Antistatic agents
As antistatics substances are referred to, which, as the additive added, the static charge preventing or attenuating objects.
- Singular: antistatic.
- Synonym: antistatic substances.
Technical application
Antistatic agents are used to prevent the undesirable effects of electrostatic charges caused by mechanical friction. Electrostatic charges can lead to undesirable attraction or repulsion effects or to sudden electrical discharges. Especially materials with a high electrical resistance - e.g. B. Plastics - are affected by such electrostatic effects and must therefore often be provided with an antistatic finish during molding or afterwards .
With antistatic agents u. a. achieves the following:
- Avoidance of dust and "standing" hair
- Avoidance of discharge sparks:
- Measures in electronics production, see ESD protection : ESD protective equipment, additive in tool handles, textiles, shoe soles, containers, work mats, etc.
- Textile finishing, fabric softener , film and fiber production
classification
- Internal or internal antistatic agents are incorporated into the material to be protected.
- External or external antistatic agents are applied to the objects to be protected.
- Conductive antistatic agents can be incorporated internally, for example as metal wires, or externally vapor-deposited as metal powder.
- So - called non - conductive antistatic agents are, for example, quaternary ammonium compounds (cf. Polyquaternium ) and surfactants . These can in turn be used as internal or external antistatic agents. The substances produce a very low electrical conductivity - they are referred to as electrostatic dissipative , as they slowly reduce the charge, which can, among other things. a. is important in electronics manufacturing.
An external antistatic agent is, for example, antistatic spray , it leaves a weakly conductive film on the sprayed objects.
Mode of action
Antistatic agents reduce electrostatic charge either by:
- an improved discharge of excess electrical charges, i.e. a lower ohmic resistance , or
- Reduction of friction.
Web links
- Encyclopedia ChemgaPedia (Fachinformationszentrum Chemie GmbH) "Antistatics" as a search term
literature
- Der Brockhaus, Naturwissenschaft und Technik, 2003, published by FA Brockhaus and Spektrum Akademischer Verlag. Part 1.
Individual evidence
- ^ Karlheinz Biederbick: Plastics. 4th edition, Vogel-Verlag, Würzburg 1977, ISBN 3-8023-0010-6 , p. 15.