Premiered at the 78th International Motor Show in Geneva

The “i-mode” exhibits many outstanding features that are the result of close development collaboration between Hyundai and Bayer MaterialScience AG.

Pittsburgh, May 12, 2008 –– With its sporty-looking contours, the “i-mode” certainly looks impressive. One thing that immediately catches the eye is its new door design, which eliminates the center pillar. In addition, the cockpit of Hyundai's new HED-5 “i-mode” concept car promises plenty of driving pleasure. In fact, the vehicle combines the advantages of a van with those of a sedan. Many of its outstanding features have come about as a result of close development collaboration between Hyundai and Bayer MaterialScience AG (BMS).

“For us, it was a special challenge to work on a close-to-production concept car with one of the biggest and fastest-growing international car manufacturers. This vehicle provides an impressive demonstration of our latest products and our know-how in innovative plastics processing,” explains Dr. Klaus Zander, BMS key account manager for Hyundai.

“We at Hyundai were looking for a collaborator that understands the way we think in auto design, and Bayer MaterialScience was certainly the right choice for us,” observes Helmut Weixner, head of Engineering Design at Hyundai Motor Europe.

Polycarbonate Glazing – Less Weight and More Design Freedom

One striking feature of the “i-mode” is its transparency. It has a total of 11 glazing components made of Makrolon® polycarbonate. The windscreen and backlite, four moving and two fixed side windows, two hinged windows, and the large roof module are all made of this BMS polycarbonate. The determining factor in its selection was the freedom of design afforded by this high-tech thermoplastic. For example, the backlite extends up into the roof. “It bends around almost at right angles, which would be impossible with glass,” says Ulrich Grosser, a design expert at BMS.

The roof module consists of two long panels separated by a narrow center strip. Both panels have a sharp edge that runs smoothly into the backlite. This styling element, which underscores the dynamism of the vehicle, would also have been impossible to construct with glass.

Because of the large number of glazing elements and their considerable size, the material also had to be much lighter than glass. “With our polycarbonate, we can produce transparent panels that are up to 50 percent lighter than their glass counterparts,” adds Grosser.

To ensure effective heat protection in the interior of the “i-mode” on sunny days, the design team has used a new generation of infrared-absorbing transparent colors coordinated to Makrolon polycarbonate. This glazing absorbs the heat of the sun's rays better than certain types of glass, but with comparable light transmission. In addition, it provides effective protection against UV radiation – unlike similar elements made of glass.

BMS, a market leader in polycarbonate automotive glazing, has once again underscored its pioneering role as a development collaborator for polymeric raw materials. The “i-mode” has also provided BMS with an excellent opportunity to display its wide-ranging know-how along the entire polycarbonate glazing development and production path.

Self-Healing, Two-Component Polyurethane Top Coat – Scratches That Disappear

The bodywork of the “i-mode” shimmers in a stylish silver metallic color called “Topaz Silver.” In fact, the coating system used for Hyundai’s concept car marks the premiere of a two-component polyurethane topcoat based on new raw materials from BMS. What is special about the vehicle’s finish is its extreme scratch resistance and its self-healing properties. Small scratches simply “melt away” under the influence of the sun’s heat so that the finish retains its new look longer.

Scratch resistance and self-healing characteristics may sound like contradictions, but they are not necessarily so. A combination of properties such as this can be achieved by altering the coating's molecular network. The scratch resistance of a polyurethane finish generally can be increased by raising the density of the molecular network, but to ensure that the coating does not become brittle in the process, the areas between the linkage points of the network must be made elastic. “We do this with the aid of our new, highly functional hardener, Desmodur® XP 2679 polyisocyanates. In combination with suitable Desmophen® polyols – the second basic raw material in this polyurethane coating – it forms a tight network with elastic network chains,” says Dr. Markus Mechtel, who specializes in bodywork finishes at BMS. The resulting polyurethane clear coat is not only scratch resistant and self healing, but it is also highly chemical resistant. Furthermore, it also offers environmental friendliness as it is formulated with a high content of polymer and only a small amount of organic solvents.

Polyurethane Soft-Feel Coating – Optimized Stability and Long Service Life

The soft-feel coatings applied to many of the plastic controls and surfaces in the cockpit of the “i-mode” are based on a new generation of high-grade coating materials in the Bayhydrol® and Bayhydur® polyurethane dispersion series.

The soft-feel coatings applied to many of the plastic controls and surfaces in the cockpit of the “i-mode” are based on a new generation of high-grade coating materials in the Bayhydrol® and Bayhydur® polyurethane dispersion series. They give the “cold” plastic surfaces a soft, warm feel that is particularly pleasant to the touch.

“Our new polyurethane raw materials are applied by spraying, resulting in soft-feel finishes that have a much longer service life and better aging resistance than the former systems. Even light-colored surfaces barely yellow at all under the effect of heat,” explains Dr. Christoph Irle, an expert in soft-feel coatings at BMS. Because of its matte finish, the driver is not irritated by troublesome reflections. Another bonus is that these coatings are waterborne and, therefore, particularly environmentally friendly. The polyurethane raw materials do not contain any plasticizer, so the coatings exhibit minimum fogging and very low emissions.

LED Headlamps – Polycarbonate Beats PMMA and Glass

The “i-mode” is equipped with LED headlamps. The job of bundling and focusing the dipped and full-beam light is performed by special collimator lenses made of Makrolon® polycarbonate.

Headlamps that incorporate light-emitting diodes (LEDs) as the light source are becoming particularly popular in automotive manufacturing because of their low energy consumption and high life expectancy. The “i-mode,” too, is equipped with such LEDs. The job of bundling and focusing the dipped and full-beam light is performed by special collimator lenses made of Makrolon polycarbonate. “In the production of precision lens systems, polycarbonate has many advantages over glass and PMMA. First of all, it is lighter than glass and does not have to be polished. In addition, the delicate lens geometries can be produced with greater precision and more economically than with processes based on glass,” says Dr. Martin Döbler, an expert in plastic optics at BMS.

Compared with PMMA, Makrolon polycarbonate resin is not only tougher and more heat-resistant, it also has a higher refractive index. This means that the collimator lenses can be made thinner. Because of the enormous application potential of Makrolon polycarbonate in LED-focusing optics, BMS has made considerable investments in injection-molding equipment and know-how in this field. “We can now produce components for high-precision focusing optics from special, custom-made grades of Makrolon resin. The profile of the light reflected by the optical systems correlates extremely accurately with the simulation of its geometries,” says Döbler.

About Bayer MaterialScience
Bayer MaterialScience LLC is one of the leading producers of polymers and high-performance plastics in North America and is part of the global Bayer MaterialScience business with nearly 15,400 employees at 30 sites around the world and 2007 sales of 10.4 billion euros. Business activities are focused on the manufacture of high-tech polymer materials and the development of innovative solutions for products used in many areas of daily life. The main segments served are the automotive, electrical and electronics, construction, medical, and sports and leisure industries. Our inorganic basic chemicals unit produces chlorine and related essential products for the chemicals industry. Let us give life to your vision. Bayer MaterialScience – Where VisionWorks.

Bayer Corporation, headquartered in Pittsburgh, is a subsidiary of Bayer AG, an international health care, nutrition and high-tech materials group based in Leverkusen, Germany. In North America, Bayer had 2007 net sales of 8.1 billion euros and employed 16,800 at year end. Bayer’s three subgroups, Bayer HealthCare, Bayer CropScience and Bayer MaterialScience, improve people’s lives through a broad range of essential products that help diagnose, prevent and treat diseases; protect crops and enhance yields; and advance automobile safety and durability.