Antistatic Coating

Posted by RachelHJM on May 12th, 2017

Anti-static special coatings:

In general, there are two manufacturing methods of antistatic coating, that is, adding antistatic agent or conductive material to the resin. Add antistatic agent such as quaternary ammonium salt in the resin, and coat the resin surface with 0.1-10 (mass fraction) antistatic agent such as polyolefin, which brings the ability of permanently restoring and accumulating electrostatic charge. Besides, people can add conductive substance such as inorganic carbon black or silver powder to the resin to prevent static electricity while silver is expensive.

Anti-static special paint

The existing ordinary paint mainly has two flaws in the fire safety: First, it is flammable for it has flammable ingredients and there can be a fire easily. It burns fast and there can be a fire easily. The fire spreads quickly and easily causes huge losses if the fire is not put out in time.

Second, it generates a lot of static electricity. Due to mutual friction between objects, static electricity easily accumulates and brings electrostatic hazards. It may interfere in normal operation of the electronic computer and precision instruments. In severe cases, it may discharge and produce spark, resulting in explosion and fire. As one of the anti-static raw materials, conductive carbon black can be added into the paint which effectively removes static electricity.

Acetylene carbon black has high purity, over 99.5% of carbon content, less than O.1% of hydrogen content, and O.07%～0.26% of oxygen content. Its pH value is 5-7. With low resistivity, it boasts excellent electrical conductivity, thermal conductivity and anti-static effect.

Add acetylene carbon black to acrylate/vinyl acetate copolymer emulsion as antistatic agent to make antistatic emulsion pressure sensitive adhesive. When 1.2% is added, conductivity reaches 7.2 × 103Q, and the adhesive can be used for bonding electrostatic PVC flooring. It can be also used as conductive filler for making conductive adhesives that don’t require high conductivity.

The advantages and disadvantages of the carbon black, metal conductive media, metal oxide compound conductive powder as the antistatic agent are as follows:

(1) Carbon-based conductive materials are mainly graphite and carbon black which are often used in antistatic coating, paints and adhesives for their high conductivity and cheap price. However, for they have great specific surface area and high oil absorption volume, certain addition when making solvent-free antistatic coating will increase coating viscosity and worsen self-leveling deterioration. Therefore, they can be only used as auxiliary conductive material. But they can be used for making solvent-based antistatic coating and conductive putty while the coat colors are either black or dark.

(2) Metal conductive medium: It boasts good conductivity but the paint color is restricted by the color of the metal powder. Such powder has large proportion and settles easily in the paint film and easily oxidates if it contacts with air (while inert metal is expensive), which results in unstable conductive performance of the coating.

(3) Metal oxide compound conductive powder: With light color, it can produce all kinds of antistatic coatings, and its conductive property can meet the basic requirements with moderate oil absorption and a high price.