DE589561C - Process for the production of non-benzene, unsaturated hydrocarbons of higher molecular weight from acetylene - Google Patents

Description

Process for the production of non-benzene-like unsaturated hydrocarbons e Higher Molecular Weight From Acetylene - The invention relates to improvements of the process of the main patent for the production of highly unsaturated not Benzene-like hydrocarbons existing polymer addition products of acetylene by using an improved catalyst mixture.

The subject of the patent 588283 is a method for carrying out the Polymerization of acetylene to unsaturated non-benzene. like hydrocarbons, such as vinylacetylene, divinylacetyleneC, Hd etc., in the presence of a suitable copper salt solution. In this process, the acetylene is polymerized when it is introduced into a catalyst, which consists of an essentially saturated aqueous solution of a cupro compound, like copper chloride; finely divided .copper, and a nitrogenous base or an ammonium salt such as chlorammonium.

One embodiment of this process relates to the continuous Preparation of acetylene polymers by adding acetylene continuously to the heated Catalyst .einleitet and the resulting polymers together with the not in reaction Acetylene that has entered is permanently removed, whereupon the finite-cracked acetylene is deposited and «is returned down to the catalyst. The ones made from a cupro salt or one equivalent of the same and an ammonium or tertiary amine salt consisting of a catalyst mixture preferably has an acidity of at least pH-6, corresponding to the dissociation of the salts in aqueous solution.

This is the case with the polymerization of acetylene according to the main patent The resulting product is a mixture of higher hydrocarbons of the acetylene series and contains divinylacetylene along with hydrocarbons of the molecular formula C1H4 and C8H8. Monovinylacetylene is included as part of the compounds of the formula C4H4 has been identified. These compounds can be separated by distillation: The present invention is a modification of that described in the main patent The object of the catalyst is higher yields of acetylene polymers per unit weight of the catalyst enables and. one: has a longer lifespan.

According to the invention, acetylene is introduced into a liquid Catalyst mixture, which consists of a cupro salt and a nitrogenous base consists, to which an acid (or a mixture of acids) is added, the Acid (or the mixture of acids) has a dissociation constant of at least io-s and is capable of forming a cuprous salt which is soluble in the mixture. Preferably the amount of acid present in the mixture is in excess compared to the amount equivalent to the base present, in such a way that a hydrogen ion concentration of at least pH - 6 results. Is it in the case of an inorganic acid added to the mixture, the existing acid should be used The ionizable hydrogen does not exceed 0.2 ounces of that present in the system Increase cupro copper. Suitable inorganic acids are hydrogen chloride, hydrogen bromide, Hydroiodic, sulfuric and phosphoric acids. On the other hand, an organic Acid can be used to replace all or part of the water, that in the original mixture or in that with an inorganic acid or a mixture mixed with inorganic acids is present. The die-carboxyl group containing organic acids according to the present modification of the invention can be added are acetic acid, chloroacetic acid, formic, citric, Tartaric, propionic, butyric or lactic acid or a mixture of one or more contains these acids.

The cupro salt can be copper chloride, bromur, iodour or cyanur. Free copper can also be present.

The ammonium or tertiary amine salt can be chlorammonium, bromammonium as - like the acetate, formate, hydrochloride and hydrobromide of pyridine, quinoline, diethylmetanilic acid, dimethylaniline, diethylaniline and quinaldine.

The reaction temperature is preferably below zoo ° C; she can ever depending on the nature of the desired product between 45 and 1000 C or at about 250 C lie; Monovinylacetylene is preferably represented at the lower temperatures.

This improvement or modification will extend the life of the Catalyst and the production of the desired substances largely increased simultaneous grazing of the formation of vinyl chloride and. other secondary addition products in essential. Amounts.

The polymerization is carried out with the aid of the modified catalyst in the same way as is described in the main patent, as can be seen from the following examples. Of course, it can also be used after the. carry out continuous procedures. EXAMPLE i A mixture is prepared which comprises 70 parts of copper chloride, 27 parts of ammonium chloride; Contains 7 parts of finely divided copper powder, 3o parts of water and a, 1 part of technical hydrochloric acid (37'1). This mixture is agitated thoroughly while introducing acetylene gas. The gas is absorbed quickly, while the temperature can rise to 50 ° C. in the course of the reaction without causing disturbances; however, it is preferable to keep it at about @ a5 ° C by suitable cooling. If one sees a slowing down of the reaction from the decrease in absorption, the introduction is interrupted, the mass 2q. Hours or longer left to their own devices, whereupon the strongly unsaturated hydrocarbons formed are depleted. let distill win. The distillation is interrupted as soon as the hydrocarbon distillate appears mixed with a lot of water. The latter is separated and returned to the reaction mass, the cooling after re-Hinzufügung- equivalent of hydrochloric acid as much as the previous over with the prepared hydrocarbon chlorine, can be used for the absorption of further acetylene. This cycle can be repeated any number of times, and a given amount of copper can be used in this way to convert an unlimited amount of acetylene. The purification of the components of this product can be accomplished by means of fractional distillation; in this way vinyl acetylene is obtained in a fraction collected between 0 ° and 10 ° C., divinylacetylene in the fraction boiling between 0 ° and 0 ° C. and higher non-benzene acetylene polymers including a tetraacetylene C8 H $ at higher boiling temperatures. The latter is expediently distilled off in vacuo.

The life of the catalyst is due to the presence of the acid more than ten times larger than that described in the main patent. Example a The The catalyst is prepared as described in Example i, with the difference that that an equivalent amount by weight of technical 40% hydrobromic acid is used finds. The reaction is slower than in Example i, but essentially in the same way and delivers the same product. Example 3 iooo, g copper chloride, 25 cc of technical 37oI hydrochloric acid, 50 g of copper powder and 326 g of ammonium chloride are thoroughly mixed with 50 g of distilled water and placed in a closed Container brought. This mixture is heated with stirring 55 ° C and directs pure acetylene through it, the escaping gases passing through a cooler happen. Water and oily products separate out, the water goes into the catalyst return; while collecting the oily products. The unreacted Acetylene is added to the fresh gas introduced into the mixture. 'If the The speed of the gas circulation is kept slightly above the point -will; at which 8 to 9 l of acetylene react per hour, one obtains after Reduction of the total cupric copper (in a 4 to 8 hour operation) a quantitative one Yield of unsaturated oily products. Um- = the content of hydrochloric acid constant to keep, small amounts of the same must be added at frequent intervals for the purpose of replacing the amounts of chlorine passed over with your - product.

When using organic acids. supposed to be the amount of related -With the catalyst applied, the water used must be large enough to allow for stirring. ensure necessary thin liquid (especially when using solid acids) ; however, it should preferably not be what is necessary to dissolve the entire cupro salt Exceed amount.

When working with liquid acids, there is often no need to add water to become if the thin liquid is sufficient for stirring; and in such a case The amount of water present is only that which is known to be contained in the technical acids.

The change is based on the examples listed below explained, in which organic acids are added to the catalyst.

Example 14. One from 383 parts by weight of acetic acid; 427 parts of pyridine, z: 78 parts of copper chloride and 30 parts of finely divided copper powder The mixture is left to dry for several hours and. then in a lockable Treated apparatus with acetylene. After displacement: all the air becomes the system closed and stirred vigorously while continuously introducing acetylene. The color of the catalyst. changes from yellow to: bright red by changing the temperature gradually increases. The temperature can rise to 5o to 6o ° C without disturbances to cause it, but it is preferable to reduce it to about To hold 250 C. When there is a decrease in the rate of absorption of acetylene a slowdown - the reaction indicates, the introduction is interrupted and the Product removed from the catalyst by means of Destilfatiöii. The 'distillate contains some unconverted acetylene, some pyridine and acetic acid from the catalyst, but consists mainly of monovinylacetylene (boiling point approx. 4 to 8 ° C), divinylacetylene, C8Hg and other non-annular, non-benzene, highly unsaturated Hydrocarbons.

The products present in this distillate can be fractionated separate; first of all acetylene escapes when -man the material on the reflux condenser, which is provided with a brine-cooled dephlegmator treated; if the true steam temperature has reached 5 ° C; can be done using a suitable, slowly working isolated fractionation column between 5 tuid ro ° C an im win essential fraction consisting of monovinylacetylene. After distilling off of the monovinylacetylene, the temperature rises rapidly to 80 °, whereupon a second one Fraction from 8o to 9o ° contains the impure divinylacetylene. contains; the latter can be removed by further fractionation or by washing with water for the purpose the removal of acetic acid and pyridine with subsequent distillation. In order to obtain the higher links, the residue must be washed with water for removal the bulk of the pyridine and acetic acid washed and careful fractionation be subjected in vacuum. The catalyst can be cooled and after replacing the during components lost in the distillation, namely pyridine and acetic acid, can be used again, a cycle that can be repeated as often as desired.

In the above procedure, formic acid can be used in place of acetic acid used in a molecular equivalent amount, a change in the products does not occur as a result of this replacement. Example The one described in: Example 4 The procedure can be carried out using 685 parts of technical 85% lactic acid run in place of acetic acid. Working method and implementation products are in the . essentially the same.

Example 6 The procedure described in Example 4 can be carried out using a catalyst; which is composed of 39o parts of acetic acid, T'78 parts of copper chloride, 3o parts of copper powder, q, ooo parts of pyridine and 3o parts of pyridine hydrochloride. Working method and. Reaction products are essentially the same. BeisPie.l7 The procedure described in Example 4 can be carried out using a catalyst which consists of 1.78 parts of copper chloride, 30 parts of copper powder, 805 parts of diethylaniline and 325 parts of technical 90 ° formic acid. The procedure and reaction products are essentially the same as in Example 4: The conditions described in the preceding examples do not need to be strictly observed. : The composition ratio of the catalyst mass can thus be varied within wide limits. You can also work with air admission or closure. If you are working in individual batches, it is best to conduct the process at below 50 ° C .; in the continuous process, temperatures can go up to zoo ° C, although the preferred range is between 45 or 50 and 60 ° C.

The preferred catalyst to be used, apart from the acid; can be used as an essentially saturated aqueous solution of a cupro salt, finely divided copper and an ammonium or tertiary amine salt will.

The presence of the copper powder is not essential. Its function is simply the presence of all bound copper in cupro form ensure that cupric copper causes undesirable side reactions. Instead of of the Cüpro salt, a mixture of Cupris salt and a reducing agent can occur, however, it is best to have all of the copper salt in reduced form before that you start to work.

Instead of the ammonia or amine salt you can free ammonia or Amine. add as well as any tertiary nitrogenous base, which by means of the Neutralize acid present as a hallmark of this invention and convert it to a salt convict Aasst. For the purpose of this invention represents pyridine. that preferably tertiary amine used (a tertiary amine can be used as an amine compound define where the nitrogen has two or three carbon atoms by three Ties).

It is not necessary that the initially added amine component is a salt of the same acid present in the catalyst or the anion of the copper salt forms. For example, pyridine formate can be used for a catalyst find, which also contains copper bromur and free hydrochloric acid, so that three different ones Anions are present. For the best results it is desirable to that the ammonium or amine salt in a to complete saturation of the liquid phase sufficient amount, the cupro salt in a complete saturation Amount available. However, these conditions are not essential.

If a catalyst is prepared which contains 45 parts of cuprous copper (in the form of 70 parts of copper chloride) and the correct amount of water, copper powder and ammonium chloride, acid can be added to such an extent that not more than 0.09 parts of ionizable hydrogen are present, because there is no free amine in the system. The 0.09 parts of ionizable hydrogen could, for example, be supplied by 8.86 parts of technical 37% hydrochloric acid.

In some cases (Example 3), especially the continuous one Process, small amounts of acid go out of the catalyst with the acetylene polymer lost. When using the hydrochloric acid catalyst, acid losses are: on volatilization and to reduce the formation of small amounts of chlorine-containing products. The ones from the Acid disappeared catalyst must be determined and determined for best results to be constantly replaced: one by means of acetic acid and pyridines, copper chlorurs and Catalyst made from copper is capable of approximately zo to aomal as much acetylene to be converted into higher-boiling polymers than an aqueous ammonium chloride or pyridine catalyst with the same weight of copper.

The method described for carrying out the absorption can also be used vary widely. The acetylene can be in the absorption mixture under pressure introduced and the pressure applied to said mixture for a reasonable time allowed to effect complete absorption and reaction. That The reaction mixture can also be kept at an elevated temperature in order to carry out the process to support the desired reactions.

Monovinylacetylene, one of the end products; was first discovered by W ill stä tt er and W ir th (reports of Deutsche Chem. Ges., Vol. 46, p. 535) by exhaustive methylation of r, 4-tetramethyldiaminobutene-a. Molecular formula ... C4 H4, structural formula ... C H2 = CH - C = - CH, boiling limits ..... 6 ° to ro ° C.

It forms a yellow salt with ammoniacal copper chloride Silver nitrate a white, sparingly soluble salt and with the solutions of the cupro salts numerous complex addition compounds. .

Claims (7)

`PATENT CLAIMS; i, modification of the manufacturing process does not benzene-like unsaturated hydrocarbons of higher molecular weight from acetylene according to patent 588 283, characterized in that the catalyst mixture is a free Acid or a mixture of different cupro salts soluble in the catalyst mixture forming acids with a dissociation constant of at least ro-6 in such Amount is added that the total acid including those acid which arises from dissociation of the cuprous salt in solution; in the catalyst mixture a hydrogen ion concentration of at least pH - 6 results in: 2. Procedure according to Claim i, characterized; that the catalyst mixture is an inorganic one Acid is added in an amount -the ionizable hydrogen in the amount of does not exceed 0; 2 ° f, of the cupro copper present in the system. - 3. Procedure according to claim 2, characterized in that the Kataly satormischüng one or several of the following acids: hydrochloric acid, hydrobromic acid, hydriodic acid, Sulfuric acid, phosphoric acid, can be added. 4. The method according to claim i to 3, characterized in that all of the water of the catalyst mixture or a Part of the same: by an organic acid (or a mixture of organic acids) is replaced. 5. The method according to claim 4, characterized in that the catalyst mixture a carboxylic acid such as acetic acid, chloroacetic acid, formic, citric, tartaric, propionic, Butyric or lactic acid, or one containing one or more such acids Mixture is added. 6. The method according to claim i, characterized in that the aqueous catalyst mixture free copper, copper chloride and one for saturation sufficient - amount of ammonium chloride or pyridine, together with hydrochloric acid, contains. 7. The method according to claim 6, characterized in that one uses a Katälysatorlösung which consists of 7o parts of copper chloride, 27 -: parts of ammonium chloride, 7 parts of finely divided copper, 30 parts of water and 2, z parts of hydrochloric acid. (37 1 / o), the reaction temperature being kept below 50 ° C. B. The method according to claim 6, characterized in that a catalyst mixture is used which consists of 7o parts of copper chloride; 27 parts of ammonium chloride, 7 parts of finely divided copper, 30 parts of water and 2.1 parts of hydrochloric acid (37 ° / o), while keeping the reaction temperature at about 2.5 ° C, the hydrocarbon mixture formed is distilled off and the temperature between -0 and 10 ° C accumulating fraction consisting of monovinylacetylene collects. G. Process according to claim 6, characterized in that acetylene is introduced in an uninterrupted flow in excess of excess acetylene at a temperature between 45 and 100 ° C into a catalyst consisting of copper chloride, a sufficient amount of ammonium chloride and hydrochloric acid to saturate the solution For the purpose of separating the water, the non-reacted acetylene and the reaction products, the gases are passed into a cooler and the separated water and the non-reacted acetylene are returned to the reaction vessel. ok Process according to claim 6, characterized in that at a temperature of 40 to 60 ° C in a catalyst mixture consisting of about 100 g of copper chloride, 25 ccm of 37% hydrochloric acid, 50 g of copper powder, 326 g of ammonium chloride and 450 g of water continuously introduces acetylene into a closed container at a rate of about g 1 per hour, separates the escaping gases into water in a cooler, separates the reaction products and the acetylene that has not reacted, and puts the separated water and the acetylene that has not reacted back into the reaction vessel recycled, keeping the content of hydrochloric acid in the catalyst mixture essentially constant. ii. Process according to Claim 5, characterized in that the acetylene is brought into contact at a temperature of about 25 ° C with an aqueous catalyst mixture consisting of about 383 parts by weight of acetic acid, 427 parts of pyridine, 178 parts of copper chloride and 30 parts of finely divided copper.