45 results about "Caesium fluoride" patented technology

The invention relates to a corrosion-free soldering flux used for braze welding aluminium and aluminium alloy. Counted by weight percentage, the soldering flux used for braze welding the aluminium and aluminium alloy comprises the following components: 32.0-34.0 percent of cesium fluoride, 44.0-46.5 percent of aluminium fluoride, 20.5-23.5 percent of potassium fluoride, 0.5-2.5 percent of one, two or three materials selected from tin fluoride, zinc fluoride and lithium fluoride. The corrosion-free soldering flux of the invention has low melting point and better soldering performance.

The invention discloses a synthesis method of 2,3-difluoro-5-chloropyridine, and the method comprises the following steps: in organic solvent, adopting 2,3,5-trichlopyridine and potassium fluoride as raw materials and tetraphenylphosphonium bromide or tetrabutylphosphonium bromide as phase transfer catalyst, keeping temperature at 180-190 DEG C for 5-10h under the protection of inert gas and keeping temperature at 200-210 DEG C for 10-15h to prepare 2,3-difluoro-5-chloropyridine. The synthesis method of 2,3-difluoro-5-chloropyridine of the invention adopts cheap and accessible potassium fluoride as fluorinating agent and adds phase transfer catalyst and controls the reaction temperature to prepare high yield 2,3-difluoro-5-chloropyridine, thus avoiding to use more expensive fluorinating agent such as caesium fluoride and the like and solving the defect that the yield of the reaction that potassium fluoride is directly used to perform fluorination is low. The method of the invention has simple operation and is applicable to the large-scale production of 2,3-difluoro-5-chloropyridine.

The invention relates to the field of brazing materials, in particular to a fluoride flux for copper-aluminum dissimilar metals and a preparation method thereof, which consists of cesium fluoride, aluminum trifluoride, potassium fluoride, copper difluoride and additives; Cesium fluoride, aluminum trifluoride, potassium fluoride, copper difluoride, zinc difluoride, lithium fluoride powder and zinc powder or ZnAl alloy powder are mixed in proportion, and an appropriate amount of deionized water is added and ground in a mortar until Paste, then dried and ground.

The invention discloses a preparation method of (S)-2-(adamantane-1-yl)-2-aminoacetic acid hydrochloride, wherein, comprising the following steps: firstly, 1-adamantanecarboxaldehyde and (S) ‑(‑)‑tert-butyl sulfinamide was dissolved in methylene chloride, then slowly adding dehydrating agent and pyridine p-toluenesulfonate, and reacted for 16 hours at a temperature of 20 ° C to obtain tert-butyl sulfinyl imide ; tert-butyl sulfenimide is dissolved in dichloromethane and tetrahydrofuran, trimethylnitrile silane and cesium fluoride are added, and the reaction is carried out at a temperature of 20 ° C for 16 hours to obtain cyanide; use a hydrolysis reagent to hydrolyze cyanide, First react for 6 hours at a temperature of 15°C, and then react at a temperature of 110°C for 16 hours to obtain the final compound, namely (S)-2-(adamantan-1-yl)-2-aminoacetic acid hydrochloride Salt, mainly to solve the technical problem that there is no suitable industrial synthesis method at present.

The invention discloses fluorescence-functionalized carbonate, having a structural formula that is shown in the description. The invention also discloses a method of preparing the fluorescence-functionalized carbonate. The method comprises the steps of dissolving trimethylolpropane-imidazole-carbonate and 2-(4-(1,2,2-triphenylvinyl)phenoxy)ethanol in acetone, reacting at 45-65 DEG C under the catalytic action of cesium fluoride, and isolating after full reaction to obtain the fluorescence-functionalized carbonate of formula I. The invention also discloses application of the fluorescence-functionalized carbonate in optical materials, and fluorescent polycarbonate prepared from the fluorescence-functionalized carbonate; as AIE (aggregation-induced emission) macromolecule, the fluorescent polycarbonate is applicable to the preparation of degradable bio-probes with adjustable fluorescent brightness.

The invention belongs to the field of fine chemicals and related chemical technologies, and provides a highly efficient preparation method of 1-aryl-4-butene compounds. Using halogen-containing methyl aromatic hydrocarbons and their derivatives as raw materials, in the presence of palladium catalysts and ligands, cesium fluoride as a base, under the condition of anhydrous organic solvents, and allylboronic acid pinacol ester at 80 ° C ~ 1-aryl-4-butene compound can be obtained by reacting at 100°C for 12 hours. The invention has the beneficial effects of high selectivity, mild reaction conditions, easy and convenient operation, the possibility of realizing industrialization, and obtaining 1-aryl-4-butene compounds in a relatively high yield; the 1-aryl-4-butene compound synthesized by the method is Aryl-4-butene compounds can be further functionalized to obtain various compounds, which are applied in the development and research of natural products, functional materials and fine chemicals.

The invention discloses a method for preparing 1,4 enyne compounds. In an inert gas atmosphere, allyl alcohol, alkynoic acid and a combined catalyst are added into an organic solvent, and the reaction is stirred at a temperature of 80-100° C. for 12-12 24h, a reaction solution was obtained; the combined catalyst was composed of organic palladium, fluoride salt and cesium fluoride, and the fluoride salt was bis-trifluoromethanesulfonimide salt or bis-trifluoromethanesulfonate; then the reaction solution was passed through water Extraction with ethyl acetate to remove part of the reaction solvent, drying and concentrating the organic phase, and purification by thin layer chromatography with petroleum ether / ethyl acetate developing solvent system to obtain 1,4-enyne compounds. The preparation method of the present invention is simple, the operation is convenient, the obtained by-products are only water and carbon dioxide, and has the characteristics of high atom economy and environmental protection; in addition, the preparation method of the present invention has low price of raw materials and a wide range of applicable substrates.

The invention provides a synthesis method of 1,1,2-trichloro-3-fluoropropylene, comprising the following step: in the presence of a polyalcohol solvent, carrying out a reaction on 1,1,2,3-tetrachloropropene and an alkali metal fluoride at 90-120 DEG C for 1.0-10h to obtain 1,1,2-trichloro-3-fluoropropylene. The molar ratio of the alkali metal fluoride to 1,1,2,3-tetrachloropropene is (1-5):1, wherein the alkali metal fluoride is sodium fluoride, potassium fluoride or cesium fluoride; and the polyalcohol is glycol, 1,2-propanediol, 1,3-propanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, tetraethylene glycol or glycerol. The synthesis method provided by the invention is mainly applied to preparing 1,1,2-trichloro-3-fluoropropylene.

The invention relates to the rust resistant method for aluminum coating of carbon steel part, aluminum soldering part and non aluminum soldering part, then installing aluminum part on the surface of the carbon steel part. Sending the assembled part into 200 deg.C-250deg.C drying oven, drying the compound soldering agent sufficiently, then taking into the controllable atmosphere oven for soldering and plating under the protection of the nitrogen, controlling the temperature within 570-615deg.C, soldering aluminum part on the surface of the carbon steel part, with the rest of the surface plated with aluminum, to finish the soldering and plating at one time, with the compound soldering material made of 30%-50% soldering material, 20%-40% soldering agent with the rest being ethandiol solution and the soldering material being Al. 85%-94%,Si: 15%-6%, the rest being microelement, the soldering material being aluminun fluoride 40-75%, and caesium fluoride 25-60%. It can be used to reduce the manufacturing cost.

The invention belongs to the technical field of ceramic materials, and in particular relates to a photocurable polysilazane and a preparation method thereof, SiCN ceramics and a preparation method thereof. In the present invention, by using 3-(trimethyloxysilyl)propyl methacrylate as a modifying agent, tetrabutylammonium fluoride, potassium fluoride and / or cesium fluoride are used as catalysts to Silazane is modified to activate the Si-H and N-H bonds of the branch chain under the condition of ensuring the polysilazane main chain is continuous, and then react with the modifier to introduce a photocurable group to obtain a photocurable polysilazane. Curing polysilazane, the photocurable polysilazane of the present invention can be combined with 3D photocuring molding to prepare complex shape embryos, and SiCN ceramics can be prepared after sintering.

The invention discloses a self-brazing material for welding an aluminum-copper member. The self-brazing material comprises the following components: 12-15 percent of fluoride (30-80 percent of aluminum fluoride, 5-35 percent of caesium fluoride and the balance of potassium fluoride), 0.01-0.3 percent of hafnium, 0.01-0.8 percent of germanium, 0.05-2 percent of nickel, 0.8-3 percent of copper, 5-17 percent of silicon and the balance of aluminum. The self-brazing material is prepared through the following steps of: smelting and atomizing the raw materials of hafnium, the germanium, the nickel, the copper, the silicon and the aluminum in a vacuum furnace into fine powder; and then uniformly mixing with the fluoride, pressing into a composite ingot, directly extruding the composite ingot into a yarn or pipe, and winding the yarn into a coil or cutting the pipe into a ring to obtain the self-brazing material. The self-brazing material disclosed by the invention has the advantages that trace elements of Ge and Hf are introduced on the basis of the traditional Al-Si-Cu-Ni alloy system brazing material, so that the brazing material smelting temperature is lowered, the burning loss of an aluminum base material during welding is favorably avoided, the strength and plasticity of the brazing material are improved, the mechanical property of a brazing joint is favorably improved, and the improvement of the plasticity of the brazing material can ensure that the production efficiency is increased.