PIGMENT RED 101/ TRANSPARENT PIGMENT RED 91271
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Technical Information
What Is PY42 / TRANSPARENT PIGMENT RED 91271
CAS 51274-00-1, CI 77492, Type: Iron Oxide (FeOOH). PY42 is a synthetic transparent iron oxide yellow with a goethite crystalline structure, widely used as a durable pigment. It dehydrates to red Fe2O3 above approximately 180°C, a critical temperature limitation for plastics processing. This grade offers excellent lightfastness and weather resistance, making it superior to organic yellows for outdoor applications, while synthetic production ensures higher purity than natural ochres.
Why Choose TRANSPARENT PIGMENT RED 91271
This specific grade is designed for coatings and plastics applications where stability and longevity are paramount. Its transparent nature allows for unique color effects, such as metallic or pearlescent finishes, while maintaining exceptional UV resistance. In plastics, it withstands processing temperatures up to 180°C without degradation, ideal for masterbatches and engineering polymers. For coatings, it provides superior weatherability compared to organic alternatives, resisting chalking and fading even under harsh outdoor conditions. When compared to siblings—none exist for this product—you are selecting a stand-alone, high-purity iron oxide that eliminates batch inconsistency risks. This grade is preferred over natural ochres because synthetic control delivers tighter particle size distribution, ensuring reproducible color strength and transparency across production runs.
Key Features
- Transparent iron oxide with goethite structure provides unique depth and clarity in coatings and plastics.
- Excellent lightfastness and weather resistance ensures long-term color stability in outdoor exposures.
- Dehydration to red Fe2O3 occurs above 180°C, mandating strict temperature control during plastics processing.
- Synthetic production yields higher purity and more consistent particle shape than natural ochre pigments.
- Lower tinting strength than organic yellows is offset by significantly superior durability and fade resistance.
C.I.NO.: PY42
Advantage:
Main Application Recommended: Coatings, Plastics
Product Description –
TRANSPARENT Red 91271 (PIGMENT RED 101) delivers outstanding transparency for rich, non-obscuring hues and excels in light fastness, weather resistance, and easy dispersibility. It’s VOC-free, boasts strong tinting power, and works well with diverse resin systems, ideal for coatings and inks.
Recommended Application
Inks: printing inks
Paints: auto paints, wood paints, architecture paints, powder coatings, industry coatings,
Plastics: Rubber
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 | UV Absorption | ≥ 95% | |
| Specific Density | 1.075 g/cm³ | Solid Content | 97±2% | |
| PH Value | 5-8 | 105°C Moisture | ≤ 3.0% | |
| Fe₂O₃ Content | ≥ 84% | |||
| Residue (45 μm mesh) | ≤ 0.1% | |||
| 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 PY42 / Transparent Pigment Red 91271
What specific applications is this transparent yellow iron oxide best suited for?
PY42 (CAS 51274-00-1, CI 77492) is a synthetic, transparent yellow iron oxide designed for high-clarity coatings and translucent plastics. Its primary fit is in automotive OEM and refinish metallic basecoats, where its transparency allows the underlying aluminum or mica flakes to sparkle while imparting a clean, green-shade yellow. It also excels in wood stains, industrial coatings, and masterbatches for polyolefins and engineering plastics (PC, PET) where UV stability is critical. Unlike opaque yellows, it does not mask the substrate, making it ideal for “color travel” effects and deep, rich tones when combined with other transparent organics. It is not recommended for high-hiding primers or full-hide topcoats where opacity is the main requirement.
What are the key performance limitations in terms of durability and weather resistance?
As an inorganic iron oxide, PY42 offers excellent weatherability and lightfastness, typically achieving a rating of 7-8 on the blue wool scale (DIN 54001) in full-shade formulations. Its primary limitation is chemical sensitivity: it has poor resistance to strong acids and alkalis, which can cause color shift or degradation. In coatings, prolonged exposure to acidic rain or alkaline cleaning agents can cause fading or bronzing. It also has lower tinting strength compared to organic yellows or nano-transparent iron oxides, so higher loadings (often 10-20%) are required for saturated shades. For exterior plastics, stabilize formulations with UV absorbers and hindered amine light stabilizers (HALS) to prevent polymer degradation beyond the pigment’s own stability.
How does PY42 compare to other transparent iron oxide yellows like PY42 (Standard) or nano-yellows?
PY42 (CAS 51274-00-1) is a micro-scale synthetic iron oxide (particle size ~0.1-0.5 µm), offering a balance of transparency and cost. Compared to standard, opaque PY42 yellows (often used in construction), our grade provides superior clarity because particles are smaller and more narrowly distributed, reducing light scattering. However, it is less transparent than nano-scale iron oxides (e.g., 30-50 nm), which offer extreme transparency and stronger color strength but are significantly more expensive and may require specialized dispersion. In terms of color, our PY42 gives a pure green-shade yellow, while nano variants often shift slightly towards orange. For most industrial coatings and general plastic masterbatch, our PY42 delivers the best cost-performance ratio for transparency without the handling challenges of nanoparticles.
What processing precautions are needed for dispersing PY42 in plastics or coatings?
PY42 is moderately easy to disperse but requires high shear to break down agglomerates and avoid streaking in transparent applications. In plastics, use a twin-screw extruder or Banbury mixer at 180-220°C; avoid excessive temperatures above 250°C to prevent iron oxide conversion (which can darken the shade). Pre-dispersion in a carrier wax or solvent-borne millbase (using bead mills or three-roll mills) is recommended for coatings. Because it is hygroscopic, ensure the pigment is stored dry (< 0.5% moisture) before processing, as moisture can cause fisheyes in solvent systems or splay marks in injection-molded plastics. For waterborne systems, verify pH compatibility—PY42 is stable at pH 4-9, but extreme acidity or alkalinity can trigger coagulation.
What is the recommended storage stability and are there viable substitutes if supply changes?
When stored in a cool, dry environment (< 40°C, < 60% RH) in sealed containers, PY42 has a shelf life of at least 24 months without deterioration in color or dispersibility. It does not react with air or light, unlike many organic pigments. Iron oxide is non-flammable and non-explosive, simplifying warehouse compliance. For substitution, if Transparent Pigment Red 91271 becomes unavailable, candidates include PY42 grades from other CI 77492 sources (check particle size distribution), Pigment Yellow 119 (zinc ferrite—slightly more opaque) or Pigment Brown 6/7 (mixed iron oxides—less green). Organic yellows like PY83 or PY154 can mimic the color but lack UV stability. Always test compatibility: substitution often requires adjusting dispersion parameters due to differing hardness and surface treatment.
TRANSPARENT PIGMENT RED 91271 is a high-performance synthetic yellow iron oxide (PY42) offering exceptional transparency, weather resistance, and processability for premium coatings and plastics, delivering brilliant color effects where clarity and durability are paramount without the premium cost of nano-pigments.
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