SK75493A3 - Method of preparation of n-alkyl-n'-phenyl-p-phenylendiamine and/or n-cyclohexyl-n'-phenyl-p-phenylendiamine - Google Patents

Abstract

There is disclosed a preparation of the general formula (I) compounds in which R is an C3-C18 alkyl group or cyclohexyl based on at least one primary intermediate selected from the group containing 4-nitrodiphenylamine, 4-nitrozodiphenylamine, salts of 4-nitrozodiphenylamine which is subjected to an alk. reduction to afford 4-aminodiphenylamine where it is further subjected to an alk. reduction with C3-C18 carbonyl compounds or is subjected to an alk. condensation with C3-C18 alcohol or cyclohexanol. Said primary intermediate containing nitro- and/or nitrozo- groups is reduced by carbonisation with gas containing carbon monooxide in the presence of water in an overquivalent amount effected with sulphur or sulphur compound having a molar weight between 34 and 90 g. mol-1 in the amount ranging from 0.1 to 10 wt.%, relative to the amount of nitro- and/or nitrozo compound, at a temperature ranging from 70 to 200 degree Celsius and pressure from 1 to 5 MPa, wherein 4-aminodiphenylamine thus obtained is condensed at a temperature ranging from 180 to 250 degree Celsius with C3 - C18 alcohol in the presence of alkaline hydroxide till a desired compound is obtained.

Description

A process for the preparation of said antidegradants of the general formula I, in which R = alkyl and / or isoalkyl having 3 to 18 carbon atoms or cyclohexyl based on at least one intermediate selected from 4-nitrodiphenylamine, 4-nitrosodiphenylamine, 4-nitrosodiphenylamine salt reduction to prepare 4-aminodiphenylamine and therefrom by reductive alkylation with carbonyl compounds having a carbon number of 3 to 18 or by condensation alkylation with an aliphatic alcohol having a carbon number of 3 to 18 or cyclohexanol. The nitro- or nitroso-containing intermediate is carbonylated with carbon monoxide with water in excess of the equivalent of sulfur or a sulfur compound having a molar mass of 34 to 90 g / mol in an amount of 0.1 to 10% by weight, calculated on the nitro- and / or or a nitroso compound at 70 to 200 ° C and a pressure of 1 to 5 MPa, wherein the 4-aminodiphenylamine formed is condensed at a temperature of 180 to 250 ° C with a C 3 -C 16 alcohol with the assistance of an alkali hydroxide on said product.

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The inventor: MACHO VENDELIN, prof. Ing. DrSc., Member correspondent of SAS, PARTIZÁNSKE JUREK LUDOVIT, Ing. CSc., PRIEVIDZA UHLÄR JAN, Ing. CSc., SALA

Name of the invention: Process for the preparation of N-alkyl-N'-phenyl-p-phenylenediamine and / or N-cyclohexyl-N ¹ -phenyl-p-phenylenediamine

Reported:

PV

Process for preparing N-alkyl-N'-phenyl-p-phenylenediamine and / or N-cyclohexyl-N ¹ -phenyl-p-phenylenediamine.

Technical field

The invention relates to a process for the preparation of N-alkyl-N'-phenyl-p-phenylenediamine as well as N-cyclohexyl-N'-phenyl-p-phenylenediamine using as intermediates at least one of 4-nitrodiphenylamine, 4-nitrosodiphenylamine and its salt, from in which 4-aminodiphenylamine is obtained with high selectivity and its main product by reductive alkylation with carbonyl compounds or alkylation condensation with alcohols.

BACKGROUND OF THE INVENTION

N-Alkyl-N'-phenyl-p-phenylenediamines are effective antidegradants (antioxidants, antiozonants) of vulcanized rubbers (natural, synthetic polyisoprene, polybutadiene, butadiene-styrene, butadiene-acrylonitrile, etc.), polyolefins and also polyolefins and increasingly polyolefins lubricating oils. In addition to the antioxidant and anti-ozonant effect in finished products, they also have a beneficial effect on the processability of rubbers and polyolefins, have a dispersing effect on other additives to rubbers, polyolefins and the like.

Several methods are known for the preparation of N-alkyl-N'-phenylenediamines, and perhaps the most widespread is a process for the reductive alkylation of p-aminodiphenylamine prepared from p-nitrosodiphenylamine or p-nitrodiphenylamine on hydrogenation catalysts in aliphatic ketones or aldehydes at 100 to hydrogen 250 ° C [U.S. Patents 2734809 (1956), 3163616 (1964) and 3092662 (1963); British Patents 911931 (1962), 926897 (1961) and 1295672 (1972); U.S. Patent 1077667 (1960)]. Ketones or aldehydes may be replaced by alcohols using a scaffold nickel catalyst [Riece R., Kohn E., J. Am. Chem. Soc. 77, 4052 (1955); CS Patent 87381 (1954); Skripko L. A .: Chim. Think. 1967, no. 5, 343]. However, the disadvantage is the need and consumption of an efficient catalyst which poisones relatively quickly and the need for high purity hydrogen. However, a method of alkylating primary aromatic amines, namely p-aminodiphenylamine with alcohols in the presence of alkali catalysts (NaOH, KOH,

Alkali metal oxides (MgO) [Sprinzak Y., J. Am. Chem. Soc. 78, 3207 (1956)]. In this case, e.g., the mole ratio of p-aminodiphenylamine: a mixture of fatty alcohols _of C ₇ to C _g = 1: 2, using 7% by weight of potassium hydroxide as the catalyst, calculated as 4-aminodiphenylamine, at 150 to 240 ° C, and a reaction time of 3.5 hours, the yield amounts to 99% of N (C _{7 -C)} alkyl-N'-phenyl-p-phenylenediamine [Skripko L Λ. et al., Chim. thought out. 1985, no. 3, 146].

It also follows that the next or even prior stage of the production of the final product is the production of 4-aminodiphenylamine. Among its most important intermediates, mainly used for the production of N-isopropyl-N'-phenyl-p-phenylenediamine, is 4-nitrodiphenylamine, produced by condensation of p-nitrochlorobenzene with aniline, followed by reduction or hydrogenation to 4-aminodiphenylamine, in particular 4-nitrosodiphenyls. prepared by several possible technological variants of nitrosation of diphenylamine, followed by reduction, respectively. by hydrogenation or its alkali salts to 4-aminodiphenylamine. 4-Nitrosodiphenylamine is formed by condensation of p-nitrophenol with aniline, amination of diphenylamine by coupling with diazonium salt, dehydrogenation of hydroaromatic derivatives, with nitrobenzene and other methods [Pašek J., Ph.D. Department of Organic Technology, ICT Prague, Research Institute of Organic Technology at CHZJD Bratislava. Prague (1980); Belgian Patents 627205 (1963) and 618462 (1962); pat. Germany 2633811 (1976); Dutch Pat. 6506527 (1965); British Pat. 975097, 989257 (1962), 1296211 (1969) and 1304525 (1970)]. An interesting process is the addition of nitrosobenzene and azoxybenzene by reduction of nitrobenzene with carbon monoxide using heavy metal oxides as catalyst at 200 to 400 ° C, followed by dimerization of nitrosobenzene to 4-nitrosohydroxylamine and its reduction to 4-aminodiphenylamine. 1259504, 1322531 and 1810828; Germany Pat. 713602 (1977)]. True, the multi-stage process, the need for demanding removal or regeneration of catalysts and their low lifetime do not allow its efficient industrial use. Thus, perhaps the most widely used process for the preparation of the 4-aminodiphenylamine intermediate is a process for reducing or hydrogenating 4-nitrodiphenylamine and in particular 4-nitrosodiphenylamine, respectively. its alkali salts either with disulphide to sodium tetrasulphide (BIOS 986) or

-3vodíkom. In the case of polysulfides, however, their above-stoichiometric amounts are required, which complicates the process not only from a material but also from an ecological point of view. In the case of nickel or noble metal catalysts VIII. In addition to the low lifetime, the technical problem is the regeneration of the catalyst.

SUMMARY OF THE INVENTION

The present invention provides a process for the preparation of N-alkyl-N'-phenyl-p-phenylenediamine and / or N-cyclohexyl-N'-phenyl-p-phenylenediamine of the formula

NH-R wherein R = alkyl or isoalkyl having a carbon number of 3 to 18 or cyclohexyl, based on at least one intermediate selected from 4-nitrodiphenylamine, 4-nitrosodiphenylamine, 4-nitrosodiphenylamine hydrochloride, sodium or potassium salt of 4-nitrosodiphenylamine from which prepared by reduction of 4-aminodiphenylamine and from this by reductive alkylation with a ketone of 3 to 18 carbon atoms at a temperature of 80 to 200 ° C, a pressure of 1 to 20 MPa with hydrogen and a hydrogenation catalyst or condensation alkylation with aliphatic alcohols of 3 to 18; or cyclohexanol, catalyzed by at least one alkali metal hydroxide, carried out in such a way that the nitro- and / or nitroso-containing intermediate is carbonylated with a carbon monoxide-containing gas, with the aid of water in an excess equivalent to the nitro- and / or nitroso-compound. sulfur and / or zl substituting Compound S of molecular weight 34-90 gmol ^-1 from 0.1 to 10% by weight.

calculated on the carbonylation-reduced nitro and / or nitroso compound, at a temperature of 70 to 200 ° C and a pressure of 1 to 30 MPa. The resulting 4-aminodiphenylamine, as a rule at least partially free of unconverted water and by-products, is condensed at a temperature of 180 to 250 ° C with an aliphatic alcohol having a carbon number of 3 to 18 with the aid of an alkali hydroxide.

An advantage of the process according to the invention is that the catalyst system for the carbonylation reduction of 4-nitrosodiphenylamine or 4-nitrodiphenylamine to 4-aminodiphenylamine is readily available and thus inexpensive and efficient. As reducing agent pos

It is a technical to crude carbon monoxide, i.e. no refining, since the sulfur compounds in it, such as carbonyl sulfide, are also used as a catalyst for this reaction, the hydrogen donor being water. Thus, there is no need for molecular hydrogen, and when the 4-aminodiphenylamine N-alkyl is subsequently alkylated with a higher aliphatic or cycloaliphatic alcohol, it is virtually unnecessary to refine the intermediate. Last but not least, the advantage is the flexibility of the process to produce a wider range of N-alkyl-N ¹ -phenyl-p-phenylenediamines on a single device.

According to this process, N-alkyl-N ¹ -phenyl-p-phenylenediamine is produced with alkyls having a carbon number of 3 to 18 or N-cyclohexyl-N'-phenyl-p-phenylenediamine. For the carbonylation reduction of the intermediate 4-nitrodiphenylamine or 4-nitrosodiphenylamine, respectively. their salts, the carbon monoxide-containing gas may be used, which may be pure carbon monoxide, but also in admixture with other gaseous components such as hydrogen, methane, nitrogen and other inert gases, carbon dioxide, carbonyl sulfide and hydrogen sulfide. In addition, carbonyl sulphide and hydrogen sulphide admixtures are desirable since they can completely replace the need for their deliberate addition to the reaction medium as a catalyst or catalyst. a component of a catalytic system for reacting a nitro- or nitrosodiphenylamine to an aminodiphenylamine. The oxygen content of the carbon monoxide-containing gas is also acceptable, since it does not harm the synthesis itself, unless its content is close to the explosive limit. However, it should be appreciated that higher amounts of oxygen can reduce the quality of the intermediate by reacting arylamines with oxygen.

Water is in fact a hydrogen donor in the reaction medium. In order to avoid competitive reactions, such as reductive carbonylation of nitro- and nitro-, respectively. nitrosodiphenylamine, a higher water content in the reaction medium than theoretically necessary for carbonylation reduction is required: c ₆ h ₅ nhc ₆ h ₄ no + 2 co + h ₂ o -------->

- + Ό ₆ Η ₅ ΝΗϋ ₆ Ι { ₄ ΝΗ ₂ + 2 C0 ₂ , resp. C ₆ H ₅ NHC ₈ H ₄ NO ₂ + 3 CO + II ₂ O ------>

- * C ₆ H ₅ NHCgH ₄ NH ₂ + 3 CO ₂ · The molar ratio water / nitro- resp. nitrosodiphenylamine = 5 to 10. However, a ratio greater than 10 impairs the mutual contact of the reactants, especially water, with the nitro- and nitro- or nitro- nitrosodiphenylamines. It therefore requires a higher content of polar, respectively. a heteropolar solvent allowing good contact of water with other components of the reaction medium. This feature can

- at least partially filling the interfacial transfer catalyst, but its elevations contaminate the reaction product, while polar or heteropolar solvents are readily removed from the reaction medium or crude product, e.g. by distillation or extraction.

A basic medium is required for the reaction to proceed, which can usually form alkali metal hydroxide residues, e.g. for the conversion of nitrosodiphenylamine hydrochlorides to its sodium or potassium salt. Furthermore, ammonium hydroxide, which according to the invention is also understood to include free ammonia, since it also forms ammonium hydroxide in the presence of the necessary water. Further, alkali metal alkoxides such as sodium and potassium methoxides to sodium and potassium butoxides. Trialkylamines are also suitable, in particular with alkyls having a carbon number of 1 to 4; triethylamine is particularly suitable since, besides the formation of an alkaline environment, it improves the contact of the reactants, in particular water with nitro- and nitro- nitrosodiphenylamines. Triethanolamine is also useful, but it is possible to react with the hydroxy groups of triethanolamine by reductive carbonylation. When trialkylamines with longer alkyls are used, the contact of water with other reactants is impaired, which negatively affects the reaction rate and selectivity. Again, when primary and secondary amines are used, lower selectivity is achieved due to simultaneous reductive carbonylation. Other tertiary amines are technically and thus more difficult to afford.

When using sulfur as a catalyst or catalyst system, the amount thereof must be in the upper part of the desired amount range, i.e. 5 to 10 wt. nitrosodiphenylamines. Carbon disulfide is considerably more effective, but hydrogen sulfide and carbonylsulfide are sufficient to be of an order of magnitude, of about 1% sufficient for a sufficient reaction rate. Alkali metal sulphide or sulphide is also useful. Particularly suitable are carbonyl sulfide and hydrogen sulfide. Moreover, in the case of both hydrogen sulphide and carbonyl sulphide, which are the most effective, their residues from the crude product can be regenerated or at least technically disposed of. Other sulfur compounds not only with a molar mass of more than 92 g.mol ^-1 but also higher are also useful, but of little use.

The temperature of the carbonylation reduction is in the range of 70 to 200 ° C, most preferably 120 to 150 ° C. At temperatures below 70 ° C the reaction is slow and at temperatures above 200 ° C a markedly lower selection is achieved.

-6-activity to 4-aminodiphenylamine. Pressure ranging from 1 to 30 MPa. The carbonylation reduction of the nitro- and nitrosodiphenylamine according to the present invention takes place even at a pressure of less than 10 bar, but the reaction rate is low and, moreover, the process requires a gas with a high carbon monoxide content.

For better contact of the phases and all the reactants, it is appropriate to carry out the reaction in the presence of solvents, in particular polar organic solvents, dissolving both the organic reactants and water. Most suitable include water-soluble low molecular weight alcohols such as methanol, ethanol, propanol, 2-propanol, tert-butyl alcohol, ketones, especially acetone, dioxane, tetrahydrofuran, diethyl ether, dimethyl glycol ether, dimethyl diglycol ether and the like.

From the crude 4-aminodiphenylamine obtained, the unconverted water and any unconverted 4-nitrosodiphenylamine, respectively, are removed. 4-nitrodiphenylamine as well as low boiling components, in particular solvents and residues from the catalyst system. The technical 4-aminodiphenylamine thus obtained can be distilled under vacuum to obtain pure 4-aminodiphenylamine, which is generally required for reductive N-alkylation, but technical 4-aminodiphenylamine is also suitable for N-alkylation, in particular with higher aliphatic alcohols. Indeed, the course of its alkylation condensation, catalysed mainly by alkali metal hydroxides at 180 to 250 ° C, most preferably 205 to 240 ° C, practically does not affect it. The produced N-alkyl-N'-phenyl-p-phenylenediamine has high antioxidant and anti-ozonant activity, readily achievable dispersity in processed rubbers, in greases and the like. For a high degree of purity it can be distilled on a film evaporator, zone melting, etc.

In carrying out the carbonylation reduction, the 4-nitro- and resp. 4-nitrosodiphenylamine, and also in the treatment of crude 4-aminodiphenylamine, especially in alkylation condensation, it is desirable to protect it from atmospheric oxygen.

Further data on carrying out the production method of the invention as well as other advantages are apparent from the examples.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Condensation of 4-nitrochlorobenzene with aniline is prepared

-74-nitrodiphenylamine, which is weighed in an amount of 50 g into a rotary stainless steel autoclave together with 50 g of dimethyl glycol ether, 100 g of methanol and 50 g of water. To this is added 10 g of a 15 wt.% Methanolic sodium methoxide solution. 0.05 g of ammonium vanadate meta and after closure of the autoclave 0.9 g of hydrogen sulphide and carbon monoxide with an addition of 1.2 vol. % hydrogen, 0.4 vol. % nitrogen, 0.09 vol. % oxygen, 0.1 vol. % carbon dioxide and 0.02 vol. % carbonyl sulfide to a pressure of 6 MPa. Thereafter, the contents of the autoclave are heated to 150 [deg.] C. with constant rotation and maintained at this accuracy to ± 2 [deg.] C. for 4 h. Thereafter, the rotation of the autoclave is stopped, the autoclave is cooled to room temperature, and the non-converted carbon monoxide together with the carbon dioxide formed is discharged. Complete conversion of 4-nitrosodiphenylamine and selectivity is achieved

97.6% to 4-aminodiphenylamine. Separation of solvents and unconverted water yields crude 4-aminodiphenylamine at a concentration of

96.9 masses. %.

of this, a paddle 40 is removed

From cm, and an inert gas inlet

41.9 g of n-nonanol and 4 g of n-nonanol to 4-aminodiphenylamine are g into a three-necked flask with a volume of 250 with a stirrer with a thermometer (fluorescent nitrogen). Potassium hydroxide is then added. A molar ratio of approximately 2: 1. After the air has been removed from the apparatus, the reaction mixture is heated to 210 ± 5 ° C with stirring and maintained for 4 h, while 3.5 g of the reaction water are distilled off. Thereafter, the reaction mixture was cooled to about 80 ° C and neutralized with an aqueous solution of 25 wt. %. The resulting potassium sulphate is separated off by suction filtration at 80 ± 2 ° C under reduced pressure. Excess nonanol and water were distilled off under reduced pressure (2.69 kPa) at 150 ° C. To give 66.4 g of crude N-nonyl-N ^{1-phenyl-p-phenylenediamine,} corresponding to a yield of 97.3% of theoretical. This is further removed under a high vacuum on a film evaporator (sample 1Ά) or as such is applied without further refining as an antioxidant (sample 1B), in particular into rubber mixtures.

Example 2

Following the procedure of Example 1, only 4-aminodiphenylamine was prepared by carbonylation reduction of 4-nitrosodiphenylamine prepared from diphenylamine produced by condensation of aniline at 320 ± 10 ° C, under catalytic conditions.

-8kého effect (NH) 2 ', 4' ^12®, followed by nitrosation of the N-nitrosodiphenylamine and its rearrangement to the 4-nitrosodiphenylamine.

4-Nitrosodiphenylamine in the form of the sodium salt of an aqueous-methanol-toluene solution at a concentration of 19.91% by weight. % of this solution is added to a 1 liter rotary autoclave in an amount of 200 g of this solution, and after closing, 1 g of hydrogen sulfide and carbon monoxide are added to a pressure of 8 MPa. Carbonylation reduction is performed for 4 h. The conversion of 4-nitrosodiphenylamine is 99.6%. The reduced product obtained consists of a solid and a liquid phase, the solid being soluble in toluene and constituting 76.8% by weight. % 4-aminodiphenylamine, 0.18 wt. % Of 4-nitrosodiphenylamine and the liquid contains 40.7 wt. % 4-aminodiphenylamine and 0.2 wt. % 4-nitrosodiphenylamine. After separation of the low-boiling fraction, the condensation was also done with nonanol, yielding N-nonyl-N ¹ -phenyl-p-phenylenediamine of 96.9% (sample 2Ά). In another experiment under otherwise similar conditions, only the condensation of 4-aminodiphenylamine is done in the presence of air, the yield of N-nonyl-N'-phenyl-p-phenylenediamine reaching 98.2% (sample 2B).

Example 3

The procedure is similar to that of Example 2, except that the carbonylation reduction of 200 g of aqueous and resp. aqueous solution of 4-nitrosodiphenylamine sodium with a concentration of 19.2% by weight. % is made in the presence of 0.1 g of ammonium metavanadate, 1 g of carbon disulphide and 1 g of hydrogen sulphide. The conversion of 4-nitrosodiphenylamine is 99.9% and the yield of N-nonyl-N ¹ -phenyl-p-phenylenediamine is 98.9%.

Example 4

4-Nitrodiphenylamine with a purity of 99.3% is weighed in a quantity of 50 g into a 1 liter autoclave together with 100 g of methanol, 5 g of triethylamine, 50 g of water and 0.1 g of ammonium metavanadate and after closing the autoclave 0.6 g of hydrogen sulphide carbon monoxide up to 5 MPa. The carbonylation reduction is carried out at 145 ° C for 4 h. The conversion of 4-nitrodiphenylamine is 99.4% and the selectivity to 4-aminodiphenylamine is 99.2%. After separation of the methanol, the remainder of the water and the triethylamine, condensation is carried out with nonanol, the yield of N-nonyl-N'-phenyl-p-phenylenediamine reaching 98.4%.

Under otherwise similar conditions, but lowering the temperature of the carbonylation reduction of 4-nitrodiphenylamine to 80 ° C and the reaction time to 6

The -9h conversion of 4-nitrodiphenylamine is 98.2% and the selectivity to 4-aminodiphenylamine is 99.7%. The yield of N-nonyl-N'-phenyl-p-phenylenediamine is 98.9%.

Example 5

The procedure is analogous to Example 4, except that the condensation of the 4-aminodiphenylamine is carried out using a mixture of aliphatic alcohols (for C C ^-C ₁₃ iz isoalcohols) in mol. ratio 1: 2 and as a catalyst

4.5 g of sodium hydroxide. The yield of N-alkyl-N ' -phenyl-p-phenylenediamine (wherein alkyl is 11 to 13) is 98.9%.

Example 6

The procedure is analogous to Example 1 except that the carbonylation reduction of 50 g of 4-nitrodiphenylamine is carried out in the presence of 50 g of water, 50 g of dioxane, 50 g of methanol, 1 g of potassium hydroxide and 0.6 g of hydrogen sulphide with 76.3 carbon monoxide,

3.6 hydrogen, 1.4 nitrogen, 0.2 oxygen, 0.6 carbon dioxide and 0.07 carbonyl sulfide, at a total initial pressure at room temperature of 4 MPa, Carbonylation reduction is performed at 120 + 2 ° C for 6 h to achieve complete conversion of 4-nitrodiphenylamine and selectivity to 4-aminodiphenylamine of 99.9%. After separation of the solvent and the unconverted water and the remainder of the catalyst system, pure 4-aminodiphenylamine is isolated. 20 g of this are taken and condensed with stearyl alcohol at 220 ± 5 ° C and mol. ratio of stearyl alcohol: 4-aminodiphenylamine - 2: 1. The yield of N-alkyl-N ¹ -phenyl-p-phenylenediamine with an alkyl number of 18, reaching 99%. Of the other 20 g is reductively alkylated with a mixture of dialkyl C ₁₀ - C _13, prepared by epoxidation of n-alkenes C _lo - C ₁₃ with tert-butyl hydroperoxide at a temperature of 110 ° C catalyzed by an oil soluble molybdenum salt, followed by isomerization epoxyalkanes Cjq - C ^ by the action of zinc chloride. The reductive alkylation is carried out at a temperature

150 ° C, at a hydrogen pressure of 8 to 5 copper-chromium-ferric-calcium

MPa with a catalytic effect of the catalyst in an amount of 20% by weight.

to 4-aminodiphenylamine at a molar ratio

4-aminodiphenylamine: mixture of ketones C ₁₀ - C ₁₃ = 1: 1.2. yield

The N-alkyl-N ¹ -phenyl-p-phenylenediamine in which the alkyl has a carbon number of 10 to 13 reaches 90.2%.

-10Example 7

The antioxidant properties of commercial N-isopropyl-N'-phenyl-p-phenylenediamine (sample A), N-isohexyl-N'-phenyl-p-phenylenediamine (sample B) and N-nonyl-N'-phenyl-p- phenylenediamine, prepared by condensation of 4-aminodiphenylamine with nonanol both in the air (sample 2B of Example 2) and in the non-air (sample 2Λ of Example 2).

The antioxidant properties of said antioxidants are evaluated in a mixture of rubbers with additives having the following composition: 100 masses, parts natural rubber, 50 masses, parts carbon black per 100 masses, parts rubber, 5 masses, parts zinc oxide, 1 masses, part stearin, 2.5 mass , parts of sulfur, 1 part, part of CBS and 2 parts, parts of said antioxidants per 100 parts, parts of natural rubber. In addition, an unprotected mixture, i. without antioxidants (sample 0). The vulcanization temperature is 150 ° C. The samples were subjected to thermo-oxidative aging at 90 ° C. Further conditions and changes in the basic physical-mechanical properties of the vulcanizates during aging are given in Table 1. From the results it is apparent that the highest antioxidant activity is in the sample 2A, i. N-nonyl-N'-phenyl-p-phenylenediamine prepared in the absence of oxygen.

Samples 2A and in particular 2B also have the highest antiozone activity.

In terms of the effect of these antioxidants on the course of sulfur vulcanization of rubber mixtures, an accelerating effect on the course of vulcanization has been demonstrated.

Example 8

The procedure is as in Example 2 and in the second part of Example 6, only the place of the mixture of ketones Cjq - ₃₃ C was used for the reductive alkylation of 4-aminodiphenylamine cyclohexanone. The yield of N-cyclohexyl-N'-phenyl-p-phenylenediamine is 87.6%.

Example 9

The procedure is analogous to Example 3 except that 1.5 g of potassium hydrogen sulphide is applied instead of 1 g of hydrogen sulphide and 0.08 g of vanadium sulphide is used instead of 0.1 g of ammonium metavanadate. Complete conversion of 4-nitrosodiphenylamine is achieved and the yield of N-nonyl-N ¹ -phenyl-p-phenylenediamine is 99.1%.

-11Table 1

Sample designation parameter Thermo-oxidative stress (aging) time at 90 ° C [days] 0 * 3 6 8 0 strength, [MPa] elongation, [%] hardness, [° Sh] modulus 300%, [MPa] 24.1 401 68 17.1 65.1 59.1 + 2 12.8 57.7 53.6 + 2 4.9 26.1 32.7 + 5 4.3 A strength, [MPa] elongation, [%] hardness, [° Sh] modulus 300%, [MPa] 25.3 383 68 18.8 83.4 71.0 +6 14.5 74.3 63.2 + 5 5.6 55.3 49.3 + 5 5.9 B strength, [MPa] elongation, [%] hardness, [° Sh] modulus 300%, [MPa] 23.6 383 67 17.5 79.2 66.6 +5 13.7 69.9 58.0 +7 5.6 61.9 52.5 +6 5.7 2Ά strength, [MPa] elongation, [%] hardness, [° Sh] modulus 300%, [MPa] 24.7 436 67 15.7 93.9 77.5 +6 12.2 87.4 68.1 + 5 5.5 71.7 57.8 + 5 5.3 2B strength, [MPa] elongation, [%] hardness, [° Sh] modulus 300%, [MPa] 25.2 409 68 17.6 90.1 70.7 + 7 14.9 64.3 54.0 + 5 5.7 57.5 48.7 + 6 5.8

Note: Sample parameters achieved after vulcanization are understood.

Example 10

The procedure is analogous to Example 4 except that 100 g of dimethyl glycol is used as solvent instead of methanol. Virtually (99.9%) complete conversion of 4-nitrosodiphenylamine and a yield of N-nonyl-N'-phenyl-p-phenylenediamine of 98.9% was achieved.

Industrial usability

The process of the invention is useful in the chemical industry for the flexible production of N-alkyl-N'-phenyl-p-phenylenediamines as

-12 suitable antioxidants and in part antiozonants for processed rubbers, lubricating oils, including greases, technical products based on polyolefins and the like.

Claims (6)

A process for the preparation of N-alkyl-N'-phenyl-p-phenylenediamine and / or N-cyclohexyl-N'-phenyl-p-phenylenediamine of the general formula wherein R = alkyl and / or isoalkyl of 3 to 18 carbons or cyclohexyl based on at least one intermediate selected from 4-nitrodiphenylamine, 4-nitrosodiphenylamine, 4-nitrosodiphenylamine hydrochloride, sodium or potassium salt of 4-nitrosodiphenylamine, from which it is prepared by reduction of 4-aminodiphenylamine and from this by reductive alkylation of up to 3 carbons in the molecule at a temperature of 80 to 200 ° C, a pressure of from 1 to 20 MPa with the assistance of hydrogen and a hydrogenation catalyst or by condensation alkylation with aliphatic alcohols having a carbon number of 3 to 18 and / or cyclohexanol catalysed by at least one alkali metal hydroxide. and / or the nitroso group is reduced by carbonylation with a carbon monoxide-containing gas, with the aid of water in an excess amount, calculated for the nitro and / or nitroso compound under basic conditions catalyzed by sulfur and / or sulfur compounds on the molecular weight of 34-90 gmol ^"1 in an amount of 0.1 to 10%, calculated on the carbonylation of nitro-reduced and / or nitroso compound, at a temperature of 70 to 200 ° C and a pressure of 1 to 30 MPa, wherein the crude 4-aminodiphenylamine, generally at least partially free of unconverted water and by-products, is condensed at 180-250 ° C with an aliphatic alcohol of 3 to 18 by the action of an alkali hydroxide. Method according to claim 1, characterized in that the intermediate product containing 4-nitrodiphenylamine and / or 4-nitrosodiphenylamine and / or their salts is carbonylated by the action of water in an excess amount, preferably at a molar ratio of water: nitro- and / or nitroso compound = 5 to 20: 1. Production process according to claims 1 and 2, characterized in that the reduction of the nitro- and / or nitroso compound is carried out in the presence of an organic polar solvent, preferably dissolving both the intermediates and 4-aminodiphenylamine. The process according to claims 1 to 3, characterized in that the basic medium is formed by at least one of bases such as alkali metal hydroxide, ammonium hydroxide, alkali metal alkoxide and trialkylamine with alkyls having a carbon number of 1-4. The process according to claims 1 to 4, wherein the sulfur compound is at least one selected from hydrogen sulfide, carbonyl sulfide, carbon disulfide and alkali metal hydrogen sulfide. Process according to claims 1 to 5, characterized in that the reduction of the intermediate is carried out in addition in the presence of a vanadium compound as a promoter, preferably a pentavalent compound, in an amount of 0.001 to 3% by weight, calculated on the nitro and / or nitroso compound. .