Production of Special Isocyanates by Co-Phosgenation

Abstract

The present invention relates to a process for producing isocyanates via phosgenation of the corresponding amines, in particular via gas-phase phosgenation (GPP) or liquid-phase phosgenation (FPP), wherein an amine mixture formed from at least one first amine and at least one second amine different from the first amine is reacted with phosgene to form a reaction mixture, and in particular, for the corresponding isocyanates obtained in the production process, a higher yield and / or good purity (in the form of a reduction in the content of acid chlorine compounds (AC value) and / or the content of hydrolyzable chlorine (HC value)) is achieved. The present invention also relates to products obtainable / obtainable by using the process according to the invention, preferably products directly obtainable / obtainable by using the process according to the invention, and to the use of said products and / or isocyanates or isocyanate mixtures obtainable / obtainable by using the process according to the invention. The present invention further relates to a phosgenation system for carrying out the process according to the invention.

Description

Technical Field

[0001] The present invention relates to a process for producing isocyanates by phosgenation of the corresponding amines, in particular by gas-phase phosgenation (GPP) or liquid-phase phosgenation (LPP), in which an amine mixture formed from at least one first amine and at least one second amine different from the first amine is reacted with phosgene to provide, in particular for the corresponding isocyanates obtained in the production process, a reaction mixture in which a higher yield and / or good purity (in the form of a reduction in the content of acidic chlorine compounds (AC value) and / or the content of hydrolyzable chlorine (HC value)) is achieved. The present invention also relates to products obtainable by or obtained by the process of the present invention, preferably products directly obtainable by or obtained by the process of the present invention, and to the use of said products and / or isocyanates or isocyanate mixtures obtainable by or obtainable by the process of the present invention. The present invention further relates to a phosgenation plant for carrying out the process of the present invention.

Background Art

[0002] Isocyanates, especially diisocyanates, and in some cases low molecular weight triisocyanates, as well as high molecular weight polyaddition products having terminal isocyanate groups obtainable from said compounds, are valuable raw materials for the production of polyurethanes. It is industrially advantageous to produce isocyanates by phosgenation of the parent amines either in the condensation phase (liquid phase phosgenation, hereinafter LPP) or in the gas phase (gas phase phosgenation, hereinafter GPP). The latter is only feasible in the case of amines that can be evaporated without decomposition at the selected pressure. In general, many isocyanates that cannot be produced by LPP or can only be produced in low yields or with insufficient purity have been found to be produced better by GPP. This applies in particular to diisocyanates having sensitive functional groups such as ether bridges in their molecular structure (see EP-A 764633 and the information sources cited therein).

[0003] Some isocyanates containing ether groups can be produced in good yields and high purity by GPP, but this does not apply to all industrially relevant types of this substance class. For example, the acidity or content (hereinafter AC, AC value, AC content) of the acid chloride compound of 1,5 - diisocyanato - 3 - oxapentane (hereinafter OBDI) and the content of hydrolyzable chlorine (hereinafter HC, HC value, HC content) are not low enough to allow trouble - free further processing of this diisocyanate in typical polyurethane applications (see comparative examples). Other examples are (poly) cyclic ether group - containing amines having cyclic ether structural units, such as furan, dihydrofuran, tetrahydrofuran, sorbitol, mannitol and iditol - based (isohexide) sugar derivatives, where it is not important whether the amino group is directly bonded to the (poly) ring or is bonded via additional bridging atoms. The distillative removal of HC - containing impurities is difficult, if not impossible, for many of these compounds, especially for OBDI.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, an object of the present invention was to provide a method for producing isocyanates by phosgenation (gas-phase and / or liquid-phase phosgenation) of the corresponding amines, and a phosgenation plant for carrying out this method. In particular, a further object of the present invention was to convert an "at-risk" amine (hereinafter also referred to as "amine 1" or "primary amine") with respect to phosgenation into the corresponding isocyanate (hereinafter also referred to as "isocyanate 1") in an industrially efficient manner. In particular, high yields and / or good purity should be achieved in the form of a reduction in the content of acid chloride compounds (AC value) and / or hydrolyzable chlorine (HC value) of the corresponding isocyanate obtained in the production process.

Means for Solving the Problems

[0006] This object is achieved by a method for producing isocyanates by phosgenation of the corresponding amines, wherein an amine mixture formed from at least one primary amine and at least one secondary amine different from the primary amine is reacted with phosgene to obtain a reaction mixture, · the primary amine contains at least one ether group, and · the secondary amine is selected from the group consisting of or comprising an aminoalkane having 5 to 15 hydrocarbon atoms and not containing an ether group, or · the first amine contains at least one cyclic ether group, and · the second amine contains at least one acyclic ether group and does not contain a cyclic ether group characterized by any one of these.

[0007] The present invention also relates to the use of an amine mixture formed from at least one first amine and at least one second amine different from the first amine in a process for producing a corresponding isocyanate by phosgenation according to the method of the present invention, in order to reduce the content of the acidic chlorine compound and / or the content of hydrolyzable chlorine of the corresponding isocyanate obtained in the production process.

[0008] The present invention further relates to a product obtainable or obtained by the method of the present invention, preferably directly obtainable or obtained by the method of the present invention.

[0009] Furthermore, the present invention relates to the use of the product of the present invention and / or an isocyanate or isocyanate mixture obtainable or obtained by the method of the present invention as a component for the production of polyurethanes, in particular polyurethane foams, polyurethane coatings, and polyurethane adhesives, and polyurethane adhesives, pharmaceuticals, in particular active substances, and auxiliaries, in particular auxiliaries for wet strength finishing of paper and other cellulose products, emulsifiers and thickeners.

[0010] The present invention further relates to a phosgenation plant for carrying out the method of the present invention, comprising: (a) at least one phosgene device for continuously supplying phosgene, optionally in combination with an inert substance; (b) optionally, an inert substance device for supplying an inert substance; (c) at least one amine device for continuously supplying an amine mixture, optionally in combination with an inert substance; and (d) a phosgenation reactor for mixing phosgene, an amine mixture, and optionally an inert substance, and reacting the amine mixture with phosgene comprises or consists of wherein the amine apparatus comprises a first storage container for the first amine, a second storage container for the second amine, a metering device for independently and variably adjusting the mass fractions of the first amine and the second amine, and optionally a mixing device for mixing the first amine and the second amine to form an amine mixture relates to a phosgenation plant, characterized by the above

[0011] Surprisingly, it has been found that a mixture of amine 1 (“the first amine”) and an amine that has no problem with phosgenation (hereinafter also referred to as “amine 2” or “the second amine”) can be converted to the corresponding mixture of isocyanate 1 and isocyanate 2 much more smoothly than in the case of phosgenation of amine 1 alone. This method of the present invention is hereinafter also referred to as co-phosgenation or simply CoPg for short. The resulting isocyanate 2 is at least equivalent in terms of yield and quality (especially the content of acidic chlorine compounds (AC value) and / or the content of hydrolyzable chlorine compounds (HC value)) to that resulting from phosgenation of amine 2 itself. However, what is particularly surprising is that the diisocyanate 2 obtainable from amine 2 by the method of the present invention is often produced with a significantly higher purity than when phosgenation is carried out alone under other equivalent conditions. Further details are given in the exemplary embodiments. Furthermore, it has been found that amines having open-chain ether groups have relatively few problems with phosgenation compared to amines having cyclic ether groups. Here too, in the method of the present invention, it has been found that an amine mixture formed from an amine having at least one cyclic ether group and an amine having exclusively open-chain ether groups shows the same improvement in terms of yield and quality (especially in terms of the content of acidic chlorine compounds (AC value) and / or the content of hydrolyzable chlorine compounds (HC value)). With respect to the present invention, the content of acidic chlorine compounds and the content of hydrolyzable chlorine were determined in accordance with the ISO 15028:2014 standard.

[0012] The phosgenation of isomer mixtures, such as the industrially established phosgenation of 2,4- and 2,6-diaminotoluene to TDI, and the phosgenation of mixtures of isomers and homologues of amines resulting from aniline-formaldehyde condensation (MDA -> MDI) are well-known examples of the phosgenation of mixtures of different individual chemical substances, but the rationale for this approach is only that the formation of the parent amines results in a mixture of isomers and / or homologues that it is not economical or technically unrealistic to separate into their individual components. The options used here are not to perform the corresponding separation of the amine mixture beforehand, but rather to isolate from the isocyanate mixture substances that can be more readily obtained in pure form by crystallization (2,4-TDI, the so-called "T100") or distillation (monomeric MDI, e.g., 4,4'-bis(isocyanatophenyl)methane, 2,4'-bis(isocyanatophenyl)methane, and 2,2'-bis(isocyanatophenyl)methane, and any mixture of the three individual compounds, hereinafter 2-ring MDI). In the aliphatic series, IPDA and cyclo-hydrogenated 2-ring MDA (established acronym: H12MDA, PACM) are examples of mixtures of diamine positions and / or stereoisomers that necessarily occur, and after phosgenation, they are converted into the corresponding isomer mixtures of diisocyanates IPDI and / or H 12 -MDI, respectively. In the latter case, the separation of the pure trans-trans-4,4' isomer is also possible by crystallization.

[0013] For the purpose of phosgenation, a mixture in which two (or more) chemically completely different amines from completely different production processes are intentionally provided has so far been described only in DE2249459. In this case, in the present invention, in order to avoid the necessity of constructing an expensive separate plant for aliphatic isocyanates which is technically required in only quite small amounts, it is essential to use aromatic amine 2 (in the meaning of the present application) as the "base amine" for producing aliphatic isocyanates from the corresponding amines. The solution to the above technical problem is not provided by DE2249459, and as can be seen from the HC content (0.1% or more) of the isocyanates described in the examples of DE2249459, it cannot be solved according to its teachings. As shown in Example 1 of this specification, the method of DE2249459 also cannot overcome the problems in the production of the special isocyanates related to the present application.

[0014] Also, considering on the one hand the mean free path lengths between different molecules in the gas phase and on the other hand the often high dilution in the liquid phase, it is also surprising that the CoPg of the first amine and the second amine (amine 1 and 2) has some beneficial effect on the overall operation in addition to the obvious economic advantages explained in DE2249459. This is because, for example, a second plant is not required for the production of special isocyanates in tonnages less than those usually used in MDI production.

[0015] Also, considering on the one hand the mean free path lengths between different molecules in the gas phase and on the other hand the often high dilution in the liquid phase, for example, a second plant is not required for the production of special isocyanates in tonnages less than those usually used in MDI production. Therefore, it is also surprising that the CoPg of the first amine and the second amine (amine 1 and 2) has some beneficial effect on the overall operation in addition to the obvious economic advantages explained in DE2249459.

[0016] The present invention relates to a process for producing isocyanates by phosgenation of the corresponding amines, comprising reacting an amine mixture formed from at least one first amine and at least one second amine different from the first amine with phosgene to obtain a reaction mixture, · the first amine contains at least one ether group, and · the second amine is selected from the group consisting of or comprising an aminoalkane having 5 to 15 hydrocarbon atoms and not containing an ether group, or · the first amine contains at least one cyclic ether group, and · the second amine contains at least one open-chain ether group and does not contain a cyclic ether group characterized by any one of these.

[0017] The phosgenation is preferably gas-phase phosgenation (GPP) or liquid-phase phosgenation (LPP). The mixing ratio of the first and second amines (amine 1 and 2) can vary within a wide range in the process of the present invention (20:1 to 1:20). Preferably, the mixing ratio of the first amine to the second amine is 1:9 to 9:1, more preferably 2:8 to 8:2. It is clear that when the proportion of amine 1 in the amine mixture is high, the yield of the resulting isocyanate 1 will be high. However, it is also preferred that the proportion of amine 1 that receives CoPg as a mixture with amine 2 does not become too high, especially for the production of pure isocyanate 1. In gas-phase phosgenation, it is also possible to change the ratio of amine 1 to amine 2 (first amine to second amine) during the reaction process, that is, only amine 2 is metered in at the starting stage, and finally only amine 1 is metered in when a stable operating state (steady state) is achieved. In this particular embodiment of the method, especially at the start of gas-phase phosgenation, it is often necessary to pass through a critical phase that is better controlled by amine 2 than by amine 1, and the fact that the experiment is aborted when only amine 1 is metered in at the starting stage is utilized.

[0018] In the selection of amines 1 and 2, care can be taken to ensure that the resulting isocyanates 1 and 2 are readily separable from each other, for example, by distillation, extraction, or crystallization. However, it is also possible to use a mixture of isocyanates 1 and 2, usually after distillative removal of coloring and high-boiling impurities, in the form of the mixture that results from the process of the present invention.

[0019] This approach is clearly excluded in DE2249459 (see DE2249459, page 4, last paragraph and claims 1 to 3), as it is emphasized here that it is essential for the present invention that the (two) isocyanates are separable at the end of the process.

[0020] In particular, the first amine containing at least one ether group, the first amine containing at least one cyclic ether group, the second amine comprising or consisting of an aminoalkane having 5 to 15 hydrocarbon atoms, and / or the second amine containing at least one open-chain ether group and no cyclic ether group is a diamine.

[0021] The first amine containing at least one ether group preferably has the general formula X-(-R 1 -NH m ) n (wherein - X is H, NH m or C(R 2 ) p ; - R 1 is an optionally substituted and / or heteroatom-containing aliphatic, (cyclo)aliphatic or aromatic radical, preferably having up to 10 carbon atoms, where R 1 contains at least one ether group, - R 2 is H or an optionally substituted and / or heteroatom-containing aliphatic, (cyclo)aliphatic or aromatic radical, preferably having up to 10 carbon atoms, - m is 1 or 2, - n is 1, 2, or 3, and - p is 1, 2, or 3) includes the structure of

[0022] In a preferred embodiment, the first amine containing at least one ether group is (tetrahydrofuran-2,5-diyl)(TEFUDA), 3,6-diaminohexahydrofuro[3,2-b]furan (e.g., IDDA and / or ISODA), 3,6-bis(aminomethyl)hexahydrofuro[3,2-b]furan, furan-2,5-diyldimethanamine, (methane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (methane-2,2-diylbis(furan-5,2-diyl))dimethanamine, (propane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (propane-2,2-diylbis(furan-5,2-diyl))dimethanamine; di(aminoethyl)ether, in particular, 2,2'-oxybis(ethane-1-amine), 1,1'-oxybis(propane-2-amine), 2-(2-aminoethoxy)propane-1-amine, 2,2'-oxybis(propane-1-amine), and 2-(2-aminopropoxy)propane-1-amine; di(aminopropyl)ether or a mixture thereof, or is selected from any group thereof. The first amine containing at least one cyclic ether group preferably includes (tetrahydrofuran-2,5-diyl)dimethanamine (TEFUDA), 3,6-diaminohexahydrofuro[3,2-b] (e.g., IDDA and / or ISODA), 3,6-bis(aminomethyl)hexahydrofuro[3,2-b]furan, furan-2,5-diyldimethanamine, (methane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (methane-2,2-diylbis(furan-5,2-diyl))dimethanamine, (propane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (propane-2,2-diylbis(furan-5,2-diyl))dimethanamine or a mixture thereof, or is selected from any group thereof.

[0023] More preferably, the second amine containing or consisting of an aminoalkane having 5 to 15 hydrocarbons is 1,5-diaminopentane; 1,6-diaminohexane; 1-amino-3,5,5-trimethyl-5-aminomethylcyclohexane; amino-[(aminocyclohexyl)methyl]cyclohexane, especially 4,4'-methylenebis(cyclohexane-1-amine), 2-((4-aminocyclohexyl)methyl)cyclohexane-1-amine, and 2,2'-methylenebis(cyclohexane-1-amine); 1,3-bis(aminomethyl)cyclohexane; 1,4-bis(aminomethyl)cyclohexane; diaminocyclohexane, especially cyclohexane-1,2-diamine, cyclohexane-1,3-diamine, and cyclohexane-1,4-diamine; methyldiaminocyclohexane, especially 4-methylcyclohexane-1,3-diamine and 2-methylcyclohexane-1,3-diamine; 4,4'-methylenebis(2-methylcyclohexane-1-amine); or a mixture thereof, or is selected from the group consisting of them. However, several other amines may also be suitable as "amine 2", which can be easily determined by simple preliminary tests.

[0024] The secondary amine containing at least one open-chain ether group and no cyclic ether group is preferably di(aminoethyl) ether, di(aminopropyl) ether, 1,8-diamino-1,5,8-trimethyl-3,6-dioxaoctane, 1,11-diamino-1,5,8,11-tetramethylundecane, 1,8-diamino-3,6-dioxaoctane, 1,10-diamino-4,7-dioxadecane, 1,12-diamino-4,9-dioxadodecane, 1,14-diamino-3,10-dioxatetradecane, 1,13-diamino-4,7,10-trioxatridecane, 1,7-diamino-2,6-dioxo-4-aminomethoxy-heptane, 1-amino-2-oxa-3,3-bis(aminomethoxy)hexane, 1,9-diamino-3,7-dioxo-5-(1-amino-2-ethoxy)-nonane, 1-amino-3-oxa-4,4-bis(1-amino-2-ethoxy)heptane, 1,11-diamino-4,8-dioxo-6-(1-amino-5-oxabutyl)undecane, 1-amino-4-oxa-5,5-bis(1-amino-5-oxabutyl)octane or a mixture thereof, or is selected from any group thereof.

[0025] The limiting factors regarding the usability of the monoamines and polyamines containing ether groups in the CoPg of the present invention in certain embodiments of the gas-phase phosgenation are not seen in the number of (primary) amino groups nor in the number of ether bonds, but are determined only by the volatility under the applied pressure. Thus, especially in the case of high-boiling compounds, it may be advantageous to introduce them into the gas-phase phosgenation in the form of an azeotropic mixture with other substances or to use a carrier gas for supplying the amine mixture to the reaction space. In this case, amine 2 can have a promoting effect.

[0026] Furthermore, based on the total weight of the amine mixture, · the mass fraction of the first amine is 5.0 wt% to 95.0 wt%, preferably 10.0 wt% to 80.0 wt%, and · The mass fraction of the secondary amine is 95.0 wt% to 5.0 wt%, preferably 90.0 wt% to 20.0 wt%, more preferably 80.0 wt% to 20.0 wt%. This is preferred.

[0027] The molar ratio of phosgene to the amino groups of the amines in the amine mixture is preferably ≥1:1 to ≤5:1, preferably >1:1 to ≤3:1, more preferably >1:1 to ≤2:1.

[0028] Preferably, an inert substance is further used in the reaction, and the inert substance is · An inert gas, especially nitrogen, argon or a mixture thereof; · An inert solvent, especially an aromatic hydrocarbon, preferably chlorobenzene, o-dichlorobenzene, toluene, xylene or a mixture thereof; · Or a mixture of the aforementioned inert gas and inert solvent is included or selected from the group consisting of these.

[0029] Preferably, · The temperature of the condensation reaction is initially between -40°C and the boiling point of the solvent or the lowest-boiling feedstock used at the pressure established in the reaction, and · The temperature of the gas-phase phosgenation is between the boiling point of the reactant having the highest boiling point T1 at the system pressure and 600°C, preferably between T1 and 550°C, more preferably between T1 and 500°C.

[0030] The isocyanate corresponding to the first amine and / or the isocyanate corresponding to the second amine is also preferably separated from the reaction mixture, and the separation is preferably carried out by distillation, especially thin-film distillation, extraction, crystallization, recrystallization or a combination thereof, and each isocyanate is obtained separately or as an isocyanate mixture. It is more preferable to separate the isocyanate corresponding to the first amine and the isocyanate corresponding to the second amine from the reaction mixture, and the separation is preferably carried out by distillation, especially thin-film distillation, extraction, crystallization, recrystallization or a combination thereof, and each isocyanate is obtained separately or as an isocyanate mixture. The content of acidic chlorine compounds (also referred to as AC value, AC content or acidity) in the separated isocyanate or isocyanate mixture is determined according to the ISO 15028:2014 standard and is 1 to 100 ppm, preferably 2 to 80 ppm, more preferably 5 to 50 ppm. The content of hydrolyzable chlorine (also referred to as HC value or HC content) in the separated isocyanate or isocyanate mixture is determined according to the ISO 15028:2014 standard and is preferably 1 to 500 ppm, preferably 5 to 100 ppm.

[0031] In a preferred embodiment, the present invention relates to a process for the production of isocyanates by phosgenation of the corresponding amines, wherein an amine mixture formed from at least one first amine and at least one second amine different from the first amine is reacted with phosgene to obtain a reaction mixture, · the first amine contains at least one ether group, and · the second amine is selected from the group consisting of or comprising an aminoalkane having 5 to 15 hydrocarbon atoms and not containing an ether group, or · the first amine contains at least one cyclic ether group, and · the second amine contains at least one open-chain ether group and does not contain a cyclic ether group characterized by any of the above, Here, the first amine containing at least one ether group is selected from the group consisting of or including (tetrahydrofuran-2,5-diyl)dimethanamine, 3,6-diaminohexahydrofuro[3,2-b]furan, 3,6-bis(aminomethyl)hexahydrofuro[3,2-b]furan, furan-2,5-diyl dimethanamine, (methane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (methane-2,2-diylbis(furan-5,2-diyl))dimethanamine, (propane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (propane-2,2-diylbis(furan-5,2-diyl))dimethanamine; di(aminoethyl)ether, especially 2,2'-oxybis(ethane-1-amine), 1,1'-oxybis(propane-2-amine), 2-(2-aminoethoxy)propane-1-amine, 2,2'-oxybis(propane-1-amine) and 2-(2-aminopropoxy)propane-1-amine; di(aminopropyl)ether or a mixture thereof, and / or the first amine containing at least one cyclic ether group is selected from the group consisting of or including (tetrahydrofuran-2,5-diyl)dimethanamine, 3,6-diaminohexahydrofuro[3,2-b]furan, 3,6-bis(aminomethyl)hexahydrofuro[3,2-b]furan, furan-2,5-diyl dimethanamine, (methane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (methane-2,2-diylbis(furan-5,2-diyl))dimethanamine, (propane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (propane-2,2-diylbis(furan-5,2-diyl))dimethanamine or a mixture thereof, and the second amine containing or consisting of an aminoalkane having 5 to 15 hydrocarbon atoms is selected from the group consisting of or containing 1,5-diaminopentane; 1,6-diaminohexane; 1-amino-3,5,5-trimethyl-5-aminomethylcyclohexane; amino-[(aminocyclohexyl)methyl]cyclohexane, especially 4,4'-methylenebis(cyclohexane-1-amine), 2-((4-aminocyclohexyl)methyl)cyclohexane-1-amine, and 2,2'-methylenebis(cyclohexane-1-amine); 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane; diaminocyclohexane, especially cyclohexane-1,2-diamine, cyclohexane-1,3-diamine, and cyclohexane-1,4-diamine; methyldiaminocyclohexane, especially 4-methylcyclohexane-1,3-diamine and 2-methylcyclohexane-1,3-diamine, 4,4'-methylenebis(2-methylcyclohexane-1-amine); or mixtures thereof, and the second amine containing at least one open-chain ether group and no cyclic ether group is selected from the group consisting of or containing di(aminoethyl)ether, di(aminopropyl)ether, 1,8-diamino-1,5,8-trimethyl-3,6-dioxaoctane, 1,11-diamino-1,5,8,11-tetramethylundecane, 1,8-diamino-3,6-dioxaoctane, 1,10-diamino-4,7-dioxadecane, 1,12-diamino-4,9-dioxadodecane, 1,14-diamino-3,10-dioxatetradecane, 1,13-diamino-4,7,10-trioxatridecane, 1,7-diamino-2,6-dioxo-4-aminomethoxy-heptane, 1-amino-2-oxa-3,3-bis(aminomethoxy)hexane, 1,9-diamino-3,7-dioxo-5-(1-amino-2-ethoxy)-nonane, 1-amino-3-oxa-4,4-bis(1-amino-2-ethoxy)heptane, 1,11-diamino-4,8-dioxo-6-(1-amino-5-oxabutyl)undecane, 1-amino-4-oxa-5,5-bis(1-amino-5-oxabutyl)octane or mixtures thereof Relates to a method. This embodiment can be freely combined with other embodiments unless it is clear that it is contrary to the present invention.

[0032] The present invention further relates to the use of an amine mixture formed from at least one first amine and at least one second amine different from the first amine in a method for producing a corresponding isocyanate by phosgenation according to any one of claims 1 to 13, for reducing the content of the corresponding acid chloride compound and / or the content of hydrolyzable chlorine in the corresponding isocyanate obtained in the production process.

[0033] The present invention further provides a product that can be obtained or is obtained by the method of the present invention, preferably a product that can be directly obtained or is obtained by the method of the present invention.

[0034] The present invention also provides the use of the product of the present invention and / or an isocyanate or isocyanate mixture that can be obtained or can be obtained by the method of the present invention as a component for the production of pharmaceuticals, particularly active substances, and auxiliaries, particularly auxiliaries for wet strength finishing of paper and other cellulose products, emulsifiers, and thickeners in polyurethanes, particularly polyurethane foams, polyurethane coatings, and polyurethane adhesives.

[0035] The GPP process of the present invention is, in its main features, carried out by a prior art method known per se, for example according to the teachings of EP0570799 or EP0676392 and variations of the processes cited therein. For this purpose, the co-reactants are introduced into a suitable reactor at or near the boiling point of the starting amine(s) and mixed and reacted with each other. Depending on the pressure selected, this temperature is between 100 and 600 °C, preferably between 150 and 500 °C. This process is carried out in a pressure range of 10 mbar to 5 bar, preferably 200 mbar to 3 bar. The reaction components in the gas-phase phosgenation can be fed with or without the use of an inert additive such as a carrier gas for the phosgenation reaction. Suitable carrier gases include nitrogen, argon or other inert gases, and the vapors of technically available solvents such as chlorobenzene, dichlorobenzene, xylene, chloronaphthalene, decahydronaphthalene.

[0036] The isocyanate mixture of the present invention is then obtained by cooling the gas stream to a temperature above the decomposition temperature of the corresponding carbamoyl chloride intermediate. In a preferred embodiment, the isocyanate corresponding to the first amine and / or the isocyanate corresponding to the second amine is then separated from the reaction mixture, and the separation is preferably carried out by distillation, in particular thin-film distillation, extraction, crystallization, recrystallization or combinations thereof, and the corresponding isocyanates are obtained separately or as an isocyanate mixture. Particularly preferably, the isocyanate corresponding to the first amine and the isocyanate corresponding to the second amine are separated from the reaction mixture. After separation by distillation, it is also preferable to carry out recrystallization if necessary.

[0037] The products of the process according to the invention are valuable starting materials for producing oligomeric isocyanate-modified products such as polyurethanes, adhesives, coating agents, uretdione-, isocyanurate-, carbodiimide-, biuret-, urethane- and allophanate-containing polyisocyanates, auxiliaries such as those used for the wet strength finishing of paper and other cellulose products, emulsifiers, thickeners, active substances, and starting materials for the production and / or formulation of pharmaceuticals.

[0038] Finally, the invention further relates to a phosgenation plant for carrying out the process according to the invention, comprising: (a) at least one phosgene device for continuously supplying phosgene, optionally in combination with an inert substance; (b) optionally, an inert substance device for supplying an inert substance; (c) at least one amine device for continuously supplying an amine mixture, optionally in combination with an inert substance; and (d) a phosgenation reactor for mixing phosgene, the amine mixture, and optionally an inert substance and reacting the amine mixture with phosgene, comprising or consisting of these, wherein the amine device comprises a first storage container for a first amine, a second storage container for a second amine, a metering device for independently and variably adjusting the mass fraction of the first amine and the second amine, and optionally a mixing device for mixing the first amine and the second amine to form an amine mixture. The invention relates to a phosgenation plant characterized by this.

[0039] The phosgene flow device, any inert substance flow device, amine flow device, and phosgenation reactor can independently comprise further devices useful for the operation of the phosgenation plant, such as storage containers for starting materials, heat exchangers for controlling or optionally evaporating the temperature of the starting materials, and devices for treating the reaction mixture at the completion of the reaction between the amine and phosgene.

[0040] The metering device may be, for example, a metering pump or a control valve. Any mixing device may be, for example, a T-piece in a pipeline, a mixing chamber, a static mixer, or a pump, in particular a mixing pump, or a stirring vessel. However, it is also possible to mix the amine stream from the metering device in an evaporator. The evaporator is used especially in the case of liquid amines.

[0041] The amine stream device preferably comprises at least one flange connection provided for the accommodation of a blank in at least one of the amine conducting pipelines. This makes it possible to reliably prevent the flow of amine through the corresponding conduit by means of the blank or to reliably cut off the corresponding amine conduit.

[0042] The phosgene stream device, any inert substance stream device, and the amine stream device are each connected to the phosgenation reactor via at least one inlet. The connection of the inlet to the phosgenation reactor may be, for example, via a simple pipeline, a flange connection, a smooth jet nozzle, an annular gap nozzle or a mixing element. The annular gap nozzle may here comprise two or more channels, preferably two in a coaxial arrangement, for the amine stream and the phosgene stream or the inert gas stream, where the amine stream and the phosgene stream do not merge until they enter the phosgenation reactor. Alternatively, especially in industrial scale applications, the amine is added to the phosgenation reactor via an inlet pipe which has a central nozzle at its end and is held in place by a cover and any holder / rectifier, as a result of which an annular space is formed around the inlet pipe in the reactor, while the phosgene enters the annular space via a separate inlet and then reaches the phosgenation reactor via the rectifier (see also EP1362847 A2). The phosgenation reactor has a mixing zone where the flows first merge and a reaction zone where the flows react further. The mixing zone and the reaction zone are preferably in one device. Furthermore, the phosgenation reactor is preferably essentially upright, which is preferably connected at the upper end to the phosgene stream device and the amine stream device.

[0043] The phosgenation plant also preferably comprises at least one quench for cooling and at least partially condensing the reaction mixture, which is preferably connected to the phosgenation reactor at the lower end, where the quench is designed in particular to introduce chlorobenzene, o-dichlorobenzene, and / or at least one isocyanate produced in the phosgenation plant. In particular, the quench has a dedicated collection vessel, where the collection vessel is preferably incorporated into the quench or connected separately to the quench.

[0044] Preferably, the amine device, any separate inert substance device and / or the phosgene device comprises a heat exchanger for heating the amine mixture, phosgene and / or any inert substance.

[0045] Embodiment: The present invention particularly relates to the following embodiments: In a first embodiment, the present invention is a method for producing an isocyanate by phosgenation of a corresponding amine, wherein an amine mixture formed from at least one first amine and at least one second amine different from the first amine is reacted with phosgene to obtain a reaction mixture, · The first amine contains at least one ether group, and · The second amine is selected from the group consisting of or comprising an aminoalkane having 5 to 15 hydrocarbon atoms and not containing an ether group, Or · The first amine contains at least one cyclic ether group, and · The second amine contains at least one open-chain ether group and does not contain a cyclic ether group relates to a method characterized by any of the above.

[0046] In a second embodiment, the first amine containing at least one ether group has the general formula X-(-R 1 -NH m ) n (wherein - X is H, NHm or C(R 2 ) p and is - R 1 is an optionally substituted and / or heteroatom-containing aliphatic, (cyclo)aliphatic or aromatic radical, preferably having up to 10 carbon atoms, where R 1 contains at least one ether group, - R 2 is H or an optionally substituted and / or heteroatom-containing aliphatic, (cyclo)aliphatic or aromatic radical, preferably having up to 10 carbon atoms, - m is 1 or 2, - n is 1, 2, or 3, and - p is 1, 2 or 3) characterized by including the structure of, relating to the method according to Embodiment 1.

[0047] In a third embodiment, the present invention relates to the method according to Embodiment 1 or 2, characterized in that a first amine containing at least one ether group, a first amine containing at least one cyclic ether group, an aminoalkane having 5 to 15 hydrocarbon atoms, or a second amine comprising or consisting of the same, and / or a second amine containing at least one open-chain ether group and no cyclic ether group is a diamine.

[0048] In a fourth embodiment, the present invention provides that the first amine containing at least one ether group is selected from the group consisting of or including (tetrahydrofuran-2,5-diyl)dimethanamine (TEFUDA), 3,6-diaminohexahydrofuro[3,2-b]furan (e.g., IDDA and / or ISODA), 3,6-bis(aminomethyl)hexahydrofuro[3,2-b]furan, furan-2,5-diyl dimethanamine, (methane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (methane-2,2-diylbis(furan-5,2-diyl))dimethanamine, (propane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (propane-2,2-diylbis(furan-5,2-diyl))dimethanamine; di(aminoethyl)ether, particularly 2,2'-oxybis(ethane-1-amine), 1,1'-oxybis(propane-2-amine), 2-(2-aminoethoxy)propane-1-amine, 2,2'-oxybis(propane-1-amine) and 2-(2-aminopropoxy)propane-1-amine; di(aminopropyl)ether or a mixture thereof, and / or the first amine containing at least one cyclic ether group is preferably selected from the group consisting of or including (tetrahydrofuran-2,5-diyl)dimethanamine, 3,6-diaminohexahydrofuro[3,2-b]furan (e.g., IDDA and / or ISODA), 3,6-bis(aminomethyl)hexahydrofuro[3,2-b]furan, furan-2,5-diyl dimethanamine, (methane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (methane-2,2-diylbis(furan-5,2-diyl))dimethanamine, (propane-2,2-diylbis(tetrahydrofuran-5,2-diyl))dimethanamine, (propane-2,2-diylbis(furan-5,2-diyl))dimethanamine or a mixture thereof, relating to the method according to any of the preceding embodiments.

[0049] In a fifth embodiment, the present invention relates to a method according to any of the preceding embodiments, characterized in that the second amine comprises or consists of an aminoalkane having 5 to 15 hydrocarbon atoms and is 1,5-diaminopentane; 1,6-diaminohexane; 1-amino-3,5,5-trimethyl-5-aminomethylcyclohexane; amino-[(aminocyclohexyl)methyl]cyclohexane, in particular 4,4'-methylenebis(cyclohexane-1-amine), 2-((4-aminocyclohexyl)methyl)cyclohexane-1-amine, and 2,2'-methylenebis(cyclohexane-1-amine); 1,3-bis(aminomethyl)cyclohexane; 1,4-bis(aminomethyl)cyclohexane; diaminocyclohexane, in particular cyclohexane-1,2-diamine, cyclohexane-1,3-diamine, and cyclohexane-1,4-diamine; methyldiaminocyclohexane, in particular 4-methylcyclohexane-1,3-diamine and 2-methylcyclohexane-1,3-diamine; 4,4'-methylenebis(2-methylcyclohexane-1-amine); or a mixture thereof, or consists of a group selected therefrom.

[0050] In the sixth embodiment, the present invention relates to a method according to any of the preceding embodiments, characterized in that the secondary amine containing at least one open-chain ether group and no cyclic ether group is selected from the group consisting of di(aminoethyl)ether, di(aminopropyl)ether, 1,8-diamino-1,5,8-trimethyl-3,6-dioxaoctane, 1,11-diamino-1,5,8,11-tetramethylundecane, 1,8-diamino-3,6-dioxaoctane, 1,10-diamino-4,7-dioxadecane, 1,12-diamino-4,9-dioxadodecane, 1,14-diamino-3,10-dioxatetradecane, 1,13-diamino-4,7,10-trioxatridecane, 1,7-diamino-2,6-dioxo-4-aminomethoxy-heptane, 1-amino-2-oxa-3,3-bis(aminomethoxy)hexane, 1,9-diamino-3,7-dioxo-5-(1-amino-2-ethoxy)-nonane, 1-amino-3-oxa-4,4-bis(1-amino-2-ethoxy)heptane, 1,11-diamino-4,8-dioxo-6-(1-amino-5-oxabutyl)undecane, 1-amino-4-oxa-5,5-bis(1-amino-5-oxabutyl)octane or mixtures thereof, or consisting of them.

[0051] In the seventh embodiment, the present invention relates to a method according to any of the preceding embodiments, characterized in that, based on the total weight of the amine mixture, · the mass fraction of the primary amine is 5.0 wt% to 95.0 wt%, preferably 10.0 wt% to 80.0 wt%, and · the mass fraction of the secondary amine is 95.0 to 5.0 wt%, preferably 90.0 wt% to 20.0 wt%, more preferably 80.0 wt% to 20.0 wt%.

[0052] In the eighth embodiment, the present invention relates to a method according to any of the preceding embodiments, characterized in that the molar ratio of phosgene to the amino groups of the amines in the amine mixture is ≧1:1 to ≦5:1, preferably >1:1 to ≦3:1.

[0053] In the ninth embodiment, the present invention relates to a method according to any of the preceding embodiments, characterized in that an inert substance is used in the reaction and the inert substance is · an inert gas, in particular nitrogen, argon or a mixture thereof, · an inert solvent, in particular an aromatic hydrocarbon, preferably chlorobenzene, o-dichlorobenzene, toluene, xylene or a mixture thereof, · or a mixture of the aforementioned inert gas and inert solvent and is selected from the group consisting of or comprising the same.

[0054] In the tenth embodiment, the present invention relates to a method according to any of the preceding embodiments, characterized in that · the temperature in the condensation reaction is initially between -40 °C and the boiling point of the solvent or the lowest boiling feedstock used at the pressure established in the reaction, and · the temperature in the gas phase phosgenation is between the boiling point of the reactant having the highest boiling point T1 at the system pressure and 600 °C, preferably between T1 and 550 °C, more preferably between T1 and 500 °C and is selected from the group consisting of or comprising the same.

[0055] In the eleventh embodiment, the present invention relates to a method according to any of the preceding embodiments, characterized in that the isocyanate corresponding to the primary amine and / or the isocyanate corresponding to the secondary amine is separated from the reaction mixture, and the separation is preferably carried out by distillation, in particular thin film distillation, extraction, crystallization, recrystallization or a combination thereof, and the corresponding isocyanate is obtained separately or as an isocyanate mixture and is selected from the group consisting of or comprising the same.

[0056] In the 12th embodiment, the present invention is characterized in that the isocyanate corresponding to the first amine and / or the isocyanate corresponding to the second amine is separated from the reaction mixture, and the separation is preferably carried out by distillation, particularly thin-film distillation, extraction, crystallization, recrystallization or a combination thereof, and the corresponding isocyanate is obtained as an isocyanate mixture, and relates to the method according to any one of Embodiments 1 to 10.

[0057] In the 13th embodiment, the present invention is characterized in that the content of the acidic chlorine compound in the separated isocyanate or isocyanate mixture is determined according to the ISO 15028:2014 standard and is 1 to 100 ppm, preferably 2 to 80 ppm, more preferably 5 to 50 ppm, and relates to the method according to Embodiment 11 or 12.

[0058] In the 14th embodiment, the present invention is characterized in that the content of hydrolyzable chlorine in the separated isocyanate or isocyanate mixture is determined according to the ISO 15028:2014 standard and is 1 to 500 ppm, preferably 5 to 100 ppm, and relates to the method according to any one of Embodiments 11 to 13.

[0059] In the 15th embodiment, the present invention relates to the use of an amine mixture formed from a first amine and at least one second amine different from the first amine in a method for producing a corresponding isocyanate by phosgenation according to the method according to any one of Embodiments 1 to 14 for reducing the content of the acidic chlorine compound and / or the content of hydrolyzable chlorine in the corresponding isocyanate obtained in the production process.

[0060] In the 16th embodiment, the present invention relates to a product that can be obtained or is obtained by the method according to any one of Embodiments 1 to 13, preferably any one of Embodiments 10 or 12 to 14, or a product that can be directly obtained or is obtained by the method according to any one of Embodiments 1 to 13, preferably any one of Embodiments 10 or 12 to 14.

[0061] In the 17th embodiment, the present invention relates to the use of a product according to embodiment 16 and / or an isocyanate or isocyanate mixture obtainable or obtainable by the method according to any of embodiments 11 to 14, preferably any of embodiments 10 or 12 to 14, as a component for the production of pharmaceuticals, in particular active substances, and auxiliaries, in particular auxiliaries for wet strength finishing of paper and other cellulose products, emulsifiers, and thickeners, in polyurethanes, in particular polyurethane foams, polyurethane coatings, and polyurethane adhesives.

[0062] In the 18th embodiment, the present invention is a phosgenation plant for carrying out the method according to embodiments 1 to 14, (a) at least one phosgene device for continuously supplying phosgene, optionally in combination with an inert substance, (b) optionally, an inert substance device for supplying an inert substance, (c) at least one amine device for continuously supplying an amine mixture, optionally in combination with an inert substance, and (d) a phosgenation reactor for mixing phosgene and an amine mixture, optionally with an inert substance, and reacting the amine mixture with phosgene comprising or consisting of, The amine device comprises a first storage container for the first amine, a second storage container for the second amine, a metering device for independently and variably adjusting the mass fraction of the first amine and the second amine, and optionally, a mixing device for mixing the first amine and the second amine to form an amine mixture. The present invention relates to a phosgenation plant.

[0063] In the 19th embodiment, the present invention relates to the device according to embodiment 18, characterized in that the amine device, any separate inert substance device, and / or phosgene device comprises a heat exchanger for heating the amine mixture, phosgene, and / or any inert substance.

Examples

[0064] The following examples are intended to illustrate some of the methods of the present invention and the products of the methods of the present invention, more specifically, without intending to limit the present invention, and all percentages are weight percentages unless otherwise specified.

[0065] 1 The molar percentages were determined by 1H-NMR spectroscopy. The measurements were carried out in dry C6D6 samples at about 5% ( 1 1H NMR) or about 50% ( 13 13C NMR), 400 or 700 MHz ( 1 1H NMR) or 100 or 176 MHz ( 13 13C NMR) on a Bruker DPX 400 or DRX 700 instrument. The reference used on the ppm scale was 1 tetramethylsilane in a solvent having a 1H-NMR chemical shift of 0 ppm. Alternatively, C6D5H present in the NMR solvent was used as the reference signal (7.15 ppm, 1 1H-NMR), or the solvent signal itself ( 13 the central signal of a 1:1:1 triplet at 128.0 ppm in 13C NMR). 15 The 15N-NMR chemical shift was measured using (liquid) ammonia (0 ppm) as an external reference. 1 1H- 15 15N-HMBC measurements were determined indirectly.

[0066] The dynamic viscosity was determined at 23 °C using an MCR 501 rheometer (manufactured by Anton Paar) in accordance with DIN EN ISO 3219:1994-10. Measurements at different shear rates were ensured that Newtonian flow behavior could be assumed. Therefore, details regarding the shear rate can be omitted.

[0067] The NCO content was determined by titration in accordance with DIN EN ISO 10283:2007-11.

[0068] The residual monomer content was determined by gas chromatography using an internal standard in accordance with DIN EN ISO 10283:2007-11.

[0069] The content of acidic chlorine compounds and the content of hydrolyzable chlorine were determined in accordance with the ISO 15028:2014 standard.

[0070] GC-MS was performed using an Agilent GC6890 equipped with an MN 725825.30 Optima-5MS Accent capillary column (30 m, 0.25 mm inner diameter, 0.5 μm film layer thickness) and a 5973 mass spectrometer as the detector using helium as the carrier gas (flow rate of 2 ml / min). The column temperature was initially 60 °C (2 minutes) and was gradually increased to 360 °C at 8 K / min. GC-MS detection was performed using electron impact ionization with an ionization energy of 70 eV. An injector temperature of 250 °C was selected.

[0071] Size exclusion chromatography (SEC) was carried out in accordance with DIN 55672-1:2016-03 using tetrahydrofuran as the eluent.

[0072] X-ray crystal structure analysis was performed at 106 - 107 K on an Oxford Diffraction Xcalibur equipped with a CCD area detector (Ruby model), a Cu Kα source, and an osmium mirror as the monochromator. The CrysAlis software program, version 1.171.38.43 (Rigaku 2015), was used for data acquisition and reduction. The SHELXTL version 6.14 (Bruker AXS, 2003) was used for structure analysis.

[0073] The Hazen color number was measured spectrophotometrically in accordance with DIN EN ISO 6271-2:2005-03 using a Lico 400 spectrophotometer from Lange, Germany.

[0074] All reactions were carried out under a nitrogen atmosphere in a glass apparatus previously dried under reduced pressure at 150 - 200 °C.

[0075] The diisocyanate used is a product of Covestro. All other commercially available chemicals were obtained from Aldrich, D-82018 Taufkirchen.

[0076] 1,5-Diamino-3-oxapentane (OBDA) was obtained from BASF SE. TEFUDA, (3R,3aR,6S,6aR)-hexahydrofuro[3,2-b]furan-3,6-diamine (ISODA) and (3S,3aR,6S,6aR)-hexahydrofuro[3,2-b]furan-3,6-diamine (IDDA) were prepared from the corresponding hydroxyl compounds based on the literature method: S. Thiyagarajan, L. Gootjes, W. Vogelzang, J. van Haveren, M. Lutz, D. S. van Es ChemSusChem 2011, 4, 1823 - 1829).

[0077] General Procedure A Liquid Phase Phosgenation (LPP) A four-necked flask equipped with a mechanical stirrer, a dropping funnel, an internal thermometer, and a gas inlet tube, cooled to -5 °C, was first charged with 500 ml of monochlorobenzene (MCB), and then twice the molar amount of phosgene was condensed based on the diamine (mixture) to be reacted, and the solution of each amine (mixture) was slowly added dropwise to the MCB, and further cooled to -10 to a maximum of 0 °C. After adding all the amines (mixture), the dropping funnel was filled with 100 ml of MCB, which was similarly added dropwise to the reaction mixture. While introducing phosgene (about 120 g / h) through the gas inlet tube, the temperature was gradually increased until the reflux of MCB occurred. Once the boiling temperature was reached, stirring was continued under reflux while passing phosgene through the mixture (about 120 g / h) until a clear solution was formed, but for at least 5 hours. For dephosgenation, stirring was continued under reflux, but dry nitrogen was passed through the mixture instead of phosgene through the gas inlet tube until the absence of phosgene was ensured by phosgene indicator paper. Further work-up is described in each example.

[0078] B Gas Phase Phosgenation (GPP) In a glass system comprising a heatable mixing tube with a diameter of 2.5 mm and a length of 17.5 mm, a downstream condensation stage, and a subsequent phosgene adsorption tower filled with activated carbon, phosgene preheated in an upstream heat exchanger was continuously introduced through a nozzle protruding into the mixing tube. At the same time, an amine mixture preheated in the same way at a metering rate optimized according to a specific amine (mixture) was introduced into the reaction space through an annular gap between the nozzle and the mixing tube, which was optionally diluted with dry nitrogen as a similarly preheated diluent. By applying a reduced pressure at the end of the condensation stage, it became possible to maintain a defined pressure in the mixing tube. The gaseous hot reaction mixture exiting the reaction space was led to the condensation stage by 1,2-dichlorobenzene boiling under reflux. This resulted in the selective condensation of the formed diisocyanate. The gas mixture passing through the washing stage consisted essentially of nitrogen, HCl, and excess phosgene, and then the phosgene was removed in the adsorption tower, and residual dissolved phosgene was removed from the condensate as described in A. Further post-treatment is described in each example.

[0079] Example 1 (Comparative experiment) a) Liquid-phase phosgenation of OBDA, b) Co-phosgenation of OBDA and MDA according to DE2249459, and b) Co-phosgenation of IDDA and MDA according to DE2249459.

[0080] a) 20.83 g (0.2 mol) of OBDA was dissolved in approximately 400 ml of MCB and phosgenated according to General Procedure A. The reaction mixture thus obtained was examined by GC / GC-MS. In addition to the solvent, three main components, 2-chloroethyl isocyanate, 2-(2-chloroethoxy)ethyl isocyanate, and OBDI, were detected in a mutual ratio of 3:1:47. After removing the low-boiling substances (monochlorobenzene and 2-chloroethyl isocyanate) under reduced pressure using a column with an inner diameter of approximately 25 mm and a length of 40 cm filled with #1 Interpack random packing, the remaining mostly solvent-free distillation residue was immediately subjected to trap-to-trap distillation at 0.1 mbar and a pot temperature of 120 - 180 °C. As a result, 10.5 g of a dark brown, highly viscous distillation residue with an NCO content of 10.8% and 15.2 g of a light-colored distillate with an NCO content of 53.0% and an AC / HC content of 220 / 560 ppm were obtained. According to NMR and GC-MS, this distillate was composed of approximately 98% OBDI and approximately 2% 2-(2-chloroethoxy)ethyl isocyanate (the yield of OBDI based on the amine used was approximately 50%). After several days, the liquid, which was previously almost colorless, changed color significantly. This product is not suitable for further problem-free use in typical polyurethane applications.

[0081] b) A mixture of 4.17 g (0.04 mol) of OBDA and 31.78 g of MDA was dissolved in about 400 ml of monochlorobenzene and phosgenated according to General Procedure A. The reaction mixture thus obtained was examined by GC / GC-MS. In addition to the solvent and aromatic isocyanates, three main components, 2-chloroethyl isocyanate, 2-(2-chloroethoxy)ethyl isocyanate, and OBDI, were detected in a mutual ratio of 8.5:1:139. After removing the low boilers (monochlorobenzene and 2-chloroethyl isocyanate) under reduced pressure in a column with an inner diameter of about 25 mm and 40 cm filled with #1 Interpack random packing, the remaining mostly solvent-free distillation residue was immediately subjected to trap-to-trap distillation at 0.1 mbar and a still temperature of 120 - 180 °C. As a result, 29.5 g of a dark brown, highly viscous distillation residue with an NCO content of 26.8% was obtained, which was not analyzed further (mostly polymeric MDI). Also, 12.7 g of a yellow distillate with an NCO content of 40.0% was obtained. According to NMR and GC-MS, this distillate contained, in addition to about 31.3% OBDI, about 0.2% 2-(2-chloroethoxy)ethyl isocyanate, and about 68.1% bicyclic MDI (three different isomers, mainly the 4,4'-isomer), other unconfirmed impurities (the yield of OBDI based on the OBDA used was about 64%). The high content of cleavage products (2-chloroethyl isocyanate, 2-(2-chloroethoxy)ethyl isocyanate) and the low yield of OBDI demonstrate that the procedure according to DE2249459 does not lead to success when using the primary amine (amine 1).

[0082] c) A mixture of 5.8 g (0.04 mol) of IDDA and 32.0 g of MDA was dissolved in about 1000 ml of monochlorobenzene and phosgenated according to General Procedure A. The reaction mixture thus obtained had most of the solvent removed under reduced pressure with a rotary evaporator and was then immediately subjected to trap-to-trap distillation at 0.1 mbar and a bath temperature of 120 - 180 °C. This gave 20.8 g of a dark brown, highly viscous distillation residue with an NCO content of 28.0%, consisting mainly of polymeric MDI according to GPC and NMR, and 27.6 g of a yellowish distillate containing approximately 25% IDDI, approximately 75% bicyclic MDI (three different isomers, mainly the 4,4'-isomer) according to NMR and GC-MS, and other unconfirmed impurities. The distillation separation of this mixture was not successful. Even after repeated recrystallization from hot isooctane, residual amounts of aromatic diisocyanate remained in the IDDI. The procedure according to DE2249459 does not result in success when using the first amine (Amine 1).

[0083] Example 2 (Comparative experiment) Preparation of IDDI from IDDA by LPP without the second amine 28.5 g (0.2 mol) of IDDA was phosgenated according to General Procedure A. The reaction mixture thus obtained had most of the solvent removed under reduced pressure with a rotary evaporator and was then immediately subjected to trap-to-trap distillation at 0.1 mbar and a bath temperature of 120 - 180 °C. This gave 12.2 g of a dark brown, highly viscous distillation residue and 21.3 g of a light-colored distillate, which crystallized after a while and was composed of approximately 98% IDDI according to a combination of analytical methods (NMR, GC-MS) (53% yield based on the amine used, AC / HC: 616 / 758 ppm). After storage for several days at room temperature excluding air, the solid, which had previously been almost colorless, changed color significantly. This product is not suitable for further problem-free use in typical polyurethane applications.

[0084] Example 3 (According to the present invention): CoPg-LPP of IDDA (first amine) and PACM20 (second amine) 33.7 g (0.16 mol) of PACM20 and 5.8 g (0.04 mol) of IDDA were phosgenated according to General Procedure A. The reaction mixture thus obtained was subjected to solvent removal almost completely with a rotary evaporator under reduced pressure and then immediately to trap-to-trap distillation at a bath temperature of 0.1 mbar and 120 - 180 °C. Thereby, 6.2 g of a dark brown highly viscous distillation residue and 45.7 g of a light-colored distillate were obtained, which, after a while, a crystalline substance precipitated, and according to a combination of analytical methods (NMR, GC-MS), about 13% was IDDI and 84% was H 12 -MDI (78% and 91% yields based on the amine used). Subsequent fractional distillation gave 5.6 g of a colorless rapidly crystallizing distillate (boiling point 83 °C, melting point 42 °C at 0.1 mbar), which showed no tendency to discolor even after being stored at room temperature for several weeks with air excluded and was proven to be very suitable for use without further problems in typical polyurethane applications.

[0085] Example 4 (Comparative experiment) Preparation of ISODI from ISODA with LPP without "secondary amine" 28.8 g (0.2 mol) of ISODA was phosgenated according to General Procedure A. The reaction mixture thus obtained was subjected to solvent removal almost completely with a rotary evaporator under reduced pressure and then immediately to trap-to-trap distillation at a bath temperature of 0.1 mbar and 120 - 180 °C. Thereby, 15.1 g of a dark brown highly viscous distillation residue and 26.0 g of a light-colored distillate were obtained (66% yield based on the amine used), and according to a combination of analytical methods (NMR, GC-MS), it was composed of approximately 98% ISODI. The titrated NCO content was 42.2% and the AC / HC value was 904 / 1548 ppm. After several days, the distillate, which had previously been almost colorless, changed color significantly and was dark brown after being stored at room temperature for several weeks with air excluded. This product is unsuitable for use without further problems in typical polyurethane applications.

[0086] Example 5(According to the present invention): CoPg-LPP of IDDA (primary amine) and IPDA (secondary amine) 5.8 g (0.04 mol) of IDDA and 33.7 g (0.16 mol) of IPDA were phosgenated according to General Procedure A. The reaction mixture thus obtained had most of the solvent removed by rotary evaporator under reduced pressure and was then immediately subjected to trap-to-trap distillation at 0.1 mbar and a bath temperature of 120 - 180 °C. This gave 3.6 g of a dark brown, highly viscous distillation residue and 40.6 g of a light-colored distillate, which, according to a combination of analytical methods (NMR, GC-MS), consisted of approximately 16.7% ISODI and approximately 83.3% IPDI (yields of 86% and 95% based on the amines used). The AC / HC content of this mixture was 42 / 132 ppm.

[0087] Example 6 (Comparative experiment) H from PACM20 by GPP according to General Procedure B 12 - Preparation of -MDI (Experiments a and b), and preparation of IPDI from IPDA (Experiment c) a) In a preheated gas-phase tubular reactor at 350 °C, 141 g of PACM20 (0.67 mol) was reacted with 580 g of phosgene (5.86 mol) at 500 mbar over 2 hours. The two material streams were evaporated and heated to 350 °C at the same pressure in a heat exchanger. For better amine evaporation, 60 l / h of nitrogen was passed through the amine evaporator as a carrier gas stream. Immediately after the start of the reaction, the formation of crusts and precipitates was clearly observed at the amine inlet and in the reaction tube. An exact final weighing after the experiment showed that it was 8 g of solid.

[0088] b) In a gas-phase tubular reactor preheated to 450 °C, 139 g of PACM20 (0.66 mol) was reacted with 581 g of phosgene (5.87 mol) at 500 mbar over 2 hours. The two material streams were evaporated and heated to 450 °C at the same pressure in a heat exchanger. To achieve better amine evaporation, 60 l / h of nitrogen was passed through the amine evaporator as a carrier gas stream. Compared to Example 6a, the amount of crust and precipitate formed was significantly less. After the experiment, only a very thin, distinguishable coating was present on the walls of the reactor, and reweighing showed that the amount was 1.3 g.

[0089] c) In a gas-phase tubular reactor preheated to 350 °C, 170 g of IPDA (1.0 mol) was reacted with 622 g of phosgene (6.29 mol) at 500 mbar over 2 hours. The two material streams were evaporated and heated to 350 °C at 500 mbar in a heat exchanger. To achieve better amine evaporation, 30 l / h of nitrogen was passed through the amine evaporator. Only minimal crust and precipitate formation were observed at the amine inlet and in the reaction tube after the start of the reaction. This was determined after the experiment, and the amount was 0.5 g.

[0090] The mixtures obtained in a and b were 1 examined by 1H-NMR, and as a result, in addition to the solvent and H 12 -MDI, an appropriate proportion of olefins was found to be present and was identified by GC-MS as cyclohexenylmethylcyclohexyl isocyanate (several isomers). In Example 6b, the ratio of this unwanted by-product to the target compound H 12 -MDI was significantly lower than in the case of 6a: 67:1 compared to 4:1 (weight of H 12 -MDI: weight of olefin).

[0091] As described in Examples 2 to 5, the solvent was removed, and then trap-to-trap distillation was performed. In a), 6.15 g of a dark brown viscous distillation residue and 140.4 g of a light-colored distillate were obtained. Then, after fractionation using a 40 cm vacuum-jacketed Vigreux column having an inner diameter of about 25 mm, a colorless main fraction having a constant boiling point of 123.6 g and an NCO content of only 30.3% was obtained (H based on PACM20 used) 12 -yield of MDI < 70%). In b), 2.8 g of residue and 163 g of a final distillate having an NCO content of 31.8% were obtained (H based on PACM20 used) 12 -yield of MDI 93%).

[0092] Example 7 (According to the present invention): CoPg-GPP of TEFUDA (first amine or amine 1) and PACM20 (second amine or amine 2) by GPP according to general procedure B.

[0093] According to Example 6b, a mixture of TEFUDA (amine 1) and PACM20 (amine 2) was phosgenated according to general procedure B. In this case, at the start of the experiment, pure amine 2 (~0.335 mol / h) was metered in together with a molar excess of phosgene of about 250%. After an experimental time of 30 minutes, amine 1 was replenished so that an amine mixture consisting of 25 mol% of amine 1 and 75 mol% of amine 2 was metered in. In further experiments, the concentration of amine 1 was further increased so that amine mixtures containing 50 mol% amine 1 / 50 mol% amine 2 and 75 mol% amine 1 / 25 mol% amine 2 were used. A total of 782.6 g (6 mol) of TEFUDA and 1431.1 g (6.8 mol) of PACM20 were processed. The metered amounts, the phosgene excess used, and the run times are shown in the following table.

[0094]

Table 1

[0095] The dephosgenated crude product was 1Examined by H-NMR spectroscopy and then combined. H 12 -MDI: Regarding the olefin ratio, the ratio of undesirable compounds was significantly reduced in all experimental runs 7-1 to 7-7 compared to the more favorable Comparative Example 6b, and the average was found to be only 146:1. No significant difference in this ratio was observed among experimental runs 7-1 to 7-7.

[0096] In the post-treatment as described in Example 6, TEFUDI and H 12 -MDI: For the final separation of -MDI, a more effective column (a 40 cm column packed with #1 Interpack random packing, inner diameter approximately 25 mm) was used, so 53.9 g of a dark brown highly viscous distillation residue and 980.5 g of TEFUDI and 1674.2 g of H 12 -MDI alone were obtained. According to the combination of analysis methods (NMR, GC-MS), both were light-colored liquids composed of TEFUDI or H 12 -MDI (isomer mixture) in an amount exceeding 99% (yield 90% and yield 94% respectively based on the amines used). The AC / HC content was 35 / 318 ppm (TEFUDI) and 29 / 87 ppm (H 12 -MDI). No discoloration was observed even after removing air and storing for several weeks.

[0097] Example 8 (According to the present invention): CoPg-GPP of ISODA (first amine or amine 1) and PACM20 (second amine or amine 2) by GPP according to General Procedure B.

[0098] Following the procedure from Example 7, a mixture of ISODA (amine 1) and PACM 20 (amine 2) was phosgenated in a gas-phase phosgenation apparatus. In Experiment 8-1, at the start of the experiment, pure amine 2 (~0.5 mol / h) was metered in together with a molar excess of phosgene of about 250%. After 30 minutes of experimental time, amine 1 was replenished such that an amine mixture consisting of 25 mol% amine 1 and 75 mol% amine 2 was metered in. Such a stepwise increase of 25 mol% was carried out a total of 2 times, and in each case, after a further 30 minutes, 2 hours after the start of the experiment, an amine mixture consisting of 75 mol% amine 1 and 25 mol% amine 2 was metered in and then kept constant until the end of the experiment after a total run time of 6.25 hours. In subsequent experiments, after the first stage using pure amine 2, an amine mixture consisting of 50 mol% amine 1 and 50 mol% amine 2 was immediately metered in and maintained until the end of the experiment. Furthermore, the phosgene excess decreased from experiment to experiment, with a tendency for a decrease in reactor deposits. The amounts added, the phosgene excess used, and the run times in the individual experiments are shown in the following table. In total, 1353.9 g (9.39 mol) of ISODA and 915.0 g (4.35 mol) of PACM20 were processed.

[0099]

Table 2

[0100] The dephosgenated crude product was 1 examined by 1H-NMR spectroscopy and then combined. H 12 -MDI: With respect to the olefin ratio, the ratio of undesired compounds was also found to be significantly reduced, being only 127:1 on average, compared to the more favorable Comparative Example 6b. Here too, no significant difference in this ratio was observed in Experimental Runs 8-1 to 8-5.

[0101] Workup as described in Example 7 gave 60.1 g of a dark brown highly viscous distillation residue and, as a light-colored liquid, 1795.8 g of ISODI and 993.1 g of H 12-Only MDI was given, and according to the combination of analytical methods (NMR, GC-MS), they were >99% ISODI or H 12 -MDI (isomer mixture) (yield 97.5% and yield 87.0% based on the amine used). The AC / HC content was 27 / 178 ppm (ISODI) and 15 / 152 ppm (H 12 -MDI). Even after removing air and storing at room temperature for several weeks in any of the products obtained according to the present invention, no discoloration was observed.

[0102] Example 9 a) Two comparative experiments of GPP of OBDA b) According to the present invention, CoPg-GPP of OBDA (first amine) and IPDA (second amine) by GPP according to general procedure B a) In two separate experiments, OBDA and phosgene were reacted at 500 mbar in a gas-phase tube reactor preheated to 350 °C. The two material streams were evaporated and heated to 350 °C at 500 mbar in a heat exchanger. For better amine evaporation, 30 l / h of nitrogen was passed through the amine evaporator as a carrier gas. In the first comparative experiment, 325 g of OBDA (3.1 mol) was reacted with 1376 g of phosgene (13.9 mol) over 3.8 hours. In the second comparative experiment, 312 g of OBDA (3.0 mol) and 1219 g of phosgene (12.3 mol) were metered in over 3.5 hours, and the reactor deposits reaching 9 g after the experiment were determined.

[0103] By post-treatment as described in Example 6, 185 g of a dark brown highly viscous distillation residue and 723.0 g of OBDI were obtained as a light-colored liquid, but according to the combination of analytical methods (NMR, GC-MS), it was composed of more than 98% OBDI (yield 76% based on the amine used). The AC / HC content was 90 / 793 ppm. During storage at room temperature with air removed for several weeks, the product underwent significant discoloration. The color number increased from the initial 8 APHA immediately after distillation treatment to 520 APHA after 3 weeks.

[0104] b) According to Example 6c, an amine mixture consisting of 118.4 g of OBDA (1.14 mol) and 355.3 g of IPDA (2.09 mol) was metered into a gas-phase tubular reactor preheated to 350° C. over 6 hours and reacted with 2223 g of phosgene (22.47 mol) at a system pressure of 500 mbar. The two material streams were evaporated and heated to 350° C. at 500 mbar in a heat exchanger. For better amine evaporation, nitrogen at 30 l / h was passed through the amine evaporator. Downstream of the reactor, the reaction mixture was quenched in boiling o-dichlorobenzene and dephosgenated by nitrogen stripping. The formation of solid material at the amine inlet and in the reaction tube was determined after the experiment and reached 4 g.

[0105] When post-treated as described in Example 6, 12 g of a dark brown, highly viscous distillation residue, 169 g of OBDI, and 442 g of IPDI were obtained as a light-colored liquid, which according to a combination of analytical methods (NMR, GC-MS) consisted of more than 99% of OBDI or IPDI (isomer mixture) (yield 95% in each case based on the amines used). The AC / HC content was 19 / 114 ppm (OBDI) and 12 / 212 ppm (IPDI). Even after several weeks of storage at room temperature with air removed, no discoloration was observed in any of the products obtained according to the invention.

[0106] Example 10 (According to the present invention): CoPg-GPP of ISODA (primary amine) and OBDA (secondary amine) 42.2 g of OBDA (0.4 mol) and 152 g of phosgene (1.54 mol) were first metered into a preheated gas-phase tubular reactor at 350 °C over 30 minutes. Subsequently, an amine mixture consisting of 54.0 g of ISODA (0.37 mol) and 117.3 g of OBDA (1.13 mol) was metered in over 3 hours and reacted with 933 g of phosgene (9.43 mol) at a system pressure of 500 mbar. The two material streams were vaporized and heated to 350 °C at 500 mbar in a heat exchanger. For better amine evaporation, 60 l / h of nitrogen was passed through the amine evaporator as a carrier gas stream. Downstream of the reactor, the reaction mixture was quenched in boiling o-dichlorobenzene and degassed by nitrogen stripping. The formation of solids at the amine inlet and in the reaction tube was determined after the experiment and reached 8.3 g.

[0107] When post-treated as described in Example 6, only 16.6 g of a dark brown, highly viscous distillation residue, 49.8 g of ISODI, and 199.9 g of OBDI were obtained as a light-colored liquid and consisted of more than 99% of ISODI or OBDI according to a combination of analytical methods (NMR, GC-MS) (yield 68% and yield 84% respectively based on the amines used). In any of the products obtained according to the invention, no discoloration was observed even after air was removed and stored at room temperature for several weeks.

[0108] Many attempts to react TEFUDA, IDDA, or ISODA by GPP without "amine 2" failed after a maximum run time of 60 minutes. Continuous solidification occurred, and due to the pressure increase in the system, it was necessary to stop after an unacceptably short run time. The ISODI produced in these runs at a very low yield was of completely unacceptable quality and could only be purified in an extremely laborious manner.

Claims

1. A method for producing an isocyanate by phosgenating a corresponding amine, comprising reacting an amine mixture formed from at least one first amine and at least one second amine different from the first amine with phosgene to obtain a reaction mixture, - The first amine contains at least one ether group, and The secondary amine is selected from the group consisting of aminoalkanes having 5 to 15 hydrocarbon atoms and not containing an ether group. or - The first amine contains at least one cyclic ether group, and A method characterized in that the secondary amine contains at least one open-chain ether group and does not contain a cyclic ether group.

2. A first amine containing at least one ether group has the general formula X-(-R １ -NH ｍ ) ｎ (In the formula, - X is H, NH ｍ or C(R) ２ ) ｐ And, - R １ R is a substituted and / or heteroatom-containing aliphatic, (cyclo)aliphatic, or aromatic radical, preferably having up to 10 carbon atoms, where R １ It contains at least one ether group, -R ２ is H or an optionally substituted and / or heteroatom-containing aliphatic, (cyclo)aliphatic or aromatic radical, preferably having up to 10 carbon atoms, - m is 1 or 2, - n is 1, 2, or 3, and (p is 1, 2, or 3) The method according to claim 1, characterized by including the structure.

3. The method according to claim 1 or 2, characterized in that a first amine containing at least one ether group, a first amine containing at least one cyclic ether group, a second amine comprising an aminoalkane having 5 to 15 hydrocarbon atoms, and / or a second amine containing at least one open-chain ether group and not containing a cyclic ether group, is a diamine.

4. The first amine containing at least one ether group is (tetrahydrofuran-2,5-diyl)methaneamine, 3,6-diaminohexahydroflou[3,2-b]furan, 3,6-bis(aminomethyl)hexahydroflou[3,2-b]furan, furan-2,5-diylmethaneamine, (methane-2,2-diylbis(tetrahydrofuran-5,2-diyl))methaneamine, (methane-2,2-diylbis(furan-5,2-diyl))methaneamine, (propane-2,2-diylbis(tetrahydrofuran-2,5-diyl) Selected from the group consisting of di(aminopropyl) ethers or mixtures thereof, (propane-2,2-diylbis(furan-5,2-diyl))methaneamine; di(aminoethyl) ethers, particularly 2,2'-oxybis(ethane-1-amine), 1,1'-oxybis(propane-2-amine), 2-(2-aminoethoxy)propane-1-amine, 2,2'-oxybis(propane-1-amine), and 2-(2-aminopropoxy)propane-1-amine; di(aminopropyl) ethers or mixtures thereof. and / or The method according to claim 1 or 2, characterized in that the first amine containing at least one cyclic ether group is selected from the group consisting of (tetrahydrofuran-2,5-diyl)methaneamine, 3,6-diaminohexahydrofloo[3,2-b]furan, 3,6-bis(aminomethyl)hexahydrofloo[3,2-b]furan, furan-2,5-diylmethaneamine, (methane-2,2-diylbis(tetrahydrofuran-5,2-diyl))methaneamine, (methane-2,2-diylbis(furan-5,2-diyl))methaneamine, (propane-2,2-diylbis(tetrahydrofuran-5,2-diyl))methaneamine, (propane-2,2-diylbis(furan-5,2-diyl))methaneamine, or a mixture thereof.

5. The secondary amines, which consist of aminoalkanes having 5 to 15 hydrocarbon atoms, include 1,5-diaminopentane; 1,6-diaminohexane; 1-amino-3,5,5-trimethyl-5-aminomethylcyclohexane; amino-[(aminocyclohexyl)methyl]cyclohexane, particularly 4,4'-methylenebis(cyclohexane-1-amine), 2-((4-aminocyclohexyl)methyl)cyclohexane-1-amine, and 2,2'-methylenebis(cyclohexane-1-amine); 1,3-bis(aminomethyl)cyclo The method according to claim 1 or 2, characterized in that it is selected from the group consisting of hexane; 1,4-bis(aminomethyl)cyclohexane; diaminocyclohexane, particularly cyclohexane-1,2-diamine, cyclohexane-1,3-diamine, and cyclohexane-1,4-diamine; methyldiaminocyclohexane, particularly 4-methylcyclohexane-1,3-diamine and 2-methylcyclohexane-1,3-diamine, 4,4'-methylenebis(2-methylcyclohexane-1-amine); or mixtures thereof.

6. The secondary amines containing at least one open-chain ether group and not containing a cyclic ether group are di(aminoethyl) ether, di(aminopropyl) ether, 1,8-diamino-1,5,8-trimethyl-3,6-dioxaoctane, 1,11-diamino-1,5,8,11-tetramethylundecane, 1,8-diamino-3,6-dioxaoctane, 1,10-diamino-4,7-dioxadecane, 1,12-diamino-4,9-dioxadodecane, 1,14-diamino-3,10-dioxatetradecane, 1,13-diamino-4,7,10-trioxatridecanane, 1,7-di The method according to claim 1 or 2, characterized in that it is selected from the group consisting of amino-2,6-dioxa-4-aminomethoxyheptane, 1-amino-2-oxa-3,3-bis(aminomethoxy)hexane, 1,9-diamino-3,7-dioxa-5-(1-amino-2-ethoxy)nonane, 1-amino-3-oxa-4,4-bis(1-amino-2-ethoxy)heptane, 1,11-diamino-4,8-dioxa-6-(1-amino-5-oxabutyl)undecane, 1-amino-4-oxa-5,5-bis(1-amino-5-oxabutyl)octane, or a mixture thereof.

7. Based on the total weight of the amine mixture, - The mass fraction of the primary amine is 5.0% by weight to 95.0% by weight, and The mass fraction of the secondary amine is 95.0% by weight to 5.0% by weight. The method according to claim 1 or 2, characterized in that the molar ratio of and / or phosgene to the amino groups of the amine in the amine mixture is ≥1:1 ​​to ≤5:

1.

8. An inert substance is used in the reaction, and the inert substance is • Inert gas, • Inert solvent, The method according to claim 1 or 2, characterized in that the mixture is selected from the group consisting of the aforementioned inert gas and inert solvent.

9. The method according to claim 1 or 2, characterized in that an isocyanate corresponding to a first amine and / or an isocyanate corresponding to a second amine are separated from the reaction mixture, the separation is carried out by distillation, and the corresponding isocyanates are obtained separately or as an isocyanate mixture.

10. The method according to claim 9, characterized in that the content of acidic chlorine compounds in the separated isocyanate or isocyanate mixture is determined in accordance with ISO 15028:2014 and is 1 to 100 ppm, and / or the content of hydrolyzable chlorine in the separated isocyanate or isocyanate mixture is determined in accordance with ISO 15028:2014 and is 1 to 500 ppm.

11. To reduce the content of acidic chlorine compounds and / or hydrolyzable chlorine in the corresponding isocyanate obtained in the manufacturing process, use of an amine mixture formed from at least one first amine and at least one second amine different from the first amine in a method for producing the corresponding isocyanate by phosgenation according to claim 1 or 2.

12. An isocyanate mixture that can be obtained or is obtained by the method of claim 1 or 2, or can be directly obtained or is obtained by the method of claim 1 or 2.

13. Use of the isocyanate mixture according to claim 12 as a component for the manufacture of polyurethanes, pharmaceuticals, and also as an adjuvant, emulsifier and thickener.

14. Use of isocyanates or isocyanate mixtures obtained or obtainable by the method of Claim 9, as components for the manufacture of polyurethanes, pharmaceuticals, and also auxiliaries, emulsifiers and thickeners.

15. A phosgenerating plant for carrying out the method according to claim 1 or 2, (a) At least one phosgene apparatus for continuously supplying phosgene in combination with an inert substance, (b) Optionally, an inert substance device for supplying an inert substance, (c) At least one amine apparatus for continuously supplying an amine mixture, optionally in combination with an inert substance, and (d) A plant comprising or consisting of a phosgenation reactor for mixing phosgene, an amine mixture, and optionally an inert substance, and for reacting the amine mixture with phosgene, wherein the amine apparatus comprises a first storage container for a first amine, a second storage container for a second amine, a metering device for independently and variably adjusting the mass fraction of the first amine and the second amine, and optionally a mixing device for mixing the first amine and the second amine to form an amine mixture.