Description

C.I. Acid Black 128 is a high-performance, synthetic acid dye belonging to the azo chemical class, identified by CAS No. 37293-45-1. This dye is valued for its excellent color fastness, deep black shade, and strong affinity for protein-based fibers like wool, silk, and nylon. It is a critical component for manufacturers in the textile, leather, and paper industries seeking durable and vibrant coloration for their products.

Application

• Textile Dyeing: Primary application for dyeing wool, silk, and nylon fibers to achieve deep, fast black shades.
• Leather Finishing: Used in the dyeing of leather goods, providing rich color and good penetration.
• Paper Coloration: Employed for specialty paper products requiring a stable black colorant.
• Ink Formulation: A component in the manufacture of certain inks for industrial or specialty printing.
• Biomaterial Staining: Potential use in laboratory settings for staining protein-based biological materials.

Basic Information

Product Name	C.I. Acid Black 128
CAS No.	37293-45-1
Molecular Formula	C40H23N7Na4O13S4
Molecular Weight	1083.86 g/mol
Synonyms	Acid Black 128; C.I. 26300; Acid Leather Black BR; Acid Black BR; Nylosan Black N-BL; Telon Black BGL; Supranol Fast Black B; Acid Fast Black B; Black 128 (Acid Dye)
EINECS	253-441-5

Quality Control

Our C.I. Acid Black 128 is manufactured under a stringent quality management system. Each batch is tested to ensure consistent strength, shade, and purity, meeting the specifications required for industrial dyeing applications. A Certificate of Analysis (COA) detailing parameters such as color strength, solubility, and impurity content is provided with every shipment to guarantee reliable performance and batch-to-batch consistency.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). This product is hygroscopic (moisture-sensitive); ensure the container is kept tightly sealed to prevent absorption of atmospheric moisture, which can affect performance.

Specification

Item	Specification
Appearance	Black powder or granules
Identification (IR)	Conforms to standard
Color Strength	100 ± 3% (vs. Standard)
Moisture Content	≤ 5.0%
Water Insoluble Matter	≤ 1.0%
Shade	Conforms to standard
Solubility in Water	Conforms

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.