sulphuric acid is introduced into water at (5) 25-30‹C., (6) 95-100‹C. flowing as in (1), the acid-free filter cake being re-slurried with an aqueous ammonia solution, filtered, washed and dried ; (7) and (8) a solution of (7) Sulphanthrene orange R, (8) Sulphanthrene red 3B, in sulphuric acid monohydrate is introduced into water at 90-95‹C. flowing as in (1) ; (9) a solution of copper phthalocyanine in conc. sulphuric acid is introduced into an impeller pump at 25-30‹C. and the precipitate is treated as in (1); (10) a solution of 2:1-naphththioindigo in conc. sulphuric acid at 5‹C. is introduced into water at 3-5‹C. flowing as in (1) ; (11) a solution of Bz- 3-Bz-4-dichloroanthraquinone-2:1-(N)-benzacridone in conc. sulphuric acid is introduced into water at 90-92‹C. flowing as in (1) and the acid-free filter cake is thinned with a condensation product of formaldehyde with naphthalene sulphonic acid and incorporated in emulsion printing inks ; (12) a solution of disodium phthalocyanine (cf. Specification 410,814) in conc. sulphuric acid is introduced into water at 25-30‹C. flowing as in (1) ; (13) a solution of aluminium phthalocyanine in conc. sulphuric acid is treated as in (1); (14) a solution of copper phthalocyanine in anhydrous phosphoric acid is introduced into water at 95-100‹C. flowing as in (1) ; (15) a solution of hexadecachloro-copper phthalocyanine (cf. Specification 478,256) in a mixture of sulphuric acid monohydrate and chlorosulphuric acid is treated as in (1) ; (16) a solution in conc. sulphuric acid of crude copper phthalocyanine containing anhydrous sodium sulphate is introduced co-axially into water at 95-98‹C. in a state of turbulent flow through a pipe.