High-Performance, Low-VOC Waterborne Coatings

This page updated December 1, 2006.

Southwest Texas State University

High-Performance, Low-VOC Waterborne Coatings

CARB Grant Number ICAT 02-2


The statements and conclusions in this Report are those of the grantee and not necessarily those of the California Air Resources Board. The mention of commercial products, their source, or their use in connection with material reported herein is not to be construed as actual or implied endorsement of such products.

Project Summary
This project was a collaborative effort to produce prototype high-performance drum and wood coatings with a target of 100 g/L VOC or less from new hyper-branched vegetable oil polyol phosphate esters (POLYOL) and give a commercial application demonstration that compares the prototype paints with existing paints for VOC and performance. POLYOL can be used as a waterborne short oil alkyd type resin or as a reactive co-resin with short oil alkyds and polyester resins for metal bake coatings with good adhesion and low VOC. It can also be used in ambient cure polyurethane coatings for wood.
Texas State University developed hyper-branched high performance phosphate ester polyol resin technology for reducing VOC in alkyd and other coatings to meet 2006 limits. The innovative aspect of the new resins is their hyper-branched technology combined with water dispersibility and corrosion resistance via the phosphate ester groups. It is innovative in that the hyper-branched resins give similar performance to current commercial linear resins at one-tenth the viscosity by reducing polymer chain entanglement. This innovation is important in that it allows waterborne and solvent based alkyd paints to achieve conventional performance at unconventionally low VOC. The unconventional use of the phosphate ester for dispersion reduces the need for surfactant and the phosphate dispersing group reacts with metal substrates to improve adhesion and improve corrosion resistance of the coating.
The bio-based hyper-branched alkyd technology should, at high production volume, provide lower cost, equivalent performance, and lower VOC than is provided by commercially available alkyd technology. The new waterborne technology has the capability of producing high performance short oil alkyd-type paints that are compliant with projected emission standards for 2006. It performed in the ICAT funded demonstration project as expected and met performance requirements at VOCs of 100 g/L and less using commercially available ingredients.
Collaborators were Arkema, Precision Coatings, Dunn-Edwards, National Ink, Niemann & Associates, Valspar, Cook Composites and Polymers, Sherwin-Williams, and Rohm & Haas. Precision Coatings' qualified lab prepared POLYOL3.5 from Texas State and from Arkema. Precision Coatings then qualified a 10-gallon pilot-scale preparation of POLYOL3.5 from Arkema.
Precision Coatings then conducted a demonstration of the new 174 g/L low VOC POLYOL based black container coating on April 11, 2006, at a customer plant in the South Coast Air Quality Management District. Five gallons of black POLYOL formulation were used to purge the paint lines and spray paint three drums on the commercial line. The three drums were flash dried, baked, cooled, and removed from the line for visual inspection and testing.
The coatings had good flow, good gloss, good adhesion, and good MEK solvent resistance. The drums had some streaking, possibly due to inadequate wetting. This occurred last year on plant start-up with the regular coatings and was corrected by reformulation. Precision Coatings intends to commercialize the coatings.

Funding Source

Funding Amount


ICAT

$  99,324

Grantee

$  44,000

United Soybean Board and
Paint Companies

$293,550




ICAT Funded Projects

preload