Form and Function

By Christine Esposito | August 11, 2005

Formulators can create paint that performs and pleases when incorporating high performance and special effect pigments.

Coatings have two main requirements: protect the surface underneath and enhance the quality of the overall product. Today's high performance and special effect pigments have allowed formulators to create coatings that are built to last and turn heads in a variety of markets.

Forget the boring black cell phone, putty CPU and even the plain white plane. From consumer electronics to aerospace (see page 26 in this issue), unique and durable finishes are in demand as OEMs look to give their products an edge in the marketplace.

Nowhere else is this more apparent and essential than the auto industry. Here, the role of high performance and effect pigments is synergistic. Customers want form and function when it comes to auto paint.

Today's auto market requires eye-catching finishes that can withstand the punishing effects of weather, harsh chemicals, gasoline, dirt, flying debris and the local car wash. After all, this isn't a $9 cotton t-shirt that will be thrown away at the end of the season; it's a $29,000 four-door sedan sporting a seven-year, 100,000 mile warranty.

"The colors have to be tough and they also have to be beautiful, rich and in most cases, have a degree of sparkle and gloss that does not diminish over time," said Jon Hall, an automotive color expert with BASF Coatings.

Sparking a Revolution
The use of effect pigments has become mainstream in the automotive market-as much as 75% of automotive colors in the world contain some kind of effect pigment, according to industry experts. A quick glance at late model cars on the road today shows just how far the technology has come from the first metallic effects used in the 1950s. Today's state-of-the-art formulations have enabled automakers to create shades that have delivered on designers' dreams and caught consumers' fancy.

The shade that has really grabbed consumers' attention is silver. Riding the top of the popularity chart for years, the slick hue is undergoing change thanks to exploration with new effect technologies. Coatings makers are forecasting new silvers bolstered by innovative effects, brighter, more fluid-looking silvers and silvers with more sophisticated color shifting effects.

The transformation of silver is testament to the usually evolutionary nature of color in the automotive industry. More dramatic changes in color and effects are usually sparked by a major breakthrough in technology.

"New effects tend to evolve over many years but they typically begin with a discovery," said Hall, who cited the Mystic Mustang as an example. BASF researchers and designers wanted to go beyond the metallic effect and pearl effect to achieve color change within the same paint film. This led to the Mystic Mustang in 1995, which featured the first strong color shifting effect the industry had ever seen. While the extreme color-shift showcased on the Mystic Mustang has seen greater usage in limited production runs or custom finishing jobs, it sparked the use of color shifting pigments that remain popular today.

Leading automotive coatings suppliers continue to push the envelope when it comes to color and effects. The use of effect pigments is helping them deliver more cost-effective products and open up opportunities for customers with production issues.

"We have been looking at ways to achieve a tri-coat look in a two coat system. Standard mica flakes, aluminum and color shifting flakes are some examples of what we have looked at to try to achieve this," said Jerry Koenigsmark, manager, product design, North America for PPG. "It will allow automotive manufacturers that have production restrictions to have color that looks like more than it actually is. It is also more cost effective."

Supplier Developments
Pigment suppliers are working on new high performance and special effect pigments to deliver the visual punch and performance characteristics coatings makers demand. Work centers on lightfastness, durability and cleanliness among other key attributes across a range of end markets, such as architectural, industrial and automotive.

Heubach is offering new indanthrone blue and anthanthrone red technology. According to Don McBride, COO of Heucotech Ltd., the company's newest indanthrone blue product will provide higher strength which is expected to increase the overall efficiency of PB 60s in coatings, and its anthanthrone red (PR 168) is well suited for demanding applications such as automotive and architectural coatings that need a very yellow shade red with excellent fastness properties. In addition, Heubach has also launched Tico high performance titanium color pigments, which McBride contends deliver a new range of high performance yellow, orange and red colorants to the market.

Clariant has added high fastness red shades to its high performance pigments stable based on diketopyrrolopyrrol (DPP) chemistry. The new high performance pigments (with the color index pigment red 254) are Hostaperm Red D2G 70 LV 2647, a high quality red pigment suitable for use in automotive OEM finishes and refinishes, and Hostaperm Red D3G 70 LV 2884, a high performance red pigment intended for use mainly in industrial paint. The pigments will be produced at a dedicated production plant at Clariant's HPP1 facility in Frankfurt, which is scheduled to come online in the fourth quarter. Samples of the new DPP pigments from the pilot plant are currently available.

In addition, Clariant's pigments and additives division is also offering two innovative ruby pigments-Hostaperm Rubine D3B LP 2615 and Hostaperm Rubine D3B-WD LP 2707-which exhibit high transparency and excellent fastness properties. Compared to other commercial red pigments based on DPP chemistry, they offer higher color strength and the specially modified surface of Hostaperm Rubine D3B results in very good rheological properties and significantly improved resistance to flocculation, according to Clariant. Both can be used in combination with effect pigments such as aluminum bronzes or mica pigments.

Eckart is helping coatings formulators answer the needs of designers that want to push the envelope in terms of brightness and unique attributes. The company's newest offerings include Platinum pigment, an ultra-smooth non-leafing pigment that delivers outstanding brightness, and new additions to its SDF 6 series. SDF 6-1101 and SDF 1501 are non-leafing pigments that provide unique silver and polychromatic effects, according to the company.

EMD Chemicals offers Colorstream multi-color effect pigments-silicone dioxide flakes coated with metal oxides-that can be used across a wide range of OEM products from transportation to packaging to electrical appliances to audiovisual, computer and communication equipment. Even under subdued light conditions, Colorstream pigments display attractive color travel, according to EMD. The company also offers Xirallic high chroma crystal effect pigments for industrial and automotive coatings as well as BiFlair effect pigments and dispersions for paint and industrial coatings used on metal, plastic, wood and leather.

Engelhard's new offerings include Lumina russet and copper pigments, a range of mica-based, metallic-looking pigments that deliver rich, earthy rust and copper effects to coatings. Both offer increased chromaticity, advanced color purity and more brilliance and hiding capacity. They are compatible with solvent- and water-based liquid coatings and powder coatings, according to the company.

"[High-performance and special effect pigments] provide the OEM formulator with a very wide palette of color choices for their automotive coatings," said Robert Schweitzer, general manager, coatings business unit, performance pigments, at Sun Chemical. "The HPPs provide bright and intense color shades, while the Special Effect Pigments add the 'sizzle on the steak,' Today's HPPs provide the necessary transparency that permits the formulator to use the wide variety of special effect pigments."

Among Sun Chemicals' newest products is Perylene Red, Perrindo Maroon 179, 229-8765, which is tailor made for automotive aqueous paints being easily dispersible and exhibits are great degree of transparency that allows the formulator to use special effect Pigments to his/her hearts content."

To date, great strides have been made in pigment technology, especially in the automotive market where the synergistic relationship between high performance and special effect pigments have yielded brighter colors, greater sparkle and more dramatic pearl effects even as paint film thickness has thinned.

"That's a good way to realize how much coatings technology has improved over the years," said Hall. "Those sparkling effect pigments are usually combined with high performance color pigments to produce the beautiful colors that we see on the road today."

Still, coatings customers want the next "what's new"-and paint makers need to work with pigments suppliers to take them there.

"We are constantly being challenged to develop new exciting looks using the latest effect pigment technology," said Koenigsmark. "The liquid metal look is something designers have been wanting for the last few years. Small steps have been made, but until some breakthrough in technology happens, they will continue pursuing," he added.

There is also the eternal quest for a better red. "The pursuit for a brighter red, either metallic or solid shades, has always been of interest to the automotive industry," said Koenigsmark, who said PPG is exploring technology to create deeper/cleaner colors.

But that's only half the battle. A dramatic red that lacks staying power won't cut it. "Trying to get closer to a dye or candy red is a goal that we have set for ourselves," said Koenigsmark. "Of course we have to make sure that they perform at a high level."