Introduction of direct dyes

Direct dyestuffs account for most of the banned dyestuffs, so the development of environmentally friendly direct dyestuffs has become the focus of the dyestuff industry's new variety development in recent years. Specific varieties of direct dyes are as follows:　　

(1) Diaminostilbene Disulfonic Acid Direct Dyes: These dyes have bright color and moderate fastness, and Direct Sunlight Resistant Orange GGL (C.I. Direct Orange 39) is an environmentally friendly dye with better performance. Direct sunlight yellow 3BLL (C.I. Direct Yellow 106) is a triazole direct dye, with a sunlight fastness of 6 to 7. Direct sunlight green IRC (C.I. Direct Green 34) has high dyeing rate, excellent dyeing fastness, sunlight fastness up to grade 6 to 7, washing fastness up to grade 3 to 4.

(2) 4.4`-Diaminodiphenylurea direct dyes: these dyes are non-carcinogenic and have high sunlight fastness. There are many kinds of dyestuffs, which are environmentally friendly dyestuffs. Such as direct sunlight yellow RSC (C.I. direct yellow 50), direct sunlight red F3B (C.I. direct red 80), C.I. direct brown 112, C.I. direct brown 126, C.I. direct brown 152 and so on.

(3) 4.4`-Diaminobenzoyltiphenylamine type direct dyes: these dyes have better fastness and are environmentally friendly. Such as direct green N-B (C.I. direct green 89), direct yellow-brown N-D3G (C.I. direct brown 223), direct black N-BN (C.I. direct black 166) and so on.

(4)4.4`-Diaminobenzenesulfonyltiphenylamine type direct dyes: this kind of dyes is to synthesize black direct dyes with diamine compounds, and the dyeing **** ability and fastness are very good. It is widely used in the dyeing of cotton, linen, viscose fiber, silk and leather. Products have been developed and screened to replace the banned direct dyes, such as C.I. Direct Black 166 (Direct Black N-BN), C.I. Acid Black 210 (Acid Black NT), C.I. Acid Black 234 and so on.

(5) Diamino heterocyclic direct dyes: These dyes are direct dyes synthesized with diamino heterocyclic compounds, such as dibenzodioxazine direct dyes, which have bright color, high color strength and dyeing fastness, and sunlight fastness up to grade 7. The representative varieties are C.I. Direct Blue 106 (Direct Sunlight Resistant Brilliant Blue FF2GL), C.I. Direct Blue 108 (Direct Sunlight Resistant Blue FFRL) and so on.

(6) polyester/cotton (polyester/viscose) fabrics with environmentally friendly direct dyes: polyester/cotton, polyester/viscose blended fabrics and other different properties of the fibers in the same bath dyeing, which requires direct dyes with excellent high-temperature stability, with good lifting power and re-enactment of good fastness and environmental protection performance. Shanghai Dyestuff Company has developed direct blended D dyes, which are environmentally friendly dyes that can achieve the above properties, and now the varieties have reached more than 25, such as C.I. Direct Yellow 86 (Direct Blended Yellow D-R), C.I. Direct Yellow 106 (Direct Blended Yellow D-3RLL), C.I. 224 Direct Blended Big Red D-GLN, C.I. Direct Violet 66 (Direct Blended Violet D-5BL), C.I. Direct Blended Violet 66 (Direct Blended Violet D-5BL), C.I. Direct Blended Dye D-3RLL, and C.I.224 Direct Blended Violet D-5BL, and C.I.224 Direct Blended Violet D-5BL. C.I.Direct Blue 70 (Direct Blend Blue D-RGL), C.I.95 Direct Blend Brown D-RS, C.I.Direct Black 166 (Direct Blend Black D-ANBA) and so on. Individual varieties of these are copper complexes and the free copper should be within the limit value (250mg/kg) specified by ETAD.

(7) Japan Chemical & Pharmaceutical Company developed and screened Kayaeelon C-type dyes: C.I. direct yellow 161 (Yellow C-3RL), C.I. direct red 83 (Rubine C-BL), C.I. direct blue 288 (Blue C- BK), C.I. Direct Green 59 (Caeen C-CK), C.I. Direct Black 117 (Crey C-RL), and so on.

Hyundai Group of Thailand launched Modern Direct series of advanced direct dyes, Dystar developed Sirius Plus series of direct dyes, Ciba launched Cibafix ECO direct dyes, BASF launched Diazol series of direct dyes, and Yorkshire launched Benganil series of direct dyes. These dyestuffs have similar functions, such as bright color, high sunlight fastness, environmentally friendly dyestuffs without heavy metals, excellent high temperature stability, and are suitable for one-bath one-step dyeing of polyester/cotton blended fabrics.