The liquid mixed metal stabilizers 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 stabilizer systems are based on Ba, Zn, Ca, Mg or K carboxylates. In general liquid mixed metals like Ba-Zn, Ca-Zn and Mg-Zn require the addition of co-stabilisers, antioxidants and organo-phosphites to provide optimum performance. The costabilizers are usually imparted to the liquid mixed metal stabilizer system. To adjust the viscosity different solvents are used including hydrocarbon solvents and plasticisers.
Liquid Ba-Zn stabilizers and liquid Ca-Zn stabilizers have successfully replaced cadmium-based stabilizers in any PVC semi-rigid and flexible applications. The stabilizers 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 stabilizer 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 stabilizers 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.