TWI289548B - Process for production of hexafluorobutadiene and 1,2-dichlorohexafluorocyclobutane - Google Patents

Abstract

Method for preparing hexafluorobutadiene is carried out by pyrolysis of chlorotrifluoroethylene followed by dechlorination of 1,2-dichlorohexafluorobutene-3 in the presence of zinc in a solvent. The parent chlorotrifluoroethylene is subjected for pyrolysis at temperature from 505 DEG C to 600 DEG C. Prepared pyrolysate is condensed at temperature from 0 DEG C to -10 DEG C and then condensate is rectified to isolate fraction boiling at 59.0-59.5 DEG C and containing 1,2-dichlorohexafluorocyclobutane (C4F6Cl2). Fraction boiling at 63.5-64 DEG C and containing 1,2-dichlorohexafluorobutene-3 is subjected for dechlorination in polar solvent medium at temperature 37-50 DEG C. Compounds not condensed at the condensation stage are recovered to pyrolysis. Method provides carrying out pyrolysis of chlorotrifluoroethylene with conversion 50-70% and to obtain hexafluorobutadiene and 1,2-dichlorohexafluorocyclobutane simultaneously. Method exhibits technological effectiveness and involves essentially 3 main stages only.

Description

1289548 IX. Description of the invention: [Technical field to which the invention pertains] The invention relates to a method for producing a monomer-containing and cyclized cyclic compound, and more particularly to a process for producing hexafluoro-organicene and 1,2-dichloro The method of hexafluorocyclobutane (C4Cl2F6-ring). [Prior Art] The hexafluorobutadiene having the formula C4F6 or CF2 = CF-cf = cf2 is widely used in microelectronics for the manufacture of 1C devices, and is also used for the production of various copolymers. % + π - - qi six-form ring Ding Xuan can be used for anesthesiology or as an intermediate in organic synthesis. 1,2-difluorohexafluorocyclobutane is mainly produced by the polymerization of chlorotrifluoroethylene (C2F3CI). U.S. Patent No. 2,404,374 (C1. 570-132, published July 23, 1946) and No. 2, 436, 142 (C1. ^70-132, published February 17, 948) The polymerization of vinyl fluoride at a high pressure (60-80 atm) of 200-220 ° C gives a C4C12F6-ring. U.S. Patent No. 5,763,703 (Cl. C07C 017/00; C07C 017/25, June 9, 998) discloses the dimerization of chlorotrifluoroethylene at 300 - 400 C at 2 - 4 atm. C4C12F6-ring. The thermal decomposition of C2F3C1 at atmospheric pressure is described in S. M. Ivanova, Ν·V·Zem1yanskaya et al. in Zhurnal Obshchey Khimii, Vol. 56, Vyp. 2, pp. 357-364, 1986. It shows the pyrolysis products formed at 450-710 °C and at different temperatures, showing the relationship between the main product content and the process temperature. It also shows that the pyrolysis of C2F3CI will form two main products: C4CI2F6-ring and C4F6Cl2-line type. (CF2 = CF-CFC1-CF2CI, ie 1,2-dichlorohexafluorobutane-3).

Fluorine Chem., pp. 1, 986, 31 (4), 5 1289548 5113⁄49 discloses a method for the addition of dibromotetramethane (RU4B2) = addition to chlorotrifluoroethylene (yield 38%). f IV "4-chloro-1,1,2,3,4,4-hexafluorobutane is dehalogenated to make > hexafluorobutadiene C4F6. Ting ^ branch, also known in the middle · · The method for the manufacture of hexafluorobutadiene will give a low yield of the target compound. It is disclosed in the 200th No. 114710 (C1·C07C 0 1 7/263, published in 1959). The method comprises several steps: - catalytic isomerization of CF2BrCF2Br to obtain CFBr2CF3; - reaction of CFBnCF3 with zinc in an aprotic solvent to form (CF 2 = CF - ) 2 Ζ η ; - (CF2 = CF-) 2 Ζ Compounds containing iron (I π ) and copper (11) are reacted in an aprotic solvent to form C4F6. U.S. Patent No. 2,777,004 (C1·260-653, 1>957 f published on January 8) A method for continuously producing hexafluorobutadiene from symmetrical dichlorodifluoroethylene is described, which comprises the following steps: 1. Dimerization, which is carried out at 275 ° C and 2·8 MPa for 5-8 hours. The selectivity provided by this step is 87.3%, the conversion rate is 86.8%, and the yield is 75.8%, CFC1=CFC1 ->CFC1=CF-CFC1-CFCI2; 2. Photochemical chlorination reaction, which provides Conversion rate of 96·丨% and selectivity of 99. 4%; CFC1=CF-CFC1~CFC12 + Ch ->CFCh-CFCl-CFCl-CFCh; 3. Fluorination reaction at 250 ° C, yield 89.6%, CFCI2-CFC1-CFC1-CFCL· + SbF£l2 CF2CI-CFCI-CFCI-CF2CI ; 4 · Desulfurization of CF2CI-CFC1-CFC1-CF2C1 in a polar solvent under the action of zinc The formation of hexafluorobutadiene has a selectivity of 93.7% and a conversion of 90.2%. Each step of the synthesis is accompanied by fractionation and separation of the corresponding product, which doubles the number of steps. U.S. Patent No. 2,894,042 ( Cl. C01C21/20, 1289548 3, Hf, 7 J3 fabric) discloses an improved method for the formation of hexafluorobutadiene from symmetrical dichlorodi 5 ϋ i. This method makes the presence of t 70 in the presence of fluorine. The production method of chlorodifluoroethylene (^Ρ, ΐ^Γϊ^2,3,4-tetrachlorohexafluorobutanthrene CF2C1) is carried out in the range of -70 °C, and the production of giant compounds ^, 30 to 40% range. The main by-products are five chaos and five f. Ding C: F5C15 and hexachloro-^^-tetrafluorobutane" 2" 彳 / t paid 1,2,3,4-tetrachlorohexafluorobutene in Ϊ / I in the presence of a polar solvent The previous technique of the invention was based on the prior art of decoupling "the production of six gas butadiene with a yield of 9 〇 · 5%. . When the C2F3 and C1 are pyrolyzed to form a ruthenium, 2-dichlorohexa$ dechlorination method, the dechlorination step is completed in the presence of zinc in the ftn^ solvent (Sintezy rganicheskikh soedinenii, Ed M-Khiraia^ 1 973 ^ The yield provided by this method is very low. The common disadvantage of the method of hexa-butadiene described in right circumstance is that there is a step of the mixture and the yield of the target compound is low. [Summary of the Invention] A method of making hexafluorobutanol for women and 4 chlorohexafluorocyclobutane is provided, which is practical and includes a few steps. The present invention provides a method for producing butyl hexafluorobutane, which comprises the agent The pyrolysis of the gas trifluoroethylene is carried out, followed by dechlorination of the SJ work _3, and the initial chlorotrifluoroethylene is a pyrolysis calendar of 505 to 600 ° C. 5 ΐ i, recorded will be obtained The pyrolyzate is fractionated in a pyrolyzate of rc to -1 〇 'Uq , , , ° to separate a distillate having a boiling point of 0-59.5 C and containing ruthenium, 2 -dichlorohexafluorocyclobutane 1289548 a fraction having a boiling point of 63.5-64t and containing 1,2-dichlorohexafluorobutan-3 in a temperature range of 37 to 5 Torr in a polar solvent Dechlorination is accepted. The uncondensed product during the condensation of the pyrolyzate is recycled to the pyrolysis step. The method allows the pyrolysis step to be carried out at a conversion rate of 50-70%, and the separation of the pyrolyzate is obtained. Commercialized 丨, 2 袅 袅, 环 烧 烧 and I, 2 - dichloro hexafluorobutene -3, let 1,2-dichlorohexafluorobutene - 3 accept dechlorination to get coarse six Fluorobutadiene. The crude hexafluorobutadiene is fractionated to give a commercial product. Therefore, the method of the present invention comprises the following steps: · Pyrolysis in a temperature range of 505 to 600 ° C, resulting in C ^FeCl2-ring and C^FeCl2-linear formation, CF2=CFC1 C4F6Clr ring+CF2=CF-CFC1-CF2C1 + by-product

De-halogenation of GFECl2-line type, 2 · Separation of pyrolysis products to separate and C4F6Cl2-line type (99·9%); 3. C4F6CI2-Findion CF2=CF-CFC1-CF2CI + Zn-> in polar solvent CF2=CF-CF=CF:

ZnCL· ;

[Embodiment] The method of the present invention is carried out as follows. One step: the pyrolysis system of chlorotrimethylene from ^ CF2 = CFC1 occurs in 〇 7 - 9 0 八σ A

1289548 Ethylene and low-boiling by-products are collected or recycled to the pyrolysis step. The pyrolysis product was analyzed by the temperature f week and the use of a thermocouple to automatically "Tsvet-800" chromatography. Spoon Table 1 shows an example of a pyrolysis step. The data in the producers show that when the contact time fluctuates between 57·57 and 4·4 seconds and the reactor temperature is 54 (TC (Example 1-4), the gas = circumference is 15 to 45%, C4F6C1! ^^mmQy and tF6Cl2-, the yield of the type is 6_14%. The sheep is 8 20/〇. If the reaction temperature and contact time are on the Siit woman, the yield of the product is as follows: C4F6Ch - the first line type is 2%. In the case of the contact time of 560'C and the force of 14 seconds in Example 7, the selectivity and yield of the target are obtained. The best of the knowledge of the 5 things is '^^力古When ^~61〇t: (Example 9), Jΐi曰's Γ"The amount of boiling by-products, especially isomeric CF2 CF CFC1 CF2CI ~ CF2C1CF=CFCF2C1 CF2C1CF2CC1=CF2 The more efficient the U-method is. % purity Λίϋ times mCF2C1), its with a millimeter of stainless steel: Germany in the tube straight line: 奁j device. The external batch boiler of the columnarizer and the condensing 21 points of the first step: ~ is the basis; the number is △ 1 the first fraction of the separation I 偁 凝 condensed liquid 埶 吝 amp 人 人 人 人 人 人 人About 10% by volume of 1289548 solution of chlorotrifluoroethylene (b·ρ· (-27·8 °C)), which is accompanied by a small amount of low-point mixture (C3F5C1, c4F8-ring C^F8) The first fraction is distilled off and recycled to the pyrolysis "^ parameters: - reflux ratio (modulus of reflux): 5; - temperature at the head of the column: minus 4 - 5 °C; - steaming column temperature: 82~8 3°C; -pressure············ 2·2·Separation of the second component 59〇C, the second fraction is distilled off until the temperature is reached and then sent to destroy. Parameters: A reflux ratio (modulus coefficient of reflow): 4 〇; temperature of a head: 51 to 52. (3; a distillation column temperature: 92~93 ° C:; a pressure: 0 · 15 MPa. 2 · 3 · Dioctopus separation 2 ring and will be distilled at 59 · 2 ° C pure (99 · 9% C4F6C1 /, collected in the collection bin. Parameters: , - called k ratio (modulus coefficient of reflow) · · 1 〇〇; temperature of the head: 5 9. 〇 - 5 9. 5 ; steam column temperature · · 6 5 - 6 6 °C ; ^Pressure: 0· 005MPa (with nitrogen). <· 4·Separation of the fourth fraction. The intermediate fraction is distilled off at 59-64°C and sent to ϊίί collection. In the collection bin, then cycle to the next i parameter: ~ $ flow ratio (reflow modulus coefficient): 80 〇; the temperature of the mass is 59. 5-63. 6. (?; ~ distillation column temperature: 65- 66 ° C ; 1289548 - distillation column temperature: 65-66 ° c; - pressure: 〇 · 〇〇 5 MPa (through nitrogen). 2 · 5 · separation of the fifth fraction - linear distillation at 64 ° C pure (99 -99.9%) C4F6C12 and collect it in the collection tank. Parameters ·· - reflux ratio (modulus coefficient of reflow): 2 5 ; - temperature of the head: 6 3. 6 - 6 4. 〇; - distillation Column temperature · · 66-70 ° C ; ' - Pressure: 〇 · 〇〇 5MPa (pass 'Nitrogen' 2·6·Separation of the sixth fraction will mainly contain 1,2-one gas hexa-IIbutene-3 (〇4F6ri: a mixture of a wire and a small amount of C^Ch-isomer in U2f C distillate And collected in the collection tank, and then follow a fractionation step. Wang Wang r a parameter: - reflux ratio (reflow modulus coefficient) · 4 〇; - head temperature: 6 4 - 6 6 ° C; - distillation Column temperature: 70-75 ° C; a pressure: 0 · 005 MPa (through nitrogen). ^ ^ Residue residue is sent from the column to the destruction. 3 · J hexachlorobutane - 3 dechlorination cooling The reflow; people cry, people, women, ",, ^ ΐ orders, complete the C4F6Ch-line dechlorination. ίίϊΐίί and the solvent placed in the flask, and then through the chowder ί hunting by cold; East machine and maintained at 45t : The fat in the ίί into the gaseous C4Fe (bp5.5〇c). Use, ^ fire button ion detector Rt_x capillary tube column # by two ^00^5 J Shi 'e analysis of crude hexafluorobutadiene The mixture was analyzed by gas chromatography - gas chromatography to analyze the mixture. An example of the dechlorination step was shown in 2. The use of ethanol, 11 1289548 dimethyl decylamine and N-decyl pyrrolidone was used as the polar solvent. 2 shows the data in a large excess of zinc powder (Example 2) increases the yield of hexafluoro butadiene, but due to the increased amount of by-products containing hydrogen selectivity decreases dechlorination. Accordingly, a process for producing hexafluorobutadiene while producing 1,2-dichlorohexafluorocyclobutane is provided. The method is practical and consists essentially of three steps. 12 1289548

, L is ^ ^ ^ ^ 剞 δ 蛘 鲮铢 鲮铢 鲮铢 鲮铢 鲮铢 鲮铢 鲮铢 720 720 720 720 720 720 720 720 720 720 720 720 720 720 720 720 720 720 720 720 720 720 8.2 8.2 8.2 8.2 8.2 8.2 8.2 8.2 8.2 8.2 8.2 8.2 8.2 , diameter 4 mm, stainless steel 19.01 / 8. 84 reactor length 920 mm, diameter 4 mm, quartz crucible 20 · 16 / 13.88, L ^ ^ kj r~i <T> ^ - ◦ *itr ^ ^剠铢c3龄^飧飧54/37 45.1/ 17. 99 1 1 1 45.18/ 21.0 [ 1 45.16/ 31.09 1 ί Conversion rate of C2F3CI (8) LTD LO r-1 41.4 1 LO inch 53 44. 65 Pyrolyzate Composition, % volume. 1 mixture, total cm LO CO cz? ms 0. 69 on (five) inch CD oo CD m 1.88 mit-H inch CO arr 3.48 1 1 3. 67 1 C4F6C12-line type S CD 37.11 inch ◦ · 28.0 r-H inch cz> 33.14 4. 26 37.10 C4F6C12- Ring LO CD 51.0 o LO 47· 56 t-H 呀·43. 69 rH CD OO 42.45 C3F4CL· ! 1 V \ LO CD t-H LO CZ> 1 2 96 1 1 0· 50 1 1 2.44 1 0. 98 1-4 CaFsCl I .1 1 (XI CD LO 〇〇 CD 10.59 § 05 10.50 1 5. 89 1 3. 72 CO inch inch · C2F3CI 1 98.5 LO 〇〇 Ai S 〇〇CNJ CD T-H t-H 81.8 CO inch · 79.55 10.38 Amount of gas phase (g) LO CQ LO oa 293.4 377.0 CD 〇S *Π> -¥r Zhao·1 00 LO 呀 CD inch· oo 124.0 I CD LO Ln Contact time (seconds) Q t-H CD LO CZD 0. 98 1 ψΑ _ C ^ 500-505 535-540 535-540 535-540 C2F3C 1 quantity (g) CZ5 〇〇CO r-Η S CO CO ^ Μ τ~Ι (>a CO 13 1289548 S ΐ

The reactor has a length of 1440 mm and a diameter of 6 mm. Quartz 20.68/ 18.46 24.15/ 19.68 29. 0/ 24.76 The reactor has a length of 2880 mm and a diameter of 6 mm. Quartz 34.14/ 27.05 30. 64/ 27.01 42 72/ 35. 90 45. 62/ 37.17 41.6/ 35. 52 48. 87/ 38. 72 42. 04/ 37. 06 1 | 1 1—^ S CNl LO 卜σί CO LO 〇〇σί CO CD m 1 Liquid phase § r—1 i—( arr 1 cm 5 § CD* rH nn 1 m rH CD r—*<i—< m 1 mr oo 卜 · m OO o LO CO LO r—i 1 CO oo CD CO rH CNl t—H cn><N1 cd CO CJi CO CD LO inch LO* CO rH CD oo 1 (CD CO CO oo or—H oo inch · CO OD CD LO CO LO ◦· (NI r—H inch 03 一·················· ; inch CO rH οα CD t—H CO CO r—H t—H CD rH oa LO oo CO § r—HT—H 03 LO t—H 05 inch τ—H (NI OD CO 1 1· CO oo T— H CD o CD rH cd oo CD CO 卜 · CO i—H 05 OO CO t—H r—H CO g eg CZ5 LO CO LO t—HT—i LO oo cvi ◦ ◦ cnJ CO CO CO OO CO i—H OO cd LO st—H inch inch · <3) OD s 卜 oo CO TH CD 600-610 _____ 600-610 600-610 § LO 600-610 LO τ—Η CO oo CD r—1 CM t—H CO ◦ rH LO inch LO CO oo CD 14 1289548 〇/0>§ Article #^ 2900*6 scd6 00S006 009066 Bu 1066 19006 zod6 inch Bu CXJ6 (%)€¥ Forget € 3 ocd Bu 36 Bu 500 CO.68 ocooo oo6, zoo 6Έ8 coco·Bu oo (3. ) 铡 C COTO inch

2Y00CO CXITico 9r Bu Co OS丨0 inch OOLO—0 OS 10 § Hos SA Hos s s

s dW丨N

009 d〒N

§1 dW丨N 8S^ 0·b acolo sco sco

•I I 6CO1 6·92 cdi

SI 091

LOICO ooz i en 000

9COI 092 s,^3 mstos

OOLO 009 009 009

LfDcoco °°i9co -.s μ ICO •z 1- •s oo 1^沴 砩&--N - dM丨NI s SI —0 : Wei Wei 15 1289548 [Simple description] [Main component symbol description 】

Claims (1)

1289548 Γ ·. X. Application and ϋ藏园··· 1. A method for producing hexafluorobutadiene while obtaining bismuth, 2__dichlorohexafluorocyclobutane, including pyrolysis of chlorotrifluoroethylene, followed by zinc Degassing 1,2-dichlorohexafluorobutene-3 in the presence of a solvent, characterized in that the initial chlorotrifluoroethylene is subjected to a pyrolysis cycle in the temperature range of 5 〇 5 to 6 〇 (rc) • 5 to 15 seconds, then the resulting pyrolyzate is condensed in the temperature range of 0 to -1 (TC), and fractionated to separate the boiling point at 59.0 to 59.5. (: and contains 1 > 2 - dichloro 6 a fraction of fluorocyclobutane, and having a boiling point of 63.5-64t: and having a ruthenium, 2-dichlorohexafluorobutene-3, is in the range of 37 to 5 (). 2. The method of claim 1, wherein the unspinned product is recycled to the pyrolysis step during the cold breaking of the pyrolyzate.