[Vision Watch] Carbon Black Pigment Alternative with Outstanding LiDAR Signal Response—Spectrasense™ Black L 0082 Delivers Neutral Gray and Dark Colors with Outstanding Solar[...]

Why Do Objects Coated in Conventional Carbon Black Pigments Impede LiDAR Sensors

LiDAR sensors face a significant challenge when it comes to detecting objects, including other vehicles, that are coated with colors containing conventional carbon black (P.Bk.7) pigments. These pigments, which are widely used in most colors, particularly neutral grays or dark low-chroma colors, have high NIR absorption, leading to a decrease in LiDAR detectability. Spectrasense™ Black L 0082 is here to change that.

The replacement of carbon black with the NIR-transparent Spectrasense™ Black L 0082 allows for the formulation of automotive coating systems with enhanced NIR signal reflection and improved LiDAR detectability. It offers superior coloristic performance and enables the formulation of neutral grey and rich dark shades near masstone.

How Does Spectrasense™ Black L 0082 Eliminate Trade-Offs Posed by Carbon Black Pigments

Previously, automakers and consumers faced a trade-off between luxurious color design and superior LiDAR signal response. The 'go-to' standard black pigment, carbon black, supports the formulation of dark shades in automotive coatings, from deep blacks to reds, blues, and greens, as well as neutral colors, such as metallic grays; carbon black also enhances secondary properties such as coating opacity-playing a vital role in automotive body color design-a key factor in the discerning consumer's decision to purchase a new vehicle.

With the introduction of Spectrasense™ Black L 0082, this trade-off is no longer necessary, as it offers both superior color design and LiDAR signal response.

By replacing carbon black with the functional Spectrasense™ Black L 0082, coating manufacturers can deliver automotive coatings with the broadest gamut of colors, including neutral gray and rich dark tones, while providing near-infrared (NIR) reflectivity and detectability. This enables improved autonomous vehicle driving performance without compromising the visual design.

What Is Near-Infrared Light

Infrared radiation (IR)-also called infrared light-is the electromagnetic radiation range (EMR) occupying the spectrum between microwaves and visible light.

The infrared spectrum can be further divided into near-, mid-, and far-infrared light. Near-infrared light (NIR) is the section of electromagnetic radiation (EMR) wavelengths nearest to, but just beyond, what human beings can see.

What is LiDAR

Light Detection And Ranging (LiDAR) systems are three-dimensional detection systems for the entire physical environment surrounding a LiDAR sensor array. LiDAR works like the more familiar RAdio Detection And Ranging (RADAR) systems.

Where RADAR systems use longer wavelength radio waves to determine the distance and velocity of targets, LiDAR systems use shorter wavelength light emitted from NIR lasers for improved spatial accuracy.

It is important to note that LiDAR systems use lasers at wavelengths that are safe for human beings and animals to interpret the immediate surroundings. They render all detected objects visible in three dimensions for highly accurate 3D representations of the surveyed environment.

Multiple LiDAR sensors work by sending pulsed NIR light waves into the surrounding environment. Each NIR light pulse bounces off objects located within range of each sensor, and each sensor automatically measures the time it takes for each return pulse to reach it, facilitating the calculation of the distances to objects.

By repeating this relatively simple process millions of times per second, LiDAR sensors create precise, real-time 3D maps of surrounding environments-also called point clouds. In autonomous vehicles, onboard computers use LiDAR point clouds to identify where objects are located and thereby navigate a safe path around them.

How Do LiDAR Sensors Work on Autonomous Vehicles

Global automakers are now developing the necessary next-generation mobility technologies to further facilitate autonomous vehicle driving. Light detection and ranging (LiDAR) sensors can identify the shape, distance, and velocity of surrounding objects by irradiating them with NIR lasers and measuring the reflected light received from them.

This highly accurate spatial information is necessary for the autonomous vehicle to navigate accurately and for vital collision avoidance. However, LiDAR sensor cognitive impairment remains a significant factor in autonomous automobile accidents, and color pigmentation can be a significant contributor.

What Are the Drawbacks of Carbon Black Pigment-Based Automotive Coatings

Automotive manufacturers increasingly recognize the value of NIR reflective coatings for all color offerings to facilitate LiDAR NIR light detection. Carbon black pigments used in automotive coating systems and plastic components contain fine carbon particles that absorb radiation at wavelengths across the whole visible and NIR electromagnetic spectrum.

The absorbance of NIR wavelengths is not only problematic for LiDAR-based driving systems but also results in heat absorption. Increased solar radiation absorption raises the temperature of vehicle structures, which, apart from time-to-comfort-related issues, can affect the performance of onboard electronics.

It is important to note that exposing automotive electronic components to high temperatures often increases thermal stress, degrading their performance and reliability over time.

Through the development of NIR functional black pigments, the DIC Group pigments business unit developed NIR management components for conventional multi-layer coating systems. Using an NIR transparent-colored topcoat layer combined with an NIR reflective primer/substrate, an automotive coating can be formulated with strongly enhanced NIR reflection and detection.

How Do New Automotive Paint Color Formulations Support Superior LiDAR Detection

With the development of the Spectrasense™ brand, it is possible to formulate clean, deep, and dark colors without using carbon black pigments.

Traditionally used carbon black pigments in the primer and basecoat layers can be replaced with NIR-transparent or NIR-reflective functional black pigments, delivering high-performance color properties as well as the desired NIR reflectivity for LiDAR detection and low heat absorbance.

Automotive coating manufacturers can also use a similar pigmentation approach if the paint system in question omits conventional primers and instead uses a system comprising two modified base coat layers to fulfill the combined roles of the primer and base coat.

As NIR-transparent/NIR-reflective coatings employing functional black pigments may also be applied to a wide range of industrial products that employ LiDAR sensors or require heat management capability, the sky is the limit on potential applications and use case scenarios.

Revolutionary Perylene Black Pigment with High Jetness and Neutral Coloristics for Ease of Color Formulation

Global Innovation Manager-HP Organic Pigments, Color Materials, Sun Chemical, Switzerland, Dr. Paul Brown notes, "We successfully developed pigments for reducing NIR wavelength absorption for improved heat-shielding in building materials and improved this pigment technology for automotive coatings."

Global automakers and automotive coating and plastics suppliers have long-needed pigments with NIR management capabilities, initially for heat management and later for LiDAR detection applications. The latest perylene black developments have achieved NIR management for heat management and LiDAR detection applications, along with improved coloristic performance for the near-masstone dark shades and color neutrality in metallic greys.

"We needed to develop a new functional black pigment to replace carbon black that was readily usable in color formulations and also easy to incorporate into coating systems for better LiDAR reflection and heat management."

Optimal NIR Performance in All Color Compositions

By using this new neutral-colored black pigment in combination with other NIR reflective or non-absorbing pigments, DIC has created formulation capabilities for the primer and basecoat layers that deliver excellent LiDAR reflectivity in a wide range of desirable colors.

Initially introduced in April 2021, the improved NIR-transparent Spectrasense™ Black L 0082 has already drawn praise from global automotive coating manufacturers and automakers alike for its potential to eliminate the automotive industry's dependence on conventional carbon black pigments and facilitate NIR functional coating performance.

As the new Spectrasense™ Black L 0082 produces both neutral tones and higher jetness than previously achievable for a NIR functional black pigment, global automotive coating manufacturers can now produce neutral grays and blacks in a similar way to carbon black pigments without having to compensate for the unwanted color shift of the previously available pigments.