Siloxane Masterbatch MB50-007

Ultra-high molecular weight siloxane polymer dispersed in acrylontrile butadiene styrene.

DOW CORNING MB50-007 Masterbatch is a pelletized formulation containing 50% of an ultra-high molecular weight (UHMW) siloxane polymer dispersed in acrylonitrile butadiene styrene. It is designed to be used as an additive in polypropylene compatible systems to impart benefits such as processing improvements and modification of surface characteristics.

Liquid siloxane plastic additives have been used for several years to improve the lubricity and flow of thermoplastics. They are effective in this role although some difficulties have been experienced in the incorporation of liquids into thermoplastic melts without the use of specialized equipment. It has also been difficult to produce masterbatches with greater than 20% liquid siloxane because of processing difficulty and bleed problems.

The DOW CORNING® MB Series Masterbatches address these problems by supplying a high concentration of an ultra-high molecular weight (UHMW) siloxane as a dispersion in a dry pellet form in a variety of thermoplastics.

BENEFITS
When DOW CORNING MB50-007 Masterbatch is added to ABS or similar thermoplastics, at a level of 0.2% w/w to 2.0% w/w, improved processing and flow of the resin is expected, leading to better mold filling and mold release, less extruder torque, faster throughput and less warpage of the molded part. At higher addition levels, 2% w/w to 10% w/w DOW CORNING MB50-007 Masterbatch, improved surface properties are expected, including lubricity, slip, lower coefficient of friction as well as mar and abrasion resistance.

The DOW CORNING MB50 Masterbatch series of solid additives are expected to give improved benefits compared to conventional lower molecular weight siloxane additives, e.g. less screw slippage, improvement in release, a lower coefficient of friction and a broader range of performance capability.

HOW TO USE
The DOW CORNING MB50 Masterbatch series should be used in the same way as the thermoplastic on which they are based. Sufficient of DOW CORNING MB50-007 Masterbatch should be blended with virgin polymer pellets to give the desired silicone level in the final product. DOW CORNING MB50 Masterbatch pellets can be added during compounding in a single screw extruder or added at the feed hopper during injection molding or extrusion.