15results about How to "Prevent self-aggregation" patented technology

The invention discloses a preparation process of berberine hydrochloride, and belongs to the technical field of berberine production. The invention relates to a berberine hydrochloride preparation process, which comprises: S1, mixing a ferric sulfate-aluminum sulfate composite salt, sodium chloride, zinc chloride and anhydrous formic acid, pre-activating, adding N-2, 3-dimethoxybenzyl homopiperony lamine hydrochloride, dropwise adding a glyoxal mixed solution, and carrying out a reflux reaction. And S2, cooling the reaction liquid until a solid is separated out, filtering, adding a filter cake and diatomite into purified water, stirring, adjusting alkali, heating, and continuously stirring for 0.5-1 hour. Cooling and filtering, and reserving filtrate; s3, adjusting the acidity of the filtrate, cooling and growing crystals; and filtering, rinsing a filter cake, and carrying out vacuum drying on the filter cake to obtain berberine hydrochloride. The berberine hydrochloride prepared by the method is high in yield and purity, and the preparation process is safe, short in flow and friendly to human bodies and environment.

The application discloses a method for continuously preparing high-purity sulfolane, and belongs to the technical field of organic synthesis. By introducing a solvent and a stable free radical type polymerization inhibitor, the self-polymerization of butadiene is effectively inhibited. By adopting a cooling crystallization mode to remove sulfur dioxide, the thermal decomposition of sulfolene sulfone is avoided, high yield and high purity are realized, the service life of a hydrogenation catalyst is not affected, and the catalyst can be completely reused. The cooling crystallization also realizes the separation of the polymerization inhibitor and sulfolene sulfone. The polymerization inhibitor is dissolved in the solvent and recycled, and does not enter the hydrogenation system, so that the final sulfolane product has a purity of above 99.9% and has no chromaticity problem. The process saves energy consumption, the solvent has wide universality, operation is simple, the process is safe and environment-friendly, easy to scale up, and meets the green production requirements.

The invention relates to the technical field of medical instruments, in particular to a heparin coating based on material surface ammonification modification and a preparation method thereof, and the preparation method at least comprises the following steps: carrying out ultrasonic pretreatment on a base material with purified water, and drying for later use; the preparation method comprises the following steps: performing amination modification on a base material subjected to ultrasonic pretreatment by adopting an ammoniation reagent solution, and immersing the base material into a heparin solution to prepare the base material with a heparin coating on the surface. The surface of the material is subjected to amination modification by adopting a micromolecular ammoniation reagent and / or a macromolecular ammoniation reagent system, complex pretreatment such as plasma and ultraviolet rays does not need to be carried out on a base material, specific functional group activation does not need to be carried out on heparin, and the heparin is directly reacted after being subjected to ammoniation modification; the stable covalent grafted heparin anticoagulation coating can be formed, the anticoagulation time is prolonged, and the long-term implantation requirement is met.

The utility model provides a magnetic turning plate liquid level meter with an anti-self-gathering device, which comprises a liquid level meter body pipe, an upper connecting flange, a lower connecting flange, a magnetic turning plate indicator and a maglev, and the upper connecting flange and the lower connecting flange are respectively arranged on protruding connecting pipes at the bottom and the top of the side wall of the liquid level meter body pipe. A magnetic levitation element is arranged in a pipe body of the liquid level meter body pipe, a magnetic turning plate indicator is installed on the side wall of the liquid level meter body pipe, an anti-self-gathering device is arranged at the bottom of the liquid level meter body pipe, an impeller working pipe slightly smaller than the liquid level meter body pipe is additionally arranged on the lower portion of the liquid level meter body pipe, and a stirring impeller is installed in the impeller working pipe. And the lower part of the working pipe of the impeller is connected with a pipeline and a circulating pump, so that the liquid circularly enters the storage tank to be detected. A polymerization inhibitor injection point is added at the upper connecting flange, a polymerization inhibitor is mixed with liquid in the liquid level meter through stirring and then enters a storage tank through a circulating pipeline, a blind area of the liquid level meter is eliminated, and a measured medium is prevented from self-polymerization in the liquid level meter.

The present application relates to a kind of methyl tetrahydrophthalic anhydride continuous production process and device, the present application adopts piperylene segmented feed, isoprene is first with a part of piperylene and maleic anhydride pre-synthesis reaction at low temperature, then continue to react with another part of piperylene at higher temperature, reduce isoprene self-polymerization, using column tube heat exchanger to improve synthesis efficiency, heater and mixer are set on external circulation pipeline to carry out temperature control to reactor, using the method that reactor synthesis product carries fresh raw material and circulates into reactor to prevent fresh carbon five and anhydride aggregation self-polymerization to reduce side reaction, no high polymer slag is generated.

The application relates to a CMP composition for obtaining a high-quality SiC single crystal substrate surface, which is prepared from the following raw materials in percentage by weight: 20-50 wt% of polishing abrasive, 3-5 wt% of oxidizing agent, 0.1-0.5 wt% of surfactant, 0.2-0.5 wt% of hydrogen bond regulator, 0.2-1 wt% of polishing accelerator, 0.01-0.05 wt% of defoaming agent, and the balance of water; the CMP composition is neutral. The CMP composition uses silicon oxide as the abrasive, introduces the hydrogen bond regulator, the polishing accelerator and the oxidizing agent, improves the polishing rate of the silicon carbide wafer CMP, realizes that the surface roughness Ra of the silicon surface after cleaning can reach below 0.07 nm, the surface after cleaning is free of large particles (>0.2 um), meanwhile, the silicon oxide raw material does not need to be treated, has excellent long-term storage stability, and the system does not have the phenomena of particle agglomeration and sedimentation with the prolongation of the storage time, and excellent polishing surface quality can be obtained in the subsequent polishing process.

The invention relates to the technical field of AP (ammonium perchlorate) modification, in particular to a preparation method of an ammonium perchlorate anti-moisture-absorption material coated with silicon dioxide based on double-silane synergistic modification through a wet method. Silicon dioxide is subjected to two-step synergistic modification through a long-chain alkylsilane modifier and a short-chain alkylsilane modifier; the preparation method comprises the following steps: modifying the surface by using long-chain silane, filling long-chain silane modified gaps by using short-chain alkyl to prepare modified nano silicon dioxide particles, and coating superfine AP particles with the modified nano silicon dioxide particles through wet modification, the modified nano silicon dioxide particles have enough steric hindrance and better hydrophobicity due to a three-dimensional structure on the surface, and the AP can be effectively prevented from being agglomerated after being coated with the modified nano silicon dioxide particles; the method is green and pollution-free, the process is simple, the comprehensive performance can be easily controlled through simple adjustment, the problem that the ultra-fine AP particles produced industrially are prone to moisture absorption and caking can be solved, and the application range of the ultra-fine AP particles in novel high-energy propellants is widened.

The invention provides a vacuum self-aggregation prevention ball valve, belongs to the technical field of valves, and solves the technical problem that a conveying medium in a valve is easy to enter an assembly gap to generate a self-aggregation phenomenon. Comprising a main valve body, an auxiliary valve body, a ball core and a valve seat, the main valve body and the auxiliary valve body are oppositely combined and connected to form a valve shell, the medium channel is provided with a spherical cavity section, annular diameter expanding sections are arranged on the two sides of the spherical cavity section respectively, and the valve seat is annular and installed on the annular diameter expanding sections. The ball core is also provided with a penetrating medium channel, a valve rod of the ball core penetrates out of the valve shell, a first sealing structure is arranged at the matching position, and the ball core is installed on the spherical cavity section and at least comprises a full-open state and a full-closed state. A second sealing structure is arranged on the mounting face of the valve seat and the annular expanding section, a third sealing structure in sliding contact with the ball core is arranged at the end, facing the ball core, of the valve seat, a containing cavity is formed between the ball core and the valve shell, and a communicating pipe is arranged outside the containing cavity and the valve shell. The valve has the technical effects of preventing a medium from entering an assembly gap to form a self-aggregation phenomenon and improving the operation stability of the valve.

The invention relates to the field of outdoor materials, and particularly discloses a preparation method of a hydrophilic PVDF (polyvinylidene fluoride) membrane, which comprises the following steps: S1, carrying out acidolysis chain scission on native starch to refine into a small molecular starch chain, and then carrying out grafting reaction on the small molecular starch chain and a grafting monomer to obtain a starch grafting monomer; s2, the starch grafting monomer and PVDF are subjected to melt grafting modification, and PVDF grafting modified master batches are obtained; and S3, carrying out granulation modification on PVDF, PMMA, the PVDF grafted modified master batch and a plurality of auxiliary agents, and then carrying out tape casting to obtain the PVDF hydrophilic functional film. According to the invention, the grafting monomer and the starch are firstly modified, so that not only can hydrogen bonds among the starch be broken, but also the starch can be fixed on the grafting monomer, and then the grafting monomer is grafted to the main chain of the PVDF by adopting a melt extrusion grafting method, so that the hydrophilicity and the stability of the PVDF can be greatly improved. The problem of insufficient hydrophilicity of the PVDF membrane in the prior art is solved.

This invention provides a method for modifying inorganic powder, modified inorganic powder, and a carrier insulating film. The modification method includes the following steps: (1) drying the inorganic powder; (2) mixing a silane coupling agent with an alcohol solvent, adding deionized water while stirring, and continuing to stir to obtain a silane hydrolysate; (3) spraying the silane hydrolysate obtained in step (2) onto the inorganic powder obtained in step (1) while it is being stirred, heating, and stirring to react, thereby obtaining the modified inorganic powder. The modification method provided by this invention constructs a dense organic molecular layer on the surface of the inorganic powder that is chemically compatible with the resin matrix through a stepwise and controllable process, thereby significantly improving the dispersibility of the inorganic powder in the resin, reducing the viscosity of the slurry, and enhancing the dielectric properties and reliability of the final composite material.

This invention relates to the field of semiconductor packaging materials technology, specifically disclosing a low-dielectric filler for packaging chips and its preparation method. The invention uses fluorosilicone-modified benzoxazine, fluorosilicone-modified alicyclic epoxy resin and dicyclopentadiene cyanate prepolymer crosslinking to form a low-viscosity polymer, and then adds low-dielectric filler F-mesoporous SiO2 and functional additives. The resulting low-dielectric filler has low viscosity, can fill ultrafine gaps well, and after curing, the filler has low volume shrinkage and good high-frequency dielectric properties.

This invention relates to a method for synthesizing polyether macromonomers for polycarboxylate superplasticizers with high double bond retention. The method uses methyl allyl alcohol as an initiator, potassium hydroxide as a catalyst, and propylene oxide (PO) and ethylene oxide (EO) as comonomers, synthesizing the polyether macromonomers for polycarboxylate superplasticizers via block copolymerization. The invention employs a zero-pressure + nitrogen-protected feeding process to effectively prevent EO molecules from colliding and self-polymerizing, thus reducing the double bond retention rate. The use of trace amounts of catalyst in the synthesis process avoids the damage to unsaturated double bonds caused by alkaline catalysts. Limiting the reaction pressure range reduces the number of EO molecules in the reactor per unit time, thereby reducing the probability of EO molecules colliding. Applying this polyether to superplasticizers can significantly improve their water reduction rate, improve the fluidity of cement paste, and enhance slump retention. The polyether macromonomers synthesized using this method have a double bond retention rate as high as 99%.

The present application is a kind of catalyst and process for preparing electronic grade propionic acid ester by hydrogenation of acrylic acid ester. The process uses activated carbon supported Ni-based catalyst, and one or two of Re, B or Ag as additives. The process is to mix acrylic acid ester containing trace amount of polymerization inhibitor or mixture with corresponding propionic acid ester with hydrogen and preheat into gas phase, then enter the fixed bed reactor containing catalyst to carry out gas phase reaction under very mild conditions, which avoids problems such as raw material self-polymerization and catalyst sintering, the catalyst can be stably operated for more than 2000 hours, the conversion rate of acrylic acid ester and the selectivity of propionic acid ester still maintain nearly 100%, which shows excellent stability, the purity of propionic acid ester in the reactor outlet sample can reach more than 99.6%, therefore, electronic grade propionic acid ester product can be obtained by simple rectification and molecular sieve dehydration treatment.

This invention relates to the field of new chemical materials technology for hydraulic engineering, specifically to a fluorinated isocyanate, its preparation method, and its application. The method involves heating isocyanate and hexafluorobisphenol A under the action of a catalyst to carry out an addition reaction; the molar ratio of isocyanate groups in the isocyanate to the hydroxyl groups in hexafluorobisphenol A is greater than 1.7; the catalyst is an organotin catalyst, an organobismuth catalyst, or an organozinc catalyst. This method uses "hard-segment fluorination" to control the excess isocyanate and prevents explosive polymerization through staged feeding and strict temperature control, resulting in a homogeneous liquid product with low viscosity, high fluorine content, and both low surface energy and high mechanical strength. This method solves the problems of high water absorption rate in polyurea and high viscosity and embrittlement in fluorinated modified materials. The obtained product can be used to prepare fluorinated modified polyurea materials for surface water sealing, seepage prevention, and ice prevention in pumped storage power station dam panels, solving the technical problems of ice prevention, seepage prevention, and poor durability under harsh environments such as long-term water immersion in hydraulic engineering.

This invention relates to the field of solar cell technology, specifically to a hole transport layer containing betaine hydrochloride additive and its inverse wide-bandgap perovskite solar cell. The hole transport layer comprises a nickel oxide layer and a self-assembled molecular layer formed on its surface. The self-assembled molecular layer contains (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid and betaine hydrochloride. The introduction of betaine hydrochloride improves the conductivity of the hole transport layer through the interaction of its carboxylic acid groups with nickel oxide, and inhibits its clustering behavior through interaction with the self-assembled molecules, thereby improving film uniformity and effectively passivating buried interface defects in the perovskite light-absorbing layer. The inverse wide-bandgap perovskite solar cell fabricated based on this hole transport layer exhibits significantly improved open-circuit voltage and fill factor, ultimately achieving a photoelectric conversion efficiency exceeding 21.7%. This invention provides an effective interface engineering strategy for fabricating efficient and stable wide-bandgap perovskite solar cells and tandem devices.