Raw Materials Based on Renewable Resources for Aliphatic PU Coating with High UV Resistance

Biobased coatings usage is becoming more common worldwide. Discussion about biobased coatings with Mr. Younes Khermane from Alberdingk Boley shows that there is an increasing demand for UV-Stable polyols based on renewable resources. Alberdingk Boley is expanding its product range based on renewable resources. The company has 193 years' experience of processing vegetable oils and commits to produce sustainable oleochemicals with superior properties under 100% PU polyols product range. The floor coating market's demands are becoming more complex than pure protection. The new requirements can be categorized as aesthetic appearance, high durability and light fastness, and fire-resistance. Alberdingk Boley has developed Albodur® 1055, which is UV-stable and based on castor oil, to meet the market requirements.

Why is Castor Oil the Perfect Base for Polyols?

Castor oils are the only OH-functional natural oils that can be used in polyurethane systems. The oil characteristics offer natural hydrophobicity to polyurethane systems and support isolation properties as well as fire resistance. Unlike other oils, the viscosity of castor oil is strongly dependent on temperature. The lowest viscosity can be achieved at 40°C. Castor oil is ideally delivered between 30°C and 40°C to provide easy handling, low energy consumption for pumping, high pigment loading, etc. Alberdingk Boley offers various kinds of castor oil derivatives and polyols based on castor oil.

Floor Coatings: Changing Requirements Over Time

In the past, floor coatings have mainly been used in industrial areas due to their high chemical, physical and mechanical resistance. Nowadays, the use of floor coatings in residential areas is increasing for decorative and specific purposes, such as hygiene requirements in hospitals, easy-to-clean properties for schools, and in areas where food contact is important. Especially, PU floor coating demand is increasing in areas where weather resistance, durability, UV protection and excellent optical properties are required, such as sun decks of cruise ships. Castor oil-based polyols have long been approved in polymer floorings as a UV-stable and impact-resistant alternative to epoxy systems. They can be used as primers and self-leveling topcoats. 100% polyol-based primers are used particularly on damp concrete or oily concretes. Floor Coating Structure Floor systems always have a multi-layer build-up. The primer layer seals dust on the concrete and provides adhesion to the following layers. It is followed by a balancing or leveling layer/mortar which fills up pores and has 1 mm film thickness. Then, the most important layer, which is called self-leveling coating, is applied. Areas with high foot or machine traffic will also need a topcoat which is mainly solvent or water-based and can be reworked with a polish.

Aesthetic, UV Stable, Easy to Formulate: Albodur® 1055

The polyol offers a hydrophobic property and an extremely pale appearance as neat resin. Besides, when the product is combined with low viscosity isocyanate, it provides the same properties. The polymer structure of Albodur® 1055 allows reduction of isocyanate requirement in the total system without losing basic features such as good workability, broad versatility and compatibility profile, as well as mechanical properties. Albodur® 1055 is a VOC-free polyol and provides excellent UV-stability beyond the current limits of decorative 2K PU coating systems. PU system light stability can be obtained for more than 1,000 hours in QUV-A exposure testing with an aliphatic isocyanate crosslinked Albodur® 1055. Besides, it provides absolutely crystal-clear appearance for decorative coatings. In summary, compared to alternative technologies, this polyol offers a unique performance profile in the formulation of light-stable, VOC-free 2K PU coatings. Albodur® 1055 is a UV-stable polyol based on pharmaceutical castor oil that is manufactured at the production site in Krefeld, Germany. It has a guaranteed 65% content of renewable raw material. This environmentally friendly innovation is comparable to pure synthetic systems made from petroleum derivatives.

How Does Albodur® 1055 React with Isocyanate?

Due to the aliphatic technology, the impact of the isocyanate and the catalyst is as strong as the impact of the polyol. The best catalyzing effect was observed with DOTL types, especially dioctyltincarboxylate. Blending time and methods are very important for aliphatic polyols and isocyanate because the polyol/isocyanate reaction is very slow compared to the isocyanate/water reaction. Consequently, increased isocyanate usage can boost the tendency of reaction with moisture. General applications are floorings (MDI-based), coatings (HDI-based), elastomers/sealants, corrosion protection, and one- and two-pack adhesives. References [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 MSc Chemical Engineer Technical Sales Specialist Ravago Chemicals Turkey Kimyasal Hammaddeler Satış ve Pazarlama A.Ş.