早使用的絕緣材料為棉布、絲綢、云母、橡膠等天然制品。在20世紀(jì)初，工業(yè)合成塑料酚醛樹脂首先問世，其電性能好，耐熱性高。以后又相繼出現(xiàn)了性能更好的脲醛樹脂、醇酸樹脂。三氯聯(lián)苯合成絕緣油的出現(xiàn)使電力電容器的比特性出現(xiàn)了一次飛躍(但因有害人體健康，后已停止使用)。同期還合成了六氟化硫。

 

The earliest insulating materials are cotton, silk, mica, rubber and other natural products. At the beginning of the 20th century, industrial synthetic plastic phenolic resin was first introduced. It has good electrical properties and high heat resistance. Later, urea-formaldehyde resin and alkyd resin with better properties appeared successively. The emergence of trichlorobiphenyl synthetic insulating oil has made a leap in the specific characteristics of power capacitors (but since harmful to human health, it has stopped using). Sulfur hexafluoride was also synthesized at the same time.

 

30年代以來人工合成絕緣材料得到了迅速發(fā)展，主要有縮醛樹脂、氯丁橡膠、聚氯乙烯、丁苯橡膠、聚酰胺、三聚氰胺、聚乙烯及性能優(yōu)異稱之為塑料王的聚四氟乙烯等。這些合成材料的出現(xiàn)，對電工技術(shù)的發(fā)展起了重大作用。如縮醛漆包線用于電機(jī)，使其工作溫度和 可靠性提高，而電機(jī)的體積和重量大大降低。玻璃纖維及其編織帶的研制成功及有機(jī)硅樹脂的合成又為電機(jī)絕緣增加了H級這個耐熱等級。

 

Since the 1930s, synthetic insulating materials have developed rapidly, mainly acetal resins, chloroprene rubber, polyvinyl chloride, styrene-butadiene rubber, polyamide, melamine, polyethylene and polytetrafluoroethylene, which are called the king of plastics. The emergence of these synthetic materials has played an important role in the development of electrical technology. For example, enameled acetal wires are used in motors to improve their working temperature and reliability, while the volume and weight of motors are greatly reduced. Successful development of glass fiber and its braided tape and synthesis of organic silicone resin have increased the heat-resistant grade of H for motor insulation.

 

40年代以后不飽和聚酯、環(huán)氧樹脂問世。粉云母紙的出現(xiàn)使人們擺脫了片云母資源匱乏的困境。

 

Unsaturated polyester and epoxy resin came out after the 1940s. The emergence of mica paper has freed people from the plight of lack of mica resources.

 

50年代以來，合成樹脂為基的新材料得到了廣泛應(yīng)用，如不飽和聚酯和環(huán)氧等絕緣膠可供高壓電機(jī)線圈浸漬用。聚酯系列產(chǎn)品在電機(jī)槽襯絕緣、漆包線及浸漬漆中使用，發(fā)展了E級和B級低壓電機(jī)絕緣，使電機(jī)的體積和重量進(jìn)一步下降。六氟化硫開始用于高壓電器，并使之向大容量小型化發(fā)展。斷路器的空氣絕緣及變壓器的油和紙絕緣部分地被六氟化硫所取代。

 

Since the 1950s, synthetic resin-based new materials have been widely used, such as unsaturated polyester and epoxy insulating adhesives for impregnation of high voltage motor coils. The application of polyester series products in the insulation of motor slot lining, enameled wire and impregnating paint has developed the insulation of E-class and B-class low-voltage motors, which further reduces the volume and weight of motors. Sulfur hexafluoride has begun to be used in high voltage electrical appliances and is developing towards large capacity and miniaturization. Air insulation of circuit breakers and oil and paper insulation of transformers are partly replaced by sulfur hexafluoride.

 

60年代含雜環(huán)和芳環(huán)的耐熱樹脂得到了大發(fā)展，如聚酰亞胺、聚芳酰胺、聚芳砜、聚苯硫醚等屬 H級及更高耐熱等級的材料。這些耐熱材料的合成為以后發(fā)展 F級、H級電機(jī)創(chuàng)造了有利條件。聚丙烯薄膜在這一時期也成功地用于電力電容器。

 

In the 1960s, the heat-resistant resins containing heterocyclic and aromatic rings were greatly developed, such as polyimide, polyaromatic amide, polyaromatic sulfone, polyphenylene sulfide and other materials belonging to H-grade and higher heat-resistant grade. The synthesis of these heat-resistant materials has created favorable conditions for the development of F and H class motors in the future. Polypropylene film was also successfully used in power capacitors during this period.

 

70年代以來新材料的開發(fā)研究相對比較少，這一時期主要是對現(xiàn)有材料進(jìn)行各種改性及擴(kuò)大應(yīng)用范圍。對礦物絕緣油采用新方法精制以降低其損耗;環(huán)氧云母絕緣在提高其機(jī)械性能和實現(xiàn)無氣隙以提高其電性能方面做了很多改進(jìn)。電力電容器由紙膜復(fù)合結(jié)構(gòu)向全膜結(jié)構(gòu)過渡。1000千伏級特高壓電力電纜開始研究用合成紙絕緣取代傳統(tǒng)的天然纖維紙。無公害絕緣材料70年代以來也發(fā)展很快，如以無毒介質(zhì)異丙基聯(lián)苯、酯類油取代有毒介質(zhì)氯化聯(lián)苯，無溶劑漆的擴(kuò)大應(yīng)用等。隨著家用電器的普及，其絕緣材料著火而導(dǎo)致重大火災(zāi)事故屢有發(fā)生，所以對阻燃材料的研究引起了重視。

 

Since the 1970s, the development and research of new materials are relatively few. In this period, the existing materials are mainly modified and applied in a wide range. The mineral insulating oil is refined by a new method to reduce its loss, and the epoxy mica insulation has made many improvements in improving its mechanical properties and realizing no air gap to improve its electrical properties. Power capacitors are transformed from PAPER-FILM composite structure to full-film structure. 1000 KV UHV power cable began to study the replacement of traditional natural fibre paper with synthetic paper insulation. Pollution-free insulating materials have also developed rapidly since the 1970s, such as replacing toxic medium chlorinated biphenyl with non-toxic medium isopropyl biphenyl and ester oil, and expanding application of solvent-free paint. With the popularity of household electrical appliances, the ignition of insulating materials leads to frequent major fire accidents, so the study of flame retardant materials has attracted much attention.