Renewable Resource-Based Raw Materials for Aliphatic, High UV-Resistant PU Coating Systems

Bio-based coatings are becoming more widely used globally. A discussion with Younes Khermane from Alberdingk Boley on bio-based coatings demonstrates growing demand for renewable resource-based and UV-resistant polyols. Alberdingk Boley continues to expand its product range with renewable resource-based products. The company has 193 years of experience in vegetable oil processing and guarantees the production of sustainable oleochemicals with superior properties under its 100% PU polyol product range. Demands in the floor coating market are becoming more complex with new requirements rather than simple protection. These new requirements can be listed as aesthetic appearance, high durability, light fastness and fire resistance. Alberdingk Boley has developed UV-resistant, castor oil-based Albodur® 1055 to meet market needs.

Why Is Castor Oil a Perfect Source for Polyols?

Castor oil is the only natural oil with monofunctional OH groups that can be used in polyurethane systems. Oil properties provide polyurethane systems with natural hydrophobicity, insulating properties and fire resistance. Unlike other oils, castor oil viscosity is temperature-dependent and the lowest viscosity is achieved at 40°C. Castor oil's ease of use, low energy consumption in pumping and ability to provide high pigment loading make it ideal to process between 30°C and 40°C. Alberdingk Boley sells various castor oil derivatives and castor oil-based polyols.

Floor Coatings: Changing Requirements Over Time

In the past, floor coatings were used particularly in industrial areas due to their high chemical, physical and mechanical resistance. Today, their use in floor coatings in residential areas is increasing for decorative and special purposes. Examples include areas where food contact is important, hospitals where hygiene is important, and schools where easy cleaning is important. Demand is also increasing for areas such as passenger ship decks where weather resistance, strength, UV protection and optical properties are particularly important. Castor oil-based polyols have long been established materials as UV and impact-resistant alternatives to epoxy systems in polymer floor coatings. They can be used as primer and self-leveling topcoat and are particularly used with 100% polyol-based primers on wet concrete or oily concrete substrates.

Floor Coating Structure

Floor systems always have a multi-layer structure. The primer layer isolates dust in the concrete and facilitates adhesion of the layers to be applied. Then a leveling or equalizing layer/mortar is applied that fills voids and has a 1 mm film thickness. Next, the most important layer, called self-leveling coating, is applied. This coating provides physical and chemical resistance and of course color and optical appearance. Particularly in areas with high pedestrian or machine traffic, a solvent or water-based topcoat is required and these surfaces can be polished.

Aesthetic, UV-Resistant Formula Is Easy: Albodur® 1055

The polyol offers a hydrophobic property and an extremely pale appearance as a clear resin. Furthermore, the product provides the same properties when combined with low viscosity isocyanate. The polymer structure of Albodur® 1055 is suitable for reducing the amount of isocyanate used in the total system without weakening fundamental qualities such as good processability, versatility and compatibility with mechanical properties. Albodur® 1055 is a VOC-free polyol and provides excellent UV stability beyond current values of decorative 2K PU coating systems. The light stability of a PU system made using Albodur® 1055 cross-linked with aliphatic isocyanate is over 1000 hours according to QUV A testing. Additionally, it provides absolutely crystal-clear transparency for decorative coatings. In summary, compared to alternative technologies, this polyol offers unique performance in the formulation of light-resistant VOC-free 2K PU coatings. Albodur® 1055 is a pharmaceutical castor oil-based, UV-resistant polyol produced at the company's Krefeld production facility in Germany. The product consists of 65% renewable raw materials by content. This environmentally friendly innovative system is comparable to pure synthetic systems made from petroleum derivatives.

How Does Albodur® 1055 React with Isocyanate?

Thanks to aliphatic technology, the effect of isocyanate and catalyst is as strong as the effect of polyol. The best catalyst effect is observed in DOTL types and especially in dioctyl carboxylate. Mixing times and methods are very important for aliphatic polyols and isocyanate, because the polyol/isocyanate reaction is much slower compared to the isocyanate/water reaction. As a result, higher isocyanate usage can increase the tendency to react with moisture. General application areas for Albodur® 1055 are floor coverings (MDI-based), coatings (HDI-based), elastomers/sealants, corrosion protection and one and two-component adhesives. Sources [1] Alberdingk Boley Technology Information – Albodur® Castor oil based polyols [2] Alberdingk Boley Product Information – Albodur® 1055 [3] PU Magazine – VOL. 16, NO. 5 – October/November 2019  

Younes Khermane Chemist Technical Marketing, Dispersions Alberdingk Boley GmbH

 

Beyhan Dayıbaş Senior Chemical Engineer Technical Sales Specialist Ravago Chemicals Turkey Chemical Raw Materials Sales and Marketing Inc.