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Materials

Making The Most Of Changes In Printing

New pigment chemistry is a boon for Cabot and a Massachusetts town

September 26, 2011 | A version of this story appeared in Volume 89, Issue 39

Ink Enabler
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Credit: Cabot Corp.
Cabot is expanding this pigments facility in Haverhill, Mass.
A picture of Cabot Corp.’s inkjet dispersions plant in Haverhill, Mass.
Credit: Cabot Corp.
Cabot is expanding this pigments facility in Haverhill, Mass.

It’s been years since the old industrial town of Haverhill, Mass., could be called an economic engine. But the millions of dollars being spent there by Cabot Corp. are a sign that innovative chemistry can spur investment and create new jobs in the unlikeliest of places.

Last month, Cabot announced plans to invest $10 million to double color dispersion capacity at its ink-jet printing colorants plant in Haverhill. Powered with chemistry invented by Cabot researcher James A. Belmont, the facility makes pigment dispersions that are helping usher in big changes in the home, office, and commercial printing markets.

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Credit: Cabot
Flasks of Cabot Corp.’s pigment dispersions for ink-jet printer cartridges.
Credit: Cabot

The Haverhill plant opened in 2001 in a former backpack factory. Today it employs close to 80 lab technicians, engineers, managers, and hourly workers. The expansion project should add another 15 full-time positions, says Fred von Gottberg, who heads both Cabot’s ink-jet business and its new business segment.

Gottberg attributes the genesis of the ink-jet business to the inventiveness of the firm’s employees and their ability to see connections between seemingly disparate markets. In just a decade, they have created a business with sales approaching $70 million per year and the potential to reap much more.

Although the concept of ink-jet printing has been around since the 19th century, the practice didn’t take off until the late 1980s when ink-jet printers became popular companions to home computers. The first models printed only in black using inks made with black azo dyes. The inks were cheap and easy to formulate, but they would bleed into low-quality paper and tended to fade with time.

In the early 1990s, printer manufacturers started looking to reformulate their inks with pigments. Compared with dyes, pigments provide high color strength and image permanence. The technical challenge was creating stable dispersions of an insoluble material that could be evenly sprayed through tiny ink jets and then agglomerate on paper.

One obvious pigment candidate was carbon black. An abrasive manufactured mainly for tires and other rubber applications, carbon black was already being used in toners and other pigmenting applications. As the world’s largest producer of carbon black, Cabot was interested in the ink-jet market. But a salesperson calling on an ink manufacturer learned of a problem: Carbon black is hydrophobic and wouldn’t disperse well in the waterborne formula the ink firm was developing.

It happened that back at Cabot’s research labs in Billerica, Mass., Belmont and his colleagues had been experimenting with the surface modification of carbon black to improve its interaction with rubber in tire applications. In 1993 he discovered that reacting carbon black with diazonium salts is a versatile way to attach all kinds of functional groups to its surface.

Aware of the invention, the salesperson contacted the research group to learn whether the new surface modification technology could solve the ink maker’s dilemma. Belmont and his team confirmed that attaching one end of a diazonium salt to carbon black and the other to the right functional group did indeed improve solubility. The Cabot researchers were later successful in expanding the diazonium treatment to most of the common color pigments as well.

Von Gottberg, who joined the firm in 1997 as a chemical engineer in the ink-jet group, says Cabot executives decided to place a bet on the new technology. The Boston-based company had for years been diversifying beyond its core business of carbon black for tires, and ink-jet colorants looked like another way to do that.

They began to search for a manufacturing site that was in the vicinity of the Billerica labs. “We wanted it to be far enough away so the R&D people don’t meddle too much, but close enough that R&D people can help,” von Gottberg says.

They settled on Haverhill, which was founded in 1640 on the Merrimack River in northeastern Massachusetts. From the water-powered sawmills built in its early days to the tanneries and shoe factories that sprung up in later years, Haverhill had a long history as a manufacturing center. By the 1990s, though, many of the region’s plants had closed or were closing.

As a result, Cabot readily found experienced people eager to work. Jim Makuc, acting manager of the Haverhill plant, says most of Cabot’s Haverhill staffers once worked at nearby chemical companies such as Hampshire Chemical and Eastman Kodak that had left the area or shut down. “We found their experience around batch operations to be what we needed,” he says.

Cabot began commercial production of black pigment dispersions based on its diazonium chemistry in 1998, von Gottberg says. Color products followed around 2000. In 2001, the company moved the operation into its current building, a former Eastpak backpack sewing plant.

The company began selling its surface-modified pigments into an evolving consumer ink-jet printing market. Makers of black inks were the first to change from dyes to pigments. Today, von Gottberg says, the switch is pretty much complete, with the exception of some black ink-jet inks intended for printing photos.

The color ink-jet market has been slower to change. Overall, von Gottberg figures that roughly 60% of inks are now made with pigments: carbon black for black, phthalocyanines for cyan, quinacridones for magenta, and azos for yellow. Although printer makers don’t disclose details about their products, company literature makes clear that inks such as Epson’s DuraBrite and Lexmark’s Evercolor are made with pigments that have been functionalized to improve their durability.

Cabot has plenty of competition in the home printer pigment market, but von Gottberg claims that it is the leader in dispersions and the predominant company practicing reactive surface modification. Other ink firms, such as DuPont, tend to disperse their pigments with polymers or polyelectrolytes that are associated by physical adsorption. “In contrast, we attach our molecules to the surface,” von Gottberg says.

Having made a home in consumer printer pigments, Cabot is now looking to bigger pastures. The consumer market is tiny compared to office and, especially, commercial printing, notes Marco Boer, senior analyst at I.T. Strategies, a consulting firm that follows the digital printing industry.

Von Gottberg believes the time is right for commercial ink-jet printing. Given the proliferation of e-readers and iPads plus the move to paperless bills and bank statements, the traditional printing industry is in decline. But the same trends have created an opening for customized short-run commercial printing with ink-jet techniques.

“Instead of printing hundreds of thousands of books, you print only a few books and then print them on demand when the consumer wants to buy more,” he explains. “Financial companies are making bank statements and retirement statements more informational to the individual.”

Although commercial printing is still based largely on traditional offset lithography, the opportunity for ink-jet is huge. According to Boer, only about 500 commercial ink-jet printers operate in the world today, but these machines, which spray billions of droplets of ink at a time onto large sheets of paper, are being added at a rate of 200 or more per year.

“It’s truly an incredible opportunity,” Boer says. “There are not many markets where you can get triple-digit growth.”

For ink manufacturers, the growth rates aren’t that high, but they are healthy. Ink-jet colorant sales in the first nine months of Cabot’s 2011 fiscal year were $50 million, up from $43 million in the nine months of the previous year.

It’s in anticipation of more such growth that Cabot is expanding the Haverhill plant. Makuc says the project is taking place in two phases. The first, which doubles the capability to attach small molecules to color pigments, will be completed in November. The second and larger project will double the firm’s ability to attach polymers to pigments, typically using reactive functional groups as a bridge. It should be complete by the second quarter of 2012.

R&D into new pigment chemistry continues as well. In 2007, for example, the firm launched ink-jet colorants based on calcium-binding technology invented by Belmont and his team. As von Gottberg explains, the researchers set out to create a pigment that is evenly dispersed while in the ink cartridge and printhead but that quickly agglomerates once it hits the surface of the paper. They found the solution in calcium ions, which are present in almost all papers.

“They designed a group on the pigment that, when it sees calcium, says, ‘Okay, time to switch off,’ ” von Gottberg explains. Rather than soaking into the paper, the pigment agglomerates on top, he says, yielding high optical density.

Today, Cabot ink-jet researchers are looking for agglomeration triggers that are present in media other than paper. Specialized carbon black particles and diazonium chemistry that works with a few uncooperative pigments are also on their to-do list.

But while Cabot continues to expand its palette of surface-treated pigments, it has resisted the temptation to move downstream into formulated inks as many of its competitors have. That focused approach makes sense to I.T. Strategies’ Boer. After all, he says, “if you control the dispersion, you control the entire value chain.” ◾

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