Direct Dyes Disperse Dyes Reactive Dyes and Catinonic Dyestuff

• CAS No.: 3180-81-2
• Formula: C16h17cln4o3
• EINECS: 221-668-1
• Model NO.: Direct blend dyes
• Colour: Red, Blue, Yellow, Black, Orange, Violet, Brown, Green
• Usage: Textile, Paint, Paper, Plastic, Ink, Leather
• Type: SE/M
• Application Material: Wool
• Name: Direct Dyes
• Content: 100%
• C.I.No.: Disperse Red 60
• Transport Package: Carton for Export Package
• Specification: Please find the below product details
• Trademark: Chinese Brands or OEM
• Origin: China
• HS Code: 3204110000
• Production Capacity: 30, 000 Metric Tons Per Year

Product Description

Products Introduction

Direct dyes are textile pigments that can dye fabrics through boiling in neutral or weakly alkaline environments without requiring mordants. These dyes rely on hydrogen bonding and van der Waals forces with cotton fibers, finding applications in textiles, silk production, cotton processing, leather manufacturing, and even papermaking. Structurally, they are categorized into types like azo dyes and divinylbenzene dyes.

By application, they are classified into three main groups: general direct dyes, direct lightfast dyes, and direct azo dyes.

Direct dyeing principle: Direct dyes contain water-soluble groups such as sulfonic acid groups (-SO3H) or carboxyl groups (-COOH), with molecules arranged in a linear structure. The aromatic ring structures are aligned in the same plane, giving direct dyes strong affinity for cellulose fibers. In neutral media, dyeing can be performed simply by dissolving the dye in water before application. The dye is adsorbed on the surface of the fiber in the solution, and then continuously diffuses to the amorphous region of the fiber, forming hydrogen bond and van der Waals force binding with the fiber macromolecules. The derived dyes include direct sun-dye and direct copper salt dye.

Dye Characteristics: Direct dyes contain water-soluble groups such as-SO3Na and-COONa, with their solubility increasing significantly with rising temperatures. For direct dyes with poor solubility, sodium carbonate can be added to enhance solubility. These dyes are not resistant to hard water, as most combine with calcium and magnesium ions to form insoluble precipitates, causing color spots on dyed fabrics. Therefore, soft water is essential for their dissolution. In production, if the dyeing water has high hardness, adding sodium carbonate or sodium hexametaphosphate can both improve dye solubility and soften the water. Direct dyes demonstrate superior direct dyeing performance on cellulose fibers compared to other dyes. This advantage stems from their larger molecular weight, linear molecular structure, enhanced symmetry, elongated conjugation system, and excellent planar alignment, which create strong van der Waals interactions between the dye and fiber molecules. Additionally, the presence of functional groups such as amino, hydroxyl, and azo in direct dyes enables hydrogen bonding formation with hydroxyl groups in cellulose fibers and amino/hydroxyl groups in protein fibers, thereby significantly enhancing the dye's direct dyeing efficiency. When direct dyes are applied to cellulose fibers, salts act as co-activators.

The mechanism involves direct dyes dissociating into pigment anions in solution to bind with cellulose fibers. Since cellulose fibers carry negative charges in water, an electrostatic repulsion occurs between dye and fiber. Adding salts reduces this repulsion, thereby enhancing both the dye uptake rate and dye uptake percentage. Different direct dyes exhibit varying effectiveness with salt co-activation. Dyes containing abundant sulfonic acid groups demonstrate significant salt-enhanced effects, requiring batch-wise salt addition during co-activation to ensure uniform dye distribution.

For direct dyes with lower uptake rates, increased salt dosage is necessary, with specific amounts determined by dye type and desired color depth. Light-colored products demanding uniform dyeing should use reduced salt levels to prevent uneven coverage and defects like mottling.

Temperature affects dye uptake performance differently across various dyes. Direct dyes with high uptake rates and good diffusion properties achieve maximum coloration at 60-70°C, while their uptake rate declines above 90°C. To shorten dyeing time, these dyes are typically processed at 80-90°C. During this period, as the dye bath temperature gradually decreases, residual dye continues to transfer onto fibers, enhancing uptake efficiency. For direct dyes with high aggregation tendency, slow uptake rates, and poor diffusion, elevated temperatures accelerate diffusion, improve uptake speed, and ensure complete dye absorption, thereby boosting uptake rates. The temperature achieving maximum uptake within standard processing time is termed the maximum uptake temperature. Based on this criterion, direct dyes are classified into three categories: low-temperature dyes (below 70°C), medium-temperature dyes (70-80°C), and high-temperature dyes (90-100°C). In industrial practice, cotton and viscose knits are dyed around 95°C, while silk knits require lower temperatures (60-90°C) due to concerns about excessive heat damaging fiber luster. Maintaining appropriate lower temperatures and extending processing time proves advantageous in production.

Common direct dyes

Direct blend dyes

No.			Depth o.w.f %	C.I.No.	Dyeing Fastness
					Light (Xenon)	Washing		Perspiration	Rubbing
	Name of Dyes	Color sample of cotton				40ºC	60ºC
						CH/CO/V	CH/CO/V	CH/CO/V	Dry/Wet
1	Direct Blend Brilliant D-GL		1.0	-	4	4 4-5 4	4-5 3-4 4-5	4-5 3-4 4-5	4-5 3-4
2	Direct Blend Yellow D-2RL		1.0	86	5	3-4 4 4-5	3-4 4 4	3 4-5 4-5	4-5 3
3	Direct Blend Yellow D-3RNL		1.0	161	4	3-4 4-5 4-5	3-4 4-5 4	3-4 4-5 4-5	4-5 4
4	Direct Blend Yellow D-ARL		1.0	106	5-6	4-5 4-5 4-5	4-5 4-5 4-5	4-5 4-5 4-5	4-5 4-5
5	Direct Blend Orange D-2GL		1.0	39	5	- - -	3-4 2-3 3	4-5 5 4-5	4-5 3-4
6	Direct Blend Orange D-5R		1.0	-	3-4	4 4 4	3-4 4-5 4-5	3-4 4-5 4-5	3-4 3
7	Direct Blend Scarlet D-GLN		2.0	-	3	4-5 4-5 4-5	4-5 4 2-3	3-4 4-5 4-5	4 3
8	Direct Blend Scarlet D-F2G		2.0	224	4	4 3 4	4 3 3	4 4 4	4 3
9	Direct Blend Brilliant Red D-FR		2.0	227	3-4	4 3 4	4 2 2-3	3-4 4-5 4-5	4-5 3-4
10	Direct Blend Rubine D-BLL		2.0	83:1	5-6	3-4 4 4-5	3 4 4-5	3-4 4-5 4-5	3 2-3
11	Direct Blend Violet D-5BL		2.0	66	4-5	3-4 4-5 4-5	4 4 4	3-4 4-5 4-5	4-5 3-4
12	Direct Blend Turquoise Blue D-BGL		2.0	-	4	4-5 4-5 4-5	4-5 4-5 4-5	4-5 4-5 4-5	4-5 5
13	Direct Blend Blue D-3GL		2.0	274	4-5	4-5 4-5 4	4-5 4 4	4 4-5 4-5	4-5 4-5
14	Direct Blend Blue D-RGL		2.0	70	4-5	3-4 4-5 4-5	3-4 3-4 4-5	3-4 4-5 4-5	4 2-3
15	Direct Blend Navy D-R		2.0	297	3-4	4-5 4 4-5	- - -	4-5 4-5 4-5	4-5 2-3
16	Direct Blend Brown D-RS		2.0	-	3	3-4 4 4-5	3 4 4-5	3-4 4 4-5	4-5 4
17	Direct Blend Gray D-B		2.0	-	3-4	3-4 3-4 4-5	4-5 3 3-4	4-5 4-5 4-5	4-5 3-4
18	Direct Blend Black D-HR		5.0	173	3-4	3-4 4-5 4-5	3-4 4 4	4 4-5 4-5	3 2
19	Direct Blend Black D-RSN		5.0	-	3-4	3-4 4-5 4-5	- - -	3 4-5 4-5	4 3
20	Direct Blend Black D-OB		5.0	80	3	3-4	- - -	- - -	- -

Dyeing Process:
1. Dyeing of T/C or T/R
Dyeing process of the disperse & D type direct blend dye in one bath in one step:

2. Dyeing process of cotton textile:

Remarks:
1. Levelling agent: Dosage of leimibang A (or detergent 613)(g/L)
Pale: 1.5-2g/L;
Medium: 1-1.5g/L;
Heavy: 0.5-1g/L;
(Pingpingjia is used as levelling agent, but the dosage is reduced by 1/2. However, it is best that the levelling agent is added in before the dyestuff is added in, so as to ensure the evenness of dyeing.
2. Accelerating agent: Dosage of glauber's salt (Na₂SO₄)(g/L)
Pale: 2-5g/L;
Medium: 5-10g/L;
Heavy: 10-20g/L;
(It is better that the accelerating agent is added in the halfway of dyeing, so as to prevent motted apperarance which is caused by higher initial dyeing rate. Sometimes, salt can be used, but the dosage can be reduced by 1/2-1/3.)
3. Color fixing
After dyeing, the loose color on fabric must be thoroughly cleaned away. Color fixing with alkalinity should be avoided.
Color fixing agent 0-4%(o.w.f)
Bath ratio 1:10-20,50ºC×20min
The proper ph value is 6(using HAC to adjust), which is useful for prevent dye agglomerated, so as to improve color fixing effect.
 

We are one of the most major dyestuff producers in China, the quality of our products could be guaranteed. 

Part of Our Customers

Company Introduction
Suzhou Trillion Shine Import & Export Co.,Ltd (Trillion Shine) is a leading Chinese supplier of dyestuff, and we also provide services for sourcing all related products of dyestuff industry from China, we have been involving in the dyestuff industry since 2003.

Relying on Chinese complete industry Chain and enjoying price advantages, we provide customers with premium products, reasonable prices,and on-time services.  Trillion Shine has a professional technique team who has been in this industry for more than 22 years, consists of advanced mechanics, engineers and professors. Powerful technical capabilities extend our core competence to analysis of customer's demand and provide customer with satisfying service.  

Trillion Shine has already established business relations with customers from South America, North America, Europe, Middle East, Southeast Asia and South Asia, obtained the customer affirmation and faith. The good faith manner,the premium quality product, the exquisite service and the customer first principle are Trillion Shine's service objective. Trillion Shine sincerely wish to establish stable business relationship with customers all over the world, please feel free to contact with us.