All that glitters

Global business

The global recession has not had a major impact on demand for pigments and other colour cosmetic raw materials, which Burns says has ‘held up pretty well along with other personal care products’. In particular, China’s growing wealth, especially among middle classes, is fuelling huge growth both as a market for cosmetic sales, and as a source of home-grown ingredients and competition. Retail cosmetic sales grew at 16.9% in China in 2009, to $10.8bn, according to the National Bureau of Statistics of China. In terms of sales of special ingredients destined for cosmetics, Burns says that the impact of Chinese competition is ‘huge - but that is no different from the rest of the fine and specialty chemicals market’.

Mergers and acquisitions among specialty chemical companies are continuing and Burns suggests that there are more to come. Dow Chemical's acquisition of Rohm & Haas is to go ahead after hitting some financial difficulties earlier this year. Sun Chemical, the world's largest producer of printing inks and pigments and a major supplier of cosmetic pigments is ‘on the acquisition path’, and BASF just finished absorbing Engelhard after swallowing Ciba last year.

Back to the future

Not all the colours used today are the latest inventions – many popular since antiquity are still in demand. For instance ultramarine blue, originally derived from the precious stone, Lapis Lazuli, featured on Tutankhamun’s funeral mask, was also used to decorate the Taj Mahal. French scientist Jean Baptiste Guimet and Germany’s Christian Gmelin separately discovered synthetic routes to ultramarine in the late 1820s, prompting a wave of factories in Europe. Ultramarine’s blue colour is based on sulfur (SIII), although this is readily oxidised and so is stabilised in a protective kaolin (clay) lattice, produced by heating sulfur, clay and sodium carbonate to almost 800oC in a kiln, followed by slow cooling, oxidation and purification processes.

The synthetic pigment was particularly popular for taking a yellow tone out of white laundry during washing. James Reckitt built an ultramarine factory in Hull, UK, in 1884 to extend his range of existing laundry products. This eventually became Holliday Pigments. Still a leading supplier of ultramarine pigments today, Holliday became part of Rockwood Holdings’ Colour Pigments and Services Division in 2008. The company’s pigments are widely used in eye shadows, mascara, eyeliners, blushers, lipsticks, body and face paints. Ultramarine blue is also often utilised as a shading component in black mascaras and eyeliners.

The colour purple

Spring makeup trends often feature either bold, punchy colours or soft pastels. The mix of lighter and bright shades in 2010 is no exception. In the last two years, purples have been extremely popular – including dark, gothic-inspired lip colours, metallic effect eye shadows and deep violet nail polish. This season, however, colour picks are lightening up, towards softer lilac shades.

Dave Masterman, technical support manager for Holliday Pigments, explains the chemistry behind both the pastel and more vibrant shades of violet currently so fashionable: ‘Manganese violet (MnV) is a synthetic, inorganic pigment which was first introduced around 1900,’ he says. It is essentially a covalent combination of ammonia, manganese and phosphate. The standard chemical description is ammonium manganese pyrophosphate. ‘The chromophore which gives the pigment its bright violet colour is trivalent manganese, which is stabilised within the compound structure by strong coordination with the phosphate and ammonia ions.’

Manufacturers create Mn^V with a manganese salt slurried with di-ammonium hydrogen phosphate and some form of phosphoric acid. As well as using a very clean process, Masterman says that correct raw material selection is important, because the exact shade and purity of the MnV pigment is determined by the ratio of initial reactants and the initial source of manganese. ‘In practice, a blue-shade violet and a red-shade violet are the two ends of the Mn^V colour range,’ he says. ‘Intermediate shades can be obtained by blending these two.’

Mn^V is mainly produced for cosmetics, which account for between 70 and 80% of global production of around 200t/year. Its high demand is thanks to the red tone it achieves, and delicate tints that can be created using blends of talc.

Eyeliner, mascara and eye shadow are principal uses, while rouges, blushers, nail lacquers and toners are other products typically containing the pigment. Its high light fastness, non-migrating characteristics and stability, with good transparency and purity of shade, make it an ideal choice, and its heat stability and good dispersal characteristics should also aid manufacture.

Although unlikely to cause issues at the levels used in makeup, Environment Canada has flagged Mn^V for further attention due to its suspected aquatic toxicity and persistence.