Tokyo, Japan, Feb 26 – Toray Industries, Inc., announced that it has developed a proprietary technology to produce bio-based 2-pyrrolidone, a raw material in its polyamide 4, which delivers excellent biodegradability (see note 1) in marine and other environments and helps address microplastic issues. The company will use this technology to verify the scale-up of bio-based polyamide 4, with a view to offering it by the fiscal year ending March 2029, mainly for microparticles in foundation, eyeshadow, and other cosmetics.
In recent years, ocean discharges of microplastics (note 2) from cosmetics and facial cleansers have become a key environmental issue, prompting various countries (note 3) to restrict their use. Toray set about developing and launching polyamide 4 in response to this situation.
The conventional feedstock for 2-pyrrolidone, the raw material in polyamide 4, is petroleum-based. Toray embarked on R&D into synthesis approaches with sugars and other biomass sources, resulting in its bio-based version. The sizes and shapes of polyamide 4 microparticles from polymerizing and processing 2-pyrrolidone with this technique are comparable to those of conventional offerings. This bio-based feedstock conversion does not affect end products.
It is also worth noting that reactions are milder than those of regular petrochemical processes. Toray’s breakthrough should help lower carbon dioxide emissions across the value chain, from raw materials through polyamide 4 microparticle production.
The applications of 2-pyrrolidone made with Toray’s technology extend well beyond polyamide 4. It is also a feedstock for N-methylpyrrolidone, used extensively in manufacturing semiconductor materials and engineering plastics (note 4), and for N- vinylpyrrolidone (note 6), a monomer for high-performance polymers in pharmaceuticals and other applications. This opens the door to bio-based production across diverse materials supporting next-generation industries.
Toray is pushing ahead with initiatives to transition to a circular economy and conserve natural resources as part of its sustainability efforts. The company will accordingly keep pursuing R&D in keeping with its commitment to delivering new value and contributing to social progress.
Results from the Ministry of Environment-funded Projects to Promote the Construction of Decarbonized Circular Economy Systems (FY2023 and FY2024) contributed to Toray’s technological breakthrough.
Notes
1. With biodegradation, bacteria, fungi, and other microorganisms break down organic compounds into simpler inorganic substances, including water and carbon dioxide. Biodegradation is generally slower in the sea, where microorganisms are less abundant than in the soil.
2. Microplastic particles are smaller than 5 mm. They include primary microplastic microbeads in products like facial cleansers and secondary microplastic fragments from the degradation and fragmentation of items like plastic bottles and shopping bags owing to ultraviolet radiation and waves. There are concerns about the adverse effects of microplastics on ecosystems and human health across the food chain.
3. Strengthening of Microplastic Regulations Worldwide
Europe amended its Registration, Evaluation, Authorization and Restriction of Chemicals regulation in 2023 to prohibit the use of cosmetics and other products intentionally incorporating microplastics after a transition of six to 12 years. The regulation exempts plastics meeting specific biodegradability test standards. Toray’s polyamide 4 microparticles meet the OECD 301F ready biodegradability standard and are thus not subject to this regulation.
4. Engineering plastics offer high mechanical strength and heat resistance. Their light weight and high performance make them common substitutes for metals, including in automotive parts.
5. N-methylpyrrolidone is a liquid compound in which a methyl group replaces the hydrogen on the nitrogen atom of 2-pyrrolidone. It has a high boiling point, excellent chemical stability, and strong solvency for diverse compounds, and is a common cleaning agent, paint stripper, and solvent.
6. N-vinylpyrrolidone is a liquid compound in which a vinyl group replaces the hydrogen on the nitrogen atom of 2-pyrrolidone. Polymerization from the vinyl group yields polyvinylpyrrolidone. It serves as a thickener in cosmetics, a binder in pharmaceutical tablets, and a clarifying agent in alcoholic beverages.
