Whether it is dyes or pigments, they are all substances that can give people the color they need. The existence of red, orange, yellow, green, cyan, blue, and purple enriches our lives and makes the world a better place. colorful.
Pigments and dyes are both colored organic compounds. From the chemical structure of organic pigments and dyes, they are very similar. Even some organic compounds can be used as dyes and organic pigments, but organic pigments and dyes are indeed Two different concepts, so what is the fundamental difference between dyes and pigments?
01. Basic concepts
Dyes are organic compounds that can dye fibers or other substrates into a certain color. Most of them are soluble in water, or converted into a soluble state during dyeing through certain chemical treatments. Some dyes are insoluble in water but soluble in alcohol and oil, and can be used for the coloring of oil wax, plastic and other substances.
Pigments are colored organic or inorganic colored compounds that are insoluble in water and general organic solvents, but not all colored substances can be used as organic pigments. To become pigments, colored substances must have the following properties:
- The color is bright, which can give the colored object (or substrate) a firm color and luster
- Insoluble in water, organic solvent or application medium
- It is easy to disperse uniformly in the application, and it is not affected by the physical and chemical effects of the application medium during the whole dispersion process, and retains their own inherent crystal structure.
- Sunlight resistance, weather resistance, heat resistance, acid and alkali resistance and organic solvent resistance.
02. The coloring is different
The Dye is dissolved in the resin;
the pigment is uniformly dispersed in the resin.
03. Color variation
In the process of dyeing, dyes usually dissolve in the medium first, even disperse dyes or VAT dyes undergo a process of dissolving in water from the crystalline state to the molecular state, and then dyeing to the fiber. The color of the Dye itself does not represent the color of the fabric.
Pigments in the use of insoluble in the use of media, so always exist in the original crystal state, therefore, the color of the pigment itself represents its color on the srate.
04. For a variety of purposes
The main use of dyes is for Dyeing and Printing Textiles;
The traditional use of pigments is to non-textile (such as ink, paint, paint, plastic, rubber, etc.) for coloring. This is because dyes have an affinity (or directness) for textiles, can be adsorbed and fixed by fiber molecules, and pigments have no affinity for all coloring objects, mainly by resin, adhesive and other film-forming materials and coloring objects together.
05. Transparency contrast
The plastic made of dye is very transparent;
Pigment made of plastic transparency is much worse, do not rule out a transparent pigment, but transparency with dye or have a certain gap.