1497 results about "Silicon tetrachloride" patented technology

According to one exemplary embodiment, a method for forming a field-effect transistor on a substrate comprises a step of forming a buffer layer on the substrate, where the buffer layer comprises ALD silicon dioxide. The buffer layer can be formed by utilizing a silicon tetrachloride precursor in an atomic layer deposition process, for example. The buffer layer comprises substantially no pin-hole defects and may have a thickness, for example, that is less than approximately 5.0 Angstroms. The method further comprises forming a high-k dielectric layer over the buffer layer. The high-k dielectric layer may be, for example, hafnium oxide, zirconium oxide, or aluminum oxide. According to this exemplary embodiment, the method further comprises forming a gate electrode layer over the high-k dielectric layer. The gate electrode layer may be polycrystalline silicon, for example.

The invention discloses a porous silicon/carbon composite material and a preparation method thereof, and belongs to the fields of electrochemistry and new energy materials. The method comprises the following steps of: preparing porous silicon dioxide by using ethyl orthosilicate, silicon tetrachloride, methyl silicone oil and sodium silicide as raw materials, reducing the porous silicon dioxide into porous silicon, coating the porous silicon by adopting an organic carbon source, and performing thermal treatment under an inert atmosphere to prepare the porous silicon/carbon composite material. The material can be directly used as the lithium ion battery cathode material, the first discharge specific capacity of the material can reach 1,245mAh/g, the specific capacity can also reach 1,230mAh/g after 30 cycles, and the material has excellent charge/discharge performance.

The invention discloses a method for preparing white carbon black by utilizing silicon tetrachloride. The method comprises the following steps: mixing deionized water and low molecular fatty alcohol at the molar ratio of 1:4-4:4, and adding a proper amount of surfactant; slowly adding a certain amount of the silicon tetrachloride at the room temperature; and obtaining the white carbon black through the steps of preparing reaction solution, curing the reaction solution, sedimentation and abstersion, pulpifying and spray drying, wherein the concentration of the silicon tetrachloride is controlled to be 0.2-1.0 mol.1-1, and modifiers such as 0.01-0.1mol.1-1 of Hexamethyl disilazane and the like can be added in the preparation process of the hydrophobic white carbon black. The grain diameter of the prepared white carbon black is 50-350nm and the specific surface area is 100-300m<2>.g-1; and the method has high economic value and the prepared white carbon black has good hydrophobic effect.

The invention relates to a method for preparing a molecular sieve, which comprises the following steps: the molecular sieve is introduced in a gas phase ultra-stable reactor, the gas phase ultra-stable reactor is capable of moving the molecular sieve from the molecular sieve inlet of the gas phase ultra-stable reactor to the molecular sieve outlet of the gas phase ultra-stable reactor under the condition that carrying gas is not used for conveying, and the molecular sieve and gas-phase silicon tetrachloride are contacted for reacting in the gas phase ultra-stable reactor. The conveying of the molecular sieve does not require inertia carrying gas, the technology flow is simplified, carrying gas amount is saved, and the consumption of silicon tetrachloride can be greatly reduced.

The invention relates to an aryl silicate ester flame retardant plasticizer and a preparation method thereof. The structure of the compound is expressed with a general formula shown in the specification, wherein R is phenyl, tolyl and benzyl, R' is hydrogen and methyl, and R'' is hydrogen and methyl or chloromethyl. The preparation method comprises the following steps: using nitrogen to protect, and reacting silicon tetrachloride with a hydroxyl compound with an aryl having the same molar ratio as that of the silicon tetrachloride to release hydrogen chloride, and then with alkylene oxide with a certain molar ratio to obtain a target product. The target product also can be obtained through changing the feeding sequence. The compound has the advantages of stable physical and chemical properties, high flame retardant performance, good plasticity, simple process and easiness of large-scale production.

The invention relates to a preparation method of a silicon/graphene laminar composite material for lithium ion battery cathode. The composite material adopts a laminar sandwich structure, silicon nano-particles are dispersed on each lamina of the grapheme, the laminas of the grapheme are separated from one another by the silicon nano-particles and the edges of the laminas are in lapped joint so as to constitute a laminar conductive network structure. The preparation method thereof comprises the steps of: formulating anhydrous silicon tetrachloride, surface active agent, sodium naphthalene and graphite oxide to tetrahydrofuran solution, adding the tetrahydrofuran solution into a reactor for reaction in vacuum at the temperature ranging from 380 to 400 DEG C, filtering the reactant to result in the product, and then washing, drying and heating the product to obtain the silicon/grapheme composite material. The preparation method of the invention has the advantages of simple preparation process and great easiness for industrial production; and the silicon/graphene laminar composite material prepared according to the method includes excellent conductivity, power performance, electrochemical activity and cycle stability, and is particularly suitable for manufacturing lithium ion battery cathode.

Process for production of acid and high temperature resistant cement composites, where the matrix is alkali activated F fly ash alone, F Fly ash combined with ground slag or ground slag alone. F-fly ash produces lower quality alkali activated cement systems. On the other hand the lack of calcium oxide results in very high resistance to medium and highly concentrated inorganic or organic acids. The high strength and low permeability of pure F-fly ash cement systems is achieved by using in the composition un-densified silica fume, the amorphous silicone dioxide obtained as by products in production of ferro-silicones. Precipitated nano-particle silica made from soluble silicates and nano-particle silica fume produced by burning silicon tetra chloride in the hydrogen stream.

The silicon tetrachloride hydrogenating process of producing trichloro-hydrosilicon includes: mixing powdered nickel catalyst and silicon powder in the mass ratio of 1-10 and activating the mixture in hydrogen atmosphere and at the temperature of continuously change from 20 deg.C to 420 deg.c; and making mixed gas of hydrogen and SiCl4 in the molar ratio of 1-10 pass through the activated catalyst and silicon powder layer for hydrogenating SiCl4 continuously at 400-500 deg.c temperature and 1.2-1.5 MPa pressure. The equipment, system and operation of the present invention has high once SiCl4 converting rate and low power consumption and may be used in large-scale production.

The invention relates to an improved method and equipment for the preparation of trichlorosilane and polysilicon. The trichlorosilane is prepared by a chlorine hydrogenation method during the preparation process of polysilicon. The process is as follows: a) the metallurgical silicon is put into a reactor after being heated to 300-500DGE C in a powder baker; b) the silicon tetrachloride is vaporized and heated through an external heating device, which generates the silicon tetrachloride gas at the temperature of 160-600DGE C; c) the hydrogen chloride gas is preheated to 150-300DGE C through the external heating device; d) the hydrogen gas is preheated to 300-600DGE C through a heater; and e) the gases of step b), c) and d) are added into the reactor; wherein, the molar ratio between the hydrogen gas and the silicon tetrachloride is 1-5:1, the molar ratio between the hydrogen chloride gas and the silicon tetrachloride is 1: 1-20; and the temperature in the reactor is maintained at 400-600DGE C and the pressure in the reactor is kept at 1.0-3.0MPa. The method of the invention can effectively prepare the polysilicon at a low cost, which suits for semiconductor industry and solar battery.

The invention relates to a method and an apparatus for preparing trichlorosilane through reaction rectification by using proportionate reaction. The method comprises the following steps of: reacting dichlorosilane with silicon tetrachloride in the upper middle part of a reaction rectification tower, obtaining incompletely reacted dichlorosilane at the top of the reaction rectification tower; reflowing at the top of the tower and in the middle of the tower, obtaining a mixture of dichlorosilane, trichlorosilane and silicon tetrachloride at the bottom of the tower, entering a light-end removal tower to remove a light component, obtaining the dichlorosilane at the top of the light-end removal tower; reflowing to the reaction rectification tower for recycling, obtaining a mixture of trichlorosilane and silicon tetrachloride at the bottom of the tower, entering a heavy-end removal tower to separate the trichlorosilane from the silicon tetrachloride, wherein the trichlorosilane at the top of the heavy-end removal tower is a product; and taking out the silicon tetrachloride at the side line of the lower part of the tower, entering the reaction rectification tower for recycling, and obtaining excessive silicon tetrachloride at the bottom of the tower. In the invention, by utilizing the proportionate reaction, the utilization ratio of the raw materials is enhanced; the problem of dichlorosilane and silicon tetrachloride enrichment is solved; and the final conversion ratio of the dichlorosilane is ensured to reach 100 percent theoretically.

A process for producing hexachlorodisilane comprising, condensing an exhaust gas discharged from a reactor for producing polycrystalline silicon from a chlorosilane and hydrogen to separate the hydrogen, distilling the resultant condensate to separate the unreacted chlorosilane and by-product silicon tetrachloride, and then further distilling to recover hexachlorodisilane, wherein tetrachlorodisilane can be recovered together with the hexachlorodisilane, and the hexachlorodisilane and tetrachlorodisilane recovered have a far higher purity than the conventional ones produced from metallic silicon.

The invention relates to a hydrogen recovery method in the exhaust generated by producing polysilicon. The exhaust mainly comprises hydrogen, chlorine hydride, dichlorosilane, trichlorosilane and tetrachlorosilane. The method comprises the following steps: pressurizing and cooling the exhaust in order to turn trichlorosilane and tetrachlorosilane to liquid state while hydrogen, chlorine hydride and dichlorosilane still being gas state, so that the gas hydrogen, chlorine hydride and dichlorosilane can be separated from the liquid trichlorosilane and tetrachlorosilane by gas liquid separation; dissolving the gas chlorine hydride and dichlorosilane into the liquid tetrachlorosilane by passing gas hydrogen, chlorine hydride and dichlorosilane through the liquid tetrachlorosilane, so that separating the hydrogen from chlorine hydride and dichlorosilane. The invention recovers the hydrogen in the exhaust by dry treatment and the hydrogen can be reused in the polysilicon production, which makes good use of the material, reduces pollutants, settles the problem of environmental pollution, improves the product quality and reduces the cost.

The invention discloses a method for the synthesis of a polysilicon raw material trichlorosilane. The method comprises the following steps: A) silica powder is conveyed to a trichlorosilane synthesis furnace by dried hydrogen chloride gas; B) hydrogen chloride for reaction is input into the synthesis furnace from the bottom of the trichlorosilane synthesis furnace proportionally and proper amount of hydrogen and silicon tetrachloride are added in the synthesis furnace at the same time; C) silica powder and hydrogen chloride react at the temperature of 280-310 DEG C to generate mixing gas containing trichlorosilane and silicon tetrachloride; D) the mixing gas of dust and high chlorosilane is removed, after water cooling and pressuring by a diaphragm compressor, trichlorosilane and silicon tetrachloride are condensed into liquid by a refrigerant with -40 DEG C, wherein, noncondensable gas containing H2 and HCI is separated. The method of the invention can improve the yield of trichlorosilane from 82 percent to more than 88 percent.

This invention relates to a method for separating and purifying mixing exhaust gas of chlorine and hydrochloride, comprising: absorb the chlorine in the mixing exhaust gas using solvent A to separate from gas phase hydrochloride, the chlorine can be obtained after solvent A desorption, the hydrochloride can be obtained by removing solvent A in the gas phage hydrochloride using solvent B, wherein: solvent A is one of benzene, silicon tetrachloride, nonyl hydride, sulfur monochloride, carbon tetrachloride and chlorosulfonic acid, and solvent B is one of cyclopentadiene and hexachlorobutadiene. By washing with concentrated hydrochloric acid to remove trace amount of organic compounds, and chemical washing to remove heavy metal elements, the hydrochloride is absorbed by water to make hydrochloric acid. This invention is characterized of efficient separation of chlorine and hydrochloride, high efficiency of separation, low cost, high-usage of resources, high purity of chlorine up to 99%, recycling use, and the purity of hydrochloride meets the requirement of producing industrial hydrochloride and hydrochloride regent .

The invention relates to a tris(dichloropropyl) tribromophenoxy chloropropyl silicate compound which is a silicon-halogen synergistic fire retardant, and a preparation method of the compound. The compound has a structure shown in a formula described in the specification; and in the formula, OC3H5Cl2 is OCH2CHClCH2Cl or OCH (CH2Cl) 2. The preparation method of the compound comprises the following steps: reacting tribromophenyl glycidyl ether and silicon tetrachloride according to the same molar ratio in an organic solvent for 4-6h at 60-80 DEG C; then dropwise adding dichloropropanol according to a certain molar ratio, reacting for 4-8h at 50-100 DEG C; and finally purifying to obtain faint yellow liquid which is the tris(dichloropropyl) tribromophenoxy chloropropyl silicate. The compound is applicable to fire retardants for polyvinyl chloride, polyurethane, epoxy resin, unsaturated resin and other materials; and the production process is simple, low in equipment investment and cost, and suitable for industrial production.

Siloxane oligomers of the general formula I or II wherein at least one functionalized alkyl group is present per oligomer molecule. The siloxane oligomers are produced by oligomerization of halogenalkyltrihalogensilanes, and co-optionally co-oligomerized with (C1-C18)-alkyl-, phenyl-, aryl- or aralkyl-trihalogensilanes and/or silicon tetrachloride, in the presence of alcohol and water, following which the halogenalkyl function is optionally modified in a further step. The siloxane oligomers can be used as coupling agents in rubber mixtures or as building preservation agents.

The invention provides a production method of 1,1,1,3,3-pentachlorobutane (HCC-360jfa), in which carbon tetrachloride and 2-chloropropene are taken as raw materials for continuous reaction in a tubular reactor to synthesize the 1,1,1,3,3-pentachlorobutane. In the method, the carbon tetrachloride and 2-chloropropene are firstly mixed and preheated to reaction temperature; the carbon tetrachloride and 2-chloropropene enter the tubular reactor with a catalyst for telomerization; a product undergoes flash evaporation to remove the un-reacted tetrachloride and 2-chloropropene and then is further distilled to obtain the HCC-360jfa product; the un-reacted tetrachloride and 2-chloropropene are recycled; and the catalyst undergoes activating treatment for recycle. The catalyst used by the invention is liquid, no solid exists in the reaction product, and the tubular reactor is used for reaction, so that the invention is convenient for operation and easy for continuous production.

A process for preparing trichlorosilane by reacting silicon with hydrogen chloride, or silicon tetrachloride with hydrogen in the presence of silicon, and catalysts where the silicon and catalysts are laminated together and reduced in particle size prior to reaction.

The present invention includes a process and means for using two isolated by-products from the reaction of at least one of metallurgical silicon and silicon tetrachloride with at least one of anhydrous hydrogen chloride and hydrogen to produce trichlorosilane. The two isolated by-products are dichlorosilane and silicon tetrachloride. The present process reduces chlorosilane waste and improves efficiency of overall process for production of trichlorosilane for use in chemical vapor deposition of polysilicon for electronic and solar applications. The present invention further includes a chemical reactor for the reacting dichlorosilane with silicon tetrachloride to produce additional trichlorosilane.

The invention relates to a nitrogen, silicon and chlorine thee-element synergic flame retardant tri{2-chloro-3-[tri(chloroethoxy)silicon acyloxy]propyl}isocyanurate compound and a preparation method thereof. The structure of the compound is shown as a formula in the specification. The preparation method comprises the following steps: dripping organic solvent solution of triglycidyl Isocyanurate into silicon tetrachloride, and reacting for 4 to 6 hours at a temperature of between 50 and 70 DEG C; and cooling to 30 DEG C, introducing ethylene oxide under the liquid surface, reacting for 2 to 3 hours at a temperature of between 45 and 55 DEG C, and purifying to obtain the tri{2-chlor-3-[tri(chloroethoxy)silicon acyloxy]propyl}isocyanurate. The compound has good flame retardant plasticization, and is suitable for flame retardant plasticizer such as polyvinyl chloride, polyurethane, epoxy resin, unsaturated resin and the like; and the method has simple production process and low cost, and is easy for industrial production.

The invention discloses a production method of silane. The production method comprises the following steps of: heating trichlorosilane to 70-90 DEG C by using a preheater; feeding heated trichlorosilane into a first reaction region of a reaction rectifying tower, and performing a first step catalytic disproportionation reaction of trichlorosilane in the first reaction region to generate dichlorosilane and silicon tetrachloride; feeding silicon tetrachloride generated in the first reaction region into the stripping section of the reaction rectifying tower, separating, purifying and discharging from a tower kettle; raising dichlorosilane generated in the first reaction region to a second reaction region of the reaction rectifying tower, and performing a second step catalytic disproportionation reaction to generate trichlorosilane and silane; refluxing the trichlorosilane generated in the second reaction region into the first reaction region, mixing with trichlorosilane heated by using the preheater, and continually performing the first step catalytic disproportionation reaction; and raising silane generated in the second reaction region into the rectifying section of the reaction rectifying tower, separating, purifying and discharging from the tower top of the reaction rectifying tower to obtain silane.