Description

3-Octadecyloxy-9-Phenoxy-2,4,8,10-Tetraoxa-3,9-Diphosphaspiro[5.5]Undecane is a high-performance organophosphorus compound, specifically a spirocyclic phosphite, valued for its exceptional efficacy as a secondary antioxidant and process stabilizer in polymer systems. Its unique molecular structure provides superior resistance to thermal degradation and color formation during high-temperature processing. This product is essential for manufacturers in the plastics, synthetic fiber, and specialty elastomer industries seeking to enhance the longevity and color stability of their materials.

Application

• Polymer Stabilization: Acts as a highly effective secondary antioxidant (phosphite) in polyolefins (PP, PE), polyesters, and engineering plastics to prevent thermal and oxidative degradation during extrusion and molding.
• Color Protection: Minimizes yellowing and maintains color clarity in transparent and pigmented polymer articles subjected to high-temperature processing.
• Synergistic Formulations: Used in combination with primary phenolic antioxidants to create robust stabilization packages that significantly extend polymer service life.
• Fiber Production: Applied as a process stabilizer in the melt spinning of synthetic fibers to prevent viscosity drift and maintain fiber strength.
• Adhesive & Sealant Systems: Enhances the thermal stability of hot-melt adhesives and reactive resin systems.
• Elastomer Processing: Improves the aging resistance of synthetic rubbers during compounding and vulcanization.

Basic Information

Product Name	3-Octadecyloxy-9-Phenoxy-2,4,8,10-Tetraoxa-3,9-Diphosphaspiro[5.5]Undecane
CAS No.	62385-69-7
Molecular Formula	C32H57O6P2
Molecular Weight	614.75 g/mol
Synonyms	Bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite; Pentaerythritol bis(2,4-di-tert-butylphenyl) phosphite; Phosphite stabilizer 626; Antioxidant 626; Ultranox 626; Doverphos S-686; Hostanox PAR 626; Spirocyclic phosphite; 3,9-Bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (related structure)
EINECS	263-464-6

Quality Control

Every batch of our phosphite stabilizer is produced under strict quality management systems and undergoes comprehensive analytical testing to ensure it meets the high-purity standards required for sensitive polymer applications. We provide a detailed Certificate of Analysis (COA) with each shipment, confirming key parameters such as assay, melting point, and solution color. Our production adheres to ISO 9001 guidelines, and the product is compliant with relevant global regulations for polymer additives.

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 product is hygroscopic (moisture-sensitive); keep the original container sealed to prevent absorption of atmospheric moisture, which can affect performance.

Specification

Item	Specification
Appearance	White crystalline powder
Identification (IR)	Conforms to standard
Assay (HPLC)	≥ 98.0 %
Melting Point	185 - 195 °C
Acidity (as H3PO4)	≤ 0.1 %
Volatile Matter	≤ 0.5 %
Solution Color (10% in Toluene)	≤ 50 APHA

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