Polymers have high electrical resistances that lead to isolating properties. Antistatic agents act to reduce surface resistance and hence dissipate high electric charge densities on the surface of plastics. The reduction of the electrical charges on the surface of plastics will also reduce problems like dust contamination, risk of electrical discharge causing fire or explosion and electrical shocks or handling problems during transport, storage and packing.
An internal antistatic agent is incorporated and predispersed into the polymer matrix of the Masterbatch. Upon workup, the additive migrates to the surface of the polymer - because of its defined incompatibility with the polymer - where the additive builds up a uniform layer on the polymer's surface. The hydrophilic end projects out of the polymer, the lipophilic end anchors in the polymer. The protruding hydrophilic end absorbs moisture from the surrounding air and builds up a conductive path, reducing the surface resistance.
The migration rate of the antistatic agent from the bulk to the surface of the polymer depends from a number of factors. These include:
1. Chemical nature of the antistatic agent
- short-term antistats
Relative compatibility with the polymer. The less compatible an additive and polymers are, the faster the migration rate. Less compatible act within a few minutes to 24h. - long-term antistats
More compatible need up to 48h to migrate to the surface.
Combinations of them will result in synergistic properties.
2. Concentration of the antistat
Higher concentration -> quicker migration.
3. Temperature
Higher temperature -> increased migration.
Antistatic agents are hygroscopic, and mainly too high concentrations of antistatic agents will have an influence on printing and sealing properties.
For various different polymers Antistatic-Masterbatches are available, also compounds on the base of conductive carbon black. Please call for detailed information. Combinations with black, white, or grey are also available. Especially in combination with white, numerous sophisticated combinations with Slip, AO etc. are available.
Food contact approval
In general, nearly all of the active agents are admitted within the usual dosage, according to the BfR-recommendations.
The particular data can be taken out of the product information sheets.
Approvals of other authorities, especially FDA- and EC-approvals are present in most cases and are available, if required.
Do you have questions or do you need detailed product information?
Please contact us!
