188results about How to "Reduce the content of metal ions" patented technology

The invention relates to a preparation method for 4, 4'-diamino diphenyl ether, which comprises: taking catalytic hydrogenation reduction reaction to the 4, 4'-dinitro diphenyl ether in alcohol solvent; crystallizing to obtain the coarse product; reducing pressure to sublimate and refine the coarse product for final product. This invention has well product quality and no pollution with low cost, and more fit to spread than the traditional ferrous powder-chlorhydric acid reduction method.

The invention relates to a continuous production method of high-purity hydrochloric acid; the continuous production method is carried out by chemically dechlorinating, rectifying at normal pressure, filtering in a circulating manner, decompressing and rectifying by taking industrial hydrochloric acid as the raw material; in the event of decompressing and rectifying, the pressure in a decompressing and rectifying kettle is controlled within 25-95 KPa; the reflux ratio is 1:(1.8-2.5); and various processes in the process are carried out sequentially and continuously. According to the invention, high-purity hydrochloric acid achieving the SEMIC12 semiconductor grade requirements can be produced environmentally, efficiently and continuously through the four simple steps; in the obtained hydrochloric acid product, the content of single metal ion can be reduced to be below 50 ppt; the content of anion can be reduced to be below 50 ppb; and the content of free chlorine can be reduced to be below 300 ppb. An online control technology and a totally-enclosed purified production manner provided by the invention are further combined, therefore, hydrochloric acid products having steady quality can be produced reliably for a long time; and long-term, large-batch and steady specific requirements in the semiconductor industry are satisfied.

A process for preparing high-purity calcium carbonate used as insulating filler and crystal grain fining agent in electronic industry includes such steps as providing Ca-contained compound and SO4 radical contained compound, multi-step depositing for removing impurities, synthesizing reaction to generate deposit, washing and drying.

The invention discloses a preparation method of 2,2-bis(3-amino-4-hydroxylphenyl)hexafluoropropane, belonging to the technical field of electronic chemical materials. The preparation method comprisesthe following steps: adopting 2,2-bis(3-nitro-4-hydroxylphenyl)hexafluoropropane as raw material and hydrazine hydrate dissolved in methanol as reductant to reduce 2,2-bis(3-nitro-4-hydroxylphenyl)hexafluoropropane under the action of catalyst CeO2-SnO and obtain raw 2,2-bis(3-amino-4-hydroxylphenyl)hexafluoropropane, using chelating agent to remove metal ions in the raw product and performing vacuum sublimation and purification to the obtained 2,2-bis(3-amino-4-hydroxylphenyl)hexafluoropropane in which metal ions are removed and finally obtaining the target product. The method has low production cost, high product purity, low contents of metal ions and high yield.

The invention discloses cleaning fluid, which comprises at least an oxidizer, at least a carbamidine compound and water. The invention further discloses application of the cleaning fluid in cleaning wafer after the wafer is polished chemically and mechanically. The cleaning fluid can clean polishing particles and chemical substance remaining on the surface of wafers after being polished chemically and mechanically. In addition, the cleaning fluid contains few metallic ions and is odorless, thus reducing pollution of metallic ions and environmental pollution.

The invention discloses a polyphenylene sulfide resin synthesis process, which aims to obtain a resin synthesis method with good particle formation, high product yield, high solvent recovery rate, andreduced corrosion degree of a polymerization reaction device. The method adopts sodium sulfhydrate containing sodium crystallization, sodium hydroxide, and p-dichlorobenzene as raw materials, and takes N-methylpyrrolidone as a solvent, and a condensation polymerization reaction is carried out in a synthesis system, after the low temperature and high temperature polycondensation is completed, acetate, NMP and an aqueous solution are added by a high-pressure pump, then the materials are insulated at a high temperature, cooled, and filtered, and a filter cake is purified by a NMP solvent, repeatedly washed with deionized water and filtered, and the filter cake is dried to obtain the polyphenylene sulfide resin. The polyphenylene sulfide resin synthesized by the invention is widely used in the fields of aerospace, electronic machinery, petrochemical, food, light industry, thermal power generation, cement industry, steel manufacturing, environmental protection, textile industry and the like.

The invention discloses a method for preparing polyphenyl ether with a side chain containing an unsaturated carbon-carbon double bond in a water medium. The method comprises the following steps of: carrying out oxidative copolymerization reaction on a common phenol monomer and a phenol monomer containing the unsaturated carbon-carbon double bond in the water medium at 30-60 DEG C for 4-24 hours in the presence of a catalyst, a surfactant, an alkali compound and an oxidant; and after the oxidative copolymerization reaction is finished, carrying out demulsification, filtering and washing to obtain the polyphenyl ether with the side chain containing the unsaturated carbon-carbon double bond. The polyphenyl ether containing the unsaturated carbon-carbon double bond prepared in the water medium according to the method disclosed by the invention has the characteristics of low residual metal catalyst content, low dielectric constant, low medium loss, organic solvent resistance, high temperature resistance, good processing performance and the like; and the preparation process is green, environment-friendly, simple, convenient, and easy to implement, safe and nontoxic, has wide development space and great market application value, and is in line with the requirements of sustainable development.

The invention relates to a processing method for improving the stability of a terbutaline sulfate injection. The processing method comprises the following steps: S1, passivating a stainless steel preparation tank and a pipeline by using nitric acid of 8 wt% before preparing the terbutaline sulfate injection, wherein the passivating temperature is 49 DEG C to 52 DEG C, the passivating time is 0.5-2hours; washing with water for injection until the pH is 5.0-7.0; S2, putting the pipeline passivated by the terbutaline sulfate injection prepared through the passivated stainless steel preparation tank in a glass bottle under the protection of nitrogen, and sterilizing, wherein the inner surface of the glass bottle is modified by an active group, and the active group is one or more of amino, sulfydryl, carboxyl and anhydride. The stability of the terbutaline sulfate injection is greatly improved through passivating and silanization, so that the content of the terbutaline sulfate is kept stable before and after filling and in the long-term storage process.

The invention provides a synthetic method of water insoluble polyether synthetic base oil and relates to a synthetic method of a chemical industry product. The synthetic method comprises the following steps of: firstly preprocessing n-butyl alcohol, throwing 10-20g of 3A molecular sieve into per kg of n-butyl alcohol, stirring to be uniform, placing for 24 hours, filtering out the molecular sieve, then throwing into the same fresh molecular sieve, and repeating the steps for three times for later use; then sequentially throwing the n-butyl alcohol and a multi-metal catalyst in a reaction kettle, carrying out an initiation reaction, slowly dropwise adding epoxypropane into the reaction kettle, after dropwise adding is finished, discharging when the temperature of the reaction kettle is reduced to 60 DEG C, thus obtaining an intermediate; and finally throwing the intermediate into the reaction kettle, slowly dropwise adding mixture of the epoxypropane and ethylene oxide into the reaction kettle, after dropwise adding is finished, discharging when the temperature of the reaction kettle is reduced to 60 DEG C, and filtering, thus obtaining a finished product. The polyether synthetic base oil prepared by the synthetic method disclosed by the invention has the advantages of high viscosity property, high viscosity index, small variation along with temperature, low flow point and freezing point, stronger lipophilicity, good intermiscibility with various penetrants, better oxidation stability and emulsion performance and certain water-retaining property.

A process for quickly growing the large-diameter monocrystal of potassium dihydrogen phosphate by solution temp lowering method features that the consumptions of potassium chloride and EDTA are respectively 1-5 M% and 0.01-0.02 Wt%, the initial over-saturation is 8 deg.C for maximum, and the temp lowering speed is 0.3-0.5 deg.C per day for initial growing stage and 2 deg.C per day for fast growing stage.

The invention discloses a method for purifying an organic amine electroplating additive. Anion and cation impurities in the organic amine electroplating additive are eliminated by using an electric deionization device; end plates are respectively arranged on two ends of the electric deionization device; cathodes and anodes which are connected with a direct-current power supply are respectively arranged on the end plates; a plurality of purifying chambers and concentrated water chambers are sequentially and alternatively arranged in parallel between two end plates; each purifying chamber and the concentrated water chamber are respectively isolated from each other through cation exchange membranes or anion exchange membranes; the purifying chambers are filled with ion exchange resin; the concentrated water chamber and an electrode water chamber are respectively filled with 0.3-1% organic ammonium salt solutions; the flow of the purifying chamber is 1-100L / h; the flows of the concentrated water chamber and the electrode water chamber are 1-100L / h; the voltage of the direct-current power supply is 0-100V; the voltage is constant and the solution temperature is kept be at 20-70 DEG C in the purification process; and the recovery rate of the organic amine electroplating additive after being purified is greater than 80%. The method for purifying the organic amine electroplating additive, disclosed by the invention, is simple in process and easy to control, and the purification degree can achieve the fine electronic grade standard.

The invention relates to a continuous preparation method of electronic-grade methyl silicone oil, which comprises the following steps: pretreating raw materials: carrying out metal complexing agent rectification purification or molecular sieve adsorption treatment and metal complexing agent rectification purification on the raw materials and auxiliary materials in series for use; premixing the rawmaterials: inputting the pretreated raw materials into a screw mixer according to a certain mass ratio, and performing heat preservation and mixing; polymerization: inputting the premixed material into a first-stage static fluidized bed for prepolymerization, and then inputting into a second-stage static fluidized bed for equilibrium polymerization to obtain a semi-finished product; and carryingout low-boiling-point substance removal: inputting the semi-finished product into a film evaporator, primarily removing low-boiling-point substances through first-stage purification, and then inputting the semi-finished product into a short-path low-molecular distiller for second-stage purification to obtain a finished product. The process is a continuous production process, polymerization is stable, the conversion rate is high, the finished product indexes are as follows: the molecular weight distribution coefficient is small, the low-boiling-point substance content is less than 0.20%, the silicon hydroxyl content is low, the Na, K and heavy metal ion content is less than 10ppb, and the application requirements of industries such as electronics, microelectronics and the like can be met.

The invention relates to the field of solvent recycling, in particular to a method for recycling N-methylformamide and diethylene glycol monomethyl ether in paint remover waste liquid. The method adopts an extraction dividing-wall rectifying method to recycle N-methylformamide and diethylene glycol monomethyl ether in paint remover waste liquid; the paint remover waste liquid is rectified and separated through a main tower and an auxiliary tower of an extraction dividing-wall rectifying tower, and N-methylformamide crude product and diethylene glycol monomethyl ether crude product are obtainedrespectively; the N-methylformamide crude product passes through a N-methylformamide refining tower and a metal removing tower to obtain N-methylformamide, and the diethylene glycol monomethyl ethercrude product passes through a diethylene glycol monomethyl ether refining tower and the metal removing tower to obtain diethylene glycol monomethyl ether. The method can be adopted to conduct continuous production; the separation of the N-methylformamide and the diethylene glycol monomethyl ether is achieved; the method has the advantages that the purity of separated products is high; the technological procedure is simple; energy consumption and equipment investment in the separation process can be effectively lowered at the same time.