Abstract: A composite body comprising a porous layer (1) made from oxide particles connected to one another and partially to a substrate, containing at least one oxide of the elements Al, Zr, Ti or Si, and comprising a further porous layer (2) at least on one side, having oxide particles connected to one another and partially to the layer (1) and containing at least one oxide of the elements Al, Zr, Ti or Si, wherein the oxide particles in the layer (1) have a greater average particle size (d50 is 0.5 to 4 ?m) than the oxide particles in the layer (2) (d50 is 0.015 to 0.15 ?m), characterised in that a polymer coating (PB) is provided on or above the layer (2), containing one or more polysiloxanes. A method for producing corresponding composite bodies and to the use thereof.

Abstract: The present invention provides a composite body having, on a porous substrate and in the interstices of the substrate that includes fibers, preferably of an electrically nonconductive material, a porous layer (1) composed of oxide particles bonded to one another and partly to the substrate that include at least one oxide selected from oxides of the elements Al, Zr, Ti and Si, preferably selected from Al2O3, ZrO2, TiO2 and SiO2, and having, at least on one side, a further porous layer (2) including oxide particles bonded to one another and partly to layer (1) that include at least one oxide selected from oxides of the elements Al, Zr, Ti and Si, preferably selected from Al2O3, ZrO2, TiO2 and SiO2, where the oxide particles present in layer (1) have a greater median particle size than the oxide particles present in layer (2), which is characterized in that the median particle size (d50) of the oxide particles in layer (1) is from 0.

Abstract: The present invention provides a composite body having, on a porous substrate and in the interstices of the substrate that includes fibers, preferably of an electrically nonconductive material, a porous layer (1) composed of oxide particles bonded to one another and partly to the substrate that include at least one oxide selected from oxides of the elements Al, Zr, Ti and Si, preferably selected from Al2O3, ZrO2, TiO2 and SiO2, and having, at least on one side, a further porous layer (2) including oxide particles bonded to one another and partly to layer (1) that include at least one oxide selected from oxides of the elements Al, Zr, Ti and Si, preferably selected from Al2O3, ZrO2, TiO2 and SiO2, where the oxide particles present in layer (1) have a greater median particle size than the oxide particles present in layer (2), which is characterized in that the median particle size (d50) of the oxide particles in layer (1) is from 0.