JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (3) That [•-hydroxy naphthoic acid will form an anilide and substituted anilides--this reaction placed over twenty new intermediates in the hands of the pigment chemist and enabled various "tailor-made" pig- ments to be prepared. The following formulae illustrate the points made. (1) All the yellow and orange pigment dyestuffs com- mercially available use, not a naph- thol, but either a derivative of aceto acetic acid or a substituted pyro- zalone as second component. Thus if diazotised m-nitro-p-toluidine is coupled with [•-naphthol, the well- known Itelio Fast Red RL results, as was mentioned earlier. If, however, the same diazotised amine is coupled with aceto acer anilide the equally well-known Hansa Yellow G results. CH• CH• NH•+.O.N.OH N--N.C1 +Hcl q- CHq. CO. CH,,. CO. CH. CH• •l XNO, N N CH •.CO.CH.CO.CH.NIt./ Variations on this basic formula involving other amines and/or sub- stituted anilides enables a compre- hensive range of yellow pigments to be prepared. (2) If, now, the amine above is substituted by the diamine 3:3 dichlor benzidine, the product known as E. enzidine Yellow results. This product, although inferior to the Hansa Yellow G noted above in respect of fastness to light and clean- liness of colour, possesses very much greater staining power and also increased resistance to the action of solvents. (3) The utility of the substituted anilides of [•-hydroxy naphthoic acid is, perhaps, as well illustrated by consideration of the following two maroon pigments as any other example. Coupling di•zotised m- nitro-p-toluidine with the m-nitro anilide of [•-hydroxy naphthoic acid, gives a deep maroon pigment with a very yellow, somewhat unattractive undertone. If, conversely, the o- toluidide is used, a rather paler maroon with a pleasing blue under- tone is obtained. It will be obvious that, with some twelve or more com- mercially available amines and dia- mines and twenty or more second components, the range of pigment dyestuffs is very large. The varia- tion in such physical properties as temperature concentration, acidity or alkalinity will affect the properties of the resulting pigments'as also w/11 the presence of surface-active agents or the deliberate addition of small quantities of other amines or naphthols. 148

PIGMENTS Generally speaking, the pigment dyestuffs commercially available pos- sess high tinting strength and very good fastness to light coupled with good to very good fastness to acid and alkali, but with some tendency to bleed in oil and waxes. It is not proposed in this paper to discuss black pigments, since it is believed that the present company will have adequate information about these from their manu- facturers. In closing, I would like to express my sense of the honour you have conferred upon me by inviting me to address you and hope that the talk has been of some use to you all, and, finally, to express my gratitude to the directors of Lewis Berger (Great Britain) Ltd., for permission to give this talk. ADVERTISERS IN THIS ISSUE page STAFFORD ALLEN & SONS, LTD. Wharf l•oad, London, N. 1 ................... Cover iv A BOAKE, I-•OBERTS 8½ GO., LTD. Carpenters l•oad, London, E. 15 ... 140 BRITISH INDUSTRIAL SOLVENTS (A Division of the Distillers Co., Ltd.) 4 Carendish Square, London, \V.1. 134 W. J. BUSH & Co., LTD. Ash Grove, London, E.8. ... Cover iii ANTOINE CHIRIS, LTD. Bridge House, Tadworth, Surrey ... 136 CRODA, LTD. Croda House, Snaith, Goole, Yorks .... ... 242 FIELD & CO. (AROMATICS), L•D. Stonefield Close, l•uislip, Middlesex .................. 243 FIRMENICH 8½ Co., LTD. 414 London [Road, Isleworth, Middlesex ............ Cover ii GIVAIID-kN 8½ Co., LTD. Whyteleafe, Surrey ... 135 HOWARDS OF ILFORD, LTD. Ilford, Essex ...... ... 133 •/[ARCHON PRODUCTS, LTD. Whitehaven, Cumberland ... 137 IN'IPA LABORATORIES, LTD. See under P. Samuelson •_• Co. POLAK • SCHWARZ (ENGLAND), LTD. 50 Great Cambridge l•oad, Enfield, Middlesex ............ RONSHEIM & MOORE (Proprietors: The Gardinol Chemical Co., Ltd.) Grosvenor Gardens House, London, S.W.1 ............... P. SAMUELSON & Co. l•oman Wall House, 1 Crutched Friars, London, E.C.3 ... SSFLOR, LTD. •radsworth l•oad, Perivale, Greenford, Middlesex 138 239 244 241 149