Text | Number Seven - Song
Chameleons are naturally renowned masters of disguise. According to research, it appeared about 70-80 million years ago. But this small animal, which was good at camouflage, was not discovered by scientists until 1758.
How cool it is to be able to change colors with the environment. Since then, humanity's love for chameleons has been out of control. I don't know which year, some people opened their minds and put forward a hypothesis - the car is a "mechanical creature", can it also have such a capability?
Don't think it's incredible, in fact, throughout the history of automobile development, variable paint has formed a force to push the times forward.
A historical attempt at variable paint
Although the history of car paint is long, from the first car developed by Carl Benz in 1886, until the heyday of the Ford Model T, the paint was dominated by dark black, and it seemed that all the light would be engulfed by it, and there was no change or texture.
At that time, car paint was made according to several natural substances, the most common ingredients were flaxseed oil, pine oil, van li water, carbon black. In 1929, DuPont introduced the first alkyd magnetic paint made of synthetic resin alkyd resin, which greatly improved its gloss. The car paint with high gloss is more "sensitive" to light. For example, the following figure proves this very well, ~ the number plate is illuminated by light, and there is no more layer on the large board.
The light source in the picture is the D65 light source, which can simulate artificial daylight, to ensure that indoors, rainy days when observing the color effect of the object, there is a lighting effect similar to the observation under the sunlight, so this texture is consistent with the real use
Six years later, DuPont launched the automotive paint grading system, breaking the situation of domination by the original black automotive paint. By this time, the texture of the paint has been greatly improved, although it cannot achieve discoloration, but under different lights, the layering of the paint is stronger.
Variable paint methods that have been implemented
Entering this century, it is Mazda that is leading the development of technology. Mazda's soul red can show different color strengths and weaknesses in different environments, and the texture is very high.
In the highlight section, the light that encounters the aluminum powder of the reflective layer folds back will make the high chroma red of the translucent layer more vivid. In the shadow part, the reds of the transmitting layer and the reflective layer overlap each other, showing a deep red. With this design, the visual effect of the body paint will produce subtle dynamic changes with the change of light, like a living creature, showing a bright and rich expression.
Later, the Soul Crystal Red they introduced further enhanced this ability. For example, its paint particles are polished smaller than the general paint, and higher gloss can be obtained after spraying. Moreover, in the field of general family cars, Mazda is also the first car brand to emphasize the weakening of the strong waistline, through the body type and the car paint to reflect the sense of strength, which also directly enhances the attention of the car paint.
Now, Mazda's thinking is considered a development trend. Although the color of the car paint has not changed significantly, it is still dominated by a certain hue, and the chroma has changed, but such an improvement is enough to surprise people.
Possible way to be implemented: thermal paint
Heat-sensitive paint is also known as heat-sensitive temperature-changing paint, as the name suggests, its principle is to use the difference in temperature to control the change of color. Note that this is a new idea, and it is different from the light and shadow changes mentioned above. The idea is that the paint color changes at different temperatures. For example, it is white in winter and red in summer, so this setting is also very good.
According to the classification of species, there are two kinds of thermal paints, reversible and irreversible. Car paint obviously requires reversible heat-sensitive paint. In the aftermarket, thermal car paint is already the new favorite of some RMB players. For example, in the picture below, a pot of hot water is sprinkled down, and the paint of the car is immediately changed.
In motor vehicles, irreversible heat-sensitive paint also has its uses. For example, engineers applied this thermal paint to the brake discs of the Yamaha YZF-R1 to achieve overtemperature measurement.
The engineers used several different pigments, such as green at 430°C and orange at 560°C
In fact, in the industrial field, thermal paint has been used for a long time. For example, in the last century, it was used in generators, artillery shells, aircraft and other surfaces for non-destructive flaw detection or non-destructive temperature measurement.
However, the lightfastness of thermal paint is very poor, and exposure to strong sunlight will lead to fading failure. At the same time, its life is only a few months, and it has to be repainted after failure, coupled with its poor heat resistance, and degradation will occur after a long time. The cost of using the car is a matter of great concern to everyone, if it is only for personality and beauty, the excessive cost of painting will dissuade many people.
In short, thermal paint is a good choice for automotive variable paints. But to achieve large-area applications, it also needs to overcome cost and technical shortcomings.
A more cerebral approach: "e-ink"
This year, BMW has developed a third variable car paint idea - "electronic ink (E-ink)" technology.
Dynamic display of electronic ink (E-ink) for bmw iX new cars
The technology was showcased at ces 2022 (International Consumer Electronics Show), which opened in January. BMW E-ink's idea is the same as the e-book Kindle, its electronic ink is actually millions of transparent microencapsules, these capsules contain negatively charged white and positively charged black particles, which are suspended in a transparent liquid, controlled by controlling the electrodes on both sides of the microcapsule, to achieve a rich change in the color of the paint.
As can be seen from this figure, through the electrode control, black and color-changing pigments can be arranged to varying degrees, so that the color changes
You might ask, the BMW iX can only show black and white variations, like watching black and white TV. You don't have to worry, with black-and-white TV, will color TV be far away?
According to the latest technology announced by E Ink in this field, they have also developed four-color electronic ink, their E Ink Spectra 3100 four-color electronic ink system, using black, white, red and yellow particles, providing four bright and saturated colors, can show a rich variety of information and content.
However, because the car paint has to withstand a variety of harsh natural environments, how durable BMW's electronic ink is still unknown. However, the two variable car paints mentioned above are mainly in the field of material science and technology, and BMW is injected with electronic technology to achieve a leap, which is of great pioneering significance. I hope that BMW can mass-produce this technology as soon as possible and bring us a fresh experience.
summary
Only one car paint color can be owned, which is really greasy. Can car paint be like a chameleon, showing different colors and textures in different environments?
Throughout the historical development, variable paint technology has appeared three ideas: 1, on the basis of traditional car paint technology, through complex coatings and structures, with the body profile design, to achieve chromaticity and light and shadow changes; 2, the use of heat-sensitive paint this new car paint technology, at different temperatures, reflecting different car paint coating effects; 3, add electronic technology, the car paint armed as an "electronic screen", freely realize the change of car paint.
Hopefully, these technologies will become more and more stable and cost-effective, so that we can all experience its charm firsthand.