Chinese wax

China wax, also called Pelawachs, is a substance that is obtained from the secretion of Chinese wax scale insects.

Properties

China wax is a white to slightly yellowish, water-insoluble substance. The wax comprises a mixture of esters of fatty acids (C24 -28) and long-chain fatty alcohols containing 24 to 32 carbon atoms per chain, for example the cerotic acid or the Lignocerinsäureester of ceryl alcohol.

The melting point is between 80 and 84 ° C. The density is relatively high, and is 0.95 to 0.97 g/cm3. China wax is almost odorless. The iodine value is 1 to 2, the acid number between 0.2 and 1.5. The saponification number is 73 to 93

Extraction

The wax is deposited by the male larvae of Wachsschildlausarten coccus ceriferus and Ceroplastes ceriferus. In Ericerus pela divorce both male and female insects from the wax. After the infestation of trees up to one centimeter thick layer of wax on the branches of infested trees is deposited in approximately 90 to 100 days. To obtain the wax is scraped off by the trees and melted in a water bath. The obtained as by- product insects are used as animal feed.

The accumulated amount of wax depends on the used plants, the insects used as well as the climatic conditions such as temperature, humidity and sunshine duration.

The wax production by Ericerus pela is known in China for over a thousand years. The production reached 6,000 tons per year by 1900 a peak. The advent of electric lighting, and the availability of paraffin waxes led to a decline in candle making and thus the China wax extraction. In the nineties, around 500 tonnes a year yet been obtained.

Use

China wax is used in polishes and particularly in the manufacture of candles. In Chinese medicine, Chinese wax is used for hoarseness, pain relief, with worm infestation and nervousness. Externally it is used as an ointment for treating wounds. Other applications are tablet coatings, paper coating and leather polish. In the visual arts China wax was used.

Saponification

By saponification of China wax can policosanols, a mixture of long-chain aliphatic C 24 - 32 alcohols gain. This is attributed to a beneficial effect on the disorder of the lipid metabolism and the reduction of platelet aggregation. In Germany policosanols are not yet approved as a drug.