Soluble in water. Sparingly soluble in isopropanol
Acts as a coupling agent of the polymer and filler, improves the dispersibility of the filler.Especially great effect by combination of NR and CB.
It is hardly affected by crosslinking agent and vulcanization accelerator.
・ Natural Rubber / Carbon Black coupling agent
・ Sulfur atom-containing compound
・ Low RR / anti-vibration / high rigidity
In 2015, a historical United Nations Summit established Sustainable Development Goals (SDGs) for the international community. Among the SDGs, chemistry can have the utmost impact on climate change countermeasures. In order to contribute to this goal, Sumitomo Chemical created SUMILINK®, an unprecedented technological leap towards the development of more fuel-efficient tires.
Ⅱ. What are coupling agents ?
Ⅱ-1. Coupling of fillers with rubberHeat generation occurs when rubber is subjected to repeated deformation. During this deformation, fillers in rubber are repeatedly agglomerated and dispersed. If fillers are fixed to polymer chains by a coupling agent, heat generation in rubber will be suppressed by preventing further agglomeration and dispersion.
Ⅱ-2. Improvement of filler dispersionSUMILINK® can prevent filler from agglomeration by interacting with fillers and rubber. As a result, the dispersion of filler in rubber is improved. 3D-TEM images are shown when SUMILINK® was used in CB-NR system. Compared to the image titled “Control” , each CB agglomeration in the image titled “SUMILINK® 200” is relatively small. This means CB is well dispersed. In addition, increase in volume resistivity and decrease in Payne effect were observed. Those results suggest that SUMILINK® improves the dispersion of filler.
Ⅲ. Plausible action mechanism
Ⅲ-1. Concept of SUMILINK®SUMILINK® is a novel compound having two different functional groups.
The performance of SUMILINK® is adjustable by changing the functional groups. Sumitomo Chemical designed the chemical structure of SUMILINK® to perform even when its loading amount is 0.5 – 3.0 phr.
Ⅲ-2. SUMILINK® 100Our hypothesis of the action mechanism for SUMILINK® 100 consists of two steps:
1) Amino group reacts/interacts with the filler in the Mixing step*.
2) Thiyl radical derived from thiosulfonic acid group reacts/interacts with rubber in the vulcanization step.
Since the reaction of thiyl radical occurs in the vulcanization step, the performance of SUMILINK® 100 can be adjusted by changing the conditions of vulcanization such as type of accelerators, ratio of sulfur to accelerator, etc.
Ⅲ-3. SUMILINK® 200SUMILINK® 200 interacts/reacts with filler and rubber in the Mixing step*. Our experimental result suggests the following reaction mechanism: Amino group reacts/interacts with the filler, then the rubber radical formed by an applied shearing force attacks electron deficient olefin.
Ⅳ-1. Fuel economySUMILINK® can improve fuel economy by reducing hysteresis loss without deteriorating the wet grip and anti-abrasion performance, when used in tire applications.
It is well known that wet grip and anti-abrasion performances are in a trade-off relationship. However, SUMILINK® can provide a solution to this problem.
Ⅳ-2. Anti-Vibration RubberSUMILINK® can decrease dynamic magnification of anti-vibration rubber. SUMILINK® 100 shows great performance especially when using conventional vulcanization conditions. However, SUMILINK® 200 does not depend on the vulcanization system.