High Fastness Fabric Dyes Powder Direct Yellow 142
Basic Information
Product Name: Direct Yellow 142, Direct Fast Yellow PG, Direct Yellow PG
C.I. No.: Direct Yellow 142
CAS No.: 71902-08-4
Chemical Formula: C₃₁H₂₈N₁₀Na₂O₉S₂
Molecular Weight: 794.73
Product Description
Direct Yellow 142 (also known as Direct Fast Yellow PG) is a bis-azo direct dye with good light fastness. Bright brilliant-yellow shade can be obtained by single-bath dyeing. It features good levelness and is widely used for colouring cellulosic materials.
Physical & Chemical Properties
Appearance: Bright-yellow to golden-yellow homogeneous powder. Solubility: Freely soluble in water with good solubility at high temperature, aqueous solution shows brilliant yellow shade. Slightly soluble in ethanol; practically insoluble in other organic solvents. Acid-alkali reaction: Brownish-yellow colour in concentrated sulfuric acid, yellow precipitate after dilution. Yellowish-brown precipitate with concentrated hydrochloric acid; pale yellow-brown precipitate with concentrated sodium hydroxide. Metal influence: Copper and iron ions cause slight shade shift. Avoid copper-iron equipment in dyeing process.
Dyeing Properties
Good affinity for cellulosic fibres, optimum dyeing temperature 80-90℃. Good levelness. Suitable for exhaust dyeing, jig dyeing and pad dyeing. Generally not fit for discharge printing.
Main Application Fields
Textile industry: Mainly used for dyeing cellulosic fibres such as cotton, linen, viscose and jute; suitable for woven and knitted fabrics; also for some blended fabrics. Other industries: Widely applied for paper, leather dyeing, as well as ink and colour paste manufacturing. Colour mixing application: Can be used alone for brilliant-yellow shade, or blended with other direct dyes to produce composite colours such as green, brown and khaki.
Usage Method
Direct Yellow 142 is an economical yellow direct dye with good light fastness, mainly for cellulosic fibres like cotton, viscose and jute.
1. Key Dyeing Process Points
Dye characteristics: Good dye uptake and levelness. Neutral-weak alkaline dye bath, maximum affinity at 80-90℃. Moderate tolerance to hard water. Operation points: Raise temperature gradually, add sodium chloride or sodium sulphate in portions for exhaustion. Cool down step-wise after dyeing for better exhaustion and avoid uneven dyeing. Fastness improvement: Post-treatment with fixing agent is recommended to improve soaping fastness and wet rubbing fastness.
2. Application Scope
Textiles: Exhaust, jig & pad dyeing for cotton, linen, viscose and jute fabrics, not suitable for discharge printing. Other applications: Dyeing of paper and leather, preparation of colour paste and ink.
Direct Yellow 142 is a bis-azo direct dye featuring outstanding light fastness.
