234 results about "Magnesium bromide" patented technology

Provided is a metal halide lamp capable of being dimmed, which is prevented from non-lighting due to leakage of an arc tube attributable to a crack occurring at thin tubes, as well as realizing a desired color characteristic. The metal halide lamp has an arc tube that includes an envelope made of translucent ceramic, a pair of electrodes, and metal halides, the metal halides including rare earth metal halide, sodium halide, and magnesium halide, the rare earth metal halide being at least one of dysprosium halide, thulium halide, holmium halide, cerium halide, and praseodymium halide, and the magnesium halide being at least one of magnesium iodide and magnesium bromide, where when a maximum lamp power P (W) is in a range of 70 W to 250 W, the following relations are satisfied:0.0345A+0.0028B<0.0015 P+0.0475;A≧0.021P+0.313; andB≧10.0,where A (mg) represents a total content of the metal halides, and B (mol %) represents a content ratio of the magnesium halide to the metal halides.

The invention discloses a preparation method of 2,3,5,6-tetrafluoro-p-methylbenzyl alcohol, which belongs to the preparation technology of 2,3,5,6-tetrafluoro-p-methylbenzyl alcohol. The method is prepared by taking 2,3,5,6-tetrachloroterephthaloyl chloride as a raw material through fluorination, esterification, reduction, bromination and reduction. The fluorinating agent of the fluorination reaction is potassium fluoride, etc., the solvent is sulfolane, etc., the catalyst is calixarene, etc., and the reaction temperature is 40°C-230°C. Esterification The esterification agent is aliphatic alcohol or aromatic alcohol, and the reaction temperature is 20°C to 120°C. Reduction reaction of ester The reducing agent is sodium borohydride, etc., the solvent is sulfolane, etc., and the reaction temperature is -10°C to 60°C. The bromination agent for the bromination reaction is HBr acid, the solvent is dichloromethane, and the reaction temperature is 30°C to 160°C. The reducing agent of the bromide reduction reaction is magnesium powder, etc., the solvent is fatty alcohol, water, chloride, etc., and the reaction temperature is -10°C to 50°C. The invention has the advantages of simple process, low production cost, high product yield and purity, and is suitable for industrialized production.