Bring back the steel? The growth of plastics in automotive applications.

The development of plastics has evolved from the use of natural materials to the use of chemically modified natural materials and, finally, to completely man-made molecules. Plastics continue to improve, to afford flexibility, high-impact, and strength. In automotive applications, plastics have increased in utilization to comprise approximately 10% of the total vehicle weight. They offer increased ductility, freedom from corrosion, and increased styling capability. Although plastics have had a remarkable impact on our culture, it is obvious that there is a price to be paid for their use. Plastics are almost too good, as they are durable when processed correctly, but easily damaged when utilized in the incorrect application. Plastics also degrade very slowly, making recycling mandatory. And finally, while plastics consume only 4% of the world's oil production (petroleum is the raw material that is chemically altered to form commercial plastics), their cost hinges on the cost of petroleum. As petroleum prices increase, so too will the cost of plastic. In 2004, the higher price of plastic forced many plastic manufacturers out of business, and forced many automotive suppliers to look into alternative replacements. With publications such as USA Today reporting that current oil reserves will only last 40 years, scientists continue to seek cheaper alternatives to plastic.

This article summarizes the history of commercial plastic development, with a focus on utilization of the materials in automotive applications. Damage criteria of plastic components, namely scratch, oxidative degradation, and impact, are discussed in relation to coatings and processing robustness. Environmental regulations, particularly in relation to recycling mandates, are explained. And finally, trends in alternative material development, including bioplastics, films, ceramic coatings, and nano-composites, are formulated.

Keywords: Flow agents; dynamic mechanical properties; fluorescence, hardness, scratch resistance; UV spectroscopy; photodegradation; acrylics; isocyanates; melamine-formaldehyde resins; photostabilizers; polyurethanes; solventborne; UV, EB, radiation cure; waterborne; service life prediction; weatherability; automotive--OEM; high-solids; latex; plastics

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The first man-made plastic was unveiled by Alexander Parks at the 1862 Great International Exhibition in London. This material--which the public dubbed Parkesine--was an organic material derived from cellulose that once heated could be molded but that retained its shape when cooled. Parks claimed that this new material could do anything rubber was capable of, but at a lower price.

Within the ensuing years, several "new" plastics were unveiled--celluloid in 1866 to replace ivory in billiard balls, Bakelite in 1907 to be utilized in most weapons used in the Second World War, cellophane in 1920, and nylon in 1939. However, it was not until H. Staudinger in Germany recognized the structural nature of plastics that the revolution in plastics began. Carothers, for example, found that by substituting and inserting elements into the chemical backbone of polymers, new materials and uses could be developed. During the 1940s, the world saw the use of such materials as nylon, acrylonitrile, neoprene, styrene butadiene rubber, poly(ethylene), and many more polymers take the place of natural material supplies that were becoming depleted.

Since the 1950s, plastics have grown into a major industry that affects all of our lives--from providing improved packaging to giving us new textiles, to permitting the production of cutting edge technologies that afford such products as televisions, computers, and cars. Since 1900, plastic has been the most used material in the world and was voted one of the top news events of the century.

Plastics acceptance in the automotive industry can be traced back to the early part of the 20th Century, although it was not until advanced, high-performance polymers were developed that plastics became a material of choice for automakers. Plastics continue to encompass many segments of the automobile due to their light weight, increased durability, increased design flexibility, low temperature impact resistance, and efficient manufacturability.

Global vehicle demand in 2004 was estimated to be approximately 54.6 million units, with the car market at approximately 36.6 million units and the commercial vehicle market at approximately 18.1 million units. (1) Vehicle demand in NAFTA and Western Europe continues to fall while the emerging markets of Asia Pacific and Central and Eastern Europe report growth rates of approximately 3.4%.

About 40 basic types of plastics are used to produce an automobile today, broken down by those included in the interior, body (exterior), underhood, and chassis components of the vehicle. Of the 2.5 billion kilograms of plastic utilized in North American production, the interior segment of the vehicle utilizes the most plastic while the exterior segment is exhibiting the fastest growth.

While roughly 40% of the exterior plastics utilized in the automotive industry today are molded-in-color and unpainted, automotive manufacturers do chose to paint for one of several reasons: aesthetics and/or improved durability (to encompass chip resistance, ultraviolet and chemical resistance, and scratch resistance). The exterior segment of North American automotive plastics accounts for $364 million in annualized paint consumption, which is growing at a rate of 4%. (2) Of that paint usage, less than 19% is radiation curable, with the majority being high-solids followed by waterborne.

The remainder of this article will discuss the attributes required for coatings on plastics, namely adhesion, aesthetic qualities, and damage resistance requirements related to cohesive integrity (gouge), chip resistance, chemical etching resistance, ultraviolet (UV) damage resistance, and scratch resistance. Considering the film thickness of the coatings used on plastics (approximately 50 microns or less), one could postulate that the science involved in these thin layers is nothing less than miraculous!

KEY COATING REQUIREMENTS

Adhesion

As mentioned, approximately 40 basic types of plastic are used to produce an automobile today, broken down by those included in interior, body (exterior), underhood, and chassis components. A wide variety of plastic types are utilized in each segment, with the most common families of plastics being poly(urethane), poly(propylene), poly(ethylene), poly(vinyl chloride), nylon, rubber-modified poly(propylene) [commonly referred to as thermoplastic(olefin) (TPO)], acrylonitrile butadiene styrene, thermoplastic and thermoset poly(ester), and poly(carbonate). Each type of plastic is chosen to meet stringent engineering requirements with respect to fatigue, chemical resistance, and other physical properties. As mentioned previously, lighter weight and, thus, improved fuel emissions, are also key contributors to plastic utilization. The specific gravity of most plastics (0.9-1.6 g/[cm.sup.3]) is much lower than that of steel (7.8 g/[cm.sup.3]), aluminum (2.6 g/[cm.sup.3]), or magnesium (1.75 g/[cm.sup.3]). A rough rule of thumb is that a 10% reduction in weight improves gas mileage by about 7%. Thus, the use of plastics (approximately 10% of the vehicle weight) significantly improves gas mileage, reducing greenhouse gases.

Cost of the plastics consumed in the fabrication of a vehicle is of utmost importance in these price conscious days of automotive retailing. While plastics consume only 4% of the world's oil production (petroleum is the raw material that is chemically altered to form commercial plastics), their cost hinges on the cost of petroleum. As petroleum prices increase, so too does the cost of plastic. In 2004, the higher price of plastic forced many plastic manufacturers out of business, and forced many automotive suppliers to look into alternative replacements. One major plastic that most suppliers turned to was the olefin type, namely poly(propylene).

Due to the need for improved crash safety requirements, many suppliers of poly(propylene) looked to increased elastomer or rubber modification of the material. The resultant plastic, thermoplastic olefin (TPO), has become the mainstay of commercial use, accounting for nearly 20% of the most common plastics used in automotive applications. Due to its inherently low surface-free energy, however, adhesion of coatings has most often been referred to as "problematic."

The adhesion of organic coatings to a TPO is strongly dependent upon the type of surface treatment the thermoplastic material receives prior to painting. One such treatment involves the application of a thin layer (7 to 14 [micro]m) of an adhesion promoting primer that is comprised of a chlorinated poly(olefin) (CPO). Although materials of this type are known to establish good adhesion between the TPO and subsequent paint layers, the mechanism of adhesion promotion is not unequivocally known.

The mechanism by which CPO coatings promote adhesion to TPO has been speculative over the last several years. (3-7) Waddington and Briggs (7) have reported experiments that suggest CPO promotes adhesion by diffusing into the substrate and forming a chain entangled interphase between substrate and adhesion promoter. They used secondary-ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS) to study the peel failure between a CPO and two grades of TPO: one that exhibited strong adhesion and one that exhibited weak adhesion. Chlorine was detected on the surface of the TPO that exhibited strong adhesion, but not on the surface of the TPO that exhibited weak adhesion. In a separate experiment, they coated the two grades of TPO with a CPO and measured the amount of chlorine at the air interface of the CPO. Lower levels of chlorine were found over the TPO grade that exhibited better adhesion. This depletion of chlorine supported a mechanism based on the diffusion of CPO into the TPO.

Clemens, et al. (3) utilized surface characterization techniques, including electron spectroscopy for chemical analysis (ESCA), energy dispersive X-ray analysis (EDXA), time-of-flight secondary ion mass spectrometry (TOFSIMS), and transmission electron microscopy (TEM), in attempts to elucidate the mechanism by which CPO primer coatings promoted adhesion of paints to polypropylene and TPO. The coatings, their interphasial failures, and taper-cross sections were studied, using both waterborne and solventborne CPO primers. It was determined that CPO primers did not penetrate deeply into the polyolefin substrates, but were quite mobile following application of the topcoat. The mechanism by which CPO primer coatings promoted adhesion was discussed in terms of better surface wetting and, thus, contact, allowing for sufficient dispersion interactions with the substrate, and intermixing/bonding with the more polar topcoat. Solventborne CPOs generally showed failure at the CPO/polyolefin interface when dried at ambient temperatures. Waterborne CPOs showed equivalent adhesion promotion, although cohesive failure within the primer layer was more common and appeared to be a function of formulation parameters.

Work done by Ryntz and co-workers (8,9) demonstrated that adhesion to TPO is strongly influenced by the type and amount of solvent contained within the adhesion promoter (CPO containing primer) as well as the surface morphology of the TPO substrate. The morphological changes at and near the surface of TPO affect not only paint adhesion but also the cohesive integrity of the painted plastic assembly.

Morphological changes in the TPO substrate are accomplished in the presence of solvent from the adhesion promoter (as well as from subsequent topcoats) and vary depending upon bake time and temperature. Thermoplastic olefin morphology is indicated by a closely packed, crystalline surface layer of PP under which lies a rubber-rich boundary. Adhesion attainment is dependent upon the diffusion of the CPO adhesion promoter through the crystalline PP surface layer and its swelling and entanglement with the rubber-rich layer beneath it. In general, a greater degree of rubber swelling is indicative of a higher amount of solvent penetration. Initial adhesion to TPO appears to be a function of polypropylene crystallinity at the surface only, as it relates to the ability of solvents to penetrate through and into the rubber-rich layer beneath it.

One must be aware, however, of the rubber swelling effect on the ability of the TPO to withstand stress (compressive or shear) within its boundary layers in a swollen state. For example, when the rubber is swollen (elongated) to near its tensile break point, it would require little imparted stress to delaminate the rubbery boundary layer from the bulk morphology of the TPO beneath it. Peel strengths (given in terms of cohesive integrity values) performed on TPO plaques exposed to a compatible solvent (xylene, solubility parameter near that of TPO) indicated that those plaques exposed to solvent (30 min at 25[degrees]C) afforded lower values than those not exposed to solvent. (8) This variance may be due to increased swelling or plasticization of the top TPO layers. When the same plaques were swollen by slow evaporating (Aromatic 100) versus fast evaporating (toluene) solvents and then flashed-off through the use of an infrared oven, very little difference in peel strength values was seen. In order to attain maximum adhesion to TPO, therefore, one tries to maximize solvent diffusion into the substrate while minimizing the amount of solvent remaining in the substrate after bake.

Solvent diffusion, however, is only indicative of the ability of the CPO, the actual adhesion promoting moiety, to be carried into the substrate and not of the actual CPO penetration. In order to understand the amount of diffusion accomplished by both the CPO and solvent, a fluorescent "tagging" experiment was performed to monitor the depth of interpenetration of both substances via fluorescent microscopy. The use of an unbound fluorescent dye, 7,7'-dimethyl-4-aminocoumarin, in the solvent was utilized to follow the depth of solvent penetration. A covalently bound dye, attached directly to the maleic anhydride component of the CPO, was utilized to follow the depth of CPO penetration. This technique is not unfounded, being studied by Li, et al., (10) to determine the surface morphology of a polymer blend through laser confocal fluorescence microscopy.

The ability of the solvent to swell the TPO substrate was studied in relation to the depth of solvent penetration into the substrate versus the bake temperature. This was accomplished through the use of fluorescence microscopy, as described above. The depth of penetration of the "free" dye, 7,[7.sup.1]-dimethyl-4-aminocoumarin, was measured in a 70/30 PP/rubber w/w compounded TPO as a function of bake temperature while maintaining equivalent solvent composition (80/20 xylene/Aromatic 100 based on weight). The dye penetration, as viewed from a cryogenically "cracked" cross section of the treated TPO substrate, was found to increase as a function of increasing bake temperature. The depth of penetration was followed by monitoring the increase in the optical intensity of the dye fluorescence. Dye penetration values were taken at 50% of the initial intensity of the fluorescence trace. At room temperature, the dye migrated roughly 150 [micro]m into the substrate, whereas at 121[degrees]C, the depth of penetration increased to roughly 600 [micro]m. This depth of penetration was found to correlate with the amount of free dye carried into the substrate by the solvent and not with the actual diffusion of the much higher molecular weight CPO molecule.

In a separate fluorescence experiment, the fluorescent tag was covalently bound directly to the maleic anhydride functionality of the CPO molecule. The penetration of the CPO molecule was then determined by monitoring the fluorescence with a laser confocal microscope as a function of temperature. It was demonstrated that as the fluorescently tagged CPO adhesion promoter was baked, the fluorescent regions appeared to coalesce. One can postulate that the CPO diffuses through the TPO surface and entwines with the rubber-rich areas of the TPO directly beneath the surface. As the swelling continues, through the interaction of the solvent-laden CPO with the rubber, the CPO/rubber regions begin to break through the surface and coalesce.

Laser confocal fluorescence microscopy also confirmed depths of penetration of the fluorescently tagged CPO. The depth of penetration was determined by rastering the laser across a selected section of the TPO at various focal planes. The depth of CPO penetration was then re-created by the addition of various focal plane depths where fluorescence was seen. The fluorescence penetration, after application of the fluorescently tagged CPO and a 30-min dwell time at 25[degrees]C, was approximately 4 [micro]m. After a 121[degrees]C bake, the depth of fluorescence increased to ca. 10 [micro]m.

Time-of-flight secondary ion mass spectrometry was utilized to evaluate the depth of penetration of the adhesion promoter based on imaging of the chloride ion contained within the CPO. The chloride images and line scans of cross-sectioned samples of the chlorinated polyolefin-based adhesion promoter coated TPO system were measured by pixel intensity of the chloride ion (as determined with the gallium laser). A well-defined line, representing the adhesion promoter layer was readily apparent in the images obtained. The thickness of this layer was about 10-15 [micro]m. Localized areas of high intensity chloride were observed along this sharp line and were suggestive of topographical anomalies introduced into the sample surface by the microtoming technique used to prepare the sample. This turns out to be a critical factor in determining the degree of useful information that can be gained from the analysis. Most importantly, chloride diffusion into the TPO appeared to be on the order of 3 to 9 [micro]m.

The diffusion of a chlorinated polyolefin polymer having a molecular weight of about 15,000 could reasonably be expected to result in several orders of magnitude less diffusion into the TPO substrate. However, non-Fickian behavior resulting from solvent induced swelling, crazing, and porosity induced by phase separation of the elastomer from the polypropylene would not be unexpected.

These results correlate quite well with those determined by Komatsu, et al., (11) as well as the TOFSIMS studies. The slightly higher degree of interpenetration of the CPO, as suggested by the fluorescent studies relative to the SIMS data, can be explained in the context of molecular weight. A gel permeation chromatography (GPC) examination of the tagged CPO showed small amounts of low molecular weight moieties present within the tagged CPO. The low molecular weight components in the CPO compound are believed to contribute to the deeper depths of penetration.

The effects of structural differences within the chlorinated polyolefins and the effect they have on coating performance is described in work by Fujimoto (12) and Ryntz. (13) In effect, the work by these authors shows the effect of chlorination of the polyolefin on the adhesion and crystallinity of the polymer. In summary, at higher degrees of chlorination the crystallinity of the chlorinated polyolefin lessens, thus making it more compatible with other typical film-forming compounds used in coatings. However, lower levels of chlorine translated to better adhesion to olefinic substrates. These two opposing parameters must be balanced with one another to provide adhesion promoters with the best balance of properties.

In the work performed by Ryntz, (14) the degree of maleation of the chlorinated polyolefin, in conjunction with the chlorinated polyolefin molecular weight and molecular weight distribution, was also shown to affect the degree of adhesion between the chlorinated polyolefin and the TPO substrate. The resins with the highest peel strength were those with the highest chlorine levels, some level of maleic anhydride, low number average molecular weight, low polydispersities, and low viscosities.

Although the work described above identified the importance of CPO structural attributes on adhesion of CPO to TPO, another anomaly was found to occur with respect to adhesion and location along the TPO substrate. When swelling experiments were performed near or away from the proximity of the "gate" (the location in an injection-molded substrate where the hot plastic melt is introduced into the part), variations in swellability occurred. (8) It was expected that those materials with more rubber would swell more. However, it was noted that the areas "near" the gate in the TPO part actually exhibited lower amounts of swelling.

In a separate experiment, the adhesion of the topcoat "near" and "away" from the gate in TPO injection-molded plaques was determined via a gas soak test. (14) It was found that when white topcoated, black pigmented TPO substrates were cross-hatched and immersed in ethanol laden gasoline, the adhesion began to become differentiated at the different locations. It was determined that lower modulus (higher rubber content) TPO materials exhibited better adhesion than those with higher modulus. It was also evident that the area "near" the gate in higher modulus substrates began to fail before the area "away" from the gate.

Several researchers have examined the importance of the variation in TPO surface and its effect on adhesion. (9,15,16) The surface morphology of semicrystalline polymers has been shown to be either similar to or substantially different from that present in the bulk as a consequence of processing conditions. (17) The relatively minor changes in morphology lead to specific changes in the chemical, physical, and mechanical properties of the surface and of the interior or bulk. Since chemical reactivity, gas permeability, adhesion, friction, and abrasion resistance are dependent on surface morphology, it is of interest to delineate those factors that influence the formation of surface structure.

Cohesion

It has been found that cross-polarized light can be utilized as an effective means with which to measure the skin/shear layer in injection-molded TPO. (9) The shear zone, under cross-polarized light, is birefringent and can vary as a result of the way a part is filled. Near the injection molding gate, the shear layer is generally thinner than the location away from the gate. It was also determined that the skin layer near the gate exhibited a greater "microhardness" than that away from the gate, possibly as a result of increased packing density or variations in surface crystallinities. The surface hardness variation may account for the adhesion variations, since it was also determined that areas "near" the gate exhibited lower dye penetration values.

Fujiama and Kimura (15) found that a relationship existed between the thickness of the skin layer in polypropylene and its yield strength. The skin layer is composed of a "shish-kebab" like structure where crystalline lamellae align perpendicular to the flow direction (referred to as transcrystallinity). Generally thicker shear zone skin layers afforded higher tensile strengths.

The types of materials that contribute to the "skin layer" in injection-molded TPO can vary. (9) If the TPO contains low molecular weight additives, e.g., processing stabilizers, viscosity adjusters, or even process degraded or low molecular weight "tails" of the polymers, one can experience additive migration to the TPO surface. The species migrating to the surface can amount to formation of a "weak boundary layer (WBL)" that exhibits poor cohesion to the bulk TPO.

Gouge Resistance

The relationship of "skin layer" thickness to cohesive integrity of the TPO substrate became an important consideration when a topcoated substrate was exposed to a compressive/shear stress. (18) Thermoplastic polyolefin substrates, under compressive tensile shear stress, often delaminate cohesively within the TPO substrate, where cohesive delamination was found to be dependent on load, temperature, and shear velocity parameters of the tensile shearing event. The failure was found to occur in the weak boundary layers of the TPO substrate, most often between 25 and 100 [micro]m into the substrate.

It is interesting to note that if one exposes unpainted TPO to the compressive/tensile shearing, no failure occurs. It appears that the coefficient of friction of the surface, being very low for poly(propylene), allows the shear load to be transmitted across the monomolecular low friction layer. When painted, however, the frictional coefficient of the paint, being higher than that of the TPO surface, allows the force to be transmitted into the painted TPO surface.

It was determined that the most significant parameters in the paint which affect "gouge" damage resistance are glass transition temperature, secant modulus at break, and the static coefficient of friction. (19) In order to better understand, however, the attributes of the coating type utilized in painting TPO, in relationship to the gouge resistance of the system, a model coating system was designed. (18) Water-based hydroxyl functional styrenated acrylic clearcoats, containing nonaggressive solvents so as not to swell the TPO, were formulated. The gouge resistance of the formulated clearcoats was measured on a compressive/shear loading device. Figure 1 depicts the gouge resistance of the clearcoats. The gouge area/energy rating for the most severe test conditions, labeled DOE Run #8 (68.3[degrees]C, sliding velocity of 3.4 cm/sec, and a load of 272.4 kg) versus the less severe conditions (labeled DOE Runs #2, #4, and #6, where the loads, sliding velocities, and temperatures are lower) are shown. The smaller the value (a rating of "0" depicts no damage), the better the performance. The coating formulation nomenclature is:</p> <pre> #77A, D, G, and J are hydroxyl functional styrenated acrylics with a [T.sub.g] of 45[degrees]C; where 77-D and J contain surface free energy modifier; where 77-A and D are not crosslinked, and where 77-G and J are crosslinked with a blocked isocyanurate. #77C, F, I, and L are hydroxyl functional styrenated acrylics with a [T.sub.g] of 65[degrees]C; where 77-F and L contain a surface-free energy modifier, where 77-C and F are not crosslinked, and where 77-I and L are crosslinked with a blocked isocyanurate. </pre> <p>As viewed in Figure 1, all of the coatings, regardless of the [T.sub.g] or crosslinker level, when formulated with added surface-free energy modifier (mar agent), showed no gouge (77-D, 77-J, 77-F, and 77-L). It appears generally that as the [T.sub.g] increased (77-C versus 77-A and 77-I versus 77-G) the gouge damage increased. It is believed that the brittleness of the higher [T.sub.g] resin accounts for brittle fracture of the coating during applied compressive load, resulting in asperity formation and subsequent gouging. Added crosslinker, 77-G versus 77-A and 77-I versus 77-C, appeared to improve gouge resistance. This is believed to be due to an increase in tensile strength of the coating when crosslinked.

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Chip Resistance

The ability of a coated plastic to withstand stone/gravel impact has been the subject of numerous research articles. (20-22) Test methods to simulate coating damage incurred as a result of stone impact or gravel erosion have been developed and include the "precision paint collider" stone impactor (20) and the Erichsen alumina oxide abrasion (erosion) blaster. The damage imparted in such testing methodology has been correlated by optical image analysis as well as by gloss retention in abraded versus nonabraded areas on the exposed coated substrates. An in-depth analysis of such impact damage on painted TPO often displays cohesive "ripping" within the substrate which can be numerically simulated through delamination under stress of TPO weak boundary layer. (22)

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Through utilization of the "precision paint collider" impact damage on TPO was assessed via digital imaging analysis of the impacted area. Generally, the greater the temperature at which the impact was performed, the greater the amount of damage was produced. Two-component topcoats (those crosslinked with isocyanates) generally performed worse than one-component (melamine crosslinked) topcoats.

In the abrasion (erosion) resistance testing (21) utilizing the alumina oxide particles (20 grit size), it was determined that not only topcoat but also substrate played an important role in affecting the damage assessed by impinging alumina oxide erosion. Two-component topcoats generally performed worse than their one-component counterparts.

Figure 2 depicts damage incurred during grave/stone impact (SAE J400) of one-component topcoated TPO substrates. (23) The effect of TPO substrate change, as influenced by modulus increase in reactor type TPO compounds, on resultant chip damage is displayed. As the modulus of the substrate was increased, mainly through increasing the crystallinity of the poly(propylene) homopolymer portion of the impact copolymer blend, the chip resistance of the painted composite decreased. This result was not unexpected based on previous remarks in this article. One would expect that as the crystallinity of the substrate increased, the adhesion of the topcoat would decrease due to the lower penetration capability of the adhesion promoter. One would also expect that as the crystallinity of the substrate increased, the stress-field at the interphase of the TPO/paint boundary would change, hence the worsening of the chip resistance.

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The effect of paint processing parameters on resultant chip performance of painted TPO substrate was also studied. The paint utilized was the same one-component melamine crosslinked acrylic polyol described above. The bake temperature time was kept constant at 30 min ambient. SAE J400 was employed with white basecoat/clearcoat samples prepared wet-on-wet with a three-minute flash time between basecoat and clearcoat. A conventional modulus (150 kpsi flexural modulus) reactor grade TPO substrate was utilized in all the following studies. Chip density was the response measured. Independent variables studied included clearcoat film build, bake time, and testing temperature.

As can be seen in Figure 3, the higher clearcoat film build affords better chip performance (e.g., lower chip density). This may be due to the ability of the thicker clearcoat to dissipate the stress impact more within itself as opposed to translating the energy to the coating/substrate interface.

The effect of basecoat/clearcoat bake temperature was also assessed. As shown in Figure 4, the higher bake temperature affords better chip resistance. Although hardness and toughness of the resultant basecoat/clearcoat matrix was not checked, the results may be due to the ability of a higher bake to induce a more fully crosslinked matrix. The higher crosslink density may account for a tougher coating that can dissipate the impact stress within itself, as described above, not allowing the stress to translate to the coating/substrate interface.

Finally, the effect of test temperature was assessed on an identical set of panels, as utilized in Figure 2 with a film build of 1.5 mils. As seen in Figure 5, the panels tested at room temperature performed the worst, with little variation in chip density seen at the higher or lower testing temperatures. This was somewhat unexpected, in that higher temperatures usually decrease the cohesive integrity of the TPO and lead to cohesive ripping within the substrate.

Abrasion Resistance

As opposed to just simply looking at paint processing conditions on the performance of coated TPO substrates, the effect of topcoat, topcoat application method (basecoat/clearcoat wet-on-wet versus bake-on-bake), and abrasion resistance after simulated weathering was studied. Abrasion resistance (marring) was performed on an AATCC crockmeter equipped with a cloth pad (DP-cloth, HQ manufactured by Struers, Copenhagen, Denmark and distributed by VWR Scientific) fitted with 0.01 gram of 63 micron (220 grit) alumina oxide. A constant load of 940 grams was applied, the sliding velocity was maintained at approximately 21 mm/sec, and a total of two double rubs were performed on each sample. The abrasion resistance of black basecoat/clearcoat panels was measured based on 20[degrees] gloss loss. The abrasion resistance of the samples was measured prior to their weathering, while identical sets of panels were placed in a Xenon arc Weather-Ometer (borosilicate inner and outer filters, SAE J1960 specifications) and removed and retested after every 500 kJ of exposure.

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As shown in Figure 6, it is apparent that in their "green" states (e.g., before exposure to artificial weathering) the one-component clearcoat (1K) performs slightly better than its two-component counterpart (2K) (e.g., less gloss loss). After 1500 kJ of exposure in the Xenon arc Weather-Ometer however, the two coatings perform approximately the same. Usage profiles therefore should be developed that project requirements for coatings in their infancy as well as throughout their lifetime since performance seems to be predicted on lifetime.

The effect of one-component clearcoat coating application method was studied and the results are shown in Figure 7. Application methods were varied by either applying the clearcoat on a wet basecoat that had been flashed three min at room temperature prior to application, or by prebaking the basecoat at 121[degrees]C for 15 min prior to application of the clearcoat. From the results shown in Figure 7, the performance of the system is determined by the amount of artificial exposure the coatings experience. Early in their lifetime, it appeared that the bake-on-bake system performed better than the wet-on-wet. After 750 kJ of artificial weathering, however, the two systems performed identically.

Etch Resistance

The useful life of a coating on plastic may be shortened by the diffusion of pollutant gases (or ions formed upon reaction of these gases with water) into the paint/substrate system, followed by chemical reactions which result in degradation of the coating or substrate. Acid deposition is caused by sulfur dioxide (S[O.sub.2]) and nitrogen oxides (N[O.sub.X]: NO, N[O.sub.2]) emitted during the combustion of fossil fuels. As these gases travel through the atmosphere, they are converted to sulfuric and nitric acids. These acids are created by oxidants that are also formed in the atmosphere, from photochemical reactions involving N[O.sub.X] and volatile organic compounds (VOCs). Either the acids and gases are scavenged from the atmosphere by rain, snow, and hail (wet deposition), or they adhere to available surfaces (dry deposition). Acid rain, therefore, is a particular type of wet deposition that results in etching of automotive coatings. Of fundamental importance to the performance of the paint may be the permeability of the coating to the pollutants comprising the acid rain species.

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Many attempts have been made in the past to develop test procedures that can predict the acid etch resistance of automotive clearcoats. Methods such as the gradient bar method (a thermal gradient is produced along the panel being tested while acid exposure is conducted concurrently) and acid spotting method are just two examples being utilized in the industry today. In testing conducted on "acid resistant" clearcoats, diffusion and resultant resistance was determined by exposure of the coating to a mixture of acids over a period of time. (24) The testing solution was prepared by combining (by volume) 1N solutions of acids in the proportions 65% sulfuric, 30% nitric, and 5% hydrochloric. Four drops of the solution were placed on the panel to be tested and evaporated liquid was replaced every hour with additional 1N solution to maintain a constant drop size. At varying intervals, the panel was rinsed off with distilled water, dried, and evaluated for visible etching. The hour in which etching first occurred was recorded as failure.

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[FIGURE 9 OMITTED]

Figure 8 displays the resultant etch resistance of several commercial "OEM" (original equipment manufacturer) solventborne one-component (1K) melamine crosslinked coating systems. The basecoats in all cases were solvent-borne acrylic/polyester 1K melamine crosslinked black pigmented formulations. Longer exposure times (increased amount of hours elapsed before etching was visible) were indicative of increased performance. These findings suggested that coatings formulated with urethane provided better hydrolytic resistance than those formulated with melamine crosslinking. In fact, as acrylic modification was made to the urethane polyol formulation, the etch resistance was decreased. An additional formulation evaluated was a silane modified 1K melamine crosslinked acrylic/polyester (herein referred to as NCT = new clear technology), which performed similar to the 1K acrylic/polyester clearcoats.

Work done by Ryntz and Parker in the summer of 1994 evaluated the performance of several flexible basecoat/clearcoat systems for a period of 14 weeks in Blount Island (Jacksonville, FL) between the months of June and September. (25) Panels were exposed horizontally and washed with water every two weeks. Results depicted in Figure 9 were rated with the following scale: 9-12 = very severe etching; 6-8 = moderate etching; 3-5 = slight etching; 0-2 = no etching to slight water-spot that can be removed upon wiping. The results afforded from these exposures generally agreed with similar studies generated in the laboratory, where two-component (2K) urethane crosslinked systems exhibited improved performance. In these studies, all basecoats were generally solventborne melamine crosslinked 1K acrylic/polyester systems, pigmented to be black in color. Exceptions to this were twofold. One panel was composed of a waterborne (WBBC) urethane dispersion black basecoat. This system utilized the same poly(urethane) (PUR) clearcoat system C. It was apparent in this case that the waterborne basecoat drastically decreased the etch performance. The other exception consisted of the same solventborne basecoat described above, but where the clearcoat was a solventborne 1K silane modified acrylic cured with melamine. This system showed comparable performance to some of the 2K PUR systems. These results varied slightly to those conducted in laboratory experiments, where silane systems performed poorly.

Recent attempts to correlate laboratory acid etch results with the field performance has resulted in an "accelerated acid test" protocol. (26) In this procedure, an accelerated weathering device was modified into a new model to accommodate critical parameters identified from environmental data. The critical test parameters included acidic solution composition, temperature, humidity, UV radiance, radiant heating, and specimen orientation. The newly developed procedure showed excellent correlation to field etch results. Table 1 displays the experimental conditions utilized in the BASF/Q-Sun technique to correlate to field observations.

Correlations between the field exposures and the BASF/Q-Sun technique were then made with several OEM clearcoats (Table 2). As shown in the table, excellent correlation was found to exist between the two procedures. This experimental procedure will allow for faster development of etch resistant coatings.

Ultraviolet Light Resistance

Flexible automotive plastic coatings are formulated for outdoor weathering protection in a very similar fashion to that utilized for nonflexible coatings used on steel. Hindered amine light stabilizers and ultraviolet light (UV) absorbers are formulated into the basecoat and clearcoat to provide adequate protection from sunlight. Flexible coatings utilized over plastic, however, are generally lower in modulus, possess a lower glass transition temperature, and are placed over a more porous, low modulus substrate. All of these factors can influence the tendency of the stabilizer package to migrate, either into the substrate or out of the coating system entirely, resulting in potential loss of UV protection.

Work done by Haacke, (27) Andrawes, (28) and Cliff (29) have shown that nonreactable stabilizers migrate into plastic substrates in model studies where clearcoat is applied directly over the plastic and cured at normal conditions as well as total basecoat/clearcoat systems applied over primed thermoplastic olefin (TPO) substrates. In addition, weathering studies on these coating systems have shown that the most significant migration occurs during weathering exposure rather than at the time of application and cure. Significant (almost complete) depletion of nonreactable UV absorbers and HALS (hindered amine light stabilizers) from the topcoat into the TPO substrate was seen after only a few thousand hours of Xenon exposure. (30)

The above referenced studies have shown that coating type, substrate type, inclusion of basecoat, and reactability of stabilizers affect the migration of UVAs and HALS species and, hence, the performance of these coatings over plastics. Cliff, et al., (31) have demonstrated that characteristics of stabilizers such as reactability, primary versus secondary hydroxyl functionality, reactable UVA versus HALS, effect of structural variations in UVAs and HALS species, and basecoat stabilization can affect the ultimate weathering performance of the coating systems. They demonstrated a direct relationship between migration of light stabilizers and performance of stabilized coatings.

One of the difficulties in assessing the relative migration of light stabilizer packages lies in the lack of analytical techniques available for determination of light stabilizer location and level. This is especially true for reactable light stabilizers, which cannot be easily extracted and analyzed, as well as for HALS in general, which undergo chemical transformations as part of their stabilizing activities during weathering. (32)

As shown in Figure 10, the gradient of light stabilizer movement within the coating can be determined at five micron intervals by measuring the absorbance of the film at various wavelengths. By assessing the stability of the system to this migration (as evidenced by the loss of absorbance), the correct light absorber package for the plastic or paint/plastic system can be devised.

Of the variables evaluated by Cliff, (30) which included UV absorber reactability, HALS reactability, and basecoat stabilization, it was demonstrated that UV absorber reactability had the most profound effect on coating performance as evaluated by Xenon arc accelerated weathering. Reactable UV absorbers significantly outperformed nonreactable UV absorbers. It was also found that primary hydroxyl functional, 100% reactable UV absorber afforded the best performance. HALS reactability alone also was shown to have a significant positive effect on performance in systems without basecoat stabilization. These results supported the conclusions of previous studies that very little migration of stabilizers from topcoat to TPO substrate occurs during initial cure, and that stabilizer migration occurs chiefly during subsequent exposure. The results also support the assumption that loss of stabilizer from the topcoat correlates directly to loss of weathering performance.

Scratch Resistance

Scratch resistance of plastics has become an increasing area of emphasis in the automotive arena since the introduction of mold-in-color substrates on the interior of the vehicle. Most scratch methodologies (33-37) used today have been developed for metals and the scratch performance resulting is generally based on metallic material parameters, such as strain hardening.

Polymers have a very different set of properties that have to be taken into account in the definition of the scratch parameters. A number of research studies have recently focused on the scratch behavior of polymers, taking into account the more complex rheology of these materials. In particular, when testing polymers, the effects of probe geometry, scratch speed, and sample temperature can affect the actual scratch mechanisms undergone by the surface. Also, metal material parameters that have been used to characterize scratch resistance may lose their significance for polymers because of the interaction of various mechanisms. First, the quantitative analysis of plastic deformation becomes more difficult as relaxation effects take place, which may reduce or erase any ductile deformation that may have occurred during the scratching process. Second, the transition between ductile behavior and brittle damage has been extensively studied in the literature, as fracture mechanisms usually generate the most visible features on a surface. It has usually been characterized via the load applied on the probe at the point where the first fracture event is occurring. For specific cases, the use of the "critical load" is sufficient and can be related to field performance. Recent results at various scratch speeds indicate that the critical load does not solely characterize the fracture toughness of the material. Jardret reported that for PMMA, depending on the shape of a conical indenter (various values of cone included angle and tip radius), the critical load would vary depending upon scratch speed. (38) The authors showed that visco-plastic behavior was interacting with the toughness of the material to determine the load under which the material would fracture.

[FIGURE 10 OMITTED]

[FIGURE 11 OMITTED]

Scratch resistance of plastics was monitored on unpainted, filled mold-in-color TPO samples. Figure 11 displays the scratch imparted by a 1-mm diameter stainless steel probe at a speed of 100 mm/sec at room temperature as analyzed by an interferometer. The left micrograph depicts the scratch as viewed in three-dimensional topographic interference microscopy. The scratch depth is shown in the right side of the figure. As can be seen in the depth of scratch analysis, as material is removed from the scratch "ditch" it may be plowed into "shoulders" on either side of the scratch "ditch." This type of behavior is not always the same for all plastic materials. Often, material is simply cavitated from the ditch and may be fractured away from the sample, resulting in a ditch with no shoulders.

[FIGURE 12 OMITTED]

The depth of the scratch, as shown in Figure 11, taken as the area of the "ditch" as would be deduced from the unperturbed surface profile, is evidenced by the area included from below the "dotted" line into the "ditch area" (not as would be deduced as the area from the "shoulder" into the ditch).

The effect of grain structure on the scratch resistance of mold-in-color and painted TPO and poly(carbonate)/acylonitrile-butadiene-styrene (PC/ABS) copolymer materials scratched with a 1-mm diameter three-finger helical probe at a velocity of 0.5 mm/sec and an elevated temperature of 29.4[degrees]C is shown in Figure 12. The paint utilized in the study is a water-based urethane acrylic lacquer modified with a chlorinated poly(olefin) to aid in adhesion.

Grain is often added to a substrate to effect a topological profile that mimics other natural materials, such as leather or fabric. The grains listed in Figure 12 differ in their profiles, where the technical grain asperities are generally close-packed, geometric designs, smooth with no surface asperities, and the animal grain asperities are wider and shallower. As can be viewed in the figure, the technical grains on unpainted TPO generally have the highest scratch resistance, followed by lower performance of the smooth and animal grains (which perform similarly). When painted, however, the TPO materials, regardless of grain, perform poorly. Painted PC/ABS performs very well, regardless of grain, outperforming even the best mold-in-color TPO.

The effect of grain on scratch resistance is confounded. Grain asperity differences may result in different contact areas of the scratch probe on the surface. The total energy exerted on the surface of the plastic by the scratch probe is dependant on the total contact area and, hence, the grain asperity. If the force exerted exceeds the fracture toughness of the material, a fracture results.

The variance of the painted and unpainted PC/ABS and TPO materials may be a result of modulus differential (PC/ABS is harder and may dissipate applied stress better) or differential paint adhesion. Although the PC/ABS materials performed better in all grains analyzed, no variance in adhesion could be discerned between the TPO and PC/ABS in typical adhesion tests like cross-hatch or humidity exposure.

[FIGURE 13 OMITTED]

To determine whether paint adhesion could potentially affect scratch resistance, two types of paint were applied to TPO and the resultant scratch performance was monitored. As shown in Figure 13, identical smooth TPO plaques were painted with one of two systems: the first system consisted of a flame pretreated substrate to which the same water-based urethane acrylic lacquer modified with a chlorinated poly(olefin) described above was applied; the second panel was not flame treated and only painted with the same paint. The plaques were then subjected to scratch testing with a 1-mm diameter stainless steel probe run at 100 mm/sec at room temperature. As can be viewed in the figure, the flame pretreated panel exhibited a different fracture pattern that occurred at higher applied fracture stress (15N vs. 6N force) than the non-flame treated panel. This observation parallels the cohesive strength argument made for the "chip" and "gouge" testing described above. It appears that the top layers of a plastic composite, whether paint/plastic or plastic weak boundary layers within a plastic, control the subsequent cohesive strength of that material. As the cohesive strength of the layers increases, either by increased adhesion of the paint or increased cohesion of the plastic, the resultant surface damage resistance appears to increase.

SUMMARY AND FUTURE TRENDS

Lightweight, high-strength materials (including polymer-matrix composites) will be the focus for material development in the automotive industry for the next several years. Increased fuel efficiency through reduction in a vehicle's weight without sacrificing safety continues to be a major emphasis of the U.S. Department of Energy and the U.S. Council for Automotive Research (USCAR).

While cost reduction is the biggest challenge facing the automotive design and engineering communities, customer focused innovation that offers final cost-benefit value in vehicles appears to have gained importance, according to a 2005 Society of Automotive Engineers' survey. While polymeric content in the average North American light vehicle rose slightly in 2004 from the previous year, from 285 to 291 pounds, (39) significant improvements in strength, durability, oxidative stability, and weatherability are required to increase that level.

Improved scratch, chip, and gouge resistance, achieved through the use of films, ceramic coatings, and other nano-filled materials, are constantly being researched to deliver enhanced durability of plastics and plastic composites.

The use of bio-based materials, such as poly(lactic acid), soybean oil derived materials, and the like are being investigated to cut our dependence on petroleum-based materials.

End-of-life vehicle requirements, driving the depletion of heavy metals in automotive production and encouraging the use of recyclate, will also drive the need for improved processing and oxidative stability.

Complexity reduction, through modularization and creative fastening designs, will be invoked to increase efficiency in plants. Total plant processes will be studied to understand the role of processing parameters on end-use performance of mold-in-color and painted plastics. Process "robustness" must be increased to deliver quality products quickly, that are right the first time. Reduction of in-plant scrap is a mandate!

Finally, driving the increased performance in painted and unpainted plastics are the specifications. Testing specifications must be geared to understand the "root cause" of chipping, scratch, weathering, and the like. Without knowing mechanisms, one cannot increase performance through polymer modification or process improvement. One must ascribe to total system performance.

For sustainable development, the entire product chain must be optimized, from the resin costs through the molding and the customer demands. There is a great opportunity to turn around a tradition of commoditization, achieved only through raw material cost reduction, to understanding the total cost of the product. Focused innovations and increased value-chain collaboration must be the wave of the future.

References

(1) http://www.wmrc.com/press_release/20030212-1.pdf.

(2) Cannon, K., Paint Coat. Ind., p. 80, June (2005).

(3) Clemens, R.J., Batts, G.N., Lawniczak, J.E., Middleton, K.P., and Saas, C., Proc. XIXth Conf. Org. Coat. Sci. Tech., Athens, Greece, 105, 1993.

(4) Grundke, K. and Jacobasch, H.J., Farbe und Lacke, 98, 934 (1992).

(5) Aoki, Y., J. Polym. Sci.: Part C, 23, 855 (1968).

(6) Prater, TJ, Kaberline, S.L. Holubka, J.W., and Ryntz, R.A, "Examination of the Distribution of TPO Adhesion Promoter Material in a Painted TPO System," J. COAT. TECHNOL., 68, No. 857, 83 (1996).

(7) Waddington, S. and Briggs, D., Polym. Commun., 32 (16), 506 (1991).

(8) Ryntz, R.A., Xie, Q., and Ramamurthy, A.C., "Effects of Coating Solvents on the Morphology of Thermoplastic Polyolefins (TPO)," J. COAT. TECHNOL., 67, No. 843, 45 (1995).

(9) Ryntz, R.A., Prog. Org. Coat., 27, 241 (1996).

(10) Li, L., Sosnowski, S., Chaffey, C., Balke, S., and Winnik, M., Langmuir, 10 (8), 2495 (1994).

(11) Komatsu, Y., Kamimura, J., Aoki, O., Chung, D., and Wiseman, M., SAE Technical Paper #940187 (1994).

(12) Fujimoto, F., Paint and Resin, 36, February (1986).

(13) Ryntz, R.A., Advanced Coating Technology Conference Proceeedings, Engineering Society of Detroit, Detroit, MI, April 1997.

(14) Ryntz, R.A. and Buzdon, B., Prog. Org. Coat., 32, 167 (1997).

(15) Fujiyama, M. and Kimura, S., Kobunshi Kobunshu (English Edition), 4 (10), 777 (1975).

(16) Kantz, M.R., Newman, H.D., and Stigale, F.H., J. Appl. Polym. Sci., 16, 1249 (1972).

(17) Fitchmun, D.R. and Newman, S.J., J. Polym. Sci., Part A2, 8, 1545 (1970).

(18) Ryntz, R.A., Everson, M., and Pollano, G., Prog. Org. Coat., 31, 281 (1997).

(19) Buzdon, B. and Ryntz, R.A., "Friction Induced Paint Damage: The Role of Coating Attributes," paper presented at SAE Conference, Detroit, MI (1996).

(20) Ramamurthy, A.C., Ryntz, R.A., and Mihora, D., "Thermal and Impact Induced Stress Failure in Painted TPO: The Role of Surface Morphology," J. COAT. TECHNOL., 67, No. 840, 35 (1995).

(21) Ryntz, R.A. and Buzdon, B., SAE Technical Paper #950801 (1995).

(22) Ryntz, R.A., Ramamurthy, A.C., and Holubka, J.W., "Stone Impact Damage to Painted Plastic Substrates," J. COAT. TECHNOL., 67, No. 842, 23 (1995).

(23) Ryntz, R.A., Proc. SPE TPO in Automotive, Dearborn, MI, 2003.

(24) Fisher, T. and Uhlianuk, P., Akzo Internal Research Report, 1989.

(25) Ryntz, R.A. and Parker, J., Ford Motor Company unpublished results, 1994.

(26) Quill, J., Boisseau, J., Campbel, D., Wurst, W., and Brennan, P.J., Proc. 32nd Annual International Waterborne, High-Solids, and Powder Coatings Symposium, New Orleans, LA, p. 308, 2005.

(27) Haacke, G., Andrawes, F.F., and Campbell, B.H., "Migration of Light Stabilizers in Acrylic/Melamine Clearcoats," J. COAT. TECHNOL., 68, No. 855, 57 (1996).

(28) Andrawes, F.F. et al., Anal. Chem., 70, 3762, 1998.

(29) Cliff, N., Yaneff, P., and Adamsons, K., Fourth International Coatings for Plastics Symposium Proc., Troy, MI, 2001.

(30) Cliff, M. et al., Proc. 30th Annual International Waterborne, High-Solids, and Powder Coatings Symposium, New Orleans, LA, p. 29, 2003.

(31) Cliff, N., Kanouni, M., and Peters, C., Proc. 8th International Coatings for Plastics Symposium, Troy, MI, June 2005.

(32) Turro, N., Die Angewandte Makromolekulare Chemie, 232, 165 (1995).

(33) Jardret, V., Lucas, B.N., Oliver, W., and Ramamurthy, A.C., "Scratch Durability of Automotive Clear Coatings: A Quantitative, Reliable, and Robust Methodology," J. COAT. TECHNOL., 72, No. 907, 79 (2000).

(34) Lin, L. and Blackman, G., Proc. Adv. Coatings Technology Conference, International Body Engineering Conference, SAE/ESD, Detroit, MI, 1998.

(35) Courter, J.L. and Kamenetzky, E.A., "Micro- and Nano-Indentation and Scratching for Evaluating the Mar Resistance of Automotive Clearcoats," presented at the 5th Nurnburg Congress on Creating Advances in Coating Technology, Nurnburg, Germany, 12 April 1999.

(36) Briscoe, B.J., Evans, P.D., Pelillo, E., and Sinha, S.K., "Scratching Maps for Polymers," Wear, 47, 200 and 137, 1996.

(37) Shen, W., Ji, C., Jones, F.N., Everson, M.P., and Ryntz, R.A., Polym. Mater. Sci. Eng., 74, 346 (1996).

(38) Jardret, V., Proc. Athens Coatings Conference, Athens, Greece, July 2002.

(39) American Plastics Council 2004.

2005 Joseph J. Mattiello Memorial Lecture

The Joseph J. Mattiello Memorial Lecture, presented annually by the FSCT, commemorates the contributions of Joseph J. Mattiello, who served as President of the organization from 1943-44. Dr. Mattiello was instrumental in expanding the application of the sciences in the decorative and protective coatings fields. The Mattiello Lecturer, chosen from among those who have made outstanding contributions to science, is selected to present a paper on a phase of chemistry, engineering, human relationships, or other sciences fundamental to paint, varnish, lacquer, or related protective or decorative coatings. Dr. Ryntz presented the Mattiello Lecture at the Opening Session of the FSCT's Annual Meeting, November 6-9 in Las Vegas, NV.

Rose A. Ryntz

Dr. Rose A. Ryntz is Senior Manager for Advanced Material and Fastener Engineering, as well as Staff Technical Fellow (technical scientist position) with Visteon Corporation, Dearborn, MI. Dr. Ryntz is recognized as one of the world's leading experts in the area of automotive plastics coatings and has developed new techniques to study paint on plastic performance, including scratch and gouge resistance.

Dr. Ryntz earned a B.S. in Chemistry from Wayne State University, a Ph.D. in Organic Polymer Chemistry from the University of Detroit, and an M.B.A from Michigan State University.

In 1983, Dr. Ryntz began her career with Dow Chemical Company as a Senior Research Chemist. She joined the Mt. Clemens Paint Plant of Ford Motor Company in 1985 and moved to DuPont Automotive Coatings following their purchase of Ford's paint facility. After joining Akzo Coatings Inc. in 1989, she was appointed Technical Director for Plastics and Industrial Finishes. In 1992, Dr. Ryntz rejoined the Ford Motor Company, working as a Senior Technical Specialist in the Plastics & Trim Products Division (Visteon, Dearborn, MI).

[ILLUSTRATION OMITTED]

Dr. Ryntz is an active member in the coatings community. Recently named President of the Federation of Societies for Coatings Technology (FSCT), she has served the organization in numerous capacities, including Past Chair of the Professional Development, Annual Meeting Program, and Industry Relations Task Force Committees. Dr. Ryntz was a member of the FSCT Events Steering Committee, the Technical Advisory, Operating, Nominations, and Paint Industries' Show Committees, and was a Trustee of CIEF. A member of the FSCT Publications Committee, she also serves on the Editorial Review Board of JCT Research and the Advisory Board of JCT CoatingsTech.

Dr. Ryntz was Technical Chair for the Detroit Society of Coatings Technology from 1988-1994. In addition, she has served as an adjunct professor at the University of Detroit/Mercy, the University of Wisconsin, Kent State University, and the University of Southern Mississippi. She also served as Chair of the Younger Chemists Steering Committee for the American Chemical Society from 1988-1990.

An author of over 75 papers and 25 patents in the paint and plastics field, Dr. Ryntz has also written one book, Adhesion to Plastics: Molding and Paintability and edited two books, Plastics and Coatings: Durability, Stabilization, and Testing and Coatings of Polymers and Plastics. She is co-editor of the recently published book, Service Life Prediction: Challenging the Status Quo.

Dr. Ryntz has received a number of awards including the 2000 George B. Heckel Award, the FSCT's highest honor. She was awarded first place in the 2000 FSCT Roon Foundation Award Competition, the 2003 Roy W. Tess Award from the Division of Polymeric Materials: Science and Engineering (PMSE) of the American Chemical Society, and the 2004 Women's Automotive Association International's Professional Achievement Award. She is also the recipient of the Henry Ford Technology Award and several customer-driven quality awards from the Ford Motor Company, as well as the Gold Award and the Outstanding Leadership Award from the Engineering Society of Detroit for contributions to advancing the knowledge of science and engineering. Dr. Ryntz is listed in Strathmore's Who's Who in the World.

Rose A. Ryntz -- Visteon Corporation

Presented at the 83rd Annual Meeting of the Federation of Societies for Coatings Technology, November 6-9, 2005 in Las Vegas, NV.

* 401 Southfield Rd., A228, Dearborn, MI 48120.

Table 1 -- Summary of Conditions in Acid Etch Testing

Property            Field Observations            BASF/Q-Sun Technique

Temperature         70-80[degrees]C               80[degrees]C
Rainfall            10-15 significant events      13 Acid spray events
Dew                 Evening dew                   Dark step water spray
Relative humidity   Typically 80% or higher       80% Throughout the
                                                    test
Orientation         0-5 degrees                   0 degrees
UV light spectrum   Variable throughout the test  Noon summer sunlight
UV light intensity  Variable throughout the test  Constant

Table 2 -- Jacksonville 2001 vs. BASF/Q-Sun Etch Ratings Of Various OEM
Clearcoats

                                                  Jacksonville
Clearcoat System  420 Hour BASF/Q-Sun Rating (a)  Rating (a)

1                  5                               5
2                  5                               6
3                  6                               4
4                  6                               5
5                  6                               6
6                  8                               6
7                 10                               9
8                 10                              10
9                 10                              10

(a) Rating System: 0-3 = very slight etch only noticed by trained
observer; 4-6 = slight to moderate etch noticed by untrained observer;
7-10 = etch severe enough to cause complaint by vehicle owner.