颜料黄 81（星辉黄 81）

产品概览

Starwin Yellow 81 (Pigment Yellow 81, C.I. 21178, CAS 6842-68-8) is a high-strength disazo pigment that delivers a warm reddish-yellow shade with remarkable opacity and tinting power. Among the disazo yellow family, PY81 stands at the high-opacity, high-strength end of the spectrum — making it the go-to choice when formulators need maximum color impact with minimal pigment loading.

Hangzhou Starwin Tech Co., Ltd. produces PY81 with optimized particle morphology and surface chemistry that promote efficient wetting and dispersion in both solvent-borne and water-borne vehicles, reducing manufacturing cycle times while delivering premium print quality.

密钥标识

Property	价值
C.I. Generic Name	颜料黄 81
客户编号	21178
CAS Registry No.	6842-68-8
化学类别	双偶氮
Visual Appearance	红黄色粉末
Molecular Formula	C₃₄H₃₀Cl₂N₆O₈

Technical Specifications

Parameter	Typical Value
Lightfastness (Full Shade)	4–5（蓝色羊毛色卡）
耐热性	Up to 180 °C
吸油	35–45 克/100 克
堆积密度	0.33–0.48 g/cm³
Particle Size (D50)	0.16–0.26 微米
pH of Aqueous Suspension	5.5–7.5
水溶性	≤ 0.3 %

How to Interpret These Specifications

PY81's 高着色力 means less pigment is needed to achieve target color density compared to lower-strength yellows — directly reducing raw material cost per kilogram of finished ink. The heat resistance of 180 °C在二氮杂黄系列中着色力最高，适用于 PET 瓶胚注塑和尼龙共混等塑料加工工艺。Oil absorption of 35–45 g/100g is relatively low for a high-opacity pigment, allowing formulators to push pigment loading without excessive viscosity increase.

关键应用领域

• High-Opacity Offset Inks: Maximum hiding power enables single-coat coverage on dark or colored substrates.
• Solvent-Based Gravure & Flexo Inks: Exceptional solvent resistance prevents bleeding on plastic films and foil laminates.
• Industrial Enamels & Baking Paints:热稳定性高达 180 °C，可承受卷材涂装和罐体涂装线上的烘烤循环。
• Plastic Masterbatches & Compounds: Suitable for PE, PP, PVC, PET, and nylon systems at processing temperatures up to 180 °C.
• Rubber Coloration: Strong tinting and good dispersion yield uniform color in calendered and molded rubber products.

重要提示

• PY81's reddish-yellow shade is distinctly warmer than PY12 or PY62 — confirm shade match against your target standard before production scale-up.
• For applications requiring full outdoor weatherability exceeding 3 years, consider PY83 or a benzimidazolone yellow for enhanced UV stability.
• 在水性体系中分散时，添加 0.1–0.3% 消泡剂以抵消细分子偶氮颜料轻微的起泡倾向。

Packaging & Storage

Supplied in 25 kg multi-wall paper bags with polyethylene inner liner, or 500 kg / 1000 kg jumbo bags for high-volume consumers. Store in original sealed packaging in a cool, dry, well-ventilated warehouse at 5–35 °C. Avoid exposure to moisture, extreme heat, and direct sunlight. Shelf life: 36 months from date of manufacture under recommended conditions.

FAQ

How does PY81 differ from PY13 in terms of opacity?

Both PY81 and PY13 are high-opacity disazo yellows with reddish undertones. PY81 generally offers slightly higher tinting strength and better thermal stability (180 °C vs. 170 °C), making it preferable for baking finishes and engineering plastics.

Can PY81 be used in food packaging inks?

Standard PY81 is suitable for non-food-contact packaging. For food packaging applications, request our low-aromatic-amines, low-heavy-metal grade that complies with EuPIA exclusion policy and Swiss Ordinance limits.

What is the recommended milling protocol for plastic masterbatch?

For PE/PP carriers, pre-blend pigment with carrier resin and wax dispersant, then process through a twin-screw extruder at 160–180 °C with 300–400 rpm screw speed. Two passes through the extruder typically achieve color uniformity with ΔE < 0.3 against the reference standard.

为何选择我们

Hangzhou Starwin Tech Co., Ltd. manufactures PY81 under ISO 9001 quality management with rigorous batch testing for color consistency (ΔE ≤ 0.5), particle size distribution, and application performance. We provide free samples, full technical documentation, and responsive after-sales support to customers across six continents.

联系我们

Contact our technical sales department for product data sheets, safety data sheets, application trials, or volume pricing. We respond to all inquiries within 24 business hours and offer flexible shipping arrangements from our Hangzhou, China facility.