Crosile-69: High-Efficiency Silane Coupling Agent 

Chemical Name: Bis[3-(Triethoxysilyl)Propyl]Tetrasulfide       Molecular Formula: C18H42O6S4Si2

Molecular Weight: 538.94        CAS Number: 40372-72-3

Product Aliases:

•Silquest® A-1289 (Momentive, USA)       

 •Z-6940 (Dow Corning, USA)

•Si-69 (Evonik, Germany)   

•KBE-846 (Shin-Etsu, Japan)         

•B2494 (UCT, USA)

Introduction to Crosile-69

Crosile-69 (Bis[3-(Triethoxysilyl)Propyl]Tetrasulfide) is a highly effective silane coupling agent widely used in the rubber industry, tire manufacturing, and composite material modification. Its unique molecular structure significantly enhances the properties of rubber and other materials, improving mechanical performance, filler dispersion, wear resistance, aging resistance, and environmental sustainability.

Key Properties of Crosile-69

• Appearance: Low viscosity, light yellow to transparent liquid with a slight odor

• Density (ρ20): 1.069 g/cm³

• Sulfur Content: ≥22%

• Refractive Index (nD25): 1.493

• Solubility: Easily soluble in many organic solvents (e.g., ethanol, acetone, toluene), but very low solubility in water

Functional Groups of Crosile-69

1.Tetrasulfide Bridge (-S4-): The sulfur bridge allows Crosile-69 to undergo crosslinking reactions during rubber vulcanization, improving rubber strength, hardness, and elasticity.

2.Triethoxy Silane Group (-Si-OCH2CH3): Hydrolyzed to form silanol (-Si-OH), which can react with hydroxyl or carboxyl groups in the rubber matrix, strengthening the bond between the rubber and inorganic fillers.

Mechanism of Action of Crosile-69

Crosile-69 improves rubber properties through three main reaction mechanisms:

1.Hydrolysis and Condensation Reaction: In the presence of water or moisture, the ethoxy groups in Crosile-69 hydrolyze into silanols (-Si-OH). These silanols react with hydroxyl (-OH) or carboxyl (-COOH) groups on the surface of inorganic fillers, forming siloxane bonds (Si-O-C), enhancing the mechanical properties of rubber.

2.Coupling Reaction with Rubber Matrix: The silane groups in Crosile-69 react with functional groups (e.g., hydroxyl or carboxyl) in the rubber matrix, forming siloxane bonds, which improve the bonding between the rubber and fillers, enhancing properties such as tear resistance and aging resistance.

3.Reaction During Vulcanization: The tetrasulfide bridge (-S4-) in Crosile-69 breaks during vulcanization, generating active sulfur intermediates (such as -SH), which can crosslink with double bonds (C=C) in the rubber matrix, forming a stable vulcanization network and further enhancing rubber performance.

Advantages and Characteristics of Crosile-69

• Improved Filler Dispersion: Crosile-69 significantly improves the dispersion of inorganic fillers (e.g., silica, carbon black) in the rubber matrix, reducing filler agglomeration and enhancing the uniformity and physical properties of rubber products.

• Enhanced Mechanical Properties: Crosile-69 enhances the tensile strength, tear resistance, shear resistance, and durability of rubber, making it ideal for high-performance rubber applications.

• Improved Wet Traction and Reduced Rolling Resistance: Crosile-69 is widely used in tire manufacturing to improve wet traction and reduce rolling resistance, helping to meet the performance requirements of green tires.

• Improved Aging and Wear Resistance: Crosile-69 improves the aging resistance and wear resistance of rubber, making it suitable for high-performance industrial rubber products such as seals, hoses, and gaskets.

• Improved Processing Performance: Crosile-69 effectively reduces the viscosity of rubber, enhancing processing fluidity, improving moldability, and reducing the difficulty of demolding.

Applications of Crosile-69

1. Tire Industry: Crosile-69 enhances the mechanical properties of tires, such as wet traction, rolling resistance, and wear resistance, particularly in the production of green tires, helping to reduce energy consumption and carbon emissions.

2. Industrial Rubber Products: In rubber seals, hoses, tapes, and other industrial rubber products, Crosile-69 improves wear resistance, tear resistance, and aging resistance, ensuring reliable performance in harsh environments.

3. Composite Materials: Crosile-69 can be used for modifying fillers in composite materials, improving the compatibility between fillers and the rubber matrix, enhancing material uniformity, processability, and mechanical properties.

4. Green Tire Technology: Crosile-69 is a key component in green tires, improving performance by reducing rolling resistance, enhancing fuel efficiency, and meeting environmental standards.

5. Polymer Modification: Crosile-69 can also be used for polymer modification, enhancing compatibility with fillers, improving overall material properties, and expanding its application in other fields.

Why Choose Crosile-69?

Crosile-69 is a high-efficiency silane coupling agent that significantly improves the performance of rubber and composite materials through its unique hydrolysis, crosslinking, and catalytic action. It is widely used in the tire industry, industrial rubber products, and composite material modification, offering broad application prospects. Crosile-69 not only enhances rubber mechanical and processing properties but also plays a crucial role in improving durability and environmental performance.

By using Crosile-69, you can improve product quality, reduce production costs, and achieve higher production efficiency.