Description

2-Naphthol-5,7-Disulfonic Acid is a key sulfonated naphthalene derivative used as a versatile intermediate in the synthesis of dyes and pigments. Its disulfonic acid groups provide excellent water solubility and reactivity, making it crucial for creating vivid and stable colorants. This compound is essential for manufacturers in the dye, textile, and specialty chemical industries seeking to produce high-performance azo dyes and other functional color molecules.

Application

• Primary intermediate for the synthesis of azo dyes and pigments, particularly acid dyes for wool, silk, and nylon.
• Key building block in the production of reactive dyes used in textile printing and dyeing.
• Used in the manufacture of food colorants (where specified grades are compliant).
• Intermediate for lake pigments used in inks, plastics, and coatings.
• Starting material for optical brightening agents (fluorescent whitening agents).
• Precursor in organic synthesis for pharmaceutical intermediates and specialty chemicals.
• Used in research and development for novel functional dyes and chemical sensors.

Basic Information

Product Name	2-Naphthol-5,7-Disulfonic Acid
CAS No.	575-05-3
Molecular Formula	C₁₀H₈O₇S₂
Molecular Weight	304.30 g/mol
Synonyms	5,7-Dihydroxy-1,3-naphthalenedisulfonic Acid; 5,7-Dihydroxynaphthalene-1,3-disulfonic Acid; 1,3-Naphthalenedisulfonic Acid, 5,7-dihydroxy-; 2-Hydroxynaphthalene-5,7-disulfonic Acid; NSC 40326; Naphthol Disulfonic Acid; 2-Naphthol-5,7-disulfonic Acid Monosodium Salt (common salt form)
EINECS	209-379-7

Quality Control

Our 2-Naphthol-5,7-Disulfonic Acid is produced under a stringent quality management system. Each batch undergoes rigorous analytical testing to ensure consistent purity, identity, and performance as a dye intermediate. Certificates of Analysis (COA) detailing specific batch results are provided and available upon request to support your quality assurance and regulatory compliance needs.

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 material is hygroscopic (moisture-sensitive); keep the container tightly sealed to prevent absorption of atmospheric moisture, which can affect quality and handling properties.

Specification

Item	Specification
Appearance	Off-white to light tan crystalline powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Loss on Drying	≤ 2.0%
Sulfated Ash	≤ 0.5%
Heavy Metals (as Pb)	≤ 20 ppm
Related Substances (HPLC)	Individual impurity ≤ 1.0%

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