Description

Irgafos p-Epq CAS NO 119345-01-6 is a high-performance, hydrolytically stable organophosphite antioxidant widely used to protect polymers from thermal degradation during processing and in end-use applications. Its primary value lies in its exceptional ability to prevent molecular weight loss and maintain the physical properties of sensitive polymers, thereby extending product lifespan and enhancing performance reliability. This additive is essential for manufacturers in the plastics, synthetic fiber, and specialty polymer industries who require robust stabilization for high-temperature processing and demanding service conditions.

Application

• Primary antioxidant and process stabilizer for polypropylene (PP) and polyethylene (PE) resins.
• Critical component in stabilization packages for engineering plastics such as polyamides (nylon) and polyesters (PET, PBT).
• Protection of styrenic polymers (e.g., ABS, HIPS) against color formation and chain scission during extrusion and injection molding.
• Stabilization of adhesives and polymer coatings to prevent gelation and maintain viscosity.
• Used in fiber spinning applications to ensure consistent melt viscosity and prevent die buildup.
• Synergistic use with phenolic antioxidants and hindered amine light stabilizers (HALS) in advanced polymer formulations for long-term thermal aging resistance.

Basic Information

Product Name	Irgafos p-Epq
CAS No.	119345-01-6
Molecular Formula	C42H63O3P3
Molecular Weight	685.86 g/mol
Synonyms	Bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite; Pentaerythritol bis(2,4-di-tert-butylphenyl) phosphite; Irgafos PEPQ; PEPQ; Antioxidant PEPQ; Tris(2,4-di-tert-butylphenyl) phosphite (related); Phosphite stabilizer PEPQ; 2,4-Bis(1,1-dimethylethyl)phenyl phosphite (3:1) pentaerythritol cyclic ester
EINECS	Contact for details

Quality Control

Every batch of Irgafos p-Epq is manufactured and tested under a strict quality management system to ensure consistent high purity and performance. Our quality control protocols are designed to meet the exacting standards of the polymer industry, with key parameters including phosphite content, hydrolytic stability, and color. Certificates of Analysis (COA) documenting purity, assay, and specific physical properties are provided with each shipment and are available upon request.

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). This product is hygroscopic (moisture-sensitive); the original container must be kept tightly sealed after opening to minimize exposure to atmospheric moisture, which can affect product performance.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to standard
Assay (HPLC)	≥ 98.0 %
Melting Point	75 - 85 °C
Phosphorus Content	13.0 - 14.0 %
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.