Propylene Glycol Ethers Demand Increases Rapidly

By Zhang Jiaze   

Propylene glycol ethers are dihydric alcohol ethers. They are low-toxicity organic solvents with extensive applications. As their toxicity is lower than ethylene glycol ethers, the application scope and the consumption are making a constant expansion.

Low operating rate

The production of propylene glycol ethers in China started in the mid-1970s. Due to the problems such as inadequate raw material supply and outdated production technology, producers have small scale, high cost and poor product quality.   Major producers of propylene glycol ethers in China have a status as follows. Jiangsu Yangzhou Hualun Chemical Co., Ltd. uses the technology developed by Shanghai Research Institute of Petrochemical Industry, the unit has a capacity of 10 000 t/a and the output in 2004 was 5 000 tons. Shanghai Gaoqiao Petrochemical Co., Ltd. uses the technology developed by Shanghai Research Institute of Petrochemical Industry, the unit has a capacity of 3 000 t/a, the output in 2003 was 500 tons, the output in January 2004 was 150 tons and the production was then suspended due to the high price of propylene oxide. Jiangsu Yinyan Speciality Chemicals Co., Ltd. uses the technology developed by Zhejiang University and the unit has a capacity of 10 000 t/a.

Rapid consumption growth

The total capacity of propylene glycol ethers in China was 56 500 t/a in 2004 (20 000 t/a of the total for the co-production of ethylene glycol ethers and propylene glycol ethers), the output was around 19 000 tons, the net import amount was around 6 000 tons and the consumption was around 25 000 tons. Propylene glycol ethers in China are mainly used in coating, ink, cleaning agent and pesticide sectors. They can also partially replace ethylene glycol ethers in automobile braking fluids and anti-freezing fluids and therefore have a considerable potential market. It is expected that the average annual demand growth of propylene glycol ethers in China will be 19% from 2004 to 2010 and the demand will reach around 72 000 tons in 2010.

   1. Coatings

In the coatings sector propylene glycol ethers can be used as solvents, booster solvents and paint-removing agents. They are mainly used in the production of high-grade coatings and water-based construction coatings such as automobile paints, polyurethane paints and high-grade wood product paints. The output of coatings in China was 2.98 million tons in 2004, consuming around 8 000 tons of propylene glycol ethers.

   2. Ink

Propylene glycol ethers can be used as ink solvents and ink-removing agents. The output of inks in China was 237 800 tons in 2004 and the output of solvent inks accounted for 50 - 60% of the total. Due to the relatively high price, the consumption of propylene glycol ethers in the ink sector is still quite small today. The consumption of propylene glycol ethers in the ink sector was around 4 000 tons in 2004.

   3. Cleaning agents

Propylene glycol ethers can be used to prepare various concentrated cleaning agents. They can be used as ingredients of solvents or independently in industrial cleaning, de-rusting and brightening. Dihydric alcohol ether solvents used in the cleaning agent sector in China today are still based on ethylene glycol ethers and the proportion of propylene glycol ethers is relatively small. The consumption of propylene glycol ethers in the cleaning agent sector was around 6 000 tons in 2004.

   4. Electronic chemicals

Propylene glycol ethers can be used to prepare high-purity reagents for the cleaning of electronic devices and components. The consumption of propylene glycol ethers in the electronic chemical sector was around 2 000 tons in 2004 and the market demand in this sector was mainly satisfied by imports.

   5. Pesticides

Propylene glycol ethers can be used as solvents for pesticides, insecticides and herbicides and also as solvents for antitoxic agents of organophosphorus pesticides. The output of pesticides in China reached 870 000 tons (100%) in 2004. Pesticide formulations used in China are mainly emulsifiable concentrates. The need for the demand growth of propylene glycol ethers is therefore quite limited. The consumption of propylene glycol ethers in the pesticide sector was around 1 500 tons in 2004.

   6. Others

Propylene glycol ethers can also be used as solvents for cosmetics and perfumes and have the features of good solubility, mild odor and low toxicity. When they are used as ingredients of hydraulic braking fluids they can maintain the same phase with other ingredients in a wide temperature scope and small amounts of water are also allowed. The viscosity of propylene glycol ethers has little change with temperature and can therefore be used as important braking fluid ingredients that have small corrosion, good thermal stability and high boiling point and can remove air blockage and reduce evaporation loss. The consumption of propylene glycol ethers in other sectors was around 3 500 tons in 2004.    The raw material cost accounts for more than 90% of the production cost in propylene glycol ethers. The price of raw material propylene oxide has become the key factor for the investment return. Whether there is a stable supply of low-priced propylene oxide will produce a direct impact on the market competitive edge of propylene glycol ethers.