SRI uses bio-liquid rubber in winter tire for better ice-grip

Tokyo – Sumitomo Rubber Industries (SRI) has developed a winter tire using Kuraray-supplied liquid farnesene rubber (LFR) as a performance enhancing additive, the Japanese synthetic rubber supplier announced 20 Feb.

Tokyo-based SRI has used the additive in the production of its latest studless tire Winter Maxx 02, according to Kuraray’s announcement.

Combining the LFR with rubber compounds, claims Kuraray, improves the tire’s ice -grip performance at low temperatures, while impeding the hardening of rubber compounds over time.

Biofene, Amyris’ brand of a long-chain, branched hydrocarbon molecule called farnesene (trans-ß-farnesene), is produced through fermentation of sugarcane.

Kuraray said it has discovered a variety of LFR’s “unique advantages” and that it will continue to optimise its molecular design to develop new applications.

The viscosity of LFR, said Kuraray, is “much lower” compared with current liquid isoprene rubber.

When used as an additive in rubber compounds, LFR shows high plasticity while still maintaining “excellent flexibility even at low temperatures and improves ice grip performance,” the company added.

The Japanese speciality chemicals company and Amyris went into partnership with Amyris in 2011.

“Together [the two companies] created technology that refines Amyris’s biomass material farnesene to a level of purity suitable for polymerisation as well as technology that synthesises LFR,” explained Kuraray.

Through the partnership, the companies “discovered relationships between various properties when combining LFR’s molecular structure with rubber compounds and began supplying LFR to tire manufacturers,” it added.

Kuraray and Amyris signed a multi-year collaboration extension in December 2016, which includes joint marketing of products to industry and end customers.

Explaining the technology further, Kuraray stated: “Due to its optimal molecular weight, LFR reacts completely with solid rubber during vulcanisation, meaning, unlike an oil, which would migrate to the rubber’s surface over time and thus impede hardening, it stays bonded. Therefore, its ice grip performance is maintained over the long term.

“LFR possesses a highly branched brush-like structure with molecular chains that do not easily become entangled with one another. In addition, a highly reactive double bond on the end of each branch ensures that, when vulcanized, LFR completely reacts with solid rubber and solidifies.”