PIGMENT YELLOW 42/ TRANSPARENT YELLOW 91176
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Technical Information
What Is PY42 / TRANSPARENT YELLOW 91176
PY42 / TRANSPARENT YELLOW 91176, with CAS 51274-00-1 and CI 77492, is a synthetic iron oxide yellow of the goethite structure (FeOOH). It offers outstanding lightfastness and weather resistance, making it far more durable outdoors than organic yellow pigments. Its tinting strength is lower than organic yellows, but this is offset by superior longevity. Synthetic production ensures higher purity than natural ochres. A critical temperature limitation exists: it dehydrates to red Fe2O3 above approximately 180°C, which is essential to consider for plastic processing.
Why Choose TRANSPARENT YELLOW 91176
TRANSPARENT YELLOW 91176 is specifically formulated for high-performance coatings and plastics applications. Its transparent grade provides a unique depth of color and glaze effect while maintaining the excellent durability of iron oxide chemistry. For coatings, it delivers exceptional weather resistance and color stability in exterior applications. In plastics, its heat stability up to 180°C makes it suitable for most processing conditions, though it requires careful temperature monitoring to prevent dehydration and unwanted red shift. This grade excels when a transparent yellow with outdoor durability and chemical resistance is needed, particularly in automotive coatings and outdoor plastic products. There are no sibling grades to compare, making this a distinct product for applications requiring transparency combined with iron oxide robustness.
Key Features
- Transparent yellow iron oxide with goethite crystal structure provides unique optical effects in coatings.
- Exceptional lightfastness and weather resistance ensures long-term outdoor durability without fading.
- Critical thermal stability limit of ~180°C prevents dehydration to red iron oxide during processing.
- Synthetic manufacturing ensures high purity and consistent particle size distribution versus natural ochres.
- Lower tinting strength than organic yellows but superior chemical resistance and UV stability for demanding applications.
C.I.NO.: PY42
Advantage:
Main Application Recommended: Coatings, Plastics
Product Description – PY42
TRANSPARENT YELLOW 91176 (Pigment Yellow 42) features excellent transparency, enabling vivid, clear yellow hues without masking base layers, ideal for coatings and inks. It offers strong light fastness, good chemical resistance, and easy dispersibility, paired with stable tinting power for consistent performance in various applications.
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. | 51274-00-1 | ||
| C. I. Name | Pigment Yellow 42 | EINECS / ELINCS NO. | 257-098-5 | |
| C. I. Constitution No. | 77492 | Chemical Formula | ||
| Technical Performance | ||||
| Full Shade | Tint | |||
| Weather Resistance | 5 | 5 | Heat Stability °C | 200°C |
| Light Fastness | 8 | 8 | ||
| Physical Properties | ||||
| Physical Form | Powder | UV Absorption | ≥ 95% | |
| Specific Density | 1.2 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
What makes PY42 / Transparent Yellow 91176 ideal for transparent coatings and plastics?
PY42, also known as Transparent Yellow 91176 (CAS 51274-00-1, CI 77492), is a synthetic iron oxide prized for its high transparency and unique yellowish hue. Unlike opaque iron oxides, this pigment’s fine particle size allows light to pass through while absorbing specific wavelengths, creating a clean, golden-yellow tint. In coatings, it excels in automotive and industrial finishes requiring depth, such as candy-effect paints or wood stains. For plastics, it disperses well in engineering thermoplastics (e.g., polycarbonate, ABS), offering clarity without haze. Its high color strength means low loadings achieve vivid results, minimizing impact on mechanical properties. This makes it a go-to for applications where transparency and durability are critical.
What are the performance limits of Transparent Yellow 91176 in UV exposure and heat stability?
Transparent Yellow 91176 exhibits excellent heat stability, tolerating processing temperatures up to 280–300°C (536–572°F) for short durations, making it suitable for injection molding and extrusion of plastics like nylon or PBT. However, its UV resistance is moderate versus premium organic yellows; prolonged outdoor exposure may cause slight darkening or loss of transparency due to iron oxide’s photoreactivity. In coatings, it performs well in interior applications unless stabilized with UV absorbers (e.g., benzotriazoles) for exterior use. For plastics, it resists fading in indirect light but is not recommended for long-term, direct-sunlight applications without a protective clear coat or UV stabilizers. Always test under specific end-use conditions.
How does PY42 compare to other CI 77492 yellows, such as opaque yellow iron oxides?
CI 77492 encompasses a range of yellow iron oxides, but PY42 / Transparent Yellow 91176 is distinguished by its particle size and morphology. Standard opaque yellows (e.g., 77492 with larger particles) provide high hiding power and earthy tones, ideal for camouflage or exterior paints. In contrast, PY42 yields a bright, clean color with brilliant transparency, making it unsuitable for high-opacity requirements but perfect for layering effects in coatings (e.g., over aluminum flakes). In plastics, opaque yellows can dull translucency, while PY42 preserves clarity. Cost-wise, PY42 is generally higher due to specialized grinding. Choose PY42 for aesthetic depth; choose opaque 77492 for coverage and cost efficiency.
What processing considerations are critical for Transparent Yellow 91176 in plastic compounding?
Transparent Yellow 91176’s fine particle size (300°C, risking darkening. For polyolefins, add at 0.1–1% by weight to maintain melt flow; at higher loadings (2–5%), melt viscosity may increase slightly. Avoid over-drying hygroscopic carriers (e.g., ABS) as moisture can cause bubbles. Always conduct a rheology trial to balance transparency with processability, and clean equipment promptly to avoid cross-contamination.
How should PY42 be stored, and are there viable alternatives if supply is disrupted?
Store Transparent Yellow 91176 in a cool, dry, well-ventilated area, away from strong oxidizers (e.g., peroxides). Keep containers sealed to prevent moisture absorption, as agglomeration can occur above 60% relative humidity. Shelf life is typically 2–5 years in unopened drums. For substitution, consider Transparent Yellow Iron Oxide (e.g., 77492 variants from other CAS sources) or organic pigments like PY138 (isoindoline) or PY83 (diarylide) for similar transparency, though note organic options offer higher chroma but lower UV stability. Another synthetic iron oxide, PY42 from alternative producers (e.g., Bayferrox 3950), may differ slightly in tone. Always validate color strength, heat stability, and regulatory compliance (e.g., FDA for food contact) before substituting.
TRANSPARENT YELLOW 91176 takeaway: It is a high-transparency synthetic iron oxide ideal for coatings and plastics requiring a golden-yellow tint with depth, offering excellent heat stability up to 300°C but moderate UV resistance—perfect for interior applications or exterior use with proper stabilization, provided you invest in good dispersion practices and consider storage humidity.
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