摘要 |
<p>Modified mineral fillers derived from either a coarse particle kaolin clay or a coarse particle ATH, having excellent utility in thermoset polymers as low paste viscosity fillers are disclosed. The method of treatment involves the use of specific weight ratio combinations of a silane and a long chain aliphatic alcohol. The treatment of clay can also involve the auxiliary use of a surfactant in small amounts, which is utilized to emulsify the silane and aliphatic alcohol treatment components in water either individually or as a co-emulsion blend prior to their addition to the clay. The surfactant, which is preferably a nonionic surfactant having a HLB value of 12 - 18, aides in uniformly treating all the clay particle surfaces with the silane/alcohol treatment combination. Coarse particle clays having general utility in the invention are those having an average Stokes equivalent particle diameter of at least 3.0 microns, while the coarse particle ATH fillers having general utility in the invention are those having a BET surface area value less than 5.0 m2/g. Clays or ATH so treated with the inventive silane/alcohol treatment provide unique viscosity reduction benefits in thermoset polymers unattainable by using either treatment additive alone in any amount. This low viscosity characteristic allows the treated mineral products to be used at high loadings in various thermoset compounds, as fillers or extenders, which is advantageous in terms of reducing cost and/or gaining certain performance properties, such as physical reinforcement, composite surface smoothness or flame retardancy.</p> |