Layer material for corrosion protection and solar receiver having such a layer material

Abstract

A layer material for corrosion protection and to a solar receiver having such a layer material is provided. The layer material comprises a binding agent consisting of a resin containing at least one of the following substances: oligo- or polysiloxane, silicone resin, silicone, silicate, polyphosphate, and which is dissolved in a solvent, a pigment consisting of zinc microparticles having an average diameter of at least 1 um, wherein a further pigment consisting of titanium oxide or silicon oxide nanoparticles having an average diameter of no more than 100 nm is present in the layer material. The layer advantageously has a self-healing effect in addition to the corrosion protection effect thereof owing to the use of zinc particles.

1 . A layer material for corrosion protection, comprising:
 a binder having a resin containing at least one of the following substances: oligosiloxane or polysiloxane, silicone resin, silicone, silicate, polyphosphate, and which is dissolved in a solvent; and   a pigment including microparticles of zinc having a mean diameter of at least 1 μm;   
       wherein a first further pigment including nanoparticles of titanium oxide or silicon oxide having a mean diameter of at most 100 nm is present in the layer material. 
     
     
         2 . The layer material as claimed in  claim 1 , wherein the microparticles of zinc have a mean diameter of at most 100 μm. 
     
     
         3 . The layer material as claimed in  claim 1 , wherein the nanoparticles of titanium oxide or silicon oxide have a mean diameter of at least 10 nm. 
     
     
         4 . The layer material as claimed in  claim 1 , wherein the layer material contains a second further pigment including aluminum oxide, zirconium oxide or silicon oxide, with a mean diameter of the particles of at least 1 μm, as filler. 
     
     
         5 . A solar receiver for a solar power plant, comprising:
 an absorber tube made of a metal; and   an envelope tube made of glass, which surrounds the absorber tube to form an interstice,   
       wherein the interstice is hermetically sealed, 
       wherein an externally accessible part of the solar receiver outside the envelope tube is equipped at least partially with a layer made of a cured layer material. 
     
     
         6 . The solar receiver as claimed in  claim 5 , wherein the hermetic seal of the interstice is ensured by a weld seam, wherein the weld seam is equipped on the externally accessible part thereof with the layer made of the cured layer material. 
     
     
         7 . The solar receiver as claimed in  claim 5 , wherein the cured layer material on the envelope tube comprises:
 a binder of a resin containing at least one of the following substances:   oligosiloxane or polysiloxane, silicone resin, silicone, silicate, polyphosphate, and which is dissolved in a solvent; and   a first pigment including microparticles of zinc having a mean diameter of at least 1 μm, wherein a second pigment including nanoparticles of titanium oxide or silicon oxide having a mean diameter of at most 100 nm is present in the cured layer material.   
     
     
         8 . The solar receiver as claimed in  claim 7 , wherein the microparticles of zinc have a mean diameter of at most 100 μm. 
     
     
         9 . The solar receiver as claimed in  claim 7 , wherein the nanoparticles of titanium oxide or silicon oxide have a mean diameter of at least 10 nm. 
     
     
         10 . The solar receiver as claimed in  claim 7 , wherein the cured layer material contains a third pigment including aluminum oxide, zirconium oxide or silicon oxide, with a mean diameter of the particles of at least 1 μm, as filler. 
     
     
         11 . The solar receiver as claimed in  claim 6 , wherein the cured layer material on the weld seam comprises:
 a binder of a resin containing at least one of the following substances: oligosiloxane or polysiloxane, silicone resin, silicone, silicate, polyphosphate, and which is dissolved in a solvent; and   a pigment including microparticles of zinc having a mean diameter of at least 1 μm, wherein a first further pigment including nanoparticles of titanium oxide or silicon oxide having a mean diameter of at most 100 nm is present in the cured layer material.   
     
     
         12 . The solar receiver as claimed in  claim 11 , wherein the microparticles of zinc have a mean diameter of at most 100 μm. 
     
     
         13 . The solar receiver as claimed in  claim 11 , wherein the nanoparticles of titanium oxide or silicon oxide have a mean diameter of at least 10 nm. 
     
     
         14 . The solar receiver as claimed in  claim 11 , wherein the cured layer material contains a second further pigment including aluminum oxide, zirconium oxide or silicon oxide, with a mean diameter of these particles of at least 1 μm, as filler.