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Weathering Pioneer: The Role of Dibasic Lead Phosphite in PVC Processing

Product Overview

Lead Dibasic Phosphite (LDSP) is a highly effective PVC stabilizer widely used in rigid and flexible PVC formulations that require strong thermal stability, weather resistance, and electrical insulation properties.

Chemically identified as 2PbO·PbHPO₃·H₂O (CAS No. 12141-20-7), this compound appears as a white or slightly yellow fine powder. It is insoluble in water and most organic solvents, but slightly soluble in mineral acids such as hydrochloric acid and nitric acid.

Lead Dibasic Phosphite is known for its ability to protect PVC materials from heat degradation and UV exposure, making it particularly suitable for products used in outdoor and high-temperature processing environments.

Key functional benefits include:

  • Excellent weather resistance and UV shielding, helping extend the service life of outdoor PVC products
  • High thermal stabilization performance, ensuring stable processing at elevated temperatures
  • Antioxidant protection, reducing polymer degradation during manufacturing
  • Strong electrical insulation properties, making it suitable for cable and electrical applications

Key Specifications

Typical quality parameters include:

  • Chemical Composition: Lead Dibasic Phosphite
  • Molecular Formula: 2PbO·PbHPO₃·H₂O
  • CAS Number: 12141-20-7

Physical and Chemical Properties

  • Appearance: White or slightly yellow fine powder
  • Lead Content (PbO): 88 ± 2%
  • Moisture Content: ≤ 0.5%
  • Particle Size: 99% passing through 325 mesh sieve (~44 μm)
  • Density: Approximately 6.1 g/cm³
  • Thermal Stability: Suitable for processing temperatures of 180–200°C
  • Solubility: Insoluble in water, slightly soluble in acids

These characteristics make LDSP highly effective for high-temperature PVC processing applications.


Main Application Areas

Lead Dibasic Phosphite is commonly used as a primary or auxiliary stabilizer in PVC formulations, particularly where durability and weather resistance are required.

Rigid PVC Products

Widely used in:

  • PVC pipes and fittings
  • Window and door profiles
  • PVC sheets and panels

These applications benefit from improved thermal stability, UV resistance, and long-term durability.


Flexible PVC Products

Used in applications such as:

  • Cable insulation layers
  • Wire sheathing materials
  • Flexible industrial PVC components

The stabilizer enhances electrical insulation performance and resistance to thermal aging.


PVC Films and Sheets

Applied in:

  • Packaging films
  • Agricultural films
  • Protective PVC sheets

It improves UV resistance and processing stability, ensuring longer product life.


Other Polymer Applications

Lead Dibasic Phosphite can also function as an auxiliary stabilizer in certain polymer formulations, improving overall processing performance and thermal resistance.


Packaging and Storage

Packaging

Standard packaging options include:

  • 25 kg moisture-proof composite paper bags
  • Plastic woven bags lined with PE film

For bulk orders, ton bags or customized packaging solutions can be provided.


Storage Conditions

To maintain product quality:

  • Store in a cool, dry, and well-ventilated warehouse
  • Keep away from heat sources and open flames
  • Avoid contact with acidic substances to prevent chemical reactions

Recommended storage parameters:

  • Temperature: below 30°C
  • Relative humidity: below 70%

Shelf Life

Under recommended storage conditions, the product typically has a shelf life of up to 2 years in unopened original packaging.

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