Transparent Coating Guardian - NLS Light Stabilizer Anti-Yellowing Technology

No fear of harsh sunlight! Facing increasingly intense UV radiation and extreme environments, transparent coating products face unprecedented weatherability challenges. Everlight Chemical's newly launched liquid light stabilizer NLS provides a breakthrough solution for yellowing problems in silicone coatings, not only maintaining high transparency but also significantly extending service life - a key anti-aging solution for various optical and outdoor applications.

Why Do Transparent Materials Need Coating Protection?

Polycarbonate (PC) is a transparent plastic material widely used in everyday and high-end products. With high transparency, impact resistance, and heat resistance, it's commonly found in safety glasses, headlight covers, helmet visors, electronic screens, and even architectural skylights. Simply put, PC is the material of choice for products that need to be "both crystal clear and impact resistant".

However, PC has natural weaknesses - its surface is prone to scratching, abrasion, and yellowing after prolonged sun exposure. To extend service life and maintain appearance quality, manufacturers apply a transparent coating as a protective layer on PC surfaces. This coating must simultaneously provide transparency, hardness, and weather resistance to be truly effective.

One of the most commonly used coating materials in the industry is "silicone-modified coating", which combines scratch and weather resistance, widely applied in outdoor equipment, optical components, and industrial applications.

(Image source: Pixabay)

Yellowing: The Greatest Enemy of Transparent Coatings

Despite stable performance, silicone coatings still experience yellowing under prolonged UV exposure. This not only affects aesthetics but also reduces light transmittance by 30-40%, impacting optical precision and causing premature failure of high-value materials.

Yellowing is caused by free radicals generated when organic components in the coating are exposed to light, triggering a series of degradation reactions. Organic resins added to improve flexibility or processability often become the starting point for these reactions, gradually turning the originally crystal-clear coating into a "yellow-brown filter".

Figure 1: Transparent coating aging and yellowing comparison

NLS Light Stabilizer: Solving Yellowing While Maintaining Transparency

To solve the poor solubility and compatibility issues of existing light stabilizers in silicone coatings, Everlight Chemical's team developed the specialized liquid light stabilizer NLS. Traditional Triazine-type light stabilizers, while offering some anti-yellowing effect, tend to cause oil phase separation and cloudiness in silicone coatings during practical application, hindering film formation and optical quality. NLS, designed as a liquid combining UVA (UV absorber) and HALS (Hindered Amine Light Stabilizer), demonstrates excellent compatibility and stability - the solution remains clear and transparent without fogging, ensuring stable processing and performance.

Figure 2: Compatibility test comparison (5 phr addition)

Figure 3: NLS anti-yellowing test results

Simply put, NLS not only solves yellowing problems but also maintains the protective function of coatings, making it an indispensable light stabilization choice for high-performance transparent materials.

Everlight Chemical's Weatherability Solutions Supporting Every Critical Application

As transparent materials are increasingly applied in automotive lighting, medical devices, smart wearables, and other fields with higher appearance and performance requirements, coating weatherability and optical stability have become quality indicators that cannot be ignored. Particularly under long-term sun exposure and outdoor conditions, inhibiting yellowing and extending material service life have become important challenges for industrial upgrading.

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