Lacquer has a very long history. Archaeologists found a lacquered wooden bowl at Hemudu site, which has a history of more than 7000 years.
1： The origin of lacquer
Seal script writing of lacquer characters
Lacquer has a very long history. Archaeologists found a lacquered wooden bowl at Hemudu site. It has been more than 7000 years since it was painted.
According to historical data, in the Neolithic period, the ancients had realized the performance of lacquer and used it to make utensils. The composition of the word "lacquer" can also be proved: Lacquer comes from sumach (lacque tree), and the Chinese characters of all tree names are from the side of wood, such as pine, cypress, beech, poplar, etc., only the word "lacquer" comes from water.
Because the sap will flow out of the trunk of this kind of tree, which is called the "Gong": the upper part is from the wood, the middle part is from the man, and the lower part is from the water, which vividly shows the relationship between the lacquer tree, the man and the lacquer liquid. There is a saying in Zhuangzi? The world of man: "lacquer can be used, so cut it". It is the earliest record of cutting raw lacquer in China.
2： Lacquer and lacquer tree
Chinese lacquer; Japan; japanlac, also known as natural paint, lacquer, earth paint and national paint. In the past, people did not know the chemical principle on which the paint was made, but they mastered the secret of the paint through continuous observation and practice.
The paint liquid naturally secreted from the lacquer tree will form a black and shiny paint film after being exposed to the sun, which has attracted the attention of the ancients, and how to use it. Slowly, people learned to collect more lacquer from the lacquer tree, brush it on the utensils, and it became the original lacquer.
The artificial cultivation of lacquer tree came into being. According to the book of songs, "among the fixed prescriptions, they were made in the palace of Chu, in the room of Chu, and in the room of Chu, they were made of hazel, chestnut, Tung, catalpa and lacquer". It shows that in the pre Qin period, lacquer tree had become an economic tree species.
Characteristics of lacquer tree
Lacquer tree is a deciduous tree, with a height of 20 meters. The leaves are oval, with yellow green flowers in early summer and oblate in autumn. Lacquer tree is widely distributed in China, and several provinces around Sichuan Basin are its distribution centers, because the climate in these areas is warm and humid, which is very suitable for the growth of lacquer tree.
Lacquer can be produced by lacquer trees over eight years. The bark of lacquer agricultural mussels is cut, the mussels or bamboo pieces are inserted under the knife edge, and the collected lacquer liquid is collected into the barrel and sealed with oil paper for preservation.
The natural lacquer liquid cut from the lacquer tree is called raw lacquer, while the cooked lacquer refers to the raw lacquer oxidized by the tung oil after sunlight and mixing.
The main composition of lacquer liquid is urushiol, and there are other resin, nitrogen, water and trace volatile acid. The lacquer liquid just cut is milky white and viscous. After contacting with air, the color of oxidation gradually darkens, and finally becomes chestnut shell color.
It's difficult to mix lacquer with bright colors, because lacquer itself has a deep color, and pigment can easily be conquered by the primary color of lacquer, so most ancient lacquerware is black and Zhu.
"Zhu men's wine and meat stink, and the road is frozen to death". Zhu Qi gate in Du Fu's poems was specially used by the government in the feudal period, and most ordinary people chose black paint to avoid suspicion.
As the saying goes, "every paint without color is black", now people still use "black one" to describe the darkness of the night. As for making the raw paint black, you can mix the rust water into the paint, and the iron oxide and urushiol react in color. After mixing evenly, brush on the object, dark as ink. This kind of black paint is also called black paint and black paint.
Although the lacquer belongs to natural plant paint, some people may be allergic to the wet lacquer and even have rashes when they smell it. In this case, the teachers will say that they are "bitten" by lacquer. In fact, this is lacquer allergy. Generally speaking, no special treatment is needed, and self-healing will take about seven days.
The application of lacquer has a long history and is famous all over the world. It has little impact on the environment. It has the functions of water-proof, insect proof, sterilization and anticorrosion. Besides, the paint has a strong endurance to acid, salt and humidity.
Its function is not only to beautify, but also to protect utensils. It has been regarded as the first choice of ideal coatings. Therefore, the paint industry is very prosperous and enduring.
Lacquerware and porcelain are regarded as the symbols of Oriental civilization, and later spread to Japan. Because Japanese rely on lacquerware far more than other nations in their life, Westerners call lacquerware "Japan" and porcelain "China".
The real challenge of lacquer in the 20th century. Due to the limitations of single variety, low labor productivity, low batch degree and high cost, the application range of paint is becoming narrower and narrower with the emergence of modern chemical paint.
Because of cheap raw materials, easy batch production, low cost, multiple functions and wide application, chemical coatings almost replace the traditional coatings which have been used for thousands of years.
3： Tung oil
Because of the limited production of lacquer, the ancients found tung oil, which was easier to obtain and cheaper than lacquer. Therefore, the ancients often mixed tung oil with lacquer to make up for the shortcomings and make the best use of everything. It can be described as an innovation. That's how the word paint came into being.
Tung tree seeds for oil extraction
Tung oil is a kind of industrial vegetable oil, which is made from the seeds of tung trees by mechanical pressing and processing. The oil content of tung oil seeds is generally more than 35%, and the oil content of kernel is about 60%.
Raw tung oil is also called embryo oil. Its appearance is light yellow, drying speed is slow, and the transparency and viscosity of the paint film are poor, so it can not be directly used for coating.
Raw tung oil is boiled at high temperature and rosin is added as desiccant. After precise filtration, it becomes mature tung oil. The stability and coating effect are greatly improved. The oil film texture is obvious, which has certain