High performance pigments can enhance the performance properties of printing ink.
(Photo courtesy of Clariant)
Why risk tinkering with something that works when there’s the chance things could get worse, not better? Printing ink manufacturers have relied on classical pigments to give their products a wide range of color choices and good performance properties. But now pigment suppliers are expanding their high performance (HP) pigment offerings – by which they are offering ink manufacturers a way to improve performance and possibly develop better ink.
“While not a strong market in the ink industry, HP pigments play an important part in the printing industry for special uses requiring light, heat and chemical resistance,” said David Dugan, marketing manager, BU ink pigments, Clariant Corporation.
HP pigments can improve performance properties such as lightfastness, color strength, heat and chemical stability, weatherfastness and solubility. According to Dr. Alexander Sieber, head of business unit, ink pigments, for Clariant GmbH, four applications driving growth of HP pigments are outdoor advertising, security printing, decorative laminate printing and flexible food packaging.
Industrial printing applications, such as products exposed to the outdoors, is another area where demand for HP pigments has increased. “The inks used in these applications require pigments with higher performance properties than conventional pigments for lightfastness, in particular, but also for chemical resistance,” said Roland Valin, manager, sales and technical marketing appearance and performance technologies, Engelhard Corporation. “As demand for these applications increases, so does demand for high performance pigments.”
“There has always been some demand for HP pigments for long-life printed articles such as PVC floor and wallcoverings, decorative laminates, outdoor advertisements, traffic signs and security papers,” said Hanspeter Hauser, coating effects segment, business line imaging and inks, Ciba Specialty Chemicals. “During the last 20 years, demand has steadily increased for HP pigments for short-life printed substrates too, especially in the food packaging sector.
“The HP pigment trend for food packaging applications is driven by increasingly high standards in terms of environmental acceptability, purity and resistance,” continued Mr. Hauser. “No migration or bleeding into the packaging and from there into the foodstuff is a must today. Another fact is the quicker manufacturing process in food packaging production today. Higher heat seal and curing temperatures (up to 360°C) make it essential to use HP pigments for this application.”
Among Clariant’s new introductions to the HP market is 11-3029 Hostaperm Yellow H5G, a pigment yellow 213 offering outstanding lightfastness; 11-4002 Novoperm Yellow P-M3R, pigment yellow 139 designed for solvent-based flexo inks; and 11-4022, Hostaperm Violet P-RL, a pigment violet 23 designed for UV flexo inks. Mr. Dugan also said additional HP pigments will be introduced in the future.
Ciba recently introduced Cromphtal Magenta ST, which the company said is the first real HP process magenta pigment for inks. “It is highly transparent and glossy, readily dispersible and fulfills the highest durability requirements,” said Mr. Hauser.
New from EM Industries for printing ink applications are Bi-Flair pigment dispersions. According to the company, these are suspensions of finely crystalline bismuth oxychloride pigments that are available in a number of ink, coatings and polymer resin bases.
Yellow pigments on a filter press, which is one part of the drying procedure.
(Photo courtesy of Clariant)
Since ink jet continues to be one of the fastest growing technologies in the ink industry, it is no surprise that suppliers report the strongest growth rates for HP pigments are seen in this market.
“The demand for high performance pigments is greater in the ink jet and in the toner area for the new digital presses where the increased cost of the high performance pigment can be included in the price of the ink or toner and price is less of an issue,” said Maurice Carruthers, general manager, Sun Chemical’s North American business unit.
“Ink jet, for example, has been used increasingly on billboards and, as a result, will require increasing quantities of high performance pigments,” said Mr. Valin.
HP Versus Conventional Pigments
If HP pigments can enhance an ink’s performance properties, why haven’t they been adopted by more ink manufactures? The main reason – cost. Mr. Carruthers estimated the price for a pound of conventional red 57.1 to be $4, compared to $26 for one pound of high performance red 122.
“Conventional pigments, or rather classical pigments, are low cost products which are normally well-designed and optimized for the relevant applications,” said Dr. Sieber. “In other words, they are cheaper and often easier to use than HP pigments.”
“Some high performance pigments are very difficult to disperse, especially in the magenta types, and the yellows tend to be coloristically weaker than the conventional Azo yellows, requiring higher pigment loads which lead to ink formulation problems,” said Mr. Carruthers.
“Conventional pigments have a long history of use in the printing ink industry; they are simpler molecules, so they cost less and tend to be easier to disperse,” said Mr. Valin. “However they do not always offer the performance properties necessary for industrial applications.”
There are some instances when HP pigments should be strongly considered as a better alternative because of their enhanced performance properties. “The structure of the pigment molecule will determine how well it weathers, but other factors such as solubility, lightfastness, weatherfastness and heat and chemical stability also help determine whether a conventional pigment can be used or if a high performance pigment must be used,” said Mr. Valin.
“The use of HP pigments is essential if certain stability or fastness requirements have to be met, like heat or retort stability, light-, weather- or solventfastness,” concluded Dr. Sieber.
Speakers Sought for
Intertech’s 2002 HPP Conference
Intertech’s annual international colorants conference, High Performance Pigments 2002, will be held Jan. 21-23 at the Delray Beach Marriott, Delray Beach, FL. Hugh Smith, senior staff consultant at Sun Chemical Corporation, will serve as conference chairman.
The conference will include an overview of the latest technologies and emerging markets for high performance pigments. Topics to be covered include market trends by region and sector, new pigment technologies, international regulatory issues and trends in end-use markets with significant near-term growth.
Intertech is still in need of speakers for the conference. For more information on the conference or to submit a topic for consideration, contact Scott Stephenson, Intertech, 19 Northbrook Drive, Portland, ME, 04105; Tel. (207) 781-9808; Fax: (207) 781-2150; E-mail: email@example.com; or Web: www.intertechusa.com.