The liquid mixed metal stabilisers are used in several PVC flexible applications like: calendered films; extruded profiles; injection moulded, soles, footwear; extruded hoses and plastisols (flooring, wall covering, artificial leather, coated fabrics, toys).
Liquid mixed metal stabiliser systems are based on Ba, Zn, Ca, Mg or K carboxylates. In general liquid mixed metals like BaZn, CaZn and MgZn require the addition of co-stabilisers, antioxidants and organo-phosphites to provide optimum performance. The costabilisers are usually imparted to the liquid mixed metal stabiliser system. To adjust the viscosity different solvents are used including hydrocarbon solvents and plasticisers.
BaZn stabilisers have successfully replaced Cadmium-based stabilisers in many PVC semi-rigid and flexible applications.
The stabilisers are formulated to meet specific requirements such as good initial colour, long-term stability, good transparency, good printability, weatherability, ageing resistance, good compatibility with all types of PVC, with fillers, and pigments. A good stabiliser achieves the best possible compromise of all the necessary requirements, including cost.
In recent years, different technologies have been introduced to the industry to improve VOC (volatile organic compounds) emissions in flexibles articles, particularly in relation to the building and construction industry. Low emission and low odour are the key characteristics required by the industry and reductions in VOCs can be achieved using Ca/Zn solids, phenol-free liquids and pastes. The available stabilisers are suitable for all kind of PVC applications: transparent, filled, pigmented, technical and food contact. In case of pastes, the liquid carried is generally ESBO or plasticisers.