Censil precipitated silica for rubber — high dispersion silica filler for green tires, conveyor belts, rubber soles. Reinforcement & rolling resistance reduction. Alternative to Ultrasil & Zeosil. Free sample.
Censil 180GR is a granular grade precipitated silica for rubber reinforcement. The granular form provides ultra-low dust handling, ideal for automated rubber compounding systems.
| Parameter | Specification |
|---|---|
| Model | Censil 180GR |
| Appearance | Granular |
| Loss on Drying (105C) % | 4.0-8.0 |
| Ignition Loss (1000C) % | <=6.0 |
| DBP Absorption (ml/100g) | 200-280 |
| SiO2 Content % | >=98.5 |
| BET surface area (m2/g) | 180-215 |
| pH (5% suspension) | 6.0-7.0 |
| Heavy Metals (Pb) mg/kg | <=30 |
| Na2SO4 % | <=2.5 |
| 20 Mesh Sieve Residue % | >=65.0 |
| 60 Mesh Sieve Residue % | >=75.0 |
| Application | Reinforcing filler for rubber (low dust granular type) |
Censil is a specialized precipitated silica for rubber manufacturer, produced by Longyan Shenghe Chemical Co., Ltd. in Fujian, China. Censil rubber silica filler is engineered for the demanding requirements of the rubber industry — providing high reinforcement, excellent dispersion, and strong filler-polymer interaction through silane coupling agent compatibility.
As a leading China rubber silica supplier, Censil serves tire manufacturers, industrial rubber goods producers, and rubber compounders across 40+ countries. Censil offers two optimized grades for rubber applications: Censil 165MP (micropearl form, BET 155-175 m²/g) for general-purpose rubber reinforcement, and Censil 180GR (granular form, BET 180-215 m²/g) for high-dispersion requirements in tire manufacturing and high-performance rubber goods. Both grades are fully compatible with standard silane coupling agents used in the rubber industry, making Censil a cost-effective alternative to Ultrasil and Zeosil rubber silica brands.
Censil precipitated silica for rubber is a key ingredient in modern green tire technology. By replacing part or all of the carbon black in tire tread compounds, silica significantly reduces rolling resistance (improving fuel efficiency), enhances wet grip (improving safety), and maintains good abrasion resistance (ensuring tire longevity). This combination of properties — historically considered a "magic triangle" trade-off — is the driving force behind the global shift from carbon black to silica in tire tread formulations.
| Tire Component | Recommended Grade | Typical Loading (phr) | Key Benefits |
|---|---|---|---|
| Passenger Car Tire Tread (PCR) | Censil 180GR | 40-80 phr | Low rolling resistance, wet grip improvement |
| Truck/Bus Tire Tread (TBR) | Censil 180GR | 30-60 phr | Reduced heat buildup, extended tread life |
| Tire Sidewall | Censil 165MP / 180GR | 10-30 phr | Flex crack growth resistance, ozone resistance |
| Tire Inner Liner (Tubeless) | Censil 165MP | 5-15 phr | Air retention improvement with halobutyl rubber |
| Belt Edge Wedge / Filler | Censil 180GR | 20-40 phr | Low hysteresis, reduced shoulder temperature |
| Off-the-Road (OTR) Tire Tread | Censil 180GR | 20-50 phr | Cut/chip resistance, heat dissipation |
For tire manufacturing, Censil 180GR is the preferred grade — its high dispersion granular form ensures uniform silica distribution in the rubber compound during internal mixing, while the BET surface area of 180-215 m²/g provides an optimal balance of reinforcement and processability. Combined with silane coupling agents (Si69/TESPT), Censil rubber silica enables tire compounds that meet the latest EU tire labeling requirements for low rolling resistance (class A/B) while maintaining good wet grip (class A/B).
Beyond tire manufacturing, Censil precipitated silica for rubber is widely used in industrial rubber products where specific mechanical, thermal, or aesthetic properties are required. Silica reinforcement provides advantages over carbon black in applications demanding low heat buildup, high tear strength, color flexibility, or electrical insulation properties.
| Rubber Product | Recommended Grade | Typical Loading (phr) | Key Benefits |
|---|---|---|---|
| Rubber Rollers (Printing, Paper, Steel) | Censil 165MP / 180GR | 20-50 phr | Low heat buildup during high-speed operation, good compression set |
| Conveyor Belts (Mining, Industrial) | Censil 180GR | 20-40 phr | Tear resistance, cut growth resistance, low heat buildup |
| Rubber Hoses (Hydraulic, Automotive) | Censil 165MP | 15-35 phr | Pulse resistance, flex fatigue resistance |
| Vibration Isolators & Engine Mounts | Censil 180GR | 25-50 phr | Low dynamic heat buildup, consistent damping properties |
| Rubber Sheets & Gaskets | Censil 165MP | 15-30 phr | Good compression set, chemical resistance |
| Cable & Wire Insulation | Censil 165MP | 20-40 phr | Electrical insulation, flame retardancy synergy |
| Timing Belts & V-Belts | Censil 180GR | 25-45 phr | Low heat buildup, high tensile, flex crack resistance |
For rubber rollers, Censil precipitated silica ensures low heat buildup during high-speed operation — a critical factor for printing and paper machine rollers where thermal degradation causes premature failure. In conveyor belts for mining and bulk material handling, Censil rubber silica provides the tear and cut resistance needed to withstand abrasive loads while maintaining belt flexibility.
Censil precipitated silica for rubber is a preferred reinforcing filler for rubber soles and footwear outsoles. Unlike carbon black, silica enables the production of translucent and colored rubber soles while maintaining excellent abrasion resistance, tear strength, and flex fatigue properties. The footwear industry relies heavily on silica for aesthetic flexibility and performance.
| Footwear Type | Recommended Grade | Typical Loading (phr) | Key Benefits |
|---|---|---|---|
| Sports shoe outsoles | Censil 180GR | 30-60 phr | Abrasion resistance, flex crack resistance, grip |
| Casual Shoe Soles (Translucent) | Censil 165MP | 40-70 phr | Transparency, color matching, good wear |
| Safety Shoe Outsoles | Censil 180GR | 35-55 phr | Oil resistance, heat resistance, slip resistance |
| Rubber Sandals & Flip-Flops | Censil 165MP | 25-45 phr | Color versatility, UV stability, comfort |
| Industrial Boot Soles | Censil 180GR | 30-50 phr | Chemical resistance, abrasion, anti-static options |
For rubber soles, Censil 165MP is the most popular grade for translucent and light-colored footwear applications. The micropearl form ensures uniform dispersion and smooth surface finish. For demanding applications like sports shoe outsoles and safety footwear, Censil 180GR provides the high reinforcement and abrasion resistance needed to meet footwear industry standards (SATRA, ISO 20871).
Censil offers 2 grades of precipitated silica specifically optimized for rubber applications, covering both micropearl form (for easy dispersion and smooth surface finish) and granular form (for high-dispersion requirements and low-dust handling in internal mixers).
| Property | Censil 165MP (Micropearl) | Censil 180GR (Granular) |
|---|---|---|
| Appearance | Micro-pearl | Granular |
| SiO₂ Content | ≥98% | ≥98.5% |
| BET Surface Area (m²/g) | 155-175 | 180-215 |
| DBP Absorption (cm³/g) | 2.00-2.80 | 2.00-2.80 |
| Loss on Drying (105°C) % | 4.0-8.0 | 4.0-8.0 |
| Loss on Ignition (1000°C) % | ≤7.0 | ≤6.0 |
| pH (5% suspension) | 5.0-8.0 | 6.0-7.0 |
| Heavy Metals (Pb) mg/kg | ≤30 | ≤30 |
| Na₂SO₄ Content % | ≤1.5 | ≤2.5 |
| Sieve Residue | ≥80% retained on 100 mesh | ≥65% (20 mesh), ≥75% (60 mesh) |
| Form Advantage | Easy dispersion, smooth surface finish, translucent soles | Low dust, high dispersion, efficient internal mixing |
| Primary Applications | Rubber soles, translucent products, hoses, gaskets, cable insulation | Tire treads, conveyor belts, rollers, vibration mounts, belts |
Rubber manufacturers evaluating rubber silica filler suppliers often compare Censil against leading international brands. Below is a specification-level comparison showing how Censil matches international rubber silica grades while offering significant cost advantages as a China rubber silica supplier.
| Property | Censil 165MP | Censil 180GR | Ultrasil® 7000GR | Zeosil® 1165MP |
|---|---|---|---|---|
| SiO₂ Content | ≥98% | ≥98.5% | ≥98.5% | ≥98% |
| BET Surface Area | 155-175 m²/g | 180-215 m²/g | 175-200 m²/g | 155-175 m²/g |
| DBP Absorption | 200-280 ml/100g | 200-280 ml/100g | 200-260 ml/100g | 200-260 ml/100g |
| Form | Micropearl | Granular | Granular | Micropearl |
| Loss on Drying (105°C) | 4.0-8.0% | 4.0-8.0% | 4.0-7.0% | 4.0-7.0% |
| pH (5% suspension) | 5.0-8.0 | 6.0-7.0 | 6.0-7.5 | 5.5-7.5 |
| High Dispersion Grade | — | ✅ Yes | ✅ Yes | ❌ Standard |
| Silane Compatible | ✅ Yes | ✅ Yes | ✅ Yes | ✅ Yes |
| Cost Index | 100 | 100 | 150-170 | 140-160 |
| Lead Time | 2-3 weeks | 2-3 weeks | 6-10 weeks | 4-8 weeks |
| Censil Grade | Ultrasil® Equivalent | Zeosil® Equivalent | Tokusil® Equivalent |
|---|---|---|---|
| Censil 165MP (micropearl, BET 155-175) | Ultrasil® 7000 series | Zeosil® 1165MP | Tokusil® 200 |
| Censil 180GR (granular, BET 180-215) | Ultrasil® 7000GR / Hi-Sil® TZ-150G | Zeosil® 1195MP | Tokusil® 300 |
Key Finding: Censil rubber silica matches international brands in all critical rubber compounding parameters — BET surface area, DBP absorption, silane coupling agent compatibility, and dispersion characteristics — while offering 25-40% cost savings and significantly shorter lead times. For rubber manufacturers seeking a Ultrasil alternative or a Zeosil alternative for rubber applications, Censil provides drop-in replacement capability.
The effectiveness of precipitated silica as a rubber reinforcement filler depends critically on the use of silane coupling agents. Without silane coupling agents, the highly polar silica surface (covered with silanol Si-OH groups) cannot form strong chemical bonds with non-polar rubber polymers. Censil rubber silica is fully compatible with all standard silane coupling agents used in the rubber industry.
| Component | Function | Mechanism |
|---|---|---|
| Silanol End (Si-OR) | Bonds to silica surface | Condensation reaction between silanol groups on silica and hydrolyzed silane during mixing. Creates Si-O-Si covalent bonds with the filler surface. |
| Sulfur End (Sx) | Bonds to rubber polymer | Participates in sulfur vulcanization cure reaction, forming covalent crosslinks between the silane and rubber polymer chains. |
| Bridge Structure | Creates chemical bridge | The propyl chain (-(CH₂)₃-) provides flexible spacing, allowing the sulfur end to reach and react with rubber polymer chains during vulcanization. |
| Silane Coupling Agent | Chemical Name | Common Brand | Typical Dosage (phr silica) | Best For |
|---|---|---|---|---|
| Si69 (TESPT) | Bis-(3-triethoxysilylpropyl) tetrasulfide | X-50-S (Evonik) | 8-12% of silica loading | Tire treads, general rubber — most widely used |
| TESPD | Bis-(3-triethoxysilylpropyl) disulfide | X-50-Si (Evonik) | 8-12% of silica loading | Tire treads — faster cure, lower scorch |
| A-174 (VTES) | Vinyltriethoxysilane | Silquest A-174 | 2-5% of silica loading | Peroxide-cured systems, silicone rubber |
| Si75 (TESPTS) | Bis-(3-triethoxysilylpropyl) tetrasulfide (supported) | X-50-Si FD (granular) | 10-15% of silica loading | Easier handling, reduced odor |
Best Practice: For optimal performance of Censil rubber silica in tire and industrial rubber applications, we recommend Si69 (TESPT) at 8-12% of the silica loading. The silane coupling reaction occurs during the first mixing stage (non-productive mix) at temperatures of 145-160°C. Proper mixing protocol — including adequate mixing time and temperature — is essential for complete silane-silica reaction and optimal rubber compound performance.
Understanding how silica reinforces rubber is essential for optimizing compound formulations. The reinforcement mechanism of precipitated silica in rubber involves multiple interacting phenomena at the micro and nano scale.
| Mechanism | Description | Impact on Rubber Properties |
|---|---|---|
| Hydrodynamic Reinforcement | Rigid silica particles restrict the mobility of surrounding rubber polymer chains. The effective filler volume is larger than the actual silica volume due to the immobilized rubber layer (bound rubber) around each particle. | Increased modulus, hardness, and tensile strength. Higher BET surface area → more bound rubber → stronger reinforcement. |
| Filler-Polymer Chemical Bonding (via Silane) | Silane coupling agents create covalent bonds between silica surface and rubber polymer, enabling efficient stress transfer from the soft polymer matrix to the rigid filler particles. | Dramatically improved tensile strength, tear resistance, and fatigue life compared to silica without silane. Reduced hysteresis and heat buildup. |
| Filler-Filler Network (Silica-Silica Interaction) | Silanol groups on silica surfaces form hydrogen bonds with adjacent silica particles, creating a filler network throughout the rubber matrix. This network breaks down under strain (Payne effect) and rebuilds at rest. | Contributes to viscosity, modulus at low strain, and hysteresis. Good dispersion (using high dispersion grades like Censil 180GR) minimizes filler-filler interaction, reducing hysteresis and rolling resistance. |
| Surface Area Effect | Higher BET surface area provides more Contact area between silica and rubber, increasing the volume of bound rubber and the density of silane coupling sites. | Higher surface area → stronger reinforcement but also higher compound viscosity and harder dispersion. Censil 180GR (BET 180-215) provides optimal balance for tire applications. |
| Property | Precipitated Silica (Censil) | Carbon Black (N330/N550) |
|---|---|---|
| Filler Type | White / inorganic (SiO₂) | Black / carbon |
| Filler-Polymer Bonding | Requires silane coupling agent | Direct physical/chemical bonding |
| Hysteresis / Heat Buildup | Low (with silane) — ideal for green tires | Higher — causes heat buildup in dynamic applications |
| Rolling Resistance | Low — reduces fuel consumption | High — increases fuel consumption |
| Wet Grip | Excellent — improves safety | Good |
| Abrasion Resistance | Good (slightly lower than carbon black) | Excellent |
| Dispersion | More difficult — requires higher mixing energy | Easier — readily disperses in rubber |
| Color | White — enables colored/translucent products | Black — only black products |
| Cost per kg | Higher | Lower |
| Best Application | Green tire treads, translucent soles, low-heat rubber goods | Tire carcass, black rubber goods, high-abrasion applications |
The trend in the rubber industry is toward increasing silica usage driven by fuel efficiency regulations (EU tire labeling, CAFE standards) and consumer demand for greener tires. Modern passenger car tire treads can contain 60-80 phr of silica (partially or fully replacing carbon black), while future tire designs may push silica loading even higher. Censil rubber silica is positioned to support this industry transition.
| Property | Specification | Test Method |
|---|---|---|
| SiO₂ Content (dry basis) | ≥98-98.5% (grade dependent) | GB/T 3467 / ISO 3262 |
| Loss on Drying (105°C, 2h) | 4.0-8.0% | GB/T 3467 |
| Loss on Ignition (1000°C, 2h) | ≤6.0-7.0% (grade dependent) | GB/T 3467 |
| BET Surface Area | 155-215 m²/g (grade dependent) | GB/T 3467 / N₂ adsorption |
| DBP Absorption | 200-280 ml/100g | GB/T 3467 |
| pH Value (5% suspension) | 5.0-8.0 | GB/T 3467 |
| Heavy Metals (Pb) | ≤30 mg/kg | GB/T 3467 |
| Na₂SO₄ Content | ≤1.5-2.5% (grade dependent) | GB/T 3467 |
Precipitated silica for rubber is a high-performance reinforcing filler that improves tensile strength, tear resistance, abrasion resistance, and dynamic mechanical properties of rubber compounds. In tire manufacturing, silica reduces rolling resistance and improves wet grip — the key benefits of green tire technology. In industrial rubber products, silica for rubber provides low heat buildup, flex crack resistance, and color flexibility. Common applications include tire treads, rubber rollers, conveyor belts, rubber soles, hoses, vibration isolators, and timing belts.
Both are reinforcing fillers, but they differ fundamentally. Carbon black provides excellent tensile and abrasion resistance but increases hysteresis (heat buildup) and rolling resistance — a disadvantage for fuel-efficient tires. Precipitated silica for rubber, when combined with silane coupling agents, provides comparable reinforcement while significantly reducing rolling resistance and improving wet grip. This is why silica has become the dominant filler in modern green tire tread compounds. Carbon black remains preferred for cost-sensitive applications and where black color is acceptable. Silica additionally enables translucent and colored rubber products (e.g., rubber soles), which carbon black cannot achieve.
Yes. Censil precipitated silica for rubber is a cost-effective alternative to Ultrasil rubber silica (Evonik) and Zeosil rubber silica (Solvay). Censil 165MP matches Ultrasil 7000 series and Zeosil 1165MP specifications, while Censil 180GR is comparable to Ultrasil 7000GR for high-dispersion tire applications. Both Censil grades are fully compatible with standard silane coupling agents (Si69/TESPT, TESPD, A-174). Many rubber compounders have already switched to Censil, achieving 25-40% cost savings without reformulation.
Precipitated silica has a highly polar surface covered with silanol (Si-OH) groups, making it incompatible with non-polar rubber polymers. Without a silane coupling agent, silica would not bond effectively to the rubber matrix, resulting in poor reinforcement, high compound viscosity, and excessive filler-filler interaction (Payne effect). Silane coupling agents like Si69 (TESPT) have dual-function molecules: one end (silanol) bonds to the silica surface, while the other end (polysulfidic sulfur) participates in vulcanization, creating covalent bridges between silica and rubber. This chemical bonding is what enables silica to function as an effective reinforcing filler in rubber compounds.
High dispersion rubber silica refers to precipitated silica grades engineered with optimized particle morphology, surface chemistry, and aggregate structure for rapid, uniform dispersion during rubber mixing. Good dispersion is critical because undispersed silica agglomerates act as stress concentrators, reducing mechanical properties and causing surface defects. Censil 180GR is a high dispersion granular silica (BET 180-215 m²/g) specifically designed for efficient incorporation in tire tread compounds and industrial rubber. The granular form also reduces dust during handling, improving workplace safety and ensuring consistent feed into internal mixers.
Yes. Censil is a China-based rubber silica manufacturer (Longyan Shenghe Chemical Co., Ltd., Fujian Province), supplying precipitated silica for rubber directly from our production facility. As a direct supplier, Censil offers factory pricing with 25-40% cost savings versus imported brands. We supply both micropearl form (Censil 165MP) and granular form (Censil 180GR), with MOQ of 1 ton and 2-3 week lead time. SENSIL International LLC (California, USA) handles international distribution and technical support.