Conductive plastic is a kind of functional polymer material, which is mixed with resin and conductive material and processed by plastic processing. Mainly used in electronics, integrated circuit packaging, electromagnetic wave shielding and other fields.

Conductive plastics have not only been rapidly applied in anti-static additives, computer anti electromagnetic screens and smart windows, but also have a wide range of applications in light-emitting diodes, solar cells, mobile phones, micro TV screens and even life science research. In addition, the combination of conductive plastics and nano technology will also promote the rapid development of molecular electronics.

I. primary uses and types of conductive plastics

(1) anti static turnover box, IC and LCD tray, IC package, chip carrier, film bag, etc. used in the production of fine electronic components such as integrated circuit, chip, sensor sheath, etc. in the field of electronics and electrical appliances.

(2) the shell and structural parts of explosion-proof products, such as the shell and structural parts of electrical products used in coal mines, oil tankers, oil fields, dust and combustible gases.

(3) semi conductive shielding materials used in medium and high voltage cables.

(4) EMI shielding shell of electrical products in the fields of telecommunication, computer, automation system, industrial electronic products, consumer electronic products, car electronic products, etc.

(5) conductive plastics generally include conductive PP, conductive PE, conductive ABS, conductive PS, conductive MPPO, conductive PPO, conductive PPE, conductive nylon PA, conductive PBT, conductive PC, conductive PPS, conductive Pei, conductive Pu, conductive TPR, conductive TPV, conductive TPE, conductive ABS, conductive EVA, conductive K adhesive, conductive pc/abs, conductive pc/pbt, conductive pvc/abs, conductive EPDM, conductive sis, conductive SBS, conductive PMMA, conductive POM, conductive PPR, conductive PPA Conductive rubber, etc.

II. Development of conductive plastics at home and abroad

1. Antistatic filling type

The advantage of antistatic agent filled products is that the coloring of the products is not restricted, and the low molecular antistatic agent has little effect on the product function, and its surface resistivity is 1010-1013 Ω. However, the electrical function of low molecular antistatic agent filled products will gradually lose over time.

At present, the primary development intention of foreign countries is to develop and produce high molecular antistatic agent, which can also be called permanent antistatic agent. It will not lose its conductivity after washing or long-term use like low molecular antistatic agent. The main types of high molecular antistatic agents are: polyether type, quaternary ammonium salt type, sulfonic acid type, acid graft copolymer and ionic type. The leading manufacturers include Sanyo Huacheng, Sumitomo specialty chemicals, Sumitomo science industry and industrial pharmacy in Japan, Ciba Specialty Chemicals and Klein in in Switzerland, and Waco and Dahu in the United States. The addition amount of high molecular antistatic agent is 5-15 times that of low molecular antistatic agent. The compatibility with resin should be considered to select the appropriate compatibilizer. Due to the restriction of cost, its application is bound. At present, low molecular type antistatic agents, especially ionic antistatic agents, are mainly used in China. They are easy to appear and are greatly affected by environmental humidity.

2. Carbon filled type

The main fillers in this series are conductive carbon black, graphite and carbon fiber. The volume resistivity of the finished product is 102-109 Ω· cm. Meanwhile, carbon black filling is the mainstream. The reason why carbon black filled conductive polymers are widely used is that the price of conductive carbon black is relatively low; Second, because carbon black can be selected according to different conductivity requirements, the resistance value of its finished products can vary in a wide range of 102-109 Ω; Third, the conductivity is durable and stable; Therefore, it is an ideal antistatic material. However, its finished products are only limited to black, which has a great impact on the data function, and requires supporting modification skills. In order to improve and improve the resistance of conductive plastics, adhere to better physical properties and excellent and stable conductive function.

3. Metal filled type

This kind of conductive plastic is mainly used for electromagnetic wave shielding. In recent years, due to the development of integrated circuit and large-scale integrated circuit skills, digital electronic machines have been developed from industrial use to civilian use. In order to improve the processing ability, the electronic circuits and components used are more and more integrated, miniaturized and high-speed, and the signal level is reduced, which makes the electromagnetic wave invaded from the outside close to the control signal. In addition, electronic equipment also radiates electromagnetic waves, so it is easy to cause malfunction, image and sound disturbance of electronic machines. In the 1980s, the shells of electronic machines mostly used plastic materials instead of metal. This is because the plastic shell has the advantages of light weight, high strength, corrosion resistance, easy processing, high production efficiency and low total cost. However, plastic is an insulator, and electromagnetic waves can be transmitted completely. Therefore, endowing the plastic shell with electromagnetic wave shielding ability has become a very urgent subject to be studied.

Source: Jiangmen engineering plastics http://www.wywantong.com/