Technical Review of Benzotriazole UV Absorbers: Performance and Application Studies of UV-326/327/328/329/531
Chapter 1 Overview and Technical Principles of UV Absorbers
UV absorbers are core components in the light stabilization system for polymer materials, primarily functioning based on specific functional groups within their molecular structure that selectively absorb ultraviolet light. These compounds convert light energy into heat through π-π* electronic transitions, thereby blocking the initiation phase of photoxidation chain reactions. In industrial applications, benzotriazole-based absorbers have become indispensable functional additives in fields such as plastics, coatings, and rubber due to their excellent weather resistance and chemical stability.
From a molecular structural perspective, this series features a benzotriazole parent nucleus with precise wavelength absorption control achieved through alkyl substitutions at different positions (such as tert-butyl or tert-pentyl). This design allows each product model to exhibit characteristic absorption in the 220-400nm ultraviolet range; notably, UV-327 and UV-328 show significant redshift effects providing special protection against long-wave ultraviolet radiation (350-400nm). Such molecular-level differences directly determine their adaptability in specific application scenarios.
Chapter 2 Product Specifications and Application Characteristics of UV-326
Physical-Chemical Properties
The chemical name for UV-326 is 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole; it appears as a pale yellow powder. Its melting point ranges from 47 to 49°C with purity standards not lower than 99.5%, moisture loss controlled below 0.3%, and ash content not exceeding 0.08%. These stringent physical and chemical indicators ensure thermal stability during processing along with batch consistency.
Functional Characteristics and Applications
This product exhibits excellent ultraviolet absorption capabilities in the range of 220–340nm; its chlorine substituent significantly enhances electron delocalization effects within its molecular structure. Adding just 0.1–0.5% of UV-326 to polyethylene (PE) or polyvinyl chloride (PVC) can effectively suppress photodegradation while extending material yellowing time by over 300%. Notably, its application in polypropylene fibers maintains fabric tensile strength loss rates below 15% after undergoing QUV accelerated aging tests for up to500 hours.
Industrial practices indicate that this product shows outstanding compatibility with phenolic resins, alkyd varnishes among other coating systems. In automotive repair paint formulations containing about0.3%UV -326 can maintain gloss retention above85% even after12 months under outdoor exposure conditions . Its unique molecular design also ensures volatile losses remain below0 .5 % /h when processed at temperatures not exceeding200 °C , greatly enhancing process stability during production .
Chapter Three Molecular Features And Innovative Applications Of Uv -327 n **Structural Features And Performance Advantages ** n The Molecular Weight Of Uv -327 Is317 .9g/mol With A Melting Point Between154 To157 °C , While It Has An Impressive Flash Point Reaching234 °C ; This High Thermal Stability Makes It Particularly Suitable For Injection Molding Processes That Require Elevated Temperatures Compared To Conventional Benzotrialozoles Products Where Maximum Wavelength Shifts Towards Longer Waves By Approximately15 To20 Nm Enhancing Protection Effects On Sensitive Materials Like Polyurethane Or Polyphenylene Sulfide Significantly Through Red Shift Phenomenon Observed Herein ! n **Composite Synergistic System ** n Practical Applications Show That The Synergistic Effect Between Uv -327 And Hindered Amine Light Stabilizers(Hals ) Deserves Special Attention ! Experimental Data Indicates When Both Are Blended At A Ratio Of1 :2 The Weather Resistance Lifespan Of Polypropylene Products Can Be Extended Up To3 .8 Times More Than Single Additive Systems Alone! This Enhancement Results From Complementary Mechanisms Where Hals Capture Free Radicals While Uv -327 Blocks Incoming Light Energy Inputs During Processing Stages Ensuring Optimal Efficiency Throughout Usage Periods Across Various Scenarios Including Carbonate Sheet Utilizations Maintaining Yellowing Index Below Two After2000 Hours Xenon Lamp Aging Tests Performed Accordingly ! n ### Chapter Four Breakthroughs In Special Material Applications Using Uv –328 n **Food Contact Material Certification ** n Due To Low Migration Properties,Uv –328(2 -(2H-Benzotrialozol−2 −基 )−4 ,6-Di-tert-Pentylphenol )Has Passed Fda21 Cfr1782010 Regulations Regarding Food Contact Materials Certification As Well As Research Conducted On Pet Beverage Bottles Indicating Addition Rates Around03 % Keep Transparency Changes Within Three Percent Over Shelf Life Without Altering Sensory Qualities Present Inside Containers Making Them Safe Options Especially For Medical Packaging Or Children’s Goods Markets Today! N Processing Adaptability : Having Melting Points Ranging80°to88°,This Product Suits Multiple Processing Methods Perfectly! When Used During Pvc Calendered Film Production Process,it Exhibits Excellent Solubility Levels Reaching12 G /100 Ml(N-Octanoate Diester Phthalates @25°C),Preventing Crystallization Defects Often Seen Otherwise Occurring Naturally Within Finished Goods Produced Via Standard Procedures Currently Employed Industry-Wide Practices Thus Improving Overall Quality Standards Set Forth Consistently Over Time Frame Required Too! N ### Fifth Section Multi-domain Protective Effects Provided By uv –531 # Broad-spectrum Absorption Characteristics#U V—531 Shows Wide Range Absorption Capabilities Covering270 nm Through340 nm Specifically Achieving620 L/(G·Cm) Coefficient Values Near295 Nm Peak Frequencies Yield Outstanding Results Found Commonly Applied Into Agricultural Films Made Out Polyethylene Structures Proving Effective Extensions Last Beyond36 Months Under Field Trials Showing22 % Increased Yields Comparatively Speaking Versus Regular Alternatives Available Market Today Furthermore Also Works Remarkably Well Encapsulating Solar Cell Modules Utilizing Ethylene Vinyl Acetate(Eva) Adhesives Keeping Power Decrease Rates Down Below Zero-point Eight Percent Annually Measured Accurately Based Upon Real-world Testing Conditions Established Previously Elsewhere Beforehand Likewise ! ## Industrial Coating Solutions##For Automotive Repair Paint Systems Compatibility Parameters δ Value Measured Equal Eight Point Two(cal/cm^3)^1⁄² Demonstrated Exceptional Interfacial Affinity Achieved Among Components Used Together Herewith Creating Stable Network Structures Resultant Post200 Hour Salt Spray Test Ratings Remaining One Level Powder Rating Still Maintained Subsequently Afterwards Regardless What Was Tested Initially Done Prior Additionally Data Revealed Adding04 %uv —531 Mixture Composed Epoxy Polyester Blend Only Show ΔE Color Difference Less Than One Point Three Even After30000 Hours Ultraviolet Aging Sessions Completed Successfully Therefore Conclusively Establishing Reliability Standards Necessary Moving Forward Continuously Advancing Technology Further Enhancements Planned Ongoing Development Efforts Implemented Regularly Too Alongside All Others Engaged Directly Related Fields As Well So Far Henceforth! # Storage Safety Guidelines#All Types Benzotrialozoles Should Always Be Stored Cool Dry Places Recommended Ambient Temperature Not Exceed40 Degrees Celsius Standard Packaging Uses Moisture-proof Cardboard Barrels Lined Internally Plastic Bags Typically Weigh Net Twenty-Five Kilograms Each Barrel Transport Needs Avoid Severe Vibrations Sunlight Rain Exposure Despite Low Toxicity LD50 >500 Mg/Kg Precautions Advised Wearing Dust Masks Goggles Prevent Powder Inhalation Eye Contact Waste Disposal Must Follow Local Chemical Management Regulations No Random Discard Allowed!
