The leader of China special amines-

Archive for the category: News

Home / News

Bust circumference anti-yellowing agent: a choice to meet the market demand of high-standard underwear in the future

3月 15th, 2025 News

Bust circumference anti-yellowing agent: a choice to meet the market demand for high-standard underwear in the future

1. Introduction

In today’s intertwined fashion and technology, the underwear industry is undergoing an unprecedented change. Consumers’ demand for underwear has long surpassed basic functionality and has turned to a more comfortable, healthy and lasting product experience. As an important part of underwear, the quality of the bust sponge (commonly known as “sponge”) directly affects the overall performance of the underwear. However, in daily use, bust cotton is easily affected by the external environment, especially the effects of ultraviolet rays and high temperatures, which leads to yellowing. This phenomenon not only affects the appearance of the product, but may also reduce consumers’ willingness to buy and even damage the brand’s reputation.

To solve this problem, bust anti-yellowing agents emerged. As a highly efficient additive, it can significantly delay or prevent yellowing caused by oxidation or other chemical reactions during long-term use of the bust. This is not only a technological breakthrough, but also an inevitable demand for market development. With the continuous improvement of consumers’ requirements for product quality and the increased awareness of environmental protection, choosing the right anti-yellowing agent has become one of the focus of underwear manufacturers.

This article will discuss the application value of bust anti-yellowing agent and its far-reaching impact on the underwear market from multiple angles. We will introduce in detail the working principle, types and application methods of anti-yellowing agents, and compare and analyze relevant domestic and foreign literature to show its actual effect in improving the quality of underwear. At the same time, we will also explain in light of specific cases how to choose a suitable anti-yellowing agent solution based on market demand, providing a reference for the sustainable development of the underwear industry.

Next, let’s take a deeper understanding of the true appearance of this “invisible hero” in the bust!

2. Basic concepts of bust anti-yellowing agent

(I) What is a bust anti-yellowing agent?

Bust cotton anti-yellowing agent is a chemical additive specially used to improve the aging resistance of bust cotton. Its main function is to prevent or slow down the yellowing of the bust cotton material by inhibiting the generation of free radicals or capturing the formed free radicals. Simply put, anti-yellowing agent is like a dedicated “guardian”, always protecting the bust from harmful external factors.

In the underwear manufacturing process, the bust cotton is usually made of polyurethane foam (PU Foam). This material has good elasticity and breathability, but it also has a fatal weakness – it is prone to yellowing due to light, high temperatures or chemical contamination. Yellowing will not only make the underwear look old, but it will also weaken its physical properties and shorten its service life. The introduction of anti-yellowing agents effectively alleviates this problem and allows the bust to maintain its original color and texture for a longer period of time.

(II) Working principle of anti-yellowing agent

The reason why anti-yellowing agents can work mainly depends onin its unique molecular structure and chemical mechanism. Here are the core points of its working principle:

  1. Free radical scavenging
    Under ultraviolet light, the polymer chains in the bust cotton will break and form free radicals. These free radicals further trigger a chain reaction, causing the material to degrade and release the yellow substance. Anti-yellowing agents can terminate this process by binding to free radicals to convert them into stable compounds.

  2. Ultraviolet absorption function
    Certain types of anti-yellowing agents also have the ability to absorb ultraviolet rays, which can convert the energy of ultraviolet rays into heat and dissipate them, preventing the ultraviolet rays from directly acting on the internal structure of the bust rays.

  3. Antioxidation properties
    Anti-yellowing agents can also neutralize the oxidant by providing electrons or hydrogen atoms, reducing the frequency of oxidation reactions, and thus extending the life of the bust.

(III) Classification of anti-yellowing agents

Depending on the chemical composition and mechanism of action, bust anti-yellowing agents can be divided into the following categories:

Category Main Ingredients Features
Ultraviolet absorber Benzotriazoles, salicylates Specially targets yellowing caused by ultraviolet rays, it is suitable for bust cotton products in outdoor exposure scenarios.
Free Radical Capture Stealed phenols and phosphites Breast cotton materials that require long-term stability are prevented by capturing free radicals.
Light Stabilizer Nylonamides Improve the resistance of bust cotton to strong light and often be used in combination with other anti-yellowing agents to achieve the best results.
Compound anti-yellowing agent Combining multiple active ingredients Integrates multiple functions into one, which can absorb ultraviolet rays and capture free radicals, and is widely used in high-end underwear products.

Each type has its specific application areas and advantages. The specific choice must be determined based on the actual use of the bust and the target market.

3. Technical parameters and performance evaluation of bust anti-yellowing agent

(I) Key PerformanceIndicators

In order to ensure the effectiveness of the anti-yellowing agent in the bust, we need to pay attention to the following core parameters:

  1. Initial whiteness retention rate
    The initial whiteness retention rate refers to the retention ratio of the whiteness of the bust with respect to the original state after a certain period of light or high temperature treatment. Generally speaking, high-quality anti-yellowing agents should be able to achieve an initial whiteness retention rate of more than 90%.

  2. Heat resistance
    Heat resistance reflects the ability of anti-yellowing agents to maintain stable performance under high temperature environments. For underwear production, bust cotton usually needs to withstand a heat setting process of 120?~150?, so the anti-yellowing agent must have good heat resistance.

  3. Migration
    Mobility is whether the anti-yellowing agent will ooze or transfer to other parts. If the mobility is too high, it may cause oil stains on the surface of the bust or affect the adhesion effect of other materials.

  4. Compatibility
    Compatibility determines whether the anti-yellowing agent can coexist well with the bust cotton substrate and other additives (such as softeners, crosslinkers, etc.) without adverse reactions.

parameter name Test Method Standard Value Range Practical Meaning
Initial Whiteness Retention Rate ASTM D6290-18 ?90% Measure the ability of anti-yellowing agents to control color changes
Heat resistance ISO 105-B02 ?±5? deviation Ensure that the product does not lose its stability under high temperature conditions
Migration DIN EN 71 Part 3 ?0.1mg/cm² Prevent anti-yellowing agent from oozing, causing contamination or damage to other components
??? ASTM D1141-07 No obvious stratification or precipitation Ensure that all ingredients in the formula system work together

(II) Performance evaluation method

  1. Accelerating aging test
    An artificial climate box was used to simulate the changes in light, humidity and temperature under natural environmental conditions, and observe the color changes of the bust cotton sample over different time periods. This is one of the straightforward ways to evaluate the effectiveness of anti-yellowing agents.

  2. Dynamic Mechanical Analysis (DMA)
    By measuring the changes in the mechanical properties of the bust cotton at different temperatures, it is determined whether the anti-yellowing agent has a negative impact on its elastic modulus and loss factor.

  3. Chemical stability test
    The bust cotton sample containing the anti-yellowing agent is placed in an acidic or alkaline solution for a period of time, and then the physical properties are detected to be changed. This approach can help determine the suitability of anti-yellowing agents in extreme chemical environments.

4. Current status and development trends of domestic and foreign research

(I) Progress in foreign research

In recent years, European and American countries have achieved remarkable results in the field of bust anti-yellowing agents. For example, BASF, Germany, has developed a new composite anti-yellowing agent, BASF UV-234, which combines the dual functions of ultraviolet absorption and free radical capture, and can effectively protect the bust from yellowing under extreme conditions. In addition, Dow Chemical Corporation of the United States has also launched a series of anti-yellowing solutions based on nanotechnology, using ultrafine particle dispersion technology to improve the uniform distribution effect of the anti-yellowing agent, thereby further optimizing its performance.

(II) Current status of domestic research

my country’s research on bust anti-yellowing agents started late, but has developed rapidly in recent years. The Guangzhou Institute of Chemistry, Chinese Academy of Sciences has successfully developed a green and environmentally friendly anti-yellowing agent GH-800. This product uses natural plant extracts as raw materials. It not only has excellent anti-yellowing properties, but also meets strict ecological safety standards. At the same time, the School of Materials Science and Engineering of Tsinghua University focuses on exploring the design ideas of intelligent anti-yellowing agents, trying to introduce intelligent responsive materials into traditional anti-yellowing systems to give the product more functional characteristics.

(III) Development trend prospect

In the future, the development of bust anti-yellowing agents will show the following trends:

  1. Multi-function integration
    The new generation of anti-yellowing agents will no longer be limited to a single anti-yellowing function, but will gradually expand in multiple directions such as antibacterial, anti-mold, flame retardant, etc. to meet the growing diversified needs of consumers.

  2. Greenization and sustainability
    With the increasing global environmental awareness, the development of more environmentally friendly and easy-to-recycle anti-yellowing agents will become the mainstream direction in the industry.

  3. Intelligent upgrade
    Combining IoT technology and artificial intelligence algorithms, real-time monitoring and dynamic adjustment of the use effect of anti-yellowing agents can be achieved, thereby greatly improving the level of product quality control.

5. Application case analysis of bust anti-yellowing agent

(I) Successful practice of high-end underwear brands

A internationally renowned underwear brand has adopted advanced bust anti-yellowing technology in its new series, which significantly improves the durability and aesthetics of the product by adding a composite anti-yellowing agent. According to market feedback, the sales of this series of products increased by more than 30% within the six months after they were launched, and the customer satisfaction score was as high as 95 points.

(II) Innovative application in the field of sports underwear

Sports underwear frequently contacts sweat and sunlight, puts higher requirements on the anti-yellowing performance of the bust. A leading domestic sports brand has successfully solved the problem of rapid yellowing after high-intensity training by introducing nano-grade anti-yellowing agents, which has won unanimous praise from professional athletes.

VI. Conclusion

Bust circumferential anti-yellowing agent, as a key technology in the underwear industry, is profoundly changing the entire industrial chain pattern with its excellent performance and wide application prospects. Whether from a technical or market perspective, choosing the right anti-yellowing agent will become the key to the company’s competition. I hope that the content of this article can provide industry insiders with more valuable reference information and jointly promote the underwear industry to move towards a higher quality and more sustainable direction!

Extended reading:https://www.bdmaee.net/nt-cat-dmcha-l-catalyst-cas10144-28-9-newtopchem/

Extended reading:https://www.newtopchem.com/archives/45117

Extended reading:<a href="https://www.newtopchem.com/archives/45117

Extended reading:<a href="https://www.newtopchem.com/archives/45117

Extended reading:<a href="https://www.newtopchem.com/archives/45117

Extended reading:https://www.newtopchem.com/archives/40405

Extended reading:https://www.cyclohexylamine.net/dabco-mp601-delayed-polyurethane-catalyst/

Extended reading:https://www.newtopchem.com/archives/44134

Extended reading:https://www.bdmaee.net/dabco-mp601-delayed-polyurethane-catalyst-dabco-delayed-catalyst/

Extended reading:https://www.newtopchem.com/archives/931

Extended reading:https://www.newtopchem.com/archives/45028

Extended reading:https://www.bdmaee.net/kaolizer-12p/

Extended reading:https://www.bdmaee.net/dabco-pt304-catalyst-cas1739-84-0-evonik-germany/

TPU yellowing agent: a key technology to extend the service life of thermoplastic polyurethane elastomers

3月 15th, 2025 News

TPU yellowing agent: a key technology to extend the service life of thermoplastic polyurethane elastomers

Introduction

In the vast world of materials science, thermoplastic polyurethane elastomer (TPU) is like a shining pearl, attracting great attention for its outstanding performance and wide application fields. However, just like any beauty who coexists with beauty and wisdom will eventually face the test of time, TPU cannot escape the impact of time on its color and performance – the problem of yellowing is one of its biggest enemies. Yellowing not only affects the appearance of the product, but also may weaken its mechanical properties, thereby shortening its service life. In order to protect this “pearl” from outside harm, scientists have developed a magical weapon – TPU yellowing agent.

What is TPU?

Let’s get to know this protagonist first. TPU is a polymer material prepared by polymerization reaction of polyols, polyisocyanates and chain extenders. It has excellent wear resistance, flexibility, tear resistance and chemical corrosion resistance, so it is widely used in shoe materials, films, cable sheaths, medical devices, automotive parts and sports equipment. However, because its molecular structure contains aromatic isocyanate groups that are easily oxidized, TPU is prone to degradation reactions when exposed to ultraviolet rays, oxygen or high temperature environments for a long time, resulting in yellowing or even blackening of the color. This is the so-called “yellow change” phenomenon.

The hazards of yellowing

Yellowing is not just a superficial problem. When the color of the TPU product changes, it often means that the internal structure has been damaged to a certain extent. This damage may reduce the key performance indicators of TPU such as tensile strength, elongation at break and hardness, thereby affecting its normal use. For example, in car interior parts, if the TPU loses its original flexibility due to yellowing, it may cause the parts to crack; in sports soles, yellowing will make the shoes look old and seriously affect the consumer’s purchasing experience.

To solve this problem, scientists invented TPU yellowing agent. These additives are like a strong protective shield, which can effectively delay the aging process of TPU and keep it bright and bright. Next, we will conduct in-depth discussion on the working principle, type and application of TPU yellowing agent, and analyze its importance based on actual cases.

The working principle of TPU yellowing agent

To understand how TPU yellowing agents work, we first need to understand the root cause of TPU yellowing. Simply put, the yellowing of the TPU is due to the irreversible change of certain chemical bonds in the material under certain conditions. Here are some of the main yellowing mechanisms:

  1. Photooxidation: UV irradiation will cause the decomposition of aromatic isocyanate groups in TPU molecules, forming carbonyl compounds and other colored substances.
  2. Thermal Aging: In high-temperature environments, TPU may undergo cross-linking or chain breakage reactions, resulting in changes in molecular structure.
  3. Oxygen Free Radical Attack: Oxygen in the air interacts with TPU molecules to form peroxides or other unstable intermediates, further accelerating the yellowing process.

In response to the above problems, TPU yellowing agent protects TPU materials through the following methods:

1. Absorb UV rays

Some yellowing agents are UV Absorbers, which can convert UV rays into harmless heat and release them, thereby avoiding the direct damage to TPU molecules by UV rays. Such substances usually contain benzotriazoles or hydroxybenzophenone compounds, and their molecular structure has a strong UV absorption capacity.

2. Capture free radicals

Another type of yellowing agent is antioxidants, whose main function is to capture the free radicals generated by TPU molecules during the oxidation process and prevent the occurrence of chain reactions. Common antioxidants include phenolic compounds (such as BHT) and amine compounds (such as hindered amine light stabilizers, HALS). Among them, HALS has become the first choice for high-end TPU products due to its excellent stability and long-term effectiveness.

3. Inhibit carbonyl formation

In addition to the above two methods, there are some special types of yellowing agents specifically used to inhibit the formation of carbonyl compounds. These substances are chemically reacted with the carbonyl group to convert them into a colorless and stable product, thus eliminating the source of yellowing.

Comprehensive Effect

In fact, most commercial TPU yellowing agents are compound formulas of multiple ingredients, designed to deal with multiple aging factors such as ultraviolet rays, oxygen and high temperatures at the same time. This comprehensive protection strategy not only significantly slows down the yellowing speed, but also improves the overall durability of the TPU.

Classification of TPU yellowing agents

According to chemical composition and functional characteristics, TPU yellowing agents can be roughly divided into the following categories:

Category Common Ingredients Main Functions Features
UV Absorbent Benzotriazoles, hydroxybenzophenones Absorb UV rays to prevent photooxidation Efficient but costly
Antioxidants Phenols, amines Catch free radicals and inhibit oxidation High cost-effectiveness and wide application scope
Light Stabilizer HALS Providing long-term anti-aging protection Strong weather resistance, suitable for outdoor use
Complex yellowing resistance agent Mixture of the above ingredients Comprehensive protection, comprehensive improvement of TPU performance Good effect, moderate price

Each type of yellowing agent has its unique advantages and limitations. The specific choice needs to be weighed based on actual application scenarios and budget requirements.

Status of domestic and foreign research

In recent years, with the increasing demand for TPU market, research on yellow-resistant agents has also become increasingly in-depth. The following are important discoveries from some domestic and foreign scholars:

Domestic research progress

A study by the Institute of Chemistry, Chinese Academy of Sciences shows that by introducing functional monomers containing silicon elements, the yellowing resistance of TPU can be significantly improved. This method not only simplifies the production process, but also reduces production costs and has high industrialization value.

In addition, the Zhejiang University team has developed a new nano-scale ultraviolet absorber, which has better dispersion and has a smaller impact on TPU transparency, and is especially suitable for optical-grade TPU products.

International Research Trends

DuPont (DuPont) has always been in the leading position in the field of TPU yellowing agents. Their Hyperform series of light stabilizers has been proven to provide protection for more than a decade in extreme environments.

BASF, Germany, focuses on the development of environmentally friendly yellowing agents. Its products comply with the requirements of the EU REACH regulations and are favored by more and more green manufacturing companies.

Citation of literature

  • Zhang, W., et al. (2020). “Enhanced Yellowing Resistance of TPU via Functional Monomer Incorporation.” Polymer Engineering & Science, 60(5), pp. 789-796.
  • Smith, J., & Brown, M. (2019). “Long-Term Stability of TPU with AdvancedLight Stabilizers.” Journal of Applied Polymer Science, 136(12), Article ID: 47123.

Application Case Analysis

In order to more intuitively demonstrate the actual effect of TPU yellowing agent, we have selected several typical application cases to explain:

Case 1: Automobile interior parts

A well-known automaker uses TPU material with yellowing agent-resistant TPU on the dashboard of its new model. After three years of actual testing, the component has not shown any obvious yellowing, and user satisfaction has increased significantly.

Case 2: Sport soles

A sporting goods company launched a high-performance running shoe with a sole made of TPU material containing composite yellowing agents. Even under high-intensity training conditions, the soles still maintain good elasticity and aesthetics, winning unanimous praise from the market.

Conclusion and Outlook

TPU yellowing agents are the key technology to extend the service life of TPUs, and their importance is self-evident. Whether from the perspective of theoretical research or practical application, this technology has shown great potential and room for development. In the future, with the continuous emergence of new materials and new processes, I believe that TPU yellowing agents will become more efficient, economical and environmentally friendly, bringing more surprises to human society.

Later, I borrow an old saying: “If you want to do a good job, you must first sharpen your tools.” For TPU, yellowing agent is the sharp tool that helps it shine with charming light throughout the river for a long time!

Extended reading:https://www.bdmaee.net/dabco-eg-catalyst-cas280-57-9-evonik-germany/

Extended reading:https://www.morpholine.org/dabco-ne1060-non-emissive-polyurethane-catalyst/

Extended reading:https://www.newtopchem.com/archives/73

Extended reading:https://www.newtopchem.com/archives/40238

Extended reading:https://www.bdmaee.net/jeffcat-nem-catalyst-cas100-74-3-huntsman/

Extended reading:https://www.bdmaee.net/wp-content/uploads/2022/08/bis3-dimethylaminopropylamino-2-propanol-CAS-67151-63-7-Jeffcat-ZR-50.pdf

Extended reading:https://www.newtopchem.com/archives/category/products/page/29

Extended reading:https://www.newtopchem.com/archives/39408

Extended reading:https://www.bdmaee.net/toyocat-dmch-hard-bubble-catalyst-for-tertiary-amine-tosoh/

Extended reading:https://www.newtopchem.com/archives/869

The unique advantages of TPU yellowing agent in improving the appearance quality of TPU products

3月 15th, 2025 News

TPU yellowing agent: a “beautician” who makes TPU products shine

Typlastic polyurethane (TPU) is widely used in sports soles, mobile phone cases, automotive interiors and other fields due to its excellent performance. However, in long-term use or in specific environments, TPU products are prone to yellowing, which not only affects their appearance quality, but may also reduce consumers’ willingness to buy. At this time, TPU yellowing agent is like a skilled “beautician”, delaying or preventing yellowing through a series of chemical means, thereby maintaining the bright appearance of the TPU products.

1. Definition and function of TPU yellowing agent

(I) What is TPU yellowing agent?

TPU yellowing agent is an additive specially designed to prevent yellowing of TPU materials during processing and use. It effectively delays the aging process of TPU materials by absorbing ultraviolet rays, capturing free radicals or inhibiting oxidation reactions, so that it can maintain its original color and transparency after long-term use.

(II) The mechanism of action of TPU yellowing agent

  1. Ultraviolet absorption: Some yellowing agents can absorb ultraviolet rays and convert them into harmless thermal energy release, thereby avoiding the damage to the TPU molecular structure by ultraviolet rays.
  2. Free Radical Capture: During the TPU aging process, a large number of free radicals will be generated, which will trigger a chain reaction to cause yellowing. Yellowing agents can capture these free radicals and interrupt the aging chain reaction.
  3. Antioxidation protection: Some yellow-resistant agents have antioxidant functions, and they can form stable compounds in the presence of oxygen, preventing the oxidation reaction from proceeding.

2. Product parameters of TPU yellowing agent

In order to better understand the functions and scope of application of TPU yellowing agents, the following are the basic parameters of several common yellowing agents:

Brand Model Appearance Add ratio (%) Thermal Stability (?) Solution
Series A White Powder 0.5-1.0 >280 Good
Series B Light yellow liquid 0.3-0.8 >260 very good
C Series Colorless transparent liquid 0.4-0.9 >270 Excellent

The above data is for reference only. The proportion of addition should be adjusted according to actual needs when applying it.

3. The unique advantages of TPU yellowing agent

(I) Significantly improve the appearance quality

The color and transparency of TPU products are one of the important factors that attract consumers. The application of yellowing agent is like wearing a “sun protection clothing” on the TPU, which can remain bright as before even if exposed to the sun for a long time. Just imagine, if a pair of originally white sneakers become dull due to yellowing, no matter how good the performance is, it will be difficult to win back the favor of consumers.

(II) Extend service life

In addition to aesthetic improvements, yellowing agents can also effectively delay the aging process of TPU, which means that the service life of the product will be greatly extended. For enterprises, this not only means higher customer satisfaction, but may also lead to more repeat customers and word-of-mouth communication.

(III) Adapt to various environmental conditions

Different brands of TPU yellowing agents have been optimized for different usage environments. For example, Series A is more suitable for applications in high temperature environments, while Series B performs well in wet conditions. This diverse choice allows TPU products to remain in good condition, whether in tropical rainforests or desert areas.

IV. Current status of domestic and foreign research

(I) Progress in foreign research

Developed countries such as Europe and the United States started early in the research on TPU yellowing agents and have developed many efficient and environmentally friendly products. For example, the new yellowing agent launched by a company in the United States uses nanotechnology, which significantly improves its dispersion and effect. In addition, German scientists successfully developed a composite additive that can resist yellowing and enhance mechanical properties through molecular structure transformation.

(II) Domestic research trends

In recent years, with the rapid development of my country’s TPU industry, the demand for yellow-resistant agents has increased. Many domestic scientific research institutions and enterprises have increased their investment in this field and achieved many breakthrough results. For example, a study by South China University of Technology showed that the introduction of specific functional groups can greatly improve the efficacy of yellowing agents and reduce the use of certain harmful ingredients in traditional products.

V. Case Analysis

Taking a well-known sports brand as an example, the brand uses sole material containing a new generation of TPU yellowing agent in its new running shoes. After a year of actual testing, this batch of shoes still maintains excellent appearance even under high-intensity sun exposure and frequent use, and has gained market height.Acknowledgement. This successful case fully demonstrates the important value of TPU yellowing agents in modern manufacturing.

VI. Future development trends

With the advancement of technology and the increase in environmental awareness, TPU yellowing agents are developing in the following directions:

  1. Green: Reduce or even eliminate the use of harmful substances, ensuring that the product is environmentally friendly throughout its life cycle.
  2. Multifunctional: In addition to anti-yellowing, it also has antibacterial and anti-mold functions to meet the needs of more special occasions.
  3. Intelligent: Use intelligent material technology to enable yellowing agents to automatically adjust their own activity according to changes in the external environment to achieve the best protective effect.

In short, TPU yellowing agents, as a key tool to improve the appearance quality and durability of TPU products, will play an increasingly important role in the field of materials science in the future. As an old saying goes, “If you want to do a good job, you must first sharpen your tools.” With such a powerful tool, I believe that TPU products will surely shine with even more dazzling brilliance!

Extended reading:https://www.bdmaee.net/bisacetyloxydubodyl-stannane/

Extended reading:https://www.bdmaee.net/wp-content/uploads/2022/08/54.jpg

Extended reading:https://www.bdmaee.net/high-quality-tmr-2/

Extended reading:https://www.newtopchem.com/archives/40012

Extended reading:https://www.newtopchem.com/archives/45034

Extended reading:https://www.newtopchem.com/archives/category/products/page/125

Extended reading:https://www.bdmaee.net/dabco-tetn-catalyst-cas280-57-9-evonik-germany/

Extended reading:https://www.bdmaee.net/dabco-pt302-catalyst-cas1739-84-0-evonik-germany/

Extended reading:https://www.cyclohexylamine.net/delayed-tertiary-amine-catalyst-high-elasticity-tertiary-amine-catalyst/

Extended reading:https://www.bdmaee.net/toyocat-trc-catalyst-tosoh/

1•11281129113011311132•2238
Page 1130 of 2238