Abstract: A cost-reduced fluorescent lamp having an electrically conductive first layer carried on the inner surface of a vitreous envelope and an electrically non-conductive second layer carried on the electrically conductive first layer. The electrically non-conductive second layer is a mixture of very finely-divided aluminum oxide and finely-divided titanium dioxide in predetermined relative weight ratio.

Abstract: Fluorescent lamp incorporates tin oxide conductive coating on the envelope interior surface and the lamp also incorporates phosphor means comprising manganese-activated zinc silicate phosphor, which may be used as a blend constituent. The lamp is processed in such a manner as to improve the performance of the zinc silicate phosphor. In order to improve the adherence of the phosphor to the tin oxide conductive coating, the tin oxide is overcoated with a film of sub-micron-size aluminum oxide and, in accordance with the present processing, there is included with the aluminum oxide finely divided antimony oxide. The phosphor is then overcoated onto the mixed film of aluminum oxide and antimony oxide, and during the later lehring processing of the coated phosphor, the antimony oxide is volatilized to contact the zinc silicate phosphor to improve the performance thereof.

Abstract: A method of preparing anhydrous dicalcium orthophosphate of predetermined and substantially uniform particle size for use in making fluorescent lamp phosphors. The method entails heating an acidified aqueous slurry of hydrated dicalcium orthophosphate in a reaction vessel and at the same time agitating the heated slurry. The heating and simultaneous agitation is continued until significant incipient formation of a gel-like material is manifested at the wall portions of the reaction vessel. At that point the application of heat to the slurry is discontinued. The agitation of the slurry within the vessel is continued until all the slurry is converted to meta-stable gel-like material. At that time the agitation is discontinued. The formed meta-stable gel-like material is then maintained in a quiescent state until it converts completely to crystals of dicalcium orthophosphate. The orthophosphate crystals are then permitted to settle to the bottom of the residual liquid in the vessel.

Abstract: A method of producing finely-divided phosphor grade calcium carbonate having a calcite crystalline structure and a very low sodium content. The calcium carbonate is produced from calcium chloride having a high sodium impurity content, such as calcium chloride which is a by-product of the Solvay process for producing soda ash.