Cyclopentadiene Market

By Shen Guiying, China National Chemical Information Centre

During thermal cracking of Petroleum based raw materials to get ethylene, by-product fractions C5 and C9 are obtained, and these fractions are further separated to form cyclopentadiene. Cyclopentadiene can self-polymerize to gain dicyclopentadiene (DCPD at room temperature. Before use, the dicyclopentadiene can simply be heated to convert into cyclopentadiene. Therefore, the product in the market is dicyclopentadiene. In China, cyclopentadiene is used to make unsaturated polyester resin (UPR), petroleum resin, ethylene propylene diene monomer rubber (EPDM), cyclic olefin copolymers (COC), polycyclopentadiene, certain fine chemical products, etc. The consumption pattern is shown in Figure 1.

UPR

UPR is one of the main thermosetting resins, usually obtained by stepwise polymerization from dicarboxylic acid and dihydric alcohol. Since the 1980s, the United States and Western Europe have studied the modification of UPR by using cyclopentadiene instead of phthalic anhydride. During the first 10 years of this century, cyclopentadiene commonly replaced phthalic anhydride to modify UPR used in the manufacture of bathtubs and pleasure boat hulls in the United States. In Japan, such modified UPR is also used in the electronic field. Many companies produce UPR modified by cyclopentadiene, such as DSM Composite Resins AG in Western Europe, TOTAL Cray Valley in France and Reichholdin the United States. The purity of cyclopentadiene in 75%~83 % can reach the requirements during the production of ordinary UPR. Only a small amount of special-purpose UPR requires 94% pure cyclopentadiene.

Petroleum resin

Petroleum resins are widely used in coatings, rubber tackifier, waterproofing materials, melt adhesives, flooring, textiles, painting materials, etc. The purity of cyclopentadiene used to make petroleum resin is not high, generally 75%~83%.
In China, petroleum resin polymerized from dicyclopentadiene with content of around 80% is known as DCPD resin, which is mainly used in paint, ink, synthetic rubber, etc. Globally, petroleum resin manufacturers include ExxonMobil, Neville and Eastman. DCPD resin units have been set up by a number of enterprises in China.

EPDM

EPDM is mainly used in the automotive field in making car body, chassis and tires. Other uses include rigid waterproof roofs, oil field chemicals, wire and cable insulation, etc.
Ethylidenenorbornene (ENB) has become the most widely used third monomer in the synthesis of EPDM, due to curing speed and high yield.
DCPD reacts with 1, 3- butadiene to produce vinyl norbornene, and then ENB is prepared by further isomerization. The amount of ENB used in EPDM is 3%~12%. Jilin Petrochemical Co., Ltd. Constructed China’s first EPDM device; its production capacity is 45 kt/a. From the end of 2014 to the first quarter of 2015, a 75 kt/a device of Sinopec Mitsui Chemicals Co., Ltd., a 50 kt/a device of Ningbo SK and a 160 kt/a equipment of LANXESS (Changzhou) were put into operation.

COC

High purity cyclopentadiene (94%) is reacted with ethylene to synthesize norbornene, and polymerization of norbornene and cyclopentadiene can produce cyclic olefin COC. At present, COC is widely used in the manufacture of various optical lens prisms, car headlights, liquid crystal display (LCD) optical films, contact lenses, etc. In addition, COC resin has a very low dielectric constant. It can be used to manufacture electronic and electrical components. Because of its good moisture proof property, it can also be used to make packaging materials for medicines and foods. The main manufacturers of COC include Celanese Ticona, Japan Zeon, Japan Synthetic Rubber and Mitsui Chemicals.

PDCPD

PDCPD is a transparent resin with excellent impact resistance, low density and convenient molding performance, mainly used for reaction injection molding (RIM) products with excellent mechanical performance and complex shape, sheet molding compounds (SMC) and spray-forming glass fiber reirforced materials. RIM product shave excellent processing performance, can replace steel plate, cast and glass fiber reinforced plastics, are used in making leisure travel vehicles, agricultural vehicles, engineering vehicles, medium truck, heavy truck parts, as well as material conveying machinery, auto repair parts, medical equipment parts, and in the corrosion-control field as battery coversin chlor-alkali equipment.The market for PDCPD is growing.
Since 2006, China has studied and produced PDCPD, but produced only a little.

Fine chemical products

Hexachlorocyclopentadiene by the reaction of cyclopentadiene and chlorine is a versatile intermediate, not only can be used in the synthesis of flame retardant chlorendic anhydride and Dechlorane Plus, also in the synthesis of the pesticide Pentac, etc. Dicyclopentadiene dioxide, dicyclopentadiene diepoxide and dicyclopentadiene dicarboxylic acid made from cyclopentadiene are intermediates used in synthesizing surface coating resin. Cyclopentadiene is also used for the synthesis of metallocene. 2- chloro -5- chloromethylpyridine (CCMP), prepared by the reaction of cyclopentadiene and propionaldehyde, is a synthetic intermediate used for synthesis of various pesticides, such as imidacloprid, acetamiprid, etc.
In 2016, the net profit of China’s specialty chemicals industry was RMB150.1 billion, accounting for about 29.6% of the total profits of the chemical industry.
The products made from cyclopentadiene are more special chemicals with high added value. The use of cyclopentadiene in making UPR and fine chemical products is mature, and technology for its use in making COC and PDCPD is still in development. Cyclopentadiene applications will likely develop rapidly in making hydrogenated petroleum resins, petroleum resins and EPDM in the future.