DE102015219729A1 - Process for the hydrogenation of dihydroxydiphenylalkanes - Google Patents

Abstract

Process for the hydrogenation of dihydroxydiphenylalkanes of the formula Iworin R 1, R 1 ', R 3 and R 3' independently of one another represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 C atoms and R 2 and R 2 'independently of one another are an H atom or a C 1 - to C5-alkyl group, to the corresponding Dihydroxydicyclohexylalkanen, characterized in that a supported catalyst is used as the hydrogenation catalyst, the zirconium dioxide as a carrier and as an active metal ruthenium.

Description

worin R¹, R^1‘, R³ und R^3‘ unabhängig voneinander für ein Wasserstoffatom oder eine aliphatische Kohlenwasserstoffgruppe mit 1 bis 10 C-Atomen stehen und R² und R^2‘ unabhängig voneinander für ein H-Atom oder für eine C1- bis C5-Alkylgruppe steht, zu den entsprechenden Dihydroxydicyclohexylalkanen, welches dadurch gekennzeichnet ist, dass als Hydrierkatalysator ein Trägerkatalysator verwendet wird, der Zirkondioxid als Träger und als aktives Metall Ruthenium enthält.The present invention relates to a process for the hydrogenation of dihydroxydiphenylalkanes of the formula I.

in which R ¹ , R ^{1 '} , R ³ and R ^3' independently of one another represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 C atoms and R ² and R ^{2 '} independently of one another represent an H atom or a C 1 to C5-alkyl group, to the corresponding Dihydroxydicyclohexylalkanen, which is characterized in that a supported catalyst is used as the hydrogenation catalyst, the zirconium dioxide as a carrier and as an active metal ruthenium.

Dihydroxydicyclohexylalkanes are e.g. as a crosslinker or as a starting material for epoxy resins of importance.

US 1593080 discloses, for example, the hydrogenation of di (3-methyl-4-hydroxylphenyl) -2-propane (bisphenol C) to di (3-methyl-4-hydroxycyclohexyl) -2-propane (hydrogenated bisphenol C) on a nickel-containing catalyst. Nothing is disclosed about the purity of the product and the nature of the nickel catalyst.

US 5942645 discloses the hydrogenation of aromatic compounds to which at least one hydroxyl group is attached by means of a ruthenium-containing supported catalyst. In the examples, only alumina is used as the carrier.

US 5874622 discloses the hydrogenation of aromatic compounds to which at least one hydroxyl group is attached by means of a ruthenium-containing supported catalyst prepared by means of an organic polymer. In the examples again alumina alone is used as carrier.

In WO2011 / 082991 describes the hydrogenation of aromatics with the aid of a supported catalyst with silica as support. Active metals are selected from the group ruthenium, rhodium, palladium and platinum.

DE-A 19622705 discloses the hydrogenation of aromatic compounds containing at least one hydroxyl group by means of a ruthenium-containing supported catalyst. Ruthenium is applied to the support during hydrogenation (in situ).

EP-A 813906 also describes a hydrogenation of aromatics in the presence of a supported catalyst with at least one metal of the I, VII or VIII subgroup of the periodic table as the active metal.

In the hitherto known processes for the hydrogenation of dihydroxydiphenylalkanes, high pressures and high temperatures are frequently necessary. Also, the sales and selectivities are to be further improved. By-products, especially low-boiling impurities, must be removed consuming.

The object of the present invention was therefore a process for the hydrogenation of dihydroxydiphenylalkanes, in particular bisphenol C, which can be carried out simply and economically, low pressures and temperatures, and wherein the Dihydroxydicyclohexylalkane, in particular hydrogenated bisphenol C (di (3-methyl-4-hydroxycyclohexyl ) -2-propane) are available with high conversions and with high selectivity.

Accordingly, the method defined above was found.

To the dihydroxydiphenylalkanes

In formula I, R ¹ , R ^{1 '} , R ³ and R ^3' independently of one another represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 C atoms. The aliphatic hydrocarbon group may be, for example, linear or branched alkyl groups or cycloalkyl groups, which are optionally substituted by linear or branched alkyl groups act.

Preferably, R ¹ , R ^{1 '} , R ³ and R ^3' independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 6 carbon atoms, for example a linear or branched alkyl group having 1 to 6 carbon atoms, for. For example, a methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl or tertiary-butyl group or a cyclohexyl group, in particular, in the hydrocarbon group is a C1 to C4 - Alkyl group, preferably a methyl group.

In a preferred embodiment, R ¹ and R ^{1 'are} identical, as are R ³ and R ^3' .

Particularly preferred dihydroxydiphenyalkanes of the formula I are those in which R ¹ and R ^{1 'have} the above meanings and preferred meanings, but both R ³ and R ^{3' in} principle represent a hydrogen atom.

In formula I, R ² and R ^{2 '} independently of one another are an H atom or a C 1 - to C 5 -alkyl group, in particular an H atom, a methyl or an ethyl group. In a preferred embodiment, R ² and R ^{2 'are} identical.

Particularly preferably, R ² and R ^{2 'are} identical and stand for a methyl group or an ethyl group, in particular a methyl group.

As a particularly preferred compound of the formula I is bisphenol C (di (3-methyl-4-hydroxylphenyl) -2-propane (R ¹ , R ^{1 '} , R ² and R ^2' = methyl, R ³ and R ^{3 '} = H ) called.

To the supported catalyst

The supported catalyst contains zirconium dioxide as a carrier and ruthenium as the active metal.

In addition to ruthenium, the supported catalyst may contain further active metals. Consider, for example, Metals of Groups IVb, Vb, VIb, VIIb, VIIIb, Ib or IIb of the Periodic Table.

Specifically its called nickel, palladium, platinum, cobalt, rhodium, iridium, copper, manganese or tin.

Preferred further active metals are metals of VIII. Subgroup of the Periodic Table, in particular rhodium, palladium and platinum.

The supported catalyst contains the active metals either in elemental form or in the form of compounds, e.g. B. oxides. The term metal therefore includes below elementary metals or metals, such as those in chemical bonds, be it in ionic form or covalently bonded form. All weights of the active metals, however, refer only to the metals as such and, in the case of the metal compounds, do not include the other constituents of the compounds. When using the active metals in the form of their oxides or optionally also other compounds is generally carried out at higher temperatures, in particular in the presence of hydrogen, a reduction of the oxides to the metals. This can be done at the beginning of the implementation or in advance in a separate step.

In a preferred embodiment, it is at least 30 wt.%, In particular at least 50 wt.%, Particularly preferably at least 70 wt.% And most preferably at 90 wt.% Of the active metals of the supported catalyst to ruthenium. In a particular embodiment, the supported catalyst contains only ruthenium as the active metal.

The supported catalyst contains active metals, or exclusively ruthenium in the particularly preferred embodiment, preferably in a total amount of 0.01 to 20 weight percent, preferably 0.05 to 15 weight percent, particularly preferably 0.1 to 10 weight percent, based on the total weight of supported catalyst.

The preparation of the supported catalyst is known.

The carrier zirconia may e.g. in the form of extrudates, spheres or tablets, for example with diameters of 1-10 mm, or preferably as a powder. On the support, the active metals z. B. be applied in the form of metal salt solutions. The support can be brought into a desired shape before or after the application of the active metals.

Preferably, the supported catalyst is used as a powder.

The supported catalyst is preferably dried at temperatures of up to 300 ° C and then calcined at temperatures up to 600 ° C or directly calcined at up to 600 ° C.

Preferably, the supported catalyst is activated with hydrogen at a temperature of, for example, 100-350 ° C prior to its use. This can be done after introducing the catalyst into the reactor, for example before or after the beginning of the hydrogenation of the Dihydroxydiphenylalkane.

Frequently, the supported catalyst is activated before introduction into the reactor and then passivated with oxygen on the surface so that it can still be stored or is safe to handle. Only in the reactor is then the final activation.

To the procedure

For the hydrogenation of the dihydroxydiphenylalkanes, hydrogen or compounds which release hydrogen can be used as the hydrogenating agent.

Preferably, hydrogen is used as the hydrogenating agent. As hydrogen, e.g. technically pure hydrogen are used, wherein "technically pure" a content of hydrogen of at least 99 weight percent, in particular at least 99.5 weight percent is understood.

Hydrogen can also be used in mixture with other gases. In consideration are gas mixtures of hydrogen and inert gases such as helium, argon, carbon dioxide, nitrogen or neon.

Preferably, hydrogen is used in a technically pure form.

The dihydroxydiphenylalkanes are preferably present in the hydrogenation in liquid form, be it as a melt or as a solution in a solvent.

Preferably, the Dihydroxydiphenylalkane are present as a solution in a solvent.

Suitable solvents are, for example, alcohols or ethers, in particular aliphatic alcohols or ethers. The hydrogenation is therefore preferably carried out in the presence of an alcohol or ether as solvent.

Suitable alcohols are, for example, methanol, ethanol, propanol, n-butanol, isopropanol, isobutanol, tert-butanol, suitable ethers, for example dioxane, tetrahydrofuran, diethyl ether, methyl tert-butyl ether, glycol dimethyl ether (diglyme), glycol dipropyl ether (proglyme) and mixtures thereof. As solvents, the products of the hydrogenation, ie the resulting dihydroxydicyclohexylalkanes and / or low-boiling by-products such as hydroxydicyclohexylalkanes can also be used in a continuous procedure (. A particularly preferred alcohol is n-butanol.

Suitable ethers are, in particular, cyclic ethers, very particularly preferably 1,4-dioxane.

The concentration of the dihydroxydiphenylalkane in the solution is, for example, 1 to 80% by weight, preferably 5 to 40% by weight, and more preferably 10 to 30% by weight of dihydroxydiphenylalkane, based on the total weight of the solution.

The hydrogenation is preferably carried out at a temperature of 20 to 300 ° C, preferably from 50 to 200 ° C.

In a particularly preferred embodiment, the temperature is at most 200 ° C, very particularly preferably at most 180 ° C. A particularly preferred Temperaurbereich is therefore 80 to 180 ° C and 80 to 160 ° C. A most preferred Temperaurbereich is 100 to 160 ° C.

The hydrogenation is preferably carried out at a pressure of 20 to 300 bar, in particular at a pressure of 30 to 200 bar and particularly preferably at a pressure of 50 to 180 bar.

The pressure is adjusted in particular by supplying appropriate amounts of hydrogen or the gas mixture of hydrogen and inert gas (see above).

The hydrogenation process can be carried out continuously or discontinuously (batch process).

In the batchwise operation, the hydrogenation can be carried out, for example, in a stirred tank or stirred autoclave, a loop reactor, a jet loop reactor, a bubble column or a fixed bed reactor with pumped circulation. The discontinuous hydrogenation is preferably carried out in a stirred tank or stirred autoclave. In the batchwise procedure, the dihydroxydiphenylalkane and the catalyst are generally initially introduced completely into the reactor.

The catalyst may be used in the batch process in the reactor e.g. be introduced as a fixed bed or in another form. In a preferred embodiment, the catalyst may be suspended in the dihydroxydiphenylalkane or its solution and the resulting suspension filled into the reactor.

In the continuous operation, the hydrogenation is e.g. in a continuously operated stirred tank reactor, a continuously operated loop separator, a continuously operated jet loop reactor, a continuously operated bubble column or a continuously operated fixed bed reactor with pumped circulation or stirred tank cascade. In the continuous implementation, the Dihydroxydiphenylalkan or its solution is continuously fed and the resulting product mixture containing the corresponding Dihydroxydihexylalkan removed. In the continuous procedure, the catalyst is e.g. as a fixed bed in the reactor and is renewed and / or regenerated only when needed.

The process is preferably carried out in a stirred tank reactor operated batchwise.

The product mixture obtained can be worked up further. The catalyst can be separated from the product mixture in batch processes, for example by a solid-liquid separation, such as filtration, sedimentation or centrifugation. Thereafter, solvents and optionally by-products such as incompletely hydrogenated Dihydroxydiphenylalkane and residual Dihydroxydiphenylalkane z. B. separated by distillation and / or purified. Dihydroxydiphenylalkanes can be recycled to the reaction or hydrogenated again in the batch process.

The process generally hydrogenates at least 90% by weight, more preferably at least 98% by weight, and most preferably at least 99% by weight of the dihydroxydiphenylalkanes. There is generally complete hydrogenation of the dihydroxydiphenylalkanes to the corresponding dihydoxydicyclohexylalkanes. The proportion of fully hydrogenated compounds, that is the dihydroxydicyclohexylalkanes, is at least 90% by weight, more preferably at least 95% by weight, very preferably at least 96.5% by weight, based on all the hydrogenated compounds obtained.

The dihydroxydicyclohexylalkanes obtained can be used, for example, as synthesis building blocks for the preparation of surfactants, pharmaceutical and plant protection agents, stabilizers, light stabilizers, polymers, polycarbonates, polyisocyanates, hardeners for epoxy resins, polyurethanes, plasticizers, corrosion inhibitors, synthetic resins, ion exchangers, textile auxiliaries, dyes, vulcanization accelerators and / or emulsifiers.

The process gives dihydroxydicyclohexylalkanes with high conversion and high selectivity. The process is very cost effective and economical. High temperatures are not required in the process. The high conversion and high selectivity are already achieved at temperatures below 150 ° C.

Examples

The conversion and the selectivity were determined by GC analysis (GC column: Optima OV1701, length = 60 m, inner diameter = 0.32 mm, film thickness = 0.25 μm, injection temperature 300 ° C., detection temperature 300 ° C.) and Area% indicated.

Comparative Example 1

Bisphenol C (20 g) was dissolved in n-butanol (80 g) and placed in a 300 mL autoclave. Raney-Ni (1 g) was added. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of 7% was obtained with a selectivity of hydrogenated bisphenol C (di (3-methyl-4-hydroxycyclohexyl) -2-propane) of 59%.

Comparative Example 2

Bisphenol C (20 g) was dissolved in n-butanol (80 g) and placed in a 300 mL autoclave. A ruthenium catalyst (1 g, 0.5% Ru on Al ₂ O ₃ ) was added. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of 4% with a hydrogenated bisphenol C selectivity of 49% was obtained.

Comparative Example 3

Bisphenol C (20 g) was dissolved in n-butanol (80 g) and placed in a 300 mL autoclave. A ruthenium catalyst (1 g, 0.3% Ru on SiO ₂ ) was added. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. There was no sales received.

Comparative Example 4

Bisphenol C (20 g) was dissolved in n-butanol (80 g) and placed in a 300 mL autoclave. A ruthenium catalyst (1 g, 0.3% Ru on SiO ₂ ) was added. The autoclave was closed and pressurized to 150 bar hydrogen pressure, heated to 160 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. There was no sales received.

Comparative Example 5

Bisphenol C (20 g) was dissolved in 1,4-dioxane (80 g) and placed in a 300 mL autoclave. A ruthenium catalyst (1 g, 5% Ru 1% Fe on carbon) was added. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of 1.5% was obtained with a hydrogenated bisphenol C selectivity of 84%.

Comparative Example 6

Bisphenol C (20 g) was dissolved in n-butanol (80 g) and placed in a 300 mL autoclave. A ruthenium catalyst (17 g, 0.3% Ru on SiO ₂ ) was added. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of 74% with a hydrogenated bisphenol C selectivity of 74% was obtained.

example 1

Bisphenol C (20 g) was dissolved in n-butanol (80 g) and placed in a 300 mL autoclave. There was a ruthenium catalyst (1 g, 5% Ru on ZrO ₂₎ was added thereto. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of> 99% was obtained with a hydrogenated bisphenol C selectivity of 97.0%.

Example 2

Bisphenol C (20 g) was dissolved in n-butanol (80 g), water was added (0.4 g) and the mixture was placed in a 300 mL autoclave. A ruthenium catalyst (1 g, 5% Ru on ZrO ₂ ) was added. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of> 99% with a hydrogenated bisphenol C selectivity of 97.3% was obtained.

Example 3

Bisphenol C (20 g) was dissolved in 1,4-dioxane (80 g) and placed in a 300 mL autoclave. A ruthenium catalyst (1 g, 5% Ru on ZrO ₂ ) was added. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of> 99% was obtained with a hydrogenated bisphenol C selectivity of 99%.

Example 4

Bisphenol C (1 kg) was dissolved in n-butanol (4 kg) and placed in a 9 L autoclave. A ruthenium catalyst (50 g, 5% Ru on ZrO ₂ ) was added. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of> 99% was obtained with a hydrogenated bisphenol C selectivity of 99%.

Example 5

Bisphenol C (20 g) was dissolved in n-butanol (80 g) and placed in a 300 mL autoclave. A ruthenium catalyst (1 g, 5% Ru on ZrO ₂ ) was added. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 150 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of> 99% with a selectivity of 97.0% was obtained.

Example 6

Bisphenol C (20 g) was dissolved in n-butanol (80 g) and placed in a 300 mL autoclave. A ruthenium catalyst (1 g, 5% Ru on ZrO ₂ ) was added. The autoclave was closed and pressurized with 150 bar hydrogen pressure, heated to 200 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of> 99% was obtained at a selectivity of 92.1%.

Example 7

Bisphenol C (20 g) was dissolved in n-butanol (80 g) and placed in a 300 mL autoclave. A ruthenium catalyst (1 g, 5% Ru on ZrO ₂ ) was added. The autoclave was closed and subjected to 80 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of> 99% with a selectivity of 99.8% was obtained.

Example 8

Bisphenol A (20 g) was dissolved in n-butanol (80 g) and placed in a 300 mL autoclave. There was a ruthenium catalyst (1 g, 5% Ru on ZrO ₂₎ was added thereto. The autoclave was closed and subjected to 150 bar hydrogen pressure, heated to 120 ° C and stirred for 12 h. Subsequently, a sample of the reaction mixture was analyzed by GC. A conversion of> 99% with a selectivity of 97.6% was obtained.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 1593080 [0003]
• US 5942645 [0004]
• US 5874622 [0005]
• WO 2011/082991 [0006]
• DE19622705A [0007]
• EP 813906 A [0008]

Claims (7)

Process for the hydrogenation of dihydroxydiphenylalkanes of the formula I

in which R ¹ , R ^{1 '} , R ³ and R ^3' independently of one another represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 C atoms and R ² and R ^{2 '} independently of one another denote an H atom or a C 1 to C5-alkyl group, to the corresponding Dihydroxydicyclohexylalkanen, characterized in that a supported catalyst is used as the hydrogenation catalyst, the zirconium dioxide as a carrier and as an active metal ruthenium. Process according to claim 1, characterized in that R ² and R ^{2 'represent} a methyl group. A process according to claim 1, characterized in that the dihydroxydiphenylalkane of the formula I is bisphenol C. Method according to one of claims 1 to 3, characterized in that the hydrogenation is carried out at a temperature of at most 200 ° C. Method according to one of claims 1 to 4, characterized in that the hydrogenation is carried out at a temperature of 80 to 180 ° C. Method according to one of claims 1 to 5, characterized in that the hydrogenation is carried out at a pressure of 20 to 300 bar. Process according to any one of Claims 1 to 6, characterized in that the hydrogenation is carried out in the presence of an alcohol or ether as solvent.