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Polyester polyols are macroglycols that are prepared by the condensation of
a glycol and a dicarboxylic acid or acid derivative. The three general types
of polyester polyols are manufactured from aliphatic diacids, aromatic diacids
and caprolactone. Polyester polyols react with polyisocyanates in the manufacture
of polyurethane polymers. The functionality, structure and molecular weight
of the polyester polyols are varied to produce a range of polyurethane products.
Polyester polyols compete with the more widely used polyether polyols; however,
polyester polyols are preferred in some applications such as rigid foam boardstock
because of their low cost and improved flame retardancy. In nonfoam polyurethane
markets, such as elastomers, coatings, sealants and adhesives, advantageous
properties include improved wear resistance, load bearing, heat aging, chemical
resistance and UV stability. Generally, caprolactone-based polyols are higher-performance
polyester polyols relative to other aliphatic polyester polyols, particularly
in nonfoam applications (pricing is higher than the typical aliphatic polyester
polyols based on adipic acid).
The polyester polyol industry is the least concentrated of the polyurethane
raw material product industries, and tends to have the least sophisticated
manufacturing processes and the lowest capital costs. In the United States,
the five largest producers represent 82% of total capacity, and in Western
Europe, China and Japan, the five largest companies each account for 62%, 52%
and 68% of the business, respectively.
The polyester polyol business is a global one. COIM is the largest world producer,
with plants in Italy, Brazil, Singapore and the United States. Stepan also
has production sites in several locations—the United States, Germany
and China.
World consumption is forecast to grow at an average annual rate of about 3.5%
from 2005 to 2010, from a low of 0.5% in Japan to a high of 5.6% in Central
and Eastern Europe.
The following pie chart shows world consumption of polyester polyols in 2005:
The market is shifting to China and other Asian countries (excluding Japan).
Asian consumption represents 42% of world demand.
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