Description

4,4'-[2,4,8,10-Tetraoxa-3,9-Diphosphaspiro[5.5]Undecane-3,9-Diylbis[Oxy[3-tert-Butyl-4,1-Phenylene]Isopropylidene]]Bis[2-tert-Butylphenol] is a high-performance, sterically hindered organophosphite antioxidant. This compound is critical for preventing oxidative degradation and maintaining the integrity of polymers and other sensitive materials during high-temperature processing and long-term use. It is an essential additive for manufacturers in the plastics, synthetic fiber, and specialty chemical industries seeking to enhance product durability and color stability.

Application

• Polymer Stabilization: Primary antioxidant for polyolefins (PP, PE), polyesters, and engineering plastics to prevent thermal-oxidative degradation during extrusion and molding.
• Synthetic Fiber Production: Protects nylon, PET, and other fibers from molecular weight loss and yellowing during melt spinning and drawing processes.
• Adhesive & Sealant Formulations: Enhances the shelf-life and thermal stability of hot-melt adhesives and polyurethane-based systems.
• Elastomer & Rubber Compounding: Used in SBR, EPDM, and nitrile rubber to retard aging and preserve mechanical properties.
• Lubricant & Fuel Additive: Acts as an antioxidant in synthetic lubricants, greases, and industrial oils to extend service life.
• Specialty Chemical Intermediate: Serves as a key building block for synthesizing more complex phosphite and phosphate stabilizers.

Basic Information

Product Name	4,4'-[2,4,8,10-Tetraoxa-3,9-Diphosphaspiro[5.5]Undecane-3,9-Diylbis[Oxy[3-tert-Butyl-4,1-Phenylene]Isopropylidene]]Bis[2-tert-Butylphenol]
CAS No.	85586-51-2
Molecular Formula	C53H72O8P2
Molecular Weight	899.08 g/mol
Synonyms	Bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite; Pentaerythritol bis(2,4-di-tert-butylphenyl) phosphite; Antioxidant 626; Ultranox 626; ADK STAB PEP-36; Irgafos 126; Doverphos S-9228; 3,9-Bis(2,4-di-tert-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane
EINECS	287-722-0

Quality Control

Our production of 4,4'-[2,4,8,10-Tetraoxa-3,9-Diphosphaspiro[5.5]Undecane-3,9-Diylbis[Oxy[3-tert-Butyl-4,1-Phenylene]Isopropylidene]]Bis[2-tert-Butylphenol] adheres to stringent quality management systems, ensuring batch-to-batch consistency and high purity. The product is manufactured and tested in compliance with ISO 9001 standards. Certificates of Analysis (COA) detailing purity, phosphite content, and key impurity profiles are provided with every shipment to guarantee it meets your specific application requirements.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at a controlled room temperature (15-25°C). Due to its hygroscopic (moisture-sensitive) nature, the container must be kept tightly sealed after initial opening to prevent absorption of atmospheric moisture, which can affect product performance. Keep away from heat sources and incompatible materials.

Specification

Item	Specification
Appearance	White crystalline powder
Identification (IR)	Conforms
Assay (HPLC)	≥ 98.0 %
Melting Point	160 - 175 °C
Phosphite Content	≥ 10.8 %
Acidity (as H3PO4)	≤ 0.05 %
Volatile Matter	≤ 0.5 %
Solution Color (APHA)	≤ 50

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