What is the working principle of permanent anti-static masterbatch?

The biaxially oriented polypropylene (BOPP) film with permanent anti-static masterbatch mechanism is a crystalline product obtained by adding appropriate functional additives to polypropylene proprietary materials and undergoing biaxially oriented stretching process.
Due to polypropylene being a typical non-polar polymer material with extremely poor water absorption, the surface charges generated by friction are difficult to dissipate, resulting in strong electrostatic properties. To eliminate the charges generated on the membrane surface, anti-static agents need to be added. Antistatic masterbatch is a bipolar substance that can migrate to the surface of thin films, absorb moisture from the air, form a conductive layer, and promptly dissipate accumulated charges, giving it the ability to control charging. The ability to disperse charges is essential for the processing and use of polypropylene films. Otherwise, during the production process, static electricity may cause electric shock to the operators; When making bags or packaging goods, surface charges can cause the film to adhere to the packaging equipment; For packaged goods, due to static electricity, dust will be adsorbed during storage or sales, affecting the image of the product.
Usually, the ability of permanent anti-static masterbatch to eliminate static electricity is measured by the time it takes for the charge accumulated on the surface of BOPP film to decay to half its value, which is the electrostatic half-life value.
Antistatic agents have mobility, and after being added to polymers, they will migrate from the added layer to the layer with low content or not added. Therefore, in the actual production process, it is generally only added to the core material of the film. Otherwise, if an anti-static agent is added to the surface layer, it will be consumed due to reverse migration to the core layer and will not have the anti-static effect.
The migration ability of permanent anti-static masterbatch added to the anti-static agent in the core layer is affected by storage temperature and storage time. Within the allowable range, the higher the temperature, the faster the migration speed. At the same temperature, migration requires a process and generally requires storage for one to two weeks. In addition, the mechanism of action of anti-static masterbatch is that the crystallinity of the polymer also has a significant impact on the migration degree of additives.