PIGMENT RED 101/ IRON OXIDE RED 190
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Technical Information
What Is PR101 / IRON OXIDE RED 190
PR101 / IRON OXIDE RED 190 (CAS 1309-37-1, CI 77491) is an inorganic iron oxide (Fe2O3) pigment with a hematite crystal structure. It offers excellent lightfastness and weather resistance, rated 5 out of 5. Completely insoluble and chemically inert, this pigment provides a wide shade range from yellowish-red to bluish-red, controlled by particle size and calcination temperature. Produced via calcination of yellow iron oxide, the Laux process, or copperas red decomposition, it is a workhorse red pigment used for centuries in construction, coatings, plastics, and ceramics.
Why Choose IRON OXIDE RED 190
IRON OXIDE RED 190 is specifically optimized for coatings and plastics applications, delivering superior color consistency and dispersion in these media. Its controlled particle size ensures a clean, bluish-red shade with high tinting strength, making it ideal for industrial paints, automotive coatings, and plastic masterbatches. Unlike sibling grades that may vary in shade or be tailored for construction or ceramics, this grade provides the precise balance of opacity and brightness required for high-performance surface finishes. When processing, it offers excellent flow properties and minimal dusting, reducing handling issues in production. Its chemical inertness ensures stability in acidic or alkaline binder systems, outperforming organic reds in UV resistance and longevity. With centuries of proven use, it remains the go-to choice for manufacturers demanding reliable, fade-proof red color.
Key Features
- Provides maximum UV stability and weather resistance (5/5 rating) for long-term outdoor durability in coatings.
- Offers high thermal stability without color shift during plastics processing at elevated temperatures.
- Exhibits complete insolubility in water, solvents, and organic media, ensuring no bleeding or migration.
- Delivers consistent batch-to-batch particle size distribution for reliable color matching in production.
- Maintains chemical inertness against acids, alkalis, and environmental pollutants in aggressive application environments.
C.I.NO.: PR101
Advantage:
Main Application Recommended: Coatings, Plastics
Product Description – PR101
IRON OXIDE RED 190 (PIGMENT RED 101) delivers excellent light and weather fastness, ensuring long-term color stability in outdoor or exposed applications. It also has good chemical resistance and cost-effectiveness, making it a reliable choice for coatings, construction materials, and plastics.
Recommended Application
wall bricks, cements, paving bricks, paintings, coatings, plastics, rubber and so on
Technical Data
| Product Information | ||||
| Chemical Type | CAS NO. | 1309-37-1 | ||
| C. I. Name | Pigment Red 101 | EINECS / ELINCS NO. | 215-168-2 | |
| C. I. Constitution No. | 77491 | Chemical Formula | ||
| Technical Performance | ||||
| Full Shade | Tint | |||
| Weather Resistance | 5 | 5 | ||
| Light Fastness | 8 | 8 | ||
| Physical Properties | ||||
| Physical Form | Powder | Moisture： | ≤1.0% | |
| Content（Fe2O3 •αH2O）： | ≥96.0% | PH Value: | 3-7 | |
| Oil Absorption: | 15-25 ml/100g | Density： | 0.7-1.0g/cm3 | |
| Residue on Sieve(90 sieve)： | ≤0.3% | particle shape： | Spherical | |
| Water soluble content： | ≤0.3% | Color strength: | 95%~105% | |
| Chromatic aberration △E: | ≤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 PR101
What coatings and plastics applications is IRON OXIDE RED 190 best suited for?
IRON OXIDE RED 190 (PR101) is a high-performance synthetic iron oxide designed for industrial coatings, architectural paints, and engineering plastics. In solvent-borne and water-borne coatings, its excellent hiding power and chemical resistance make it ideal for primers, anti-corrosion systems, and exterior finishes. For plastics, it performs well in polyethylene, polypropylene, and PVC, offering heat stability up to 200°C. It is widely used in construction materials like concrete stains and roofing granules. However, for extremely high-temperature applications (above 300°C), or for food-contact packaging, confirm regulatory compliance first. Always test compatibility with your specific resin system, especially if using in clear coats where gloss retention is critical.
What are the key performance limits of PR101 regarding weatherability and chemical resistance?
IRON OXIDE RED 190 exhibits outstanding UV stability and lightfastness, maintaining color for decades in exterior applications—far exceeding organic red pigments. However, its opacity is slightly lower than carbon black, requiring 10–15% higher loading for full coverage in dark shades. Chemically, it resists weak acids and alkalis but degrades in concentrated hydrochloric or sulfuric acids. In plastics, processing temperatures above 220°C may cause slight darkening (shift to a deep maroon). For direct food contact or potable water systems, verify local regulations, as some iron oxide grades have migration limits. Always perform accelerated weathering tests if the product will face coastal or acidic rain environments.
How does IRON OXIDE RED 190 compare to PR102 (yellow iron oxide) or PR101 black?
While all are synthetic iron oxides, PR101 RED 190 is distinctly more opaque and has a warmer, lemony-red hue compared to PR102 (yellow iron oxide), which is more transparent and used for buff or tan tints. PR101 black (magnetite) offers superior magnetic properties and lower tinting strength. Unlike PR102, RED 190 has higher thermal stability and is preferred for plastics that require processing above 180°C. However, PR102 is better for achieving pale pastels. For cost-sensitive applications, natural red oxides (e.g., hematite) are cheaper but contain impurities that reduce color consistency and UV resistance. Always balance cost against the need for batch-to-batch color uniformity, especially in extruded plastic profiles.
What processing precautions are necessary when adding PR101 to plastics or coatings?
For plastics, pre-drying PR101 is not mandatory unless stored in high humidity—exposure to moisture can cause agglomeration during extrusion. Use a high-shear mixing step (e.g., double-screw extruder) to fully disperse the pigment, as poor dispersion leads to streaking. In coatings, avoid over-grinding beyond 15 microns, as excessive grinding reduces particle size and may lower opacity. For solvent-based systems, wetting agents like lecithin or polymeric dispersants improve dispersion. Never use PR101 in highly acidic or oxidizing resin formulations (e.g., epoxy with strong acid catalysts) without prior consultation. Always wear a respirator and gloves when handling the powder; while not classified as toxic, inhalation of fine dust irritates mucous membranes.
What are the recommended storage conditions and viable substitution options for this pigment?
Store PR101 in a cool, dry area (below 40°C) away from strong oxidizers. Shelf life is effectively indefinite if sealed—it does not expire chemically. However, opened bags may absorb moisture over time, causing slight clumping; break up clumps with a sieve before use. For substitution, other iron oxide reds (e.g., PR101 180 or PR101 200) have slight hue differences: 190 is a medium shade red, while 180 is bluish-red and 200 is yellower. Synthetic PR101 outperforms natural red iron oxide in color consistency and purity. In an urgent pinch, PR101 can be replaced with a mixture of PR101 black and PR102 yellow to approximate the shade, but tinting strength and gloss will vary. Always requalify a substitute in your specific formulation.
IRON OXIDE RED 190 takeaway: This versatile, weather-resistant pigment delivers reliable color stability for coatings and plastics, but requires proper dispersion and thermal management to unlock its full opacity and durability.
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