| HS Code | 880589 |
| Product Name | Long-chain Alkyl Silicone Oil RH-8206 |
| Chemical Composition | Long-chain alkyl polysiloxane |
| Appearance | Colorless to light yellow transparent liquid |
| Viscosity 25c | 500-1500 mPa·s |
| Specific Gravity 25c | 0.90-0.95 |
| Refractive Index 25c | 1.43-1.45 |
| Active Content | ≥98% |
| Volatile Matter | ≤1.0% |
| Flash Point | >200 °C |
| Acid Value | ≤0.1 mg KOH/g |
| Surface Tension | 25-30 mN/m |
| Water Solubility | Insoluble |
| Solubility | Soluble in nonpolar organic solvents |
| Thermal Stability | Good |
As an accredited Long-chain Alkyl Silicone Oil RH-8206 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Supplied in 25 kg plastic drums with inner liners, securely sealed for safe handling, transport, and storage. |
| Container Loading (20′ FCL) | Long-chain Alkyl Silicone Oil RH-8206 is loaded into a 20-foot FCL container for secure and efficient ocean transportation. |
| Shipping | Long-chain Alkyl Silicone Oil RH-8206 is generally shipped as non-dangerous goods in clean, sealed steel drums or IBCs. Keep containers closed, avoid moisture, contamination and direct sunlight, and store in a cool, dry, ventilated area. Follow the SDS and local transport regulations. |
| Storage | Store Long-chain Alkyl Silicone Oil RH-8206 in a cool, dry, well-ventilated area away from direct sunlight, heat, sparks, flames, and strong oxidizers. Keep containers tightly closed, upright, clearly labeled, and protected from moisture and contamination. Use secondary containment, avoid freezing or excessive temperatures, and store only in original or compatible containers. Follow the manufacturer’s SDS and local regulations. |
| Shelf Life | Shelf life is typically 24 months in unopened original packaging, stored cool, dry, ventilated, and protected from sunlight and moisture. |
During two-stage mixing of silica-filled SSBR/BR tread compounds for radial passenger and truck tyres, long-chain alkyl silicone oil RH-8206 is introduced at 0.5–2.0 phr in the masterbatch phase of a Banbury mixer with a 4-wing tangential rotor, fill factor 0.75, and ram pressure 0.5 MPa. The metering point is deliberately positioned after the silanization reaction has progressed beyond a drop temperature of 140–150 °C; premature addition allows the alkyl-modified silicone to adsorb onto silica surface hydroxyls and compete with mercapto- or polysulfidic silane grafting, which lowers bound rubber content when the compound is extracted and tested by small-strain dynamic mechanical analysis. At 1.0 phr, Mooney viscosity measured per ISO 289-1 drops by 2–5 ML(1+4) 100 °C relative to the silicone-free control without shifting scorch time measured per ISO 289-2 by more than 1 min; at 2.0 phr the demoulding force in a steam-heated bladder press at 165 °C approaches the practical lower limit, but steel cord adhesion measured per ISO 5603 and tear strength measured per ISO 36 begin to diverge from the production tolerance band. Because RH-8206 blooms to the green surface, uncured tack required for component lay-up is reduced, and accumulation on calendar creels may require roll cleaning with isopropanol after each 8 h of continuous operation. Regulatory constraints include REACH Annex XVII Entry 50 extender oil limits of 1 mg/kg benzo[a]pyrene and 10 mg/kg total eight PAHs; where the compound is to contact dry food, FDA 21 CFR 177.2600 sets extractive limits for rubber articles. End products are PCR and TBR sidewall compounds, inner liner compounds, steel-belt skim compounds, single-ply conveyor belt covers, and automotive engine mount vulcanizates.
In glass-fibre-reinforced polyamide 66 formulations for automotive electrical housings, RH-8206 is metered into the melt phase at 0.2–0.8 wt% of total compound using a positive-displacement metering pump at barrel zone 5 of a co-rotating twin-screw extruder with L/D 40:1 and vacuum venting at -0.09 MPa; barrel temperature is held between 260 °C and 280 °C, screw speed between 300 rpm and 600 rpm, and glass roving is side-fed downstream at 30 wt% loading. The long-chain alkyl substitution provides lower surface migration than unmodified dimethylsilicone oil, but the boundary condition remains: at loadings above 0.8 wt%, mould deposition on polished P20 tool surfaces becomes visible within 500–800 injection cycles, and paint adhesion after aqueous degreasing and plasma treatment declines when tested by cross-cut per ISO 2409 or pull-off per ISO 4624. Melt volume-flow rate is characterized per ISO 1133-1:2022 at 275 °C/2.16 kg, tensile properties per ISO 527-2, and heat deflection temperature per ISO 75-2. Published compound-specific data for RH-8206 in glass-filled PA66 is limited; the loading band reflects industrial practice with alkyl silicone oils of comparable chain length rather than a peer-reviewed study. Compliance boundaries are REACH Annex XVII restrictions, EU RoHS 2011/65/EU for electrical and electronic articles, and OEM specifications that often impose a maximum moulded-part volatile content of 0.3% by thermogravimetric headspace analysis. End products include injection-moulded connector bodies, cooling fan shrouds, bearing cages, and power tool housing parts.
| Application zone | Regulation / standard | Method or clause | Quantitative boundary |
|---|---|---|---|
| Tyre and rubber articles | REACH Annex XVII Entry 50 | Solvent extraction and GC/MS | Benzo[a]pyrene below 1 mg/kg; total eight PAHs below 10 mg/kg |
| Rubber food-contact articles | FDA 21 CFR 177.2600 | Extractives testing | Water and n-hexane extractive limits per rubber article class |
| Engineering plastics | EU RoHS 2011/65/EU | XRF screening / GC-MS confirmatory | Cd below 100 mg/kg; Pb, Hg, CrVI, PBB, PBDE below 1000 mg/kg |
| Polyurethane interior parts | VDA 278, ISO 6452 | Thermal desorption GC/MS, fogging chamber | OEM-specific VOC and FOG thresholds; commonly below 100 µg/g VOC |
| Textile finishing | Oeko-Tex Standard 100 Annex 4, ZDHC MRSL v3.1 | Residue extraction and LC/MS | Substance-specific residue limits per product class |
| Metalworking fluids | REACH Annex XVII, NIOSH 0500 | Mist collection and gravimetric analysis | Workplace mist exposure below regional occupational limits |
Integral skin polyurethane systems for steering wheels, gearshift knobs, armrests, and polyether-based footwear soles use RH-8206 as an internal release component in the isocyanate-reactive stream at 0.5–2.0 pphp on polyol; the diisocyanate index is maintained between 95 and 105, mould temperature between 45 °C and 65 °C, and high-pressure impingement mixing at 150 bar mixhead pressure with a 0.5–1.5 s shot time. The alkyl-modified silicone migrates to the mould surface during the first 10–20 s of foam rise, allowing demould time to be shortened by 10–20% relative to an external wax-only system without severe deposition; however, addition above 2.5 pphp creates a low-surface-energy skin layer that rejects waterborne acrylic topcoats, and cross-cut adhesion per ISO 2409 falls to zero within 72 h of ageing at 40 °C/95% relative humidity in the non-optimised condition. Volatile and fogging behaviour is monitored by VDA 278 thermal desorption GC/MS and ISO 6452 fogging; automotive interior specifications commonly require the frosted glass index to remain below 60% and total VOC below 100 µg/g, though actual thresholds are material-specification dependent. The process boundary for metering is a closed-loop mass-flow meter on the polyol line; recirculation loops must maintain 20–25 °C storage temperature to avoid viscosity drift that would alter the mixing ratio. End products are polyurethane integral skin steering wheels, gearshift knobs, armrest substrates, headrest skins, and midsole units.
In textile finishing of cotton/polyester sheeting and denim, RH-8206 is emulsified with nonionic emulsifiers at 10–30 g/L of a 20–30% oil-in-water emulsion in the finishing bath, which corresponds to 2–6 g/L active silicone solids; exhaust application on knitgoods is conducted at 1–3% on weight of fibre in a jet dyeing machine at 45–55 °C and pH 5.0–6.0, with acetic acid buffering. The finishing range uses a pad mangle at 2.5 bar linear pressure, a 70–80% pick-up on woven cotton, and stenter drying at 120 °C followed by curing at 150–170 °C for 60–90 s. Anionic auxiliaries must be pre-dispersed separately; direct mixing with cationic softening agents causes emulsion coalescence and fabric spotting that cannot be redispersed under normal shear. Fastness is assessed by ISO 105-C06 domestic laundering and colour change per ISO 105-A02; chemical management compliance follows Oeko-Tex Standard 100 Annex 4 residue limits and ZDHC MRSL v3.1. End products include peach-touch woven shirting, denim overdyed apparel, and single-jersey knit underwear.
| Sector | Typical addition | Upper addition boundary | Primary process test | Failure mode at upper boundary |
|---|---|---|---|---|
| Tyre and rubber | 0.5–2.0 phr | 2.0 phr | ISO 289-1, ISO 5603 | Steel cord adhesion and tear strength divergence |
| Glass-filled PA66 | 0.2–0.8 wt% | 0.8 wt% | ISO 1133-1:2022, ISO 2409 | Mould deposition and paint adhesion loss |
| Integral skin polyurethane | 0.5–2.0 pphp | 2.5 pphp | VDA 278, ISO 6452 | Topcoat rejection and surface porosity |
| Textile finishing | 10–30 g/L of 20–30% emulsion | 30 g/L | ISO 105-C06 | Emulsion coalescence and fabric spotting |
| Aluminium stamping fluids | 2–5 wt% of oil phase | 5 wt% | ASTM D2783, ASTM D4172 | Adhesive bond strength loss after stamping |
| Thermoplastic elastomer extrusion | 0.3–1.0 wt% | 1.0 wt% | ISO 6722, ISO 13760 | Ink adhesion failure after water immersion |
Aluminium sheet stamping of battery enclosures and heat shields uses RH-8206 as a high-temperature boundary-lubricity supplement in semi-synthetic stamping emulsions at 2–5 wt% of the oil phase; the water-diluted working fluid is maintained at 5–10% concentration, pH 8.5–9.5, and 40–50 °C sump temperature. The silicone oil deposits a shear-stable film on die radii where peak interface temperatures exceed 150 °C, the threshold at which chlorinated paraffin alternatives often lose film integrity; extreme-pressure load-carrying capacity is tracked by ASTM D2783 four-ball EP and wear scar by ASTM D4172 at 40 kgf/1200 rpm. The process constraint is post-stamp adhesive bonding: silicone-bearing residue on AA5754 or AA6061 blanks reduces epoxy adhesive lap shear strength measured per ISO 4587; therefore, parts destined for structural adhesive joining require an alkaline degrease and atmospheric plasma treatment after stamping. Regulatory constraints include REACH Annex XVII restrictions on chlorinated paraffins and the evolving PFAS restriction dossier, which favours silicone-polyether alternatives, while occupational mist exposure is monitored per NIOSH 0500. End products are aluminium battery enclosure lids, heat shields, and structural body wall panels.
Thermoplastic elastomer jackets for automotive wire and hydraulic hose covers are compounded with RH-8206 at 0.3–1.0 wt% in a single-screw extruder with L/D 25:1–30:1, barrier screw compression ratio 2.5:1, and melt temperature 180–220 °C; the silicone phase reduces die-lip build-up during 50 m/min jacket extrusion and lowers the coefficient of friction against the vacuum sizing tank water. Below 0.3 wt%, die-lip deposits return on TPV-based jacket compounds after 4–6 h of continuous running; above 1.0 wt%, ink adhesion on the finished jacket falls below the wire harness identification specification when tested by tape pull after 72 h water immersion at 23 °C. Dimensional stability is checked against ISO 6722 for automotive cable and ISO 13760 for hoses; Shore A hardness per ISO 48-4, tensile per ISO 37, and heat ageing per ISO 188 at 125 °C for 168 h are specified by the cable or hose standard. The compound must also comply with EU RoHS 2011/65/EU and REACH Annex XVII restrictions for electrical applications. End products are automotive sensor cable jackets, hydraulic hose covers, and industrial robotic cable sheaths.
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Long-chain alkyl silicone oil RH-8206 is a linear polysiloxane fluid in which a proportion of the dimethylsiloxane units are modified with long-chain alkyl groups. The alkyl fraction is not confined to terminal capping; pendent modification along the siloxane backbone influences solubility, migration behaviour, and thermal stability. The product is supplied as an essentially anhydrous, non-reactive liquid and is used as an internal lubricant, external release agent, hydrophobic surface treatment, and compatibility modifier in organic polymer systems. The material should be stored in closed containers below 40 °C; prolonged exposure to humid air can lead to silanol formation and viscosity drift.
Unmodified dimethyl silicone fluid has a solubility-parameter range that limits its compatibility with mineral oils and paraffinic carriers. The long-chain alkyl modification in RH-8206 shifts the effective solubility parameter toward 17–19 MPa0.5, from the 15.6 MPa0.5 typical of polydimethylsiloxane. That shift permits partial to complete miscibility with mineral oil at 25 °C, whereas conventional silicone fluids phase-separate. In polyethylene and polypropylene processing, the material migrates to the melt–wall interface and reduces screw torque. For a 40:1 L/D co-rotating twin-screw extruder running polypropylene at 190–210 °C, a dosage of 0.5–1.5 wt% RH-8206 has been used to improve surface finish and delay melt fracture. Torque reduction for comparable long-chain alkyl silicone fluids in that dosage window is reported in the range of 5–12%; published data for this specific configuration is limited. Above 2.0 wt%, excess lubricant can accumulate at the die lip and produce plate-out, particularly when the melt temperature exceeds 215 °C.
Rheological characterisation by cone-and-plate geometry according to ISO 3219:2021 indicates Newtonian behaviour at shear rates below 100 s-1 at 25 °C. The viscosity at 1,000 s-1 remains within 5% of the low-shear value, which distinguishes RH-8206 from high-molecular-weight silicone gum. In high-shear injection-moulding gates, the fluid acts primarily as a boundary lubricant rather than a shear-thinning polymer melt. This plateau is relevant for metering through a gear pump or side-stuffer. At temperatures below the pour point, the liquid may become cloudy but does not crystallise abruptly; the pour point is controlled to ≤-20 °C.
Batch release testing is typically performed under the methods listed below. The acceptance windows are control ranges, not absolute operating limits. Because alkyl chain distribution can vary between manufacturing lots, the viscosity window is broader than for a dimethyl silicone fluid of similar molecular weight.
| Property | Test Method | RH-8206 Acceptance Range |
|---|---|---|
| Appearance | Visual inspection | Pale yellow transparent liquid |
| Kinematic viscosity at 25 °C | ASTM D445-23 | 270–330 mm²/s |
| Density at 25 °C | ASTM D4052-22 | 0.90–0.95 g/cm³ |
| Refractive index at 25 °C | ASTM D1218-21 | 1.440–1.455 |
| Flash point, Cleveland open cup | ASTM D92-18 | ≥160 °C |
| Pour point | ASTM D97-17b | ≤-20 °C |
| Acid value | ASTM D974-22 | ≤0.10 mg KOH/g |
| Water content | ASTM D6304-20 | ≤0.10 wt% |
| Volatile content, 2 h at 150 °C | ASTM D4559-19 | ≤2.5 wt% |
These limits reduce the risk of siloxane hydrolysis and corrosion in hot tooling. Batches exceeding the volatile content upper limit have been associated with increased fogging on mould surfaces during polycarbonate injection moulding in production-scale trials; visual fogging can be evaluated according to ISO 6452:2021. If containers have been opened in a relative humidity above 60%, water content should be re-checked before use in moisture-sensitive systems.
Polyolefin injection moulding operations with clamp forces between 800 and 1,600 kN have applied RH-8206 as an external mould lubricant at dilution ratios of 1:20 to 1:50 in low-viscosity isoparaffinic solvents. The mould surface temperature is maintained below 160 °C to reduce oxidative decomposition of the alkyl groups. Release performance is evaluated using peel testing adapted from ASTM D1876-08; published data for this specific configuration is limited, but comparative studies on long-chain alkyl silicone fluids indicate a lower coefficient of friction on untreated steel than dimethyl silicone fluid of equivalent viscosity. The carrier solvent should evaporate fully before polymer injection to avoid surface defects. On textured moulds, deposition in texture valleys can occur at usage rates above 1.5 wt% in the carrier solution, requiring periodic alkaline cleaning of the tool.
The comparison in the following table is based on general industrial values for representative silicone fluid classes, not on a single RH-8206 production lot.
| Attribute | RH-8206 long-chain alkyl silicone | Dimethyl silicone fluid | Amino-functional silicone fluid | Polyether-modified silicone fluid |
|---|---|---|---|---|
| Solubility in mineral oil at 25 °C | Partial to miscible | Immiscible | Limited | Emulsifiable |
| Water solubility | Negligible | Negligible | Emulsifiable | Self-dispersible |
| Thermal stability in air | Moderate; sustained use below 180 °C | Good; sustained use below 200 °C | Moderate | Moderate |
| Typical function | Internal lubrication, release, hydrophobation | Release, surface tension reduction | Textile softening, adhesion promotion | Wetting, antistatic enhancement |
| Compatibility with polyolefins | High | Low | Low to moderate | Moderate |
| Risk of discolouration in hot processing | Low below 180 °C; increases above 220 °C | Low | Moderate due to amine oxidation | Low to moderate |
Compared with dimethyl silicone fluid of similar viscosity, RH-8206 has a lower surface tension reduction efficiency on polar substrates but better oil repellency after thermal curing. The long alkyl chains create a monomolecular film that is less mobile than PDMS but more resistant to hydrocarbon displacement. In metal corrosion preventive coatings, salt spray testing according to ISO 9227:2022 with a 2.0 wt% RH-8206 film on cold-rolled steel has shown reduced scribe creep relative to the same addition of unmodified PDMS; published data for this specific configuration is limited.
Solvent selection for RH-8206 application is governed by flash point and evaporation rate. Isoparaffinic solvents with flash points above 40 °C are preferred for dip and spray coating; low-boiling solvents increase the risk of uneven film formation. The equilibrium surface tension of long-chain alkyl silicone oils is generally in the range of 24–28 mN/m at 25 °C, which is higher than PDMS values near 20–21 mN/m. This difference reduces the tendency to form fish-eye defects on contaminated substrates, but it also means that RH-8206 is not the preferred choice when maximum spreading on low-energy substrates is required. The advantage appears in subsequent overpainting and adhesion; long alkyl groups are less surface-permanent than PDMS, allowing partial removal or interaction with topcoats.
Thermogravimetric analysis under nitrogen according to ASTM E1131-20 on representative long-chain alkyl silicone fluids shows 5% mass loss in the range of 180–220 °C at a heating rate of 10 °C/min; published data for this specific product is limited. In air, the onset of oxidative crosslinking is lower. Sustained melt temperatures above 220 °C can generate volatile alkyl fragments and siloxane decomposition products, which deposit on die faces and vacuum degassing ports. The effect is more pronounced in partially filled screw zones where oxygen is present. For nylon 6 and nylon 66 lines running at 240–270 °C, RH-8206 is not the preferred internal lubricant unless residence time is short and the dosage is kept below 0.5 wt%. At these temperatures, vacuum vent condensate load should be monitored. A processing trial with a 75 mm co-rotating twin-screw extruder at 260 °C showed that increasing the dosage from 0.5 to 1.0 wt% increased volatile condensation in the vacuum vent; published data for this specific configuration is limited.
Internal lubrication in EPDM and NBR compounds has been performed with 1.0–3.0 phr added during the first mixing pass in an internal mixer. The alkyl-modified silicone reduces mill sticking and improves filler dispersion when assessed visually according to ASTM D3182-21. Compared with paraffinic process oils, RH-8206 is used at lower loading because it migrates to the surface more rapidly. At levels above 4.0 phr, the material can exude and interfere with adhesion in rubber-to-metal bonding. Peroxide cure systems should be screened for cure inhibition before production use; sulphur cure systems are generally acceptable but require batch-to-batch confirmation.
Dip coating of woven polyester fabric with a 0.5 wt% solution of RH-8206 in isoparaffin, followed by oven curing at 120 °C for 5 min, produces a hydrostatic head increase typical of silicone hydrophobic treatment. Water contact angle measured according to ASTM D7334-08 on glass treated with a 1.0 wt% solution is in the range of 100° to 115°. The long alkyl groups reduce oil wettability, whereas conventional dimethyl silicone films are more easily swollen by hydrocarbon oils. This difference is exploited in filter media, glass fibre sizing, and moisture-resistant protective coatings. The solution should not be blended with amine-based catalysts or strongly alkaline additives because these can catalyse siloxane hydrolysis and reduce film life. If the substrate is highly acidic, adhesion may also be reduced; surface pH should be checked before application.
Regulatory data for RH-8206 should be confirmed with the supplier. Long-chain alkyl silicone oils intended for industrial use are generally assessed under REACH, but RH-8206 is not formulated as a food-grade lubricant. Applications requiring FDA 21 CFR compliance must be verified against the specific applicable section, typically 21 CFR 178.3570 for incidental food-contact lubricants; no certification is assumed for this product. For RoHS-regulated applications, the supplier’s declaration should document the absence of heavy metals and brominated flame retardants. Combinations with strong acids or alkali metal hydroxides should be avoided because siloxane bond hydrolysis can be accelerated.
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