The Role of Silane in Tire Manufacturing

Silane is a chemical compound that can act as a coupling agent between rubber and silica in tire manufacturing. Silane can improve the dispersion of silica in the rubber matrix, enhance the crosslinking density and bond strength, and reduce the hysteresis loss of the rubber compound. These effects can lead to improved tire performance, such as lower rolling resistance, better wet traction, and longer wear life.

What is Silane?

Silane is a generic term for any compound that contains silicon and hydrogen atoms. There are many types of silanes with different functional groups, such as alkyl, alkoxy, amino, mercapto, and thiocarboxylate. Depending on the functional groups, silanes can have different reactivity and compatibility with rubber and silica.

How Does Silane Work in Tire Manufacturing?

Silane works as a coupling agent that bridges the gap between rubber and silica. Rubber is an organic polymer that has a low affinity for silica, which is an inorganic filler. Silica can improve the stiffness and strength of rubber, but it also increases the viscosity and reduces the processability of the rubber compound. Silane can solve this problem by reacting with both rubber and silica and forming a covalent bond between them.

Silane can also modify the surface properties of silica and reduce its tendency to agglomerate. Silica particles tend to form large clusters due to their high surface energy and polarity. This can reduce the dispersion quality and increase the mixing energy of the rubber compound. Silane can coat the surface of silica particles and lower their surface energy and polarity. This can enhance the dispersion of silica in the rubber matrix and reduce the mixing time and temperature.

Silane can also affect the vulcanization and crosslinking of rubber. Rubber is cured by adding sulfur and other additives that form crosslinks between the polymer chains. Crosslinks can improve the elasticity and durability of rubber, but they also increase the hysteresis loss and heat generation of rubber. Silane can participate in the vulcanization reaction and form additional crosslinks between rubber and silica. These crosslinks can increase the crosslinking density and bond strength of the rubber compound, which can improve its dynamic properties and reduce its hysteresis loss.

What are the Benefits of Silane in Tire Performance?

Silane can improve tire performance in several aspects, such as:

• Lower rolling resistance: Rolling resistance is the force that opposes the motion of a tire on a road surface. It is influenced by the deformation and recovery of the tire tread under load. Silane can reduce the rolling resistance of tires by improving the dispersion of silica in rubber, increasing the crosslinking density and bond strength, and reducing the hysteresis loss of rubber. Lower rolling resistance can lead to higher fuel efficiency and lower carbon dioxide emissions for vehicles.
• Better wet traction: Wet traction is the ability of a tire to grip a wet road surface. It is influenced by the friction coefficient and contact area between the tire tread and the road. Silane can improve the wet traction of tires by enhancing the stiffness and strength of rubber, increasing the crosslinking density and bond strength, and reducing the hysteresis loss of rubber. Better wet traction can lead to shorter braking distance and better handling for vehicles on wet roads.
• Longer wear life: Wear life is the durability of a tire under various driving conditions. It is influenced by the abrasion resistance and fatigue resistance of rubber. Silane can improve the wear life of tires by enhancing the stiffness and strength of rubber, increasing the crosslinking density and bond strength, and reducing the hysteresis loss of rubber. Longer wear life can lead to lower maintenance costs and longer service life for tires.

What are Some Examples of Silane Products for Tires?

There are many silane products available for tire manufacturing, each with different characteristics and advantages. Some examples are:

• NXT silanes: NXT silanes are thiocarboxylate functional silanes that offer superior performance benefits for tires. NXT silanes can deliver lower rolling resistance while maintaining wet traction compared to standard sulfur silanes. NXT silanes can also offer processing benefits for tire manufacturers, such as better dispersion quality, lower compound viscosity, higher extrusion throughput, smoother tread profile, longer shelf life, and less waste.
• NXT Z45 silane: NXT Z45 silane is an advanced silane that is virtually ethanol-free. This silane can dramatically improve
  the dynamic and physical properties of tires, such as rolling resistance, grip, and wear resistance. NXT Z45 silane can also reduce ethanol emissions during tire manufacturing, which can benefit the environment and the health of workers.
• Carbo NXT silane: Carbo NXT silane is a powder form of NXT silane that offers processing flexibility for tire manufacturers. This silane can provide the same performance benefits as NXT silane, but with a longer shelf life and easier handling. Carbo NXT silane can also be used in combination with other silanes to optimize the properties of rubber compounds.

Conclusion

Silane is a versatile and valuable additive for tire manufacturing. Silane can improve the compatibility and interaction between rubber and silica, which can lead to improved tire performance, such as lower rolling resistance, better wet traction, and longer wear life. Silane can also offer processing benefits for tire manufacturers, such as better dispersion quality, lower compound viscosity, higher extrusion throughput, smoother tread profile, longer shelf life, and less waste. There are many silane products available for tire manufacturing, each with different characteristics and advantages. Momentive and Pengrun Ltd. is a leading provider of advanced silanes for tires, such as NXT silanes, NXT Z45 silane, and Carbo NXT silane.