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Pittsburgh -- The power of polyurethane topcoats first
debuted in the industrial maintenance and marine markets in the mid-1970s
as part of a corrosion protection system. Polyurethane topcoats have evolved
over the years into a versatile technology that can be formulated to create
low VOC coatings and productivity enhancing coatings, as well as long-lasting,
cost-effective coatings. However, recently there has been a call for ultra-high
weathering performance topcoats for applications such as sports facilities,
water tanks and bridges where coating systems are expected to provide
aesthetic appeal along with corrosion protection.
In a quest to explore whether current weathering performance specifications
for two-component polyurethane topcoats - such as SSPC Paint Specification
No. 36 - go far enough in defining the highest level of polyurethane
performance available for these demanding applications, Edward P. Squiller,
director, Specialty Coatings and Kurt Best, senior scientist, both of
Bayer MaterialScience (BMS) LLC, authored a paper: 2-Component Polyurethane
Topcoats - Formulating Variables Affecting Weathering Performance.
The authors discussed their paper at the recent 2008 Paint and Coatings
Expo.
There are many potential variables in typical corrosion protection topcoat
formulations that influence performance and application characteristics,
as well as the cost structure of the coating. These variables include
isocyanate index and resin selection, which play a major role in determining
the weatherability of the final product.
In their paper, the authors compare some key formulating variables of
aliphatic polyurethane topcoats and their resulting performance in an
accelerated weathering study. Aliphatic polyisocyanates traditionally
result in topcoats with much better outdoor weathering characteristics
versus aromatic polyisocyanates, and are primarily used in outdoor topcoat
applications in which gloss and color retention are required.
Through their research, the authors discovered that all of the polyurethane
topcoats tested met the highest performance level specified by SSPC Paint
Spec. #36 with regard to loss of gloss and yellowing, therefore concluding
that the topcoats are capable of achieving a much higher performance standard.
However, the authors caution against reading too much into just one accelerated
test method relative to other important considerations.
"This topcoat weathering study focuses on just one element of the
coating selection process for a corrosion protection coating application,"
said Squiller, who also noted that the coatings in the study have been
submitted for South Florida weathering and will be presented in the future
when the results become available. "One must also consider the application
characteristics of the paint, as well as cost and corrosion performance
as part of a multiple-coat system."
About Bayer MaterialScience LLC:
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 14,900 employees
at 30 sites around the world and 2006 sales of 10.2 billion euros from
continuing operations. Our innovative developments in coatings, adhesive
and sealant raw materials, polycarbonates, polyurethanes and thermoplastic
urethane elastomers enhance the design and functionality of products in
a wide variety of markets, including the automotive, construction, electrical
and electronics, household and medical industries, and the sports and
leisure fields. 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.
About Bayer Corporation:
Bayer Corporation, headquartered in Pittsburgh, is a
subsidiary of Bayer AG, an international health care, nutrition and innovative
materials group based in Leverkusen, Germany. In North America, Bayer
had 2006 net sales of 7.8 billion euros and employed 17,200 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 prevent and treat diseases; protect crops and enhance
yields; and advance automobile safety and durability.
This news release contains forward-looking statements based on current
assumptions and forecasts made by Bayer Group management. Various known
and unknown risks, uncertainties and other factors could lead to material
differences between the actual future results, financial situation, development
or performance of the company and the estimates given here. Th ese factors
include those discussed in our public reports filed with the Frankfurt
Stock Exchange and with the U.S. Securities and Exchange Commission (including
our Form 20-F). The company assumes no liability whatsoever to update
these forward-looking statements or to conform them to future events or
developments.
Source: Bayer MaterialScience
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