46results about How to "Uniform crystal form" patented technology

The invention provides a freeze-dried preparation employing polymyxin E methanesulfinic acid sodium salt as an active component and a preparation method thereof. The preparation method of the polymyxin E methanesulfinic acid sodium salt includes following steps: adding polymyxin E methanesulfinic acid sodium salt to water, carrying out a stirring and dissolving process to obtain a polymyxin E methanesulfinic acid sodium salt solution, filtering the solution through a microporous filtration membrane to obtain a filtrate, and carrying out a freeze-drying process to obtain the freeze-dried preparation. The polymyxin E methanesulfinic acid sodium salt preparation is plump in appearance, is uniform in crystallization form and is easy to rehydrate. When a bottle of the preparation is rehydrated, the number of insoluble particles, which are not less than 10 [mu]m in particle sizes, is not more than 200.

The invention provides a process for preparing high dispersivity square blocky superfine magnesium hydroxide by a one-step method, which relates to a process for preparing a chemical material. The process comprises the following steps of: taking magnesium chloride as a raw material; preparing solution of the magnesium chloride; reacting the solution of the magnesium chloride with ammonia gas passed in at a certain speed rate in a bubbling reactor with stirring; controlling the stirring speed and the reaction temperature; and after the reaction, performing constant temperature aging, filtration washing and drying on reaction solution to obtain incompact square blocky (hexahedral structure) superfine magnesium hydroxide powder. An ammonium salt in filtrate can be used for preparing the ammonia gas used in the process of magnesium deposition through ammonia evaporation reactions so as to realize ammonia circulation. The process realizes a technique for synthesizing a magnesium hydroxide fire retarding agent through the one-step method at the normal temperature under a condition that no auxiliary agent is used. Besides, the process has good product quality, needs no hydro-thermal treatment, has simple operating steps, less equipment occupied area, low production cost and small pollutant discharge amount, and is suitable for large-scale production.

The invention relates to a method for electrochemical synthesis of Cu3 (BTC) 2 and belongs to the field of preparation technologies of catalytic material and nanometer material. The method comprises the following steps: preparing a mixed solution of 1-butyl-3 methylimidazole bromide, trimesic acid, methyl alcohol and ethyl alcohol, adopting a copper electrode as an anode and a platinum electrode as a cathode, and adjusting the impressed voltage through a mixed solution of EDTA and DETA for electrolysis to obtain the Cu3 (BTC) 2 material. According to the invention, the adopted raw materials are cheap and easy to obtain, the operation is simple and easy, the preparation method is simple and easy to control, the equipment requirements are low, the environmental friendliness is achieved, and the Cu3 (BTC) 2 material is of a regular octahedron structure and has a diameter of 10-20 nm and a specific area of 950 m<2>g<-1>; the test conditions of the reaction are as follows: 500 ppm of NO, 500 ppm of NH3, 5% of O2, N2 as balance gas, the total flow of exhaust gas being 100ml / min, and the denitration catalytic efficiency reaching 100% at 230-280 DEG C.

The invention discloses a preparation method of cefepime hydrochloride, comprising the following steps of: reacting oxalyl chloride with 2-methoxyimino-2-(2-aminothiazole-4-yl) acetic acid hydrochloride to obtain a midbody I, i.e. 2-methoxyimino-2-(2-aminothiazole-4-yl) acetyl chloride hydrochloride; mixing silanized 7-aminoce-phalosporanic acid and silanized N-methylpyrrolidine, and reacting to obtain a midbody II, i.e. hydriodic acidification (6R, 7R)-7-amino-3-[(1-methyl-1-tetrahydro pyrrolidine) methyl]-3-cephem-4-formic betaine, in the presence of trimethyl idodine silicon hydride, isopropanol and an aqueous solution of hydrogen iodide; dissolving the midbody II into dichloromethane, sequentially adding trimethylchlorosilane and hexamethyldisilazane for reaction, and then adding the midbody I and triethylamine to react to prepare the cefepime hydrochloride. The cefepime hydrochloride prepared by the method has the advantages of uniform crystal form, good flowability and simple process and is suitable for industrialized production.