Non-Chromate/No-VOC Coating System for DoD Applications
Abstract
This document reports the results of a three year program funded by the Strategic Environmental Research and Development Program (SERDP) to research, develop, and demonstrate military coatings systems that are hexavalent chromium free and use primers and topcoats with ultra low volatile organic compound (VOC) content while maintaining high protection against corrosion and the environment, high durability, high performance, and low cost. Military coatings systems typically combine a pretreatment system applied directly to the substrate to protect against corrosion and enhance primer adhesion, an organic primer to further protect against corrosion and improve topcoat adhesion, and an organic topcoat to meet survivability and environmental durability requirements. Hexavalent chromium is typically used in the pretreatment or primer of military coatings. OSHA has reduced occupational exposure to hexavalent chromium from 52 g/m3 to 5 g/m3 by 2006 [1], which makes the application, and especially the removal of hexavalent chromium based coatings, extremely costly. Current primers and topcoats typically contain ~1.5-3.5 lbs/gal volatile organic compounds (VOCs). The EPA s Defense Land Systems and Miscellaneous Equipment (DLSME) National Emission Standard will further regulate hazardous air pollutants. As such, it is imperative to reduce VOC contents to nearly zero so that the next generation of military coatings not only have excellent performance, yet also meet or exceed current environmental rules and regulations. The trivalent chromium process (TCP) is the leading candidate to replace hexavalent chromium pretreatments in the military. Work has been done to modify and improve this process to increase performance and function well on a variety of substrates. Research has been done on the application of TCP to aluminum as a pretreatment and steel substrates as a wash primer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 2009
- Accession Number
- ADA608406
Entities
People
- John J. La Scala
- Steven L. Suib
Organizations
- United States Army Research Laboratory