DE2027057A1 - Process for the preparation of polyary amines containing methylene bridges - Google Patents

Description

PATENT LAWYERS
DR.-IMG. H. FINCKB

'"> IP1 ..- ING.H. DOHR, nan

DIPL-INO. 3..3TAEGER. MO N C H EN 5- 2 JULY 970

MÜLLERSTR. 31

Portfolio 22265-Dr. K.
Case D 21968

Imperial Chemical Industries Ltd. London, UK

Process for the production of methyl bridges Polyarylamines

Priority: June 9, 1969 - Great Britain

The invention relates to the production of diaminodiaryl methanes and other related methylene-bridged polyarylamines with higher functionality through condensation of aromatic amines with formaldehyde.

The production of polyarylamines containing methylene bridges by condensation of arylamines with formaldehyde in the presence of acids such as hydrochloric acid for the production of condensates, the diamines, triamines and polyamines of higher functionality hold is well known. Venn e.g. aniline as the primary If arylamine is used, then the methyl bridges contain containing polyarylamines 2,4'- and 4,4'-diaminodiphenylmethanes the formula

^GH 2 -

009851/2206

and

E ₂ H __

CH,

NH

the triamine 2,4-bis <p-aminobenziy ^ aniline of the formula

*O

HH,

CH *

NH,

and related compounds with higher AI infimctionality. If the arylamine consists of aniline, then they own the general formula

BRA.

NH,

-OH ₂

n-1

where η is 1 or flour ¹ .

It has been found that the production of diaminodiaryl methanes and other methylene bridges

009851/2236

BATH ORIGINAL

Polyarylamines using strong organic acids carried out as a catalyst with a pKa value of less than 1.5 can be.

Thus, according to the invention, aleo becomes a method of manufacture proposed of polyarylamines containing methylene bridges, which is carried out by having a primary arylamine and formaldehyde at an elevated temperature in the presence of a strong organic carboxylic acid that has a pKa-Vert of less than 1.5, condenses.

In the method according to the invention, the most varied primary arylamines or mixtures of primary arylamines can be used, uad the process is particularly suitable for primary arylamines which contain a single aromatic nucleus which is unsubstituted in the p-position to the amino group is. A preferred arylamine is aniline.

Examples of primary arylamines that can be used in the process according to the invention are: aniline, m-toluidine, o-toluidine, p-toluidine, m-, o- and p-ethylaniline and the like Isomers of propylaniline, butylaniline and octylaniline, o-, m- and p-anisidine and phenetidine, 2,3,5-trimethylaniline, a> naphthylamine, 2,4- and 2,6-xylidinediamine, 2,4- and 2,6-diethylanilia, 2-methyl-6-ethyl-aniline, m-benzylaniline, o- and m-chloroaniline, p-, m- and o-kitroaniline, m-bromoaniline, 2,4- and 2,6-tolylenediamine, 1.5 "phthylenediamia and o- and m-phenylenediamia. -

In the process according to the invention, the formaldehyde is expedient. moderately used in the form of an aqueous solution. Commercially available solutions with a concentration of 35 "to 4Ö # can be used.

009851/223 6

It is noted that even formaldehyde generator such as ¹ paraformaldehyde and trioxane, which generate in situ formaldehyde used can ground v /.

In the process according to the invention, all organic carboxylic acids, which have pKa values of less than 1.5 as a catalyst be used. Examples of such acids are oxalic acid, trifluoroacetic acid, trichloroacetic acid, dichloroacetic acid, Difluoroacetic Acid and Heptaflio3Ö3utyric Acid »

The organic carboxylic acid is used in catalytic amounts, and preferably in such amounts that the molar ratio of arylamine to acid is greater than 1000: 1 and preferably is between 1200: 1 and 100,000: 1.

The organic carboxylic acid becomes the main reactant . added before they are heated together «

The catalytic effect of the organic carboxylic acid can through The addition of a neutral metal salt can be supported.

Examples "of neutral metal salts that can be used aind: sodium chloride, sodium bromide, sodium fluoride, sodium iodate, Sodium sulphate, sodium benzene sulphonate and similar lithium, Potash, rubidium, calcium, barium, beryllium, magnesium, Aluaiaium-. Hangan, zinc and nickel salts.

The halides represent alkali including alkaline earth metals and preferred neutral salts. ,, \\ '■■■■■■.

■ U- · - The neutral salt is used-la comparatively small Μβ & φβφ, for example ia Hengaa from 0.1 to 10 G «w .- ^ dos total weights Avta prlt & arem amine and formaldehyde!

0 0 9 8 51/2236 bad original

However, Kengen can also be used outside of these limits will. ·

The ratios of arylamine to formaldehyde which can be used in accordance with the invention are 30 as is known in the art. For example, molar arylamine / formaldehyde ratios can be / 1 "use of about 1.5 to 12/1. The invention is particularly useful _v if molar ratios of aryl amine to formaldehyde of 1.6 / 1 to 6/1 is used.

The present method is carried out by the mixes primary arylamine, formaldehyde, etc. together and exposes the mixture to elevated temperatures, which means that the reaction mixture is warmed above room temperature. After that initial mixing of the reactants, the remainder of the reaction is expediently above a temperature of 90 ° G executed.

The process is expediently carried out by first adding the formaldehyde to the aniline, the catalyst and, if appropriate, the neutral salt being premixed with the aniline or the formaldehyde before the addition. Alternatively, the catalyst and optionally also the neutral salt can be added to the mixture of aniline and formaldehyde. After the first, occurring when mixing the reaction, a further isomerization reaction is carried out in which the reaction mixture is heated preferably above 120 ⁰ O for an appropriate time to a temperature of. A preferred temperature range for heating is between 150 and 350 ° C.

i ■.! ■■■■ -

i i ■ '■.

The inventive. Process can ^ under atmospheric pressure ■ or under above atmospheric pressure. It will "prefers heating at a pressure above atmospheric

\ '009851/2236 bad original - 5 - ^copy

To perform pressure.

The heating time required to complete the condensation depends to a certain extent on the catalyst used, on its amount and on the temperature and pressure conditions genes under which the reaction is carried out.

When using elevated temperatures in the order of I50 to 200 ⁰ C, the reaction is over in a few hours. However, this time can be reduced even further if one works at higher temperatures.

The process of the invention can be batchwise or continuously be performed. It is particularly suitable for one continuous operation where the ingredient is continuously mixed and then passed through a heating zone with the desired Temperature and the desired pressure the residence time in the heating zone bo is chosen that completion of the reaction at the respective temperature is ensured.

One form of apparatus suitable for continuous operation of the process is shown in the attached Drawing shown and described in Example 10.

The process can optionally be carried out in the presence of an organic Solvent-be carried out, which is either in addition to or instead of a larger part of the water. However, the presence of an organic solvent is not a preferred feature of the invention.

After completion of the reaction Prodiakt can in the manner customary for such condensations way be isolated, although it aatürlieh enders as in the case · -. A procedure b @ ± fes GSEB © quantities "·" be used hydrochloric acid, is not mofcig, © is Alkali susugeVen,

009861/2238. ■ '■. "■ · ^Ι;

to neutralize the acidic catalyst. Dor catalyst, can of course be neutralized if necessary. Bas reaction mixture katm are subject to a destination, and although preferably under reduced pressure, around vaseer, solvent and eliminate primary arylamine. The leolation process may include filtration or sieving to remove extraneous solids if necessary.

After removing water, solvent and arylamine the product can be used as such for phosgenation into a polyocyanate composition, or it can subjected to distillation to obtain lower boiling products such as diaminodiarylraethanes.

The method according to the invention is suitable for production of diaminodiarylmethanes, which means that relatively high arylamine / formaldehyde ratios can be used, and that the product can be distilled to produce a purified diamino di diaryl methane, such as a purified one Diaminodiphenylmethane, which is suitable for conversion into a Diisocyaniitodipbenylinethan suitable in the production of Polyurethane fin elastomers, etc. can be used. If proportionate low arylamine / formaldehyde ratios are eliminated then the process is suitable for the preparation of mixed polyaryl amines which have polyethylene backings in addition to the diamines, various Kengen triamines and Contain polyarylamines of higher functionality. Such products can be phosgenated without distillation Polyisocyanate compositions are obtained, which are particularly suitable for the production of foamed polyurethanes, and especially of the hard type, are suitable.

"The invention is illustrated in more detail by the following examples." All parts and percentages are expressed in weight, nothing is indicated in the opposite direction.

~ 7 - 009851/2236

BAD ORJGlNAL

example 1

81.1 parts of 37% aqueous formaldehyde, the pH of which has previously been adjusted to 6.2 to 6.3, and then 0.55 part of 6.3 are added to 39 & parts of well-stirred aniline over a period of about 10 minutes % i® © »aqueous solution from, oxalic acid dihydrate & rat sugesetsat« The reaction is exothermic and the temperature & @@ (tesisel & s rises from 23 to 48 ⁰ O during the addition.

3.75 parts sodium chloride are then added to this mixture, and the mixture is introduced into a stainless steel autoclave for a further 15 minutes of stirring. The autoclave is closed and 6 st lamg imt © r Eühren at 190 to 200 ⁰ C heated.

After cooling down, the? Autoclave ®mtl @@ rt and 2 parts of a 5% aqueous Hatriuacariionatlettng © m & ug © g © b © So the reaction mixture is then stirred, * wd the entire® mass and some aniline are distilled to a bridge of 15 mm Hg removed. The Bückütamd wia? D d & s & filtered the insoluble inorganic Sals® to b @ seitlg © m _$ umd finally the rest of the überscMssigen Ämilias by distillation in a DüanfllaBverdarapfer at a brackish-won 15 to 20 eliminates ram Hg.

The product is a clear brawA®e viekosas oil, which according to a gas-liquid B-Oto @ iaatogeapM® (Q ₀ LM *) contains the following:

21.0% 2.4 · - «» ·

Example 2

372 parts reddened Amilim are

0ιΠθβςι / 093β

81.1 parts of 37% aqueous formaldehyde were added over 10 minutes, the pH of which had previously been adjusted to 6.55 and which was then 0.35 parts. a 16.3% trichloroacetic acid solution had been added. The reaction is exothermic and the temperature of the mixture rises from 21 to 48 ° 0 during the addition. After stirring for about 15 minutes, the reaction mixture is transferred to a stainless steel autoclave, and the autoclave is closed and, with stirring, to 190 for 6 hours heated to 200 ^{0 O.}

After cooling, the autoclave is emptied and 2 parts of one 5% aqueous sodium carbonate solution is added. That The reaction mixture is then stirred and all of the water and some aniline are distilled off. The residue is filtered, to remove traces of insoluble materials, and finally the remainder of the excess aniline is removed by distillation in a thin film evaporator under reduced pressure.

The product consists of a clear, brown, viscous oil. One Gas-liquid ear chromatographic analysis showed that the product contained the following:

4.0 % 2,2'-diaminodiphenyl methane

23.5 % 2.4 ·, »""

43 % 4.4 * - w ■ η n

The remainder of the product consisted essentially of methylene-bridged polyarylamines.

Example 3

The procedure is as in Example 1, but 81.1 parts of a 37% aqueous formaldehyde are used, the pH of which had been adjusted to 6.33 and that, then 0.35 part, of a 16.3 % aqueous trichloroacetic acid solution had been added . *

BATH ORIGINAL

';. <"' 009851/2236 ~ 9 ~

The product was _{analyzed by G®L ffi} Q «. The analysis concluded that the product contained the following
4.1 % a ^ '- Diaminodipheaylmetkaa
23 % 2,4'- "n-"
4.3 % 4,4 '· - ". ^N

The remainder consisted of polyaryl amines with higher functional methylene bridges.

Example 4

The procedure is as in Example 1, except that 81.1 parts 37% aqueous formaldehyde can be used, its pH previously set to 6.25, "was" then 0.35 parts added to an 11.4% strength aqueous trifluoroacetic acid solution had been.

The product was analyzed by G. »L» G ». The analysis showed that ß the product emthielts the following

4.3% 2,2'-diaminodiphenylm @ tham
21 % 2,4'- «H *

% 4 ₉ 4 - η η η

The haste consisted of more highly functional ffethyleiit> i * ück © a exhibiting Polyarylamines »

Example 5

To 372 parts of a stirred, aniline during uagefahr 10 ffiia 81.1 parts 37% aqueous formaldehyde added to the previously 0.55 parts of a 16% 3% aqueous Srichioroiissigsaurelösung had been added® The Heaktioa is exothermic, and the temperature of the Gemiseha rises near the addition of * 23 on

Naob. eiasra magafähr I5 mim last © 3? md © n Eührea. WiM the Esaktidns- = »

BATH ORIGINAL

mixture transferred into a stainless steel autoclave, the autoclave is closed and then 6 st with stirring to 190 bis Heated 2OO ° C. After cooling down, the autoclave is emptied, and there are 2 parts of a 5% aqueous sodium carbonate DÖBung admitted. The reaction mixture is then stirred, and all of the water and some aniline are removed by distillation at a pressure of 15 mm Hg. The residue is then filtered, in order to remove insoluble inorganic salts, and finally 6. the remainder of the excess aniline is removed by dissolution removed in a thin film evaporator at a pressure of 15-20 mm Hg.

The product, a clear brown oil, was identified by G.L.C. analyzed » Analysis shows that it contained the following:

3.4% 2,2 ¹ -diaminodiphenylmethane

21 % 2,4'- η η ti
45 % 4,4'- ■ η. n «

The rest of the material consisted essentially of higher-function » nellen polyarylamines containing methylene bridges.

Example 6

81.1 parts of 37% aqueous formaldehyde, to which 0.35 part of a 6.3% aqueous trifluoroacetic acid solution had previously been added, are added to 382.5 g of o-chloroaniline while stirring for 1C to 15 min. The reaction is exothermic and the temperature of the reaction mixture increases during the addition of 27 to 47 ⁰ C. LAOH a short stir the Eβaktionsgemiseh is v.berführt in iron rofctfreien steel autoclave and the autoclave with stirring for 5 .If st at 22O ⁰ C heated.

After the autoclave has cooled down, it is emptied and after 2 parts of a 5% aqueous sodium carbonate solution have been added, all of the water and sfrwau c-Chlorcsnili-n by distillation £ ■■ "; j. ou removed Per it residue becomes .'i aiii ;. ~ '" ^! trotted

009ί :, ' - ■ - ::. ■. e ./ ·

"BAD ORIGINAL

2027067

to remove traces of inorganic materials and finally the remainder of the excess o-chloroaniline is removed by distillation in a thin film evaporator.

The product is a viscous oil that slowly solidifies. It ■ was annulated by gas-liquid chromatography. The analysis showed that the product contained:

2.5% 2.2 ^l -DiamiMO-3.3 ^l -dichlorodiphenylmethane 24 % 2,4'- ⁿ -3,3'- " ^M " 55 # · 4,4 · - "-3,3'-"""

The best of the product consisted essentially of methylene bridges containing polyarylamines with a higher amine functionality, which were derived from o-chloroaniline.

Example 7

The procedure of Example 6 was repeated, but instead of the 382.5 parts of o-chloroaniline, 428.6 parts of o-toluidine were used and the autoclave was heated to 200 to 220 ° C. for 5 hours became. ·

The product was analyzed by Gae liquid chromatography . The analysis showed that the product received:

3 % 2.2 ^l -diamino-3 »3'-diiaethyldiphenylmethane 18.5 % 2,4 · - ⁿ -3,3'- η · η η

The best of the material consisted essentially of methylene bridges. having polyary! amines »a with higher amine functionality, the derived from o-toluidine.

Example 8

The procedure of Example 1 was repeated except that an-; The 81.1 parts of aqueous formaldehyde represent 162.2 parts of 37% aqueous formaldehyde was used, which was previously 4.0 parts

009851/2236 _1Λ1 . **

ORIGINAL BATHROOM -

Salt and 0.55 parts of a 6.3% oxalic acid solution were added was. 372 parts of the aniline were used. The reaction conditions and the work-up were the same, with the difference that that no aqueous sodium carbonate was used.

The product was analyzed by gas-liquid chromatography. The analysis showed that the product contained the following:

3 % 2,2'-diaminodiphenyl methane
13 % 2,4'- """
28 % 4,4'- " ^M "

The rest of the material consisted essentially of methylene bridges containing folyarylamines with higher amine functionality

Example 9

The experiment of Example 1 was repeated, with the difference that a mixture of 300 parts of aniline and 75 parts of o-toluidine ' instead of 372 parts aniline was used *.

The product, a clear brown viscous oil, essentially passed from isomeric diaminodiphenylmethanes and ffethyleribrücken containing polyarylamines with audible amine functionality, the Aminophenyl and Aminoorthochlorophenylreste contained.

Example 10

This example was carried out in the device shown in the drawing executed.

In the drawing the different parts of the device are designated as follows:

* 1 and 2 entries for aniline or formaldehyde / acid /

Salt mixture.

3 first mixing containers

4 pump

5 WASTE VALVES

0 0- ίΠ S 1 / i> 2 3 fj

,. BATH ORIGINAL

6 pressure gauges

7 safety valves (bursting disc)

8 reactor heating tanks

9 reactor coil

10 cooling containers

11 cooling coil

12 Valve for continuous pressure reduction

13 Outlet for product isolation

Aniline was continuously with vigorous stirring in the primary Mixing container mixed with aqueous formaldehyde (35 * 8%), the previously 0.05 part of trifluoroacetic acid and 4.2 (file sodium chloride per 100 parts of 35 * 8% foiraldehyde solution have been added was. The ratio of aniline to formaldehyde was 3.2 parts to 0.68 parts.

They temperature was maintained during the HLschens to 80 to 85 ° C * The 80 to 85 ⁰ G-containing reaction mixture was then via the pump 4 having a pressure of 68 ₉ 6 at continuously through a group consisting of a stainless steel tube reactor 9 pumped, which on 255 to 260 ° 0 was held. The residence time of the reaction mixture in the heated reactor was about I5 min. After leaving the reactor, the mixture was cooled in line 11 to 6O ⁰ C and then discharged through the valve 12 for continuous pressure reduction for the isolation of the product. After the aqueous phase had been separated off and after washing with water, the excess aniline was distilled off under reduced pressure. The product, a light brown viscous oil, contained 64 % diaminodipheny / methane, the remainder in the Weseat ^ borrowed from polyary / amines containing methylane bridges higher amine functionality.

Claims (10)

Claims 1. A process for the preparation of _x XTo lyarylaminen having methylene bridges by condensation of a primary arylamine and formaldehyde at elevated temperature in the presence of an acid, characterized in that a strong organic carboxylic acid with a pKa value of less than 1.5 is used as the acid. 2. The method according to claim 1, characterized in that the primary arylamine contains a single aromatic nucleus, which is unsubstituted in the p-position to the amfno group. 3. The method according to claim 2, characterized in that as primary arylamine aniline is used. 4. The method according to any one of the preceding claims, characterized in that that the organic carboxylic acid is used in such an amount that the molar ratio of arylamine to acid is between 1200: 1 and 100,000: 1. 5 »Method according to one of the preceding claims, characterized in that that a neutral metal salt is also present ". 6. The method according to claim 5ι, characterized in that as neutral metal salt, a halide of an alkali or alkaline earth metal is used. 7ο method according to any of the preceding claims characterized in overall _t, the molar ratio of aryl amine to formaldehyde is between 1.6 / 1 and 6/1. 8. The method according to any one of the preceding claims, characterized in that ge-'kennzeichru-t, that the reactionists 11 takers ge mi set 1 · and then 009851/2 236 BATH ORIGINAL 2027067 are heated to a Terapex * ature in the range of I50 to 35O ^e C. 9 * Method according to one of the preceding claims, characterized in that ge indicates that the respondents are in excess of the atmosphere Pressure to be heated. 10. The method ntich one of the preceding claims, characterized ge indicates that it is carried out in a continuous manner 0IPI.-IN6 H.BOK ». DIPL-HüS BAD ORiGiNAL 16 009851/2236