The Ministry of International Trade and Industry (MITI), which has been in the forefront of promoting the development of biodegradable plastics technology in Japan, estimated in 1994 that there was a potential worldwide market of 30 million tonnes/year for biodegradable plastics. It further estimated that a market worth yen 1,000 billion (US$9 billion) might develop from the technology.It was then evaluating to produce film from biodegradable plastics, and that 25% of Japan's plastics consumption could be substituted by biodegradable polymers.

In the event, these forecasts proved wildly optimistic, and the market remains tiny. According to the Biodegradable Plastics Society and the Global Environment Technology Department of the New Energy & Industrial Technology Development Organisation (NEDO), two agencies which have also been heavily involved in the national development drive, it amounts to about 1,000-1,500 tonnes/year. That in Japan itself accounts for barely 300 tonnes, and consumption here is smaller than in North America or Western Europe.

Nonetheless, Japan has a very strong position in biodegradable plastics technology and could be poised to take advantage, as and when the market takes off. As of late 1998, 10 companies in Japan offered 12 different brands of biodegradable plastics based on eight base materials: polylactic acid polycaprolactone, polybutylene succinate, polyethylene succinate, modified starch, starch alloys, cellulose acetate and polyhydroxy butyrate (PHB). Four are importers or local agents:

Cargill Dow Polymers is marketing it's polylactic acid-based EcoPla resins in Japan. Cargill Dow has made major commitments to the technology and looks set to dominate the global market in immediate future.

Novamont's starch-based material, mater-Bi, is marketed in Japan by Nippon Gohsei, which is also a manufacturer of polyvinyl alcohol for biodegradables and other applications. Mater-Bi has been used in transport packaging for electrical goods, agricultural mulch film and in composting trials.

EnviroPlastic, Planet Polymer's cellulose acetate-and polyethylene succinate-based are marketed in Japan by Mitsubishi and Nippon Shokubai under the trade names Lunare ZT and Lunare SE respectively.

Novon, whose ownership has changed several times, has been produced under license by Chisso since1994. Production of Navon's degradation additive, Degra Novon, is moving from the US to Japan this year.

Two Japanese producers - Showa Highpolymer and Mitsui Chemicals- are in some way ahead of the pack in terms of commercial development and can offer their products on a more or less global basis. Several others are poised for much larger commercial development at various times in the near to mid-term future, notably Daicel Chemical industries, Shimadzu, Mitsubishi Gas Chemical and Dainippon Ink & Chemical (DIC).

Showa Highpolymer is one of Japan's larger producers of unsaturated polyester, emulsions and styrenics. Its parent company, Showa, also owns Showa Denko, a major multi-line chemical company which co-operated with Showa High polymer in various areas of research and development of its main biodegradable plastics products, Bioinolle.

Showa Highpolymer has been working on biodegradable plastics since the mid 1980s and has supplied Bionolle in pellet form its 3,000 tonnes/year semi-commercial plant at Tatsuno since January 1994. By 1998, it had supplied samples to over 300 companies.

Showa Highpolymer has always been active in joint R&D work with other companies. This has included work with Toppan Printing (Japan's second largest printing company, a major manufacturer of food packaging) to develop a stretch blow- moulded Bionolle for bottles, and with Nihon Shokuhin Kako (a leading Starch producer) to develop film grade Bionolle with 50% starch for use in hollow mouldings, film, sheet, and mono-filament.

Bionolle is a thermoplastic aliphatic polyester. It is produced by the chemical reaction and polycondensation of glycol with dicarboxylic acids and others. There are two main grades: the 1000 series of polybutylene succinate homopolymers and the 3000 series of polybutylene succinate adipate homopolymers.

The main advantages claimed for Bionolle are its versatility and processability. It has reasonable resistance to oil and water, is stable in the atmosphere and has a processing range of 120°C-270°C. All of the grades can be offered in low and high melt flow ratios.

A very wide range of potential applications has been identified. They include: film (compostable rubbish bags, shopping bags, food packaging, wrapping film); lamination (paper lamination, bags, cups, containers); sheet extrusion (cards, can holders, food trays); mono-filament (fishing lines, nets, ropes); multi-filament (disposable nappies, napkins, textiles, non-woven cloth); blow moulding (shampoo, cosmetic and drinks bottles); injection moulding (cutlery, hair-brushes and combs, stationery); and foam (cups, food trays and cushioning).

Bionolle is the undoubted market leader in Japan, although it should be stressed that the quantities on the market are still very small. Plans for a 30,000-50,000 tonnes/year commercial-scale plant at Oita, for which a time scale was actually unveiled in 1995, have been repeatedly postponed. In recent years, the company has put more emphasis on the improvement of resin quality suitable for high-speed moulding.

The main market application for Bionolle in Japan at present are in agriculture and civil engineering. The main sources of market expansion are expected to come from these applications and as a packaging material for electrical and audio-visual equipment parts.

Mitsui Chemicals, which was formed by the merger of Mitsui Toatsu Chemical and Mitsui Petrochemicals in October 1997, is one of Japan's largest chemicals concerns. Biodegradable polyactic acid is now produced under the brand name Lacea within a dedicated business development unit of the same name. The product is made at a 500 tonnes/year semi-commercial plant at its factory in Omuta, which has been in operation since 1996.

The company has invented a new and unique technology facilitating the manufacture of polylactic acid via a direct condensation polymerization reaction of lactic acid instead of the usual two-step reaction. This patented process is known to rely on special solvents, catalysts and processing techniques, but no more details have been disclosed as yet.

Lacea is based on lactic acid from fermented starch, and so can be derived from variety of renewable resources, such as corn, beet, cane and tapioca. The company says that the manufacturing process yields economical biodegradable plastics, which can be extruded and injection moulded like conventional polyesters.

Lacea is comparable to PET in terms of transparency and similar to polystyrene or PET in terms of processability. It also claims good mould resistance, low heat combustion which is similar to that of paper, superior stability in processing use and biodegradability superior to that of earlier polylactic acid-based material. One grade is said to be stiffer and tougher than polystyrene, with better optical properties.

As with Bionolle, ambitious plans were made and plans for a fully commercial plant were announced in the following years and, as with Bionolle, these are yet to come to fruition. It is estimated that the selling price would be around Yen600/kg for material produced in a factory with a capacity of several thousand tones/year and Yen300/kg for material produced in a factory with a capacity of several tens of thousands tonnes/year.

Marketing in Japan is currently concentrated in three specific fields where the product's transparency, processability and the renewability of the resources are thought to be particularly advantageous. These are: packaging and containers; agricultural, forestry and civil engineering; and composting and waste treatment.

The number of product introduction has been limited because Lacea is still under development. Those already launched include: a cosmetic container, an organic vegetable packaging material and cutting blade made food wrapping film.

Daicel Chemical Industries developed biodegradable blends of two different kinds of material - polycaprolactone and acetyl cellulose resin- by 1996. Its Celgreen brands of both materials are now manufactured at a pilot plant in Ohtake. The polycaprolactone-based material is often used as a modifying agent in other types of biodegradable plastics.

Daicel has made significant steps forward in recent years. In 1998, it attained satisfactory results in field tests of mulching films made from Celgreen and established technology for its mass production. The material proved to have a high degree of biodegradability, with no detrimental effects on plants or equipment used in the field afterwards, and can be blown into film using conventional equipment.

More recently, Daicel and the Japan Atomic Energy Research Institute announced that they had discovered a radically improved production technology for polycaprolatone by the use of gamma radiation to super-cooled pellets to introduce a grafted branching structure to the molecule and thereby improve its melt viscosity, heat resistance and biodegradability in soil or in enzymes. This development opens up applications in foamed and other products, such as expanded sheets, cushioning material, insulation material, loosefill packaging, and in shock-absorbing sheets and nets for agricultural purposes.

The plant at Ohtake is currently said to have a capacity of 1,000 tonnes/year. However, the two recent advances mean that the eventual increase in production may be substantially greater than that.

Shimadzu has developed a fermentation process for lactic acid and has also collaborated with Mitsubishi Plastics Industries to develop poly-L-lactic acid. The company now has a 100 tonnes/year pilot plant, which was built in the mid-1990s in Otsu. The resins are marketed under the trade name Lacty.

Like the other players, Shimadzu made plans to scale up to a higher capacity (1,000 tonnes/year) before the end of decade. These plans have yet to be realized but, in 1997, Shimadzu and Kobe Steel brought onstream a semi-commercial plant with a capacity of several hundred tonnes/year to carry out a continuous polymerization process for Lacty.

Shimadzu has been involved in a number of development ventures, including one with Mitsubishi Plastics industries film. More substantially, Lacty was developed to make fibres for clothing textiles with Kanebo. In 1996, Kanebo began sales of clothes made from the new material, which is called 'Lactron'

Lactron claim the highest melting point of any biodegradable fibre yet developed. It is similar to other synthetic fibres in terms of processability and physical properties, and can be woven into mono-filament, spunbond or staple. After use, it can be decomposed completely into water and CO2 in soil or sea water.

A target of yen 50 million sales was set for the first year and Kanebo sees potential for strong expansion in the coming five years. Textiles have been a major boom area for polylactic acid materials in the past year.

Shimadzu also sees potential applications in industrial and construction materials, where Lacty can be used in place of PET long fibres or polypropylene short fibres in soil surfaces stabilization. The company is also eager to broaden lacty's potential applications by blending it with Celgreen or Bionolle.

The gigantic Mitsubishi Corporation has been active in several areas of biodegradable plastics through different operating arms. This reflects its very diverse interests, which are dominated by industrial chemicals and plastics.

Development work in the field has frequently been in co-operation with various others. For instance, Mitsubishi Plastics industries has worked with both Showa Highpolymer and Shimadzu on biodegradable films. It now has a marketing co-operation with Cargill Dow in Asia, which effectively enables Showa Highpolymer's Bionolle to be used in blends with Cargill Dow's EcoPla. The corporation markets Enviro-plastic for planet polymer and have worked with Mitsui Toatsu and Toppan printing on using polylactic acid-based compostables in prepaid cards.

The division which has developed biodegradables in its own right is Mitsubishi Gas Chemical, whose product is based on blend of polyhydroxy butyrate (PHB) and polycaprolactone and was developed in partnership with JSP and the National Institute of Bioscience & Human Technology.

Later, Mitsubishi Gas Chemical joined the Research Institute for innovative Technologies for the Earth (RITE) in its development work on biodegradable plastics, with the aim of developing technology to allow the production of PHB at a high yield via the continuous fermentation of bacteria living on methanol. The material they developed, known as Biogreen is now commercially available in Japan. Showa Kako has used it to produce natural latex gloves.

Mitsubishi Gas Chemical has also developed a biodegradable polyester carbonate resin, synthesized from polybutylene succinate and aliphatic diol using the ester exchange resin and a new manufacturing method for methyl lactate, which it is considering as a raw material for biodegradable plastics. These two developments could have great potential.

Dainippon Ink & Chemicals is one of Japan's largest chemical concerns and has for some years been developing biodegradable plastics at its central 'Comprehensive Laboratory' in Chiba. These are based mainly on lactic acid and copolymerised with aliphatic polyester and a catalyst.

The company can make both rigid and flexible polylactic acid grades simply by varying the copolymer content from a smaller percentage for rigid grades to a higher one for flexible grades. The flexible grades have 1.5 times the tensile strength, elastic modulus and elongation of polypropylene while the rigid grades have the same tensile strength and elasticity of polystyrene and tensile elongation 20 times greater.

Both grades are also said to be more readily processable than other biodegradables, and can be injection moulded or extruded into film, sheet or foamed agricultural or sanitary products. Dainippon's polymers are expected to be mainly suitable to packaging. Other applications are envisaged in compost bags, cushioning materials, agricultural and fishing materials and sanitary products.

Initial plans were to finish the development work in 1997 and subsequently construct a 2,000-3,000 tonnes/year semi-commercial production facility. Dainppon thinks than the market is not yet sufficiently mature to embark on full-scale commercial production and is now awaiting further market developments.