Patent GB-296310-A (GB)
Title: Manufacture of new dyestuffs
IPC: C09B45/48
Filed: 1928-08-27
Abstract: 296,310. Soc. of Chemical Industry in Basle. Aug. 27, 1927, [Convention date]. Azo dyes; triarylmethane dyes.-Dyestuffs containing chromium, obtained by chroming dvestuffs derived from triarylmethanes, are combined with azo dyestuffs containing chromium and the combination is employed to produce dyeings fast to washing, alkali, water, and light on animal fibres, particularly silk and leather. A mixture of the dyestuffs may be applied in a single bath or the dyestuffs may be applied successively in separate baths. The following examples are specified. (1) A solution in 200 parts of water of 10 parts of the chromium compound of the azo dvestuff 1 : 2-;rminonaphthod-4-sulphonic acid -$- a-na,pbthol, described in Specification 104.043, is boiled with 2 parts of the chromium compound of either Chrome Azurol S or the dvestuff ob- 'tained, by sulphonating the dyest.un' acid of example 2 of Specification 172,177, the product gives on silk from an acetic acid bath a dyeing fast to washing, alkali, water, and light, and of purer colour than is obtained with the chromed azo dyestuff alone. (2) A solution in 1000 parts of water of 50 parts of the chromium compound of the azo dyestuff 1: 2-aminona.pht.ho!-4-sulphonic acid --- a-naphthol is heated with 5 parts of the chromium compound of Eriochrome Azurol B : the product dyes animal fibres in fast pure blue tints. (3) Ordinary or weighted silk is dyed by fast pure blue tints in a hot acetic acid bath containing the chromium compound of either Chrome Azurol S or the dvestuff referred tc in example 1 above as obtained by sulphonation, together with an equal weight of the chromium compound of the azo dyestuff 1 : 2- aminonaphthol-4-sulphonic acid -5- a-naphthol. (4) Ordinary or weighted si]k is first dyed in an acetic acid bath containing 0.4 parts of the chromium compound of Chrome Azurol S, and is further dyed a fast pure blue tint. with 1.6 parts of the chromium compound of the azo dyestuff 1 : 2-amino.uaphthol-4-sulpho'nic acid -> anaphthol; alternatively, the dyeings may be in the reverse order. The Specification as open to inspection under Sect. 91 (3) (a) comprises also references to chromium compounds of diamvlmethane dyestuffs and comprises the use of the chromed di- and triarylmethane dyestuffs alone for dyeing animal fibres, and includes the following additional examples. (5) The sodium salt of Chrome Azurol S is boiled with chromium fluoride solution, and the chromed dyestuff is salted out and employed for dyeing ordinary or weighted silk in blue tints fast to 'washing, alkali, and water. (6) The siilphonated product from the dyestuff acid of example 2 of Specification 172,177 is boiled with chromium fluoride solution, and the chromed dyestuff is salted out; the product dyes silk in fast pure blue tints. (7) Box calf is dyed a fast blue in a. neutral bath containing the chromium compound of example 5 or example 6, with or without the addition of the chromium compound of the azo dyestuff 1: 2-animonaphthol-4-s'ulphonic acid # a-naphthol: alternatively the two types of chrcmed dyestuffs may be -used in successive baths. This subject-matter does not appear in the Specification as accepted.