The use, classification, advantages and disadvantages of conductive coatings

Conductive coatings have been developed for about half a century. The first open conductive coating was in 1948, when the United States patented silver and epoxy resins as conductive adhesives. In the 1950s, China also began to study and apply conductive coatings

. In recent decades, conductive coatings have been used in electronics, electrical appliances, aviation, chemicals, printing and other military and civil industries. Correspondingly, the theoretical research of conductive coatings has also been developed rapidly, and promoted the increasing maturity and perfection of applied technology. According to the classification of application materials, conductive materials can be divided into conductive coatings and doped conductive coatings.
-type conductive coating refers to the conductive coating made of this-type conductive polymer as a film-forming substance. This type of conductive coating is mainly used in anti-corrosion anti-static paint, absorbent coating, electromagnetic shielding coating.
-doped conductive coating refers to the addition of conductive substances on the basis of polymer polymers, using the conductive effect of conductive substances. Commonly used conductive fillers are metal-based fillers, carbon-based fillers, metal oxide-based fillers, composite fillers, new nano-conductive fillers, etc. Because doped conductive coatings are cheap and easy to use, they are widely used.
, conductive coatings can also be divided according to the characteristics of the application: conductive coatings, radiation shielding coatings, anti-static coatings and so on.
the importance of anti-static coatings, the next specific introduction to anti-static coatings.
29, 2019, a fire broke out in Ningbo Ritchie Daily Products Co., Ltd. The accident killed 19 people and injured three others, with a total area of about 1100m2. The accident investigation team investigation determined that the direct cause of the accident is the Company employee Sun a song after the heated isomer alkane mixture poured into a plastic bucket, due to electrostic discharge caused by combustible vapor fire and spread into a disaster after the fire, the employee tried to blow out with his mouth, and fan fire, eventually leading to the spread of the fire.
the dangers of static electricity are obvious to all. According to incomplete statistics, in recent years, China's petrochemical enterprises have had a number of static accidents, losses of hundreds of millions of dollars. Even in life, static electricity-induced fires are everywhere.
can produce static electricity at any time, anywhere people live. In industrial production, static electricity can cause electromagnetic interference, causing the failure or wrong action of electronic equipment, in the production, storage place and equipment of flammable and explosive products or dust, oil mist, equipment can easily cause explosion and fire, and other hazards that are not conducive to production operations and affect product quality.
it is almost impossible to completely eliminate static electricity, but some measures can be taken to control static electricity so that it does not cause harm. For example: the use of conductive electrostitive coating for anti-corrosion conductive electrostitive coating is the most common means of prevention and treatment. Anti-static coatings can conduct electricity, mainly because of the addition of conductive materials between the contact and link, forming a conductive path, and ultimately achieve the effect of anti-static.
anti-static coatings on the market, basically doped conductive coatings. Therefore, anti-static coatings are also divided into: metal system (silver, copper, nickel, zinc, etc.), carbon system (conductive graphite or carbon black), metal oxide system (tin oxide, zinc oxide, titanium dioxide treatment, tin oxide added, etc.) and so on.
Carbon-based conductive coatings
carbon-based conductive coatings are an old material, used as carbon-based conductive coatings conductive fillers are mainly graphite, a variety of carbon black, graphite fiber, carbon fiber, high-temperature calcined petroleum coke and silicon carbide. It has the advantages of cheap price, low density, not easy to sink, strong corrosion resistance and so on. However, the conductivity is relatively poor, and because the surface contains a large number of polar groups, there are difficult to disperse, easy flocculation and other shortcomings. Colors can only be black or dark.
With the development of nanotechnology, the composite of graphite nanomaterials and substations to conductive polymer materials is rising day by day, and the expansion of graphite as a new type of conductive filler, with good conductivity, small friction loss, small pollution and other advantages.the conductivity of
metal conductive coatings
metal conductive coatings depends on the type of metal filler, quantity, type of metal fiber and metal powder, quantity, shape of filler, conductivity can basically meet the requirements, but the color of the coating is limited by the color of the metal powder. Metal fillers are mainly silver powder, nickel powder, copper powder and zinc powder. Because silver powder is more expensive, it is mostly used in the military field and less used in civilian use. Although the price of copper powder is low, but easy to oxidize, conductivity is unstable.
Metallic oxide conductive coatings
metal oxides due to its excellent conductivity, light color, better complement the metal conductive pigment corrosion resistance and carbon conductive pigment decoration performance and other shortcomings. Common composite fillers are glass beads, copper powder and mica powder outsourcing silver powder and carbon black outsourcing nickel powder and so on. Metal oxide conductive pigments are mainly doped with tin oxide, zinc oxide, molybdenum dioxide and so on.
conductivity of a conductive coating usually has three characteristics: volume resistivity or conductivity; There is customer feedback, there is always the purchase of products with press-type meters to measure the surface resistance "non-conformity" problem exists.
, "First of all, there is no national standard or industry standard approved with a pressed resistance test table. In the national standard for the conductive static/static dissipative material test equipment and methods, there are clear requirements: test electrode weight and size, different resistance range of the test voltage caused by the resistance measurement results are large mainly due to the pressure gauge output voltage is only 9V, measuring the surface resistance in 10 3-5 times the sample, the measurement results are relatively accurate. When measuring a model with a surface resistance of 6-9 times in 10, the result is too large due to the low test voltage provided.
addition, the pressure meter and powder model contact is not sufficient, contact area can not meet the requirements of the national standard, resulting in a large resistance test results, such as encountering pattern powder on the impact of greater. "
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