Vat Blue RSN（Vat Blue 4）

1. Product Overview

Vat Blue RSN is a reddish-blue vat dye known for its outstanding wash and light fastness. It is widely applied in cotton, viscose, and denim dyeing for deep, long-lasting shades.

• CI Name & No.: Vat Blue 4

• CAS No.: 81-77-6

• Category: Vat dye

• Appearance: Reddish-blue powder

• Key Features: Brighter than sulphur dyes, more durable than direct dyes, higher chlorine & sunlight resistance than many reactive dyes

• Markets: Denim, uniforms, heavy-duty workwear, and casual wear

2. Technical Specifications

3. Performance & Fastness

• Wash fastness: 4–5 (ISO 105-C10)

• Light fastness: 6–7 (ISO 105-B02)

• Rubbing fastness: Dry 4 / Wet 3–4 (ISO 105-X12)

• Chlorine resistance: Better than reactive dyes, especially in deep shades

• Build-up: Excellent for deep navy and black tones

   Recommended Dyeing Conditions

• Medium: Alkaline vatting process

• Reducing agent: Sodium dithionite (Na₂S₂O₄)

• Temperature: 60–80 °C

• Oxidation: Air or hydrogen peroxide, followed by soaping

4. Applications

• Denim fabrics — the most widely used vat dye for deep indigo and black denim

• Cotton fabrics — yarn dyeing, woven & knitted cotton materials

• Viscose & rayon — level dyeing with excellent fastness

• Workwear & uniforms — resistant to repeated washing & sunlight

• Casual wear — T-shirts, trousers, jackets, fashion garments

• Industrial textiles — canvas, tents, heavy-duty fabrics

5. Quality & Compliance

• COA provided with every batch (Shade, Strength, Moisture, Insolubles, pH)

• APEO-free, complies with EU restricted azo dye regulations

• Heavy metals & formaldehyde controlled within international limits

• SDS available (English; other languages on request)

6. Packaging & Logistics

• Standard: 25 kg P.W. bag / fiber drum / carton box

• Bulk: 500–1000 kg jumbo bags available

• MOQ: 100 kg (trial order) / 1 MT (bulk)

• Delivery: 7–10 days from warehouse

• Shelf life: 24 months (dry, ventilated storage)

• Ports: Tianjin / Qingdao / Shanghai

7. Samples & Support

• Free laboratory samples (10–50 g) available

• Courier freight to be paid by customer (DHL/UPS account)

• Technical support: shade matching & process optimization

8. Related Products

• Sulphur Blue BRN (Sulphur Blue 7) – deep navy sulphur dye for cotton & denim

• Sulphur Black BR  (Sulphur Black 1) – popular sulphur dye for deep black shades

• Direct Fast Light Blue FFRL (Direct Blue 108) – direct dye for textile & paper