1. Applied to footwear, it enhances wear resistance, cut resistance, and compression resistance, and improves flexibility.

2. Applied to rollers, it increases wear resistance, aging resistance, and load-bearing capacity, improves processability, and reduces water absorption and hysteresis.

3. Applied to mechanical castings, it enhances modulus and thermal aging performance, improves dynamic properties, and reduces swelling in viscous solvents.

4. Applied to hoses, it improves surface wear resistance, enhances modulus, thermal aging performance, and adhesion between reinforcing agents.

5. Applied to tires, it increases wear resistance, reduces hysteresis, enhances modulus, maximizes adhesion performance, improves processability, tread wear resistance, heat cracking resistance, adhesion between carcass and filler, and adhesion of the tire cushion layer.

6. Applied to flat belts, it improves wear resistance, enhances anti-reversion properties, reduces the cost of clay as a substitute for carbon black, improves adhesion of tire cord, and increases flex life and modulus. For V-belts, it enhances modulus, increases wear resistance, extends flex life, and improves adhesion of reinforcing materials.

1. When used alone in rubber products, its functions are: ① as a coupling agent for non-black fillers; ② maintaining vulcanization balance to increase anti-reversion properties; ③ as a vulcanizing agent to achieve good thermal aging performance. The recommended dosage is 3-13% for silica-filled systems and 0.5-1.0% for clay and mica.

2. Adding 0.5-1.0% of Si-69 to clay fillers or 1.0-4.0% to silica pigments can effectively couple non-black pigments with synthetic rubber, increasing modulus and improving wear resistance.

3. Balanced vulcanization: Si-69 contains four sulfur atoms in its molecular structure. At vulcanization temperatures, Si-69 and sulfur participate in the polysulfide crosslinking process. The crosslinking speed of the tetrasulfane group in Si-69 is similar to the reversion rate of sulfur vulcanization, thus providing anti-reversion properties and forming a suitably balanced vulcanizate. This is known as balanced vulcanization. Dynamic flex properties (e.g., heat build-up, crack growth, etc.) are significantly improved.

As a vulcanizing agent, replacing all sulfur in NR, SBR, and NBR blends with Si-69 and a thiuram accelerator results in products with excellent coupling effects and superior thermal aging performance. Si-69 is a silane coupling agent that functions as both a crosslinker and a processing aid in rubber products. The theoretical basis of Si-69's action lies in the coupling of its silane groups with silica and silicate structures in non-black pigments, known as a condensation reaction. The four sulfur atoms in the molecule contribute to vulcanization/accelerator activity, enhancing or modifying the aging characteristics in the vulcanizate.