Introduction: Understanding Black Pigment and Its Importance in Industry

Black Pigment Powder is produced through various methods.
Interestingly, among all black pigments, carbon-based pigments—commonly known as carbon black pigments or sometimes simply soot pigments—have maintained their superiority in the market. The majority of black pigment production and sales are attributed to these types.

Carbon black, which is the most common form of black pigment, is a vital industrial material used in a wide range of products—from automobile tires to newspaper printing inks. Chemically, it consists of extremely fine carbon particles (ranging from nanometers to micrometers), typically produced through the controlled thermal decomposition of hydrocarbons. Thanks to its unique properties, carbon black plays a crucial role in enhancing the performance and quality of many industrial products.

Chemical and Physical Structure of Carbon Black

Understanding the structure of carbon black is essential for grasping its properties and applications. Below is a closer look:
• Chemical Composition:
Carbon black typically contains 97–99% carbon and 1–3% trace elements such as oxygen, hydrogen, nitrogen, and sulfur. These minor components significantly affect the surface characteristics and reactivity of the material.
• Particle Structure:
Carbon black particles are generally spherical with diameters ranging from 10 to 500 nanometers. These primary particles tend to cluster together to form structures known as aggregates. The shape and size of these aggregates strongly influence the final properties of the pigment.
• Specific Surface Area (BET):
One of the key characteristics of carbon black is its specific surface area, measured in m²/g. This parameter indicates the available surface for interaction with other materials and typically ranges from 20 to 1500 m²/g. Higher surface area corresponds to stronger pigmentation and reinforcing abilities.
• Bulk Density:
The bulk density of carbon black ranges from 100 to 500 kg/m³, depending on the type and production method.

Production Methods of Black Pigment: From Traditional to Modern

There are several methods used to produce black pigment, each offering unique features and applications. Below are three main production methods for carbon black:

1. Furnace Black Process – The Most Advanced Method

Production Process:
• Injection of heavy oil into a high-temperature furnace (1400–1600 °C)
• Thermal decomposition in a low-oxygen environment
• Rapid quenching with water
• Particle separation using bag filters

Final Product Characteristics:
• Particle Size: 10–80 nm
• Specific Surface Area: 25–150 m²/g
• Yield: 40–60% of the raw material

Main Applications:
• Automotive tires (70% of global consumption)
• Engineering plastics
• Industrial coatings

The Furnace Black Process is recognized as the most advanced and widely used method for producing carbon black due to its high efficiency, precise control over particle size, and the ability to tailor the final product’s properties.

Channel Black Process – Traditional Method

Production Process :
• Incomplete combustion of natural gas
• Soot collection on cooled metal surfaces
• Mechanical separation of the carbon particles

Limitations:
• Low yield (5–15%)
• High environmental pollution
• Inconsistent product quality

Due to these limitations, the Channel Black process is rarely used in modern carbon black production.

Thermal Black Process – Suitable for Large Particles

Unique Characteristics :
• Particle Size: 200–500 nm
• Low Specific Surface Area: 6–15 m²/g
• Suitable for Specialized Applications such as:
• Rubber fillers
• Anti-static products

The Thermal Black process is ideal for producing carbon black with large particle size and low surface area, making it suitable for specific applications that require these properties.

Technical Properties and Quality Criteria of Carbon Black

The quality of carbon black is determined based on its physical characteristics and performance properties. Below are the key attributes and how they are measured:

Physical Properties

Functional Properties
• Abrasion Resistance:
Carbon black significantly enhances the abrasion resistance of materials like rubber, increasing product lifespan by 100–300% in rubber applications.
• Electrical Conductivity:
Carbon black can increase the electrical conductivity of materials (10⁻² to 10² S/cm) and is used in applications such as electronic components and conductive composites.
• UV Stability:
By absorbing UV radiation, carbon black prevents material degradation under sunlight and can extend product life up to 5 times.
• Coloring Power:
Carbon black offers high tinting strength (5–10 times stronger than mineral pigments) and is widely used as a black pigment in various industries.

Testing Methods and Quality Control

To ensure the quality and performance of black pigment, several tests are carried out:
• Particle Size and Distribution:
Measured using electron microscopes and laser diffraction equipment to ensure uniformity.
• Thermal Stability:
Samples are exposed to high temperatures, and any color change or property variation is evaluated.
• Adhesion and Flexibility:
Tested on various substrates to determine resistance to stretching and compatibility with coatings.
• Coverage and Dispersibility:
Assessed through colorability tests on different materials and UV resistance evaluations.
• Environmental Resistance:
Resistance to moisture, pollution, and corrosion is tested to verify durability.

Industrial Applications of Black Pigment

Black pigment is widely used across many industries. Below are some of its most important applications:
• Rubber and Tire Industry (70% of Global Use)
Enhances mechanical strength, abrasion resistance, and helps control thermal properties.
Typical Tire Formulation:
• 25–35% Carbon Black
• 50–60% Natural/Synthetic Rubber
• 10–15% Additives
• Plastics Industry (15% of Use)
• Polyolefins: Colored masterbatches
• PVC: Building products
• Engineering Polymers: Automotive components
• Paint and Coatings Industry (10% of Use)
Used in automotive paints, industrial coatings, and printing inks
• Emerging Applications
• Lithium-ion batteries
• Conductive composites
• Electronic inks

Commercial Grades of Carbon Black and International Standards

Carbon black is categorized into various types based on its properties and applications. One of the most widely used classification systems is the ASTM categorization.

Environmental and Safety Issues

The use of carbon black can involve environmental and safety issues that need to be taken into consideration.

Safety Considerations
• Skin contact: May cause irritation.
• Inhalation: Pulmonary hazards (maximum permissible exposure 3.5 mg/m³). Use of masks and proper ventilation systems is essential when working with carbon black.
• Storage: Should be kept in a dry, cool place away from oxidizing agents.

By following safety guidelines and using appropriate technologies, environmental and safety risks related to the production and use of carbon black can be minimized.

To select the most suitable type of carbon black, the following factors should be considered:
• Required particle size
• Desired specific surface area
• Degree of electrical conductivity
• Desired abrasion resistance
• Budget limitations

Considering the wide range of applications of this material, it is recommended to consult with industry specialists or reputable suppliers for the most accurate selection.

In general, when choosing industrial pigments, keep the following in mind:
• Choose based on your needs. Therefore, it is a prerequisite to know which pigment to use for which product to avoid waste.
• Sufficient quantity: As a habit, customers usually buy in large volumes to get reasonable prices. In any case, pigment waste is easy to occur during use.
• Supplier: Today, there are many common industrial pigments available on the market. To be able to purchase products that meet quality standards, it is essential to find reputable suppliers.