KIMURA  Hajime

Muroran-IT Academic Resource Archive

On the Direct Synthesis of PhenylchlorosilanesWith Several Catalysts and FractionalDistillation Analysis著者 KIMURA  Hajimejournal orpublication titleMemoirs of the Muroran College of Technologyvolume 1number 2page range 69-77year 1951-06-05URL http://hdl.handle.net/10258/2990On the Direct Synthesis of Phenylchlorosilanes With Several Catalysts and Fractional Distillation Analysis Hajime Kimura Introduction On the synthesis of organohalosilanes which are the intermediates of silicone polymer various methods of synthesis have been devised， they may be classified by as either methods， substitution method (iιthe methodl of KIPPUfG-BYGDEN九羽TUHTZ-FITTIG2" and GRlGNARD~)) or direct method (i.e. the method of E. G. ROCHOW4J， and TAYLOR， W ALDEN5))・ Thedirect method， however， has suddenly risen in importance in the modern silicon industry， since this method have been adopted by the Dow-Corning Cかoperation.In the direct method， the mixture of crystalline or elementary silicon and suitable catalyst is caused to react directly with a hydro-carbon hallide to produce of organosilicon halides. This is a general reaction for both alkyl and aryl hydrocarbon halides in either the 1iquid or the vapor phase. However， itis most convenient to use hydrocarbon chlorides as stating material and to carry out the reaction in the gas phase at a temperature of 200 -450"C， depending upon the reactivity of the particular chloride. It is apparent that at the .higher temperatures which may be required for reaction of the more inert chlorides the organic compounds may suffer considerable pyrolysis， with consequent deposition of carbon in the reactive zone. Such decomposition can be avoided in large part by the use of a metallic or a metal oxide catalyst which will reduce the temperature required for e詑ectivereaction. Powdered copper is one of such catalysts and has been used satisfactorily in a reaction of methylchloride with elementary si1icon to prepare methylchlorosi1anes. The use of the former copper catalyst enables one to reduce the reaction temperature by about 200-2500C， and to obtain satisfactory conversion of the methyl chloride without large loss by pyrolysis. 1)_ By臼DEN:Ber. 44， 2640 (1910). KTPI'lNG & LIOY叩: J.C.S. 79， 449 (190l). 2) S('ITUMB， ACK'ERMANN and SAlo'FlCR: J.A.C.S. 60， 2486 (1938). 3) SCIIU~1B and SM明 m:J.A.C.S. 61， 363 (1939). 4) E. G. R(XeHOW and GTLLTAM: JAC.S. 68， 798 (1941). GrrJ，lAM: J.A.C.S. 63， 1194 (1941). 5) A. G. TAYLOR and WALDEN: J.A.C.S. 66， 842 (1944). 70 H. Kimurα In this case， the yield of methylchlorosilanes was nearly 100 per cent. On the other hand， itis reported that， .in the reaction of chlorobenzene with silicon to form phenylchlorosilanes， finely divlded silver is more effeetive than copper as a catalyst， although the .reduction temperature is ， 2500C， and the yield is about 10%一By the use of reduction with hydrogen gas at 200"C， Dr. T. YAMADAのhas recently obtained excellent results to prepare alkylchlorosilanes， showing about 120% yield by weight， The author carried out a synthetic experiment of phenylchlorosilanes by the reaction of chlorobenzen with metallic silicon in the presence of copper and siIver catalysts reduced on YAl¥fADA'S principle. The author will make a report in this paper with regard to a prepa圃ration of catalysts， a fractional distillation analysis of the products， and an infiuence of the catalysts on the products or yield. Experimental a) SYNTUETIC ApPARATUS AND GENERAL PROCEDURE 苫Fig. 1. Apparatus of Synthesis. The apparatus is shown in Fig. 1. The reactant consists of me-tallic silicon powder catalyst， and silica as a carrier in which the lattθr is 10 per cent of metallic silicon respectively. It packed into a pyrex reaction tube H about 30-40 grams， passing hydro-gen. gas through the packing at 2000C (in copper catalyst) or 2500C (in silver catalyst)， this tube being heated wIth electric furnace， then the packing was dried expelling water， and reducing stiH more， the dehydration was stopped within about 20 hours. The higher reduction temperature does not show a good activity for the pyrolysis. After reduction， stopping the宜owof hydrogen， raising the reduction temperature， and dropping mercury from burette E， then the reactton was carried on by forcing chlorobenzene in F to the packing.、Some of this product condensed in the adaptor J through the water-6) 山間・安永・金指:電気試験所支報， 13巻， 9波， 31頁.一、On the Direct Synthesis of Phenylchlorosu，αnes With Several Catalysts 71 cooled condenser 1 and another the component of low boiling point was exhausted through ice-cooled trap K and phosphor pentaoxyde drying tube L. The above treatment was done with precautions noticing the bad e古ectof moisture upon this reaction. The reaction was continuous but the following velocity was unable to be constant which is in 5-10 gjhr. It required about 24 hours and the product could be distilled. Furthermore， at the begining of reaction， there was seen a good deal of reddish-violet material which seems the product， and in the end， there was much transparent one which seemed the reactant. For the inspection of this product， the usual fiask was used for the high di在erenceof boiling point ()f these components， (except for the case of molecular silver catalyst)， but it could not be distilled for the scanty of the product， so silicon in each fraction was weighed by the Direct Acid Digestion ，Method九For these experiments， commercial benzene was used and metalIic silicon (Si 93.6%， Fe 1.82%， Ca 1.41%， Al 2.50%， Mn 0.37%， Mg 0.38%)， was from the SHINETSU KAGAKU Co.， and powdered to 200 mesh and more. Direct Acid Digestion Method High-boiling or resinous samples which will yield '70 to 100 m.g. of silicon dioxide are weighed directly in tarred platimum oí~ Vycor crucibles， or 20 to 30 drops of the high-boiling previously noted are dropped from a weighing pipet into a tarred crucible containing 3 to 4 m.l. of 10% am-monium hydroxide. The water is evaporated， preferably by infrared lamp， and then the digestion is carried out. In either case， 4 or 5 drops of chlorobenzene， which reduces frothing on some samples， are added and the contents are agitated or warmed to the solution of the samples. Two m.1 of .15% fuming sulfuric acid are added to， the solution at room temperature. Many samples may be speeded up by addition of 0.5 m.l. of fuming nitric acid immediately following addition of the sulfuric acid. Digestion is accomplished by holding over a low自ameor by several hours heating on a micro帽Kjeldahlrack. When the mass has solidified and danger of frothing is past， the crucible is heated over a Meker burner to complate expulsion of sulfur trioxide fumes. The residue， usually black， isplaced in a mu由efor 1 hour at 800oC. Residual silicon dioxide is calculated back to silicon in the original sample. 7) -J. A. McHAHfl， p， C目SF.RVAJ日， CLAHK:“Determination of Sili巴onin Or伊 nosiliconComp叩 nd".72 H. Kimurα (b) ArrARA'rus F'OR PRECISE FRACTIONAL DISTII~LATÍON AN ALYSIS AND GENEUAL PROCEDURE The apparatus for precise fractional distilla tion analysis was the Podbielniak Packod Tower which is a partial condensation type is shown in 、Fig.2. A pyrex column C was'4.2 mm (inside diameter) x 1200 mm (hieght). On account of perfect and exact control of column thermal conditions and product-withdrawal of this air-jacketed column. It was insulated the heater by asbestos 20 mm in inside diameter. It was surrounded by the nich-rom heating wire on the outside of fractionating column. Many glass cylinders (1.5 mm in diameter， and 3 mm long) were tised in packing and their arrange-ment was at random. The twice turn wires of nickel were adopted for the higher efficiency. Then the space ratio was 66%， and reflux ratio was 50土 5.Fig. 2. Apparatus of Frac-tional DistiIlation. Ascending vapor was dephlegmated at H and with components of high boiling point were carr色dout of vaccum distil-lation. (K; M in this figure is the vaccum adoptor and the vaccum pump respectively). The theoretical plate number of this column measured 22.5 plates by means of CsH6一CC14system and hold up was 24 cι. For the research of distillate岨temperaturerelation， the values were read every one minute and the molecular weight of each fraction was measured by the cryoscopic method. In the rectificational analysis， the following notice must be generally taken， but the author considered only of (b) and (c)， and neglected the others for the constant condifions. 号) Constitution of sample and a specific chracter for distillation b) Total time for distillation 。}• DistilIation ratio， re乱uxratio， distillatory pressure and al condi-tions except for (b) d) Tenfold for the maximuIlI column volume of over-flow distillate in fractionating section area e) Effect of packing f) Adiabatic efficiency of column g) General design and construction of fractional distil1atory apparatus 、On thc Dircct S習nthcsis01 Ph肌 'ylchloros税制問 WithSeveral C'atalysts 73 (c) RESULTS Owing to the difference of catalyst preparation could be classified as follows: (1) Reduced Copper catalyst The prepar~tion of the reactant used in this experiment was as folIows， sodium silicate was prepared from the warm solution of silica gel as carrier and sodium hydroxyde diluted in :5% solution， added 5% cuppric chloride solution slowly on heating and stirring. In the end， the blue colloid of cuppric hydroxyde was precipitated. This precitate was washed by decan耐. tation until it showed no-color by phenolphthalein indicator and had very slight rea:ction of CI-in silver nitrate solution. After the powdered elementary silicon was mixed with its precipitate，自ltratedin aspirator， dehydrated with pressing， moulded and dried at about 60oC， and formed as tablets. TABLE 1 r町17l午:rlE7可唖350 I 24.5 112.2 i 4 I 44 39.2 I 50 ー 39 1ー|:::|;;:UL h:;(;:l:[;:1:|:;|;i:2|;; (2) Silver chloride catalyst In the process of this synthesis， silver chloride seemed to form as an intermediate， therefore， the author adopted it. A colIoidal silver silicate solution， which was formed from 5% solution of silver nitrate and sodium silicate， was most difficult to filtrate， there幽fore， so silver chloride was precipitated complately by the addition of a litle hydrochloric acid. And the subsquent treatment was the same as (1) TABLE 2 .山~-I川W恥削ei執桝引叩吋m…J岬''::'1 I Yield I悶F附もH由伽伽io加0ω叩n叫11.， . •. ，1 Flo-1 1 "" _ u 1 "'._ .L' ••• _， n.:_L!1LL'_.. {nh 1.._.. _ 1 Temp.1 Time 1な__"of _.J :;~~芝 1 00" 1 一「一一 l一一一一一ーォ一一丁了で-1rsi<?n 1 tio? 1h lcoHBqdL10邑 I 12: Iμ1LB.0戸jHB.l Ft酬Ir副 oI ratio 二立~_I'ιよ gーl_gLhr 1._..._1ー I一一」竺土"1 I '竺三上;1-''; I芝-400! 山 140 1 116.9 1 6.6 1 1.21 1 ~lO 1 ~102.8 I 7.0 1107・31 1.0 1 2.0 I 0.44 I 0.37 500 21.5 I 50 1 216.1 1 6.6 1 .1.18 1 218 1 100.51 33，9 1 52.71 26.5 1 2.7 1 5.83 1 2.68 500 1 9 I 40 I 179.5 I 20.4 1 1.28 1 1~93 1107.8 I 8.2 1148.2リ 7.01 - 0.6 1 0.31 600 18 ! 30 1 183.7 1 9.3 1 1.15 L 1~99 1 108.2 1 1.5 1148.0川 7.21 2.0 1 0.72 1 0.36 梧74 H. Kimum (3) Reduced silver catalyst By reason of a great e町ectof the侮reductionof reactant on the catalytic activities， the reduced copper catalyst was prepared with the same principle of copper catalyst: iιdilute sodium hydroxyde solution of silica gel was added to dilute silver nitrate solution on heating" so silver oxide was precipitated， then it was washed until it showed slightly alkaline. The subsquent treatment was the same as (1) 400 I 7.5 450 I グ500、|グ550 I グ(4) Molecular Silver catalyst. TABLE 3 40 " The preparation of the reactant used in this experiment ¥vas as follows. Silver chloride that was obtained from si1ver nitrate was washed fil the NO;-was disappeared and then it was reduced with the nascent hydrogen which was produced by the reaction of much dilute sulfuric acid. and zinc powder. Thus， the so-called moleeular silver was obtained. In this operation， to avoid of oxygen， the hydrogen gas was bubbled ahd washed with hot distilled wa ter tilI SO:; -was disappeared. Then this catalyst was mixed with the elementary silicon that was preserved in hydrogen gas， and then dried in vaccum and used for sample in powder about 100 g. . TABLE 4 主zJ l 1 24 30 2.5 i 18.7 I 56.7 1.82 36.4 i 4.26 I 2.16 0.3 2.42 9.0 1 η 50 4.1 30.4 55.3 16.3 17.1 2.18 2.18 1.09 2.0 9.5 500 1 1 " 1 28.1 51.3 20.0 13.1 5.46 1.09 1.46 1.82 17.0 350 10 1 1 1 :34.6 62.9 13.4 26.2 8.73 1.46 182 1.63 19.3 400 η /J " 24凶8I 6.19 3.64 4.73 - I 1.46 I 20.7 450 I! !J !J グ im682273 1091397 5.1 7.45 。73I 1.09 I ]9.3 500俳 1/ 1/ I! ]3.8 ! 4.73 5.27 ふ83!沙門lm2211600 1/ 1/ 1/ グ :34.4I 71.8 I 21.8 10.2 I 4.37 10.9 4.73 脅働On the Direct Synthesis of Phenylchlorosilαnel! With S.ωeral Catalysts 75 (d) DISCUSSlON 1) On the kinds of catalyst In the above four catalysts， the redueed silver (10% by weight) catalyst and molocular silver (10% by weight) catalyst are considered to be favou-rable， namely di古eringfrom other catalysts the reaction is contineous and the product per unit reactant is much， but as a defect it has high carbonization. Silver chloride catalyst has low carbonization， but cannot react conti圃neously; on the other hand， the product at initial is more than at final. With the molecular silver catalyst it is obtained that the yield depends upon the preparIng process (on account of 0ふ2) The most available temperature The following results are obtained in this experiment. In the case of silver chloride catalyst， the reaction begins at 4000C and is in the best condition a t 5000C. Reduced silver catalyst has the highest e自ciencyat 5000C. Molecular silver catalyst begins at 3500C， but the yield is constant at 5000C. In 6000C t.e reaction rate becom:es to decrease rapidly for the carbonization. 3) On the products With reduced copper catalyst it is considered that the reaction is the synthesis of phenylchlorosilanes rather than the decomposition of chloro-benzene， because the components of low specific gravity， low boiling point are mainly producted. But， with silver chloride catalyst， of the白rsttime of reaction there are produced a good deal of such componentョofhigh boling point which have high speci五cgravity and high silicon content. On the other hand， at the last time of reaction， there is much diphenyl. With reduced silver catalyst， itis shown by the above meassurement that the resultant is formed on an average. On the case of molecular siIver catalyst which is shown the highest efficiency， itis explained as follows: with 1% of the catalyst， the reaction rate is increased with temperature， because the decomposition and polymeri-zation is accelarated with temperature， then the components of low boiling point and diphenyl is increased. In this case， the main product R2SiC12 1s about constant at higher temperature then 3500C (see Fig. 3). With 10% of the cata1yst， the higher the temperature， the more the components of high boiling point until at 5000C， and at the same time， the 1ess the RSiCI:l， the more the diphenyL In this content the R2SiCl2 has the maximum e伍ciency(8%) at 4500C. 76 % ‘〉3~O 400 今今o 500 TEMPERATυRE 写50O C ら00H. Kim1.ιra In the end， this molecular siIver is one of .the best catalysts for the preparation of phenylchlorosiIanes， because of the totaI efficiel1cy being reached to 20%. (see Fig. 3) 4) On the flowing velocity. The greater the velocity， the Iess the reaction rate and the more the carbonization may be carried out. The satisfactory value seemed to be 5，-12 gjhr. Fig. 3. Tbe cbange of composition with the reaction temperature 5) On the rectifying distiIation. U sing the above mentioned ap-paratus by which temperature圃controlis very di自cult，and that with such a reflux ratio， the good plate curve is scarcely obtainable in normal distillation， but it is made in the carefulI vacuum distillation which is shown in Fig. 4， Fig. 5， Fig. 6， and Fig. 7‘ 円、，色、JIREACTJON TE円PERATURE3001 ¥ WE IGHT 0下 CATALVST3SOC. 105}-.ι200 z 。10 20 → WEI6tlT (宮}Fig. 4. 3川 (RMCihp 4ヨ0"ιWEIGけT()十 CAT IO~ 300 R，SICi2 l品。∞d30 Rゃla (3弘一(j)/~O~ R，SI(Q三o._ 200 l20 回coεlt 20RSl 2乙 16' w {H5!J日ー← t 10 128C6H，cι J 。10 20 ♂ 30 → WEIGHT (~) Fig. 6. 301 J REAιTIOM TEMPι ¥WEIGH10F (AT 4ω@ζ 10す131 C6H，α 。10 20 - WEI6HT (31 Fig. 5. |仇工 n~ 300 、Jc. ~2ω ← 10 。10 20 -.. Wfl(jH T (~) Fig. 7. 30 30 However， the column with higher efficiency is necessary for. the components of low boiling point. On the Direct Synthsis of Phe仰 lchlorosil側 esW倣島型的・alCatalysts 77 Summ.ary The author carried out the synthetic experiments for direct synthesis of phenylchlorosilanes， and concluded the most available conditions in these reactions (such as kinds of catalyst， reaction temperature， and etc.) by using reduced copper， silver chloride， reduced silver， and molecular silver catalyst. These experiments lead to the conclusion that the yield of direct synthesis is worse than the substitution method (such as GRlGNARD回method)for phenylchlorosilanes. And yet， by applying rectificational analysis， the author obtained successful results. The author wishes to express his hearty thanks to Dr. T. YAlIfADA， E. YASUNAGA and his co-workers (Electrotechnical Laboratory) for their kind guidance and aid in this work and to Professor M. SHINDO for his kind advice in this report. Finally it must be mentioned that this stl1dy of mine is entirely thanks to the Grants in aid of Scientific Research (don，ated by the Ministry of ' Education). (Received Oct刀ver，31， ]950.，) 

On the Direct Synthesis of Phenylchlorosilanes With Several Catalysts and Fractional Distillation Analysis

Abstract

Similar works

Full text

Available Versions

Muroran-IT Academic Resource Archive