Industrial paints play an essential role in the protection and finishing of numerous materials. They are used in various sectors, such as the automotive, aeronautics, construction, or even metallurgy industries. Their composition and properties must meet precise requirements in terms of resistance, durability, and quality.

Chemical analysis allows for the characterization of these paints, the identification of their components, and the verification of certain of their properties. It thus contributes to quality control, the optimization of formulations, and compliance with regulatory requirements.

What is the composition of an industrial paint?

Manufacturers compose their paints by combining several elements in proportions adapted to the application and the desired performance:

• Pigments provide color and opacity. They can also contribute to certain properties, such as protection against corrosion,
• Binders ensure the cohesion of the coating and its adhesion to the substrate. They contribute in particular to its mechanical and chemical resistance,
• Solvents and dispersion media facilitate the application of paint by adjusting its viscosity. They may evaporate during drying or film formation,
• Additives are incorporated in small quantities to modify or improve certain properties: drying, UV resistance, stability, or ease of application.

What are the main categories of industrial paints?

Industrial paints are distinguished in particular by their formulation and their method of application:

• Solvent-based paints use organic solvents to disperse the components. They can offer good application and resistance properties, but their formulation can lead to emissions of volatile organic compounds (VOCs),
• The water-based ones use water as the main dispersion medium. They generally allow for a reduction in the use of organic solvents,
• Powder coatings are applied as a powder, then heated to form a continuous coating. They are notably used for their durability and method of application,
• Finally, those that are biobased incorporate raw materials derived from biomass, as a total or partial replacement for components of fossil origin.

Paints biobased : an evolution of industrial formulations

These paints incorporate bio-based materials, which can be used in the composition of binders, solvents, or additives. The use of these materials addresses several challenges for manufacturers: diversifying the resources used, integrating renewable raw materials, and evolving formulations. However, their use must remain compatible with the quality and performance requirements specific to each application.

The characterization of the biobased fraction can notably involve carbon-14 analysis, which allows for the distinction between biogenic carbon and fossil carbon.

Why perform a chemical analysis of industrial paints?

Chemical analysis makes it possible to better understand the composition of a paint and to verify some of its characteristics. It meets several industrial needs:

• Quality control: verifying the composition of products and their compliance with defined specifications,
• Comply with regulatory requirements: document the presence or content of certain components according to the required analyses,
• Optimize formulations: better understand the raw materials used and support research and development work.

The choice of analyses depends on the composition of the paint, the question asked, and the information sought.

What techniques are used to analyze paintings?

Several analytical methods can be used to characterize industrial paints. They provide complementary information about their composition.

• Carbon-14 analysis makes it possible to determine the proportion of carbon of biogenic origin relative to fossil carbon. It is notably used to characterize the biobased fraction of certain materials and formulations. The NF EN 16640 and ASTM D6866 standards govern methods for determining biobased carbon,
• Infrared (IR) spectroscopy allows for the identification of certain chemical groups and the characterization of the families of compounds present in a sample,
• Gas chromatography (GC) allows for the separation and analysis of certain volatile or semi-volatile compounds,
• Mass spectrometry allows for the characterization of compounds based on their mass-to-charge ratio and can be combined with other analytical techniques,
• X-ray fluorescence (XRF) makes it possible in particular to determine the presence and content of certain chemical elements, especially in pigments and mineral fillers.

Manufacturers choose to use these techniques alone or to combine them depending on the objectives of their study.

What is the role of a laboratory in the analysis of paintings?

A specialized laboratory supports manufacturers in characterizing their products and raw materials. The analyses make it possible to obtain data on the composition of paints, to control certain characteristics, and to support research and development initiatives.

They can also help to document the carbon content biobased of a formulation. The result of an analysis therefore provides an element of characterization, but does not in itself constitute a certification or the attribution of a label.