AntistaticMasterbatches.pdfVIP

Antistatic Masterbatches Introduction: By virtue of their insulating nature, polymers of all types allow static charge to build-up on their surfaces, particularly in the case of films and fibers, which have large surface area to volume ratio. Such static charge build-up leads to several undesirable consequences in the final product. For instance, built-up static charge can attract dust onto a food package, which is undesirable aesthetically. At times, static charge can damage circuit boards in electronics packaging and may cause hazards of fire or explosion in the vicinity of flammable materials. The static charge may also cause several processing problems such as difficulty in winding of films or melt-spun fibers, agglomeration of powders during transport, adhesion of films during processing, etc. Such undesirable effects of static charge build-up can be avoided by using masterbatches containing antistatic agents. The most commonly used are those compounded internally with the polymer and those applied topically. Migratory Antistats: The traditional internal antistats are migratory in nature. Typically these migratory antistatic agents have a hydrophobic organic end and a hydrophilic end. The strongly polar hydrophilic end adsorbs water molecules which eliminate static charges by ionic conduction. The long hydrocarbon chain length constitutes the hydrophobic group and controls the rate of diffusion (or migration) of the antistat to the surface of the polymer product. There are three major classes of internal, migratory antistatic agents: esters, amines and amides. Glycerol mono-stearate is commonly used as an antistatic agent for PE and PP but is useful for only short term antistatic performance of about 1-2 months. The amines and amides are usually ethoxylated products and are more useful for long term antistatic performance. The amine type antistats tend to react with polycarbonate, which is commonly used in making