Smart Coatings – Smart, Functional, Responsive

Microencapsulation Enables New Product Benefits

Paints and varnishes are applied onto a broad variety of surfaces to provide a protection against damages, corrosion or premature aging. One approach to create new property profiles for coatings is to use the microencapsulation technology.

Your Know-How is at the Core – Our Expertise is in the Capsule Wall
Today, smart functions call for active substances that are rendered more stable by encapsulation and, due to their small size, can be incorporated inconspicuously into paints and varnishes. Koehler Innovative Solutions develops stable microcapsules for your particular application with the appropriate wall material and release profile. Our experience in development and production ensures a rapid market launch. Take advantage of our expertise for your innovative ideas.

Pigments – More than just Decorative
For a long time, pigments were used in paints and varnishes exclusively for their decorative properties. Today, encapsulated and coated pigments offer far more functionality: e. g., the luminescence of certain pigments is used to make documents counterfeit resistant. In order to provide this functionality, the pigments are protected by a transparent encapsulation shell.

Catalysts – Reaction at the Breakage of a Capsule
In complex chemical mixtures, a free-standing catalyst can trigger undesirable reactions and interfere with the functions and properties of a coating. An excellent solution to provide the active component with a specific activity only for the desired reaction is its encapsulation in microcapsules. At a given point of time, the capsule wall will be destroyed mechanically; e. g. by ultrasound or temperature, and the encapsulated catalyst will be released.

Self-healing Polymers – Quicker than Corrosion
The first sign of damages to a protective varnish layer are microcracks, which expand rapidly if untreated, and accelerate the corrosion of the substrate due to penetration of water or oxygen. Microcapsules containing liquid, non-cured polymers in their core are incorporated into the varnish layer and thus provide a reservoir of crosslinkable active substance. Premature curing is prevented by the protective capsule wall until the capsule is destroyed by a damage to the varnish. The contents of the capsules are released and dispersed within the resulting crack by means of capillary forces. A catalyst, which is also included in said layer, starts to cross-link the polymer and the open spots are resealed.

Corrosion Indicators – Early Indication to Prevent Worse
Corrosion is not always directly visible for the eye. However, if it is ignored, a severe damage may result that, in turn, may lead to a severe safety hazard. Corrosion indicators in the lower varnish layer indicate a damage at an early stage. The concurrent incorporation of suitable inhibitors may directly suppress further oxidation. However, such substances often are not compatible with the other constituents of protective varnishes. A dosed release of these substances from microcapsules prevents undesired side reactions with other varnish components and ensures the functionality of the individual components.

Biocide – But Please with a Long-term Release
The environment in damp and wet areas promotes microbial growth. Biocides incorporated in silicone joint sealers are washed out, e. g., by showering with warm and surfactant-rich water, and the anti-microbial effect is lost after only a short time. By encapsulating the biocide, the active substance diffuses in a dosed and continuous way through the capsule wall into the sealant. This reduces the amount of active ingredient required while maintaining an effective killing of the microbes.

Lubricants – Lubrication on Demand
Lubricating agents reduce friction between two surfaces by means of a lipid film. Today, the use of lubricating grease is replaced by antifriction coatings, especially in the automotive sector. The efficiency of an antifriction coating is significantly improved with microencapsulated lubricants since the lubrication occurs when required. If the friction increases with an increasingly thinner lubricant layer, the capsules are destroyed and tearing of the lubricating film is prevented.

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