Skip to main content

Structure/property relationships in flexible alkoxysilane automotive coatings


Flexible automotive coatings are susceptible to scratch and mar damage, especially during finishing and assembly operations. One-component (1K) flexible clearcoats exhibit very good scratch and mar resistance, but unfortunately suffer from poor durability and environmental etch resistance. Two-component clearcoats offer improvements in both etch and durability, but at the expense of scratch and mar. In this paper, the concept and properties of 1K flexibilized silane clearcoats for use on automotive plastics will be introduced and their structure/property relationships examined as they apply to scratch and mar.

The role of coating crosslink density, toughness, glass transition temperature (Tg), and surface profile on the scratch damage of coated plastic substrates will be described. In addition, a new scratch methodology, termed Scratcho, is utilized to determine relative scratch performance and is compared to conventional scratch resistance testing. Results to date indicate that hardness, as affected by the glass transition temperature, and crosslink density, as it contributes to higher essential work values, both affect resultant scratch propensity of the flexible coatings. The relative ranking of different coating systems employing alternate crosslinkers (e.g., isocyanate and melamine) is also presented and compared to the newly developed silane crosslinked coatings.

This is a preview of subscription content, access via your institution.


  1. Jardret, V., Lucas, B.N., and Oliver, W., “Scratch Durability of Automotive Clearcoatings: A Quantitative, Reliable and Robust Methodology,”Journal of Coatings Technology,72, No. 907, 72 (2000).

    Google Scholar 

  2. Shen, W.C., Jiang, B., and Jones, F.N., “Measurement of Mar Resistance and Study of Marring Mechanism of Polymer Coatings with Scanning Probe Microscope,”Journal of Coatings Technology,72, No. 907, 89 (2000).

    Article  CAS  Google Scholar 

  3. Ryntz, R.A., Abell, B.D., and Hermosillo, F., “Scratch Resistance Behavior of Automotive Plastic Coatings,” SAE International, Detroit, MI (1998).

    Google Scholar 

  4. Shen, W., Smith, S.M., Ye, H., and Jones, F.N.,Tribological Letters, 5, p. 75 (1998).

    Article  CAS  Google Scholar 

  5. Briscoe, B., Evans, P.D., Pelillo, E., and Sinha, S.K.,Wear, Vol. 200 (1998).

  6. Lucas, B., Oliver, W.C., Phass, G.M., and Loubert, J.L.,Proc. Mat. Res. Soc. Symp., Vol. 436 (1997).

  7. Jardet, V. and Oliver, W.C.,Proc. Mater. Res. Soc. Sym., 594, Boston, MA (1999).

  8. Ottviani, R.A., Iyengar, V., and Cheever, G.D.,SAE International Paper #970988, Detroit, MI (1997).

  9. Lin, L., Blackman, G.S., and Matheson, R.R., “A New Approach to Characterize Scratch and Mar Resistance of Automotive Coatings,” presented at 25th International Conference in Organic Coatings, Athens, Greece, July 1999.

  10. Gregorovich, B.V. and McGonigal, P.J.,Proc. Adv. Coat. Technol. Conf. ASM/ESD, p. 121 (1992).

  11. Haake, G., CYTEC unpublished results (1999).

  12. Ryntz, R.A., Britz, D., Pierce, R., and Mihora, D., “Measuring Adhesion to Poly(Olefins): The Role of Adhesion Promoter and Substrate,”Journal of Coatings Technology,73, No. 921, 107 (2001).

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations


Additional information

377 Fairall St., Ajax, Ont., L1S 1R7, Canada.

401 Southfield Rd., P.O. Box 6231, Dearborn, MI 48121-6231.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Yaneff, P.V., Adamsons, K., Ryntz, R.A. et al. Structure/property relationships in flexible alkoxysilane automotive coatings. Journal of Coatings Technology 74, 135–141 (2002).

Download citation

  • Issue Date:

  • DOI:


  • Melamine
  • Crosslink Density
  • Scratch Resistance
  • Ligament Length
  • Essential Work