CA1207340A - Diamines and a process for their preparation - Google Patents
Diamines and a process for their preparationInfo
- Publication number
- CA1207340A CA1207340A CA000395138A CA395138A CA1207340A CA 1207340 A CA1207340 A CA 1207340A CA 000395138 A CA000395138 A CA 000395138A CA 395138 A CA395138 A CA 395138A CA 1207340 A CA1207340 A CA 1207340A
- Authority
- CA
- Canada
- Prior art keywords
- diamines
- mixture
- formula
- isomers
- homologues
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/30—Low-molecular-weight compounds
- C08G18/32—Polyhydroxy compounds; Polyamines; Hydroxyamines
- C08G18/3225—Polyamines
- C08G18/3237—Polyamines aromatic
- C08G18/324—Polyamines aromatic containing only one aromatic ring
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C205/00—Compounds containing nitro groups bound to a carbon skeleton
- C07C205/06—Compounds containing nitro groups bound to a carbon skeleton having nitro groups bound to carbon atoms of six-membered aromatic rings
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/08—Processes
- C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
Abstract
DIAMINES AND A PROCESS
FOR THEIR PREPARATION
ABSTRACT OF THE DISCLOSURE
A mixture of homologues and isomers of diamines corresponding to the formula in which R represents a saturated, straight-chained ali-phatic hydrocarbon group having 8-15 carbon atoms is prepared by nitration and hydrogenation of alkylbenzenes.
The alkylbenzenes employed have a boiling range of 10-50°C
within the temperature range of from 270-330° C(at 1013 mbar).
The diamines thus-produced are liquid at room temperature and are substantially free of undesirable monoamines. These diamines are particularly useful as chain lengthening agents in the production of polyisocyanate addition products.
FOR THEIR PREPARATION
ABSTRACT OF THE DISCLOSURE
A mixture of homologues and isomers of diamines corresponding to the formula in which R represents a saturated, straight-chained ali-phatic hydrocarbon group having 8-15 carbon atoms is prepared by nitration and hydrogenation of alkylbenzenes.
The alkylbenzenes employed have a boiling range of 10-50°C
within the temperature range of from 270-330° C(at 1013 mbar).
The diamines thus-produced are liquid at room temperature and are substantially free of undesirable monoamines. These diamines are particularly useful as chain lengthening agents in the production of polyisocyanate addition products.
Description
~.~2Q'7~
Mo-2325 LeA 20,830 DIP~lINES AND A PROCESS
FOR THEI~ ~RE~AR~ION
BACKGROUND OF THE INVENTION
_ This invention relates to alkyl-substituted phenyl-ene diamines in the form of homologous or isomeric mix-tures and a process for their preparation. These dia-mines are useful as chain lengthening agents in the pro-duction of polyurethanes.
Aromatic diamines are a known class of compounds.
The simplest representatives of this class of compounds (i.e. the isomeric phenylene and tolylene diamines) are crystalline substances at room temperature. Because of this crystallinity, they have not been usRd to any signi-ficant extent as chain lengthening agents for the produc-tion of polyurethanes.
The preparation o~ long-chain dinitroalkylbenzenes is described in US Patent 2,934,571. According to US
Patent 2,986,576, such compounds may be converted into the corresponding diamines. The alkylbenzenes used as starting material in the examples of US Patent 2,934,571 are largely compounds characterized by a branch-chained oligopropylene side chain. In US 2,934,571, however, a special process for nitrat;ng these hydrocarbons is taught since conventional processes o nitration appear to have failed to nitrate the exemplified hydrocarbons to the corresponding dinitroalkylbenzenes. In spite of the elaborate process described in US Patent 2,934,571 ~in which sulfuric acid containing sulfur trioxide is used) it has been found that the end products contain troublesome residues of mononitro compounds. Further reaction of this disclosed nitration product to produce diamines inevitably leads to diamines containing an , ~o-2325 ~ ,, ,,,:
3~ .
undesirable amount of monoamines. Such a mixture of these ~diamines is not very useful as a chain lengthening agent in the production of polyurethanes. Consequently, the products of the above-described process have not been used 5 on a commercial scale by those in the art of polyurethane chemistry.
SUMMARY OF TEE rNVENTION
It is an object of the present invention to provide simple aromatic diamines, i.e. diamines having a single 10 aromatic nucleus and two aromatically bound primary amino groups.
It is also an object of the present invention to provide simple aromatic diamines which are liquid at room temperature and show no tendency to crystallize at room 15 temperature.
It is another object o the present invention to provide simple aromatic diamines which arè liquid at room temperature and which are substantially free o undesir-able monoamines.
It is a further object of the present invention to provide simple aromatic diamines which are liquid at room temp~rature and which may be used as reactants in the production of polyisocyanate addition products.
It is yet another object of the present invention 25 to provide a simple process for the production of simple aromatic diamines which are liquid at room t~mper~ture.
These and other objects which will be apparent to those skilled in the art are accomplished by nitrating and hydrogenating a hydrocarbon ~aving a boiling range of 30 270-330C which hydrocarbon corresponds to the formula R
~`
.
Mo-2325 ~2~3'1~
in which R represents a saturated, straight-chained ali-phatic hydrocarbon group having 8-15 carbon atoms.
The thus-produced diamine is a mixture of homologues and isomers of diamines corresponding-to the formula R
H2N ~ NH2 in which R is as defined above.
DETAILED DESCRIPTION OF TH~ INVENTION
The present invention relates to diamines correspond-ing to the formula:
R
H2N ~ ~ NH2 15 in which R denotes a saturated, straight-chained, alipha-tic hydrocarbon group having 8 to 15 carbon atoms.
These diamines are mixtures of homologues and isomers of the diamines corresponding to this formula. Such diamines are obtained by dinitration, ollowed by hydrogenation of 20 the nitro groups, of hydrocarbons corresponding to the formula:
R
in which R is as defined above. These hydrocarbons have a boiling range according to ASTM D 86 of 10-50C within the temperature range of from 270 C to ioo~c at 1013 mbar.
This invention also pr.ovides a process for the preparation of such diarnines in which a mixture of homo-Mo-2325.
?73~
logues and isomers of the above-described hydrocarbons is converted by nitration in known manner into dinitro com-pounds corresponding to the formula:
R
02N~} N02 10 and these dinitro compounds are subsequently hydrogenated to orm the corresponding diamines in known manner.
The diamines thus-produced are particularly useful as chain lengthening agents for the production of poly-urethanes by the isocyanate polyaddition process.
The starting materials used in the process of the present invention are mixtures of alkylbenzenes corre-sponding to the formula:
in which R represents a saturated, straight-chained ali-phatic hydrocarbon group having 8-15 (preferably 10-13) carbon atoms.
25 These alkylbenzenes are in the form of a mixture of homo-logues and isomers, which have a boiling range (according to ASTM D 86) of 10-50 C, preferably 20-30 C within the Semperature range of from 270 C to 330 C at 1013 mbar.
It is preferred that the alkylenebenzene mixture be such that at least 30 volume percent boils at a tempera-~ure below the middle of the boiling range and at least 30 volume percent boils at a temperature above the middle of the boiling range.
Mo-2325 ~ 2V~
The preparation of such alkylbenzene mixtures may be carried out by techniques known to those skilled in the art. ~ne such procedure is alkylation of benzene with appropriate commercial linear olefin mixtures.
5 Suitable linear olefin mixtures include commercial oligo-ethylene mixtures,other linear oligoolefins and commercial linear alkyl chloride mixtures such as those described, for example, in Kirk-Othmer, Encyclopedia of Chemical Technology, third edition, Vol. 2, (1978), pages 50 to 61.
In the process of the present invention, conversion o the alkylbenzenes into the corresponding dinitro compounds may be carried out by known nitration techniques.
In one such method, 2 to 3 mol of concentrated nitric acid are added for each mol of alkylbenæene with the 15 temperature being maintained at 10-30C. The nitric acid used may be in the form o a mixture with concentrated sul~uric acid (nitrating acid). 95~ of all the nitro groups in the alkyl-substituted dinitrobenz~nes obtained by this proces.s are determined by nuclear resonance 20 measurements (NMR)~ to be in the meta-position with respect to each other. About 10 to 30 wt ~ of the dini-trated alkylbenzenes should be l-alkyl-2,6-dinitrobenzenes and about 70 to 90 wt % should be 1-alkyl-2,4-dinitro-benzenes. This distribution of isomers is not, however, 25 essential to the invention. It would he equally possihle, for example, to carry out the next stage of the process of the present invention with dinitrated a~.kylbenzenes in which the above-mentioned isomers are present in different quan-titative proportions. For example, the .nitrobenzene could 30 be a 1-alkyl-2,4-dinitrobenzene fr~e from the 2,6-isomer.
Such a dinitrobenzene may be obtained, for example, by a two-stage nitration of an alkylbenzene in which the 1-alkyl-4-nitrobenzene obtained as an intermediate stage is Mo-2325 Z~3~
~ (, first separated from the nitration product an~ the~ di-nitrated before hydrogenation i~ be~un.
Use of the alkyl benzene mixtures required in the present invention as starting material yields dinitroalkyl-5 benzene mixtures in which virtually no troublesome mono-nitro constituents are present. The absence of such mono-nitro constituents may be confirmed by determination of the nitro group content and by thin layer chromatographic investigations of the products of nitration. These 10 dinitroalkyl benzene mixtures are particularly suitable for direct conversion to the diamines of the present invention since they require no elaborate methods of purification ~e.g. removal of mononitro compounds by distillation under speciic conditions). Such purifica-15 tion procedures are generally undesirable because aromaticnitro compounds readily decompose in the presence of heat.
The ne~t stage o the process of th~ present inven-tion is hydrogenation of the nitro groups to the corre-sponding primary amino groups. This hydrogenation may be 20 carried out by techniques known to those in the art. In one such method,~aney nickel is used as a hydro-genation catalyst, and the reaction is carried out at a temperature of, ~or example, 20 to 60C and at a hydrogen pressure of, for example, 20 to 40 bar.
In the thus-produced diamines o the present inven-tion, the amino groups are in the same position as that previously occupied by the nitro groups and the R group is the same as that described ~or the R group in the alkyl-benzenes used as starting materials.
The diamines of the present invention are liquid at room temperature, show no tendency to crystallize and contain no undesirable monofunctional amine constituents.
The compounds according to the invention are therefore valuable chain lengthening agents for the production of Mo-2325 ~LZ~
polyurethanes by the isocyanate polyaddition process.
When the diamines of the present invention are used as chain lengthening agents, they are generally reacted with isocyanate prepolymers in known manner at an NCO/NH2 5 equivalent ratio of from 0.7:1 to 1.3:1, preferably from n . g 1 to 1.1:1. The isocyanate prepolymers used are known reaction products of the diisocyanates used in poly-urethane chemistry and subequivalent quantities of poly-hydroxyl compounds. The polyhydroxyl compounds which may 10 be used include polyhydroxypolyesters or polyhydro~y-polyethers having molecular weights o~ from 300 to 10,000, preferably from 1000 to 4000, and a hydro~yl functionality ~or average hydroxyl functionality when mixtures of poly-hydroxyl compounds are used) of from 2 to ~, preferably 15 from 2 to 3. The diamines of the present invention may also be used in a one shot process for the production of polyurethanes by adding them to a polyhydroxyl compound or a mixture o polyhydroxyl compounds (of the type described above~ and then reacting this mi~ture with known poly-20 isocyanates at an equivalent ratio of isocyanate groupsto isocyanate-reactive groups rnaintained within the range of about 0.8:1 to 1.2:1, preferably 1:1. Such a one-shot process may be carried out with the diamines of the present invention because the polyureas obtained also 25 have no tende~cy to crystallize so that such a one-shot process is not accompanied by the unwanted separation of polyureas. The diamines of the present invention may also be used as chain lengthening agents in such processes where any of a variety of known auxiliary agents and addi-30 tives are used. For example, polyurethane-polyurea foams may be produced with the aid of known blowing agents.
The Examples which follow serve to illustrate the present invention. Percentages given are percentages by weight unless otherwise indicated. Ready-made TLC plates Mo-2325 :~L2~3'7~
(silica gel 60F-254.of Merck AG) were used for the thin layer chromatographic investigations.
EXAMPLES
Example 1 A homologous mixture of linear alkylbenzenes in which the alkyl chains had a length of 10 to 13 C~.atoms, with an average length of about 12 C-atoms, was used in this Example. The temperature at which the homologous mixture boiled (according to ASTM D 86) at 1013 mbar was 10 in the temperature ranqe of about 233-313C. About 50 volume percent had distilled over betw~en 283 and 296 C. The product obtained was a reaction product of benzene with a mixture of linear C10-Cl3 olefins.
la) Nitration of the alkyl benzene mixture:
A mixture of 1136 ml of 98% nitric acid and 1584 ml o~ 96~ sul~uric acid was introduced dropwise with cooling into 1.97 kg o the above-described alkyl-benzene mixture at a rate such that the reaction temperature was maintained at 10 to 15C. After addition of the acids, the r~:action mixture was stirred for 3 hours at 25 to 30C. The organic phase was subsequently pourecl onto 10 kg of ice, washed with sodium bicarbonate solution until it was neutral and washed again with water. The srgan-ic phase was separated and substantially freed from any residue of water by centrifuying. The liquid dinitroalkyl benzene mixture obtained was used in the next reaction stage without further purifica-tion.
Yield: 2.7 kg; N02 content:- 27.5% (theoretical:
27.4~). No residues of mononitro compounds could be detected by thin layer chromatographic investi-gations (diluent 90 parts by weight petroleum ether/
lO.parts by weight ether).
Mo-2325 3'~L~
lb) Hydrogenation of the dinitroalkyl benzene mixture:
672 g of the dinitro compound prepared in la) were dissolved in 1700 ml of ethanol in a stirrer auto-clave. 70 g of Raney nickel were added. Stirrin~
was continued at 40C and 20 to 40 bar of hydrogen pressure until absorption of hydrogen had been completed. The pressure was then released, the reaction mixture was filt~red to remove the catalyst, and the ethanol was distilled off. 550 g of a crude amine mixture were obtained. The crude amine mix-ture had a nitrogen content of 10.06% (theoretical:
10.1~). 200 g of the crude amine mixture were distilled at reduced pressure. 167 g of diamine mixture (83.5% yield) were obtained as a fraction boiling at 185 to 20~C/2.1 mbar.
Anal~ is (%):
C H N
Found: 78~6 11.5 10.0 Theoretical: 78.3 11.6 10.1 20 (based on C18H32N2) Example 2 (Comparison Examp~.e) 2a) Nitration of dodecylbenzene:
Dinitrododecylbenzene was prepared according to Example V of US Patent 2,934,571. The crude product had an NO2 content of only 18.6 wt %. The product obtained after distillation had an NO2 content of 20.0 wt %. Thin layer chromatographic investi~ation indicated the presence of considerable' amounts of mononitro compounds, which may be de-duced from the a~oresaid low NO2 content.
2b) Hydrogenation o~ the'product of nitration:
The nitro compound produced in 2a) was converted in-to the corresponding amino compound by hydrogenation according to Example V of US Patent No. 2,986,576.
Mo-2325 73~
Analysis (%):
C H N
Found: 8104 12.1 7.0 Theoretical: 78.3 11.5 10.1 5 (based on Cl~H32N2) Example 3 2000 g of a linear polypropylene glycol ether (molec-ular weight 2000, OH number: 56) and 336 g of 1,6-diiso-cyanato-hexane were heated together to about 90C and 10 maintained at this temperature until an isocyanate content of about 3.35% was obtained. 500 g o this isocyanate prepolymer were briefly degasified at about 55C and mixed within 30 seconds with 53 g of the diamine mixture of Example lb). After a casting time of 4,to 5 minutes, 15 the sample in the mold (heated to 100C) was removed after about 1.5 hours. A flexible elastomer having an elasti-city of about 28~ (Shore A 40) was obtained after 24 hours' tempering at 110C.
Example 4 (Comparison E~ample) 500 g of the isocyanate prepc>lymer described in Example 3 and 53 g o the amine mixture rom Example 2 were combined in the manner described in Example 3. The product obtained was merely a liquid having a viscosity of 15,Q00 mPa.s/20C.
Mo-2325
Mo-2325 LeA 20,830 DIP~lINES AND A PROCESS
FOR THEI~ ~RE~AR~ION
BACKGROUND OF THE INVENTION
_ This invention relates to alkyl-substituted phenyl-ene diamines in the form of homologous or isomeric mix-tures and a process for their preparation. These dia-mines are useful as chain lengthening agents in the pro-duction of polyurethanes.
Aromatic diamines are a known class of compounds.
The simplest representatives of this class of compounds (i.e. the isomeric phenylene and tolylene diamines) are crystalline substances at room temperature. Because of this crystallinity, they have not been usRd to any signi-ficant extent as chain lengthening agents for the produc-tion of polyurethanes.
The preparation o~ long-chain dinitroalkylbenzenes is described in US Patent 2,934,571. According to US
Patent 2,986,576, such compounds may be converted into the corresponding diamines. The alkylbenzenes used as starting material in the examples of US Patent 2,934,571 are largely compounds characterized by a branch-chained oligopropylene side chain. In US 2,934,571, however, a special process for nitrat;ng these hydrocarbons is taught since conventional processes o nitration appear to have failed to nitrate the exemplified hydrocarbons to the corresponding dinitroalkylbenzenes. In spite of the elaborate process described in US Patent 2,934,571 ~in which sulfuric acid containing sulfur trioxide is used) it has been found that the end products contain troublesome residues of mononitro compounds. Further reaction of this disclosed nitration product to produce diamines inevitably leads to diamines containing an , ~o-2325 ~ ,, ,,,:
3~ .
undesirable amount of monoamines. Such a mixture of these ~diamines is not very useful as a chain lengthening agent in the production of polyurethanes. Consequently, the products of the above-described process have not been used 5 on a commercial scale by those in the art of polyurethane chemistry.
SUMMARY OF TEE rNVENTION
It is an object of the present invention to provide simple aromatic diamines, i.e. diamines having a single 10 aromatic nucleus and two aromatically bound primary amino groups.
It is also an object of the present invention to provide simple aromatic diamines which are liquid at room temperature and show no tendency to crystallize at room 15 temperature.
It is another object o the present invention to provide simple aromatic diamines which arè liquid at room temperature and which are substantially free o undesir-able monoamines.
It is a further object of the present invention to provide simple aromatic diamines which are liquid at room temp~rature and which may be used as reactants in the production of polyisocyanate addition products.
It is yet another object of the present invention 25 to provide a simple process for the production of simple aromatic diamines which are liquid at room t~mper~ture.
These and other objects which will be apparent to those skilled in the art are accomplished by nitrating and hydrogenating a hydrocarbon ~aving a boiling range of 30 270-330C which hydrocarbon corresponds to the formula R
~`
.
Mo-2325 ~2~3'1~
in which R represents a saturated, straight-chained ali-phatic hydrocarbon group having 8-15 carbon atoms.
The thus-produced diamine is a mixture of homologues and isomers of diamines corresponding-to the formula R
H2N ~ NH2 in which R is as defined above.
DETAILED DESCRIPTION OF TH~ INVENTION
The present invention relates to diamines correspond-ing to the formula:
R
H2N ~ ~ NH2 15 in which R denotes a saturated, straight-chained, alipha-tic hydrocarbon group having 8 to 15 carbon atoms.
These diamines are mixtures of homologues and isomers of the diamines corresponding to this formula. Such diamines are obtained by dinitration, ollowed by hydrogenation of 20 the nitro groups, of hydrocarbons corresponding to the formula:
R
in which R is as defined above. These hydrocarbons have a boiling range according to ASTM D 86 of 10-50C within the temperature range of from 270 C to ioo~c at 1013 mbar.
This invention also pr.ovides a process for the preparation of such diarnines in which a mixture of homo-Mo-2325.
?73~
logues and isomers of the above-described hydrocarbons is converted by nitration in known manner into dinitro com-pounds corresponding to the formula:
R
02N~} N02 10 and these dinitro compounds are subsequently hydrogenated to orm the corresponding diamines in known manner.
The diamines thus-produced are particularly useful as chain lengthening agents for the production of poly-urethanes by the isocyanate polyaddition process.
The starting materials used in the process of the present invention are mixtures of alkylbenzenes corre-sponding to the formula:
in which R represents a saturated, straight-chained ali-phatic hydrocarbon group having 8-15 (preferably 10-13) carbon atoms.
25 These alkylbenzenes are in the form of a mixture of homo-logues and isomers, which have a boiling range (according to ASTM D 86) of 10-50 C, preferably 20-30 C within the Semperature range of from 270 C to 330 C at 1013 mbar.
It is preferred that the alkylenebenzene mixture be such that at least 30 volume percent boils at a tempera-~ure below the middle of the boiling range and at least 30 volume percent boils at a temperature above the middle of the boiling range.
Mo-2325 ~ 2V~
The preparation of such alkylbenzene mixtures may be carried out by techniques known to those skilled in the art. ~ne such procedure is alkylation of benzene with appropriate commercial linear olefin mixtures.
5 Suitable linear olefin mixtures include commercial oligo-ethylene mixtures,other linear oligoolefins and commercial linear alkyl chloride mixtures such as those described, for example, in Kirk-Othmer, Encyclopedia of Chemical Technology, third edition, Vol. 2, (1978), pages 50 to 61.
In the process of the present invention, conversion o the alkylbenzenes into the corresponding dinitro compounds may be carried out by known nitration techniques.
In one such method, 2 to 3 mol of concentrated nitric acid are added for each mol of alkylbenæene with the 15 temperature being maintained at 10-30C. The nitric acid used may be in the form o a mixture with concentrated sul~uric acid (nitrating acid). 95~ of all the nitro groups in the alkyl-substituted dinitrobenz~nes obtained by this proces.s are determined by nuclear resonance 20 measurements (NMR)~ to be in the meta-position with respect to each other. About 10 to 30 wt ~ of the dini-trated alkylbenzenes should be l-alkyl-2,6-dinitrobenzenes and about 70 to 90 wt % should be 1-alkyl-2,4-dinitro-benzenes. This distribution of isomers is not, however, 25 essential to the invention. It would he equally possihle, for example, to carry out the next stage of the process of the present invention with dinitrated a~.kylbenzenes in which the above-mentioned isomers are present in different quan-titative proportions. For example, the .nitrobenzene could 30 be a 1-alkyl-2,4-dinitrobenzene fr~e from the 2,6-isomer.
Such a dinitrobenzene may be obtained, for example, by a two-stage nitration of an alkylbenzene in which the 1-alkyl-4-nitrobenzene obtained as an intermediate stage is Mo-2325 Z~3~
~ (, first separated from the nitration product an~ the~ di-nitrated before hydrogenation i~ be~un.
Use of the alkyl benzene mixtures required in the present invention as starting material yields dinitroalkyl-5 benzene mixtures in which virtually no troublesome mono-nitro constituents are present. The absence of such mono-nitro constituents may be confirmed by determination of the nitro group content and by thin layer chromatographic investigations of the products of nitration. These 10 dinitroalkyl benzene mixtures are particularly suitable for direct conversion to the diamines of the present invention since they require no elaborate methods of purification ~e.g. removal of mononitro compounds by distillation under speciic conditions). Such purifica-15 tion procedures are generally undesirable because aromaticnitro compounds readily decompose in the presence of heat.
The ne~t stage o the process of th~ present inven-tion is hydrogenation of the nitro groups to the corre-sponding primary amino groups. This hydrogenation may be 20 carried out by techniques known to those in the art. In one such method,~aney nickel is used as a hydro-genation catalyst, and the reaction is carried out at a temperature of, ~or example, 20 to 60C and at a hydrogen pressure of, for example, 20 to 40 bar.
In the thus-produced diamines o the present inven-tion, the amino groups are in the same position as that previously occupied by the nitro groups and the R group is the same as that described ~or the R group in the alkyl-benzenes used as starting materials.
The diamines of the present invention are liquid at room temperature, show no tendency to crystallize and contain no undesirable monofunctional amine constituents.
The compounds according to the invention are therefore valuable chain lengthening agents for the production of Mo-2325 ~LZ~
polyurethanes by the isocyanate polyaddition process.
When the diamines of the present invention are used as chain lengthening agents, they are generally reacted with isocyanate prepolymers in known manner at an NCO/NH2 5 equivalent ratio of from 0.7:1 to 1.3:1, preferably from n . g 1 to 1.1:1. The isocyanate prepolymers used are known reaction products of the diisocyanates used in poly-urethane chemistry and subequivalent quantities of poly-hydroxyl compounds. The polyhydroxyl compounds which may 10 be used include polyhydroxypolyesters or polyhydro~y-polyethers having molecular weights o~ from 300 to 10,000, preferably from 1000 to 4000, and a hydro~yl functionality ~or average hydroxyl functionality when mixtures of poly-hydroxyl compounds are used) of from 2 to ~, preferably 15 from 2 to 3. The diamines of the present invention may also be used in a one shot process for the production of polyurethanes by adding them to a polyhydroxyl compound or a mixture o polyhydroxyl compounds (of the type described above~ and then reacting this mi~ture with known poly-20 isocyanates at an equivalent ratio of isocyanate groupsto isocyanate-reactive groups rnaintained within the range of about 0.8:1 to 1.2:1, preferably 1:1. Such a one-shot process may be carried out with the diamines of the present invention because the polyureas obtained also 25 have no tende~cy to crystallize so that such a one-shot process is not accompanied by the unwanted separation of polyureas. The diamines of the present invention may also be used as chain lengthening agents in such processes where any of a variety of known auxiliary agents and addi-30 tives are used. For example, polyurethane-polyurea foams may be produced with the aid of known blowing agents.
The Examples which follow serve to illustrate the present invention. Percentages given are percentages by weight unless otherwise indicated. Ready-made TLC plates Mo-2325 :~L2~3'7~
(silica gel 60F-254.of Merck AG) were used for the thin layer chromatographic investigations.
EXAMPLES
Example 1 A homologous mixture of linear alkylbenzenes in which the alkyl chains had a length of 10 to 13 C~.atoms, with an average length of about 12 C-atoms, was used in this Example. The temperature at which the homologous mixture boiled (according to ASTM D 86) at 1013 mbar was 10 in the temperature ranqe of about 233-313C. About 50 volume percent had distilled over betw~en 283 and 296 C. The product obtained was a reaction product of benzene with a mixture of linear C10-Cl3 olefins.
la) Nitration of the alkyl benzene mixture:
A mixture of 1136 ml of 98% nitric acid and 1584 ml o~ 96~ sul~uric acid was introduced dropwise with cooling into 1.97 kg o the above-described alkyl-benzene mixture at a rate such that the reaction temperature was maintained at 10 to 15C. After addition of the acids, the r~:action mixture was stirred for 3 hours at 25 to 30C. The organic phase was subsequently pourecl onto 10 kg of ice, washed with sodium bicarbonate solution until it was neutral and washed again with water. The srgan-ic phase was separated and substantially freed from any residue of water by centrifuying. The liquid dinitroalkyl benzene mixture obtained was used in the next reaction stage without further purifica-tion.
Yield: 2.7 kg; N02 content:- 27.5% (theoretical:
27.4~). No residues of mononitro compounds could be detected by thin layer chromatographic investi-gations (diluent 90 parts by weight petroleum ether/
lO.parts by weight ether).
Mo-2325 3'~L~
lb) Hydrogenation of the dinitroalkyl benzene mixture:
672 g of the dinitro compound prepared in la) were dissolved in 1700 ml of ethanol in a stirrer auto-clave. 70 g of Raney nickel were added. Stirrin~
was continued at 40C and 20 to 40 bar of hydrogen pressure until absorption of hydrogen had been completed. The pressure was then released, the reaction mixture was filt~red to remove the catalyst, and the ethanol was distilled off. 550 g of a crude amine mixture were obtained. The crude amine mix-ture had a nitrogen content of 10.06% (theoretical:
10.1~). 200 g of the crude amine mixture were distilled at reduced pressure. 167 g of diamine mixture (83.5% yield) were obtained as a fraction boiling at 185 to 20~C/2.1 mbar.
Anal~ is (%):
C H N
Found: 78~6 11.5 10.0 Theoretical: 78.3 11.6 10.1 20 (based on C18H32N2) Example 2 (Comparison Examp~.e) 2a) Nitration of dodecylbenzene:
Dinitrododecylbenzene was prepared according to Example V of US Patent 2,934,571. The crude product had an NO2 content of only 18.6 wt %. The product obtained after distillation had an NO2 content of 20.0 wt %. Thin layer chromatographic investi~ation indicated the presence of considerable' amounts of mononitro compounds, which may be de-duced from the a~oresaid low NO2 content.
2b) Hydrogenation o~ the'product of nitration:
The nitro compound produced in 2a) was converted in-to the corresponding amino compound by hydrogenation according to Example V of US Patent No. 2,986,576.
Mo-2325 73~
Analysis (%):
C H N
Found: 8104 12.1 7.0 Theoretical: 78.3 11.5 10.1 5 (based on Cl~H32N2) Example 3 2000 g of a linear polypropylene glycol ether (molec-ular weight 2000, OH number: 56) and 336 g of 1,6-diiso-cyanato-hexane were heated together to about 90C and 10 maintained at this temperature until an isocyanate content of about 3.35% was obtained. 500 g o this isocyanate prepolymer were briefly degasified at about 55C and mixed within 30 seconds with 53 g of the diamine mixture of Example lb). After a casting time of 4,to 5 minutes, 15 the sample in the mold (heated to 100C) was removed after about 1.5 hours. A flexible elastomer having an elasti-city of about 28~ (Shore A 40) was obtained after 24 hours' tempering at 110C.
Example 4 (Comparison E~ample) 500 g of the isocyanate prepc>lymer described in Example 3 and 53 g o the amine mixture rom Example 2 were combined in the manner described in Example 3. The product obtained was merely a liquid having a viscosity of 15,Q00 mPa.s/20C.
Mo-2325
Claims (3)
1. A mixture of homologues and isomers of diamines corresponding to the formula in which R denotes a saturated, straight-chained aliphatic hydrocarbon group having 8-15 carbon atoms which mixture has been prepared by a) dinitrating a hydrocarbon corresponding to the general formula in the form of a mixture of homologues and isomers which hydrocarbons have a boiling range according to ASTMD 86 of 10-50°C at 1013 mbar within the temperature range of from 270°C to 330°C; and (b) hydrogenating the nitro groups present in the product of (a).
2. A process for the production of a mixture of homologues and isomers of diamines corresponding to the general formula in which R represents a saturated, straight-chained ali-phatic hydrocarbon group having 8-15 carbon atoms comprising:
(a) nitrating a hydrocarbon having a boiling range of 270-330°C (1013 mbar) corresponding to the formula to form a dinitro compound corresponding to the formula and (b) hydrogenating the thus-formed dinitro compound to form the corresponding diamine.
(a) nitrating a hydrocarbon having a boiling range of 270-330°C (1013 mbar) corresponding to the formula to form a dinitro compound corresponding to the formula and (b) hydrogenating the thus-formed dinitro compound to form the corresponding diamine.
3. A chain lengthening agent useful in the produc-tion of polyurethanes by the isocyanate polyaddition pro-cess which is a mixture of homologues and isomers of diamines corresponding to the general formula in which R represents a saturated straight-chained ali-phatic hydrocarbon group having 8-15 carbon atoms which has been produced by nitration and hydrogenation of a hydrocarbon corresponding to the formula which hydrocarbon has a boiling range of 270-330°C (1013 mbar).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3105362.9 | 1981-02-13 | ||
| DE19813105362 DE3105362A1 (en) | 1981-02-13 | 1981-02-13 | NEW DIAMINES, A METHOD FOR THE PRODUCTION THEREOF, AND THEIR USE AS A CHAIN EXTENSION AGENT IN THE PRODUCTION OF POLYURETHANE PLASTICS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1207340A true CA1207340A (en) | 1986-07-08 |
Family
ID=6124842
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000395138A Expired CA1207340A (en) | 1981-02-13 | 1982-01-28 | Diamines and a process for their preparation |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0058335B1 (en) |
| JP (1) | JPS57150644A (en) |
| CA (1) | CA1207340A (en) |
| DE (2) | DE3105362A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5786438A (en) * | 1996-04-11 | 1998-07-28 | Bayer Aktiengesellschaft | Mixtures of cycloaliphatic diisocyanates, a process for their preparation and their use for the production of polyisocyanate addition products |
| US5837796A (en) * | 1996-07-10 | 1998-11-17 | Bayer Aktiengesellschaft | Polyisocyanates containing isocyanurate groups and prepared by trimerizing alkyl-substituted cycloaliphatic diisocyanates |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3833440A1 (en) * | 1988-10-01 | 1990-04-05 | Hoechst Ag | POLYHARM AND FILM MADE OF AT LEAST ONE MONOMOLECULAR LAYER OF A POLYHARM |
| CA2020500A1 (en) * | 1989-07-28 | 1991-01-29 | Robson Mafoti | Process for the preparation of polyurea-polyurethane elastomers |
| KR100542131B1 (en) * | 2003-01-29 | 2006-01-11 | 김용배 | Polyimide resin for non-rubbing vertically alignment materials and preparation method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2934571A (en) * | 1958-02-06 | 1960-04-26 | Atlantic Refining Co | Dinitrated aromatic compounds and method for their production |
| BE575369A (en) * | 1958-02-06 | |||
| US4218543A (en) * | 1976-05-21 | 1980-08-19 | Bayer Aktiengesellschaft | Rim process for the production of elastic moldings |
| JPS5323936A (en) * | 1976-08-12 | 1978-03-06 | Mitsui Toatsu Chem Inc | Preparation of phenylenediamines |
-
1981
- 1981-02-13 DE DE19813105362 patent/DE3105362A1/en not_active Withdrawn
-
1982
- 1982-01-28 CA CA000395138A patent/CA1207340A/en not_active Expired
- 1982-02-02 EP EP82100699A patent/EP0058335B1/en not_active Expired
- 1982-02-02 DE DE8282100699T patent/DE3264352D1/en not_active Expired
- 1982-02-12 JP JP57019864A patent/JPS57150644A/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5786438A (en) * | 1996-04-11 | 1998-07-28 | Bayer Aktiengesellschaft | Mixtures of cycloaliphatic diisocyanates, a process for their preparation and their use for the production of polyisocyanate addition products |
| US5837796A (en) * | 1996-07-10 | 1998-11-17 | Bayer Aktiengesellschaft | Polyisocyanates containing isocyanurate groups and prepared by trimerizing alkyl-substituted cycloaliphatic diisocyanates |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3264352D1 (en) | 1985-08-01 |
| EP0058335B1 (en) | 1985-06-26 |
| EP0058335A3 (en) | 1983-10-26 |
| JPH0216292B2 (en) | 1990-04-16 |
| DE3105362A1 (en) | 1982-09-02 |
| EP0058335A2 (en) | 1982-08-25 |
| JPS57150644A (en) | 1982-09-17 |
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