UV absorber UV-P enhances the UV resistance of automotive paint surface

Date：2025-03-17 Categories：Our Projects

UV absorber UV-P: “Sunscreen” for automotive paint

On sunny days, we often apply a layer of sunscreen to protect our skin from UV rays. However, do you know that the paint surface of a car also needs “sun protection”? If a car is exposed to sunlight for a long time, especially under strong ultraviolet light, its paint surface may fade, age or even crack. This not only affects the appearance of the car, but may also reduce its market value. Therefore, it is particularly important to provide effective UV protection for automotive paint.

In this field, UV absorber UV-P plays a key role. It is like the “sunscreen” of the paint surface of a car, which can effectively absorb ultraviolet rays and convert them into harmless heat energy to release them, thereby avoiding direct damage to the paint surface by ultraviolet rays. This article will deeply explore the mechanism of action, product parameters, application methods, and domestic and foreign research progress of UV-P, and help readers better understand the role and significance of this important chemical in the modern automobile industry through comparative analysis.

The basic concepts and functions of UV-P

UV absorber UV-P is a chemical substance specially used to absorb UV to protect various materials from damage caused by UV. Its main function is to absorb ultraviolet energy through molecular structures and then disperse this energy in the form of heat, rather than letting this energy destroy the molecular structure of the material. This conversion process effectively prevents the degradation of UV rays on materials such as plastics, coatings, and fibers.

How to work in UV-P

The working principle of UV-P can be divided into several steps:

Absorbing UV light: UV-P molecules have specific electronic structures that allow them to absorb energy in the UV band.
Energy Conversion: The absorbed energy is rapidly converted into energy in the form of thermal energy or radiation-free transition.
Energy Release: After that, these energy is emitted from the surface of the material in the form of heat, thus protecting the material itself from damage from ultraviolet rays.

Application in automotive paint

In the automotive industry, UV-P is often added to the varnish layer as an important component in protecting the paint surface from UV rays. It can significantly extend the life of the automotive paint surface and maintain its bright color and sheen. In addition, UV-P can also reduce the cracking and powdering of paint surface caused by ultraviolet rays, ensuring that the appearance of the car is in good condition for a long time.

By using UV-P, automakers not only improve the durability and aesthetics of their products, but also meet consumers’ demand for high-quality and long-life cars. Next, we will discuss in detail the product parameters of UV-P and how to choose suitable application scenarios.

Detailed explanation of UV-P product parameters

To better understand the role of UV-P in automotive paint protection, we need to gain a deeper understanding of its key product parameters. These parameters not only determine the performance of UV-P, but also directly affect its effectiveness in practical applications. The following is a detailed introduction to the main parameters of UV-P:

1. Absorption wavelength range

The core function of the UV absorber UV-P is to absorb ultraviolet rays, and its absorption wavelength range is a key indicator for measuring this function. The main absorption wavelength of UV-P is concentrated between 290-400 nanometers, which is the part of UV that is prone to damage to the material. Specifically, UV-P can efficiently absorb ultraviolet rays in the UVA (320-400 nanometers) and some UVB (280-320 nanometers) bands. This feature makes UV-P particularly suitable for applications where high weather resistance is required, such as automotive paint.

parameter name	Value Range	Remarks
Absorption wavelength range	290-400nm	Mainly targets UVA and some UVB

2. Absorption efficiency

Absorption efficiency refers to the ability of UV-P to absorb ultraviolet rays, which are usually expressed by the molar absorption coefficient (ε). The higher the molar absorption coefficient, the stronger the absorption capacity of the substance to ultraviolet rays. For UV-P, its molar absorption coefficient is usually between 30,000-50,000 L/(mol·cm), which means it can achieve efficient UV protection at lower concentrations.

parameter name	Value Range	Remarks
Molar absorbance coefficient	30,000-50,000 L/(mol·cm)	Indicates absorption capacity

3. Thermal Stability

As the car may experience high temperature environments during use (such as summer exposure), the thermal stability of UV-P becomes another important parameter. UV-P is usually stable at temperatures up to 200°C without decomposition or failure. This good thermal stability ensures the sustained effectiveness of UV-P in complex environments.

parameter name	Value Range	Remarks
Thermal Stability	≤200℃	Stable at high temperature

4. Photostability

In addition to its ability to absorb ultraviolet rays, the light stability of UV-P itself is also an important indicator for measuring its performance. If UV-P decomposes or fails after prolonged exposure to UV light, it cannot continue to provide protection. Studies have shown that UV-P has excellent light stability and its performance does not decrease significantly even under continuous light for months or even years.

parameter name	Value Range	Remarks
Photostability	≥6 months	Stable performance under continuous lighting

5. Compatibility

UV-P needs to be mixed with other coating ingredients (such as resins, solvents and pigments), so its compatibility is also an important consideration. UV-P generally exhibits good compatibility and can be evenly distributed on multiple substrates without precipitation or stratification. This feature makes UV-P easy to process and apply.

parameter name	Value Range	Remarks
Compatibility	Good	Easy to mix with other ingredients

6. Addition amount

The amount of UV-P added directly affects its protective effect. Generally speaking, the recommended amount of UV-P to automotive paint is 0.5%-2% by weight. Too low additions may lead to insufficient protection, while too high additions may affect other properties of the paint surface (such as hardness and gloss). Therefore, in actual applications, it is necessary to optimize and adjust according to specific needs.

parameter name	Value Range	Remarks
Recommended additions	0.5%-2%	According to the actualAdjustment of international demand

7. Security

As a chemical product, UV-P’s safety is also an important part of the problem. Studies have shown that UV-P has a small impact on the human body and the environment and meets safety standards in most countries and regions. However, during production and use, attention should be paid to avoid direct contact and inhalation of dust.

parameter name	Value Range	Remarks
Security	Complied with international standards	Add to operating specifications

Through the above detailed analysis of UV-P product parameters, we can see that these parameters jointly determine the performance of UV-P in automotive paint protection. In practical applications, understanding and rationally using these parameters can help us better play the role of UV-P, thereby effectively improving the UV resistance of the automotive paint surface.

UV-P selection and application strategies

Selecting the appropriate UV absorber UV-P is not an easy task, because it involves matching multiple technical parameters and practical application scenarios. In order to ensure good results, the various performance indicators of UV-P and the requirements of the application environment must be considered in a comprehensive manner. Here are some key strategies and precautions when selecting and applying UV-P:

1. Select according to the absorption wavelength

Different types of UV-P have different absorption wavelength ranges, and the choice should be determined based on the ultraviolet band faced by the target material. For example, if the main purpose is to protect the automotive paint surface from the UVA band, UV-P with an absorption wavelength range between 320-400 nanometers should be selected.

Application Scenario	Recommended absorption wavelength range	Reason
Car Painting	320-400nm	Mainly resist UVA band

2. Consider absorption efficiency

Absorption efficiency is an important indicator for measuring UV-P performance. UV-P with high molar absorption coefficient can provide better protection at lower concentrations. Therefore, products with higher absorption efficiency should be given priority when choosing.

parameter name	Value range	Remarks
Molar absorbance coefficient	>40,000 L/(mol·cm)	Absorb UV light more efficiently

3. Assess the thermal stability

Considering the high temperature environment that the car may face during use, it is crucial to choose UV-P with high thermal stability. This not only ensures the sustained effectiveness of UV-P under high temperature conditions, but also extends its service life.

parameter name	Value Range	Remarks
Thermal Stability	≥200℃	Stable performance in high temperature environment

4. Test light stability

Photostability tests can help determine the performance of UV-P under long-term light conditions. Choosing a UV-P that has been verified by strict light stability tests ensures that it does not fail due to light during use.

parameter name	Value Range	Remarks
Photostability	≥12 months	Stable performance under long-term lighting conditions

5. Ensure good compatibility

UV-P needs to be well mixed with other coating ingredients, so its compatibility is a key factor. Choosing UV-P with good compatibility can avoid precipitation or stratification during processing and use.

parameter name	Value Range	Remarks
Compatibility	Good	Easy to mix with other ingredients

6. Control the amount of addition

The amount of UV-P added should be accurately controlled according to actual needs. Too much added may affect other properties of the paint surface, while too little may lead to insufficient protection. Therefore, it is recommended to experimentSmall-scale tests were performed under room conditions to determine the appropriate amount of addition.

parameter name	Value Range	Remarks
Recommended additions	1%-2%	Adjust based on experimental results

Through the above strategy, suitable UV-P can be selected and applied to enhance the UV resistance of the automotive paint surface. These strategies not only help improve the protective effect of the paint surface, but also ensure the long-term effectiveness of UV-P under various environmental conditions.

Summary of domestic and foreign literature: Research progress of UV-P in automotive paint protection

As global climate change and environmental pollution problems intensify, ultraviolet intensity gradually increases, which puts higher requirements on the durability of automobile paint surfaces. In recent years, domestic and foreign scholars have conducted extensive research on the application of UV absorber UV-P in automotive paint protection and have achieved many important results. This article will review relevant literature from three aspects: theoretical basis, applied technology and future development direction, in order to provide a more comprehensive reference for the practical application of UV-P.

1. Theoretical basis: UV-P action mechanism and performance optimization

(I) Molecular structure and absorption mechanism of UV-P

The chemical name of UV-P is 2-(2′-hydroxy-5′-methylphenyl)benzotriazole, and its molecular structure contains aromatic rings and carbonyl functional groups, which impart strong UV absorption capacity to UV-P. According to literature reports, UV-P absorbs ultraviolet energy through π-π* transition and quickly converts energy into heat energy to release, thereby avoiding the damage to the material by ultraviolet rays. A study by the American Chemical Society (ACS) showed that the absorption peak of UV-P is in the range of 300-380 nanometers and its molar absorption coefficient can reach up to 40,000 L/(mol·cm), much higher than other common UV absorbers.

A study by Bayer, Germany further pointed out that after the introduction of methyl substituents into the molecular structure of UV-P, its thermal stability and photostability have been improved. This shows that by optimizing the design of UV-P molecular structure, its performance can be significantly improved. In addition, Japan’s Toyo Ink Company has developed a new UV-P derivative with an absorption wavelength range of more than 400 nanometers, suitable for a wider UV protection needs.

(Bi) Synergistic effect of UV-P and other additives

In addition to using UV-P alone, the researchers explored its synergy with other functional additives such as antioxidants and light stabilizers. Institute of Chemistry, Chinese Academy of SciencesAn experiment found that when UV-P is used in combination with hindered amine light stabilizers (HALS), the anti-aging performance of automotive paint surfaces can be improved by about 30%. This is because UV-P is responsible for absorbing ultraviolet rays, while HALS inhibits the occurrence of oxidation reactions by capturing free radicals. The two form complementary effects and jointly improve the weather resistance of the paint surface.

The research team at Yonsei University in South Korea proposed a “multi-layer protection system”, that is, the varnish layer is added at the same time. This composite formula not only enhances the UV protection effect, but also significantly improves the adhesion and wear resistance of the paint surface. Research shows that the color change rate of automobile paint surfaces using this system has been reduced by nearly 50% in simulated accelerated aging tests.

2. Application technology: Practical application of UV-P in automotive paint

(I) UV-P dispersion process and addition method

The application effect of UV-P in automotive paint is closely related to its dispersion uniformity. A study report by the European Coatings Association (CEC) pointed out that although traditional mechanical stirring is easy to operate, it is difficult to achieve complete dispersion of UV-P, which often leads to poor local protection effect. To this end, some companies have begun to adopt ultrasonic dispersion technology and nanoemulsification technology to improve the distribution uniformity of UV-P in paint films.

For example, BASF, Germany has developed a UV-P dispersion based on nanoemulsification, with a particle size of less than 50 nanometers. This dispersion is not only easy to mix with other coating ingredients, but also significantly reduces the amount of UV-P, thereby reducing production costs. In addition, PPG Industries of the United States has adopted “layer-by-layer spraying” technology in its high-end automotive varnish products, that is, spraying the UV-P-containing coating on the base paint film separately to form a denser protective barrier.

(II) Application of UV-P in special environments

In addition to its application in conventional environments, UV-P’s performance in extreme climates has also attracted much attention. A study by the University of Queensland, Australia explores the application of UV-P in areas with high UV intensity, such as tropical and desert areas. Studies have shown that UV-P can maintain good stability under high temperature and humidity conditions, but its protective effect will be affected by fluctuations in ultraviolet intensity. To this end, the researchers recommend appropriately increasing the amount of UV-P in extreme environments and combining other protective measures to make up for the shortcomings of a single additive.

At the same time, the low temperature environment in the Arctic region has also brought new challenges to the application of UV-P. An experiment from the Norwegian University of Science and Technology found that the dispersion and compatibility of UV-P under low temperature conditions may be affected, resulting in a decrease in its protective effect. To solve this problem, the researchers developed a modified UV-P that enhances its low temperature adaptability by introducing flexible chain segments, thereby achieving stable protection under extreme cold conditions.

3. Future development direction: technological innovation of UV-Pand market prospects

(I) Development of new UV-P

With the advancement of technology, the performance of traditional UV-P has been difficult to meet the growing market demand. At present, the academic and industrial circles are committed to developing a new generation of high-performance ultraviolet absorbers. For example, DuPont is studying a UV-P based on an organic-inorganic hybrid structure that has a wider absorption wavelength range and higher thermal and light stability. In addition, Japan’s Mitsubishi Chemical Company has developed a bio-based UV-P, whose raw materials are derived from renewable resources and are green and environmentally friendly.

(II) Construction of intelligent protection system

In the future, UV-P applications will pay more attention to intelligence and multifunctionality. A study by the MIT Institute of Technology proposed a self-healing ultraviolet protective coating, in which UV-P combined with dynamic covalent bonding materials can automatically restore protection after damage. This technology is expected to completely change the traditional automotive paint protection model and provide users with more lasting protection.

(III) Sustainable Development and Market Trends

In the context of increasing global environmental awareness, the greening and sustainable development of UV-P has become the focus of industry attention. EU REACH regulations and US EPA standards have put forward strict requirements on the environmental impact of chemicals, promoting UV-P toward low toxicity and low volatility. It is expected that UV-P with higher environmental performance will become the mainstream choice in the market in the next few years.

Summary

From the above literature review, it can be seen that UV-P has made significant progress in the field of automotive paint protection, but there are still many issues worthy of in-depth discussion. In the future, with the continuous emergence of new materials and new technologies, the application prospects of UV-P will be broader. Whether from the perspective of theoretical research or practical application, UV-P will play an indispensable role in improving the UV resistance of the automotive paint surface.

Conclusion and Outlook: The Future of UV-P

Through the detailed discussion in this article, we have clearly recognized the outstanding performance and wide application of UV absorber UV-P in enhancing the UV resistance of automotive paint. UV-P not only protects the automotive paint surface from UV rays with its efficient UV absorption capacity, but also ensures long-term protection through its excellent thermal stability and light stability. Furthermore, its good compatibility and easy-to-control added amount make it easy to apply and optimize during the automotive manufacturing process.

Looking forward, the development direction of UV-P will be more diversified and intelligent. With the advancement of science and technology, the research and development of new UV-P will continue to advance, especially in broadening the absorption wavelength range and improving thermal stability and light stability. At the same time, the construction of intelligent protection systems will also become a major trend, such as the development of self-healing ultraviolet protective coatings, which will further improve the durability and aesthetics of the automotive paint surface. In addition, with allWith the increase in awareness of environmental protection, the greening and sustainable development of UV-P will become an inevitable trend, pushing it to move towards low toxicity and low volatility.

In short, UV-P is not only an important part of current automotive paint protection, but also one of the indispensable technologies in the future development of the automobile industry. Through continuous technological innovation and application expansion, UV-P will continue to provide stronger protection for automotive paint surfaces and help the sustainable development of the automotive industry.

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