| HS Code | 223634 |
| Productname | Silicone Rubber Adhesion Accelerator RH-GZ-03 |
| Model | RH-GZ-03 |
| Producttype | Silicone rubber adhesion accelerator |
| Appearance | Colorless to light yellow transparent liquid |
| Densityat25c | 0.95-1.10 g/cm³ |
| Viscosityat25c | 10-100 mPa·s |
| Activecontent | ≥95% |
| Solubility | Soluble in aromatic hydrocarbons, aliphatic hydrocarbons, and common organic solvents; dispersible in silicone rubber systems |
| Flashpoint | ≥60°C |
| Recommendeddosage | 0.5-2.0 phr |
| Applicationmethod | Add during silicone rubber compounding or use as a primer according to the formulation |
| Suitablesubstrates | Metal, glass, plastic, ceramic, and other substrates |
| Shelflife | 12 months in sealed original packaging |
| Storageconditions | Store in a cool, dry, ventilated place, sealed, away from moisture and direct sunlight |
| Packaging | 1 kg bottle; 5 kg drum; 25 kg drum |
As an accredited Silicone Rubber Adhesion Accelerator RH-GZ-03 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Available in 25 kg net polyethylene-lined fiberboard drums or 200 kg net plastic drums for industrial handling and storage. |
| Container Loading (20′ FCL) | RH-GZ-03 Silicone Rubber Adhesion Accelerator is container-loaded in a 20′ FCL, securely stowed and protected for sea freight. |
| Shipping | Silicone Rubber Adhesion Accelerator RH-GZ-03 ships in securely sealed, properly labeled containers via standard freight. Store and transport in a cool, dry, well-ventilated area, protected from moisture, heat, and direct sunlight. Follow the SDS and all applicable local transport regulations. |
| Storage | Store in a cool, dry, well-ventilated area away from heat, ignition sources, direct sunlight, and moisture. Keep containers tightly closed and properly labeled, using original packaging where possible. Segregate from oxidizers, acids, alkalis, and incompatible materials. Avoid freezing and contamination; follow the manufacturer’s SDS and local regulations. Do not store with food or feed. Ensure adequate ventilation and secondary containment if required. |
| Shelf Life | Typical shelf life is 12 months in original unopened packaging, stored cool, dry, and protected from direct sunlight. |
Adhesion loss between peroxide-cured high-temperature-vulcanizing silicone rubber and aramid-reinforced aluminum or stainless steel coupling rings is the principal field failure mode in turbocharged gasoline and diesel charge-air ducting. On twin-screw extruders with L/D 16–20 and roller-head die systems, a 65 Shore A HCR compound containing RH-GZ-03 at 1.2–1.8 phr is fed at 30–40 rpm, with barrel zone temperatures held at 80–95°C and the final 150 mm die head at 105–115°C. The accelerator is not introduced in the internal mixer with the silica and vinylmethyl gum because the hydrophilic alkoxy functionality hydrolyzes in the presence of free water from precipitated silica and causes early coupling. Instead, it is added on a two-roll mill at 45–50°C after the masterbatch has been cooled below 60°C and before dicumyl peroxide paste is dispersed. The production control limit is 2.0 phr; above this level, Mooney scorch at 130°C drops below 5 min and causes die-lip accumulation during continuous extrusion. Adhesion is tested per ASTM D429-14 Method B and rubber-to-metal peel per ISO 813:2019; production control specimens are aged for 168 h at 150°C in accordance with ISO 188:2023 and evaluated against the relevant coolant-hose requirements of SAE J20. Terminal products include charge-air cooler hoses, turbocharger outlet elbows, EGR cooler connecting sleeves, and coolant crossover ducts for heavy-duty diesel engines. Formulators must avoid simultaneous use of amine-containing internal release agents because the accelerator undergoes acid-base condensation with aminosilanes and reduces cohesive failure energy at the rubber-metal boundary.
In medical and respiratory device manufacturing, two-part platinum-catalyzed addition-cure LSR is overmolded onto polycarbonate, polyetherimide, or nylon 12 hubs to form catheter connectors, infusion valve bodies, and mask exhalation ports. RH-GZ-03 is dosed exclusively into the B component at 0.8–1.2 wt% before the static mixer; the A and B components are injected at a volumetric ratio of 1:1 through a 24-element static mixer at 25–35°C with an injection pressure ceiling of 500 bar to prevent flashing at the insert gate interface. Higher loadings in the B component increase the low-molecular-weight silanol extractable fraction and complicate compliance with ISO 10993-18:2020 and USP <88> Class VI; therefore the upper formulation boundary is set at 1.2 wt% unless a supplementary vacuum devolatilization step is adopted. The overmolding process operates at a mold temperature of 120–140°C with a cure time of 25–45 s for a 40 Shore A LSR, and insert preheating to 110°C is used for PEI substrates to reduce residual moisture below 0.02%. Adhesion to the polymer hub is verified by peel testing following ASTM D903 with 180° peel rate of 50 mm/min after steam sterilization at 134°C for 3 min per ISO 17665-1:2006. Terminal component types include luer-lock catheter hubs, enteral feeding connector bodies, CPAP mask exhalation ports, and overmolded LSR diaphragms in drug delivery devices. The product must not be formulated with tin-catalyzed condensation cure systems because residual tin species coordinate with alkoxy groups and suppress the platinum catalyst, leading to surface tack after molding.
Crack initiation at the interface between fiberglass-reinforced epoxy core and high-temperature-vulcanized silicone sheds on composite insulators is controlled by the silane coupling efficiency of the first layer of rubber applied to the core during injection molding or transfer molding. A standard line-post or suspension insulator formulation uses a 50 Shore A HTV silicone with alumina trihydrate filler, and RH-GZ-03 is compounded at 1.0–1.6 phr after the ATH has been hydrophobized and the batch temperature has fallen below 70°C. The compound is then injected into a mold heated at 170–180°C under a clamp force sufficient to maintain 120–180 bar cavity pressure; cure time ranges from 8–15 min depending on wall thickness. Accelerator dosing above 1.8 phr produces an excessively stiff interface layer that shows crosslinked rubber tear rather than cohesive failure along the FRP core during the 90° peel test, whereas dosing below 0.8 phr results in clean interfacial separation after salt-fog ageing per IEC 62217:2012 and hydrophobicity transfer testing under IEC TS 62073. Production control includes tracking and erosion resistance per IEC 60587, adhesion testing per ASTM D429-14 Method A, and thermal ageing per IEC 61109:2008. Terminal products are composite suspension insulators, line post insulators, surge arrester housings, and hollow-core insulator bodies for cable terminations. Field observations from mandrel peel tests on 1 m production cores show that interfacial failure is most common when the core temperature at injection is below 80°C, because condensation of silanol groups is diffusion-limited and incomplete at the interface boundary.
During high-speed insert molding of LSR onto heat-stabilized PA66 or PBT electrical connector bodies, adhesion failures appear only after thermal shock cycling because the differential linear expansion between the silicone and the thermoplastic reaches 0.3–0.5% at 150°C peak air temperature. RH-GZ-03 is pre-blended with the LSR B component at 0.5–1.0 wt%; the mixed viscosity must not exceed 45 Pa·s at 10 s⁻¹ and 25°C, otherwise the material no longer fills 0.3 mm seal beads without wire-edge flash. Production injection units use a 120 kN mold clamp for eight-cavity connector tools, a barrel temperature of 20–25°C, and a cold-runner set point of 18°C; the heated mold is held at 140–160°C. Adhesion is characterized by a 90° peel test on overmolded plaques according to ISO 813:2019, while finished connectors are tested for sealing under IEC 60529 IP67 and electrical safety under IEC 60664-1. Terminal parts include sealed automotive connectors, battery sensor housings, outdoor LED connector boots, and electronic throttle body gaskets. The formulation is incompatible with halogenated flame retardants that generate acidic volatiles at the mold surface because these volatiles protonate the alkoxy coupling group and inhibit bonding to PBT; a bake-out at 90°C for 2 h is required for any substrate that has been stored at ambient humidity above 60% RH.
On continuous dip-coating and knife-over-roll lines, fiberglass sleeves and fabrics are coated with peroxide-cured HCR silicone in a continuous vulcanization oven, and delamination on flexing is the primary control endpoint. A coating compound formulated at 1.5–2.0 phr RH-GZ-03 is dispersed in a 65 Shore A gum after silica addition, then applied to heat-cleaned fiberglass fabric at a coat weight of 250–400 g/m² and cured in a 4–6 m tunnel at 180–220°C for 3–6 min depending on line speed. The additional accelerator at this level is necessary because the original fiberglass finish must be removed by pre-baking at 400°C for 30 s; without the higher dosage, uncoupled silanol groups are insufficient to wet the exposed silanol sites on the glass surface. Adhesion is measured by flex-fold testing and peel adhesion per ASTM D751 after thermal ageing per ISO 1419; for fire protection sleeves, the finished product is further evaluated under ISO 15540:2016 flame resistance and the relevant performance clauses of SAE AS1072. Terminal products include silicone-coated fiberglass fire sleeves for fuel line protection, removable insulation blankets, expansion joint fabric, and heat-resistant conveyor belts for glass tempering lines. Above 2.0 phr, the cured fabric develops surface haze from silane migration and the tear strength measured by ASTM D624-00 drops below the specified minimum in insulation blanket applications.
For single-core wires and multi-conductor cables insulated with silicone rubber, controlled adhesion to tinned copper or silver-plated conductors prevents moisture wicking along the stranding while still allowing clean manual stripping. RH-GZ-03 is added to a 60 Shore A peroxide-cured silicone insulation compound at 0.8–1.3 phr on a two-roll mill before dicumyl peroxide paste; the mixed compound is extruded onto 18 AWG tin-plated copper stranding using a 90 mm extruder with an L/D of 20:1, screw speed 20–30 rpm, and head temperature of 110–120°C. The subsequent continuous vulcanization line uses a 2.0–2.5 MPa saturated steam section of 6 m length and a post-cure oven at 200°C for 2 h to complete volatile elimination. Accelerator loading above 1.3 phr causes a measurable drop in conductor-to-insulation peel force because excess coupling agent migrates to the copper surface and forms a stiff, microcracked interphase after thermal cycling from -40°C to 200°C. Compliance testing includes vertical flame spread per IEC 60332-1-2, halogen acid gas per IEC 60754-1, smoke density per IEC 61034-2, and restricted substances under 2011/65/EU. Terminal wire and cable types include silicone-insulated appliance wiring, high-temperature motor lead wire, railway rolling stock cables, and aerospace airframe wire where the conductor is silver-plated copper. For silver-plated conductors, a lower addition of 0.5–0.8 phr is used because silver sulfide formation potential and interphase reflectivity changes are controlled by limiting migratable silane species.
Competitive Silicone Rubber Adhesion Accelerator RH-GZ-03 prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8618005193850 or mail to sales8@bouling-chem.com.
We will respond to you as soon as possible.
Tel: +8618005193850
Email: sales8@bouling-chem.com
Flexible payment, competitive price, premium service - Inquire now!
RH-GZ-03 is supplied as a solvent-free, oligomeric organosilane adhesion accelerator for platinum-catalyzed addition-cure liquid silicone rubber (LSR) and peroxide-cured high-consistency rubber (HCR). The product is introduced at 0.5–2.0 phr during compound preparation or through a static-mixer feed stream, where it modifies wetting on polyamide, polybutylene terephthalate, aluminum, stainless steel, and glass. Unlike monomeric vinyltrimethoxysilane, RH-GZ-03 exhibits a higher flash point and lower vapor pressure, reducing volatile organic compound release during open-mill mixing and mold venting. Representative physicochemical data are provided in Table 1; the values are class-typical for the supplied chemistry and must be confirmed against the batch certificate of analysis.
| Property | Method | Representative value |
|---|---|---|
| Appearance | Visual inspection | Clear to pale yellow liquid |
| Density at 25 °C | ASTM D792 | 0.98–1.05 g/cm³ |
| Viscosity at 25 °C, Brookfield | ASTM D2196 | 20–80 mPa·s |
| Refractive index at 25 °C | ASTM D1218 | 1.420–1.450 |
| Flash point, closed cup | ASTM D93 | >90 °C |
| Volatile organic compounds | ISO 11890-2 | <1.0 wt% |
| Water content | ISO 15512 | <0.1 wt% |
| Nonvolatile residue | ASTM D2369 | >98 wt% |
| Solubility | Solvent test | Soluble in xylene, toluene, acetone; hydrolyzes in water |
Storage life in unopened containers is typically 12 months from the date of manufacture when kept below 30 °C and protected from atmospheric moisture. The material hydrolyzes slowly in humid air and generates methanol; feed systems should therefore be closed or nitrogen-blanketed. RH-GZ-03 is added before the platinum catalyst and after fumed-silica wetting in silica-filled LSR to limit silanol adsorption on filler surfaces.
The oligomeric organosilane operates through dual reactivity. Alkoxysilyl groups hydrolyze at the substrate interface with adsorbed water to form silanol intermediates, while the vinyl functionality participates in Si-H addition during platinum cure. In platinum-catalyzed LSR, the terminal vinyl function of the oligomeric silane competes with silicone polymer vinyl groups at the Pt(0) active center. Because the oligomeric silane has lower steric accessibility than the base vinylmethylsiloxane polymer, cure inhibition is not typically observed below 2.0 phr. Above 3.0 phr, the apparent degree of cure may decrease because the accelerator acts as a chain-transfer or diluent site.
Moving die rheometer data at 120 °C in accordance with ASTM D5289 for a 40 Shore A LSR containing 1.0 phr RH-GZ-03 typically indicate a tc90 shift of less than 10 s relative to the unfilled control. At 2.5 phr, tc90 may increase by 20–40 s, and minimum torque S′min may fall by 0.5–1.5 dN·m. These values are class-typical for oligomeric vinylsilane accelerators; published data specific to RH-GZ-03 are limited, and internal rheometer characterization on the production compound is required before cycle-time adjustment.
The accelerator does not contain organotin or amine catalysts, so platinum inhibition is not expected from the accelerator chemistry itself. However, sulfur-containing mold release agents must be excluded because surface contamination below 0.1 ppm can poison the Pt(0) active center and increase tc90 or prevent complete cure. In dry molding environments with a dew point below -10 °C, adhesion development may be incomplete because silanol formation requires adsorbed water. Preconditioning substrates in standard atmosphere 23 °C/50% RH per ISO 291 for 4–24 h before overmolding improves condensation without producing bulk water films. On aluminum or glass, silanol condensation forms Si-O-Al or Si-O-Si bonds at the interface. On polyamide and polybutylene terephthalate, hydrogen bonding and mechanical interlock dominate because the density of surface hydroxyl groups is lower.
At addition levels above 2.5 phr, storage modulus G′ at 25 °C can decrease because the oligomeric silane introduces chain ends and reduces crosslink density. Dynamic mechanical analysis per ISO 6721-1 on cured specimens shows a drop in rubbery plateau modulus of approximately 5–15% at 3.0 phr, depending on base vinyl content. Hardness per ASTM D2240 may fall by 3–7 Shore A points, and compression set per DIN ISO 815-1 after 22 h/150 °C can increase by 5–10 percentage points. These changes are class-typical and indicate that the accelerator is not an inert filler; it perturbs the hydrosilylation stoichiometry and must be accounted for in the formulation silane-to-vinyl balance.
In liquid silicone rubber injection molding with clamp force between 100 t and 350 t and mold temperature between 120 °C and 180 °C, RH-GZ-03 is injected as a separate additive stream into a static mixer having 12–24 elements and a nominal diameter of 6–12 mm. Metering accuracy of ±0.05 phr is required for consistent adhesion; Coriolis mass flow metering per ISO 10790 or precision piston dosing is preferred. Backpressure in the mixing manifold is held at 5–15 MPa for high-shear dispersion. Insufficient backpressure produces silane-rich domains that exude to the surface during cure and leave a tacky film. Cleanout of residual RH-GZ-03 from static mixers should occur within 24 h of shutdown using xylene or silicone oil; otherwise the material hydrolyzes in humid air and hardens in the mixer elements.
In silica-filled LSR, the adhesion promoter should be added after filler wetting. Fumed silica with high surface silanol density can adsorb the oligomeric silane and reduce the effective interfacial concentration by as much as 30–50%. If addition is made before hydrophobization is complete, batch-to-batch adhesion variation is observed. High-shear mixing above 60 °C should be avoided when water content exceeds 0.1 wt%; premature hydrolysis forms siloxane oligomers that cannot condense at the substrate. The batch temperature should be held below 50 °C during additive incorporation. Formed-in-place gaskets and cured-in-place gaskets use RH-GZ-03 at the lower end of the dosage range, typically 0.5–1.0 phr, because high surface-to-volume ratios accelerate silane migration and can deplete bulk adhesion promoter before cure. Dispensing through a 0.2–0.6 mm needle with a volumetric metering system is common; the additive should pass through a 100 μm filter before final dispensing to remove hydrolyzed agglomerates.
Primerless bonding is specified for automotive connector gaskets, LED module seals, and overmolded sensor housings. Adhesion is evaluated by lap shear per ASTM D3163 on 6061-T6 aluminum, by ASTM D429 Method B for rubber-to-metal assemblies, and by ISO 4624 pull-off for glass and coated substrates. The target failure mode is 100% cohesive failure within the silicone phase. If adhesive failure occurs at the substrate, the RH-GZ-03 addition level should be raised in 0.5 phr increments to a maximum of 2.5 phr before substrate preparation is reevaluated.
Polyamide 6,6 with 30 wt% glass fiber and PBT components must be free of mold-release residues. Alkaline detergent washing followed by drying at 80 °C for 2 h per ISO 1110 reduces surface contamination and internal moisture. Adhesion promoters alone cannot compensate for polydimethylsiloxane-based external release agents. Plasma or dry-ice blasting is used when washing is not permitted; the surface energy should exceed 40 mN/m as measured by contact angle before overmolding. On polybutylene terephthalate, monomeric vinyl silanes can migrate into the surface layer and plasticize the matrix, causing haze and stress cracking after thermal aging. The oligomeric structure of RH-GZ-03 has a lower diffusion coefficient and reduces this failure mode. Dynamic mechanical analysis of PBT exposed at 85 °C for 7 days shows no significant glass transition shift at an addition level of 1.5 phr; published data for this specific configuration is limited, and final part approval requires testing on the production substrate batch.
Post-cure at 200 °C for 2 h is often applied to drive residual silanol condensation and improve adhesion to glass and metal. Typical injection speed for LSR overmolding is 1–5 cm³/s per cavity, with holding pressure 20–60% of peak injection pressure. Flash-free parting-line adhesion requires mold temperature at the substrate above 120 °C; below this temperature, the silane condensation rate slows and the LSR may cure before interfacial wetting is complete.
Vinyltrimethoxysilane has a closed-cup flash point near 28 °C and emits one molar equivalent of methanol upon hydrolysis; methacryloxypropyltrimethoxysilane has a flash point near 46 °C. RH-GZ-03, with a flash point above 90 °C, is less volatile during open mixing at 40 °C and reduces methanol emission by more than 80% at equal silane equivalent weight when tested by ISO 11890-2. In platinum-catalyzed LSR, monomeric vinyl silane can cause surface tack and evaporative loss before cure; methacryloxy silane does not co-cure through hydrosilylation and can act as a plasticizing diluent at addition levels above 0.5 phr.
| Parameter | RH-GZ-03 | Vinyltrimethoxysilane | Methacryloxypropyltrimethoxysilane |
|---|---|---|---|
| Functional group | Oligomeric vinyl silane | Monomeric vinyl silane | Monomeric methacryloxy silane |
| Flash point, closed cup, ASTM D93 | >90 °C | 25–30 °C | 46 °C |
| Methanol release | Low | High | High |
| Volatility in open mixing at 40 °C | Low | High | Moderate |
| Platinum cure compatibility | Suitable to 2.0 phr | Fair; tack risk above 0.5 phr | Poor; not recommended |
| Adhesion to PBT and polyamide | High | Moderate | Low |
| Use in peroxide-cured HCR | Possible | Possible | Preferred |
Comparative values are compiled from supplier technical data sheets for standard monomeric silanes and from class-typical data for oligomeric vinylsilane accelerators. Batch-specific results should be verified with the production LSR because filler type, inhibitor concentration, and mold temperature shift the threshold for tack and cure delay.
For storage and regulatory control, RH-GZ-03 is supplied in 20 kg HDPE pails and 200 kg steel drums with nitrogen-blanketed headspace. Storage should be maintained below 30 °C in closed containers; exposure to atmospheric moisture reduces activity through premature hydrolysis. The material should not be mixed with amine-functional silanes, tin condensation catalysts, or sulfur-containing release agents. For food-contact silicone elastomers, the final cured article must be tested under FDA 21 CFR 177.2600 and EU Regulation 10/2011 as appropriate; RH-GZ-03 itself is not a direct food-contact additive. REACH registration status and SVHC content below 0.1 wt% must be verified against the current safety data sheet and IEC 63000 technical documentation. RoHS compliance of the final overmolded assembly requires testing for restricted phthalates and heavy metals per IEC 62321-5 and IEC 62321-8.
Dedicated to excellence in chemistry — serving industries worldwide with integrity and innovation.
