E series

The Asaprene™ E and Tufdene™ E series for silica-compound rubber products

E Series Essentials

he E Series of styrene/butadiene and butadiene rubbers, in Asaprene™ E and Tufdene™ E versions, facilitate extremely fine, uniform silica dispersion in various rubber types and blends, enabling a major new advance in the production and performance of silica-compound rubber for automotive tires that set new standards in low heat buildup, high resilience, and low compression set, and for a growing range of other industrial and consumer applications.

The silica-dispersal characteristics of the E Series polymers are inherent to their polymer design, and in particular to the functional groups of their molecular chains which effectively promote rubber/silica affinity. Their development and design are the result of decades of expertise and leadership in rubber, polymer, and materials technology at Asahi Kasei.

Salient E Series effects

  • Low compression set
  • Higher abrasion resistance
  • Lower heat buildup
  • Higher resilience
  • Enhanced low-temperature characteristics

Targeted fields of E Series application

  • Tires
    1. – Automotive
    2. – Studless
    3. – Colored tires for bicycles, wheelchairs, other special vehicles
    4. – Solid tires for forklifts, other small vehicles
  • Footwear
  • Vibration damping and control
  • Automotive parts and components
  • Rubber rollers, belts, other industrial product


Structure SBR Low PCA oil(phr) 37.5
Mooney visc.ML1+4, 100°C 69 Sstyrene content(%) 35.5
Applications Tires Bale weight(kg) 35kg

Please note that all data and values are given as typical results obtained with the indicated test methods for purposes of basic reference in grade selection only, and not as any product specification or warranty of any nature, and are subject to change without notice.

Background of E Series development for tire applications

Three fundamental measures of tire performance are rolling resistance, wet-skid resistance, and abrasion resistance, as they are major determinants of fuel efficiency, driving safety, reliability, and service life. Tire-tread composition and design are critical to all three. Among tire manufacturers, a primary focus of the longstanding and continuing efforts for new advances in tire performance is the development of higher-performance tire-tread compound.

In recent years, the growing environmental awareness and demand for resources and energy conservation have sharply increased the requirement for fuel efficiency, and for tires that help to meet this requirement. This has accelerated the efforts for development and adoption of silica particles as a reinforcing filler in tire-tread compounds, in place of the traditional carbon-black filler, because of its recognized potential for a far superior balance of fuel efficiency and wet-road control.

As a hydrophilic material, silica does not readily disperse in the inherently hydrophobic rubber polymers, and process technologies have therefore been developed to coat the silica with silane coupling agents, and thus enable effective dispersion.

With the development and introduction of the Asaprene™ E and Tufdene™ E series, and the interaction between their functional groups and silanol groups on the silica particle surface, it has now been found possible to achieve an extremely fine, uniform silica dispersion in tire-tread rubber compounds, thus facilitating a major new advance in fuel-efficient tire design and production.

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We, Asahi Kasei Group, request that customers who are considering using our products in medical, pharmaceutical, cosmetic and other related applications (hereinafter collectively called “Medical Applications”) shall contact us and confirm our policy on Medical Applications in advance. Information herein regarding conformity to certain laws and regulations are as of January, 2015. Please consult with us for the latest status. We make no guarantees or warranties, express or implied, concerning the suitability of our products for use in Medical Applications. It is not our responsibility to determine if our products are safe, lawful, and technically suitable for intended applications.