30results about How to "Control joining speed" patented technology

The invention provides a method for preparing 3-(2-Chloroethyl)-2-methylpyrido[1,2-a]pyrimidin-4-one. The method uses 2-aminopyridine and 2-acetylbutyrolacton as raw materials and comprises steps of reactants preparation and separation and purification. The reactants are prepared by the following steps of: placing the 2-aminopyridine and the 2-acetylbutyrolacton into toluene, mixing and stirring the mixture to obtain a reactant liquid, heating the reactant liquid, diluting phosphorus oxychloride with the toluene in advance, dripping the diluted phosphorus oxychloride into the liquid, keeping the temperature at 110 DEG C, carrying out reflux, and obtaining the reactants. The invention can well control the dripping speed of the phosphorus oxychloride, thereby solving the problems of multiple solvents and complex operation caused by ammonia, methylene dichloride, isopropanol, etc. in the following operation, simplifying the process of separation and purification, improving the product yield, and achieving the pure product rate of more than 70 percent.

The invention relates to a method for preparing micro-nano silver particles in an aqueous solution system, comprising the following steps: mixing an aqueous silver salt solution with an aqueous solution of a complexing agent to obtain a silver complex precursor solution, and then adding and mixing the aqueous solution of a reducing agent simultaneously to carry out One-step reduction reaction to obtain micronano silver particles. The invention reacts in aqueous solution under normal temperature and pressure, does not use high molecular polymer as protective agent and dispersant, and uses hydrazine hydrate as reducing agent to reduce silver complex precursor. The preparation method is simple, avoids the residue of the high molecular polymer on the surface of the silver powder, and the prepared flower-shaped micro-nano silver particles have regular appearance, uniform particle size distribution, good dispersibility, controllable size and high yield.

The application discloses a spherical silver powder with a controllable particle size distribution, a preparation method and application thereof, and belongs to the technical field of silver powder preparation. The silver powder includes a first silver powder, a second silver powder and a third silver powder, and the particle size ranges of the first silver powder, the second silver powder and the third silver powder are respectively 2.7-5 μm, 0.3-0.7 μm and 0.8-2.5 μm, so The mass fraction of the first silver powder is 5% to 20%, and the mass fraction of the second silver powder is 5% to 25%. This kind of spherical silver powder has a wide range of particle size distribution, is composed of particles of different particle sizes, and has micron, submicron and nano-scale silver powder at the same time, with high tap density, large specific surface area and uniform dispersion. It has a broad application prospect in the field of electronic pastes such as silver paste for solar cells and / or electrode silver paste for electronic components.

The application relates to the technical field of disinfection products, and specifically discloses a stable disinfectant and a preparation method thereof. The stable disinfectant is formed by mixing A liquid and B liquid, and includes the following raw materials by weight: A liquid: food-grade fatty acid 6-15 parts; 20-30 parts of lactic acid; 1-4 parts of stabilizer; 8-14 parts of citric acid; 15-25 parts of deionized water; stabilizer is composed of sucrose fatty acid ester and alkyl sulfonate, sucrose fat The weight ratio of acid ester and alkyl sulfonate is 1:(1-3); B liquid: 3-5 parts of cinnamon essential oil; 10-15 parts of ethanol; 0.5-1 part of cyclodextrin; 20-40 parts of deionized water The preparation method is as follows: mixing food-grade fatty acid, lactic acid, citric acid and deionized water, adding stabilizer and mixing evenly after mixing to obtain A liquid; after mixing ethanol and cinnamon essential oil evenly, adding cyclodextrin and deionized water The ionized water is mixed evenly to obtain the B liquid; the stable disinfectant is obtained after the A liquid and the B liquid are mixed evenly; the stable disinfectant of the present application has the advantage of good stability.

The invention discloses a preparation method of polyvinylamine. In the method, degradation reactions including chlorination, a rearrangement reaction, separation and purification are undergone on polyacrylamide serving as a raw material. In the chlorination, a nonionic surfactant is added into a mixed solution of sodium hydroxide and sodium hypochlorite, polyacrylamide serving as the raw materialis added in batches at the temperature between 10 DEG C below zero and 0 DEG C for reacting for 1 hour by stirring, and the dosage of the surfactant is 3-5 percent by weight of the weight of the raw material. In the rearrangement reaction, chlorination mixed liquor is slowly added into a sodium hydroxide solution with the concentration of 20-50 percent by mass at the temperature between 10 DEG C below zero and 0 DEG C at the speed between 15 millimeters per minute and 35 millimeters per minute for reacting for 5-8 hours by stirring, and at least 5 times of excessive alkali liquor is used according to the mass of polyvinylamine serving as the raw material. By adopting the nonionic surfactant in the method, the surface tension of the solution is lowered, stretching of a main chain is promoted, an amido group is fully shown and is fully chlorinated in time, and hydrolysis is reduced. Meanwhile, an alkali-containing mother liquor can be recovered and reused.