Who's who: Colourful chemistry

Sarah Houlton marvels at the rainbow of career options available to colour chemists

The UK textile dye industry may have been having a torrid time in recent years, but that doesn’t mean there are no career options for those fascinated by colour and its chemistry. The University of Leeds has a colour science department that offers degrees in the subject, and while there may be little domestic dyestuff manufacture these days, there are still career opportunities for chemists in pigments and specialist organic colours.

’It’s easy to export finished textile products from Asia, but imports and exports of paint, for example, are only a small part of the market,’ explains Adrian Abel, who has spent his career in the pigment industry and is now a consultant for US-based Dominion Colour. ’Magazines are usually printed in the country where they are read, and a lot of packaging, particularly for food, is produced domestically too, and these all need pigments.’ 

Most opportunities for colour chemists lie in the intermediate area between pigment manufacture and the end-user. ’In paints and inks, preparation manufacturers turn the pigment powders into easy-to-use dispersions - it’s essentially a formulation business,’ Abel says. ’Organic pigments, in particular, are fairly sophisticated and can have a variety of different surface treatments, and paint manufacturers find them quite difficult to use effectively. So they usually buy them as preparations. This type of work has a high technical content, so there are certainly career opportunities for chemists here.’ 

The equivalent sector on the plastics side is known as masterbatch. ’When a coloured plastic bag is made, for example, the film manufacturer doesn’t use a selection of different pigments as powders - they will ask a masterbatch company for a formulation that will give the same colour every time it is put into a batch,’ says Abel. ’It’s not just the colour - the masterbatch will confer other properties such as antistatic, and this needs to be the same every time as well. There is definitely a market for people with chemical knowledge in this industry - it’s very much a service industry, trying to make chemicals work better and more effectively.’

From plastics to inks 

There are also opportunities in the inks market. ’While solvent-based inks are often prepared from flush pastes that are made as the organic pigment is synthesised, these have all but vanished from the UK. However, water-based inks require organic pigment dispersions and this part of the ink industry is growing,’ says Abel. 

Perhaps surprisingly, there is far less call for colour chemists within the pigment end-user industry. ’While colour plays an important role in paints, plastics and printing, chemists who go into those industries tend to have a much wider appreciation of chemistry, of which colour is just one part,’ he says. ’For example, at the big decorative paint manufacturers, I’d be surprised if there were specific colour chemists on the staff, but there are certainly paint chemists with colour knowledge.’ 

Things are a little different on the organic colour side. The commoditisation of dyestuffs and pigments has led to the majority of manufacture being shifted to Asia, leaving only the small-volume patent-protected specialist dyes, where margins are much higher - and here there is some research into novel dye molecules.  

’The areas that are thriving are niche ones, such as photochromics, medical dyes and infrared dyes that have specialist applications such as security marking,’ says Nigel Corns, safety coordinator and R&D chemist at Huddersfield, UK-based dye manufacturer James Robinson. ’We have designed molecules to allow physical and chemical characteristics to be tailored for use in different plastic substrates.’ 

There are also opportunities in developing applications - taking existing products and finding new markets for them, or new ways of applying the dyes in their current uses. ’Hair dyes are a good example,’ says Corns. ’For a permanent hair dye, two colourless molecules enter the hair through its pores, and react together there to make one large coloured molecule that can’t get out again. Our applications team will work with customers to develop specific coloured dye combinations. The colour depends on which molecules are put together - you can use mixtures of different smaller molecules to alter the shade,’ he says. ’And European hair takes up dye differently from African hair or Asian hair, which also poses problems. There are plenty of interesting areas of chemistry!’ 

Sarah Houlton is a freelance science writer based in London, UK