Overview
BLS® 3638 is a highly efficient benzoxazinone-type UV absorber that offers strong and broad UV absorption, especially in the UV-A region, with no color contribution, providing excellent stabilization for polyesters and polycarbonates.
Chemistry
Chemical Name: 2,2′-(1,4-Phenylene) bis [4H-3,1-benzoxazin-4-one]
CAS Number: 18600-59-4
Chemical Structure
Typical Properties
Product Form: Solid
Melting Range: 310 – 320oC
Molecular Weight: 368.3 g/mol
Applications
BLS® 3638 is designed for use in engineering plastics such as Nylon, PC, PET, PBT, and PPO, where it meets the high-temperature requirements and offers excellent stabilization. It is also effective in other polymers like polyamides, polyacetals, polyolefins, styrenics, and elastomers, providing long-term UV stability. The product is ideal for applications where light transmission and optical properties are critical, such as PET film, fibers, containers, PETG, PC capstock, and PC molding. Its strong UV-A absorption and low volatility ensure minimal loss of UV stability, even during the recycling or reworking of scrap materials.
Advantages
- Superior UV-A light absorption
- No color contribution to the polymer
- Excellent stabilization for engineering plastics
- Low volatility, even at high processing temperatures
- High heat stability, both short-term (up to 350°C) and long-term (up to 160°C)
- Effective for both indoor and outdoor applications
Guidelines for Use
Suggested use levels for BLS® 3638 are 0.1-10% by weight using conventional techniques such as powder blending, solution blending, or melt blending (e.g., extrusion compounding). It can be used alone or in combination with antioxidants, phosphites, and other light stabilizers to achieve synergistic performance. Typically, the dosage level for BLS® 3638 is about one-third of that required for benzotriazole-type UV absorbers to achieve similar UV screening efficiency in the UV-A region.
Storage
This product may be stored up to two years in a sealed container. Containers should be kept tightly closed when not in use and stored in a cool, dry place.
Safety
Please consult the Safety Data Sheet (SDS) prior to handling or using this product.
FDA Regulations
BLS® 3638 has not been cleared by the FDA for use in food contact applications.
