A-189; Z-6062; KBM-803; MTMO; GF70
Momentive; Dow corning; ShinEtsu; Evonik; Wacker
2931900090
Siwin-S31
4420-74-0
| Quantity: | |
|---|---|
3-Mercaptopropyltrimethoxysilane, also referred to as γ-mercaptopropyltrimethoxysilane, is a mercapto-functional silane coupling agent with internal product code Siwin-S31. It is assigned CAS number 4420-74-0 and EINECS number 224-588-5, and is widely used in sealant formulation and rubber modification for industrial applications. The product features a trimethoxysilyl group and a terminal mercapto group, enabling dual reactivity with inorganic substrates and organic polymer systems.
This mercapto silane is produced to match the performance of multiple international commercial grades. The equivalent product designations from major global manufacturers are listed in the table below, retained in its original format:
MomentiveDowcorningShinEtsuEvonikWacker
A-189Z-6062KBM-803MTMON.A
The product is manufactured for commercial procurement and industrial formulation use, supporting consistent performance for batch production in sealant, tire, and rubber goods industries.
The molecular formula of 3-mercaptopropyltrimethoxysilane is C₆H₁₆O₃SSi. Its trimethoxysilyl groups hydrolyze in the presence of moisture to form silanol groups, which form covalent bonds with hydroxyl groups on the surface of glass, metal, and mineral fillers. The terminal mercapto group reacts with polymer chains in rubber and sealant systems, creating a chemical bridge between inorganic materials and organic polymers.
This dual reactivity improves interfacial adhesion and enhances the mechanical properties, water resistance, and durability of composite systems. The mercapto functional group also participates in sulfur vulcanization processes, supporting crosslinking in rubber formulations.
Momentive | Dowcorning | ShinEtsu | Evonik | Wacker |
|---|---|---|---|---|
A-189 | Z-6062 | KBM-803 | MTMO | N.A |
Parameter | Specification |
|---|---|
Product Number | Siwin-S31 |
Chemical Name | 3-Mercaptopropyltrimethoxysilane |
CAS Number | 4420-74-0 |
EINECS Number | 224-588-5 |
Molecular Formula | C₆H₁₆O₃SSi |
Appearance | Colorless Transparent Liquid |
Density | 1.0570±0.0050 g/cm³ |
Refractive Index | 1.4400±0.0050 |
Purity (by GC) | 98% |
HS Code | 2931900090 |
Siwin-S31 is primarily used to improve the adhesion of polysulfide and polyurethane sealants to glass and metal surfaces. When added to sealant formulations, it enhances the bond between the sealant polymer and inorganic substrates, reducing the risk of adhesion failure under temperature cycling, moisture exposure, and mechanical stress. This application serves the construction sealant, insulating glass, and automotive sealant manufacturing sectors, where long-term bonding reliability is required.
The product can be added directly to sealant formulations during the mixing process, with typical addition levels ranging from 0.5% to 2.0% by total formulation weight, depending on substrate type and performance requirements.
In silica-reinforced tire tread compounds, 3-mercaptopropyltrimethoxysilane improves the dispersion of silica filler in rubber matrices and strengthens the interfacial bonding between silica and rubber polymers. This modification contributes to improved low-rolling resistance in tire treads, supporting fuel efficiency performance in tire designs. It also enhances abrasion resistance and wet grip properties of vulcanized rubber compounds.
The product is suitable for use in solution styrene butadiene rubber and other common tire tread polymer systems, and can be added during the internal mixing process of rubber compounding.
The mercapto silane enhances material properties in mineral-reinforced articles such as shoe soles, industrial rubber goods, and molded polymer parts. It improves the compatibility between mineral fillers and polymer matrices, leading to more uniform filler dispersion and enhanced mechanical strength, tear resistance, and aging resistance of finished products.
It is suitable for use in a range of polymer systems including butyl, epoxy, neoprene, nitrile, phenolic, polysulfide, polyurethane, and styrene butadiene. Formulators may adjust addition rates based on specific filler loading and target performance metrics.
Siwin-S31 is available in standard industrial packaging options to meet different commercial procurement volumes:
210 L iron drum: 200 kg net weight per drum, suitable for regular production batches
1000 L IBC container: 1000 kg net weight per container, designed for bulk orders and large-scale manufacturing
All packaging is sealed to prevent moisture ingress and maintain product integrity during transportation and storage. Custom packaging arrangements can be coordinated upon request.
The product should be stored in a cool, dry, and well-ventilated area, with containers kept tightly sealed when not in use. Exposure to atmospheric moisture will cause gradual hydrolysis of the methoxy groups, which may affect product reactivity. Storage temperature should be maintained between 0℃ and 35℃, with direct sunlight and proximity to heat sources avoided.
Under proper storage conditions in original sealed containers, the product has a shelf life of 12 months from the date of manufacture. Material safety data sheets are provided upon request for detailed handling, personal protection, and spill response instructions.
Siwin-S31 is compatible with multiple polymer systems including butyl, epoxy, neoprene, nitrile, phenolic, polysulfide, polyurethane, and styrene butadiene. It is most widely used in polysulfide and polyurethane sealant formulations, as well as sulfur-cured rubber compounds.
Typical addition levels range from 0.5% to 2.0% by total formulation weight. The exact dosage depends on substrate type, filler content, and target adhesion performance. Formulators may conduct small-scale trials to determine the optimal addition rate for specific applications.
The standard 210 L iron drum packaging contains 200 kg of product net weight. For bulk orders, 1000 L IBC containers with 1000 kg net weight are available to reduce logistics and handling costs for large-volume commercial users.
The product requires sealed storage in a cool, dry environment to prevent moisture-induced hydrolysis. It does not require refrigerated storage, but exposure to temperatures above 35℃ and direct sunlight should be avoided to maintain consistent reactivity over the shelf life.
