Permanent, Transparent, Non-Blooming and Non-Hygroscopic Antistatic Agents Based on Combined Neoalkoxy Organometallics

摘要

Minor amounts of thermally and hydrolytically stable combined dissimilar polarity type neoalkoxy titanates and/or zirconates can be added directly into the polymer during the thermoplastic or thermoset compounding phase at temperatures in excess of 200℃ to form bipolar layers that provide a transparent, non-blooming organometallic transfer circuit resulting in a volume as well as surface antistatic effect. The permanent antistatic effect depends upon a complete dispersion of the combined organometallics and thus works differently than conventional surface blooming hygroscopic antistats that rely on polymer incompatabilization and resultant surface blooming to attract ESD atmospheric moisture to the thermoplastic surface in environments having humidity greater than 25%. A transparent film results since the combined organometallics are of good color and solubilize into the polymer, and are not made of insoluble conductive particulate or cobalt-based metallocenes,. Specifically, it will be shown that when using a combined trineoalkoxy dodecylbenzene sulfonyl zirconate/trineoalkoxy aliphatic amino zirconate antistatic agent, transparent olefin films remain clear after long-term aging tests. Data will show that the resistivity will be lowered from 10~(13) to 10~(11) Ω/sq. for 30 mil compression molded slabs when 1% of the new and novel antistat is added to polypropylene in an intensive mixer (Banbury) operating in the range of 160 to 190℃ - and the mixer compounding conditions are changed (to increase specific energy input) from 30-second drop after flux occurs @ 50 rpm to 2-3 minutes drop after flux occurs at 100-125 rpm. Differences in ESD effects in HDPE using a 2-roll mill vs. a twin-screw extruder will be discussed. Effects will be shown in various other polymer disciplines such as LLDPE, PVC, PETG, Nylon and PES. For example, a clear thermoplastic polyurethane having a surface resistivity and a volume resistivity of 1.3 x 10~(16) Ω/sq. and 1.7 x 10~(15) Ω-cm respectively will exhibit ESD properties of 7.4 x 10~(12) Ω/sq. and 4.6 x 10~(11) Ω-cm when 2% by weight of PU of a 60% active combined trineoalkoxy zirconate on silica powder masterbatch is used.