Beer’s Law and UV Protection: The Innovation of Chiguard^® R-455

Why is Chiguard^® R-455 a superior choice for UV protection materials? The answer lies in the application of Beer’s Law, a key principle in UV coating design.

Optimizing UV Protection with Beer’s Law Beer’s Law defines the relationship between light absorption, substance concentration, and light path length. This allows formulators to design UV-resistant coatings with precision. 

The formula is as follows: A = ϵ⋅c⋅l

•    A: Absorbance – the amount of light absorbed by the material.
•    ϵ: Molar absorption coefficient – a material-specific constant.
•    c: Concentration of the UV absorber.
•    l: Light path length, such as material thickness.

Key Parameters for Control:
1.    Concentration (c):
By adjusting the concentration of Chiguard^® R-455, you can enhance or reduce UV protection. Higher concentrations lead to greater UV absorption, making the material ideal for applications requiring robust protection, such as outdoor use.
2.    Light Path Length (l):
Increasing material thickness improves UV absorption, offering an additional layer of defense for products exposed to prolonged UV exposure.

What Makes Chiguard^® R-455 Stand Out?

•    Embedded Protection: Unlike traditional UV absorbers, Chiguard^® R-455 becomes part of the polymer structure through chain extension, providing long-term stability and enhanced UV protection.
•    Predictable Design: Beer’s Law enables precise formulation, allowing designers to create long-lasting UV protection.
•    Industry-Recognized Innovation: Chiguard^® R-455’s breakthrough performance earned the 2023 Product Innovation Award from the Taiwan Chemical Industry Association (TCIA), highlighting its powerful potential in UV protection.
 

Long-lasting UV Protection Technology Embedded in Polymer Main Chains: Chiguard^® R-455

Chiguard^® R-455 is a reactive benzotriazole UV absorber developed by Chitec Technology, designed for high-efficiency UV protection in polyurethane products. R-455 features a primary diol structure that chemically crosslinks with hardeners such as isocyanates, amine resins, and organosiloxanes, embedding securely into the polymer main chain to provide long-lasting and stable UV protection.
Unlike traditional UV absorbers, R-455 is resistant to migration from within the material to the surface or extraction by solvents, significantly enhancing the product's weather resistance and lifespan. Even under UV exposure, temperature changes, or solvent effects, R-455 maintains its long-term UV protection.

Chemical Structure of Primary Diol Reactive Functional Group

R-455 contains a primary diol reactive functional group with two key characteristics:

1. High Reactivity: The primary diol structure in R-455 has high reactivity. The hydroxyl group (-OH functional group) can react with a variety of hardeners, forming strong covalent bonds that integrate R-455 into the polymer main chain.
2. Chemical Crosslinking Reaction: During polymer manufacturing, the primary diol functional group in R-455 chemically crosslinks with hardeners, embedding the UV absorber molecules securely into the polymer structure and forming irreversible chemical bonds.
    

Advantages of Embedding into the Polymer Main Chain

• Durability: The covalent bond structure formed by the chemical crosslinking reaction is highly stable, ensuring that R-455 remains embedded in the polymer main chain for long-term UV protection.
• Prevention of Migration: Since R-455 becomes part of the polymer, it addresses the issue of traditional additive-type UV absorbers migrating to the surface or being extracted by solvents, thus enhancing the product's weather resistance and stability.
• Consistency: Once embedded in the polymer main chain, the UV absorber is evenly distributed within the material, providing consistent and comprehensive protection.

Comparison with General UV Absorbers

General UV absorbers are typically dispersed in the polymer matrix through physical blending, which has the following drawbacks:

1. Migration and Loss: Over time, common UV absorbers may migrate, decompose, or be lost due to light, heat, or chemical reactions, leading to a gradual decline in protection.
2. Blooming: Blooming, or frosting, is a phenomenon that occurs on the surface of polymer materials. Certain additives (such as UV absorbers, antioxidants, plasticizers, etc.) migrate from within the polymer to the surface, forming a mist-like or crystalline layer. This results in a white or gray frost-like appearance that affects the material’s aesthetics and performance. Physically blended UV absorbers, lacking chemical bond support, are easily influenced by external conditions such as temperature, humidity, and light exposure, resulting in unstable protection.
    

Experience the Future of UV Protection Chiguard^® R-455 represents a new frontier in UV absorption technology, offering unrivaled performance for coatings and plastics. 

📨For more details or inquiries, please contact our sales team at sales@chitec.com.