1. Introduction​

Yellow pigments play a crucial role in various industries such as painting, coatings, plastics, and more. Pigment Yellow 184, Chrome Yellow, and Cadmium Yellow are three commonly used yellow pigments, each with its own unique characteristics. Understanding their differences and performance advantages and disadvantages is essential for choosing the most suitable pigment for specific applications.​

2. Chemical Composition​

2.1 Pigment Yellow 184​

Pigment Yellow 184, also known as bismuth vanadate yellow, has a chemical composition of Bi/V/Mo/Oxide. It comes in two main types: vanadate bismuth (PY5184 - 1) with a red - phase yellow and molybdenum bismuth yellow (PY5184 - 2) with a green - phase yellow. It is a high - performance inorganic pigment.​

2.2 Chrome Yellow​

Chrome Yellow, or lead chrome yellow, mainly consists of PbCrO₄ or PbCrO₄/xPbSO₄ mixed crystal. Due to different manufacturing conditions and compositions, its color ranges from lemon - yellow to orange. The proportion of PbCrO₄ affects the color depth and properties of the pigment.​

2.3 Cadmium Yellow​

Cadmium Yellow has a chemical composition of CdS. It is a bright - colored inorganic pigment. Sometimes, it may also contain small amounts of other elements or compounds to adjust its performance, but CdS is the main coloring component.​

3. Performance Comparison​

3.1 Color and Hue​

• Pigment Yellow 184: It presents a very vivid and bright yellow color. The red - phase vanadate bismuth and green - phase molybdenum bismuth yellow provide different hue options, and its color saturation is high, approaching that of high - performance organic yellow pigments.​

• Chrome Yellow: Chrome Yellow can exhibit a range of colors from light lemon - yellow to deep orange - yellow. The lighter shades are relatively more transparent, while the darker ones are more opaque. However, over time, especially the lighter chromes, they may darken under certain conditions.​

• Cadmium Yellow: Cadmium Yellow has a very intense and pure yellow color. It is known for its high color purity and brightness, which can make it stand out in a color palette.​

3.2 Covering Power​

• Pigment Yellow 184: It has good covering power. When used in combination with organic pigments, it can create a very bright luster, providing high - tonality and strong covering ability. It can effectively cover the substrate and prevent the underlying color from showing through.​

• Chrome Yellow: Chrome Yellow generally has excellent covering power. As the content of PbCrO₄ increases, the darker the color, the better the coverage. It can provide a strong and opaque film, which is very suitable for applications where good hiding power is required.​

• Cadmium Yellow: Cadmium Yellow has relatively good covering power, but it is usually less than that of Chrome Yellow. It can still provide a certain degree of opacity, but in some cases where high - hiding power is crucial, Chrome Yellow or Pigment Yellow 184 may be more preferred.​

3.3 Lightfastness​

• Pigment Yellow 184: Pigment Yellow 184 has excellent lightfastness. It can maintain its color stability under long - term sunlight exposure without significant fading. This makes it suitable for outdoor applications and products that need to maintain color for a long time.​

• Chrome Yellow: The lightfastness of Chrome Yellow varies with its color depth. The darker shades are more light - stable, while the lighter ones, especially lemon - chrome yellow, may darken or fade under light, especially ultraviolet light. This limits its use in some applications where high - level lightfastness is required.​

• Cadmium Yellow: Cadmium Yellow has very good lightfastness. It can resist fading under sunlight for a long time, making it a popular choice for artists' paints and high - quality coatings that are exposed to light.​

3.4 Chemical Resistance​

• Pigment Yellow 184: It has outstanding chemical resistance. It is resistant to acids, alkalis, various chemical solvents, and sulfur dioxide. It does not bleed or migrate, which means it can maintain its color and position in different chemical environments. This property makes it suitable for use in industrial coatings, chemical - resistant paints, and products in harsh chemical environments.​

• Chrome Yellow: Chrome Yellow is not very resistant to some chemicals. It will react with H₂S to form black PbS, which is toxic. It also turns into orange - chrome yellow when it meets alkali, so it should not be used with alkaline pigments. In addition, lead compounds in Chrome Yellow can accelerate the drying of dry oil, which may affect the performance of some coatings.​

• Cadmium Yellow: Cadmium Yellow is resistant to heat and alkali. However, it is acid - resistant, which means it may react with acidic substances, and its performance may be affected in acidic environments.​

3.5 Toxicity​

• Pigment Yellow 184: Pigment Yellow 184 is a high - environmental - performance inorganic pigment. It is non - toxic, which makes it suitable for applications in food - contact materials, toys, and other areas where safety is crucial.​

• Chrome Yellow: Chrome Yellow contains lead, which is toxic. The use of Chrome Yellow has been restricted in many countries and regions due to its potential harm to human health and the environment. Its production and application need to comply with strict safety regulations.​

• Cadmium Yellow: Cadmium Yellow contains cadmium, which is also a toxic heavy metal. Similar to Chrome Yellow, its use has been limited in some applications due to environmental and health concerns.​

3.6 Cost​

• Pigment Yellow 184: As a relatively new high - performance pigment, the production process of Pigment Yellow 184 may be more complex, and its cost is generally higher than some traditional pigments. However, its excellent performance can justify the cost in applications where high - quality and long - lasting color is required.​

• Chrome Yellow: Although Chrome Yellow was once widely used, due to its toxicity and the increasing cost of meeting environmental regulations, its production and use have decreased. In the current market, its cost may be relatively low in some regions where it is still available, but considering the potential environmental and health risks, the overall cost of using it may be higher in the long run.​

• Cadmium Yellow: Cadmium Yellow is relatively expensive. The scarcity of cadmium resources and the complexity of the production process contribute to its high cost. This limits its use to some high - end applications where cost is not the primary consideration.​

4. Applications​

4.1 Pigment Yellow 184​

• Automotive Coatings: Its high color fastness, chemical resistance, and bright color make it suitable for automotive exterior coatings, which need to withstand harsh environmental conditions and maintain a good appearance for a long time.​

• Powder Coatings: Pigment Yellow 184 can be well - dispersed in powder coatings, providing excellent color and durability. It is used in applications such as metal furniture coatings, architectural coatings, and industrial equipment coatings.​

• Plastics: It can be used to color various plastics, especially those used in outdoor applications or products that require high - level color stability. For example, it can be used in plastic building materials, outdoor plastic furniture, and automotive interior plastics.​

• Food - Contact Materials: Due to its non - toxic nature, Pigment Yellow 184 can be used in coloring plastics or coatings that come into contact with food, such as food packaging materials.​

4.2 Chrome Yellow​

• Traditional Artistic Painting (Limited): In the past, Chrome Yellow was widely used in artistic painting due to its good covering power and color range. However, due to its toxicity, its use in modern artistic painting has been greatly reduced. Some artists may still use it in a very limited way, but they need to take strict safety precautions.​

• Industrial Coatings (Limited): In some industrial coatings where the requirements for toxicity are not as strict and cost - effectiveness is considered, Chrome Yellow may still be used in small amounts. But with the increasing emphasis on environmental protection, its use is gradually being phased out.​

4.3 Cadmium Yellow​

• Artists' Paints: Cadmium Yellow is highly valued by artists for its bright and stable color. It is often used in oil paints, watercolors, and acrylic paints to create vivid yellow hues.​

• High - Quality Coatings: In some high - quality coatings, such as coatings for luxury goods, fine - art reproductions, and high - end decorative coatings, Cadmium Yellow is used to provide a long - lasting and brilliant yellow color.​

5. Conclusion​

In summary, Pigment Yellow 184, Chrome Yellow, and Cadmium Yellow have significant differences in chemical composition, performance, toxicity, and cost. Pigment Yellow 184 offers excellent performance in terms of color, lightfastness, chemical resistance, and environmental friendliness, making it suitable for a wide range of high - end applications. Chrome Yellow, although it has good covering power and color range, is limited by its toxicity and poor chemical resistance in modern applications. Cadmium Yellow, with its bright color and good lightfastness, is expensive and also has toxicity concerns, mainly used in high - end artistic and coating applications. When choosing a yellow pigment, one needs to comprehensively consider factors such as application requirements, cost, and environmental and health impacts to make the most appropriate choice.​