What is Optical Brightener OB-1?

📝Product Overview

Optical Brightener OB-1 (4,4'-Bis(2-benzoxazolyl)stilbene) is a high-performance benzoxazole fluorescent brightener. It absorbs ultraviolet light (wavelength range 340-370 nm, with a peak around 370 nm) and emitting bright blue fluorescence (wavelength range 420-470 nm, peak around 435 nm). This effectively neutralizes the yellow hue of substrates, significantly enhancing whiteness, brightness, and visual vividness.

Its molecular structure confers exceptional heat resistance (melting point 350-360°C, decomposition temperature >450°C) and broad polymer compatibility. Suitable for polyester (PET), polypropylene (PP), ABS, PVC, nylon, and other materials, it serves as an ideal whitening agent for plastics, fibers, coatings, and recycled materials, catering to both high-end and general-purpose applications.

🔬Key Specifications

CAS Number :1533-45-5

EC Number : 216-245-3

Molecular Formular : C28H18N2O2

Molecular Weight : 414.4547

English name :  Fluorescent Brightener 393

Appearance : bright yellow crystalline powder

Purity,% : ≥99%

Melting point,°C : 357-359°C

Volatile conten,% : ≤0.50%

Ash content,% : ≤0.10%

🚀Application Areas

1️⃣Plastics and Polymers

General-purpose plastics: Polypropylene (PP), Polyethylene (PE), Rigid PVC products (e.g., appliance housings, daily packaging, recycled PET bottle flakes).  

Engineering plastics: ABS, PC, PS, HIPS, Nylon (PA) (used in electronic components, automotive parts, injection-molded parts).  

Examples: Cosmetic bottles, food-grade PET containers, toys, furniture laminates, recycled polyester products. Recommended dosage: 20-300 ppm (depending on material).

2️⃣Paints and Coatings

Industrial Coatings: Metallic baked paints, high-gloss topcoats, coil coatings, architectural decorative coatings.  

Specialty Coatings: UV-curable coatings, fluorescent marking coatings, water-based or solvent-based dispersion systems. Recommended dosage: 0.01-0.1%, requires thorough dispersion.

3️⃣Synthetic Fibers

Melt whitening for polyester (PET), nylon (PA), and polypropylene (PP) fibers; nonwoven fabrics (e.g., PP nonwovens for medical or sanitary products). Recommended dosage: 75-300 ppm (polyester) or 75-200 ppm (nylon, PP fibers).

4️⃣Inks and Printing

Premium packaging inks (solvent-based, UV-curable inks), anti-counterfeiting printing materials, screen printing, and gravure printing (e.g., labels, decorative printing).

📦 Packaging and Storage

Packaging Specifications

Standard Packaging: 25 kg/drum (lined with aluminum foil bag, sealed moisture-proof)

Storage Conditions

Store in a cool, dry place away from light and sealed.

Recommended temperature: 10-30°C (50-86°F), relative humidity: ≤70%

Keep away from strong oxidizing agents, heat sources, and open flames.

Transportation and Safety

Non-hazardous material; suitable for standard logistics transport.

Wear dust masks and gloves during handling.

Shelf life:

 24 months