Liaoning Xinda Talc Group Co., Ltd. - Yang Yongli
Introduction
Talc powder PP (polypropylene) resin masterbatch is a concentrated particle made by mixing PP resin and talc powder with various additives. In plastic processing experiments, Xinda Talc R&D Center used stearic acid, zinc stearate, and calcium stearate as commonly used additives in the synthesis of talc powder and PP resin masterbatch to simplify the production process and improve the efficiency of talc powder addition in PP resin. This report will elaborate on the specific roles of the three additives.
1、 The role of stearic acid in the synthesis of talc powder and PP resin masterbatch
1. Lubrication effect: stearic acid is an excellent internal lubricant that can reduce friction between PP resin molecular chains, lower melt viscosity, improve resin flowability, make masterbatch easier to form during processing, and thus reduce equipment energy consumption.
2. Dispersion auxiliary effect: During the synthesis of talc powder masterbatch, stearic acid can assist other solid additives to disperse in PP resin, prevent additive aggregation, and improve the uniformity of talc powder masterbatch components.
3. Demoulding effect: stearic acid can form a lubricating film on the surface of resin and processing equipment (such as screws), reducing the adhesion between resin and equipment, making it easier for the formed masterbatch to detach from the equipment, and reducing production failures.
2、 The role of zinc stearate in the synthesis of talc powder PP resin masterbatch
1. Stabilization effect: Zinc stearate is a heat stabilizer that can inhibit the thermal degradation of PP resin during high-temperature processing, reduce the breakage of resin molecular chains caused by high temperature, protect the molecular structure of PP resin, and maintain the mechanical properties of talc powder masterbatch.
2. Lubrication and demolding function: It has both internal and external lubrication properties, which can improve the flowability of resin melt, enhance the lubrication effect between the masterbatch and the equipment surface, and improve demolding efficiency, especially suitable for the processing of high filling talc powder PP masterbatch.
3. Dispersion promoting effect: The polar groups of zinc stearate can bind to the surface of talc powder, reducing the attraction between talc powders, promoting their uniform dispersion in PP resin, and improving the comprehensive performance of talc powder masterbatch.
3、 The role of calcium stearate in the synthesis of talc powder PP resin masterbatch
1. Thermal stability and antioxidant auxiliary effects: Calcium stearate can absorb trace acidic substances (such as hydrogen chloride produced during degradation) generated during PP resin processing, avoiding further degradation of the resin caused by acidic substances. When used in combination with other stabilizers, it can enhance the thermal stability and antioxidant properties of the masterbatch.
2. Lubrication and processing improvement effect: As a lubricant, calcium stearate can reduce the viscosity of PP melt, improve processing flowability, reduce equipment wear, and extend the service life of processing equipment.
3. Enhance filling compatibility: For PP masterbatch containing inorganic fillers, calcium stearate can modify the surface of the filler to improve its compatibility with PP resin and reduce the performance degradation of the masterbatch caused by poor interface bonding between the filler and resin.
Summary
Xinda Talc Research and Development Center found in experiments that stearic acid, zinc stearate, and calcium stearate all have lubrication, dispersion, or stabilization effects as the core in the synthesis of talc powder PP resin masterbatch, but each has its own focus: stearic acid mainly focuses on basic lubrication and dispersion assistance; Zinc stearate highlights thermal stability and efficient demolding; Calcium stearate performs better in terms of acid resistance and filling compatibility. The three are often used in conjunction with the specific formula and processing requirements of the masterbatch to improve the processing performance of PP resin talc powder masterbatch.
