From lacquer, tung oil to paint, water-based paint, furniture coatings have experienced these!

lacquer had a very long history, and the archaeologists found a lacquer bowl at Hemudu site, which was more than 7,000 years old.

One: the origin of "lacquer"

The lacquer character of the seal script

lacquer had a very long history, and the archaeologists found a lacquer bowl at Hemudu site, which was more than 7,000 years old.

According to historical data, in the Neolithic period, the ancients had already recognized the properties of paint and used it to make ware. The composition of the word "lacquer" can also be proved: lacquer comes from sumach (lacque tree), and all the Chinese characters for the names of trees are from the wood, such as: pine, cypress, beech, Yang, etc., but the word "lacquer" comes from water.

Because the SAP flows from the trunk of this tree, it is called "桼" : 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 sumac, the man and the paint. There is a saying in Zhuangzi: "Paint is available, so cut it", which is the earliest record on the mining and cutting of raw paint in China.

Two: lacquer and sumac

Chinese lacquer; Chinese Lacquer; japan; Japanlac), also known as natural lacquer, raw lacquer, soil lacquer, national lacquer. People in the past did not know the chemical principle on which the lacquer was made, but mastered the mystery of the lacquer through continuous observation and practice.

The lacquer liquid naturally secreted from the sumac tree will form a black shiny film after the sun, which attracted the attention of ancient people and wondered how to use it. Gradually, people learned to collect more lacquer from the tree and brush it on the objects, which became the original lacquer.

The artificial cultivation of lacquer tree came into being, the Book of Songs recorded: "In the Fang of Ding, it was made in the Chu Palace, and in the Chu room, it was made of hazel, chestnut, Tong, catalpa and lacquer", indicating that lacquer tree had become an economic tree in the pre-Qin period.

Characteristics of sumac

Sumac is a deciduous tree with a height of up to 20 meters. The leaves are oval, with yellow-green flowers in early summer and oblate fruit in autumn. Sumac is widely distributed in China, and the provinces around the Sichuan Basin are its distribution centers, because the climate in these areas is warm and moist, which is very suitable for the growth of sumac.

Lacquer trees more than eight years can produce paint. Farmers use mussel shells to cut the bark, insert mussel shells or bamboo pieces under the knife edge, collect the paint into wooden barrels, sealed with oil paper and stored.

The natural paint cut from the sumac is called raw paint, and the cooked paint refers to the raw paint after sunshine, stirring, and incorporation of tung oil oxidation.

The main component of the paint is urushiol, and other tree gum, nitrogen, water and trace amounts of volatile acid, etc., just cut the paint is milky and sticky, and the oxidation color becomes darker after contact with the air, and finally becomes the chestnut shell color.

Raw paint is difficult to be adjusted into bright color paint, because the raw paint itself is deep in color, the pigment is added to it, it is easy to be conquered by the raw paint primary color, so the ancient lacquer is mostly black and red.

"Zhu men wine and meat stink, the road has frozen bones", Du Fu's poem in the red lacquer gate in the feudal period is the official special, ordinary people in order to avoid suspicion most choose black paint.

As the saying goes, "All paint does not say color is black", and now people also use "black" to describe the black of the night. As for making the raw paint black, rust water can be mixed into the paint, iron oxide and urushiol color reaction, stir evenly, brush on the object, black as ink. This kind of black paint is also called black paint and dark paint.

Although lacquer belongs to natural plant paint, but some people contact the dry paint will be allergic to the skin, and even smell the smell of lacquer can also get a rash. In this case, the old masters will say that they are "bitten" by lacquer, in fact, this is lacquer allergy. In general, no special treatment is required, and it will heal itself in about seven days.

The application of lacquer coating has a long stream, which is famous at all times and at home and abroad. It has a small impact on the environment, and has the effect of waterproof, insect-proof, bactericidal and anti-corrosion. Besides, the paint has a strong endurance to acid, salt and moisture.

Its function can not only beautify, but also protect objects, has been regarded as the first choice of ideal paint, paint industry is therefore very prosperous and enduring.

Lacquer and porcelain are regarded as the symbol of Eastern civilization, and later spread to Japan, because the Japanese rely on lacquer far more than other nationalities in life, Westerners therefore call lacquer "Japan" and porcelain "China".

The Great lacquer encountered real challenges in the 20th century. Due to the limitations of single variety, low labor productivity, low mass degree and high cost, with the emergence of modern chemical coatings, the scope of application of lacquer is becoming narrower and narrower.

Due to the cheap raw materials of chemical coatings, easy mass production, low cost, multiple functions and wide application, it has almost replaced the traditional coatings which have been applied for thousands of years.

Three: Tung oil

Because of the limited production of lacquer, the ancients found tung oil, tung oil is easier to obtain than lacquer, and the cost is lower, so the ancients often mixed tung oil in lacquer, oil and paint mixed, learn from each other's strengths, make the best use of everything, which can be described as a pioneering work, the word paint is thus produced.

The seeds of the tung tree used for oil extraction

Tung oil is an industrial vegetable oil which is extracted from the seeds of tung tree by mechanical pressing and processing. The oil content of aleurites seeds is generally more than 35%, and the oil content of seed kernel is about 60%.

Tung oil is also called embryo oil, the appearance of light yellow, drying speed is slow, and the transparency and viscosity of the film is poor, can not be directly used as painting.

Raw tung oil after high temperature boil, and add rosin as a desiccant, after precision filtration into cooked tung oil, stability and painting effect is greatly improved, the oil film texture is obvious, both has a certain hardness, and has good ductility and elasticity, but the anti-aging performance is not as good as lacquer.

The cooking process of cooked tung oil is complicated, and the sensitivity to oil temperature is high. There is no uniform quality standard for tung oil products on the market, which can be used for painting, but the expected effect cannot be guaranteed.

Some poor quality of cooked tung oil film will appear frost, mesh, silk and other phenomena.

Tung oil is very widely used, it is the main raw material for the manufacture of paint and ink, and can make oilcloth, oil paper, soap, pesticides and medical vomiting agents, pesticides and so on.

Historically, the most common use of tung oil is the preservation of ancient wood buildings, which is not only cheap, but also quite good.

The aleuric acid contained in tung oil is irritating to mucous membrane, and will damage liver and kidney after absorption. The smell of raw tung oil volatilized aleuric acid is much larger than that of cooked tung oil.

In particular, it should be noted that the appearance of tung oil is similar to cooking oil, but can not be eaten, if ingested will lead to severe vomiting. If the cooking oil is mixed with a small amount of tung oil, it is more dangerous, long-term consumption may cause subacute poisoning.