Producing special isocyanates via co-phosgenation

Abstract

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

Description

[0001] Production of special isocyanates by co-phosgenation

[0002] The invention relates to a process for the preparation of isocyanates by phosgenation, in particular gas phase phosgenation (GPP) or liquid phase phosgenation (FPP), of the corresponding amines, wherein an amine mixture of 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 in which in particular a higher yield and / or good purity (in the form of a reduction in the content of acidic chlorine compounds (AC value) and / or hydrolyzable chlorine (HC value)) of the corresponding isocyanates obtained in the preparation are achieved.Furthermore, the invention relates to a product obtainable or obtained by the process according to the invention, preferably a product directly obtainable or obtained by the process according to the invention, and to the use of this product and / or the isocyanate or isocyanate mixture obtained or obtainable by the process according to the invention. Furthermore, the invention relates to a phosgenation plant for carrying out the process according to the invention.

[0003] Isocyanates, especially diisocyanates, and occasionally low-molecular-weight triisocyanates, as well as the higher-molecular-weight polyaddition products with terminal isocyanate groups accessible from the above-mentioned compounds, are valuable raw materials for the production of polyurethanes. Isocyanates are produced technically advantageously by phosgenation of the underlying amines, both in the condensed phase (liquid phosgenation, hereinafter referred to as FPP) and in the gas phase (gas phase phosgenation, hereinafter referred to as GPP). The latter is only feasible for amines that can be evaporated without decomposition under the selected pressure. In general, it has been shown that many isocyanates that cannot be produced using FPP, or can only be produced in poor yields or with unsatisfactory purity, can be produced more effectively using GPP. This applies in particular to diisocyanates that carry sensitive functional groups, such as ether bridges, in the molecular structure (cf.EP-A 764633 and sources cited therein).

[0004] Although some isocyanates containing ether groups can be produced using GPP in good yields and high purity, this is by no means true for all technically relevant species of this substance class. For example, the acidity or content of acidic chlorine compounds (hereinafter also referred to as AC, AC value, AC content) and the hydrolyzable chlorine content (hereinafter also referred to as HC, HC value, HC content) of l,5-diisocyanato-3-oxapentane (hereinafter OBDI) are not sufficiently low to allow trouble-free further processing of this diisocyanate in typical polyurethane applications (see comparative examples). Further examples are (poly)cyclic amines containing ether groups with cyclic ether building blocks such as sugar derivatives of the furan, dihydrofuran, tetrahydrofuran, sorbitol, mannitol and iditol series (isohexides), whereby it is irrelevant whether the amino groups are bonded to the (poly)cycle directly or via further bridge atoms.Distillative separation of the HC-bearing impurities is difficult, if not impossible, for many of these compounds, especially for OBDI.

[0005] The object of the present invention was therefore to provide a process for producing isocyanates by phosgenation (gas-phase and / or liquid-phase phosgenation) of the corresponding amines, as well as a phosgenation plant for carrying out this process. In particular, a further object of the present invention was to convert amines (hereinafter also referred to as "amine(s) 1" or "first amine") that are "problematic" with regard to phosgenation into the corresponding isocyanates (hereinafter also referred to as "isocyanate(s) 1") in a technically feasible manner. In particular, a high yield and / or good purity in the form of a reduction in the content of acidic chlorine compounds (AC value) and / or hydrolyzable chlorine (HC value) of the corresponding isocyanates obtained during production should be achieved.

[0006] This object was achieved by a process for the preparation of isocyanates by phosgenation of the corresponding amines, wherein an amine mixture of 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, characterized in that either

[0007] • the first amine contains at least one ether group; and

[0008] • the second amine is selected from the group comprising or consisting of aminoalkanes having 5 to 15 hydrocarbon atoms which do not contain ether groups; or

[0009] • the first amine contains at least one cyclic ether group; and

[0010] • the second amine contains at least one open-chain ether group and no cyclic ether groups.

[0011] Furthermore, the invention relates to the use of an amine mixture of at least one first amine and at least one second amine different from the first amine in a process for preparing the corresponding isocyanates by phosgenation according to the process according to the invention for reducing the content of acidic chlorine compounds and / or the content of hydrolyzable chlorine of the corresponding isocyanates obtained in the preparation.

[0012] Furthermore, the invention relates to a product obtainable or obtained by the process according to the invention, preferably directly obtainable or obtained by the process according to the invention.

[0013] Furthermore, the invention relates to the use of the product according to the invention and / or the isocyanate or isocyanate mixture obtained or obtainable by the process according to the invention as a component for the production of polyurethanes, in particular polyurethane foams, polyurethane coatings and polyurethane adhesives, of pharmaceutical products, in particular active ingredients, and of auxiliaries, in particular auxiliaries for the wet strength finishing of paper and other cellulose products, emulsifiers and thickeners.

[0014] The invention also relates to a phosgenation plant for carrying out the process according to the invention, comprising or consisting of

[0015] (a) at least one phosgene device for the continuous provision of phosgene, optionally in combination with an inert substance

[0016] (b) where appropriate, an inert material device for providing an inert material,

[0017] (c) at least one amine device for the continuous provision of an amine mixture, optionally in combination with an inert substance

[0018] (d) a phosgenation reactor for mixing the phosgene and the amine mixture and optionally the inert substance and reacting the amine mixture with the phosgene, characterized in that the amine device comprises a first storage container for a first amine and a second storage container for a second amine and a metering device for independently variable adjustment of 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 the amine mixture.

[0019] Surprisingly, it was found that mixtures of amines 1 ("first amine") and amines that are unproblematic with regard to phosgenation (hereinafter also referred to as "amines 2" or "second amine") can be converted into the corresponding mixtures of isocyanate(s) 1 and isocyanate(s) 2 far more easily than is the case with the sole phosgenation of amines 1. This process according to the invention is also referred to hereinafter as co-phosgenation, or CoPg for short. The resulting isocyanates 2 are at least equivalent in terms of yield and quality (in particular the content of acidic chlorine compounds (AC value) and / or hydrolyzable chlorine compounds (HC value)) to those resulting from the sole phosgenation of amines 2.What is particularly surprising, however, is that the diisocyanates 2 accessible from the amines 2 are also obtained in significantly higher purity by the process according to the invention than is the case with their sole phosgenation under otherwise comparable conditions. Further details can be found in the working examples. Furthermore, it was found that amines with open-chain ether groups are relatively less problematic with regard to phosgenation than amines with cyclic ether groups. Here, too, it has been shown within the framework of the process according to the invention that the same aforementioned improvements in yield and quality (in particular the content of acidic chlorine compounds (AC value) and / or hydrolyzable chlorine compounds (HC value)) can be observed with an amine mixture consisting of an amine with at least one cyclic ether group and an amine with exclusively open-chain ether groups.In the context of the invention, the content of acidic chlorine compounds and the content of hydrolyzable chlorine are determined according to the standard ISO 15028:2014.

[0020] Even though the phosgenation of isomer mixtures, e.g. of 2,4- and 2,6-diaminotoluenes to the technically established TDI, as well as the phosgenation of isomer and homolog mixtures of amines resulting from the aniline-formaldehyde condensation (MDA -> MDI) are well-known examples of the phosgenation of mixtures of different chemical entities, this approach is solely due to the fact that during the production of the underlying amines, isomer and / or homolog mixtures are produced, which do not appear to be economically or technically viable to separate into their individual components. Instead, the possibility of separating the isomers into their individual components by crystallization (2,4-TDI, so-called "T 100") or distillation (monomeric MDI, e.g.4,4'-bis(isocyanatophenyl)methane, 2,4'-bis(isocyanatophenyl)methane, and 2,2'-bis(isocyanatophenyl)methane, as well as any mixtures of the three aforementioned individuals (hereinafter referred to as 2-nuclear MDI), are more easily isolated from the isocyanate mixtures in pure form than by previously separating the amine mixtures. In the aliphatic series, IPDA and the nucleus-hydrogenated 2-nuclear MDA (established acronyms: H12MDA, PACM) are examples of inevitably occurring mixtures of diamines containing regio- and / or stereoisomers, which, after phosgenation, are converted into the corresponding isomer mixtures of the diisocyanates IPDI and H12-MDI, respectively. In the latter case, the separation of the pure trans-trans-4,4'-isomer is also possible by crystallization.

[0021] A deliberately prepared mixture of two (or more) chemically completely different amines originating from completely different production processes for the purpose of phosgenation has so far only been described in DE 2249459. It is essential to the invention to use an aromatic amine 2 (within the meaning of the present application) as the "base amine" for the production of aliphatic isocyanates from the corresponding amines, in order to avoid the need to construct an expensive separate plant for the aliphatic isocyanates, which are generally required industrially in significantly smaller quantities. The solution to the above-mentioned technical problems was neither the subject of DE 2249459 nor is it solvable according to this teaching, as can be seen from the HC contents of the isocyanates described in the examples of DE 2249459 (0.1% and above).As Example 1 of the present document shows, the process of DE 2249459 is also not suitable for overcoming the problems in the production of the special isocyanates within the meaning of the present application.

[0022] It is also surprising - especially considering the mean free path between the various molecules in the gas phase on the one hand and the often high dilution in the liquid phase on the other - that the CoPg of the first and second amine (amines 1 and 2) has any beneficial influence on the overall process, apart from the obvious economic advantages discussed in DE 2249459, since no second plant is required for the production of special isocyanates with lower tonnage than is usual, for example, for MDI production.

[0023] The invention relates to a process for the preparation of isocyanates by phosgenation of the corresponding amines, wherein an amine mixture of 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, characterized in that either

[0024] • the first amine contains at least one ether group; and

[0025] • the second amine is selected from the group comprising or consisting of aminoalkanes having 5 to 15 hydrocarbon atoms which do not contain ether groups; or

[0026] • the first amine contains at least one cyclic ether group; and

[0027] • the second amine contains at least one open-chain ether group and no cyclic ether groups.

[0028] The phosgenation is preferably a gas-phase phosgenation (GPP) or liquid-phase phosgenation (FPP). The mixing ratio of the first and second amines (amines 1 and 2) can vary within wide limits in the process according to the invention (20:1 to 1:20). The mixing ratio of the first amine to the second amine is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. Even though high proportions of amine 1 in the amine mixture obviously lead to a higher yield of the resulting isocyanate 1, it may also be preferable to subject amine 1 to the CoPg reaction in a not too high proportion in admixture with amine 2 to produce particularly pure isocyanates 1.In gas-phase phosgenation, the ratio of amine 1 to amine 2 (first to second amine) can also be varied during the reaction, up to the exclusive addition of amine 2 during the start-up phase and finally the exclusive addition of amine 1 after a steady state has been reached. This special embodiment of the process takes advantage of the fact that, especially during start-up of gas-phase phosgenation, critical phases are often encountered that are better managed with amine 2 than with amine 1, and would lead to termination of the experiment if the latter were added exclusively during the start-up phase.

[0029] When selecting amines 1 and 2, care can be taken to ensure that the resulting isocyanates 1 and 2 are readily separable from one another—for example, by distillation, extraction, or crystallization. However, it is also possible to further use the mixtures of isocyanates 1 and 2—usually after distillative removal of color-imparting and high-boiling impurities—as a mixture in the form obtained in the process according to the invention. This approach is expressly excluded in DE 2249459, since it is stated there that it is essential to the invention that the (two) isocyanates should be able to be separated at the end of the process (cf. DE 2249459, p. 4, last paragraph, and claims 1-3).

[0030] 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 aminoalkanes having 5 to 15 hydrocarbon atoms and / or the second amine containing at least one open-chain ether group and no cyclic ether groups is a diamine.

[0031] The first amine containing at least one ether group preferably has a structure of the general formula X-(-R 1 -NH m )n, where

[0032] X for H, NH m or C(R 2 ) P ;

[0033] R 1 for optionally substituted and / or heteroatom-containing, aliphatic, (cyclo)aliphatic or aromatic radicals having preferably up to 10 carbon atoms, where R 1 contains at least one ether group;

[0034] R 2represents H, optionally substituted and / or heteroatom-containing, aliphatic, (cyclo)aliphatic or aromatic radicals having preferably up to 10 carbon atoms; m represents 1 or 2; n represents 1, 2 or 3; and p represents 1, 2 or 3.

[0035] In a preferred embodiment, the first amine containing at least one ether group is selected from the group comprising or consisting of (tetrahydrofuran-2,5-diyl)dimethanamine (TEFUDA), 3,6-diamino-hexahydrofuran[3,2-b]furan (e.g. IDDA and / or ISODA), 3,6-bis(aminomethyl)-hexahydrofuran[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) ethers, in particular 2,2'-oxybis(ethane-l-amine), l,l'-oxybis(propan-2-amine), 2-(2-aminoethoxy)propan-l-amine, 2,2'-oxybis(propan-l-amine) and 2-(2-aminopropoxy)propan-l-amine; di(aminopropyl) ethers or mixtures thereof. The first amine containing at least one cyclic ether group is preferably selected from the group comprising or consisting of (tetrahydrofuran-

[0036] 2.5-diyl)dimethanamine (TEFUDA), 3,6-diamino-hexahydrofiiro[3,2-b]fiirane (e.g. IDDA and / or ISODA),

[0037] 3,6-Bis(aminomethyl)-hexahydrofuran[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 mixtures thereof. It is further preferred if the second amine comprising or consisting of aminoalkane having 5 to 15 hydrocarbons is selected from the group comprising or consisting of 1,5-diaminopentane;

[0038] 1,6-diaminohexane; l-Amino-3,5,5-trimethyl-5-aminomethylcyclohexane; amino

[0039] [(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 mixtures thereof. However, a number of other amines may also be suitable as “amines 2”, which can easily be determined by simple preliminary tests.

[0040] The second amine containing at least one open-chain ether group and no cyclic ether groups is preferably selected from the group comprising or consisting of di(aminoethyl) ether, di(aminopropyl) ether, l,8-diamino-l,5,8-trimethyl-3,6-dioxaotane, 1,11-diamino-l,5,8,11-tetramethylundecane, l,8-diamino-3,6-dioxaoctane, l,10-diamino-4,7-dioxadecane, l,12-diamino-4,9-dioxadodecane, l,14-diamino-3,10-dioxatetradecane, l,13-diamino-4,7,10-trioxatridecane, 1,7-diamino-

[0041] 2,6-dioxa-4-aminomethoxy-heptane, l-amino-2-oxa-3,3-bis(aminomethoxy)hexane, l,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-(l-amino-5-oxabutyl)undecane, l-amino-4-oxa-5,5-bis(l-amino-5-oxabutyl)octane or mixtures thereof. The limiting factor regarding the usability of ether-containing mono- and polyamines in the CoPg according to the invention in the specific embodiment of gas-phase phosgenation is neither the number of (primary) amino groups nor the number of ether bonds, but rather their evaporability under the applied pressure. For particularly high-boiling compounds, it can therefore be advantageous to introduce them as azeotropes with other substances into the gas-phase phosgenation or to use a carrier gas to feed the amine mixture into the reaction space. Amine 2 can provide support in this regard.

[0042] In addition, it is preferred that the mass fraction

[0043] • of the first amine is 5.0 to 95.0 wt.%, preferably 10.0 to 80.0 wt.% and of the second amine is 95.0 to 5.0 wt.%, preferably 90.0 to 20.0 wt.%, more preferably 80.0 to 20.0 wt.%, based on the total weight of the amine mixture.

[0044] The molar ratio of phosgene to the amino groups of the amines of the amine mixture is preferably > 1: 1 to < 5: 1, preferably > 1: 1 to < 3: 1, more preferably > 1: 1 to < 2: 1.

[0045] In the reaction, it is preferred if an inert substance is additionally used, wherein the inert substance is selected from the group comprising or consisting of • inert gases, in particular nitrogen, argon or a mixture of these;

[0046] • inert solvents, in particular aromatic hydrocarbons, preferably chlorobenzene, o-dichlorobenzene, toluene, xylene or mixtures of these;

[0047] • or mixtures of the aforementioned inert gases and inert solvents.

[0048] Preferably the temperature

[0049] • in the reaction in the condensed phase, on the one hand, between -40°C and the boiling point of the solvent used or the lowest boiling starting material at the pressure set in the reaction and

[0050] • in gas phase phosgenation between the boiling point of the reactant with the highest boiling point TI at plant pressure and 600°C, preferably between TI and 550°C, more preferably between TI and 500°C.

[0051] It is also preferred that the isocyanate corresponding to the first amine and / or the isocyanate corresponding to the second amine is separated from the reaction mixture, wherein the separation is preferably carried out by means of distillation, in particular thin-film distillation, extraction, crystallization, recrystallization, or a combination thereof, and the respective isocyanates are obtained separately or as an isocyanate mixture. It is further preferred that the isocyanate corresponding to the first amine and the isocyanate corresponding to the second amine is separated from the reaction mixture, wherein the separation is preferably carried out by means of distillation, in particular thin-film distillation, extraction, crystallization, recrystallization, or a combination thereof, and the respective isocyanates are 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(s) or the isocyanate mixture is from 1 to 100 ppm, preferably from 2 to 80 ppm, particularly preferably from 5 to 50 ppm, determined according to the standard ISO 15028:2014. The content of hydrolyzable chlorine (also referred to as HC value or HC content) in the separated isocyanate(s) or the isocyanate mixture is preferably from 1 to 500 ppm, preferably from 5 to 100 ppm, determined according to the standard ISO 15028:2014.

[0052] In a preferred embodiment, the invention relates to a process for the preparation of isocyanates by phosgenation of the corresponding amines, wherein an amine mixture of 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, characterized in that either

[0053] • the first amine contains at least one ether group; and

[0054] • the second amine is selected from the group comprising or consisting of aminoalkanes having 5 to 15 hydrocarbon atoms which do not contain ether groups; or

[0055] • the first amine contains at least one cyclic ether group; and • the second amine contains at least one open-chain ether group and no cyclic ether groups, wherein the first amine containing at least one ether group is selected from the group comprising or consisting of (tetrahydrofuran-2,5-diyl)dimethanamine, 3,6-diamino-hexahydrofiiro[3,2-b]fiiran, 3,6-bis(aminomethyl)-hexahydrofiiro[3,2-b]fiiran, furan-2,5-diyldimethanamine, (methane-2,2-diylbis(tetrahydrofiiran-5,2-diyl))dimethanamine, (methane-2,2-diylbis(furan-5,2-diyl))dimethanamine, (propane-2,2-diylbis(tetrahydrofiiran-5,2-diyl))dimethanamine, (propane-2,2-diylbis(furan-5,2-diyl))dimethanamine; Di(aminoethyl) ethers, in particular 2,2'-oxybis(ethane-l-amine), l,l'-oxybis(propan-2-amine), 2-(2-aminoethoxy)propan-l-amine, 2,2'-oxybis(propan-l-amine) and 2-(2-aminopropoxy)propan-l-amine;Di(aminopropyl) ether or mixtures thereof and / or the first amine containing at least one cyclic ether group is selected from the group comprising or consisting of (tetrahydrofuran-2,5-diyl)dimethanamine, 3,6-diamino-hexahydrofuran[3,2-b]furan, 3,6-bis(aminomethyl)-hexahydrofuran[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 mixtures thereof, and the The second amine comprising or consisting of an aminoalkane having 5 to 15 hydrocarbon atoms is selected from the group comprising or consisting of 1,5-diaminopentane; 1,6-diaminohexane; 1-amino-3,5,5-trimethyl-5-aminomethylcyclohexane;Amino-[(aminocyclohexyl)methyl]cyclohexane, in particular 4,4'-methylenebis(cyclohexan-1-amine), 2-((4-aminocyclohexyl)methyl)cyclohexan-1-amine and 2,2'-methylenebis(cyclohexan-1-amine); 1,3-bis(aminomethyl)cyclohexane, 1,4-;

[0056] 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 mixtures thereof, and the second amine containing at least one open-chain ether group and no cyclic ether groups is selected from the group comprising or consisting of di(aminoethyl) ether, di(aminopropyl) ether, l,8-diamino-l,5,8-trimethyl-3,6-dioxaoctane, 1,11-diamino-l,5,8,11-tetramethylundecane, l,8-diamino-3,6-dioxaoctane, l,10-diamino-4,7-dioxadecane, l,12-diamino-4,9-dioxadodecane, l,14-diamino-3,10-dioxatetradecane, l,13-diamino-4,7,10-trioxatridecanane, 1,7-diamino-2,6-dioxa-4-aminomethoxy-heptane, l-Amino-2-oxa-3,3-bis(aminomethoxy)hexane, l,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-(l-amino-5-oxabutyl)undecane, l-amino-4-oxa-5,5-bis(l-amino-5-oxabutyl)octane or mixtures thereof. This embodiment can be combined with the other embodiments as desired, unless the context indicates otherwise.;

[0057] The invention further relates to the use of an amine mixture of at least one first amine and at least one second amine different from the first amine in a process for preparing the corresponding isocyanates by phosgenation according to a process according to one of claims 1 to 13 for reducing the content of acidic chlorine compounds and / or the content of hydrolyzable chlorine of the corresponding isocyanates obtained in the preparation.

[0058] A further object of the present invention is a product obtainable or obtained by the process according to the invention, preferably directly obtainable or obtained by the process according to the invention.

[0059] The present invention also relates to the use of the product according to the invention and / or the isocyanate or isocyanate mixture obtained or obtainable by the process according to the invention as a component for the production of polyurethanes, in particular polyurethane foams, polyurethane coatings and polyurethane adhesives, of pharmaceutical products, in particular active ingredients, and of auxiliaries, in particular auxiliaries for the wet strength finishing of paper and other cellulose products, emulsifiers and thickeners.

[0060] The GPP process according to the invention is carried out in its basic features using a method known per se from the prior art, e.g. according to the teaching of EP 0 570 799 or EP 0 676 392 and process variants cited therein. For this purpose, the reactants are introduced into suitable reactors near or above the boiling point of the starting amine (mixture), mixed, and reacted with one another. The temperatures for this are, depending on the selected pressure, between 100 and 600 °C, preferably between 150 and 500 °C. The process is carried out in a pressure range between 10 mbar and 5 bar, preferably 200 mbar and 3 bar. The reaction components can be added during the gas-phase phosgenation with or without the use of additives inert to the phosgenation reaction, such as carrier gases. Suitable carrier gases include nitrogen, argon, or other inert gases, as well as vapors of industrially available solvents, such asChlorobenzene, dichlorobenzenes, xylenes, chlorophthalenes, decahydronaphthalene, etc., are suitable.

[0061] The isocyanate mixtures according to the invention are then obtained by cooling the gas stream to a temperature above the decomposition temperature of the corresponding intermediate carbamic acid chlorides. 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, wherein the separation is preferably carried out by means of distillation, in particular thin-film distillation, extraction, crystallization, recrystallization or a combination thereof, and the respective isocyanates are obtained separately or as an isocyanate mixture. Particular preference is given to separating the isocyanate corresponding to the first amine and the isocyanate corresponding to the second amine from the reaction mixture. It is further preferred that the separation is carried out by means of distillation, optionally followed by recrystallization.The process products according to the invention are valuable raw materials for the production of polyurethanes, adhesives, coating materials, oligomeric isocyanate modification products such as 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, as emulsifiers, thickeners, etc., as raw materials for the production and / or formulation of active ingredients, pharmaceuticals, etc.

[0062] Finally, the invention also relates to a phosgenation plant for carrying out the process according to the invention, comprising or consisting of

[0063] (a) at least one phosgene device for the continuous provision of phosgene, optionally in combination with an inert substance

[0064] (b) where appropriate, an inert material device for providing an inert material,

[0065] (c) at least one amine device for the continuous provision of an amine mixture, optionally in combination with an inert substance

[0066] (d) a phosgenation reactor for mixing the phosgene and the amine mixture and optionally the inert substance and reacting the amine mixture with the phosgene, characterized in that the amine device comprises a first storage container for a first amine and a second storage container for a second amine and a metering device for independently variable adjustment of 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 the amine mixture.

[0067] The phosgene flow device, the optional inert material flow device, the amine flow device and the phosgenation reactor can independently comprise further apparatus which are useful for the operation of the phosgenation plant, such as storage vessels for the starting materials, heat exchangers for temperature control or, if necessary, evaporation of starting materials, devices for processing the reaction mixture after the reaction of amine with phosgene has taken place.

[0068] The dosing device can be, for example, a dosing pump or a control valve. The optional mixing device can be, for example, a T-piece in the pipeline, a mixing chamber, a static mixer, or a pump, in particular a mixing pump, or a stirred tank. However, the amine streams from the dosing devices can also be mixed in the evaporator. An evaporator is used particularly for liquid amines.

[0069] Preferably, the amine flow device comprises at least one flange connection in at least one of the amine-carrying pipelines, which is designed to accommodate a blanking plate. This makes it possible to reliably prevent the amine flow through the corresponding line by means of the blanking plate or to safely disconnect the corresponding amine line.

[0070] The phosgene stream device, the optional inert material stream device, and the amine stream device are each connected to the phosgenation reactor via at least one feed line. The feed lines can be connected to the phosgenation reactor, for example, via simple pipelines, flange connections, smooth jet nozzles, annular gap nozzles, or a mixing element. The annular gap nozzle can be equipped with two or more, preferably two coaxially arranged channels for the amine stream and the phosgene stream or an inert gas stream, with the amine stream and the phosgene stream only meeting in the phosgenation reactor.Alternatively, particularly in large-scale applications, the amine is added to the phosgenation reactor through an inlet pipe, at the end of which there is a central nozzle and which is held in position by a cover and optionally a holder / rectifier, so that an annular space forms around the inlet pipe in the reactor, with the phosgene entering the annular space via a separate inlet and from there via the rectifier into the phosgenation reactor (see also EP1362847 A2). The phosgenation reactor has a mixing zone where the streams first meet, and a reaction zone where the streams are further reacted. The mixing zone and reaction zone are preferably present in one apparatus. Furthermore, it is preferred that the phosgenation reactor is set up essentially vertically and is preferably connected at the upper end to the phosgene stream device and the amine stream device.

[0071] In addition, the phosgenation plant preferably comprises at least one quench for cooling and at least partially condensing the reaction mixture, which is connected to the phosgenation reactor, preferably at the lower end. The quench is designed in particular for introducing chlorobenzene, o-dichlorobenzene, and / or at least one of the isocyanates produced in the phosgenation plant. In particular, a collecting vessel is assigned to the quench, the collecting vessel preferably being integrated into the quench or separately connected to it.

[0072] Preferably, the amine device, optionally the separate inert material device and / or the phosgene device comprises a heat exchanger for heating the amine mixture, the phosgene and / or optionally the inert material.

[0073] Embodiments:

[0074] The present invention particularly relates to the following embodiments:

[0075] According to a first embodiment, the invention relates to a process for the preparation of isocyanates by phosgenation of the corresponding amines, wherein an amine mixture of 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, characterized in that either

[0076] • the first amine contains at least one ether group; and

[0077] • the second amine is selected from the group comprising or consisting of aminoalkanes having 5 to 15 hydrocarbon atoms which do not contain ether groups; or

[0078] • the first amine contains at least one cyclic ether group; and

[0079] • the second amine contains at least one open-chain ether group and no cyclic ether groups.

[0080] According to a second embodiment, the invention relates to a process according to embodiment 1, characterized in that the first amine containing at least one ether group has a structure of the general formula X-(-R 1 -NH m )n, where

[0081] X for H, NH m or C(R 2 ) P ;

[0082] R 1 for optionally substituted and / or heteroatom-containing, aliphatic, (cyclo)aliphatic or aromatic radicals having preferably up to 10 carbon atoms, where R 1 contains at least one ether group;

[0083] R 2 represents H, optionally substituted and / or heteroatom-containing, aliphatic, (cyclo)aliphatic or aromatic radicals having preferably up to 10 carbon atoms; m represents 1 or 2; n represents 1, 2 or 3; and p represents 1, 2 or 3.

[0084] According to a third embodiment, the invention relates to a process according to embodiment 1 or 2, characterized in that 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 aminoalkanes having 5 to 15 hydrocarbon atoms and / or the second amine containing at least one open-chain ether group and no cyclic ether groups is a diamine.

[0085] According to a fourth embodiment, the invention relates to a process according to one of the preceding embodiments, characterized in that the first amine containing at least one ether group is selected from the group comprising or consisting of (tetrahydrofiran-2,5-diyl)dimethanamine (TEFUDA), 3,6-diamino-hexahydrofiran[3,2-b]firan (e.g.IDDA and / or ISODA) (propane-2,2-diylbis(tetrahydrofiiran-5,2-diyl))dimethanamine, (propane-2,2-diylbis(furan-5,2-diyl))dimethanamine; Di(aminoethyl) ethers, in particular 2,2'-oxybis(ethane-l-amine), l,l'-oxybis(propan-2-amine), 2-(2-aminoethoxy)propan-l-amine, 2,2'-oxybis(propan-l-amine) and 2-(2-aminopropoxy)propan-l-amine; di(aminopropyl) ethers or mixtures thereof and / or the first amine containing at least one cyclic ether group is selected from the group comprising or consisting of (tetrahydrofuran-2,5-diyl)dimethanamine, 3,6-diamino-hexahydrofuro[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 or mixtures thereof.

[0086] According to a fifth embodiment, the invention relates to a process according to one of the preceding embodiments, characterized in that the second amine comprising or consisting of an aminoalkane having 5 to 15 hydrocarbon atoms is selected from the group comprising or consisting of 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 mixtures thereof.

[0087] According to a sixth embodiment, the invention relates to a process according to one of the preceding embodiments, characterized in that the second amine containing at least one open-chain ether group and no cyclic ether groups is selected from the group comprising or consisting of di(aminoethyl) ether, di(aminopropyl) ether, l,8-diamino-l,5,8-trimethyl-3,6-dioxaoctane,

[0088] 1,11-diamino-l, 5,8,11-tetramethylundecane, l,8-diamino-3,6-dioxaoctane, l,10-diamino-4,7-dioxadecane,

[0089] 1,12-diamino-4,9-dioxadodecane, 1, 14-diamino-3, 10-dioxatetradecane, 1, 13-diamino-4,7, 10-trioxatridecanane, l,7-diamino-2,6-dioxa-4-aminomethoxy-heptane, l-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, 1.1 l-diamino-4,8-dioxa-6-(l-amino-5-oxabutyl)undecane, l-Amino-4-oxa-5,5-bis(l-amino-5-oxabutyl)octane or mixtures of that.

[0090] According to a seventh embodiment, the invention relates to a method according to one of the preceding embodiments, characterized in that the mass fraction

[0091] • of the first amine 5.0 to 95.0 wt.%, preferably 10.0 to 80.0 wt.% and

[0092] • of the second amine is 95.0 to 5.0 wt.%, preferably 90.0 to 20.0 wt.%, more preferably 80.0 to 20.0 wt.%, based on the total weight of the amine mixture. According to an eighth embodiment, the invention relates to a process according to any of the preceding embodiments, characterized in that the molar ratio of phosgene to the amino groups of the amines of the amine mixture is > 1:1 to < 5:1, preferably > 1:1 to < 3:1.

[0093] According to a ninth embodiment, the invention relates to a process according to one of the preceding embodiments, characterized in that an inert substance is used in the reaction, wherein the inert substance is selected from the group comprising or consisting of

[0094] • Intergases, in particular nitrogen, argon or mixtures of these;

[0095] • inert solvents, in particular aromatic hydrocarbons, preferably chlorobenzene, o-dichlorobenzene, toluene, xylene or mixtures of these;

[0096] • or mixtures of the aforementioned inert gases and inert solvents.

[0097] According to a tenth embodiment, the invention relates to a method according to one of the preceding embodiments, characterized in that the temperature

[0098] • in the reaction in the condensed phase, on the one hand, between -40°C and the boiling point of the solvent used or the lowest boiling starting material at the pressure set in the reaction and

[0099] • in the gas phase phosgenation is between the boiling point of the reactant with the highest boiling point TI at plant pressure and 600°C, preferably between TI and 550°C, more preferably between TI and 500°C.

[0100] According to an eleventh embodiment, the invention relates to a process according to one of the preceding embodiments, 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, wherein the separation is preferably carried out by means of distillation, in particular thin-film distillation, extraction, crystallization, recrystallization or a combination of these, and the respective isocyanates are obtained separately or as an isocyanate mixture.

[0101] According to a twelfth embodiment, the invention relates to a process according to one of embodiments 1 to 10, 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, wherein the separation is preferably carried out by means of distillation, in particular thin-film distillation, extraction, crystallization, recrystallization or a combination of these, and the respective isocyanates are obtained as an isocyanate mixture

[0102] According to a thirteenth embodiment, the invention relates to a process according to embodiment 11 or 12, characterized in that the content of acidic chlorine compounds in the separated isocyanate(s) or the isocyanate mixture is from 1 to 100 ppm, preferably from 2 to 80 ppm, particularly preferably from 5 to 50 ppm, determined according to the standard ISO 15028:2014.

[0103] According to a fourteenth embodiment, the invention relates to a process according to any of embodiments 11 to 13, characterized in that the content of hydrolyzable chlorine in the separated isocyanate(s) or the isocyanate mixture is from 1 to 500 ppm, preferably from 5 to 100 ppm, determined according to the standard ISO 15028:2014.

[0104] According to a fifteenth embodiment, the invention relates to the use of an amine mixture of at least one first amine and at least one second amine different from the first amine in a process for preparing the corresponding isocyanates by phosgenation according to a process according to one of embodiments 1 to 14 for reducing the content of acidic chlorine compounds and / or the content of hydrolyzable chlorine of the corresponding isocyanates obtained in the preparation.

[0105] According to a sixteenth embodiment, the invention relates to a product obtainable or obtained by a process according to one of embodiments 1 to 13, preferably according to one of embodiments 10 or 12 to 14, preferably directly obtainable or obtained by one of embodiments 1 to 13, preferably according to one of embodiments 10 or 12 to 14.

[0106] According to a seventeenth embodiment, the invention relates to the use of the product according to embodiment 16 and / or the isocyanate or isocyanate mixture obtained or obtainable by a process according to one of embodiments 11 to 14, preferably according to one of embodiments 10 or 12 to 14, as a component for the production of polyurethanes, in particular polyurethane foams, polyurethane coatings and polyurethane adhesives, of pharmaceutical products, in particular active ingredients, and of auxiliaries, in particular auxiliaries for the wet strength finishing of paper and other cellulose products, emulsifiers and thickeners.

[0107] According to an eighteenth embodiment, the invention relates to a phosgenation plant for carrying out the process according to embodiments 1 to 14, comprising or consisting of

[0108] (a) at least one phosgene device for the continuous provision of phosgene, optionally in combination with an inert substance

[0109] (b) where appropriate, an inert material device for providing an inert material,

[0110] (c) at least one amine device for the continuous provision of an amine mixture, optionally in combination with an inert substance

[0111] (d) a phosgenation reactor for mixing the phosgene and the amine mixture and optionally the inert substance and reacting the amine mixture with the phosgene, characterized in that the amine device comprises a first storage container for a first amine and a second storage container for a second amine and a metering device for independently variable adjustment of 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 the amine mixture.

[0112] According to a nineteenth embodiment, the invention relates to a device according to embodiment 18, characterized in that the amine device, optionally the separate inert substance device and / or the phosgene device comprises a heat exchanger for heating the amine mixture, the phosgene and / or optionally the inert substance.

[0113] Examples:

[0114] The examples described below are intended to describe the process and some of the process products according to the invention in more detail without limiting the invention; all percentages refer to the mass unless otherwise stated.

[0115] Mol% data were 1 H-NMR spectroscopy. The measurements were carried out on Bruker DPX 400 and DRX 700 instruments on approximately 5% (*H NMR) and approximately 50% ( 13 C NMR) Samples in dry G,D ( ,. unless otherwise stated, at 400 or 700 MHz ( 1 H NMR) or 100 or 176 MHz ( 13 C NMR). Tetramethylsilane in the solvent served as a reference for the ppm scale 1 H NMR chemical shift 0 ppm. Alternatively, GD^H present in the NMR solvent was used as a reference signal (7.15 ppm, 'H-NMR) or the solvent signal itself (average signal of the 1:1:1 triplet at 128.0 ppm in the 13 C NMR. 15N-NMR chemical shifts were determined indirectly by 'H-^N-HMBC measurements, externally referencing to (liquid) ammonia (0 ppm).

[0116] Dynamic viscosities were determined at 23°C using an MCR 501 rheometer (Pa. Anton Paar) according to DIN EN ISO 3219: 1994-10. Measurements at different shear rates ensured that Newtonian flow behavior could be assumed. Therefore, shear rate data are omitted.

[0117] The NCO content was determined by titration according to DIN EN ISO 10283:2007-11.

[0118] The residual monomer content was determined by gas chromatography according to DIN EN ISO 10283:2007-11 using an internal standard.

[0119] The content of acidic chlorine compounds and the content of hydrolyzable chlorine were determined according to ISO 15028:2014.

[0120] GC-MS was performed using an Agilent GC6890 equipped with a MN 725825.30 Optima-5-MS-Accent capillary column (30 m, 0.25 mm inner diameter, 0.5 pm film thickness) and a 5973 mass spectrometer as the detector, using helium as the transport gas (flow rate 2 mL / min). The column temperature was initially 60 °C (2 min) and then gradually increased to 360 °C at 8 K / min. Electron impact ionization with an ionization energy of 70 eV was used for GC-MS detection. The injector temperature was 250 °C.

[0121] Size exclusion chromatography (SEC) was performed according to DIN 55672-1:2016-03 using tetrahydrofuran as eluent.

[0122] X-ray crystal structure analysis was performed on an Oxford Diffraction Xcalibur equipped with a CCD area detector (Model Ruby), a CUK OSource and osmic mirrors as monochromator at 106–107 K. The program CrysAlis version 1.171.38.43 (Rigaku 2015) was used for data acquisition and reduction. SHELXTL version 6.14 (Bruker AXS, 2003) was used for structure solution.

[0123] The Hazen color number was measured spectrophotometrically according to DIN EN ISO 6271-2:2005-03 using a LICO 400 spectrophotometer from Lange, Germany.

[0124] All reactions were carried out under a nitrogen atmosphere in glass apparatus previously dried in vacuum at 150 - 200°C.

[0125] The diisocyanates used are products of Covestro. All other commercially available chemicals were purchased from Aldrich, D-82018 Taufkirchen, Germany. l,5-Diamino-3-oxapentane (OBDA) was purchased 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 using a method based on a literature report (S. Thiyagarajan, L. Gootjes, W. Vogelzang, J. van Haveren, M. Lutz, DS van Es ChemSusChem 2011, 4, 1823–1829).

[0126] General working regulations

[0127] A Liquid-phase phosgenation (FPP)

[0128] 500 ml of monochlorobenzene (MCB) were placed in a 4-neck flask cooled to -5 °C, equipped with a mechanical stirrer, dropping funnel, internal thermometer, and gas inlet tube. Phosgene (twice the molar amount of the diamine (mixture) to be reacted) was condensed in. The solution of the respective amine (mixture) in MCB was slowly added dropwise while further cooling to -10 to a maximum of 0 °C. After the amine (mixture) had been completely added, 100 ml of MCB was charged to the dropping funnel, and this was also added dropwise to the reaction mixture. While phosgene was passed through the gas inlet tube (approx. 120 g / h), the temperature was then gradually increased until MCB reflux occurred. After boiling point was reached, stirring was continued under reflux while phosgene was passed through (approx. 120 g / h) until a clear solution was formed, but for at least 5 hours.For dephosgenation, stirring was continued at reflux, and dry nitrogen was passed through the gas inlet tube instead of phosgene until phosgene-free status was confirmed using phosgene indicator paper. Further workup is described in the respective examples.

[0129] B Gas-phase phosgenation (GPP)

[0130] In a glass system with a heatable mixing tube measuring 2.5 mm in diameter and 17.5 mm in length, with a downstream condensation stage and a subsequent activated carbon-filled phosgene adsorption tower, phosgene was continuously introduced through a nozzle extending into the mixing tube and preheated in an upstream heat exchanger. A likewise preheated amine mixture, optionally diluted with likewise preheated, dry nitrogen as a diluent, was simultaneously introduced into the reaction chamber through the annular gap between the nozzle and the mixing tube at a metering rate optimized for the specific amine (mixture). A defined pressure was maintained in the mixing tube by applying a vacuum at the end of the condensation stage. The hot reaction mixture, leaving the reaction chamber in gaseous form, was passed through refluxing 1,2-dichlorobenzene in a condensation stage. This resulted in the selective condensation of the diisocyanates formed.The gas mixture passing through the scrubbing stage, consisting essentially of nitrogen, HCl, and excess phosgene, was then freed of phosgene in the adsorption tower, and the condensate was freed of residual dissolved phosgene as described under A. Further processing is described in the respective examples. Example 1 (Comparative Experiments) a) Phosgenation of OBDA in the liquid phase, b) Co-phosgenation of OBDA with MDA according to DE 2249459, and c) Co-phosgenation of IDDA with MDA according to DE 2249459 a).

[0131] 20.83 g (0.2 mol) of OBDA were dissolved in approximately 400 ml of MCB and phosgenated according to general procedure A. The resulting reaction mixture was analyzed by GC / GC-MS. In addition to the solvent, three main components were detected in a ratio of 3:1:47: 2-chloroethyl isocyanate, 2-(2-chloroethoxy)ethyl isocyanate, and OBDI. After separation of low-boiling components (monochlorobenzene and 2-chloroethyl isocyanate) via a 40 cm long packed column (internal diameter approx. 25 mm, packing: #1 Interpack) at reduced pressure, the remaining, largely solvent-free distillation residue was immediately subjected to a trap-to-trap distillation at 0.1 mbar and a bath temperature of 120-180°C. This resulted in 10.5 g of a dark brown, highly viscous distillation residue with 10.8% NCO content and 15.2 g of a light-coloured distillate with 53.0% NCO and 220 / 560 ppm AC / HC content, which according to NMR and GC-MS was approximately 98% OBDI and approximately2% 2-(2-chloroethoxy)ethyl isocyanate (approximately 50% yield of OBDI based on the amine used). After a few days, the previously almost colorless liquid changed color significantly. The product is no longer suitable for problem-free use in typical polyurethane applications. b).

[0132] A mixture of 4.17 g (0.04 mol) of OBDA and 31.78 g of MDA was dissolved in approximately 400 ml of monochlorobenzene and phosgenated according to general procedure A. The resulting reaction mixture was analyzed by GC / GC-MS. In addition to the solvent and aromatic isocyanates, three main components were detected in a ratio of 8.5:1:139: 2-chloroethyl isocyanate, 2-(2-chloroethoxy)ethyl isocyanate, and OBDI. After separation of low boilers (monochlorobenzene and 2-chloroethyl isocyanate) via a 40 cm long packed column, inner diameter approx. 25 mm, filling: #1 Interpack at reduced pressure, the remaining, largely solvent-free distillation residue was then immediately subjected to a “trap-to-trap” distillation at 0.1 mbar and 120 - 180°C bath temperature.This resulted in 29.5 g of a dark brown, highly viscous distillation residue with 26.8% NCO content, which was not further analyzed (mostly polymer MDI), and 12.7 g of a yellowish distillate with 40.0% NCO content, which, according to NMR and GC-MS, consisted of approximately 31.3% OBDI, approximately 0.2% 2-(2-chloroethoxy)ethyl isocyanate, and approximately 68.1% 2-nuclear MDI (3 different isomers, mainly the 4,4'-isomer), along with other unidentified impurities (approximately 64% yield of OBDI based on the OBDA used). The high proportion of decomposition products (2-chloroethyl isocyanate, 2-(2-chloroethoxy)ethyl isocyanate) and the low yield of OBDI demonstrate that the procedure according to DE 2249459 is not successful when using the first amine (amine 1). c).

[0133] A mixture of 5.8 g (0.04 mol) of IDDA and 32.0 g of MDA was dissolved in approximately 1000 ml of monochlorobenzene and phosgenated according to general procedure A. The resulting reaction mixture was largely freed of solvent on a rotary evaporator under reduced pressure and then immediately subjected to trap-to-trap distillation at 0.1 mbar and a bath temperature of 120 - 180°C. This resulted in 20.8 g of a dark brown, highly viscous distillation residue with an NCO content of 28.0%, which, according to GPC and NMR, consisted mainly of polymer MDI, and 27.6 g of a yellowish distillate which contained 1 t. NMR and GC-MS showed that it consisted of approximately 25% IDDI and approximately 75% 2-nuclear MDI (three different isomers, primarily the 4,4'-isomer), along with other unidentified impurities. Distillation of this mixture was unsuccessful. Even after repeated recrystallization from hot isooctane, residues of the aromatic diisocyanate remained in the IDDI.The procedure according to DE 2249459 does not lead to success when using the first amine (amine 1).

[0134] Example 2 (Comparative Experiment) Production of IDDI from IDDA by FPP without the second amine

[0135] 28.5 g (0.2 mol) of IDDA were phosgenated according to general procedure A. The resulting reaction mixture was largely freed of solvent in a rotary evaporator under reduced pressure and then immediately subjected to trap-to-trap distillation at 0.1 mbar and a bath temperature of 120–180°C. This yielded 12.2 g of a dark brown, highly viscous distillation residue and 21.3 g of a light-colored distillate that crystallized after some time. Combined analytical methods (NMR, GC-MS) revealed that it consisted of approximately 98% IDDI (53% yield based on the amine used, AC / HC: 616 / 758 ppm). After several days of storage at room temperature under exclusion of air, the previously almost colorless solid changed color significantly. The product is unsuitable for further problem-free use in typical polyurethane applications.

[0136] Example 3 (according to the invention): CoPg-FPP of IDDA (first amine) and PACM 20 (second amine)

[0137] 33.7 g (0.16 mol) of PACM 20 and 5.8 g (0.04 mol) of IDDA were phosgenated according to general procedure A. The resulting reaction mixture was largely freed of solvent in a rotary evaporator under reduced pressure and then immediately subjected to trap-to-trap distillation at 0.1 mbar and a bath temperature of 120-180°C. This resulted in only 6.2 g of a dark brown, highly viscous distillation residue and 45.7 g of a light-colored distillate, which, after some time, separated crystalline components. According to combined analytical methods (NMR, GC-MS), it consisted of approximately 13% IDDI and 84% H12MDI (78% and 91% yield based on the amines used).Subsequent fractionation yielded 5.6 g of colorless, rapidly crystallizing distillate (boiling point 83°C at 0.1 mbar, melting point 42°C), which showed no tendency to discolor even after weeks of storage at room temperature under exclusion of air and proved to be well-suited for further problem-free use in typical polyurethane applications. Example 4 (Comparative Experiment) Production of ISODI from ISODA by FPP without a "second amine."

[0138] 28.8 g (0.2 mol) of ISODA were phosgenated according to general procedure A. The resulting reaction mixture was largely freed of solvent in a rotary evaporator under reduced pressure and then immediately subjected to trap-to-trap distillation at 0.1 mbar and a bath temperature of 120-180°C. This resulted in 15.1 g of a dark brown, highly viscous distillation residue and 26.0 g (66% yield based on the amine used) of a light-colored distillate, which, according to combined analytical methods (NMR, GC-MS), consisted of approximately 98% ISODI. The titrated NCO content was 42.2%, and the AC / HC values ​​were 904 / 1548 ppm. After a few days, the previously almost colorless distillate changed color significantly and, after several weeks of storage at room temperature in the absence of air, turned dark brown. The product is no longer suitable for trouble-free use in typical polyurethane applications.

[0139] Example 5 (according to the invention): CoPg-FPP of IDDA (first amine) and IPDA (second amine)

[0140] 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 resulting reaction mixture was largely freed of solvent in a rotary evaporator under reduced pressure and then immediately subjected to trap-to-trap distillation at 0.1 mbar and a bath temperature of 120-180°C. This resulted in only 3.6 g of a dark brown, highly viscous distillation residue and 40.6 g of a light-colored distillate, which, according to combined analytical methods (NMR, GC-MS), consisted of approximately 16.7% ISODI and 83.3% IPDI (86% and 95% yield, respectively, based on the amines used). The AC / HC content of this mixture was 42 / 132 ppm.

[0141] Example 6 (Comparative Experiments) Production of H12MDI from PACM 20 by GPP according to general procedure B (experiments a and b) and IPDI from IPDA (experiment c) a) In a gas phase tubular reactor preheated to 350°C, 141 g of PACM 20 (0.67 mol) were reacted with 580 g of phosgene (5.86 mol) at 500 mbar over a period of 2 hours. Both streams were evaporated at the same pressure in a heat exchanger and heated to 350°C. To improve amine evaporation, 60 l / h of nitrogen was passed through the amine evaporator as a carrier gas. Immediately after the start of the reaction, the formation of crusts and deposits at the amine inlet and in the reaction tube was clearly observed. The exact weight after the experiment gave 8 g of solid. b) In a gas phase tubular reactor preheated to 450°C, 139 g of PACM 20 (0.66 mol) were reacted with 581 g of phosgene (5.87 mol) at 500 mbar within 2 hours.Both material streams were evaporated at the same pressure in a heat exchanger and heated to 450°C. To improve amine evaporation, 60 l / h of nitrogen was passed through the amine evaporator as a carrier gas stream. Compared to Example 6a, significantly fewer crusts and deposits were formed. After the experiment, only a very thin wall coating could be detected in the reactor, which was determined to be 1.3 g by reweighing. c) In a gas-phase tubular reactor preheated to 350°C, 170 g of IPDA (1.0 mol) were reacted with 622 g of phosgene (6.29 mol) at 500 mbar over a period of 2 hours. Both material streams were evaporated at 500 mbar in a heat exchanger and heated to 350°C. To improve amine evaporation, 30 l / h of nitrogen was passed through the amine evaporator. After the start of the reaction, only a slight formation of crusts and deposits was observed at the amine inlet and in the reaction tube, which were determined to be 0.5 g after the experiment.

[0142] The reaction mixtures obtained under a and b were analyzed by 'H-NMR, revealing that, in addition to the solvent and H12MDI, they contained significant amounts of an olefin, which was identified by GC-MS as cyclohexenylmethylcyclohexyl isocyanate (several isomers). In example 6b, the proportion of this undesired by-product, relative to the target compound H12MDI, was significantly lower than in 6a: 67:1 versus 4:1 (mass of H12MDI: mass of olefin).

[0143] After solvent removal and subsequent trap-to-trap distillation as described in Examples 2-5, a) yielded 6.15 g of a dark brown, viscous distillation residue and 140.4 g of a light-colored distillate. Subsequent fractionation through a 40 cm long, vacuum-jacketed Vigreux column with an internal diameter of approximately 25 mm yielded 123.6 g of a constant-boiling, colorless main fraction with only 30.3% NCO content (<70% yield of H12MDI based on PACM 20 used). b) yielded 2.8 g of residue and 163 g of final distillate with 31.8% NCO content (93% yield of H12MDI based on PACM 20 used).

[0144] Example 7 (according to the invention): CoPg-GPP of TEFUDA (first amine or amine 1) and PACM 20 (second amine or amine 2) by GPP according to general procedure B

[0145] Based on Example 6b, mixtures of TEFUDA (amine 1) and PACM 20 (amine 2) were phosgenated according to general procedure B. At the start of the experiment, pure amine 2 (approximately 0.335 mol / h) with a molar phosgene excess of approximately 250% was added. After 30 minutes of the experiment, amine 1 was added so that an amine mixture consisting of 25 mol% amine 1 and 75 mol% amine 2 was added. In subsequent experiments, the concentration of amine 1 was further increased, resulting in amine mixtures containing 50 mol% amine 1 / 50 mol% amine 2 and 75 mol% amine 1 / 25 mol% amine 2. A total of 782.6 g (6 mol) of TEFUDA and 1431.1 g (6.8 mol) of PACM 20 were processed. The dosed amounts, excess phosgene used, and run times can be found in the following table.

[0146] The dephosgenated raw materials were analyzed by 'H-NMR spectroscopy and then combined. Regarding the H12MDI:olefin ratio, it was found that the proportion of the undesired compound was significantly reduced again in all runs 7-1 to 7-7 compared to the better comparative example 6b, averaging only 146:1. No significant differences in this ratio were observed in runs 7-1 to 7-7.

[0147] Workup as described in Example 6, with the difference that a more efficient column was used for the final separation of TEFUDI and H12MDI (40 cm packed column, internal diameter approx. 25 mm, packing: #1 Interpack). This yielded only 53.9 g of a dark brown, highly viscous distillation residue and 980.5 g of TEFUDI and 1674.2 g of H12MDI, each as light-colored liquids, which, according to combined analytical methods (NMR, GC-MS), consisted of >99% TEFUDI and H12MDI (isomer mixture) (90% and 94% yield based on the amines used). The AC / HC content was 35 / 318 ppm (TEFUDI) and 29 / 87 ppm (H12MDI). No discoloration was observed even after weeks of storage under exclusion of air.

[0148] Example 8 (according to the invention): CoPg-GPP of ISODA (first amine or amine 1) and PACM 20 (second amine or amine 2) by GPP according to general procedure B.

[0149] Following the procedure from Example 7, mixtures of ISODA (amine 1) and PACM 20 (amine 2) were phosgenated in a gas-phase phosgenation apparatus. In Experiment 8-1, pure amine 2 (~0.5 mol / h) was metered in at approximately 250% molar phosgene excess at the start of the experiment. After 30 minutes of the experiment, amine 1 was added so that an amine mixture consisting of 25 mol% amine 1 and 75 mol% amine 2 was metered in. This stepwise increase of 25 mol% was carried out twice after a further 30 minutes, so that 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, which was then kept constant until the end of the experiment after a total runtime of 6.25 hours. In the subsequent experiments, after the first phase with pure amine 2, an amine mixture consisting of 50 mol% amine 1 and 50 mol% amine 2 was immediately dosed, which was maintained until the end of the experiment.In addition, the phosgene excess was reduced from experiment to experiment, which tended to result in lower reactor loading. The amounts added in the individual experiments, the phosgene excesses used, and the run times can be found in the table below. A total of 1353.9 g (9.39 mol) of ISODA and 915.0 g (4.35 mol) of PACM 20 were processed.

[0150] The dephosgenated raw materials were analyzed by 'H-NMR spectroscopy and then combined. Regarding the H12MDI:olefin ratio, it was found that the proportion of the undesired compound was again significantly reduced compared to the better comparative example 6b, averaging only 127:1. Again, no significant differences were observed regarding this ratio in test runs 8-1 to 8-5.

[0151] Workup as described in Example 7 yielded only 60.1 g of a dark brown, highly viscous distillation residue, as well as 1795.8 g of ISODI and 993.1 g of H12MDI as light-colored liquids, which, according to combined analytical methods (NMR, GC-MS), consisted of >99% ISODI and H12MDI (isomer mixture) (97.5% and 87.0% yield based on the amines used). The AC / HC content was 27 / 178 ppm (ISODI) and 15 / 152 ppm (H12MDI), respectively. No discoloration was observed in either of the products obtained according to the invention, even after weeks of storage at room temperature under exclusion of air.

[0152] Example 9 a) Two comparative experiments GPP of OBDA b) according to the invention: CoPg-GPP of OBDA (first amine) and IPDA (second amine) by GPP according to general procedure B a)

[0153] In two separate experiments, OBDA and phosgene were reacted at 500 mbar in a gas-phase tubular reactor preheated to 350°C. Both streams were evaporated in a heat exchanger at 500 mbar and heated to 350°C. To improve 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) were reacted with 1376 g of phosgene (13.9 mol) within 3.8 hours. In the second comparative experiment, 312 g of OBDA (3.0 mol) and 1219 g of phosgene (12.3 mol) were added within 3.5 hours, with the reactor loading determined to be 9 g after the experiment.

[0154] Workup as described in Example 6 yielded 185 g of a dark brown, highly viscous distillation residue and 723.0 g of OBDI as a light-colored liquid, which, according to combined analytical methods (NMR, GC-MS), consisted of >98% OBDI (76% yield based on the amine used). The AC / HC content was 90 / 793 ppm. Over the course of several weeks of storage at room temperature in the absence of air, the product changed color significantly. The color number increased from an initial 8 Apha immediately after distillation to 520 Apha after 3 weeks. b)

[0155] Based on 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 a period of 6 hours and reacted with 2223 g of phosgene (22.47 mol) at a system pressure of 500 mbar. Both streams were evaporated in a heat exchanger at 500 mbar and heated to 350°C. To improve amine evaporation, 30 l / h of nitrogen 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 solids formation at the amine inlet and in the reaction tube was determined to be 4 g after the experiment.

[0156] Workup as described in Example 6 yielded only 12 g of a dark brown, highly viscous distillation residue, 169 g of OBDI, and 442 g of IPDI as light-colored liquids, which, according to combined analytical methods (NMR, GC-MS), consisted of >99% OBDI and IPDI (isomer mixture) (95% yield in each case based on the amines used). The AC / HC content was 19 / 114 ppm (OBDI) and 12 / 212 ppm (IPDI), respectively. No discoloration was observed in either of the products obtained according to the invention, even after weeks of storage at room temperature in the absence of air.

[0157] Example 10 (according to the invention): CoPg-GPP of ISODA (first amine) and OBDA (second amine)

[0158] Initially, 42.2 g of OBDA (0.4 mol) and 152 g of phosgene (1.54 mol) were metered into a gas-phase tubular reactor preheated to 350°C over a period of 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 a period of 3 hours and reacted with 933 g of phosgene (9.43 mol) at a plant pressure of 500 mbar. Both streams were evaporated in a heat exchanger at 500 mbar and heated to 350°C. To improve 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 dephosgenated by nitrogen stripping. The solid formation at the amine inlet and in the reaction tube determined after the experiment was 8.3 g.Workup as described in Example 6 yielded only 16.6 g of a dark brown, highly viscous distillation residue, 49.8 g of ISODI, and 199.9 g of OBDI as light-colored liquids, which, according to combined analytical methods (NMR, GC-MS), consisted of >99% ISODI and OBDI, respectively (68% and 84% yield based on the amines used). No discoloration was observed in either of the products obtained according to the invention, even after weeks of storage at room temperature under the exclusion of air.

[0159] Several attempts to convert TEFUDA, IDDA, and ISODA without any "amine 2" using GPP failed after a maximum of 60 minutes of operation. Stubborn deposits formed, and the pressure increase in the plant necessitated shutting down after an unacceptably short runtime. The resulting ISODI, which was produced in very poor yield, was of completely unacceptable quality and extremely difficult to clean.

Claims

Patent claims 1. A process for the preparation of isocyanates by phosgenation of the corresponding amines, wherein an amine mixture of 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, characterized in that either • the first amine contains at least one ether group; and • the second amine is selected from the group comprising or consisting of aminoalkanes with 5 to 15 hydrocarbon atoms, which do not contain ether groups; or • the first amine contains at least one cyclic ether group; and • the second amine contains at least one open-chain ether group and no cyclic ether groups.

2. Method according to claim 1, characterized in that the first amine containing at least one ether group has a structure of the general formula X-(-R1 -NH m )n exhibits X for H, NH m or C(R 2 ) p ; R 1 for, optionally substituted and / or heteroatom-containing, aliphatic, (cyclo)aliphatic or aromatic residues with preferably up to 10 carbon atoms, wherein R 1 contains at least one ether group; R 2 for H, optionally substituted and / or heteroatom-containing, aliphatic, (cyclo)aliphatic or aromatic residues with preferably up to 10 carbon atoms; m for 1 or 2; n for 1, 2 or 3; and p for 1, 2 or 3.

3. Method according to claim 1 or 2, characterized in that 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 aminoalkanes with 5 to 15 hydrocarbon atoms and / or the second amine containing at least one open-chain ether group and no cyclic ether groups is a diamine. A method according to one of the preceding claims, characterized in that the first amine containing at least one ether group is selected from the group comprising or consisting of (tetrahydrofuran-2,5-diyl)dimethanamine, 3,6-diamino-hexahydrofuro[3,2-b]furan, 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(ethan-l-amine), l,l'-oxybis(propan-2-amine), 2-(2-aminoethoxy)propan-l-amine, 2,2'-oxybis(propan-l-amine) and 2-(2-aminopropoxy)propan-l-amine;Di(aminopropyl)ether or mixtures thereof and / or the first amine containing at least one cyclic ether group is selected from the group comprising or consisting of (tetrahydrofuran-2,5-diyl)dimethanamine, 3,6-diamino-hexahydrofuro[3,2-b]furan, 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 mixtures thereof. Method according to one of the preceding claims, characterized in that the; The aminoalkane comprising or consisting of a second amine comprising or consisting of 5 to 15 hydrocarbon atoms is selected from the group comprising or consisting of 1,5-diaminopentane; 1,6-diaminohexane; l-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 mixtures thereof.A method according to one of the preceding claims, characterized in that the second amine, containing at least one open-chain ether group and no cyclic ether groups, is selected from the group comprising or 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-trioxatridecanane. l,7-diamino-2,6-dioxa-4-aminomethoxy-heptane, l-amino-2-oxa-3,3-bis(aminomethoxy)hexane, l,9-diamino-3,7-dioxa-5-(l-amino-2-ethoxy)-nonane, l-amino-3-oxa-4,4-bis(l-amino-2-ethoxy)heptane, 1.1 l-diamino-4,8-dioxa-6-(l-amino-5-oxabutyl)undecane, l-amino-4-oxa-5,5-bis(l-amino-5-oxabutyl)octane or mixtures thereof.

7. Method according to one of the preceding claims, characterized in that the mass fraction • of the first amine 5.0 to 95.0 wt.%, preferably 10.0 to 80.0 wt.% and • of the second amine 95.0 to 5.0 wt.%, preferably 90.0 to 20.0 wt.%, more preferably 80.0 to 20.0 wt.%, based on the total weight of the amine mixture, and / or the molar ratio of phosgene to the amino groups of the amines of the amine mixture is > 1 :1 to < 5 : 1, preferably > 1 :1 to < 3 :

1.

8. A method according to one of the preceding claims, characterized in that an inert substance is used in the reaction, wherein the inert substance is selected from the group comprising or consisting of • Intergases, especially nitrogen, argon or mixtures thereof; • inert solvents, especially aromatic hydrocarbons, preferably chlorobenzene, o-dichlorobenzene, toluene, xylene or mixtures thereof; • or mixtures of the aforementioned inert gases and inert solvents.

9. A method according to one of the preceding claims, 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, wherein the separation is preferably carried out by distillation, in particular thin-film distillation, extraction, crystallization, recrystallization or a combination thereof, and the respective isocyanates are obtained separately or as an isocyanate mixture.

10. A method according to any one of claims 1 to 8, 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, wherein the separation is preferably carried out by distillation, in particular thin-film distillation, extraction, crystallization, recrystallization or a These are combined and the respective isocyanates are obtained as an isocyanate mixture.

11. A method according to claim 9 or 10, characterized in that the content of acidic chlorine compounds in the separated isocyanate(s) or the isocyanate mixture is from 1 to 100 ppm, preferably from 2 to 80 ppm, particularly preferably from 5 to 50 ppm, determined according to ISO 15028:2014, and / or the content of hydrolyzable chlorine in the separated isocyanate(s) or the isocyanate mixture is from 1 to 500 ppm, preferably from 5 to 100 ppm, determined according to ISO 15028:2014.

12. Use of an amine mixture of at least one first amine and at least one second amine different from the first amine in a process for the preparation of the corresponding isocyanates by phosgenation according to a process according to one of claims 1 to 11 for reducing the content of acidic chlorine compounds and / or the content of hydrolyzable chlorine of the corresponding isocyanates obtained in the preparation.

13. Product obtainable or obtained by a method according to any one of claims 1 to 8, 10 or 11, preferably directly obtainable or obtained by a method according to any one of claims 1 to 8, 10 or 11.

14. Use of the product according to claim 13 and / or the isocyanate or isocyanate mixture obtained or obtainable by a process according to claim 10 or 11 as a component for the production of polyurethanes, in particular polyurethane foams, polyurethane coatings and polyurethane adhesives, pharmaceutical products, in particular active ingredients, and excipients, in particular excipients for the wet strength treatment of paper and other cellulose products, emulsifiers and thickeners.

15. Phosgenation plant for carrying out the process according to claims 1 to 11, comprising or consisting of (a) at least one phosgene device for the continuous provision of phosgene, optionally in combination with an inert substance (b) where appropriate, an inert material device for providing an inert material, (c) at least one amine device for the continuous supply of an amine mixture, possibly in combination with an inert substance (d) a phosgenation reactor for mixing the phosgene and the amine mixture and optionally the inert substance and reacting the amine mixture with the phosgene, characterized in that the amine device comprises a first storage container for a first amine and a second storage container for a second amine, as well as a metering device for independently variable adjustment of 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 the amine mixture.

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