China Suppliers Factory for Pigment Intermediates: Azo, Naphthalene, and Anthraquinone Based Products
Product Details
"Pigment intermediates" and the "dye intermediates" discussed in the previous round are essentially the same substance. They are both various aromatic hydrocarbon derivatives used in the production of dyes and organic pigments, and are key raw materials in the fine chemical industry.
The key difference lies not in the intermediate itself, but in the subsequent processing technology and the performance requirements of the final product—two dishes from the same raw material.
Classification and Properties of Pigment Intermediates
| Type | Core Raw Materials | Representative Intermediates | Main Characteristics | Typical Applications |
|---|---|---|---|---|
| Benzene-based | Benzene, toluene, chlorobenzene | 3,3'-Dichlorobenzidine, p-nitroaniline, 2,3-acid, red-based KD | Highest production volume, relatively low cost | Azo pigments (yellow, orange, red); broad chromatogram |
| Naphthalene-based | Naphthalene | 2-Naphthol, 2,3-acid, torpor acid, J acid, H acid | Contains sulfonic acid group; usually soluble in alkalis | Phenolic azo pigments and acidic pigments; vibrant colors |
| Anthraquinone-based | Anthracene | Anthraquinone, 1-aminoanthraquinone, bromoacetic acid | Excellent overall fastness; higher cost | High-performance anthraquinone reducing & acid pigments; outstanding lightfastness & heat resistance |
| Heterocyclic & High-Performance | Phthalic anhydride, urea, phthalonitrile, cyanuric chloride | Phthalocyanine, quinacridone, perylene tetracarboxylic anhydride, DPP intermediates | Most complex structure; top-tier performance | Phthalocyanine blue/green; quinacridone red; DPP red — automotive paints & high-grade inks |
Detailed Overview of Each Intermediate Type
Core raw materials include benzene, toluene, and chlorobenzene, with each molecule containing a benzene ring. Representative intermediates include 3,3'-dichlorobenzidine, p-nitroaniline, 2,3-acid, and red-based KD.
Main characteristics and uses: Highest production volume and relatively low cost. Used for synthesizing the highest-yielding azo pigments (yellow, orange, and red spectra), with a broad chromatogram, but some varieties have moderate fastness.
Core raw material is naphthalene, with each molecule containing a naphthalene ring. Representative intermediates include 2-naphthol, 2,3-acid, torpor acid, J acid, and H acid.
Main characteristics and uses: Contains a sulfonic acid group in its structure, usually soluble in alkalis. Used for synthesizing phenolic azo pigments and some acidic pigments, producing vibrant colors.
Core raw material is anthracene, with each molecule containing anthraquinone structures. Representative intermediates include anthraquinone, 1-aminoanthraquinone, and bromoacetic acid.
Main characteristics and uses: Excellent overall fastness, but higher cost. Used for the production of high-performance anthraquinone reducing pigments and acid pigments, exhibiting outstanding lightfastness and heat resistance.
Core raw materials include phthalic anhydride, urea, phthalonitrile, and cyanuric chloride. Representative intermediates include phthalocyanine, quinacridone, perylene tetracarboxylic anhydride, and DPP intermediates.
Main characteristics and applications: Most complex structure, difficult to synthesize, and possessing top-tier performance. Used for phthalocyanine pigments and high-end organic pigments — preferred for automotive paints and high-grade inks.
From Pigment Intermediate to Finished Pigment: Process Differences Between Pigments and Dyes
The "branching of the road" for pigments and dyes mainly begins in the later stages of synthesis:
Although both involve reactions such as diazotization and coupling, pigment synthesis has more stringent requirements for crystal form and particle shape, as this directly affects the pigment's hue, hiding power, and coloring intensity.
While dye precursors can be ground and auxiliaries added, the "filter cake" after pigment synthesis must undergo a special pigmentation treatment, including:
- ◆ Controlling Crystal Form: Through specific solvents or heat treatment, pigment molecules are grown into specific stable crystal forms (such as the α and β crystal forms of phthalocyanine blue).
- ◆ Surface Treatment: Rosin, surfactants, etc., are added to coat the surface of pigment particles, preventing aggregation and improving dispersibility and rheological properties in inks or coatings.
- ◆ Ultra-fine Grinding: Finer than dye grinding, ensuring the pigment achieves ideal coloring results in the application medium.
Example: Production of Phthalocyanine Blue
Taking the widely used Phthalocyanine Blue as an example:
Phthalic anhydride, urea, and cuprous chloride.
These intermediates condense in organic solvents to produce crude copper phthalocyanine (already blue).
Crude copper phthalocyanine must undergo special treatments such as acid dissolution or salt milling to transform the originally large and agglomerated particles into nano-sized, specific crystal form of blue pigment before it can be used in the manufacture of automotive paints, inks, etc.
💡 Therefore, when you hear "pigment intermediates," you can understand it as "dye intermediates" specifically used to manufacture pigments, with subsequent processes focusing more on the specific application properties of the pigment — lightfastness, dispersion, and crystal form.