ACID DYES MANUFACTURER IN INDIA

Sigmajet Technology Acid dyes manufacturer in Ahmedabad,Gujarat, India  and exporter in Global Market  are anionic, soluble in water and are essentially applied from acidic bath. These dyes possess acidic groups, such as SO3H and COOH and are applied on wool, silk and nylon when ionic bond is established between protonated –NH2 group of fibre and acid group of dye. Overall wash fastness is poor although light fastness is quite good. As dye and fibre contain opposite electrical nature, strike rate and uptake of acid dye on these fibres is faster; electrolyte at higher concentration is added to retard dye uptake and to form levelled shades. Acid generates cation on fibre and temperature helps to substitute negative part of acid with anionic dye molecules.

An acid dye is a dye that is typically applied to a textile at low pH. They are mainly used to dye wool, not cotton fabrics. Some acid dyes are used as food colorants, and some can also be used to stain organelles in the medical field.

Acid dyes Manufacturers affix to fibers by hydrogen bonding, Van der Waals forcesand ionic bonding. While some acid dyes work in water, many choose to activate dyes in acid dye-baths instead. According to the Brønsted–Lowry acid–base theory, an acid is a molecule or ion capable of donating a proton, and this is determined by the acid dissociation constant. Compared to most acids, water has a much higher pKa value, meaning that it dissociates to give H+ with more difficulty. In this context, if an acid is used instead of water, then the hydrogen ion (H+) is more easily able to dissociate in order to react with the aniline dye anion, allowing the dye to dissolve.

Animal protein fibers and the synthetic fiber nylon contain many cationic sites that bind anionic dye. The strength (fastness) of this bond reflects the strength of this ionic interaction.
Acidic dyes Manufacturers can be classified according to their dyeing behaviour. This includes their wet fastness, migration ability, and dyeing pH

• Leveling acid dyes: These dyes have relatively low molecular weights. Consequently they bmigrate more readily before fixation and they exhibit low wet fastness. They are not normally suited for use as apparel fabric. They require an acidic dyebath, often using sulfuric acid and sodium sulfate mixtures (pH2-4) together with leveling agents such as ethoxylated fatty amines.
• Milling dyes: These dyes arre high molecule weight, with the result that migrate slowly. Consequently they exhibit wet fastness, which is useful for dyeing wool materials. Milling acid dyes are sometimes called 'Neutral acid dyes' as they do not require an acidic dyebath. They are commonly applied using Acetic acid (pH4-7)
• Metal complex acid dyes: These dyes are composed of acid dye molecules complexed with a metal ion, which will usually be chromium or cobalt. Metal complex acid dyes have high molecular weightss, giving them low mobility and the high wet fastness. Due to this, they are commonly used on nylon and synthetic poly-amide fibers. Metal complex acid dyes are economical, however they produce relatively dull shades. Metal complex acid dyes take a larger range of pH in the dyebath (pH2-7)

SHADE	PRODUCT NAME	CAS NO.
	ACID YELLOW - 17	6359-98-4
	ACID YELLOW - 79	12220-70-1
	ACID RED - 127	61724-32-1
	ACID RED - 249	6416-66-6
	ACID RED - 357	61951-36-8
	ACID RED - 361	61931-22-4
	ACID RED - 447	141880-36-6
	ACID ORANGE - 33	6507-77-3
	ACID ORANGE - 94	61724-28-5
	ACID BLUE - 90	6104-58-1
	ACID BLUE - 185	12234-64-9
	ACID BLUE - 225	12216-97-6
	ACID BLUE - 260	62168-86-9
	ACID GREEN - 28	12217-14-8
	ACID BLACK - 172	57693-14-8
	ACID BLACK - 194	61847-02-0