A Brand-New Solution for Hot Melts

A New Solution for Hot Melts Naphthenic mineral oils enhance component compatibility, providing hot melt adhesive manufacturers with new and more flexible formulations. Hot melt adhesive manufacturers can achieve significant cost advantages by using metallocene-based polyolefins and resins derived from natural sources. Resins from natural sources represent a more cost-effective tackifier option compared to alternative hydrocarbon resins. One reason for this is that such resins are produced using renewable raw materials. Manufacturers typically encounter problems when incorporating these generally incompatible components into hot melt formulations. The metallocene catalyst is considered revolutionary for the polymer industry, however natural resins are not compatible with metallocene polyolefins (mPOs), which are much easier to produce than conventional polymers. At this point Nynas oils offer a solution. Naphthenic mineral oils enable greater flexibility in hot melt formulations and reduce the risk of encountering supply issues in raw materials, allowing for compatible blends and showing considerable promise in this respect. Research conducted by Nynas demonstrates that a high-polarity oil exhibits superior performance. Natural-based resins are polar materials and in hot melts the resin typically dissolves in the oil. However, in final formulations containing polymers, peel performance tests of hot melt formulations show that oil polarity is not the only determining factor for compatibility between natural resins and mPOs.

Investigation of Mineral Oil, Natural Resin and mPO Hot Melt Formulations

Rheology and cloud point studies demonstrate oil/resin and resin/polymer compatibility for various tackifiers and oils with different properties. The rheological data in Figure 1 show how the oil can typically make incompatible blends compatible. Figure 2 shows that while hydrocarbon resin formulations generally increase peel strength, the results are comparable. Some alternative resin formulations show better peel strength on glass and polyethylene surfaces. Anna Eriksson Technical Manager Nynas