A silicone rubber insulator shed material, and a silicone rubber insulator and a preparation method therefor and an application thereof. The components of the silicone rubber insulator shed material comprise silicone rubber, iron oxide, nano-montmorillonite, fumed silica, aluminum hydroxide, a silane coupling agent, a vulcanizing agent, and hydroxy silicone oil, wherein the iron oxide and the nano-montmorillonite can slow down the thermal oxidation decomposition of the silicone rubber, thus improving the hydrophobicity, hydrophobic mobility and hydrophobic recovery of the silicone rubber composite insulator, thereby solving the technical problem in the prior art that the aging decomposition resistance of silicone rubber needs to be improved.

Embodiments in accordance with the present invention encompass compositions containing a blend of polymers formed from a variety of polycycloolefinic monomers at least one of which monomer contains an olefinic functionality and another monomer contains an anhydride functionality, melamine, montmorillonite and optionally other fillers such as silica, a crosslinker, a free radical initiator, a tackifier and one or more suitable additives. The compositions of this invention can be formed into a variety of three-dimensional insulating articles upon exposure to suitable high temperature, such as for example films. The objects formed from the compositions of this invention exhibit hitherto unattainable low dielectric constant and low-loss properties, fire retardancy and very high thermal properties. The compositions of this invention are useful in various applications, including as insulating materials in millimeter wave radar antennas, among others. The films formed from the compositions of this invention exhibit a UL-94 rating of at least V-1, dielectric constant (Dk) less than 2.8 and dielectric dissipation factor (Df) of less than 0.002.

Interference pigments based on SiO.sub.2 flakes coated with crystallites of alpha-Fe.sub.2O.sub.3. Also, a process for the preparation of interference pigments that comprise SiO.sub.2 flakes coated with a crystallite of alpha-Fe.sub.2O.sub.3, by a wet-chemical process in a fluidised bed, by a CVD process, by a PVD process, or by any combination of said processes. Also, the use of interference pigments based on SiO.sub.2 flakes coated with crystallites of alpha-Fe.sub.2O.sub.3, in particular in paints, coatings, industrial and automobile paints, ceramic materials, plastics and cosmetic formulations.