The Mitsubishi Petrochemical Co. (MPC) has principal research centers at Yokkaichi and at Tsukuba. The former is devoted to market-oriented research and the latter to long-term basic research, including biotechnology. The company had sales of approximately $3.7 billion dollars in 1992 in five major areas: (1) industrial chemicals (45%); (2) plastics (45%); (3) fine chemicals (e.g., components of consumer products); (4) electronic components; and (5) bio-related products (especially L-aspartic acid, fungicides, and amino acids). Their plastic products are of three principal types: (1) polyolefins, especially polypropylene; low-density, linear low-density, and high-density polyethylene; and ethylene-vinyl acetate copolymers; (2) specialty polymers, including propylene-based thermoplastic elastomers, poly(acrylic acid), polymers for adhesives, and conducting polymers; and (3) engineering plastics, especially fiber-reinforced PET and poly(phenylene ether)-nylon blends.
The major market area for MPC plastics is in the company's polyolefins films (more than 50% of MPC's polyethylenes are sold as films). MPC has a particularly strong capability for producing cast films and oriented films. A large market for the company's PE films is in greenhouse covers. The company also has substantial sales in Japan of PE films for nondegradable, mulch film applications. Japanese farms are relatively small, so it is not too inconvenient for them to remove the mulch films after the growth season and dispose of them in landfills or by incineration. MPC has evaluated photodegradable films for that purpose. However, such materials were found to be unsuitable because pieces of the disintegrated film remained in the soil and were considered to be an environmental hazard. The company takes the same view of PE films, which have prooxidants designed to degrade by oxidation. MPC agrees that biodegradable mulch films would be very desirable if they had acceptable mechanical properties and did not cost substantially more than normal PE films. The company estimates that a product that was up to 50% more in price than current nondegradable mulch films would be acceptable to the farmers because of the saving on labor costs.