Azoic Dyes

Nylon Dye Tracid Violet 4BNS Acid Violet 17

Acid Dye Acid Red G Acid Red 1

Nylon Dye Acid Orange Ⅱ Acid Orange 7

Fabric Dye Tracid Dark Blue 5R Acid Blue 113

Wool Dye Tracid Brilliant Blue 6B Acid Blue 83

Iron Oxide Pigments for concrete and cement bricks coloring

High Quality Fabric Dye Powder Direct Red 227

Factory Direct Supply Eco-friendly Textile Dye – Direct Red 224

Cost-Effective General Dye – Direct Red 28

High Strength Direct Red 13

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Azoic Dyes With High Wash Fastness

1. Core Principle of Azoic Dyes: "Synthesizing" dyes on fibers.

2. Main Applications: Azoic Dye is used in Cotton, linen, and other cellulosic fibers.

3. Typical Process: Base coat + color development (low-temperature ice bath).

4. Best Advantages: Vibrant colors, wash and lightfast, low cost.

5. Main Disadvantages: Relatively low rubbing fastness.

product details

Product Description

Azoic Dyes (also called insoluble azo dyes) are a very unique type of dye. Their special feature is that the dye is not a pre-made product, but rather "synthesized" directly on the fiber during the dyeing process.

Below is a detailed breakdown of this magical dye that is "born and grown" on the fiber:

What are Azoic Dyes?

Azoic Dyes are water-insoluble azo dyes produced through a chemical reaction (coupling reaction) on the fiber from two intermediates: naphthol and chromophore.

The Origin of Name Its name, "Azoic Dyes" comes from its core process: before dyeing, one of the components (chromophore) needs to be treated at low temperature (usually with ice cooling) to generate a reactive diazonium salt, hence the name.

Why is it called "Azoic Dyes"? (Process characteristics)

This name directly comes from its dyeing process:

Base treatment:

First, the fabric is treated with an alkaline solution of naphthol (allowing the fibers to absorb the naphthol).

Low-temperature preparation:

Another component, the color base, undergoes diazotization. This process must be carried out using ice cooling, maintaining a low temperature of approximately 0-5°C, because the resulting diazonium salt will decompose and become ineffective at high temperatures.

Color development (conducted in an ice bath):

The fabric treated with chromophore is immersed in a cold diazonium salt solution. Inside the fibers, the two components meet and instantly combine, generating a vibrant pigment.

Because it relies on low temperatures (ice) and dyeing, it is aptly named "Azoic Dyes" in Chinese.

Understanding Azoic Dyes Performance

To understand this more intuitively, you can think of it as a precise chemical reaction occurring inside the fabric. This unique mechanism also determines its core advantages and disadvantages:

Color Performance:

Vibrant colors, complete color spectrum. It can dye very rich reds, oranges, deep blues, and even blacks, especially bright reds and maroons, which are unmatched by other dyes.

Color Fastness:

Wash and light fastness. Because the final product is a water-insoluble dye, the wash fastness is excellent (rating 4-5). Simultaneously, the light (sunlight) fastness is also very good (rating 6-7), and the color is long-lasting and does not fade.

Process Cost:

Low price and simple process. The synthetic raw materials are simple and the cost is low. Although it requires two steps, the process itself is not complicated.

Core Pain Point:

Low rubbing fastness. This is its most significant drawback. Because the dye is generated on the fiber surface, some dye particles may be large, resulting in poor rubbing fastness (especially wet rubbing) and easy color fading. This needs to be improved through thorough soaping after dyeing.

Fiber Compatibility:

Specifically designed for cotton fibers. Primarily used for dyeing and printing cellulose fibers such as cotton and linen, it is commonly found in handicrafts. It can also be used with vinylon, viscose, and other fibers.

Commercial Forms: Developed for Ease of Use

Due to the instability of diazonium salts in the color base, dye manufacturers have developed more stable commercial forms for easier use:

Fast Pigment:

A mixture of naphthol and trans-diazo salt, it develops color after printing via acid treatment.

Fast Sulfonate:

A mixture of naphthol and diazonium sulfonate, offering even better stability.

Fast Amine:

A mixture of naphthol and diazonium amino compounds, exhibiting excellent stability and being the most convenient to use.

Azoic Dyes, with their unique formation process and excellent color performance, still hold a place in the dyeing of cotton fabrics, especially in dark and bright red colors.