Europâisches Patentamt

® European Patent Office @ Publication number: 0 068 795 Office européen des brevets B1

® EUROPEAN PATENT SPECIFICATION

® Date of publication of patent spécification: 13.03.85 © Int. ci.4: C 07 C 69/15, C 07 C 67/297 @) Application number: 82303245.3 (22) Date offiling: 22.06.82

(54) Process for producing .

(§) Priority: 22.06.81 JP 96296/81 ® Proprietor: MITSUBISHI GAS CHEMICAL COMPANY, INC. 5- 2, Marunouchi 2-chome Chiyoda-Ku (§) Date of publication of application: Tokyo (JP) 05.01.83 Bulletin 83/01

(72) Inventor: Isshiki, Tomiya (45) Publication of the grant of the patent: 14-11 Umegaoka 2-chome 13.03.85 Bulletin 85/1 1 Setagaya-ku Tokyo (JP) Inventor: Nawata, Takanari 19-3 Kanamachi 5-chome (84) Designated Contracting States: Katsushika-ku Tokyo (JP) DEFRGBIT Inventor: Kijima, Yasuhiko 641 Kode Matsudo-shi Chiba-ken (JP) (5$) References cited: Inventor: Ito, Akira FR-A-2 413 354 15-6 Nishikubo-cho Tokiwadaira US-A-2 425 389 Matsudo-shi Chiba-ken (JP) Inventor: Watanabe, Takayuki 6- 1 Kanamachi 1-chome 0Û Katsushika-ku Tokyo (JP) m (74) Representative: Ritter, Stephen David et al N Mathys & Squire 10 Fleet Street London EC4Y 1AY (GB) oo o o Note: Within nme months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall Û. be filed in a written reasoned statement. It shall not be deemed to hâve been filed until the opposition fee has been (Art. UJ paid. 99(1 ) European patent convention). Courier Press, Leamington Spa, England. (4) ammonium halides represented by NH4X wherein X is as defined above. This invention relates to a process for The mechanism of the decomposition of producing vinyl acetate which comprises ethylidene diacetate for forming vinyl acetate is decomposing ethylidine diacetate, and par- not perfectly clear. However, it is believed that ticularly relates to a process for producing vinyl the decomposition reaction is expressed by the acetate which comprises carrying out decom- following equation: position of ethylidene diacetate in the presence of a catalyst comprising at least one compound selected from the group consisting of fluorides, chlorides, bromides, iodides, halogens and The above reaction proceeds in a good state mixtures thereof. when a catalyst comprising a halide referred to Vinyl acetate has been produced from above is used. acetylene in the past. Recently vinyl acetate has As indicated, the halides which are usable as also been produced from ethylene. the catalyst in the practice of this invention are In addition, a process for producing vinyl bromides, iodides and mixtures thereof, iodides acetate which comprises producing ethylidene being most preferable. diacetate (1,1-diacetoxy ethane) from acetalde- Examples of the halides which are used as hyde and , or dimethyl ether or the catalyst of this invention include the follow- methyl acetate and synthesis gas and causing ing. However, compounds which are not listed decomposition of the ethylidene diacetate to in the following paragraphs may also be used as form vinyl acetate (refer to Hydrocarbon the catalyst. Process, 44, (11) 287 (1965), British Patent (1) Lithium halides, including LiBr, No. 1,538,782 and U.S. Patent Nos. 2,021,698; LiBr2 . 2H2O, Lil and Lil · 3H2O. 2,425,389 and 2,860,159). However, known (2) Magnesium halides, including MgBr2, processes for decomposing ethylidene MgBr2 · 6H2O, Mgl2 and Mgl2 . 8H2O. diacetate were unsatisfactory. (3) Calcium halides, including CaCl2, CaBr2, In the prior art, protonic acids, such as Cal2, CaBr2. 6H2O and Cal2 · 6H2O. sulfuric acid, organic sulfonic acids, etc. have (4) Strontium halides, including SrBr2, Srl2, been known as catalysts for decomposing and SrBr2 . 6H2O. ethylidene diacetate. Decomposition of ethyli- (5) Barium halides, including BaBr2, Bal2 and dene diacetate by using such catalysts is BaBr2. 2H2O. unsatisfactory in respect of decomposition rate (6) Zinc halides, including ZnBr2 and Znl2. and selectivity to product. (7) Tin halides, including SnBr2, SnBr4, The present inventors carried out research to SnBr212, Snl2 and Snl4. find a process for efficiently producing vinyl (8) Antimony halides, including SbBr3, Sbl3, acetate from ethylidene diacetate. As a result, Sbl5 found novel catalysts for decomposing we The metal halides be in the state of a ethylidene diacetate to form vinyl acetate. This may hydrate, a double salt or a coordination invention is based this discovery. on compound. Mixtures of two or more metal is An object of this invention to provide a halides may be used. The metal halides may be process for producing vinyl acetate in a high in the form of solid material, powder or finely decomposition rate and in a high selectivity. divided powder. The metal halides may be sup- According to the present invention there is ported on a carrier. Metal halides supported on provided a process for producing vinyl acetate a carrier can easily be separated from the which comprises decomposing ethylidene reaction system. diacetate in the presence of at least one halide (9) Organic halides represented by R1Xp. selected from: wherein p is integer of 1-3 and X is as (1) metal halides selected from metal defined above including: bromides and iodides, and mixtures (a) Compounds wherein R1 is thereof, said metal being selected from saturated alkyl having 1 to 10 Li, Mg, Ca, Sr, Ba, Zn, Sn and Sb; carbon atoms or cycloalkyl having (2) organic halides represented by R1Xp 3-10 carbon atoms, for example wherein R1 is selected from alkyl having CH3Br, CH2BR2, CHBr3, CH31, 1-10 carbon atoms, cycloalkyl having CH2l2, CHl3, CH3CH2Br, CH3CH2l, 3-10 carbon atoms and aromatic ICH2CH2l and C6H11l. hydrocarbon having 6-10 carbon (10) Organic halides represented by R2COX atoms, X is selected from I and Br, and p wherein R2 is saturated alkyl having 1- is 1, 2 or 3; 10 carbon atoms, cycloalkyl having 3- (3) organic halides represented by R2COX 10 atoms or aryl and X is as defined wherein R2 is selected from alkyl having above including CH3COBr, CH3COl, 1-10 carbon atoms, cycloalkyl having CH3CH2COl, C6H11COl and C6H5COl. 3-10 carbon atoms and aryl, and X is as defined above; and Of the metal halides, halides of metals selected from Li, Mg, Ca, Sr, Ba, Zn, Sn and Sb another solvent is not necessary. However, the following, namely Li, Mg, Ca, Sr, Ba and Sb other organic solvents compatible with ethyli- are most preferred. dene diacetate and products under the reaction The amount of catalyst employed depends conditions may be used. Compounds which on whether the catalyst is soluble, insoluble or participate as solvent in the reaction as a partially soluble in the reaction system, or starting material, an object product or a by- whether the reaction is carried out in a fluidized product are preferable. For example, ethylidene or fixed bed when using an insoluble catalyst. In diacetate and acetic anhydride are preferable. general the amount of the catalyst employed Solvents which are usable in this invention may be in the range of 1 x 10-4-90 wt%, pre- include, for example, organic acid esters, such ferably 5xlo-1-85 wt %, most preferably as ethylene glycol diacetate, propylene glycol 1 x 10-2-80 wt % and most preferably 0.1- diacetate, methyl acetate, dimethyl adipate, 75 wt % on the basis of weight of the reaction methyl benzoate, ethyl benzoate, dimethyl solution. phthalate, diethyl phthalate, dioctyl phthalate, In practicing this invention, the reaction phenyt acetate and tolyl acetate; hydrocarbons, temperature is not critical. In general, the such as dodecane, hexadecane, benzene, reaction temperature may be within the range naphthalene, and biphenyl; inorganic acid of 20°C-500°C, preferably 60°C-350°C, esters, such as triphenyl phosphate, tricresyl more preferably 89°C-250°C and most phosphate, dibutylphenyl phosphate, tetra- preferably 80°C-200°C. methyl ortho silicate, and tetrabutyl silicate; Ethylidene diacetate which is used as a raw aromatic ethers, such as diphenyl ether; and material in this invention may be prepared by ketones, such as acetone, methyl ethyl ketone, reacting with acetic anhydride, or dibutyl ketone, methyl isobutyl ketone, aceto- by reduction reaction of acetic anhydride with phenone and benzophenone. hydrogen. Alternatively, ethylidene diacetate It is desirable in the present invention that the may be prepared by reacting dimethyl ether or concentration of vinyl acetate, which tends to methyl acetate with synthesis gas as disclosed cause polymerization, be maintained at a low in Japanese Patent Publication (Kokai) Nos. level by separating the vinyl acetate from the 62045/1980, 110647/1981. and 45884/1980 reaction system. For example, it is suitable to and British Patent No. 1,538,782. Acetalde- maintain the concentration of vinyl acetate in hyde, acetic anhydride, dimethyl ether, methyl the reaction system at less than 25 wt % by acetate, methyl iodide, etc. may be incor- continuously withdrawing (for example distill- porated in ethylidene diacetate prepared by ing) the resulting vinyl acetate from the reaction such methods. However, the ethylidene system and it is preferable to maintain the diacetate containing the components in such an concentration at less than 15 wt %. amount that the components are usually incor- Retention of large amount of the , porated in ethylidene diacetate, that is the which is formed as a by-product in the reaction ethylidene diacetate containing small amount of system, should be avoided. The reason is that the components can be used as a raw material acetic acid tends to prevent formation of the in this invention. object product. So, in general, the concen- In general, water may be incorporated in the tration of acetic acid in the reaction system may reaction system. Ethylidene diacetate con- be no more than 50 wt %, preferably less than taining low concentration of water is permitted 40 wt %, more preferably less than 30 wt % and in this invention. The presence of water of more most preferably less than 20 wt %. than 10 mol % on the basis of weight of a It is preferable that the decomposition of reaction solution is not preferable in this ethylidene diacetate is carried out while con- process, because such a large amount of water tinuously withdrawing from the reaction system causes decomposition of the starting material vinyl acetate and acetic acid formed. Vinyl and the object product. acetate and acetic acid may be withdrawn from In general, water content less than 5 mol % is the reaction system by distillation. Withdrawal preferable, and water content less than 3 mol % of vinyl acetate acetic acid can be made by is more preferable. Water is not formed in the withdrawing some of the reaction solution con- reaction. So, substantially anhydrous con- taining vinyl acetate and acetic acid from the ditions can be maintained by keeping the reaction system. starting material and other components added The following examples 1, 2, 6-10, 17, 20, to the reaction system dry. 22, 24, 26 and 28-31 are given as illustrative The present process may be carried out in embodiments of the invention and should not gaseous or liquid phase. The present process be construed as limiting its scope. All parts and may be carried out by batch, semi-continuous or percents are by weight, unless otherwise continuous method. When using catalysts specified. insoluble in the reaction system, either fluidized bed or fixed bed may be used. Example 1 Since ethylidene diacetate (starting material) Into a reactor were charged 135 grams of and vinyl acetate (object product) serve as a ethylidene diacetate and 4.5 g of lithium iodide. solvent for the reaction of the present invention, After the reactor was purged with nitrogen, the reactor was sealed. The reaction was carried Examples 2-27 out at 175°C for 90 minutes with stirring. After The procedures of Example 1 were repeated cooling, analysis showed that 5.56 g of vinyl by using the reaction conditions and the acetate and 3.96 g of acetic acid were formed. components as given in Table 1. Example 28 3-10 carbon atoms and aromatic Into a reactor were charged 75 g of ethyli- hydrocarbon having 6-10 carbon dene diacetate, 75 g of acetic anhydride and atoms, X is selected from I and Br, and p 4.5 g of barium iodide dihydrate. The reaction is 1, 2 or 3; was carried out at 175°C for 90 minutes. 4.76 (3) organic halides represented by R2COX g of vinyl acetate was formed. wherein R2 is selected from alkyl having 1-10 carbon atoms, cycloalkyl having Example 29 3-10 carbon atoms and aryl, and X is Into a reactor equipped with agitating blade as defined above; and and filter were charged 1 5 g of barium iodide (4) ammonium halides represented by NH4x dihydrate and 135 g of ethylidene diacetate. wherein X is as defined above. After the reactor was purged with nitrogen, the 2. A process as defined in Claim 1 wherein reaction was carried out at 175°C for 15 said metal halide is a metal iodide. minutes. The reaction was further carried out at 3. A process as claimed in Claim 2 wherein 175°C for 3 hours while continuously feeding the metal constituting said metal halide is ethylidene diacetate into the reactor at a rate selected from Li, Mg, Ca, Sr, Ba and Sb. of 500 g/hour and continuously withdrawing 4. A process as claimed in Claim 1 wherein the reaction solution from the reactor through said metal halide is selected from Lil, LiBr, Mg12, the filter. 32.2 g of vinyl acetate was obtained MgBr2, Cal2, CaBr2, Srl2, SrBr2, and BaBr2' by distilling the reaction solution withdrawn 5. A process as claimed in any preceding from the reactor. claim wherein the amount of halogen or halogen compound employed is in the range of Example 30 1 x 10-4-90% by weight on the basis of weight Into an autoclave were charged 105 g of of a reaction solution. ethylidene diacetate and 40 g of barium iodide 6. A process as claimed in any preceding dihydrate. The autoclave was closed. The claim wherein the reaction is carried out while contents in the autoclave were heated and withdrawing some of the reaction solution stirred at 160°C for 14 minutes. Mixture of from the reaction system. ethylidene diacetate and acetic anhydride 7. A process as claimed in any preceding (37:63 by weight) was fed at rate of 42 g/hour claim wherein the reaction is carried out while into the autoclave with stirring while main- withdrawing vinyl acetate and/or acetic acid taining the contents at 160°C and at the same from the reaction system. time vapor was withdrawn from the autoclave 8. A process as claimed in Claim 7 wherein at rate of 42 g/hour. The operation was vinyl acetate and/or acetic acid is withdrawn by continued for 6 hours. 26.5 g of vinyl acetate distillation. was obtained by distilling the distillate. 9. A process as claimed in any preceding claim wherein the reaction is carried out while Example 31 maintaining the concentration of vinyl acetate Into an autoclave were charged 105 g of at less than 25% by weight by withdrawing vinyl ethylidene diacetate, 195 g of acetic anhydride acetate from the reaction system. and 40 g of lithium iodide. The autoclave was 10. A process as claimed in any preceding closed, and heated. The contents in the auto- claim wherein the reaction is carried out while clave were stirred at 160°C for 19 minutes. maintaining concentrations of acetic acid at less Mixture of ethylidene diacetate and acetic anhy- than 50% by weight by withdrawing acetic acid dride (37:63 by weight) was fed at rate of 57 from the reaction system. g/hour into the autoclave with stirring while 11. A process as claimed in any one of maintaining the contents at 160°C and simul- Claims 1 to 10 wherein the reaction tempera- taneously vapor was withdrawn from the auto- ture is between 20 to 500°C. clave at rate of 57 g/hour. The operation was continued for 7.5 hours. 53.2 g of vinyl acetate was obtained by distilling the distillate. 1. Verfahren zur Herstellung von Vinylacetat durch Zersetzen von Ethylidendiacetat in Gegenwart mindestens eines Halogenids, 1. A process for producing vinyl acetate bestehend aus: which comprises decomposing ethylidene 1. einem aus einem Metallbromid und/oder diacetate in the presence of at least one halide -jodid bestehenden Metallhalogenid, selected from:- wobei das Metall aus Li, Mg, Ca, Sr, Ba, (1) metal halides selected from metal Zn, Sn oder Sb besteht; bromides and iodides, and mixtures 2. einem organischen Halogenid der Formel thereof, said metal being selected from R1Xp, worin bedeuten R1 eine Alkyl- Li, Mg, Ca, Sr, Ba, Zn, Sn and Sb; gruppe mit 1-10 Kohlenstoffatom(en), (2) organic halides represented by R'Xp eine Cycloalkylgruppe mit 3-10 Kohlen- wherein R1 is selected from alkyl having stoffatomen oder eine aromatische 1-10 carbon atoms, cycloalkyl having Kohlenwasserstoffgruppe mit 6-10 Kohlenstoffatomen; X J oder Br und p 1, 2 d'éthylidène en présence d'au moins un halo- oder 3; génures choisi parmi: 3. einem organischen Halogenid der Formel (1) des halogénures de métal choisis R2 parmi R2COX, worin für eine Alkylgruppe mit des bromures et iodures de 1 eine métal, et leurs bis 10 Kohlenstoffatom(en), Cyclo- mélanges, ledit métal étant choisi mit 3 bis 10 Kohlenstoff- parmi alkylgruppe Li, Mg, Ca, Sr, Ba, Zn, Sn et Sb; oder eine steht und X atomen Arylgruppe (2) des halogènures organiques repré- die besitzt oder. angegebene Bedeutung sentés R'Xp où R1 est choisi parmi 4. einem Ammoniumhalogenid der Formel par un alcoyle 1 à 10 atomes de worin X die angegebene ayant NH4X, carbone, 3 à 10 besitzt. un cycloalcoyle ayant Bedeutung atomes de carbone 2. Verfahren nach Anspruch 1, dadurch et un hydrocarbure aromatique 6 à 10 atomes de gekennzeichnet daß das Metallhalogenid aus ayant carbones, X choisi einem Metalljodid besteht. est parmi et Br et p est 1, 2 3. Verfahren nach Anspruch 2, dadurch ou 3, (3) des gekennzeichnet, daß das Metall des Metall- halogènures organiques représentés R2COX où R2 choisi halogenids aus Li, Mg, Ca, Sr, Ba oder Sb par est parmi un besteht. alcoyle ayant 1 à 10 atomes de carbone, un cycloalcoyle 3 à 10 de 4. Verfahren nach Anspruch 1, dadurch ayant atomes carbone et un et X est tel gekennzeichnet, daß das Metallhalogenid aus aryle, que défini ci-dessus; LiBr, et LiJ, MgJ2, MgBr2, CaJ2, CaBr2, SrJ2, SrBr2 (4) des oder besteht. halogènures d'ammonium repré- BaBr2 sentés 5. Verfahren nach einem der vorherge- par NH4X où X est tel que défini ci-dessus. henden Ansprüche, dadurch gekennzeichnet, 2. Procédé selon la daß die Menge an verwendetem Halogen oder revendication 1 où ledit de métal verwendeter Halogenverbindung im Bereich von halogènure est un iodure de métal. 1 x 10-4 bis 90 Gew.-% auf der Basis des 3. Procédé selon la revendication 2 où le Gewichts einer Reaktionslösung liegt. métal constituant ledit halogènure de métal est 6. Verfahren nach einem der vorher- choisi parmi Li, Mg, Ca, Sr, Ba et Sb. gehenden Ansprüche, dadurch gekenn- 4. Procédé selon la revendication 1 où ledit zeichnet, daß die Reaktion unter Abziehen von halogènure de métal est choisi parmi Lil, LiBr, etwas Reaktionslösung aus dem Reaktions- Mg12, MgBr2, Cal2, CaBr2, Srl2, SrBr2, et BaBr2. system durchgeführt wird. 5. Procédé selon l'une quelconque des 7. Verfahren nach einem der vorhergehenden revendications précédentes où la quantité de Ansprüche, dadurch gekennzeichnet, daß die l'halogène ou du composé halogèné employé Reaktion unter Absziehen von Vinylacetat est comprise entre 1 x 10-4 et 90% en poids sur und/oder Essigsäure aus dem Reaktionssystem la base du poids d'une solution réactionnelle. durchgeführt wird. 6. Procédé selon l'une quelconque des 8. Verfahren nach Anspruch 7, dadurch revendications précédentes où la réaction est gekennzeichnet, daß Vinylacetat und/oder effectuée tout en retirant une partie de la Essigsäure durch Destillation abgezogen wird solution réactionnelle du système réactionnel. (werden). 7. Procédé selon l'une quelconque des 9. Verfahren nach einem der vorherge- revendications précédentes où la réaction est henden Ansprüche, dadurch gekennzeichnet, effectuée tout en retirant l'acétate de vinyle daß die Reaktion unter Aufrechterhaltung der et/ou l'acide acétique du système réactionnel. Vinylacetatkonzentration auf weniger als 25 8. Procédé selon la revendication 7 où Gew.-% durch Abziehen von Vinylacetat aus l'acétate de vinyle et/ou l'acide acétique est dem Reaktionssystem durchgeführt wird. retiré par distillation. 10. Verfahren nach einem der vorherge- 9. Procédé selon l'une quelconque des henden Ansprüche, dadurch gekennzeichnet, revendications précédentes où la réaction est daß die Reaktion unter Aufrechterhaltung der effectuée tout en maintenant la concentration Essigsäurekonzentration auf weniger als 50 de l'acétate de vinyle à moins de 25 % en poids Gew.-% durch Abziehen von Essigsäure aus en retirant l'acétate de vinyle du système dem Reaktionssystem durchgeführt wird. réactionnel. 11. Verfahren nach einem der Ansprüche 1 10. Procédé selon l'une quelconque des bis 10, dadurch gekennzeichnet, daß die revendications précédentes où la réaction est Reaktionstemperatur zwischen 20 und 500°C effectuée tout en maintenant les concen- liegt. trations de l'acide acétique à moins de 50 % en poids en retirant l'acide acétique du système réactionnel. 11. Procédé selon l'une quelconque des 1. Procédé de production de l'acétate de revendications 1 à 10 où la température de la vinyl qui consiste à décomposer du diacétate réaction est comprise entre 20 et 500°C.