Description

C.I. Acid Red 129 is a synthetic, water-soluble azo dye belonging to the acid dye class, identified by the CAS registry number 12220-21-2. It is valued for its bright, vivid red hue and good fastness properties on protein-based fibers like wool, silk, and nylon. This dye is essential for manufacturers in the textile, leather, and paper industries seeking consistent, high-quality coloration. Its reliable performance makes it a key component for creating durable and vibrant red shades in various industrial applications.

Application

C.I. Acid Red 129 is a versatile dye with primary applications in industries requiring coloration of proteinaceous and polyamide materials. Its specific uses include:

• Textile Dyeing: Primary application for dyeing wool, silk, and nylon fibers and fabrics.
• Leather Finishing: Used for coloring leather goods, providing rich and even shades.
• Paper Staining: Employed in the production of specialty colored papers and paper products.
• Ink Formulation: A component in the manufacture of certain inks for non-impact printing or specialty markers.
• Biological Staining: Potential use as a histological stain in laboratory settings.
• Polyamide Plastics: Coloring of nylon-based plastics and engineering polymers.

Basic Information

Product Name	C.I. Acid Red 129
CAS No.	12220-21-2
Molecular Formula	C23H21N4NaO6S2
Molecular Weight	528.55 g/mol
Synonyms	Acid Red 129; C.I. 18073; Acid Leather Red G; Nylosan Red F-3GL; Telon Red F3GL; Supranol Red GW; Erionyl Red G; Amido Naphthol Red G; 5-[(2,4-Dimethyl-6-sulfophenyl)azo]-6-hydroxy-1-naphthalenesulfonic acid, disodium salt
EINECS	235-417-1

Quality Control

Our production of C.I. Acid Red 129 adheres to stringent quality management protocols to ensure batch-to-batch consistency and performance. Each lot is analyzed for critical parameters including color strength, shade, solubility, and impurity profile. Certificates of Analysis (COA) documenting purity, physical properties, and conformance to specification are available for every shipment. We are committed to meeting the quality standards required for global industrial applications.

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). Keep away from strong oxidizing agents. The product is light-sensitive (store away from light) and hygroscopic (moisture-sensitive); prolonged exposure to air and humidity should be avoided to maintain stability and performance.

Specification

Item	Specification
Appearance	Red to dark red powder
Identification (IR)	Conforms to standard
Assay (HPLC)	≥ 95.0%
Color Strength	100 ± 3% (vs. Standard)
Moisture Content	≤ 5.0%
Water Solubility	Clear solution at 1%
pH (1% Solution)	6.0 - 8.0
Ash Content	≤ 30.0%

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