Method of forming metallic oxide coatings upon siliceous support articles

Claim 1

THE METHOD OF FORMING ON THE SURFACE OF AN ARTICLE A CONTINUOUS COATING COMPOSED SUBSTANTIALLY COMPLETELY OF A HIGHLY OXIDIZED SOLID METALLIC OXIDE HAVING THE RELATIVELY HIGH LIGHT TRANSMISSION CHARACTERISTICS NORMAL TO SUCH HIGHLY OXIDIZED SOLID METALLIC OXIDE, COMPRISING PROVIDING ON A HEAT RADIATING SUPPORT BODY A METALLIC OXIDE OF A METAL CAPABLE OF FORMING OXIDES OF A PLURALITY OF DIFFERENT OXIDATION STATES, THE METAL BEING SELECTED FROM THE GROUP CONSISTING OF ALUMINUM, TITANIUM, CHROMIUM, TIN, ZIRCONIUM, ANTIMONY, IRON, TANTALUM, TUNGSTEN AND MANGANESE, HEATING THE SUPPORT BODY ADJACENT THE SURFACE OF THE ARTICLE IN A VACUUM AND THEREBY HEATING THE METALLIC OXIDE TO EVAPORATE METALLIC OXIDE AND DEPOSIT UPON THE SURFACE A CONTINUOUS AND LIGHT ABSORBING METALLIC OXIDE COATING COMPRISING A METALLIC OXIDE OF LOWER OXIDATION STATE AND HIGHER LIGHT ABSORPTION THAN THAT OF THE SAID HIGHLY OXIDIZED SOLID METALLIC OXIDE, TERMINATING DEPOSITION OF SAID COATING BEFORE SAID COATING ATTAINS A THICKNESS WHICH WOULD RENDER THE COATING OPAQUE WHEN SUBSTANTIALLY COMPLETELY OXIDIZED TO SAID HIGHLY OXIDIZED STATE, AND THEREAFTER ALTERING THE OPTICAL PROPERTIES OF SAID COATING TO INCREASE ITS LIGHT TRANSMISSION CHARACTERISTICS BY SUBSTANTIALLY COMPLETELY OXIDIZING THE OXIDE OF LOWER OXIDATION STATE BY SUBJECTING THE COATING TO AN ATMOSPHERE HAVING A PARTIAL PRESSURE OF OXYGEN OF AT LEAST 50 MM. OF MERCURY, AND WHILE SUBJECTING SAID COATING TO SAID ATMOSPHERE HEATING SAID COATING TO A TEMPERATURE ABOVE 200 DEGREES CENTIGRADE SUFFICIENT TO OXIDIZE THE PARTICULAR OXIDE OF LOWER OXIDATION STATE TO FORM A COATING COMPOSED SUBSTANTIALLY COMPLETELY OF SAID HIGHLY OXIDIZED SOLID METALLIC OXIDE.

Claim 2

THE METHOD OF FORMING ON THE SURFACE OF AN ARTICLE A CONTINUOUS COATING COMPOSED SUBSTANTIALLY COMPLETELY OF A HIGHLY OXIDIZED SOLID METALLIC OXIDE HAVING THE RELATIVELY HIGH LIGHT TRANSMISSION CHARACTERISTICS NORMAL TO SUCH HIGHLY OXIDIZED SOLID METALLIC OXIDE, COMPRISING PROVIDING ON A HEAT RADIATING SUPPORT BODY A METALLIC OXIDE OF A METAL CAPABLE OF FORMING OXIDES OF A PLURALITY OF DIFFERENT OXIDATION STATES, THE METAL BEING SELECTED FROM THE GROUP CONSISTING OF ALUMINUM, TITANIUM, CHROMIUM, TIN, ZIRCONIUM, ANTIMONY, IRON, TANTALUM, TUNGSTEN AND MANGANESE, HEATING THE SUPPORT BODY ADJACENT THE SURFACE OF THE ARTICLE IN A VACUUM AND THEREBY HEATING THE METALLIC OXIDE TO EVAPORATE METALLIC OXIDE AND DEPOSIT UPON THE SURFACE A CONTINUOUS AND LIGHT ABSORBING METALLIC OXIDE COATING COMPRISING A METALLIC OXIDE OF LOWER OXIDATION STATE AND HIGHER LIGHT ABSORPTION THAN THAT OF THE SAID HIGHLY OXIDIZED SOLID METALLIC OXIDE, TERMINATING DEPOSITION OF SAID COATING BEFORE SAID COATING ATTAINS A THICKNESS WHICH WOULD RENDER THE COATING OPAQUE WHEN SUBSTANTIALLY COMPLETELY OXIDIZED TO SAID HIGHLY OXIDIZED STATE, AND THEREAFTER ALTERING THE OPTICAL PROPERTIES OF SAID COATING TO INCREASE ITS LIGHT TRANSMISSION CHARACTERISTICS BY SUBSTANTIALLY COMPLETELY OXIDIZING THE OXIDE OF LOWER OXIDATION STATE BY SUBJECTING THE COATING TO AN ATMOSPHERE HAVING A PARTIAL PRESSURE OF OXYGEN OF AT LEAST 50 MM. OF MERCURY, AND WHILE SUBJECTING SAID COATING TO SAID ATMOSPHERE HEATING SAID COATING TO A TEMPERATURE ABOVE 200 DEGREES CENTIGRADE SUFFICIENT TO OXIDIZE THE PARTICULAR OXIDE OF LOWER OXIDATION STATE TO FORM A COATING COMPOSED SUBSTANTIALLY COMPLETELY OF SAID HIGHLY OXIDIZED SOLID METALLIC OXIDE.