Description

Leuco Sulfur Black 18 is a high-performance, water-soluble dye intermediate, specifically the reduced form of Sulfur Black 1. This compound is essential for achieving deep, economical black shades with excellent fastness properties on cellulosic fibers. It is a critical raw material for dye manufacturers and textile processors serving the global denim, cotton, and viscose markets. Consistent quality and reliable supply are paramount for maintaining color uniformity and production efficiency in downstream applications.

Application

• Primary Use in Textile Dyeing: As the key intermediate for the on-site oxidation and fixation of Sulfur Black dyes on cotton, linen, viscose, and other cellulosic fabrics.
• Denim Production: Widely used for dyeing yarns and fabrics to produce classic indigo and black denim with superior wash-down effects.
• Garment Dyeing: Employed in exhaust and continuous dyeing processes for ready-made garments to achieve deep black shades.
• Paper Coloring: Used in the tinting of specialty papers where a deep, cost-effective black color is required.
• Leather Finishing: Application in dyeing leather goods, providing good penetration and color depth.
• Ink Formulation: Serves as a colorant component in the manufacture of certain industrial inks.

Basic Information

Product Name	Leuco Sulfur Black 18
CAS No.	114680-26-1
Molecular Formula	C22H16N6Na4O19S8
Molecular Weight	1084.96 g/mol
Synonyms	Sulfur Black 1, Leuco Form; C.I. Sulfur Black 1, Reduced; C.I. 53185; Immedial Black VSG; Kayaku Sulphur Black B; Sulphur Black B; D&C Black No. 1; Leuco Sulphur Black T; Hydrosulphur Black; Sodium 4-[[4-[(2,5-diamino-7-sulfonato-1-naphthyl)diazenyl]-7-sulfonato-1-naphthyl]diazenyl]-5-hydroxy-6-(phenylamino)naphthalene-2,7-disulfonate (reduced form)
EINECS	Contact for details

Quality Control

Our Leuco Sulfur Black 18 is manufactured under a strict quality management system. Every batch is tested to ensure it meets precise specifications for strength, solubility, and impurity profiles critical for consistent dyeing performance. We provide comprehensive Certificates of Analysis (COA) with key parameters including assay, moisture content, and solubility. Our quality commitment supports your need for reliable batch-to-batch consistency and compliance with industry standards.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). This product is hygroscopic (moisture-sensitive); ensure containers are sealed after each use to prevent absorption of atmospheric moisture, which can affect performance. Keep away from strong oxidizing agents.

Specification

Item	Specification
Appearance	Dark gray to black powder or granules
Identification (IR)	Conforms to standard
Assay (Titration)	Min. 95%
Moisture Content	Max. 5.0%
Water Solubility	Completely soluble
pH (1% Solution)	8.0 - 10.0
Iron Content	Max. 50 ppm
Heavy Metals (as Pb)	Max. 20 ppm

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