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Send EmailMicroencapsulated Red Phosphorus Powder, Coated Red Phosphorus Glue, Fluid Paste, RPL, 7723-14-0
Microencapsulated Powder (P₄) and Molecularly Modified Fluid Paste (RPL) Technologies.
| Parameter | Description |
|---|---|
| Product Types | 1. Microencapsulated Red Phosphorus Powder 2. Coated Red Phosphorus Glue / Fluid Paste (RPL) |
| Chemical Family | Elemental Phosphorus Allotrope / Inorganic Flame Retardant Synergist |
| General Characterization | The hygroscopicity, unstable ignition, and poor interfacial compatibility of pure red phosphorus with polymer matrices have been completely passivated through advanced multi-layer microencapsulation and molecular modification technologies, making them suitable for industrial use. |
The products consist of elemental red phosphorus particles coated with a thin protective wall layer (thermoset resin and inorganic metal hydroxides), or a stable suspension of these particles in a liquid carrier phase.
| Parameter | Value | Source/Note |
|---|---|---|
| CAS Registry Number | 7723-14-0 | PubChem |
| Molecular Formula | P₄ (Pₙ in polymeric chain structure) | — |
| Effective Phosphorus Concentration (Powder) | ≥ 85.0% (by weight) | Document data |
| Effective Phosphorus Concentration (Paste/Glue) | 45.0% – 55.0% (by weight) | Document data |
| EC Number | 231-768-7 | Merck SDS |
| Index Number | 015-002-00-7 | Merck SDS |
Structural Significance: Pure red phosphorus exhibits several drawbacks regarding thermal instability, strong moisture absorption, and reddish-brown color, which restrict its commercial applications. Surface treatments, typically inorganic and polymeric microencapsulation, are required . Advanced multi-layer encapsulation completely isolates elemental phosphorus from direct air contact, preventing smoking or premature oxidation during high-temperature drying, injection, and curing ovens.
| Property | Powder Form | Paste/Glue Form (RPL) |
|---|---|---|
| Appearance | Red colored, fine and free-flowing powder | Dark red, homogeneous fluid paste |
| pH Value (10% aqueous suspension) | 6.0 – 7.5 | 6.0 – 8.0 |
| Dynamic Viscosity | — | 3000 – 7000 mPa·s (at 25°C) |
| Water Solubility | Practically insoluble | Practically insoluble |
| Ignition Point | 320°C | — |
Verified Data Note: Pure red phosphorus ignites in air at approximately 260°C , and safety data sheets report an ignition point of 280°C . The encapsulated product's ignition point of 320°C represents a significant thermal stability improvement attributable to the protective coating.
| Parameter | Value | Source/Note |
|---|---|---|
| Ignition Point (Powder) | 320°C | Document data |
| Thermal Stability | Multi-layer continuous coating architecture prevents smoking or premature oxidation in high-temperature ovens | Document data |
| Processing Limit | Safely processed in engineering plastics at melt temperatures < 300°C | Document data |
Mechanism Note: The protective wall layer isolates elemental phosphorus from direct air contact. Literature confirms that microencapsulation significantly improves the thermal stability and reduces moisture absorption of red phosphorus .
| Parameter | Powder Form | Paste Form (RPL) |
|---|---|---|
| Fineness | 1500 – 2500 mesh ultra-fine micronized | D₉₇ ≤ 150 μm |
| Matrix Dispersion | Ultra-fine structure prevents agglomeration in plastic melt | 3000–7000 mPa·s viscosity prevents sedimentation in liquid polymer dispersions |
The product series forms a superior flame retardant barrier even at very low dosages due to its high phosphorus concentration:
Engineering Plastics (Powder Form): Used as primary FR in glass fiber reinforced PA6/PA66 and PBT matrices for electrical switches, fuse holders, and bobbin cores.
Technical Textiles and Coatings (Paste/Glue Form): Integrated into acrylic or polyurethane-based back-coating formulations for military tents, heavy industrial conveyor belts, and protective clothing.
Elastomers and Cables (Powder Form): Provides high fire resistance without compromising mechanical properties in EPDM, diene rubbers, EVA, and EEA-based halogen-free (HFFR) flexible cable sheaths.
Adhesives and Mastics (Paste/Glue Form): Used in intumescent fire insulation paints, sealant mastics, and epoxy encapsulation resins in construction and automotive sectors.
Aesthetic and Color Restriction: Due to the natural purplish-red pigment character, the products are not suitable for transparent, white, or light-colored (pastel) products. Designed for dark-colored or black industrial segments.
Verified Application Note: Literature confirms that microencapsulated red phosphorus (MERP) in PA66 and glass fiber reinforced PA66 achieves satisfactory flame retardancy and mechanical performance. The nitrogen-phosphorus (N-P) synergistic effect between the MCA coating and red phosphorus significantly improves flame retardancy .
| Process/Application Type | Powder Form (≥85% P) | Paste/Glue Form (~50% P) | Selection Rationale |
|---|---|---|---|
| Thermoplastic Extrusion/Injection | Excellent | Not Suitable | Powder feeding and high melt shear in twin-screw extruders require powder form |
| Textile Back-Coating | Not Suitable | Excellent | Prevents dust dispersion; homogeneous mixing in liquid acrylic and PU emulsions |
| Liquid Epoxy/PU Casting | Limited | Excellent | Enables bubble-free, sedimentation-free casting while maintaining viscosity |
| Rubber Compounding (Banbury Mixer) | Excellent | Limited | Enables rapid mechanical incorporation of high phosphorus concentration into rubber compound |
| Intumescent Passive Fire Paints | Limited | Excellent | Liquid phase preserves film-forming ability and smooth surface aesthetics |
Magnesium Hydroxide (Mg(OH)₂) or Aluminum Hydroxide (Al(OH)₃) can be used as flame retardant synergists. General dosage range is 4.0% – 10.0% by weight.
Recipe A: Glass Fiber Reinforced Polyamide 66 (Powder Form)
| Component | wt% |
|---|---|
| PA66 Matrix (Pure Engineering Grade) | 64.45 |
| Encapsulated Red Phosphorus Powder | 5.00 |
| Glass Fiber (Chopped - Engineering Grade) | 30.00 |
| Zinc Stearate (Process Aid / Mold Release) | 0.40 |
| AO 1010 / AO 168 (Heat and Process Stabilizer) | 0.10 |
| Carbon Black (Black Pigment) | 0.05 |
| Target Fire Standard | UL 94 V-0 (1.6 mm) |
Recipe B: Acrylic-Based Technical Textile Back-Coating (Paste/Glue Form)
| Component | wt% |
|---|---|
| Acrylic Emulsion (Liquid Polymer Binder) | 60.0 |
| Coated Red Phosphorus Glue (RPL) | 12.0 |
| Aluminum Trihydrate (ATH - Inorganic Synergist) | 8.0 |
| Formulation Water / Diluent | 18.5 |
| Defoamer and PU-Based Thickener (Rheology Agent) | 1.5 |
| Target Fire Standard | BS 5852 / EN ISO 15025 |
Recipe C: Fire-Resistant Structural Mastic and Electronic Encapsulation (Paste/Glue Form)
| Component | wt% |
|---|---|
| Liquid Epoxy Resin or Modified Silicone Polymer | 45.0 |
| Coated Red Phosphorus Glue (RPL) | 10.0 |
| Magnesium Hydroxide (MDH - Mineral Filler/Synergist) | 22.0 |
| Quartz Powder or Functional Calcite | 20.0 |
| Hardener Catalyst / Rheology Modifier | 3.0 |
| Target Fire Standard | UL 94 V-0 |
| Parameter | Assessment | Source/Note |
|---|---|---|
| Classification | Advanced encapsulation suppresses the high reactivity of elemental phosphorus. However, based on flammable solid nature and aquatic effects, evaluated under H228 (Flammable solid) and H412 (Harmful to aquatic life with long lasting effects) criteria | PubChem ; Merck SDS |
| Signal Word | Warning | PubChem |
| Hazard Statements | H228: Flammable solid H412: Harmful to aquatic life with long lasting effects |
PubChem ; Merck SDS |
| Paste Form Exemption | Paste form (RPL) is largely exempt from H228 restrictions due to its stable liquid dispersion structure | Document data |
Verified Classification Note: PubChem lists red phosphorus under GHS with H228 (Flammable solid, Danger) and H412 (Harmful to aquatic life with long lasting effects) . Merck's SDS classifies phosphorus (red) as Flam. Sol. 2 (H228) and Aquatic Chronic 3 (H412) . The document's classification as "Warning" rather than "Danger" may reflect the encapsulated product's reduced flammability.
| Parameter | Information |
|---|---|
| Chemical Stability | Stable under recommended storage conditions and below process limit temperatures |
| Conditions to Avoid | Excessive heating above 320°C, open flame, direct friction, and severe mechanical impact |
| Incompatible Materials | Strong oxidizing agents, halogen compounds, humid air streams, and strong alkalis |
| Hazardous Decomposition Products | Under excessive heating or high humidity, uncontrolled decomposition may release spontaneously flammable and toxic Phosphine gas (PH₃) and phosphorus oxide fumes |
| Parameter | Status | Source/Note |
|---|---|---|
| Global Inventory | Listed in TSCA (USA), REACH (EU), and IECSC (China) | Document data |
| REACH Registration | Red phosphorus is actively registered under REACH (EC 918-594-3) by multiple registrants including Clariant | ECHA |
| RoHS/WEEE | Contains no halogen compounds (chlorine, bromine), heavy metals, or restricted phthalates | Document data |
| Water Hazard Class (Germany) | WGK 1 (slightly hazardous to water) | Document data |
| Exposure | Action |
|---|---|
| Inhalation | Move to fresh air immediately; provide oxygen if breathing difficulty; seek medical attention |
| Skin | Remove contaminated clothing; wash with plenty of water and soap for at least 15 minutes; for paste form, wipe mechanically first, then wash |
| Eyes | Hold eyelids open and rinse with plenty of water for at least 15 minutes; consult doctor if irritation persists |
| Ingestion | Rinse mouth with water; never give anything by mouth to unconscious persons; do not induce vomiting; seek emergency medical support |
| Parameter | Information | Source/Note |
|---|---|---|
| Extinguishing Media | Use plenty of water spray or dry sand; CO₂ or gaseous extinguishing agents may be insufficient for elemental phosphorus fires | Document data |
| Special Hazards | Dense white phosphorus pentoxide fumes may be released during fire | Document data; PubChem notes fire may produce irritating/toxic gases |
| Protective Equipment | Firefighters must wear positive-pressure SCBA and full protective chemical clothing | Document data |
Verified Note: PubChem confirms that red phosphorus may be ignited by friction, heat, sparks, or flames and that powders/dusts may explode or burn with explosive violence .
| Parameter | Information |
|---|---|
| Personal Precautions | Use antistatic work clothing, dust mask, and protective goggles; eliminate all spark sources; note slip risk for paste spills |
| Environmental Precautions | Create barriers to prevent entry into sewers, streams, or soil |
| Cleaning | Lightly moisten powder with water spray; collect paste with sand or liquid-absorbent materials; transfer to drums using non-sparking plastic equipment and seal |
| Parameter | Information |
|---|---|
| Handling | Prevent friction, impact, and dust formation; fully ground all transfer systems, feed silos, and extruder lines against static electricity |
| Storage | Powder in 25 kg kraft paper bags; paste in 1250 kg IBC tanks. Store in original packaging in dry, ventilated areas. Paste form must be kept above +5°C minimum to prevent freezing |
| Parameter | Recommendation |
|---|---|
| Engineering Controls | Use local exhaust ventilation hoods and closed feed bunkers to prevent dust accumulation and vaporization |
| Eyes | Dust-tight and splash-resistant safety goggles (EN 166) |
| Skin | Antistatic protective work coveralls and durable nitrile/neoprene long chemical gloves |
| Respiratory | EN 149 approved P3 filter dust mask or combined gas/vapor filter masks in high-concentration environments |
| Parameter | Value | Source/Note |
|---|---|---|
| Acute Oral Toxicity | LD₅₀ (Rat) > 15000 mg/kg (non-toxic profile due to advanced surface treatment) | Document data |
| EPA Assessment | EPA assigned "Low" concern based on oral LD50 values >10,000 mg/kg in rats | EPA |
| Skin/Eye Irritation | Not chemically corrosive or primary irritant; prolonged contact may cause temporary redness due to mechanical friction or rheological components | Document data |
| Carcinogenicity | Not classified as carcinogenic in IARC, NTP, or OSHA lists; EPA estimated "Low" potential for carcinogenicity | EPA |
Critical Toxicity Note: Pure red phosphorus may contain traces of toxic yellow phosphorus (up to 0.6%), and large ingestions may cause adverse systemic effects . The high LD50 (>15000 mg/kg) reported for the encapsulated product reflects the effectiveness of the protective coating in preventing absorption. EPA notes that oral LD50 values as low as 3.03 mg/kg have been reported for some red phosphorus forms, but these may not distinguish between red and white (more toxic) phosphorus .
| Parameter | Value | Source/Note |
|---|---|---|
| Ecotoxicity | Insolubility in water prevents direct acute systemic toxicity to aquatic organisms; uncontrolled environmental release must be prevented | Document data; PubChem classifies as Aquatic Chronic 3 (H412) |
| Persistence and Degradation | High elemental stability in soil; slowly oxidizes to harmless phosphate derivatives over very long periods under atmospheric oxygen and moisture. Release stops when locked into polymer matrix (cured/bound) | Document data |
| Bioaccumulation | No tendency for biological accumulation in living tissues | Document data |
Verified Ecotoxicity Data: Spectrum Chemical SDS reports fish toxicity LC50 values ranging from 0.001-0.037 mg/L for various species (Bluegill, Fathead Minnow, Zebrafish, Rainbow Trout) and Daphnia EC50 of 0.025-0.037 mg/L . These values indicate high aquatic toxicity for unencapsulated red phosphorus, underscoring the importance of encapsulation and proper waste management.
| Parameter | Information |
|---|---|
| Product Disposal | Industrial chemical waste status. Must not be mixed with household waste; dispose of in licensed chemical waste incineration or special disposal facilities |
| Packaging Disposal | Empty kraft paper bags or contaminated 1250 kg IBC tanks must be delivered to licensed recovery companies in accordance with local hazardous waste and packaging regulations |
| Parameter | Information | Source/Note |
|---|---|---|
| ADR/RID (Road) | Powder: UN 1338, AMORPHOUS RED PHOSPHORUS, Class 4.1, Packing Group III (Flammable Solid). Paste (RPL): largely exempt from these solid flammable restrictions due to stable liquid dispersion | Document data; UN 1338 confirmed |
| IMDG (Sea) | Powder: UN 1338, Class 4.1, PG III. Paste: Non-hazardous for maritime transport | Document data |
| IATA (Air) | Powder form subject to quantity restrictions in air transport | Document data |
| Transport Precaution | Secure packaging to prevent puncturing, friction, and wetting during shipping | Document data |
When the polymer matrix is exposed to fire, microencapsulated red phosphorus thermally decomposes to form highly reactive phosphoric and polyphosphoric acid derivatives. These acid components dehydrate polymeric chains, building a thermally stable, non-porous, glassy carbon foam (char) barrier on the surface. This solid-phase barrier cuts off oxygen transfer to the matrix, stops the release of combustible volatile gases, and prevents heat transfer, blocking fire spread.
Verified Mechanism Note: Literature confirms that red phosphorus mainly depends on the condensed phase process including liquid acid (metaphosphoric acid, phosphoric acid, and polyphosphoric acid converted by RP) films covering burning material surfaces, as well as acid-promoted dehydration accelerating the formation of a consolidated char layer .
| Parameter | Status |
|---|---|
| Document Revision No. | 7.0 (2026 Technical Update) |
| Application Principles | The rheological, thermal, and technical specifications presented in this integrated form are based on our standard laboratory test records. Since the final performance of red phosphorus-based systems may vary depending on compound parameters, formulation pH, and the quality of auxiliary synergists used, pilot tests prior to industrial mass production are the user's responsibility. |
Disclaimer: This TDS/SDS is for informational purposes only and is based on available data. Product performance may vary depending on polymer matrix, processing conditions, and formulation. The user is solely responsible for determining the suitability of the product for their specific application and for complying with all applicable local, national, and international regulations. This document is not a substitute for the official SDS provided by the manufacturer.