| 摘要 |
Reflector for technical lighting purposes, having a reflecting surface of aluminum and a protective, transparent, pore-free barrier layer of aluminum oxide produced by anodizing having a dielectric constant epsilon of 6 to 10.5 at 20 DEG C., where the barrier layer is of thickness d that either satisfies the condition a) for constructive interference: dxn=kx gamma /2+/-20 nm or b) for achieving a color-toned reflector surface: [kx gamma /2+20 nm]<dxn<[(k+1)x gamma /2-20 nm] or c) for using as starting material to produce reflectors with low index/high index multi-layer coatings that increase reflectivity. dxn=lx gamma /4+/-20 nm where n is the refractive index of the barrier layer, lambda is the average wave length of the light striking the surface of the reflector, k is a natural number and l is a natural number that is uneven. The thickness of the barrier layer lies between 60 and 490 nm and does not vary by more than +/-5% over the whole of the aluminum surface. The aluminum surface is anodically oxidized in an electrolyte that does not redissolve the aluminum oxide layer. The electrolyte may be a solution of organic or inorganic acids such as sulphuric or phosphoric acids at low concentrations, boric acid, adipic acid, citric acid or tartaric acid or mixtures thereof, and preferably has a pH of 2-7.
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