CEH Report

Table of Contents

Abstract

Isophthalic acid is a colorless crystalline solid. It is used as an intermediate primarily for unsaturated polyester resins and alkyd and polyester coating resins; other applications include use in aramid fibers, as a component of copolyester resins and in high-temperature polymers. At one time, some producers sold isophthalic acid/terephthalic acid mixtures, which contain from less than 1% to 30% terephthalic acid. In recent years, however, the trend has been toward nearly pure isophthalic acid with a purity of >99.8%. This material is called purified isophthalic acid or PIA.

The following pie chart shows world consumption of isophthalic acid:

Currently, there is significant global overcapacity for isophthalic acid, with sufficient spare capacity for the next five years. However, there have been several recent announcements regarding new plant construction.

• In 2007, Russia's Zavod novykh polimerov Senezh announced plans to build a 6 thousand metric ton-per-year plant to service the growing market for PET bottle resins.
• In 2008, Mossi & Ghisolfi (M&G), the largest global producer of PET bottle resins, announced plans to begin manufacture of PIA at its Paulínia, São Paulo, Brazil site, which also makes PET fibers and bottle resins. The output will be sent to other M&G locations around the world. Expected start-up is by the end of 2009.
• In 2010, Sinopec Beijing Yanshan is expected to complete an expansion that will add 15 thousand metric tons per year of capacity.

PIA has three major uses:

• PET copolymer, which is used in bottle resins and to a much lesser extent, for fibers. PIA reduces the crystallinity of PET, which serves to improve clarity and increase the productivity of bottlemaking manufacture.
• Unsaturated polyester resins, where the addition of PIA improves thermal resistance and mechanical performance, as well as resistance to chemicals and water.
• Polyester/alkyd surface coating resins, where PIA increases resistance to water, overall durability and weatherability.

The best prospects for growth for PIA are in the developing areas of Asia. Consumption in China is expected to increase by about 13% per year, mainly as a result of increased production of PET bottle resins, which is forecast to grow at about 15% per year through the forecast period. Other markets such as unsaturated polyester resins and surface coatings should grow at an average of 10–12% per year. PET bottle resins are also expected to grow in countries like the Republic of Korea and Taiwan, but to a lesser extent.