Description

3,3'-[Ureylenebis[(1-Hydroxy-3-Sodiosulfonaphthalene-6,2-Diyl)Azo(4,1-Phenylene)Azo]]Bis[4,5-Dihydroxynaphthalene-2,7-Disulfonic Acid Disodium] Salt is a high-purity, complex azo dye intermediate essential for producing vibrant and stable colorants. Its value lies in its ability to form strong covalent bonds with substrates, resulting in excellent lightfastness and washfastness properties for demanding applications. This product is a critical raw material for manufacturers in the textile, leather, paper, and specialty ink industries seeking superior color performance.

Application

• Textile Dyeing: Primary application for dyeing natural and synthetic fibers, particularly where high color strength and durability are required.
• Leather Finishing: Used in the coloration of leather goods, providing rich, penetrating shades with good rub fastness.
• Paper Coloring: Employed in the production of colored papers and paperboards, offering good affinity for cellulose fibers.
• Specialty Inks: A key component in formulating inks for packaging, security printing, and other high-performance marking applications.
• Biological Staining: Potential use as a histological stain in laboratory settings due to its specific chromogenic properties.
• Research & Development: Serves as a sophisticated chemical building block for synthesizing novel dyes and functional materials in R&D laboratories.

Basic Information

Item	Details
Product Name	3,3'-[Ureylenebis[(1-Hydroxy-3-Sodiosulfonaphthalene-6,2-Diyl)Azo(4,1-Phenylene)Azo]]Bis[4,5-Dihydroxynaphthalene-2,7-Disulfonic Acid Disodium] Salt
CAS No.	6428-35-9
Molecular Formula	C58H34N10O26S6Na6 (or related hydrated/salt form)
Molecular Weight	Contact for details
Synonyms	Direct Black 19 (C.I. 35255); C.I. Direct Black 19; Direct Black 19, Disodium Salt; Direct Deep Black EW; Direct Black EW; 3,3'-[1,3-Diazenediylbis[4-[(4-aminophenyl)azo]-6-sulfo-1-naphthalenolato]]bis[4,5-dihydroxy-2,7-naphthalenedisulfonic acid] hexasodium salt; 3,3'-[Carbonylbis(imino-4,1-phenyleneazo-6,2-naphthalenediylazo)]bis[4,5-dihydroxy-2,7-naphthalenedisulfonic acid] hexasodium salt
EINECS	229-208-0

Quality Control

Our production of 3,3'-[Ureylenebis[(1-Hydroxy-3-Sodiosulfonaphthalene-6,2-Diyl)Azo(4,1-Phenylene)Azo]]Bis[4,5-Dihydroxynaphthalene-2,7-Disulfonic Acid Disodium] Salt adheres to a stringent quality management system. Every batch undergoes comprehensive analytical testing, including HPLC for purity and identity confirmation, to ensure consistency and compliance with agreed specifications. Certificates of Analysis (COA) detailing all critical parameters are provided and available upon request.

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). Due to its hygroscopic (moisture-sensitive) nature, the container must be kept tightly sealed after each use to prevent absorption of atmospheric moisture, which can affect product performance and handling.

Specification

Item	Specification
Appearance	Dark blue-black to black powder or granules
Identification (IR)	Conforms to structure
Assay (HPLC)	Min. 90% (Dye Content)
Moisture (Loss on Drying)	Max. 5.0%
Ash Content (Sulfated)	Contact for details
Water Solubility	Freely soluble
pH (1% Solution)	6.0 - 8.0
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.