Introduction of fluorescent brightener OB-1(Optical brightener agent OB-1)

CI：393

CAS：1533-45-5

Chemical name: stilbene dibenzoxazole

Molecular formula: c28h18n2o2

Molecular weight: 414.4547

Properties: bright yellow green crystalline powder, insoluble in water, odorless, stable performance, melting point 355 ℃ - 360℃

Technical conditions:

Color light: blue light or blue violet light

Maximum absorption spectral wavelength: 374nm, with strong fluorescence and emission wavelength of 434nm

Content: ≥ 98.5%

Fineness: ≥ 300 mesh

UV absorption: ≥ 2000

Volatile matter: ≤ 1%

Ash content: ≤ 1%

OB-1 scope of application:

• Fluorescent brightener OB-1 is applicable to the whitening of polyester fiber, nylon fiber, polypropylene fiber and other chemical fibers.

• It is suitable for whitening and brightening polypropylene plastics, hard PVC, ABS, EVA, polystyrene, polycarbonate, etc.

• It is suitable for adding in the conventional polymerization of polyester and nylon.

• It is especially suitable for whitening plastic products formed at high temperature.

  
  

Introduction to OB-1 features:

1. With high temperature resistance, it is the fluorescent whitening agent for plastics with the widest application range and the largest sales so far. The public lover in the whitening agent is especially large in industries such as building materials, chemical fiber and polyester staple fiber.

2. Excessive use has poor weather resistance and easy precipitation, and the addition amount shall not exceed the peak value.

3. High fluorescence intensity, suitable for compounding with other models to produce synergistic effect.

   
   

Dosage of OB-1 method:

1. PVC and PP recycled materials are powerful whitening tools. The addition amount of profile is about 230g per ton, the granulation of general recycled materials is about 500-700g, and the chemical fiber plant is about 450g per ton.

2. Whitening and brightening of polypropylene plastics, rigid PVC, ABS, EVA, polystyrene, polycarbonate, etc

3. The addition proportion shall be determined according to the old and new raw materials.

4. The addition amount of color masterbatch is between 3kg and 10kg per ton.

5. The whitening agent OB-1 is equivalent to 0.01-0.05% of the weight of plastic or polyester particles, and can be fully mixed with materials before molding and processing of various plastic products or polyester fiber drawing.

   

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   Optical Brightener OB-1 Dosage in Different Plastics

   Plastic Type	Processing Temperature (°C)	Recommended Dosage (%)	Main Applications	Key Considerations
   Polyolefins (PE, PP)	180–240	0.01–0.05	Films, injection molding, fibers	High crystallinity materials require attention to dispersion; avoid high-temperature interactions with antioxidants causing yellowing.
   Polyesters (PET, PBT)	250–280	0.005–0.03	Fibers, bottle-grade PET, engineering plastics	Lower dosage for fibers (0.005–0.02%); avoid prolonged processing due to thermal decomposition.
   Polyamides (PA6/PA66)	260–290	0.01–0.04	Fibers, engineering plastics	Control humidity for hygroscopic materials; avoid contact with metal ions (e.g., Mg²⁺, Ca²⁺).
   Polycarbonate (PC)	280–320	0.005–0.02	Optical components, electronic housings	Strict dosage control to prevent thermal degradation; may reduce toughness—optimize via small-scale trials.
   ABS	200–240	0.01–0.05	Automotive parts, appliance housings	Test compatibility with flame retardants and lubricants; ensure uniform dispersion in thick-walled products.
   PVC	160–200	0.01–0.03	Pipes, films, artificial leather	Prevent additive migration by controlling temperature; avoid lead-based stabilizers.
   Polystyrene (PS)	180–220	0.01–0.03	Transparent packaging, stationery	Ensure dispersion in high-impact PS (HIPS); test stability with flame retardants.

   Supplementary Notes

   General Considerations:

1. Thermal Stability: OB-1 degrades at temperatures above ~300°C; adjust dosage for high-temperature processes.

2. Dispersion: Ensure thorough mixing in high-viscosity materials (e.g., PC, PA) to avoid localized overheating or yellowing.

3. Synergistic Effects: Combine with titanium dioxide or other brighteners for enhanced performance.

4. Safety/Compliance: Meets RoHS and REACH standards; avoid contact with strong oxidizers.

6. Application Tips:

1. Start with mid-range dosages (e.g., 0.02–0.03%) and adjust based on whiteness results.

2. Conduct long-term aging tests (light exposure, humidity) to validate durability.

3. Consult supplier technical data sheets (TDS) for product-specific recommendations.