Achieving High Biomass Content (48%) While Maintaining the Elasticity and Toughness of Polyurethane Elastomers

NOK Corporation (Head Office: Shibadaimon, Minato-ku, Tokyo; Representative Director, Group Chief Executive Officer: Masao Tsuru; hereinafter "NOK") has developed a new biomass-based material for urethane packings (polyurethane elastomer), achieving a biomass content¹ of 48%.

The material replaces a portion of the key polyurethane raw materials with plant-derived polymers, reducing CO2 emissions during raw material production by approximately 48%² compared to conventional materials. Despite this, it fully retains the rubber elasticity and resin toughness that define NOK's flagship polyurethane elastomer products, delivering on both environmental and performance fronts.

Packings made from this material are suited for hydraulic equipment using biodegradable hydraulic fluid (such as eco-friendly hydraulic cylinders), where their superior sealing properties prevent oil leaks and help reduce environmental impact.

Background to Product Development

Growing demand for decarbonization and environmental sustainability has made "sustainable manufacturing" a priority across the materials industry, with increasing pressure to move away from petroleum-based inputs and reduce overall environmental impact.
The new biomass material for polyurethane packings addresses both goals at once: achieving "carbon neutrality" through high biomass content and supporting a "circular economy" through compatibility with biodegradable hydraulic fluid. Developing the material required overcoming significant technical hurdles. Increasing the proportion of plant-derived polymers in polyurethan makes stable molding and curing more difficult and maintaining the performance characteristics of polyurethane elastomers becomes harder to achieve. Biodegradable hydraulic fluid also presents a challenge, as it tends to cause excessive swelling in packings, accelerating wear and compromising durability.
NOK has successfully resolved these challenges, producing a material that is biomass-based yet retains the full characteristics of polyurethane elastomers with proven durability against biodegradable hydraulic fluid. This was made possible by NOK's integrated technology platform, which covers the entire process from material development through to evaluation and analysis.

Key Features of the Newly Developed Biomass Material for Polyurethane Packings

•Environmental and core performance in one: High biomass content without compromising polyurethane's inherent durability and sealing performance.
•Enabling eco-friendly hydraulic systems: Suitable for use as a packing material in construction machinery and other equipment operating in environmentally sensitive areas, such as forests and waterways, where oil leaks pose a direct risk of environmental damage. Combined with biodegradable hydraulic fluid, it supports the development of hydraulic cylinders with a significantly reduced environmental footprint.
•This material has received the "Biomass Mark" certification (Certification No.: 250132) from the Japan Organics Recycling Association (JORA).

1 Biomass content: The proportion of plant-derived raw materials contained in the product.

2 Approx. 48% reduction: Based on in-house research, compared to in-house products. Contributes to reducing CO2 emissions by decreasing the use of petroleum resources.

NOK's Biomass Product Lineup

• Rubber Pole Biomass Type (Certification No.: 220348, Biomass Content: 39%)
  A rubber pole incorporating plant-derived raw materials.
• Biomass Material O-Ring (Certification No.: 240090, Biomass Content: 30%)
  An O-ring made using plant-derived raw materials.