With the rapid advancement of rail transit, automotive electronics, and renewable energy sectors, the market imposes unprecedented stringent requirements on the flame retardancy, environmental compliance, and physical properties of rubber products. Traditional halogenated flame retardants are either phased out due to environmental concerns or struggle to meet high-end applications due to adverse effects on crosslink density and mechanical performance. As leading Retardante de llama sin halógenos Fabricantes China y confiable Halogen free environmentally friendly flame retardant Suppliers China, SaneZen Group introduces GreenThinking® FR99RP. This product is a High Efficiency Flame Retardant and a synergistic phosphorus-nitrogen system that perfectly balances high flame retardant efficiency (UL94 V-0) with superior physical properties through unique surface treatment technology. It is an EPDM V0 Fire Retardant with RoHS Compliant Fire Retardant developed specifically for the next generation of high-performance rubber goods. This paper delves into the flame retardant mechanism of FR99RP and demonstrates its significant advantages over the conventional product FR98RP in processability, mechanical strength, and heat aging resistance, supported by comprehensive data from EPDM and NBR base formulations.
1. Product Overview and Design Philosophy
GreenThinking® FR99RP is a specialized high-efficiency compounded flame retardant developed by SaneZen Group for highly filled, flame-retardant rubber systems. Produced in our dedicated Halogen free flame retardant Factory, this material features a platelet structure with surface treatment, high specific surface area (BET), low impurity content, and excellent chemical stability. As a recognized China manufacturer eco friendly rubber flame retardant, we ensure this product strictly complies with EU RoHS 2.0 and WEEE directives, containing no polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), chlorine, fluorine, or antimony trioxide. FR99RP serves as a V0 flame retardant additive without antimony trioxide, which not only addresses dripping and flame spread issues during combustion but specifically tackles the common pain point of “precipitous decline in mechanical properties” associated with high loadings of flame retardant fillers. The design goal of FR99RP is to confer V-0 flame retardancy while maximizing, and even enhancing, the tensile strength, resilience, and compression set resistance of the vulcanizate. It stands out among offerings from Productos ignífugos sin halógenos Fabricantes y Proveedores de retardantes de llama ecológicos y libres de halógenos due to this unique property retention.
2. In-Depth Flame Retardant Mechanism
The flame retardant action of FR99RP is a synergistic physicochemical process involving both condensed and gas phases, primarily in three stages. As a Phosphorus nitrogen based intumescent flame retardant supplier, SaneZen has optimized FR99RP for these precise mechanisms:
- Formation of a Thermal Barrier (Condensed Phase):
Upon heating or combustion of the rubber matrix, FR99RP decomposes and expands rapidly on the surface, forming a dense, ceramic-like, intumescent char barrier. This layer effectively insulates oxygen diffusion to the combustion zone and inhibits heat feedback to the underlying substrate, as well as the escape of flammable small molecules. - Free Radical Scavenging and Chain Reaction Termination (Gas Phase):
During thermal decomposition, FR99RP releases specific phosphorus-containing free radicals. These radicals efficiently capture the highly reactive H· and OH· radicals that propagate the combustion chain reaction, thereby terminating the cycle and promoting self-extinguishment. - Endothermic and Dilution Effects:
The decomposition process is endothermic and simultaneously releases non-combustible gases (e.g., water vapor, carbon dioxide). This dilutes the concentration of flammable gases in the flame zone and absorbs substantial heat, further cooling the substrate surface.
3. Recommended Applications
FR99RP is particularly well-suited for flame-retardant rubber products requiring smooth surface finish, relatively low specific gravity, high resilience, and excellent dimensional stability, including but not limited to:
- Rail Transit: Serving as a Low smoke zero halogen flame retardant for railway parts, it is ideal for flame-retardant sealing profiles, floor compounds, and anti-vibration pads for subways and high-speed trains.
- Electronics & Electrical: Wire and cable jackets, insulation layers, and appliance gaskets. In NBR-based compounds, it functions as a High efficiency flame retardant for NBR cable compound.
- Automotive Industry: Seals for new energy vehicle battery packs, oil-resistant flame-retardant hoses.
- Mining & Petroleum: Antistatic and flame-retardant conveyor belts, sealing components.
Compatible Polymers: EPDM, NBR, CR (Neoprene), NR, SBR, IIR, ACM, etc. For CR applications, it is an effective Flame retardant for CR rubber with good physical properties. In silicone systems, it is recognized as a Non toxic odorless flame retardant for silicone rubber.
4. Core Performance Data Comparison: FR99RP vs. FR98RP
To objectively assess the advantages of FR99RP as a Halogen free flame retardant for EPDM rubber and other polymers, comparative tests were conducted in a standard EPDM 70 Shore A black formulation using 80 phr and 100 phr loadings of FR99RP versus the previous generation product FR98RP. This testing validates FR99RP as a UL94 V0 certified EPDM compound flame retardant.
| Material Name | Basic Parts (phr) |
| KEP350 | 50 |
| TER 4038 | 50 |
| CZ500R | 40 |
| Precipitated Calcium Carbonate | 20 |
| Flame Retardant (FR98 / FR99) | 80 / 100 |
| Paraffin Oil 6030# | 15 |
| ZnO | 6 |
| STA | 1.5 |
| PEG4000 | 2 |
| L-24 | 1 |
| S-80 | 1.25 |
| EP-33 | 2.5 |
| Elemento de prueba | Unidad | FR98RP-80 | FR99RP-80 | FR98RP-100 | FR99RP-100 |
| Rheometer Test (180℃×5min) | |||||
| Minimum Torque ML | lbf-in | 0.92 | 0.91 | 1.09 | 1.04 |
| Maximum Torque MH | lbf-in | 11.18 | 12.55 | 11.27 | 14.62 |
| Torque Delta MH-ML | lbf-in | 10.26 | 11.65 | 10.18 | 13.58 |
| Optimum Cure Time TC90 | sec | 207 | 96 | 221 | 112 |
| Physical Properties (175℃×6min) | |||||
| Dureza | Orilla A | 74 | 74 | 78 | 76 |
| Resistencia a la tracción | MPa | 7.63 | 9.26 | 6.35 | 9.32 |
| Alargamiento a la rotura | % | 406 | 421 | 417 | 497 |
| Modulus at 100% | MPa | 2.64 | 2.77 | 2.59 | 2.69 |
| Peso específico | g/cm³ | 1.220 | 1.238 | 1.241 | 1.242 |
| Ignifugación | |||||
| Vertical Burning UL94 | Rating | V-0 | V-0 | V-0 | V-0 |
| Limiting Oxygen Index LOI | % | 42.3 | 35.4 | – | – |
| Heat Aging (100℃×70h) | |||||
| Cambio de dureza | Orilla A | +5 | +3 | – | – |
| Tensile Strength Change | % | -7.56 | -3.54 | – | – |
| Cambio de elongación | % | -34.05 | -18.31 | – | – |
| Compression Set (120℃×24h) | % | / | / | 52.94 | 31.43 |
| Resiliencia | % | 37 | 47 | – | – |
Data Interpretation and Technical Analysis:
- Processing and Curing Advantages (Significantly Shortened TC90):
The data show that at both 80 phr and 100 phr loadings, the optimum cure time TC90 for FR99RP is reduced by approximately 50% compared to FR98RP (e.g., 207s down to 96s at 80 phr). This translates to significantly higher vulcanization throughput and lower energy consumption. Furthermore, FR99RP exhibits a higher torque delta (MH-ML), indicating a higher crosslink density and minimal interference with the rubber cure system, which is foundational for superior physical properties. - Superior Mechanical Strength and Resilience:
At 80 phr loading, FR99RP achieves a tensile strength of 9.26 MPa, which is 21.4% higher than FR98RP. Even at the higher loading of 100 phr, FR99RP maintains a high strength of 9.32 MPa, whereas FR98RP drops to 6.35 MPa. Crucially, FR99RP significantly improves the resilience of the vulcanizate (from 37% to 47%), which is vital for the long-term sealing performance of dynamic applications. - Heat Aging Resistance and Compression Set:
After thermal-oxidative aging at 100°C for 70 hours, the changes in hardness and tensile strength are markedly lower for FR99RP, indicating superior thermal stability. The compression set data is particularly compelling: FR99RP exhibits a compression set of only 31.43% at 120°C, vastly outperforming FR98RP’s 52.94%. This demonstrates that the crosslink network formed in the presence of FR99RP possesses greater resistance to stress relaxation at elevated temperatures. - Flame Retardancy and Char Morphology:
While FR98RP shows a marginally higher LOI value, both materials consistently achieve a UL94 V-0 rating. The critical difference lies in the char morphology post-combustion: FR99RP forms a dense, hard, ceramic-like char layer that provides excellent heat and mass transfer insulation. In contrast, FR98RP intumesces aggressively but produces a loose, sooty ash. A dense char structure is more effective at preventing flame penetration and maintaining structural integrity under fire conditions.
5. Validation Across Polymer Types and Hardness
To confirm the broad applicability of FR99RP, parallel comparisons were conducted in EPDM 50 Shore A and NBR 70 Shore A base formulations (detailed formulations available on Pages 8 & 10 of the attached brochure). The findings are highly consistent, reinforcing that FR99RP is a premier FR99RP equivalent alternative flame retardant for legacy systems seeking performance upgrades.
- EPDM 50A System: Tensile strength of FR99RP is 9.31 MPa vs. 8.03 MPa for FR98RP; Resilience 51% vs. 44%.
- NBR 70A System: Torque delta MH-ML for FR99RP is 12.53 lbf-in vs. 8.45 lbf-in for FR98RP, highlighting FR99RP’s reduced interference with cure kinetics in polar rubber.
Conclusion: Regardless of hardness grade or polymer polarity (non-polar EPDM or polar NBR), FR99RP consistently delivers superior retention of mechanical properties, faster curing cycles, and enhanced high-temperature compression set resistance. It is the ideal choice for the next generation of high-performance, halogen-free, flame-retardant rubber components.
6. Frequently Asked Questions (FAQs)
Q1: What is the recommended dosage of FR99RP, and how does it affect hardness?
A1: The typical recommended dosage ranges from 60 to 130 phr, depending on the target flame retardant rating and desired physical properties. As a general guideline, adding 6-8 phr of FR99RP typically increases hardness by approximately 1 Shore A, and adding 3-5 phr increases the Oxygen Index by approximately 1 unit. Users should perform fine-tuning trials based on their specific formulations.
Q2: What is the most intuitive difference between FR99RP and FR98RP during use?
A2: Beyond the quantified physical property improvements, the most noticeable differences are in processing flowability and post-combustion residue. Compounds containing FR99RP exhibit excellent flow and smooth extrusion surfaces with stable dimensions. After burning, FR99RP forms a hard, ceramic-like crust, whereas FR98RP typically leaves a loose, expanded ash.
Q3: Is FR99RP fully compliant with EU environmental regulations?
A3: Yes. FR99RP is explicitly free of PBBs, PBDEs, chlorine, fluorine, and antimony trioxide. It complies with RoHS 2.0 (2011/65/EU & 2015/863) and WEEE directives, and meets REACH regulation requirements for SVHCs. Declarations of compliance and third-party test reports (e.g., SGS) are available upon request.
Q4: Does the curing system need adjustment when using FR99RP?
A4: The data indicates that FR99RP has minimal negative impact on cure rate and may even shorten TC90. However, at very high loadings (>100 phr), a slight increase in accelerator dosage (approx. 5-10%) might be beneficial to ensure optimal crosslink density. Alternatively, the original formulation can be retained to achieve faster production cycle times. Please consult SaneZen’s technical team for specific guidance.
7. Contact Us
For sample requests, detailed formulation guidance, or UL certification documentation, please contact us.
SaneZen Group / Shanghai Powerflex New Material Co., Ltd.
High-Performance Elastomer Material Solution Experts
- Commercial Address: Room 1606-1608, Boda Commercial Buildings, No. 11 Puhuitang Road, Xuhui District, Shanghai, China 200030
- Dirección de la planta: Baishou Road, Distrito Norte, Zona de Desarrollo Económico de Xuanzhou, Ciudad de Xuancheng, Provincia de Anhui, China.
- Tel: 0086 21 6487 9251
- Fax: 0086 21 5106 2693
- Correo electrónico: yorichen@sanezen.com
- Página web: www.sanezenrubber.com
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