01 About Dyes and Dyes

It is a familiar and ubiquitous color in daily life, with a long and rich history. As early as prehistoric times, humans began using natural dyes to add color to textiles. China used dyes such as madder, indigo, woad, and saffron as early as 3000 BC. Jia Sixie had already recorded the process of planting dye plants and extracting dyes in 'Qi Min Yao Shu'.

In modern times, in 1856, British chemist W H. Perkins discovered the first synthetic dye, aniline violet, ushering in a new era of chemical synthetic dye industry. Alkaline brown (azo dye), Congo red (direct dye), synthetic indigo, reduced blue (reducing dye), dispersed dye, phthalocyanine dye, and reactive dye have successively emerged.

02 About pigments

The earliest can be traced back to ancient times, as early as over 40000 BC, humans had already used primitive methods to heat loess into red pigment for body decoration. In 1704, a Prussian named Diesbach had an accident and originally intended to obtain red, but ended up producing blue. He accidentally synthesized Prussian blue, marking the beginning of artificial pigment synthesis. Another accident occurred when a chemist attempted to artificially synthesize quinine and produced a purple color called aniline violet, marking the beginning of modern pigments. With the development of the chemical industry, high-performance organic pigments continue to emerge, possessing excellent properties such as weather fastness, heat resistance, solvent resistance, and migration resistance.

Dyes and pigments

Dyes and pigments each have their own advantages and disadvantages. How to preserve the color of dyes while maintaining the stability of pigment structure, and preserve the transparency of dyes while maintaining the dispersibility of pigments. The technological giants in the industry have successively embarked on the path of dye coloring and pigment dyeing.

03 Dye Pigmentation

It mainly refers to transforming the characteristics of dyes into properties closer to pigments through some physical or chemical methods. That is to say, turning originally soluble dyes into insoluble states, making them mainly rely on physical means to adhere to the surface of objects like pigments to develop color. For example, in the field of printing, some printed materials with special gloss or texture requirements can better adhere to the surface of paper or other substrates after dye coloring, providing more vivid and lasting color effects, while accurately controlling the distribution and layering of colors.

Pigmentation of dyes can be achieved through physical coating, chemical grafting, and other methods, but the technical difficulty of physical coating makes it difficult to completely solve the problem of dye migration. Chemical grafting can solve most of the dye migration problems, but due to the wide variety and complex structure of dyes, chemical methods have to solve the grafting reactions of multiple dyes, which is difficult, costly, and has low benefits. The introduction of various macromolecules after grafting can affect the compatibility of downstream systems, greatly limiting the application range of dyes. Due to various reasons mentioned above, it is difficult to achieve breakthroughs in dye coloring.

04 Colorization of pigments

It is the process of uniformly dispersing pigment particles in the colored substance through physical methods, relying on external forces, mixing, extrusion, stirring, shearing and other processes, and transforming the properties of pigments into dye properties. Pigmentation allows pigments to enter the interior of the dyed object like dyes, rather than just adhering to the surface. This can avoid the problems of uneven surface color and color floating on the surface that may occur with traditional pigment dyeing. Due to its ability to penetrate deep into the interior of the dye, pigment dyeing can provide better dyeing depth. Compared to traditional pigments that only cover the surface, this method can make the color more rich and full.

Guangdong Hongkai's pigment dyeing preserves the excellent properties of the pigment itself, such as migration resistance, weather resistance, light resistance, and heat resistance. Through physical methods, the pigment is made to be around 50-200 nanometers, maximizing its transparency and brightness (as close as possible to about 90% of the dye). This not only maintains the excellent physical properties of the pigment, but also achieves or approximates (about 90%) the transparency and vividness of the dye as much as possible.