PIGMENT BLACK 11/ IRON OXIDE BLACK 303T
:
Technical Information
What Is PBk11 / IRON OXIDE BLACK 303T
PBk11 / IRON OXIDE BLACK 303T (CAS 1317-61-9, CI 77499) is a synthetic iron oxide pigment of the Fe₃O₄ magnetite type. It delivers the highest tinting strength of all iron oxide black pigments and naturally absorbs light for deep, neutral black shades. The pigment exhibits strong magnetic properties, making it suitable for specialized applications. Manufactured via the Laux process or precipitation, it boasts excellent lightfastness and chemical resistance, ensuring long-lasting performance in demanding environments.
Why Choose IRON OXIDE BLACK 303T
This specific grade, 303T, is optimized for coatings and plastics, offering superior dispersion and consistent jetness compared to standard iron oxide blacks. Its high tinting strength allows for lower dosage rates, reducing material costs while maintaining intense color. For coatings, 303T provides excellent hiding power and resistance to weathering, UV exposure, and chemical attack, making it ideal for industrial and architectural paints. In plastics, it withstands high processing temperatures without degrading, ensuring uniform coloration in masterbatches, films, and molded parts. Unlike sibling grades that may prioritize magnetic recording or toner properties, 303T is engineered exclusively for color consistency and processability in coatings and plastics, eliminating the need for multiple formulations across these applications.
Key Features
- Delivers the highest tinting strength among all iron oxide black pigments for maximum color yield.
- Offers superior lightfastness and chemical resistance for durable performance in outdoor and harsh environments.
- Provides excellent dispersion in both solvent-borne and waterborne coating systems for streak-free finishes.
- Maintains thermal stability during plastic processing, preventing color shift or degradation at high temperatures.
- Exhibits strong hiding power and opacity, enabling full coverage with minimal pigment loading.
C.I.NO.:PBk11
Advantage:
Main Application Recommended: Coatings, Plastics
Product Description –
IRON OXIDE BLACK 303T (Pigment Black 11) is a inorganic pigment with strong tinting strength, excellent hiding power, and great color/UV/heat/water resistance for long-lasting use. It also has good dispersibility, is non-toxic and eco-friendly, ideal for paints, plastics and construction materials.
Recommended Application
Coatings: Industrial paints
Plastics: PE, PP, PC, PBT, PVC, PU, POM, PS, PET, EVA, ABS
Technical Data
| Product Information | ||||
| Chemical Type | CAS NO. | 1317-61-9 | ||
| C. I. Name | Pigment Black 11 | EINECS / ELINCS NO. | 215-227-5 | |
| C. I. Constitution No. | 77499 | Chemical Formula | ||
| Technical Performance | ||||
| Full Shade | Tint | |||
| Weather Resistance | 5 | 5 | ||
| Light Fastness | 7 | 7 | ||
| Physical Properties | ||||
| Physical Form | Powder | PH Value: | 5.0 ~ 8.0 | |
| Content % | 70 ± 5 | Sieve Residue (45 um %) | Max 0.3 | |
| Strength | 95-105 | Oil Absorption(ml/100g): | 25 | |
| Moiscture % | Max 1.50 | Temperature Reistance | 500℃ | |
| Water Soluble % | Max 1.0 | |||
| Packaging | ||||
| 25kgs/bag 1000kgs/Pallet | ||||
| Storage | Shelf Life | 5 years | ||
| Should be stored in cool, dry and ventilate place. | ||||
| TRANSPORTATION | ||||
| Avoid inversion, sunlight, moisture and crash. Avoid damage the package. | ||||
- Light fastness: Light fastness rating is assessed on 1 to 8 Blue Wool scale where 1 = ‘Poor’ and 8 = ‘Excellent’.
- Heat Stability : Heat stability values given indicate the maximum temperature at which the pigment can be stoved for 10 min. on the full shade and in reductions without undergoing any significant change in shade.
- Oil absorption: The oil absorption is determined on the basis of EN ISO 787-5 and given in g linseed oil per 100 gm. pigment.
- Solvent bleeding: The bleeding in solvents is tested using the powder grades and the visual rating given on 1 to 5 Grey scale
where 1 = ‘Heavy bleeding’ and 5 = ‘No bleeding”
Technical Note — The data and recommendations provided are based on HONOR Pigment’s internal testing and manufacturing experience. They are offered in good faith to assist customers in evaluating product suitability for their specific applications. As processing conditions, formulations, and end-use requirements vary widely, customers should conduct their own validation under actual use conditions. HONOR Pigment makes no warranties, express or implied, regarding the accuracy of this information or its fitness for any particular purpose. Nothing herein shall be construed as a license or recommendation to infringe any patent. HONOR Pigment’s standard terms and conditions of sale apply.oduct contains particles < 0.1 μm. Any user of this product is responsible for determining the suitability of Honor Pigments’s products for its particular application & to ensure that any proprietary rights & existing laws & legislation are observed.
Why Choose Honor Pigments?
- 🌍 Global Export Expertise — Trusted by customers in 40+ countries for consistent quality and reliable supply
- ✅ Strict Quality Control — ISO 9001 certified with batch-to-batch consistency and zero-defect policy
- 💰 OEM Production Advantage — Competitive pricing without compromising pigment performance
- 🧪 Technical Support — Free color matching, formulation advice and sample testing before bulk order
Frequently Asked Questions About PBk11
Is PBk11 / Iron Oxide Black 303T suitable for both coatings and plastics applications?
Yes, PBk11 (CI 77499) is a high-purity synthetic iron oxide black pigment designed for dual use in coatings and plastics. In solvent-based and waterborne coatings, it provides deep, jet-black shades with excellent opacity and weatherability. For plastics (polyolefins, PVC, ABS), it offers good dispersion and heat stability up to 200°C (392°F) during processing. However, for high-temperature engineering plastics (e.g., polycarbonate, nylon) exceeding 250°C, we recommend pre-testing, as iron oxide can catalyze polymer degradation at extreme temperatures. Always verify compatibility with your specific resin system and processing conditions.
What are the key performance limitations of Iron Oxide Black 303T?
The primary limitation is heat stability: PBk11 begins to degrade above 200-250°C, losing color depth and shifting to reddish-brown due to oxidation (Fe₃O₄ → Fe₂O₃). This makes it unsuitable for high-temperature injection molding or powder coatings cured above 200°C. Additionally, its tinting strength is lower than carbon black (PBk7), requiring higher loadings (3-8% vs. 1-2%) for full opacity. It also has limited chemical resistance to strong acids and alkalis, which may cause fading or leaching. For exterior coatings, ensure proper binder selection to prevent chalking from UV exposure.
How does PBk11 compare to other iron oxide blacks like PBk11-303 or carbon black (PBk7)?
Compared to standard PBk11 (e.g., grade 303), the 303T variant typically features narrower particle size distribution (0.2-0.5 µm) and surface treatment for enhanced dispersion in plastics and coatings, reducing mill base agglomeration. Versus carbon black (PBk7), PBk11 offers better transparency, warmer undertones (slightly brownish), and superior UV stability–it does not block UV light but instead reflects it, making it ideal for coil coatings and outdoor applications. However, PBk7 provides stronger blackness, higher conductivity, and better cost efficiency for high-volume industrial paints where opacity is paramount.
What processing considerations are critical when compounding PBk11 into plastics?
Optimal dispersion requires high-shear mixing (twin-screw extruder or Banbury mixer) with appropriate dispersing agents (e.g., stearates or waxes) to break primary aggregates. Avoid excessive shear or prolonged dwell times above 200°C, as this can cause thermal degradation and color shift. For masterbatch production, we recommend a letdown ratio of 1:10 to 1:20 (pigment to carrier resin). Pre-drying the pigment (2-4 hours at 80°C) prevents moisture-induced surface defects like splay marks. For coating formulations, ball milling or bead milling for 30-60 minutes achieves Hegmann gauge fineness < 10 µm.
What is the recommended storage and substitution protocol for Iron Oxide Black 303T?
Store in a cool, dry environment (below 40°C, relative humidity <60%) away from direct sunlight and oxidizing agents. In sealed containers, shelf life is 24 months; once opened, use within 6 months to avoid moisture absorption and caking. For substitutions, compatible alternatives include uncoated PBk11 (for reduced cost in low-performance systems) or PBk7 carbon black where extreme blackness or heat resistance (up to 300°C) is required. However, note that carbon black lacks the UV stability and chemical inertness of iron oxide. Always conduct side-by-side tinting and weathering tests before full replacement.
**IRON OXIDE BLACK 303T takeaway:** This versatile, weather-resistant pigment excels in moderate-temperature coatings and general-purpose plastics, offering consistent deep black shades and easy processing–ideal for applications where carbon black’s UV instability or high-temperature needs are not a factor.
📩 Need more details?
Request TDS, SDS, or a free sample for testing.