光氯化反应脱除三氯氢硅中的甲基二氯硅烷

以三氯氢硅和氯气为原料,采用连续流微通道反应器,利用光氯化反应选择性脱除三氯氢硅中的甲基二氯硅烷,考察了各因素对甲基二氯硅烷去除率的影响。结果表明,光氯化反应的最优条件为:n(Cl_2)∶n(CH_4Cl_2Si)=5∶1,反应温度50℃,紫外光波长为365 nm,光强为15 W,反应时间为20 s。在最优条件下,产品中甲基二氯硅烷含量小于5×10~(–8) g/g,去除率达到99.67%;反应产物中出现少量四氯化硅,是聚氯硅烷和三氯氢硅发生氯化反应生成的。以最优条件制备的三氯氢硅为原料,使用评价炉制备的多晶硅中碳原子浓度小于3×10~(15) atoms/cm~3,达到电子一级品指标。     

分离三氯氢硅中甲基二氯硅烷的研究进展

三氯氢硅中的甲基二氯硅烷含量会严重影响多晶硅的品质,控制三氯氢硅中的甲基二氯硅烷含量对多晶硅的品质具有重要意义。重点介绍了三氯氢硅中甲基二氯硅烷的深度去除方法,包括常规精馏法、吸附法、反应精馏法和萃取精馏法。对比分析了上述方法的优缺点,其中吸附法、反应精馏法是分离甲基二氯硅烷行之有效的方法,萃取精馏法也是分离甲基二氯硅烷的重要研究方向,并对这些工艺的发展方向进行了展望。     

非线性光学晶体3BiCl3·7SC(NH2)2的合成及其转化过程

针对金属有机配合物非线性光学晶体3BiCl3?7SC(NH2)2 (DCBPB)合成过程中伴生BiCl3?3SC(NH2)2 (β-BTC)的问题，以硫脲与氯化铋为原料，在甲酸?水体系中研究了溶剂配比、反应温度、反应物配比等因素对DCBPB纯度的影响，对反应条件进行了优化，并基于XRD特征峰面积标准曲线法研究了β-BTC与DCBPB之间的转化过程。结果表明，甲酸抑制氯化铋水解且选择性生成DCBPB，氯化铋与硫脲摩尔配比大于1:3时可选择性生成DCBPB。合成过程先生成β-BTC，再由β-BTC转化为DCBPB，甲酸?水体系中氯化铋水解发生在β-BTC生成过程中，且不可避免，导致基于氯化铋直接合成只能获得最高含量为89.91wt%的DCBPB晶体。β-BTC向DCBPB转化率极高且无水解，可获得DCBPB含量大于98wt%的晶体。     

四氯化硅热氢化制备三氯氢硅

以四氯化硅和氢气为原料,利用固定床反应器高温热氢化制备三氯氢硅,研究了反应温度、反应空速、反应压力及原料物质的量的比对三氯氢硅收率的影响。结果表明,在一定条件下,升高温度,增大压力,降低空速和增加氢气(H2)与四氯化硅(Si Cl4)物质的量的比,有利于增加三氯氢硅收率;但当反应温度、反应压力、氢气与四氯化硅配比增大到某一值或反应空速降低到某一值时,三氯氢硅收率增加不明显甚至有所降低。实验结果表明,四氯化硅高温热氢化制备三氯氢硅较佳工艺条件是反应温度小于1 050℃,反应压力高于0.6 MPa(表压),反应空速不大于1 000 h-1,原料氢气和四氯化硅物质的量的比为4~6。在最佳反应条件下,三氯氢硅收率达到19.81%。     

双环戊二烯二氯化铂催化剂硅氢加成选择性的研究

在双环戊二烯二氯化铂催化剂的作用下，在相似的反应条件下，分别通过１－己烯和苯乙烯与甲基二氯硅烷的硅氢加成反应合成了相应的二取代基二氯硅烷单体。根据产物的￣１Ｈ－ＮＭＲ谱，观察到此种催化剂对１－己烯和苯乙烯与甲基二氯硅烷的硅氢加成的选择性存在很大的差异，即１－己烯与甲基二氯硅烷的硅氢加成，只生成β产物；而苯乙烯与甲基二氯硅烷的硅氢加成，则生成４４％的α产物和５６％的β产物。结合文献进行了分析。     

促进剂存在下三氯化铝歧化甲基氯硅烷反应机理探讨

探讨了一甲基三氯硅烷和三甲基一氯硅烷歧化反应机理。实验结果表明,在促进剂一甲基二氯硅烷存在下,以AlCl_3催化的一甲基三氯硅烷与三甲基一氯硅烷的歧化反应实现了一甲基三氯硅烷和三甲基一氯硅烷的有效利用,制得了甲基氯硅烷混合物,反应过程主要为亲核取代反应;一甲基二氯硅烷的主要作用是与AlCl_3结合促进配位化合物[AlCl_4]~-的形成;反应前后一甲基二氯硅烷的含量变化较小。     

氯硅烷中甲基二氯硅烷的转化反应工艺

为了除去多晶硅原料中主要含碳杂质甲基二氯硅烷,通过催化反应将其转化为高沸点物质甲基三氯硅烷。采用浸渍法制备了Pd/Al2O3催化剂,将其用于催化甲基二氯硅烷的转化。采用XRF、XRD、BET、XPS、H2-脉冲化学吸附技术对催化剂物化性质进行表征。以四氯化碳为氯源,利用固定床反应器,对比了Pd/Al2O3催化剂、树脂A催化剂及Al Cl3/Al2O3催化剂的催化效果。重点考察了反应温度、反应物物质的量比、反应液时空速及催化剂稳定性对甲基二氯硅烷转化率的影响,得到了最佳工艺条件。相比于树脂A催化剂和Al Cl3/Al2O3催化剂,Pd/Al2O3催化剂具有更好的催化效果;在反应温度为140℃、n(甲基二氯硅烷)∶n(四氯化碳)=3∶1、反应液时空速为5.0 h–1时,甲基二氯硅烷转化率最高可以达到69.76%。     

氯硅烷中甲基二氯硅烷的转化反应工艺 急

为了除去多晶硅原料中主要含碳杂质甲基二氯硅烷，通过催化反应将其转化为高沸点物质甲基三氯硅烷。采用浸渍法制备了Pd/Al2O3催化剂，采用X射线荧光光谱（XRF）、X射线粉末衍射（XRD）、N2吸附脱附（BET）、光电子能谱仪（XPS）、H2-脉冲化学吸附等分析手段对催化剂物化性质进行表征。在氯源物质为四氯化碳条件下，利用固定床反应器，对比了制备的Pd/Al2O3催化剂与树脂A催化剂和AlCl3/ Al2O3催化剂的催化效果,考察了Pd/Al2O3催化条件下，反应温度、反应物配比、反应空速及催化剂稳定性对甲基二氯硅烷转化率的影响，得到了最佳工艺条件。Pd/Al2O3催化剂相比于树脂A催化剂和AlCl3/ Al2O3催化剂，Pd/Al2O3催化剂具有更好的催化效果；在反应温度为140℃、n(甲基二氯硅烷):n(四氯化碳)=3:1、反应液时空速为5.0h-1时，甲基二氯硅烷转化率最高可以达到69.76%。     

三碘化铑的新合成方法

三氯化铑与氢碘酸直接合成碘化铑,在最佳反应条件下,合成的收率达到98.5%,产品晶形均一,氯离子含量小于50 mg/kg。     

γ-氯丙基甲基二甲氧基硅烷合成工艺的研究

γ-氯丙基甲基二甲氧基硅烷通常先由甲基二氯硅烷与氯丙烯通过硅氢加成生成γ-氯丙基甲基二氯硅烷，再经醇解得到。在合成γ-氯丙基甲基二氯硅烷的硅氢加成反应中，选用三乙胺作助催化剂与氯铂酸复合形成催化剂体系，并通过正交实验法优选出该反应的最佳工艺条件，其产率达到85%，而且反应时间大大缩短。使用正交实验法对合成最终目标产物的醇解反应进行改进以选出最佳工艺条件，并且在反应过程中通过不断通入氮气来排尽HCl气体。反应过程中无需另外加入溶剂，使分离与提纯大大简化，从而达到节约成本、降低能耗的目的，是工业上切实可行的优选合成工艺。     

Hydrosilylation of long chain unsaturated fatty acid esters

The addition of a series of silicon hydrides: trichlorosilane, methyldichlorosilane, dimethylchlorosilane, phenyl dichlorosilane, and methyl phenyl chlorosilane to esters of long chain unsaturated fatty acids, such as oleic, linoleic acids, and 10-undecenoic acid, was studied with respect to catalysts, temperature, and solvents. Higher yields were obtained on carrying out the hydrosilylation reactions in the presence of chloroplatinic acid or Pt on C catalysts in bulk without solvent, as compared with peroxide catalysts. The addition reaction with methyl 10-undecenoate, which has a terminal double bond, gave a higher yield than that with methyl oleate. NMR data of the products from methyl 10-undecenoate and methyl oleate, as well as their reduction products with lithium aluminum hydride, have shown that, with the former ester, the silyl moiety added exclusively to the terminal carbon atom, while, with the latter, no migration of the silyl moiety to the terminal carbon atom was observed.     

提高γ-氯丙基三氯硅烷含量的技术探讨

针对以铂化合物为主要催化剂、用置氯硅烷和氯丙烯生产,γ-氯丙基三氯硅烷出现的成品含量低、杂质含量高、原料（以三氯氢硅计）转化率低、产品效益差等问题,结合反应机理,提出了加入助催化剂、活化剂等助剂、在半成品中通一定量亚硫酰氯使副产物转化为目标成品、优化蒸馏工艺等方法,剥‘提高成品含量进行了较为深入的探讨。提出的解决方案已实现工业化。     

Analysis of the Pyrolysis Products of Dimethyldichlorosilane in the Chemical Vapor Deposition of Silicon Carbide in Argon

A study of the products and reactions occurring during the chemical vapor deposition of silicon carbide from dimethyl-dichlorosilane in argon is presented. Reaction conditions were as follows: 700° to 1100°C, a contact time of ∽1 min, and a pressure of 1 atm (∽0.1 MPa). At these conditions, the gases that formed were mainly methane, hydrogen, silicon tetrachloride, trichlorosilane, and methyltrichlorosilane. Hydrogen chloride might also be present, but was not determined. The silicon carbide solid that formed showed the presence of hydrogen and chlorine as impurities, which might degrade the silicon carbide properties. These impurities were eliminated slowly, even at 1100°C, forming hydrogen, trichlorosilane, and silicon tetrachloride.     

三氯氢硅技改措施及效果

分析了三氯氢硅生产中存在的问题,提出技改措施,改造后氯化氢含水体积分数在1×10-4左右,产品中含硼质量分数低于4×10-8,硅粉单耗降低30 kg/t.     

四氯化硅转化技术的现状与发展趋势

介绍以四氯化硅为原料生产的几种化学产品（气相法白炭黑、硅酸乙酯、多晶硅、光纤材料、三氯氢硅）的生产技术的现状和发展趋势,并分析这些产品的市场容量和对消耗四氯化硅所起的作用。国内多晶硅的大规模生产即将兴起,解决其副产物四氯化硅的最有效的方法是转化为三氯氢硅。着重介绍国内外四氯化硅氢化技术,及笔者正在开发的等离子体四氯化硅还原新工艺。     

Comparison of the Pyrolysis Products of Dichlorodimethylsilane in the Chemical Vapor Deposition of Silicon Carbide on Silica in Hydrogen or Argon

A chemical analysis of the pyrolysis gases and solids formed during the deposition of silicon carbide from the decomposition of dichlorodimethylsilane in argon and hydrogen is reported. Depositions were performed at 1 atm pressure, temperatures from 700° to 1100°C, and a mean residence time of approximately 1 min. The chemical analysis shows that, under reactor conditions, the gases formed were mainly methane, hydrogen, silicon tetrachloride, trichloro-silane, and trichloromethylsilane. The presence of hydrogen chloride was not examined. The use of hydrogen, as a carrier gas, decreased the trichloromethylsilane and solid aerosol (smoke) in the reaction products, compared to that present in the argon system, and increased methane, trichlorosilane, and silicon production. Primarily, silicon and silicon carbide were deposited when hydrogen was used as the carrier gas. When argon was used, a complex mixture of silicon carbide and organosilicon compounds was formed. It is hypothesized that, when hydrogen was used as the carrier gas, silicon carbide formed from chlorosilanes and methane, which were products from the decomposition of dichlorodimethylsilane. These products subsequently reacted to form silicon, which then reacted with methane to form silicon carbide. In argon, however, it is hypothesized that silicon carbide can be formed in two ways: (1) from the pyrolysis of solid organosilicon compounds which are products from the pyrolysis of dichlorodimethylsilane in argon and (2) as the reduction of dichlorodimethylsilane to chlorosilanes and methane, caused by the hydrogen produced from the pyrolysis of dichlorodimethylsilane in argon.     

笼形氢基倍半硅氧烷的合成与表征

在控制水含量和体系温度的前提下,在两相溶剂中,三氯硅烷在FeC l3催化下发生水解缩合,反应生成笼形八氢基倍半硅氧烷和十氢基倍半硅氧烷,然后分离、中和干燥、纯化,重结晶后制得八氢基倍半硅氧烷,产率大约19%。利用傅里叶红外光谱1、H核磁共振光谱2、9S i核磁共振光谱、X射线衍射和热分析等手段,对它的结构和性质进行了表征。     

TPD study for direct synthesis of methylchlorosilanes

Temperature programmed desorption (TPD) was performed to obtain information about the role of silicon, catalyst (copper), and promoters (zinc and tin), and to characterize the active sites for the formation of silanes. Use of infrared spectroscopy allowed rapid analysis of the gas-phase product composition. During TPD where methyl chloride was used as an adsorbate, methyl chloride (MeCl), hydrogen chloride (HC1), methane (CH₄) and silanes were produced from contact masses. Although dimethyldichlorosilane (DMDC), methyltrichlorosilane (MTCS), methyltrichlorosilane (MTCS), trimethylchlorosilane (TMCS) and dimethylchlorosilane (DMCS) were produced during the direct reaction, tetrachlorosilane (QCS), trichlorosilane (TCS), methyltrichlorosilane (MTCS), and methyldichlorosilane (MDCS) were the major silanes observed during the TPD. Zinc promotion to silicon-copper contact mass (CuSi mass) increased the production of TCS, while tin promotion decreased the production of silanes having H atom, and increased the production of MTCS. Copromotion of 0.5 wt% zinc and 0.2 wt% tin increased the MTCS production further; however, the copromotion of zinc (0.5 wt%) and tin containing a small amount of tin (0.01 wt%) produced QCS as a major silane product. The silicon sites having two or three surface species such as CH₃, Cl and H were proposed as the active sites responsible for the formation of silanes, and the silicon sites of = SiCl₂ and =Si(CH₃)Cl were the most abundant under the steady state condition.     

光氯化法合成ClCH_2SiCl_3的研究

氯甲基三氯硅烷 (ClCH2 SiCl3)是以一甲基三氯硅烷 (CH3SiCl3)为原料 ,在光的催化下经氯化而成。本方法采用Cl2 为氯化剂 ,在可见光 (白炽灯 )催化下 ,气相法合成ClCH2 SiCl3。研究了光源特性 (如光源强度 ,波长 )及反应器材质对光氯化反应的影响 ,从而确定了氯化反应所需要的能量及反应参数 ,并且从理论上对反应机理、特性进行了论述     

四氯化硅催化氢化制备三氯氢硅

针对四氯化硅氢化反应,采用等体积浸渍法制备了以HZSM-5为载体,金属氯化物为活性组分的负载型四氯化硅氢化反应催化剂,考察了催化剂的催化性能,并进行了相应表征。结果表明,碱土金属氯化物对四氯化硅氢化过程有良好的催化效果,在BaCl2负载质量分数为1%和反应温度850℃条件下,反应最高转化率为20.20%,选择性83.01%。