CA1210410A - Process for the preparation of diamines of the diphenylmethane series - Google Patents
Process for the preparation of diamines of the diphenylmethane seriesInfo
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- CA1210410A CA1210410A CA000413404A CA413404A CA1210410A CA 1210410 A CA1210410 A CA 1210410A CA 000413404 A CA000413404 A CA 000413404A CA 413404 A CA413404 A CA 413404A CA 1210410 A CA1210410 A CA 1210410A
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- rearrangement
- temperature
- formaldehyde
- condensation
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/68—Preparation of compounds containing amino groups bound to a carbon skeleton from amines, by reactions not involving amino groups, e.g. reduction of unsaturated amines, aromatisation, or substitution of the carbon skeleton
- C07C209/78—Preparation of compounds containing amino groups bound to a carbon skeleton from amines, by reactions not involving amino groups, e.g. reduction of unsaturated amines, aromatisation, or substitution of the carbon skeleton from carbonyl compounds, e.g. from formaldehyde, and amines having amino groups bound to carbon atoms of six-membered aromatic rings, with formation of methylene-diarylamines
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
- Phenolic Resins Or Amino Resins (AREA)
Abstract
ABSTRACT
An improved process for the preparation of diamines of the diphenylmethane series by condensing arylamines in which the para-position relative to the amino group is free, with formaldehyde, followed by rearrangement at elevated tempera-ture, a copolymer of tetrafluoroethylene and perfluorovinyl ethers being used as a heterogeneous acid catalyst. By means of this process the content of polynuclear polyamines with three or more nuclei, in the reaction product, can be re-duced to less than 5% by weight.
An improved process for the preparation of diamines of the diphenylmethane series by condensing arylamines in which the para-position relative to the amino group is free, with formaldehyde, followed by rearrangement at elevated tempera-ture, a copolymer of tetrafluoroethylene and perfluorovinyl ethers being used as a heterogeneous acid catalyst. By means of this process the content of polynuclear polyamines with three or more nuclei, in the reaction product, can be re-duced to less than 5% by weight.
Description
4~
Proces~ for the preparation o diamines of the diphenylme~hane series The invention relates to the preparation o~ di-amines o~ th diphenylmethane series by reacting aryl-amines in which the para-position relative to the amino gr~up is ree, ~ith ~ormaldehyde, using an acidic ion exchanger as a catalyst, the often undesirably high pro-portion of polynuclear co~densation products not exceeding 5 % o~ average; in contrast to all the processes kno~
hitherto~
As ic knoun, diamine~ o~ the diphe~ylmethane serie~ are ormed ~r~ the corresponding amine4 and form-aldehyde via condensa~ion to give me~hylenedianilines or aminobenzylanilines, uhich are then rearranged to the end products with the aid of acid catalysts, i~ ~hich process the reaction course indicated in European Patent Application 0,014,927 is likely to apply.
It has already been proposed in G2rman Auslege-schrit 1,210,872 to use, as acid catalysts, acids ~hichare presen~ in a heterogeneous phase during the reaction, -and sulonated copolymers of ~yrene and divinyl-benzene kno~n as io~ exchangers ~ere especially preferred.
Thi5 made it possible $o avoid the expensive uorking-up compared with the formerly cus~omary processes u~ing mineral acids as catalysts.
These types of solid~ strongly acidic resins, in addi~ion to more weakly acidic ion e~hchangers, have also been usedD according to German Of~enlegungsschri~t
Proces~ for the preparation o diamines of the diphenylme~hane series The invention relates to the preparation o~ di-amines o~ th diphenylmethane series by reacting aryl-amines in which the para-position relative to the amino gr~up is ree, ~ith ~ormaldehyde, using an acidic ion exchanger as a catalyst, the often undesirably high pro-portion of polynuclear co~densation products not exceeding 5 % o~ average; in contrast to all the processes kno~
hitherto~
As ic knoun, diamine~ o~ the diphe~ylmethane serie~ are ormed ~r~ the corresponding amine4 and form-aldehyde via condensa~ion to give me~hylenedianilines or aminobenzylanilines, uhich are then rearranged to the end products with the aid of acid catalysts, i~ ~hich process the reaction course indicated in European Patent Application 0,014,927 is likely to apply.
It has already been proposed in G2rman Auslege-schrit 1,210,872 to use, as acid catalysts, acids ~hichare presen~ in a heterogeneous phase during the reaction, -and sulonated copolymers of ~yrene and divinyl-benzene kno~n as io~ exchangers ~ere especially preferred.
Thi5 made it possible $o avoid the expensive uorking-up compared with the formerly cus~omary processes u~ing mineral acids as catalysts.
These types of solid~ strongly acidic resins, in addi~ion to more weakly acidic ion e~hchangers, have also been usedD according to German Of~enlegungsschri~t
2,037,550, as catalyst~ or the reaction of arylamines ~ith formaldehyde, it being emphasized that, vQthin the ~raction o bi~u~lear compounds, the ~ormation o~ 2,4'-isomers o~ the dime~hylamino-diphenylmethanes is favored by raising the temperature during the rearrangement and by increasing the molar ratio of amine to formaldehyde, ~hilst at the same time the amount of 4,4'-isomer formed decreases. In this process, the polymer mixture usually contains about 20 to 35% by ~eight o~ ami~es ~ith 3 or more nuclei, a~d in only one case, namely a one-~tep reaction at 190G~ contain~ less than 10%, i.e. 7.8%, th~re being-~no statement on the yield of diamines or polya~ines and their purity. In this process, the ~ater o~ condensation is removed continuously during the r,earrangement.
In contrast~ according to European Patent Application 778, the ~ater of condensatio~ i5 not distilled of~ in the ~ame reaction and when using sulonated styrene/divinylbenzene copolymers ~ith a particular degree o~ crosslinking, a high content of the 4~4'-isomer in the diamine fraction is achieved. In this process, the content of trinuclear or ~etranuclear compounds i~ alway~ distinctly more than 10%, i.e~ ~4 to 18%.
Finally, it has already been proposed, according to U~.Patent Speci~ication 4,0~1,078, to use ~luorine~containing catalystsO i.e. n uorinated graphite~ In this process~ how-evèr9 ~he content o~ diamines i5 only 43~8 tO 64~6%o Nevertheless~ because the binuclear compounds in particular are valuable starting materials for the prepara-tion o diisocyanates, a high proportion of polyamines is undesirable4 Surprisingly, it has now been found that~he content o~ polynuclear compounds in the e~d product can be reduced to less than 5% ~y using, a~ ~he catalyst, ion exchangers containing perfluoroalkyl group5 and sulPonic acid group5.
The diamine mix~ures obtained in this case are moreover disti~guished in that they co~tain ~irtually no impurities consisting of non-rearranged initial products.
The invention thus relates to an improved process for the preparation of diamines oP the diphenylmethane series by condensing mono~uclear ary1amines in ~hich the paraposi-tion relative to the amino grOUP is ~ree, ~ith formaldehyde or uith subs~ances which release Po~maldehyde under the re-action conditions, Pollo~ed by rearrangemen~ at elevated temperature and in the presence of an acid ion exchanger containing sulfonic acid groups, as a catalyst, water being
In contrast~ according to European Patent Application 778, the ~ater of condensatio~ i5 not distilled of~ in the ~ame reaction and when using sulonated styrene/divinylbenzene copolymers ~ith a particular degree o~ crosslinking, a high content of the 4~4'-isomer in the diamine fraction is achieved. In this process, the content of trinuclear or ~etranuclear compounds i~ alway~ distinctly more than 10%, i.e~ ~4 to 18%.
Finally, it has already been proposed, according to U~.Patent Speci~ication 4,0~1,078, to use ~luorine~containing catalystsO i.e. n uorinated graphite~ In this process~ how-evèr9 ~he content o~ diamines i5 only 43~8 tO 64~6%o Nevertheless~ because the binuclear compounds in particular are valuable starting materials for the prepara-tion o diisocyanates, a high proportion of polyamines is undesirable4 Surprisingly, it has now been found that~he content o~ polynuclear compounds in the e~d product can be reduced to less than 5% ~y using, a~ ~he catalyst, ion exchangers containing perfluoroalkyl group5 and sulPonic acid group5.
The diamine mix~ures obtained in this case are moreover disti~guished in that they co~tain ~irtually no impurities consisting of non-rearranged initial products.
The invention thus relates to an improved process for the preparation of diamines oP the diphenylmethane series by condensing mono~uclear ary1amines in ~hich the paraposi-tion relative to the amino grOUP is ~ree, ~ith formaldehyde or uith subs~ances which release Po~maldehyde under the re-action conditions, Pollo~ed by rearrangemen~ at elevated temperature and in the presence of an acid ion exchanger containing sulfonic acid groups, as a catalyst, water being
- 3 -present in both steps, wherein a copolymer of ~etra~luoro-ethylene with perfluorovinyl ethers containing sulfonic acid groups is used as the catalyst, which is present~at least during the rearrangement, a molar ratio o~ arylamine to formaldehyde of 2.5:1 to 15:1 being employed.
.
The reaction is pre~erably carried out in two separate reaction steps. AdYantageously, a reaction tempe-rature in the range from 20 to 90C i5 chosen for the con-densation and a reaction temperature in the range from 40to 190C is chosen ~or the rearrangement, it being ad~an-tageous to use a higher temperature in the rearrangement than in the condensation. Preferably, howeverD the conden-sation is carried out at 30 to 50C and the rearrangement a~ 40 to 190C.
In this process, particularly favorable results are obtained i~ the temperature chosen for the rearrange-meng is not immediately in the upper part of the tempera-ture range according to the invention, but is raised stepwise within this range.
The catalyst can ~e added immediately in the condensation, but it i5 also equally possible to add the catalyst to the reac~io~ mixture only before the re-arrangement.
The formaldehyde is pre~erably used in the reac-~ion as an aqueous solution, but it can also be added in the ~orm of a gas. Paraformaldehyde may be men~ioned in particular as a substance ~hich releases formaldehydeD
The water which is introduced into the condensa-tion step, or which is formed in ~he latter, can be sub-stantially removed before the start o~ -the rearrangement, ~or example by phase separation, a residual amount of water remaining in the reaction mixture. However,it is equally possible to leave the water in the reaction mix-ture, this being a procedure which makes it possible tocarry out the reaction in a single step. The amount o~
water which is presen~ has-virtually no ef~ect on the result o~ the reaction or rearrangement, which sho~s that the conditions prevailing in the presence of the catalyst ~L2~
chosen according to the invent10n ar~ d1fferent from those preva;ling ;n the case of the acid;c ;on exchange resins used earl1er.
A large number of arylamines are suitable as start-ing mater;als ~see, for example, European Patent Appl;cation0,014,927). ~owever, a~;line, o-tolu;dine, o-chloro-ani~ine, o-anisidine and N-methylanil~ne are particu-. Iarly suitable.
The reaction can be carried out batch~ise or con-t~nuously; in the latter case, the ~ixture of condensa-t~on products ~N-methylenediamines and aminobenzylani-l~nes) formed ;n the f;rst step of the reaction course ~s passed over a bed of the ion exchanger used according to the invention as the catalyst. In~ the batchw;se pro-ce~s, the ion exchanger can be added immed;ately at thestart of the react;on. HoweverO ;t ~s also possible for the condensat;on reaction to proceed to completion first and then the ion exchanger to be addedO ~hich then causes the rearrangement to giYe the end products and must be separated off again during the ~orking-up. The reaction temperatures bo~h for the condensat;on and also for the subsequent rearrangement to give the end products influence the rate of the overall reaction and the degree of purity of the particular end product, as a function of the reacti`vity of the arylamine used, and this can be seen from the practical examples. Simi~ar~yO
the chosen molar rat;o of aryLamine to formaldehyde also has an influence.
Thus, for example, with a molar ratio ani~ine :
formaldehyde of 10 . 1, it ;s poss;ble to obtain a parti-cularly high proportion of binuclear compounds t95.8X) at relat;vely low rearrangement temperatures (85C) ~see Example 1). On the other hand, if ~he molar ratio aniline : formaldehyde were to be reduced to 2~5 : 1 ;n this particular case, ~he rearrangement temperature being approximately the same, the proportion of binuclear com-pounds ~ould decrease to about 90X~
Furthermore, by varying the rearrangement tempera-ture, ;t is possible to mod;fy the percentage composition - s -~thin the b~nuclear amines fract;on. If, for example, in a cont;nuous process in a tube reactor fi~led uith ion ex-changer a~l the temperature zones are kept at 1~0Cr the proportion of 2,4-diaminod~phenylmethane can be ;ncreased to 23X ~ith a molar rat;o ani~;ne : formaldehyde of 10 : 1, uhilst the proportion of 4,4'-diam;nod;phenylmethane decreases correspond;n0ly ~see Examp~e 1 or Example 4).
~ f it ;s desired, for instance ~hen us;ng an;l;ne9 to obtain a part;cularlr high proport;on of 4,4'-d;am;no-1D diphenylmethane in the react;on mixture, th;s is bestaccomplished by raising the rearrangement temperatures stepwise ~see Exa~ple 5~
The react;on times are temperature-dependent and are usually 1 to 4 hours for the condensation and about 1 to 7 hours ~or the rearrangementO
The molar ratio of ary~am;ne to formaldehyde i5 between 2.5 : 1 and 15 : ~, ;t also being advantageous to use a high arylamine : formaLdehyde ra~io ;nstead of an inert solvent, such as xy~ene, in the case ~here the viscosity ~ould increase to an undesirable extent.
The copolymers of tetrafluoroethylene ~ith per-f~uorov;ny~ ethers conta;n;ng sulf3n;c ac;d groups, used accord;ng to the invent;on as the cata~ys~, are kno~n.
Theycontain the groupings:
F-c-(x)n-ocF2~cFR~s03H
or F - C - (X) - OCF - CF2R
n CF2 SOj~H
I
;n uh;ch n denotes an integer from 1 to 5, R denotes a fluorine atom or a monovalent perfluoroalkyl radical and X represents the groups OtCF2)m, OCF2CFY or OCFYCF2, ~here m represents an ;nteger from 2 to 10 and Y
lZ~
1 represents a fluorine atom or a trifluoromethyl group~
The preparation of such resins is described in U.SO Patent NosO 3,282~875 and 3,882~0930 Amongst these catalysts, those having the structural formula (I):
-[ ~CF2-CF2)m CiF CF2~n [ CF 2 ~ -fF-CF
fF2 ~F2 in which formula m denotes 5 to 13 r 5~ n denotes approxi-mately 1,000 and Z denotes 1, 2, 3 ..0, are particularly preferredO Products of this type are marketed under the name NAFION( ).
As catalysts for the process according to the invention, they have the advantage that they fully retain their activity over long productio~ periodsO If they should ever lose activity~ they can be regenerated by treatment with strong mineral acids`, even with con-centrated nitric acid.
During the rearrangement, care should be~taken to ensure the most intimate contact possible between the catalyst and the mixture of the starting materials or precondensation productsD
The compounds prepared according to the invention are converted to isocyanates with phosgene and are used as starting materials for the preparation of rigid and flexible polyurethane foams. The examples which follow are intended to illustrate the process according to the invention in greater detail.
~' Example 1:
1st st~p:
Preparation of the condensation products 6.58 moles of formaldehyde as a 37X strength 5 aqueous solut;on are introduced, ~;th intens;ve st;rring, at room temperature, into a soLution cons;sting of 65.85 moles of aniline and 3.0 kg of water tmolar ratio ani-line 0 formaldehyde = 10-1). The react;on m;xture ;s then kept at 50C for 2 hours and cooled. After separa-10 t;on of the aqueous phase from the organ;c phase, thelatter is fed d;rectly to the acid-catalyzed rearrange-ment.
2nd step:
Rearrangement of the condensation prsducts prepared in 15 the first step to g;ve the end products 520 9 of a copoLymer of the structural formula I
tNAF10N~R)~ having an exchange capacity of 0c83 miLli-equ;vaLentlgO in the H~ form, is fil~ed, as the cata-Lyst, ;nto a tube reactor ~29.5 x 900 mm) subd;vided into 20 9 temperature zones. 40 g/hour of the condensation pro-ducts prepared in the first step are then fed continu ously into the reactor via a meter;ng pump. All 9 temp-erature zones are kept at 85C. The reaction mixture LeaYing at the upper end has the foLlo~ing composit;on 25 after the excess aniline has been distilled of~:
0.8X by ~eight of 2,2'-diaminodiphenylmethane 10.7X by ~eight of 2,4'-diaminodiphenylmethane 84.3X by ~eight of ~,4'-d;am;nod;phenylmethane and 3.6X by ~eight of trinucLear compound.
The rema;n;ng 006X by weight consists of poly-nuclear compounds ~hich are not identif;ed more prec;sely either here or ;n the follo~ing examples.
Example 2:
Example 1 ;s repeated, the onLy d;fference being 35 that all 9 temperature zones of the reactor are kept at OOC .
The polyamine mixture obtained has the follo~;ng composit;on:
1.7X by we;ght of 2,2'-diam;nodiphenylmethane o 18.1Z by we;ght o~ 2~4'-d;am;nodiphenylmethane 76.0X by ~eight of 4,4'-d;am;nodiphenylmethane and 3.~X by we;ght of erinuclear compound.
Example 3:
5 Preparation of the precondensation products 15 moles of formaldehyde ~37X strength solut;on) are ;ntroduced, w;th intensivs stirr;ng, at room tempera-tl3reO ;nto a solut;on cons;st;ng of 45 moles of anil;ne and 2 kg of ~ater ~molar rat;o aniline : formaldehyde =
13 3:1). The rea~t;on mixture is kept at 50C for about 2 hours and cooLed. After the aqueous phase has been sepa-rated off, the react;on m;xture is fed directly to the re-arrangement effected by ion exchanger.
The precondensat~ produGt prepared in this way 15 ~s then treated as in Example 1, the reaction tempera-tures being set as follows in a total of 9 zones:
Z~nes 1 and 2: 70C
Z~nes 3 and 4: 80C
Zones 5 to 8: 90C
20 Zone 9: 110C
Th;s gives a polyamine m;xture hav;ng the follow-ing composition:
1.5X by ~e;ght of 2,2'-diam;nod;phenylmethane 19.2X by ~e;ght of 2,~'-d;am;nodiphenylmethane 25 71.8X by weight of 4~4'-diaminodiphenylmethane and 6.9X by we;ght of arylamines ~ith 3 or more nuclei Example 4:
Example 1 ;s repeated, the only d;fference be;ng that all 9 temperature zones o~ the reactor are kept at 30 130~
Th;s g;ves a polyam;ne mixture having the foLlow-ing composition:
2.7% by ~eight of 2,2'-diam;nod;phenylmethane 23.2X by weight of 2,4'-d;aminod;phenylmethane 35 o9.3X by weight of 4~4'-d;aminodiphenylmethane and
.
The reaction is pre~erably carried out in two separate reaction steps. AdYantageously, a reaction tempe-rature in the range from 20 to 90C i5 chosen for the con-densation and a reaction temperature in the range from 40to 190C is chosen ~or the rearrangement, it being ad~an-tageous to use a higher temperature in the rearrangement than in the condensation. Preferably, howeverD the conden-sation is carried out at 30 to 50C and the rearrangement a~ 40 to 190C.
In this process, particularly favorable results are obtained i~ the temperature chosen for the rearrange-meng is not immediately in the upper part of the tempera-ture range according to the invention, but is raised stepwise within this range.
The catalyst can ~e added immediately in the condensation, but it i5 also equally possible to add the catalyst to the reac~io~ mixture only before the re-arrangement.
The formaldehyde is pre~erably used in the reac-~ion as an aqueous solution, but it can also be added in the ~orm of a gas. Paraformaldehyde may be men~ioned in particular as a substance ~hich releases formaldehydeD
The water which is introduced into the condensa-tion step, or which is formed in ~he latter, can be sub-stantially removed before the start o~ -the rearrangement, ~or example by phase separation, a residual amount of water remaining in the reaction mixture. However,it is equally possible to leave the water in the reaction mix-ture, this being a procedure which makes it possible tocarry out the reaction in a single step. The amount o~
water which is presen~ has-virtually no ef~ect on the result o~ the reaction or rearrangement, which sho~s that the conditions prevailing in the presence of the catalyst ~L2~
chosen according to the invent10n ar~ d1fferent from those preva;ling ;n the case of the acid;c ;on exchange resins used earl1er.
A large number of arylamines are suitable as start-ing mater;als ~see, for example, European Patent Appl;cation0,014,927). ~owever, a~;line, o-tolu;dine, o-chloro-ani~ine, o-anisidine and N-methylanil~ne are particu-. Iarly suitable.
The reaction can be carried out batch~ise or con-t~nuously; in the latter case, the ~ixture of condensa-t~on products ~N-methylenediamines and aminobenzylani-l~nes) formed ;n the f;rst step of the reaction course ~s passed over a bed of the ion exchanger used according to the invention as the catalyst. In~ the batchw;se pro-ce~s, the ion exchanger can be added immed;ately at thestart of the react;on. HoweverO ;t ~s also possible for the condensat;on reaction to proceed to completion first and then the ion exchanger to be addedO ~hich then causes the rearrangement to giYe the end products and must be separated off again during the ~orking-up. The reaction temperatures bo~h for the condensat;on and also for the subsequent rearrangement to give the end products influence the rate of the overall reaction and the degree of purity of the particular end product, as a function of the reacti`vity of the arylamine used, and this can be seen from the practical examples. Simi~ar~yO
the chosen molar rat;o of aryLamine to formaldehyde also has an influence.
Thus, for example, with a molar ratio ani~ine :
formaldehyde of 10 . 1, it ;s poss;ble to obtain a parti-cularly high proportion of binuclear compounds t95.8X) at relat;vely low rearrangement temperatures (85C) ~see Example 1). On the other hand, if ~he molar ratio aniline : formaldehyde were to be reduced to 2~5 : 1 ;n this particular case, ~he rearrangement temperature being approximately the same, the proportion of binuclear com-pounds ~ould decrease to about 90X~
Furthermore, by varying the rearrangement tempera-ture, ;t is possible to mod;fy the percentage composition - s -~thin the b~nuclear amines fract;on. If, for example, in a cont;nuous process in a tube reactor fi~led uith ion ex-changer a~l the temperature zones are kept at 1~0Cr the proportion of 2,4-diaminod~phenylmethane can be ;ncreased to 23X ~ith a molar rat;o ani~;ne : formaldehyde of 10 : 1, uhilst the proportion of 4,4'-diam;nod;phenylmethane decreases correspond;n0ly ~see Examp~e 1 or Example 4).
~ f it ;s desired, for instance ~hen us;ng an;l;ne9 to obtain a part;cularlr high proport;on of 4,4'-d;am;no-1D diphenylmethane in the react;on mixture, th;s is bestaccomplished by raising the rearrangement temperatures stepwise ~see Exa~ple 5~
The react;on times are temperature-dependent and are usually 1 to 4 hours for the condensation and about 1 to 7 hours ~or the rearrangementO
The molar ratio of ary~am;ne to formaldehyde i5 between 2.5 : 1 and 15 : ~, ;t also being advantageous to use a high arylamine : formaLdehyde ra~io ;nstead of an inert solvent, such as xy~ene, in the case ~here the viscosity ~ould increase to an undesirable extent.
The copolymers of tetrafluoroethylene ~ith per-f~uorov;ny~ ethers conta;n;ng sulf3n;c ac;d groups, used accord;ng to the invent;on as the cata~ys~, are kno~n.
Theycontain the groupings:
F-c-(x)n-ocF2~cFR~s03H
or F - C - (X) - OCF - CF2R
n CF2 SOj~H
I
;n uh;ch n denotes an integer from 1 to 5, R denotes a fluorine atom or a monovalent perfluoroalkyl radical and X represents the groups OtCF2)m, OCF2CFY or OCFYCF2, ~here m represents an ;nteger from 2 to 10 and Y
lZ~
1 represents a fluorine atom or a trifluoromethyl group~
The preparation of such resins is described in U.SO Patent NosO 3,282~875 and 3,882~0930 Amongst these catalysts, those having the structural formula (I):
-[ ~CF2-CF2)m CiF CF2~n [ CF 2 ~ -fF-CF
fF2 ~F2 in which formula m denotes 5 to 13 r 5~ n denotes approxi-mately 1,000 and Z denotes 1, 2, 3 ..0, are particularly preferredO Products of this type are marketed under the name NAFION( ).
As catalysts for the process according to the invention, they have the advantage that they fully retain their activity over long productio~ periodsO If they should ever lose activity~ they can be regenerated by treatment with strong mineral acids`, even with con-centrated nitric acid.
During the rearrangement, care should be~taken to ensure the most intimate contact possible between the catalyst and the mixture of the starting materials or precondensation productsD
The compounds prepared according to the invention are converted to isocyanates with phosgene and are used as starting materials for the preparation of rigid and flexible polyurethane foams. The examples which follow are intended to illustrate the process according to the invention in greater detail.
~' Example 1:
1st st~p:
Preparation of the condensation products 6.58 moles of formaldehyde as a 37X strength 5 aqueous solut;on are introduced, ~;th intens;ve st;rring, at room temperature, into a soLution cons;sting of 65.85 moles of aniline and 3.0 kg of water tmolar ratio ani-line 0 formaldehyde = 10-1). The react;on m;xture ;s then kept at 50C for 2 hours and cooled. After separa-10 t;on of the aqueous phase from the organ;c phase, thelatter is fed d;rectly to the acid-catalyzed rearrange-ment.
2nd step:
Rearrangement of the condensation prsducts prepared in 15 the first step to g;ve the end products 520 9 of a copoLymer of the structural formula I
tNAF10N~R)~ having an exchange capacity of 0c83 miLli-equ;vaLentlgO in the H~ form, is fil~ed, as the cata-Lyst, ;nto a tube reactor ~29.5 x 900 mm) subd;vided into 20 9 temperature zones. 40 g/hour of the condensation pro-ducts prepared in the first step are then fed continu ously into the reactor via a meter;ng pump. All 9 temp-erature zones are kept at 85C. The reaction mixture LeaYing at the upper end has the foLlo~ing composit;on 25 after the excess aniline has been distilled of~:
0.8X by ~eight of 2,2'-diaminodiphenylmethane 10.7X by ~eight of 2,4'-diaminodiphenylmethane 84.3X by ~eight of ~,4'-d;am;nod;phenylmethane and 3.6X by ~eight of trinucLear compound.
The rema;n;ng 006X by weight consists of poly-nuclear compounds ~hich are not identif;ed more prec;sely either here or ;n the follo~ing examples.
Example 2:
Example 1 ;s repeated, the onLy d;fference being 35 that all 9 temperature zones of the reactor are kept at OOC .
The polyamine mixture obtained has the follo~;ng composit;on:
1.7X by we;ght of 2,2'-diam;nodiphenylmethane o 18.1Z by we;ght o~ 2~4'-d;am;nodiphenylmethane 76.0X by ~eight of 4,4'-d;am;nodiphenylmethane and 3.~X by we;ght of erinuclear compound.
Example 3:
5 Preparation of the precondensation products 15 moles of formaldehyde ~37X strength solut;on) are ;ntroduced, w;th intensivs stirr;ng, at room tempera-tl3reO ;nto a solut;on cons;st;ng of 45 moles of anil;ne and 2 kg of ~ater ~molar rat;o aniline : formaldehyde =
13 3:1). The rea~t;on mixture is kept at 50C for about 2 hours and cooLed. After the aqueous phase has been sepa-rated off, the react;on m;xture is fed directly to the re-arrangement effected by ion exchanger.
The precondensat~ produGt prepared in this way 15 ~s then treated as in Example 1, the reaction tempera-tures being set as follows in a total of 9 zones:
Z~nes 1 and 2: 70C
Z~nes 3 and 4: 80C
Zones 5 to 8: 90C
20 Zone 9: 110C
Th;s gives a polyamine m;xture hav;ng the follow-ing composition:
1.5X by ~e;ght of 2,2'-diam;nod;phenylmethane 19.2X by ~e;ght of 2,~'-d;am;nodiphenylmethane 25 71.8X by weight of 4~4'-diaminodiphenylmethane and 6.9X by we;ght of arylamines ~ith 3 or more nuclei Example 4:
Example 1 ;s repeated, the only d;fference be;ng that all 9 temperature zones o~ the reactor are kept at 30 130~
Th;s g;ves a polyam;ne mixture having the foLlow-ing composition:
2.7% by ~eight of 2,2'-diam;nod;phenylmethane 23.2X by weight of 2,4'-d;aminod;phenylmethane 35 o9.3X by weight of 4~4'-d;aminodiphenylmethane and
4.7Z by weight of trinuelear compound Example 5:
Example 1 ;s repeated, the only difference be;ng that the tube reactor is subdiv;ded ;nto d;fferent _ 9 _ temperature zone ~zones 1 ~ 2: 70~C; zones 3 to 8:
90C; 20ne 9: 110C).
The polyam;ne mlxture obta;ned has the foll~ing GompoS;t;on:
O.9X by ~eight of 2,2'-d;am;nod;phenylmethane 11.1X by weight of 2,4'-diam;~od~phenylmethane 85.1X by weight of 4,~'-d;am1nod;phenylmethane and 2.8X by weight of trinuclear compound Example 6:
10 Preparation of the precondensate and the end product ;n one s~ep 1 mole of formaldehyde as a 37X strength aqueous solution is introduced in the cours~ of 1 hour, ~;th stirring, at 90C, ;nto a mixture consist;ng of 10 moles 15 of o-tolu;d;ne9 600 ~ of the catalyst indicated in Example 1, in the H~ form, and 2 kg of water ~molar ratio a~;ne : forma~dehyde = 10:1).
The mixture is kept at 90C for a further 3.5 hours. After the catal~st has been filtered off, the 20 water and the excess o-tolu;dine are d;stilled off. The react;on m;xture contains 93X by ~e;ght of 4~ d;amino-3,3'~dimethyl-diphenylmethane. The impurities consisting of polynuclear compounds amount to 1 to 2X by ~eight.
Example 7:
1 mole of formaLdehyde as a 37X streng~h aqueous solution ;s ;ntroduced in the course of 30 m;nutes, at 20CO ~;th ;ntens;ve st;rr;ng, ;nto a solut;on consist-ing of 10 moles of N-methyl-anil;ne and 10 kg of ~ater 5molar ratio N-methylanil;ne : formaldehyde = 10:1).
After the aqueous phase has been separated off, 400 9 of the catalyst accord;ng to Example 1, in the H~ form, are added to the organic phase. The reac~ion m;xture ;s then kept at 120~G for 2 hours. The catalyst is f;l-tered off and the excess N-methyl-an;line ;s dist;lled 35 off. The reaction m;xture contains 94X by ~eight of 4,4'-di --(me~hy~ o~-d;phenylmethane. Impurities cons;sting of polynuclear compounds amount to about 2% by weightO
Example 8:
1 mole of formaldehyde as a 37X strength aqueous sslution is added drop~ise, at 20~, ~ith intensive st~rring, to a solut;on cons;sting of 10 moles of o-chloro-~niline and 2 kg of water ~molar rat;o o-chloro-an;L;ne :
formaldehyde - 10:1).
After the aqueous phas2 has been separated off, 500 9 of the catalyst accord;n~ to Example 1 are added and the ~ixture ;s heated to 130C. After 2~5 hours~ the cata-. Iyst ;s filtered off and the excess o-chloro-an;L;ne ;s d;sti~led off. The reaction mixture contains a3x by 10 ~e;ght of 4,4'-diamino-3,3'-dichloro-diphenylmeth3ne and about 10X by weight of 2,4'-d;am;no-3,3'-d;chloro-d;phenyl-methane.
Examp~e 9:
~ mo~e of forma~dehyde as a 37~ strength aqueous 15 solution ;s introduced, ~ith intensive st;rringO into a solution cons;st;ng of 10 moles of 2-methoxy-an;line and 4~kg of ~ater ~mo~ar ratio 2~methoxy-anil;ne~r formaLde-hyde = 10:1).
After the aqueous phase has been separated off, 500 9 20 of the catalyst ~ccording to xample 1 are added to the reaction mixture. The reaction ~ixture is kept at 90C
for 1.5 hours. The catalyst 1s then filtered off and the excess 2 methoxy-aniline is disti~ed off~ The reaction m;xture contains ~OX by ~e;ght of 4,4'-diamino-3,3'-25 dimethoxy-d;phenylmethane, about 4X by ~eight of 2,~'-diam;no-3,3'-dimethoxy-diphenylmethane and about 3X by ~e;ght of ;mpur;t;es containing 3 or more nucle;.
Example 1 ;s repeated, the only difference be;ng that the tube reactor is subdiv;ded ;nto d;fferent _ 9 _ temperature zone ~zones 1 ~ 2: 70~C; zones 3 to 8:
90C; 20ne 9: 110C).
The polyam;ne mlxture obta;ned has the foll~ing GompoS;t;on:
O.9X by ~eight of 2,2'-d;am;nod;phenylmethane 11.1X by weight of 2,4'-diam;~od~phenylmethane 85.1X by weight of 4,~'-d;am1nod;phenylmethane and 2.8X by weight of trinuclear compound Example 6:
10 Preparation of the precondensate and the end product ;n one s~ep 1 mole of formaldehyde as a 37X strength aqueous solution is introduced in the cours~ of 1 hour, ~;th stirring, at 90C, ;nto a mixture consist;ng of 10 moles 15 of o-tolu;d;ne9 600 ~ of the catalyst indicated in Example 1, in the H~ form, and 2 kg of water ~molar ratio a~;ne : forma~dehyde = 10:1).
The mixture is kept at 90C for a further 3.5 hours. After the catal~st has been filtered off, the 20 water and the excess o-tolu;dine are d;stilled off. The react;on m;xture contains 93X by ~e;ght of 4~ d;amino-3,3'~dimethyl-diphenylmethane. The impurities consisting of polynuclear compounds amount to 1 to 2X by ~eight.
Example 7:
1 mole of formaLdehyde as a 37X streng~h aqueous solution ;s ;ntroduced in the course of 30 m;nutes, at 20CO ~;th ;ntens;ve st;rr;ng, ;nto a solut;on consist-ing of 10 moles of N-methyl-anil;ne and 10 kg of ~ater 5molar ratio N-methylanil;ne : formaldehyde = 10:1).
After the aqueous phase has been separated off, 400 9 of the catalyst accord;ng to Example 1, in the H~ form, are added to the organic phase. The reac~ion m;xture ;s then kept at 120~G for 2 hours. The catalyst is f;l-tered off and the excess N-methyl-an;line ;s dist;lled 35 off. The reaction m;xture contains 94X by ~eight of 4,4'-di --(me~hy~ o~-d;phenylmethane. Impurities cons;sting of polynuclear compounds amount to about 2% by weightO
Example 8:
1 mole of formaldehyde as a 37X strength aqueous sslution is added drop~ise, at 20~, ~ith intensive st~rring, to a solut;on cons;sting of 10 moles of o-chloro-~niline and 2 kg of water ~molar rat;o o-chloro-an;L;ne :
formaldehyde - 10:1).
After the aqueous phas2 has been separated off, 500 9 of the catalyst accord;n~ to Example 1 are added and the ~ixture ;s heated to 130C. After 2~5 hours~ the cata-. Iyst ;s filtered off and the excess o-chloro-an;L;ne ;s d;sti~led off. The reaction mixture contains a3x by 10 ~e;ght of 4,4'-diamino-3,3'-dichloro-diphenylmeth3ne and about 10X by weight of 2,4'-d;am;no-3,3'-d;chloro-d;phenyl-methane.
Examp~e 9:
~ mo~e of forma~dehyde as a 37~ strength aqueous 15 solution ;s introduced, ~ith intensive st;rringO into a solution cons;st;ng of 10 moles of 2-methoxy-an;line and 4~kg of ~ater ~mo~ar ratio 2~methoxy-anil;ne~r formaLde-hyde = 10:1).
After the aqueous phase has been separated off, 500 9 20 of the catalyst ~ccording to xample 1 are added to the reaction mixture. The reaction ~ixture is kept at 90C
for 1.5 hours. The catalyst 1s then filtered off and the excess 2 methoxy-aniline is disti~ed off~ The reaction m;xture contains ~OX by ~e;ght of 4,4'-diamino-3,3'-25 dimethoxy-d;phenylmethane, about 4X by ~eight of 2,~'-diam;no-3,3'-dimethoxy-diphenylmethane and about 3X by ~e;ght of ;mpur;t;es containing 3 or more nucle;.
Claims (8)
1. A process for the preparation of diamines of the diphenylmethane series by condensing mononuclear aryl-amines in which the para-position relative to the amino group is free, with formaldehyde or with substances which release formaldehyde under the reaction conditions, followed by rearrangement at elevated temperature and in the presence of an acid ion exchanger containing sulfonic acid groups, as a catalyst, water being present in both steps, which comprises using a copolymer of tetrafluoroethylene with perfluorovinyl ethers containing sulfonic acid groups as the catalyst, which is present at least during the rearrange-ment, a molar ratio of arylamine : formaldehyde of 2.5 : 1 to 15 : 1 being used.
2. A process as claimed in claim 1, wherein a temperature of 20 to 90°C is used during the condensation and a temperature of 40 to 190°C is used during the rearrangement step.
3. A process as claimed in claim 1, wherein the temperature during the rearrangement step is increased step-wise within the range from 40 to 190°C.
4. A process as claimed in claim 1, wherein the condensation step is carried out at a temperature of 30 to 50°C.
5. A process as claimed in claim 1, wherein the rearrangement step is carried out at a temperature of 80 to 130°C and is increased stepwise within this range.
6. A process as claimed in claim 1, wherein the bulk of the water is separated off after the condensation.
7. A process as claimed in claim 1, wherein the condensation and rearrangement are carried out in a single reaction step.
8. A process as claimed in claim 1, wherein the arylamine is aniline.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19813142529 DE3142529A1 (en) | 1981-10-27 | 1981-10-27 | METHOD FOR PRODUCING DIAMINES OF THE DIPHENYLMETHANE SERIES |
| DEP3142529.1 | 1981-10-27 | ||
| AT0463381A AT371433B (en) | 1981-10-27 | 1981-10-30 | METHOD FOR PRODUCING DIAMINES OF THE DIPHENYLMETHANE SERIES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1210410A true CA1210410A (en) | 1986-08-26 |
Family
ID=25601361
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000413404A Expired CA1210410A (en) | 1981-10-27 | 1982-10-14 | Process for the preparation of diamines of the diphenylmethane series |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0078414B1 (en) |
| JP (1) | JPS5883658A (en) |
| AT (1) | AT371433B (en) |
| CA (1) | CA1210410A (en) |
| DE (1) | DE3142529A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008001492A1 (en) * | 2008-04-30 | 2009-11-05 | Evonik Degussa Gmbh | Process for the preparation of diaminodiphenylalkanes |
| CN113754545A (en) * | 2021-10-22 | 2021-12-07 | 江苏清泉化学股份有限公司 | Method for synthesizing 3,3 '-dimethyl-4, 4' -diaminodiphenylmethane |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1179945B (en) * | 1962-12-11 | 1964-10-22 | Basf Ag | Process for the preparation of 4,4'-diaminodiphenylmethanes |
| DE1210872C2 (en) * | 1963-09-28 | 1973-01-25 | Basf Ag | Process for the preparation of 4,4'-diaminodiphenylmethanes |
| BE641078A (en) * | 1963-12-11 | |||
| FR1549769A (en) * | 1966-12-20 | 1968-12-13 | ||
| BE754023A (en) * | 1969-07-31 | 1971-01-28 | Kaiser Aluminium Chem Corp | PROCESS FOR THE MANUFACTURE OF POLYAMINES |
| DD109615A1 (en) * | 1972-08-14 | 1974-11-12 | ||
| US3882093A (en) * | 1974-01-02 | 1975-05-06 | Du Pont | Sulfonyl-containing fluorocarbon vinyl ethers and ion exchange membrane formed therefrom |
| US4041078A (en) * | 1976-09-30 | 1977-08-09 | Texaco Development Corporation | Method of preparing polyaminopolyphenylmethanes |
| DE2736862A1 (en) * | 1977-08-16 | 1979-03-01 | Bayer Ag | PROCESS FOR PRODUCING POLYAMINES OF THE DIPHENYLMETHANE SERIES |
| EP0009094B1 (en) * | 1978-09-12 | 1982-04-14 | GebràDer Sulzer Aktiengesellschaft | Process for the preparation of methylene-bridge polyaryl amines |
| US4259526A (en) * | 1979-02-21 | 1981-03-31 | Bayer Aktiengesellschaft | Process for the preparation of mixtures of polyamines of the polyamino-polyaryl-polymethylene type |
-
1981
- 1981-10-27 DE DE19813142529 patent/DE3142529A1/en not_active Withdrawn
- 1981-10-30 AT AT0463381A patent/AT371433B/en not_active IP Right Cessation
-
1982
- 1982-10-08 EP EP82109328A patent/EP0078414B1/en not_active Expired
- 1982-10-14 CA CA000413404A patent/CA1210410A/en not_active Expired
- 1982-10-27 JP JP57187661A patent/JPS5883658A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| ATA463381A (en) | 1982-11-15 |
| DE3142529A1 (en) | 1983-05-05 |
| AT371433B (en) | 1983-06-27 |
| EP0078414A1 (en) | 1983-05-11 |
| JPS5883658A (en) | 1983-05-19 |
| EP0078414B1 (en) | 1984-12-19 |
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