CA1216858A - Diisocyanates, diisocyanate mixtures and a process for their production - Google Patents
Diisocyanates, diisocyanate mixtures and a process for their productionInfo
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- CA1216858A CA1216858A CA000442676A CA442676A CA1216858A CA 1216858 A CA1216858 A CA 1216858A CA 000442676 A CA000442676 A CA 000442676A CA 442676 A CA442676 A CA 442676A CA 1216858 A CA1216858 A CA 1216858A
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- Prior art keywords
- diisocyanate
- carbon atoms
- diisocyanates
- hydrogen
- represent
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-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C265/00—Derivatives of isocyanic acid
- C07C265/12—Derivatives of isocyanic acid having isocyanate 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
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
- C08G18/72—Polyisocyanates or polyisothiocyanates
- C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
-
- 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
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
- C08G18/72—Polyisocyanates or polyisothiocyanates
- C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
- C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Polyurethanes Or Polyureas (AREA)
Abstract
DIISOCYANATES, DIISOCYANATE MIXTURES
AND A PROCESS FOR THEIR PRODUCTION
ABSTRACT OF THE DISCLOSURE
Diisocyanates and isomeric mixtures of diiso-cyanates corresponding to the formula in which R1, R2, m and n are as defined herein, are produced by phosgenating diamines corresponding to the formula
AND A PROCESS FOR THEIR PRODUCTION
ABSTRACT OF THE DISCLOSURE
Diisocyanates and isomeric mixtures of diiso-cyanates corresponding to the formula in which R1, R2, m and n are as defined herein, are produced by phosgenating diamines corresponding to the formula
Description
` ~Z~8S~
Mo-2526 LeA 22,007 ` DIISOCYANATES, DIISOCYANATE MIXTURES
AND A PROCESS FOR THEIR PRODUCTION
, BACKGROUND OF THE INVENTION
__ This invention relates to isocyanatobenzyl-5 cyclohexylisocyanates which may be present as isomer ~ mixtures and are alkyl-substituted at ~he aromatic ring.
J The present invention also relates to a process for the production of such isocyanates.
Asymmetric diisocyanates which have one aro-l0 matically and one cycloaliphatically bound isocyanate ~ group would be particularly suitable for the production ,~ of polyurethane plastics by the prepolymer process due to the significantly different reactivity of the iso-cyanate groups. The more highly reactive, aromatically ~; 15 bound isocyanate group would react to form the NCO
prepolymer which would then be converted into a high molecular weight polyurethane in a second reaction stage.
Such asymmetric diisocyanates would also be 20 suitable for the production of modified diisocyanates such as uretdione diisocyanates. The more highly reactive isocyanate group would be reacted off with dimerization in a first reaction stage and a diisocya-nate containing uretdione groups would be obtained.
25 This uretdione diisocyanate could then be further reacted with compounds having groups reactive to iso-cyanate groups.
U.S. Patent 3,663,514 describes one such diiso-cyanate, namely 4-(4-isocyanatobenzyl)-cyclohexyliso-30 cyanate. However, use of this disclosed diisocyanate to any great extent has been limited due to the fact that the diamine on which the diisocyanate is based can only be obtained in yields of less than 35% of the theoretical yield. These poor yields are attributable 35 to asy~metric nuclear hydrogenation. The pure asymmetric Mo-2526 LeA 22 007-US ~æ
~168S~
.
Mo-2526 LeA 22,007 ` DIISOCYANATES, DIISOCYANATE MIXTURES
AND A PROCESS FOR THEIR PRODUCTION
, BACKGROUND OF THE INVENTION
__ This invention relates to isocyanatobenzyl-5 cyclohexylisocyanates which may be present as isomer ~ mixtures and are alkyl-substituted at ~he aromatic ring.
J The present invention also relates to a process for the production of such isocyanates.
Asymmetric diisocyanates which have one aro-l0 matically and one cycloaliphatically bound isocyanate ~ group would be particularly suitable for the production ,~ of polyurethane plastics by the prepolymer process due to the significantly different reactivity of the iso-cyanate groups. The more highly reactive, aromatically ~; 15 bound isocyanate group would react to form the NCO
prepolymer which would then be converted into a high molecular weight polyurethane in a second reaction stage.
Such asymmetric diisocyanates would also be 20 suitable for the production of modified diisocyanates such as uretdione diisocyanates. The more highly reactive isocyanate group would be reacted off with dimerization in a first reaction stage and a diisocya-nate containing uretdione groups would be obtained.
25 This uretdione diisocyanate could then be further reacted with compounds having groups reactive to iso-cyanate groups.
U.S. Patent 3,663,514 describes one such diiso-cyanate, namely 4-(4-isocyanatobenzyl)-cyclohexyliso-30 cyanate. However, use of this disclosed diisocyanate to any great extent has been limited due to the fact that the diamine on which the diisocyanate is based can only be obtained in yields of less than 35% of the theoretical yield. These poor yields are attributable 35 to asy~metric nuclear hydrogenation. The pure asymmetric Mo-2526 LeA 22 007-US ~æ
~168S~
.
-2-diisocyanate can therefore only be obtained at consider-'~ able purification cost .
SUMMARY OF THE INVENTION
It is an object of the present inVention to provide new diisocyanates having aromatically and cyclo-aliphatically bound isocyanate groups.
It is also an object of the present invention ~ to provide liquid diisocyanates having aromatically and i~ cycloaliphatically bound isocyanate groups which have a ~ 10 low viscosity at room temperature.
,~ It is another object of the present invention to provide diisocyanates having aromatically and cyclo-',~ aliphatically bound isocyanate groups which are soluble ~ and compatible with hydroxyl group-containing compounds.
,~ 15 It is a further object of the present invention to provide diisocyanates having aromatically and cyclo-aliphatically bound isocyanate groups with a low content of unhydrogenated or perhydrogenated diisocyanates.
It is yet another object of the present inven-tion to provide a process for the production of diiso-cyanates having aromatically and cycloaliphatically bound isocyanate groups in high yield.
These and other objectswhich will be apparent to those skilled in the art are accomplished by phos-25 genating diamines or isomer mixtures of diamines cor-responding to the formula /R
(H2N)m ~ 2 ~ NH2 (NH2)n R
in which Rl, R , m and n are as defined below at a temperature of from -20 to 250C.
: Mo-2526 s~
; `! - 3--~ DETAILED DESCRIPTION OF THE INVENTION
"
l, The present invention provides diisocyanates '"J, which correspond to the formula: 1 '~3 ~F~
}~ (OCN)m ~ 2 ~ NCO
~ 2 ';A~ (NCO)n R
-. 5 in which l and R2 which may be the same or diferent each represent hydrogen or (optionally branched) , alkyl groups having from 1 to 12 carbon atoms, ~, provided that at least one of the radicals i 10 Rl and R2 represents an alkyl radical, and .l m and n each represent 0 or 1, provided that the total of m + n - 1 and when m or n = 0, the remaining free valency is saturated by hydrogen~
t~ ~ 15 These diisocyanates may be in the form of isomer mix-~ ~ tures and may be present in admixture with minor amounts }~` : of the corresponding perhydrogenated diisocyanates and/or ~: corresponding unhydrogenated aromatic diisocyanates.
This invention also provides a process for ~; 20 the production of such diisocyanates or diisocyanate mixtures, in which the aminobenzyl-cyclohexylamines ,~ on which the product diisocyanates are based and which t~ are optionally present as a position and/or stereo isomer mixture and optionally in admixture with minor quantities of the corresponding perhydrogenated diamines and/or the corresponding unhydrogenated aromatic diamines are phosgenated in a known manner at from -20 to +250C.
This invention further provides a process for the production of polyurethane plastics by the isocya~
nate-polyaddition process from the diisocyanates of the present invention.
''` .
~: Mo-2526 ~, ',`
.
i858 Startiny materials for the production of the diisocyanates of the present invention are diamines or ~ mixtures of position and/or stereoisomers of diamines I corresponding to the formula: R1 (H2N)m ~ CH2 ~ 2NH2 ~NH2)n R
in which Rll R2, m and n are as defined above. Preferred diamines are those in which Rl and/or R2 represents alkyl groups having from 1 to 4 ~arbon atoms and especially methyl groups.
The diamines or diamine mixtures which are used in the present invention are often mixtures in which minor quantities of the corresponding perhydrogenated diamines and/or with minor quantities of the correspond-ing unhydrogenated aromatic diamines are present. Theexpression "minor quantities" as used herein means that the proportion of perhydrogenated or unhydrogenated diamines is in each case a maximum of 15, preferably a maximum of S wt. %, based on total diamine mixture.
According to NMR spectroscopic findings, the main compo-nent or the main components of the diamines or diamine mixtures of the present invention (i.e., the amino-benzyl-cyclohexylamines) are almost exclusively asym-metric diamines of the specified structure in which the alkyl substituents are bonded to the aromatic ring.
The composition of the diisocyana~es or of the diiso-cyanate mixtures of this invention ~orresponds to the composition of the diamines or diamine mixtures used as starting material in the process of the present inven-tion.
The diamines to be used in the present inven-tion are preferably produced by partial nuclear hydro-genation of the alkyl-substituted diaminodiphenyl Mo-2526 ~2J1 6858 methanes on which they are based. These asymmetrically substituted diaminodiphenyl methanes may be obtained, for example by condensation of _- and/or ~~nikrobenzyl halides (particularly chlorides) with substituted anilines corresponding to the formula in which Rl and R2 are as defined above, and reduction of the nitro group to produce the primary amine and by subsequent transposition. Such a procedure is disclosed in Belgian Patent 864,533 and British Patent 1,567,114.
Depending upon whether pure _-nitrobenzyl halide or pure p-nitrobenzyl halide or mixtures of these isomers are used during the condensation reaction, the ratio of the 4,4'-diamino-3(,5)-(di)-alkyldiphenylmethanes to the 4,2'-diamino~3(,5)-(di)-alkyldiphenylmethanes corresponds substantially to the isomer ratio of _-nitrobenzyl halide to o-nitrobenzyl halide used in the condensation reaction. Only when monosubstituted anilines (R2 = H) are used are minor quantities (up to 5 wt. %, based on the total mixture) of 2,4'-diamino-3-alkyldiphenyl-methanes and/or of the corresponding 2,2'-isomers pro-duced.
The nuclear hydrogenation of the aromatic diamines may be carried out by methods known to those in the art (see U.S. Patent 2,511,028). In one such method, aromatic diamines are hydrogenated catalytical-ly with the addition of 3 mols of hydrogen per mol of diamine. The hydrogenation reaction is preferably interrupted after the consumption of 3 mols of hydrogen per mol of starting compound.
Mo-2526 -' ~2~6~S~
Hydrogenation is carri0d out at from 20 ~o 300~, preferably from 70 to 300C and most preerably from 120 to 250C under a pressure o~ from 20 to 300 ~ars, pre-ferably from 70 to 300 bars and mosk preferably rom 120 to 250 bars.
The hydrogenation reaction is generally carried out in the presence of from 0.1 to lO wt.%, preferably from 0.1 to l wt. % of a hydrogenation catalyst, based on catalytically active metal and on diamino compounds.
Suitable catalysts include, for example, elements of the VIII Secondary Group of the Periodic System of Elements which are optionally present on inert carriers (such as active carbon, silica gel and in particular aluminum oxide) or catalytically active inorganic compounds of these elements. Specific examples of appropriate cata-lysts are ruthenium, platinum, rhodium, nickel and/or cobalt in elementary or chemically bound form. Ruthen-ium or catalytically active ruthenium compounds are preferred. Examples of suitable ruthenium compounds include ruthenium dioxide, ruthenium tetroxide; barium perruthenite; sodium, potassium, silver, calcium or magnesium ruthenate; sodium perruthenate; ruthenium pentafluoride; ruthenium tetrafluoride hydrate and ruthenium trichloride. If a material is used as both carrier and catalyst, the metal content of the carrier catalyst is generally from l to lO wt. ~, preferably from l to 5 wt. %. The type and quantity of catalyst to be used is not essential to the present invention.
It is often appropriate to carry out the hydrogenation reaction in the presence of ammonia because a~monia suppresses undesired deamination reac-tions and the formation o~ secondary amines as ky-products. If ammonia i5 used, it may be used in quan-tities of from 0.1 to 30 wt. %, preferably from 5 to lO
wt. ~ (based on the starting materials to be hydrogen-ated).
Mo-25~6 ~6~S~
The hydrogenation reaction may be carried out without a solvent or in the presence of an inert sol-vent. Low-melting or liqu~d diamines are generally hydrogenated without using a solvent. High-melting diamines are generally hydrogenated in dissolved form.
Organic compounds which are inert under the reaction conditions and which have a low boiling point are suit-able as solvents. Bxamples of suitable solvents are alcohols such as methanol, ethanol, n-propanol and i_ propanol; ethers such as dioxane, tetrahydrofuran and diethyl ether; and hydrocarbons such as cyclohexane.
Hydrogenation may be carried out continuously in a reaction $ube or in a pressure boiler cascade. It is preferable, however, that hydrogenation be carried out discontinuously in a stirrer-equipped autoclave by charging the autoclave with catalyst, the substance to be hydrogenated and optionally with a solvent and repeatedly flushing with inert gas and optionally meter-ing in ammonia. Hydrogenation is then injected undPr pressure, the mixture is brought to reaction temperature and hydrogenation is carried out until the theoretically necessary quantity of hydrogen has been absorbed.
After the reaction mixture has been cooled and the catalyst has been separated, the hydrogenation product may be worked up by distillation.
The hydrogenation products are obtained in high yields. Mono-alkyl-substituted diamines may be produced in amounts which are more than 70% of the theoretical yield. Dialkyl-substituted diamines may be obtained in amounts of more than 90~ of the theoretical yield. Further, the hydrogenation products may be almost completely separated by distillation from unreacted aromatic diamines or from the perhydrogenated diamines which are produced as by-products. The hydro-genation products are generally stereoisomeric mixtures,optionally also position isomer mixtures which corres-Mo-2526 685~
pond substantially to the starting materials with respect to position isomerism. It is generally not necessary to separate the products into individual position and/or stereoisomers before using them as starting materials in the process of the present inven-tion because in this process isomer purity is not necessary. In fact, isomer mixtures are often desirable because they improve the properties of the product diisocyanates.
Materials which may be produced by the above-described hydrogenation process which are preferred starting materials in the process of the present inven-tion include: 4-(4-amino-3,5-dimethylbenzyl)-cyclo-hexylamine, 4-(4-amino-3,5-diethylbenzyl)-cyclohexyl-amine, 4-(4-amino-3,5-diisopropylbenzyl)-cyclohexyl-amine, 4-(4-amino-3-ethyl-5-methylbenzyl)-cyclohexyl-amine and isomer mixtures containing these diamines as essential components; 2-(4-amino-3,5-dimethylbenzyl)-cyclohexylamine, 2-(4-amino-3/5-diethylbenzyl)-cyclo-hexylamine, 2-(4-amino-3,5-diisopropylbenzyl)-cyclo-hexylamine, 2-(4-amino-3-ethyl-5-methylbenzyl)-cyclo-hexylamine and isomer mixtures containing these diamines as essential components; 4-(4-amino-3-methylbenzyl)-cyclohexylamine, 4-t4-amino-3-ethylbenzyl)-cyclohexyl-amine, 4-(4-amino-3-isopropylbenzene)-cyclohexylamine and mixtures thereof with other position isomers (for example the corresponding 2-(4-amino-3-alkylbenzyl)-cyclohexylamines and/or 4-(2-amino-3-alkylbenzyl)cyclo-hexylamines); 2-(4-amino-3-methylbenzyl)-cyclvhexyl-amine, 2-(4-amino-3-ethylbenzyl)-cyclohexylamine, 2-(4-amino-3-isopropylbenzyl)-cyclohexylamine and mixtures thereof with the corresponding 4-(4-amino-3-alkylbenzyl)- or 4-(2-amino-3-al~ylbenzyl)-cyclohexyl-amines.
When carrying out the process of the present invention for the production of the new diisocyanates, Mo-2526 ~6~S~
phosgenation of ~he abo~e-mentioned diamines or o the salts thereof may be carried out in accordance with known methods in the presence oF an inert organic sol-vent (see Houben-Weyl, Methoden der OrganiRchen Chemie, Georg Thieme Verlag, Stuttgart (1952), Volume 8, 4th edition, pages 120 et se~).
The hydrochlorides or ammonium carbamates which may be produced by saturation of the diamine solutions with gaseous hydrogen chloride or carbon dioxide are examples of preferred salts which may be phosgenated to produce the diisocyanates of the present invention.
In principle, other salts which are produced, for example by neutralization of the diamines with proton-releasing acids may also be phosgenated.
The selectivity of the phosgenation reaction is dependent upon the amine concentration and the phos-gene excess. The phosgene is preferably used in a high molar excess which generally amounts to from 100 to 2000%, preferably from 100 to 1000%. The diamine to be phosgenated is used in a considerably dilute form. The amine concentration (based on the total quantity of amine and solvent) generally amounts to 0.1 to 15 wt. %, preferably from 5 to 10 wt. %.
Any inert organic liquids or mixtures thereof which have a boiling point of from 60 to 250C may be used as solvent in the phosgenation process. Examples of appropriate solvents include halogenated hydrocarbons, aromatic compounds, hydroaromatic compounds and chlorine compounds thereof. The following are mentioned as specific examples of suitable solvents: xylene, mesi-tylene, chlorobenzene, dichlorobenzenei trichlorobenzene, chlvronaphthalene and dichloroethane.
The reaction may be carried out either in one stage by hot phosgenation at a temperature of from 100 to 25~C, or in two stages by cold/hot phosgenation at Mo-2526 a temperature of from -20 to 250C under normal pressure, When free amines are used as the starting compound (base phosgenation), ammonium carbamic acid chloride i8 ~irst produced at a temperature of from -20 to ~60C. This ammonium carbamic acid chloride further reacts with phos-gene to produce the diisocyanate at a temperature o~
from 20 to 250C. The products are generally purified after de-phosgenation by evaporating the solvent and by subsequent distillation under reduced pressure.
The products of the process of the present invention, i.e., the new diisocyanates of this invention are produced in high yields as colorless, low viscosity liquids. These diisocyanates are valuable synthesis components in the production of polyurethane plastics by the isocyanate-polyaddition process. The position and/or stereoisomerism of the new diisocyanates corres-ponds to the isomerism of the diamines which are used as starting materials for the phosgenation process.
It is not generally necessary to separate the mixtures produced by the process of the present invention into individual position and/or stereoisomers because the products may be used directly in the production of poly-urethanes. The new diisocyanates of this invention are particularly advantageous for the production of poly-urethane lacquers, polyurethane elastomers and polyure-thane foams. Such polyurethanes may be produced by processes known to those skilled in the art by using the diisocyanates of the present invention instead of or together with the polyisocyanates which have been used by those in the art. The new diisocyanates or diisocyanate mixtures of the present invention are particularly advantageous in the production of poly-urethane plastics by the prepolymer process.
The following examples illu~.trate the present invention. All percentages relate to percent by weight, Mo-2526 ~3 6~S~
unless otherwise indicated. The analysis of the isomer distribution of the intermediate and end products was carried out by yas chromatography.
EXAMPLES
Example 1 la) 250 g (1.04 mols) of 4,4'-diamino-3-ethyl-5-methyl-diphenylmethane and 25 g of ruthenium-aluminum oxide carrier catalyst (5~ of Ru on A12O3) were intro-duced into a 0.7 liter stirrer-equipped autoclave.
After repeated flushing with nitrogen and hydrogen, 25 g of ammonia were introduced with mixing. The mixture was heated with stirring to 150-155C and hydrogenated under 200 bars until 3.12 mols of hydrogen had been absorbed. Thereafter, the mixture was allowed to cool, the autoclave pressure was relaxed and the crude product dissolved in methanol. The catalyst was filtered and washed with methanol. The organic solutions were com-bined. After evaporation of the solvent, the product was subjected to a flash-distillation and then distilled by fractionation. 220 g of diamine having a boiling point of from 125 to 130C/0.05 mbar were obtained.
According to gas chromatographic findings, this diamine was 97.2% 4-(4-amino-3-ethyl-5-methylbenzyl)-cyclo-hexylamine, 0.8% 4,4'-diamino-3-ethyl-5-methyldicyclo-hexylmethane and 2.0~ unreacted starting material andunknown diamine.
lb) 250 g of phosgene were dissolved in 700 ml of chlorobenzene at from -5 to 8C. A solution of 123 g of the diamine produced in Example la) in 700 ml of chlorobenzene was added to the phosgene solution drop-wise with stirring. A suspension was produced which heated to 20C. The mixture was heated to 130C as 100 g/h of phosgene was introduced. The solids dis-solved and the solution was boi~ed for an additional 2 Mo-2526 ~l~1tii8S~3 hours under reflux. Thereafter, the addition o phos-gene was completed. Excess phosgene was blown out with nitrogen and the crude product was purified by di~til-lation. 139 g (96% of the theoretical yield) of 4-(4-isocyanato-3-ethyl~5-methylbenzyl)-cyclohexyl isocyanate were produced. The product had the following properties:
Boiling point: 133 to 135~C/0.05 mbar;
NCO value: 28.3%;
Viscosity. 110 mPa.s~25C;
Content of hydrolyzable chlorine: 0.02~.
Example 2 2a) 250 g (1.11 mols) of 4,4'-diamino-3,5-dimethyldiphenylmethane were hydrogenated in the presence of 25 g of ruthenium-aluminum oxide carrier catalyst and 25 g of ammonia at 140C and under 200 bars by the same procedure described in Example la). This hydrogenation continued until 3.3 mols of hydrogen had reacted off.
After purifying by flash distillation and fine distilla-tion at from 150 to 155C/0.1 to 0.2 mbar, 200 g of pro-duct were obtained. According to gas chromatographicanalysis, the product was 97.4% 4-(4-amino-3,5-dimethyl-benzyl~-cyclohexylamine, 2.1% 4,4'-diamino-3,5-dimethyl-dicyclohexylmethane and 0.5% unreacted starting material.
2b) 116 g of the diamine mixture produced in Example 2a~ dissolved in 700 ml of chlorobenzene were added dropwise with intensive stirring into a solution of 200 g of phosgene in 700 ml of anhydrous chloro-benzene at from 0 to 8C. The resulting suspension was heated to 120C with the introduction of 100 g/h of phosgene. During this procedure, the solids slowly dissolved and a clear solution resulted at 65C.
After phosgenating for two hours at 120C, the solution was de-phosgenated and the crude product was purified by distillation. 121 g (87.5% of the theoretical yield) of 4-(4-isocyanato-3,5-dimethylbenzyl)-cyclo-Mo-2526 ~6~
hexyl isocyanate having a boiling point of from 138 to 141C/0.1 mbar, an NCO content of 29.5% and a viscosity oE 140 mPa.s/25C were obtained.
~xample 3 3a) A 0.7 liter stirrer-equipped autcclave was charged with 250 g (0.98 mols) of 4,4'-diamino 3,5-diethyldiphenylmethane and 25 g of ruthenium-aluminum oxide carrier catalyst (5% of Ru on A12O3). The auto-clave was then flushed with nitrogen and 25 g of ammonia were metered in. Thereafter, the mixture was hydrogenated at 140C and under 200 bars until 3 mols of hydrogen had been consumed. The autoclave was allowed to cool, the pressure therein was relaxed, the product was taken up in methanol and the catalyst was filtered. The solvent was then drawn off and the hydrogenated diamine was purified by flash and fine distillation at from 136 to 140C/0.1 mbar. 170 g of diamine having a content of 95.8% 4-~4-amino-3,5-di-ethylbenzyl)-cyclohexylamine, 3,3% of perhydrogenated starting diamine and 0.9~ of unreacted starting material were obtained (according to gas chromato-graphic analysis).
3b) 200 g of phosgene were dissolved in 700 ml of anhydrous chlorobenzene. A solution of 130 g of diamine from ~xample 3a) in 700 ml of dry chlorobenzene was added dropwise to the phosgene solution with stir-ring and cooling. A dispersion which was difficult to stir and which changed into a clear solution during heating with the introduction of phosgene at 80C
formed. The solution was boiled for 2 hours under reflux, the addition of phosgene was completed, the solution was de-phosgenated and the crude product was distilled at 135C/O.9S mbar. 134 g (90% of the theoretical yield) of 4-(4 isocyanato-3,5-diethyl-benzyl)-cyclohexylisocyanate, were obtained having an NCO content of 27.0% and a viscosity of 90 mPa.s/2SC.
Mo-2526 ~l~216~
Example 4 4a) 250 g (0.89 mols) of 4,4'-diamino-3,5-diisopropyl-diphenylmethane were hydrogena~ed in the presence of 25 g of xuthenium-aluminum oxide carrier catalyst (5% of Ru on A12O3) and 25 g of ammonia at 140C/200 bars by the same procedure as that used in Example la), until 2.7 mols of hydrogen had been absorbed. After flash distillation, the product was subjected to fractional distillation. During this procedure, 214 g of 4-(4-amino-3,5-diisopropylbenzyl)-cyclohexylamine were produced in the main fraction.
According to gas chromatographic analysis, 0.5% of perhydrogenated diamine and 0.5~ of starting diamine were present in the product diamine.
4b) A solution of 200 g of phosgene in 700 ml of dry chlorobenzene wasmixed with a solution of 144 g (0.5 mols) of 4-(4-amino-3,5-diisopropylbenzyl)-cyclo-hexylamine in the same manner as described in Example la). The mixture was brought to reflux temperature with phosgene and was boiled for 2 hours. De-phosgenation was carried out and the product was purified by dis-tillation under reduced pressure. The yield of 4-(4-isocyanato-3,5-diisopropylbenzyl)-cyclohexylisocyanate amounted to 154 g. The product had the following properties:
NCO content: 24.6%;
Boiling point: 170-190C/0.1 mbar;
Hydrolyzable chlorine: 0.05%;
Viscosity: 500 mPa.s/25C.
Example 5 5a) 250 g (l.L8 mols) of 4t4'-diamino-3-methyldiphenylmethane were hydrogenated in the pre-sence of 25 g of a ruthenium catalyst (5 wt. ~
ruthenium on A12O3) and 25 g of ammonia by the same procedure as was used in Example la). The crude product was taken up in methanol, the catalyst was filtered and Mo-2526 5~
washed, and the combined solutions were subjected to fractional distillation under reduced pressur~. In the main fraction, 210 g of diamine having a boiling point of 125-135C/0.1 mbar were obtained. This diamine was 85.0% 4-~-amino-3-methylbenzyl)-cyclohexylamine, 13~ 4,4'~diaminodicyclohexylmethane and 2~ 4,4'-diaminodiphenylmethane.
Sb) A s~lution of 400 g of phosgene in 1300 ml of dry chlorobenzene was introduced into an autoclave at -5 to 8C. 210 g of ~he diamine of Example 5a) dissolved in 1300 ml of chlorobenzene were added drop-wise with cooling and stirring. The resulting suspen-sion was heated to 130~C with the introduction of 100 g/h of phosgene. The solids melted at from 50 to 60C.
An emulsion formed but it changed into a clear solution at 75C. Phosgenation was carried out for 1.5 hours at 130C, followed by de-phosgenation. The resulting 4-(4-isocyana-to-3-methylbenzyl)-cyclohexylisocyanate was purified by distillation. 188 g (85~ of the theor-etical yield) of diisocyanate which boiled at from 130to 133C/0.05 mbar were obtained. According to gas chromatographLc analysis, the diisocyanate had a purity o~ 98%, an NCO content of 30.8~. The viscosity of the product was 50 mPa.s/25C.
Example 6 6a~ 226 g (1 mol) of 4,2'-diamino-3,5-dimethyldiphenylmethane and 22.6 g of ruthenium-aluminum oxide carrier catalyst (5% of Ru) were introduced into a 0.7 liter stirrer-equipped autoclave. After repeatedly flushing with nitrogen and hydroyen, 22.6 g of ammonia were metered in. The mixture was heated to 140C and hydrogenated with stirring under 200 bars hydrogen until 3 mols of hydrogen had been absorbed (reaction time of four hours). The reaction was stopped by dis-connecting the stirrer, the mixture was left to coolto room temperature, the pressure was removed~ The product was taken up in methanol. The catalyst was then Mo-2526 L68~;~
filtered, washed with methanol ar.d the combined solutions were subjected to ~'lash distillation. Z28.6 g of diamine distilled at a temperature of from 114 to 152C/0.015 mbar. The diamine was 93.0% 2-(4-amino-3,5-dimethyl-benzyl)-cyclohexylamine, 6.3% 4 r 2'-diamino-3,5-dimethyl-dicyclohexylmethane and 0.6~ of unreacted starting materials.
6b) 200 g of phosgene were dissolved in 430 ml of anhydrous chlorobenzene at from 0 to 8C. A solution of 116 g of the diamine mixture of Example 6a) in 500 ml of anhydrous chlorobenzene was added dropwise to the phosgene solution with stirring and cooling such that the temperature of the reaction mixture did not exceed 10C. The mixture was then heated to 120C with the introduction of 120 g/h of phosgene, during which the resulting suspension dissolved. The mixture was then stirred for an additional 3 hours under the same condi-tions. After de-phosgenating for two hours, the product was purified by flash distillation and fine distillation at 126C/0.06 mbar~
127.4 g (96% of the theoretical yield) of 2-(4-isocyanato-3,5-dimethylbenzyl)-cyclohexylisocyanate which'had an NCO content of 29.6%, a content of hydrolyz-abl'e chlorine of 0.01% and a viscosity of 110 mPa.s/
25C were obtained.
Example 7 7a) A 0.7 liter stirrer-equipped autoclave was charged with 212 g (1 mol) of 4,2'-diamino-3-methyldiphenylmethane and 21.2 g of ruthenium-aluminum oxide carrier catalyst (Ru content 5%). After flushing with nitrogen and hydrogen, 21.2 g of ammonia were metered in. Hydrogenation was then carried out with stirring at a temperature of 140C and under a ~ressure of 200 bars until 3 mols of hydrogen had been absorbed.
Mo-2S26 6~35~
The autoclave was then left to cool to room temp~rature, the pressure was removed and the crude product was taken up in methanol. The catalyst was separated by filtration, washed with methanol and the product was purified by distillation. 153.4 g of 2-~4-amino-3-methylbenzyl)-cyclohexylamine distilled at a temperature of from 145 to 149C/0.018 mbar. According to gas chromatographic analysis, the product had a purity of 98.4%.
7b) lO9 g of 2-(4-amino-3-methylbenzyl)-cyclo-hexylamine from Example 7a), dissolved in 500 ml of anhydrous chlorobenzene were added dropwise with stir-ring and cooling into a solution of 200 g of phosgene in 430 ml of anhydrous chlorobenzene. Thereafter, the resulting suspension was heated to reflux temperature with the introduction of phosgene and was boiled for an additional 4 hours. De-phosgenation was carried out for 2 hours, the solvent was distilled off under reduced pressure and the crude product was purified by distil-ling it twiceO 122.6 g (92% of the theoretical yield~of 2-(4~isocyanato-3-methylbenzyl)-cyclohexylisocyanate were obtained. The product diisocyanate had the following properties:
Boiling point: 135C/0.05 mbar;
NCO value: 31.0%;
Content of hydrolyzable chlorine: 0.03~;
Viscosity: 50 mPa.s/25C.
Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations cah be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
Mo-2526
SUMMARY OF THE INVENTION
It is an object of the present inVention to provide new diisocyanates having aromatically and cyclo-aliphatically bound isocyanate groups.
It is also an object of the present invention ~ to provide liquid diisocyanates having aromatically and i~ cycloaliphatically bound isocyanate groups which have a ~ 10 low viscosity at room temperature.
,~ It is another object of the present invention to provide diisocyanates having aromatically and cyclo-',~ aliphatically bound isocyanate groups which are soluble ~ and compatible with hydroxyl group-containing compounds.
,~ 15 It is a further object of the present invention to provide diisocyanates having aromatically and cyclo-aliphatically bound isocyanate groups with a low content of unhydrogenated or perhydrogenated diisocyanates.
It is yet another object of the present inven-tion to provide a process for the production of diiso-cyanates having aromatically and cycloaliphatically bound isocyanate groups in high yield.
These and other objectswhich will be apparent to those skilled in the art are accomplished by phos-25 genating diamines or isomer mixtures of diamines cor-responding to the formula /R
(H2N)m ~ 2 ~ NH2 (NH2)n R
in which Rl, R , m and n are as defined below at a temperature of from -20 to 250C.
: Mo-2526 s~
; `! - 3--~ DETAILED DESCRIPTION OF THE INVENTION
"
l, The present invention provides diisocyanates '"J, which correspond to the formula: 1 '~3 ~F~
}~ (OCN)m ~ 2 ~ NCO
~ 2 ';A~ (NCO)n R
-. 5 in which l and R2 which may be the same or diferent each represent hydrogen or (optionally branched) , alkyl groups having from 1 to 12 carbon atoms, ~, provided that at least one of the radicals i 10 Rl and R2 represents an alkyl radical, and .l m and n each represent 0 or 1, provided that the total of m + n - 1 and when m or n = 0, the remaining free valency is saturated by hydrogen~
t~ ~ 15 These diisocyanates may be in the form of isomer mix-~ ~ tures and may be present in admixture with minor amounts }~` : of the corresponding perhydrogenated diisocyanates and/or ~: corresponding unhydrogenated aromatic diisocyanates.
This invention also provides a process for ~; 20 the production of such diisocyanates or diisocyanate mixtures, in which the aminobenzyl-cyclohexylamines ,~ on which the product diisocyanates are based and which t~ are optionally present as a position and/or stereo isomer mixture and optionally in admixture with minor quantities of the corresponding perhydrogenated diamines and/or the corresponding unhydrogenated aromatic diamines are phosgenated in a known manner at from -20 to +250C.
This invention further provides a process for the production of polyurethane plastics by the isocya~
nate-polyaddition process from the diisocyanates of the present invention.
''` .
~: Mo-2526 ~, ',`
.
i858 Startiny materials for the production of the diisocyanates of the present invention are diamines or ~ mixtures of position and/or stereoisomers of diamines I corresponding to the formula: R1 (H2N)m ~ CH2 ~ 2NH2 ~NH2)n R
in which Rll R2, m and n are as defined above. Preferred diamines are those in which Rl and/or R2 represents alkyl groups having from 1 to 4 ~arbon atoms and especially methyl groups.
The diamines or diamine mixtures which are used in the present invention are often mixtures in which minor quantities of the corresponding perhydrogenated diamines and/or with minor quantities of the correspond-ing unhydrogenated aromatic diamines are present. Theexpression "minor quantities" as used herein means that the proportion of perhydrogenated or unhydrogenated diamines is in each case a maximum of 15, preferably a maximum of S wt. %, based on total diamine mixture.
According to NMR spectroscopic findings, the main compo-nent or the main components of the diamines or diamine mixtures of the present invention (i.e., the amino-benzyl-cyclohexylamines) are almost exclusively asym-metric diamines of the specified structure in which the alkyl substituents are bonded to the aromatic ring.
The composition of the diisocyana~es or of the diiso-cyanate mixtures of this invention ~orresponds to the composition of the diamines or diamine mixtures used as starting material in the process of the present inven-tion.
The diamines to be used in the present inven-tion are preferably produced by partial nuclear hydro-genation of the alkyl-substituted diaminodiphenyl Mo-2526 ~2J1 6858 methanes on which they are based. These asymmetrically substituted diaminodiphenyl methanes may be obtained, for example by condensation of _- and/or ~~nikrobenzyl halides (particularly chlorides) with substituted anilines corresponding to the formula in which Rl and R2 are as defined above, and reduction of the nitro group to produce the primary amine and by subsequent transposition. Such a procedure is disclosed in Belgian Patent 864,533 and British Patent 1,567,114.
Depending upon whether pure _-nitrobenzyl halide or pure p-nitrobenzyl halide or mixtures of these isomers are used during the condensation reaction, the ratio of the 4,4'-diamino-3(,5)-(di)-alkyldiphenylmethanes to the 4,2'-diamino~3(,5)-(di)-alkyldiphenylmethanes corresponds substantially to the isomer ratio of _-nitrobenzyl halide to o-nitrobenzyl halide used in the condensation reaction. Only when monosubstituted anilines (R2 = H) are used are minor quantities (up to 5 wt. %, based on the total mixture) of 2,4'-diamino-3-alkyldiphenyl-methanes and/or of the corresponding 2,2'-isomers pro-duced.
The nuclear hydrogenation of the aromatic diamines may be carried out by methods known to those in the art (see U.S. Patent 2,511,028). In one such method, aromatic diamines are hydrogenated catalytical-ly with the addition of 3 mols of hydrogen per mol of diamine. The hydrogenation reaction is preferably interrupted after the consumption of 3 mols of hydrogen per mol of starting compound.
Mo-2526 -' ~2~6~S~
Hydrogenation is carri0d out at from 20 ~o 300~, preferably from 70 to 300C and most preerably from 120 to 250C under a pressure o~ from 20 to 300 ~ars, pre-ferably from 70 to 300 bars and mosk preferably rom 120 to 250 bars.
The hydrogenation reaction is generally carried out in the presence of from 0.1 to lO wt.%, preferably from 0.1 to l wt. % of a hydrogenation catalyst, based on catalytically active metal and on diamino compounds.
Suitable catalysts include, for example, elements of the VIII Secondary Group of the Periodic System of Elements which are optionally present on inert carriers (such as active carbon, silica gel and in particular aluminum oxide) or catalytically active inorganic compounds of these elements. Specific examples of appropriate cata-lysts are ruthenium, platinum, rhodium, nickel and/or cobalt in elementary or chemically bound form. Ruthen-ium or catalytically active ruthenium compounds are preferred. Examples of suitable ruthenium compounds include ruthenium dioxide, ruthenium tetroxide; barium perruthenite; sodium, potassium, silver, calcium or magnesium ruthenate; sodium perruthenate; ruthenium pentafluoride; ruthenium tetrafluoride hydrate and ruthenium trichloride. If a material is used as both carrier and catalyst, the metal content of the carrier catalyst is generally from l to lO wt. ~, preferably from l to 5 wt. %. The type and quantity of catalyst to be used is not essential to the present invention.
It is often appropriate to carry out the hydrogenation reaction in the presence of ammonia because a~monia suppresses undesired deamination reac-tions and the formation o~ secondary amines as ky-products. If ammonia i5 used, it may be used in quan-tities of from 0.1 to 30 wt. %, preferably from 5 to lO
wt. ~ (based on the starting materials to be hydrogen-ated).
Mo-25~6 ~6~S~
The hydrogenation reaction may be carried out without a solvent or in the presence of an inert sol-vent. Low-melting or liqu~d diamines are generally hydrogenated without using a solvent. High-melting diamines are generally hydrogenated in dissolved form.
Organic compounds which are inert under the reaction conditions and which have a low boiling point are suit-able as solvents. Bxamples of suitable solvents are alcohols such as methanol, ethanol, n-propanol and i_ propanol; ethers such as dioxane, tetrahydrofuran and diethyl ether; and hydrocarbons such as cyclohexane.
Hydrogenation may be carried out continuously in a reaction $ube or in a pressure boiler cascade. It is preferable, however, that hydrogenation be carried out discontinuously in a stirrer-equipped autoclave by charging the autoclave with catalyst, the substance to be hydrogenated and optionally with a solvent and repeatedly flushing with inert gas and optionally meter-ing in ammonia. Hydrogenation is then injected undPr pressure, the mixture is brought to reaction temperature and hydrogenation is carried out until the theoretically necessary quantity of hydrogen has been absorbed.
After the reaction mixture has been cooled and the catalyst has been separated, the hydrogenation product may be worked up by distillation.
The hydrogenation products are obtained in high yields. Mono-alkyl-substituted diamines may be produced in amounts which are more than 70% of the theoretical yield. Dialkyl-substituted diamines may be obtained in amounts of more than 90~ of the theoretical yield. Further, the hydrogenation products may be almost completely separated by distillation from unreacted aromatic diamines or from the perhydrogenated diamines which are produced as by-products. The hydro-genation products are generally stereoisomeric mixtures,optionally also position isomer mixtures which corres-Mo-2526 685~
pond substantially to the starting materials with respect to position isomerism. It is generally not necessary to separate the products into individual position and/or stereoisomers before using them as starting materials in the process of the present inven-tion because in this process isomer purity is not necessary. In fact, isomer mixtures are often desirable because they improve the properties of the product diisocyanates.
Materials which may be produced by the above-described hydrogenation process which are preferred starting materials in the process of the present inven-tion include: 4-(4-amino-3,5-dimethylbenzyl)-cyclo-hexylamine, 4-(4-amino-3,5-diethylbenzyl)-cyclohexyl-amine, 4-(4-amino-3,5-diisopropylbenzyl)-cyclohexyl-amine, 4-(4-amino-3-ethyl-5-methylbenzyl)-cyclohexyl-amine and isomer mixtures containing these diamines as essential components; 2-(4-amino-3,5-dimethylbenzyl)-cyclohexylamine, 2-(4-amino-3/5-diethylbenzyl)-cyclo-hexylamine, 2-(4-amino-3,5-diisopropylbenzyl)-cyclo-hexylamine, 2-(4-amino-3-ethyl-5-methylbenzyl)-cyclo-hexylamine and isomer mixtures containing these diamines as essential components; 4-(4-amino-3-methylbenzyl)-cyclohexylamine, 4-t4-amino-3-ethylbenzyl)-cyclohexyl-amine, 4-(4-amino-3-isopropylbenzene)-cyclohexylamine and mixtures thereof with other position isomers (for example the corresponding 2-(4-amino-3-alkylbenzyl)-cyclohexylamines and/or 4-(2-amino-3-alkylbenzyl)cyclo-hexylamines); 2-(4-amino-3-methylbenzyl)-cyclvhexyl-amine, 2-(4-amino-3-ethylbenzyl)-cyclohexylamine, 2-(4-amino-3-isopropylbenzyl)-cyclohexylamine and mixtures thereof with the corresponding 4-(4-amino-3-alkylbenzyl)- or 4-(2-amino-3-al~ylbenzyl)-cyclohexyl-amines.
When carrying out the process of the present invention for the production of the new diisocyanates, Mo-2526 ~6~S~
phosgenation of ~he abo~e-mentioned diamines or o the salts thereof may be carried out in accordance with known methods in the presence oF an inert organic sol-vent (see Houben-Weyl, Methoden der OrganiRchen Chemie, Georg Thieme Verlag, Stuttgart (1952), Volume 8, 4th edition, pages 120 et se~).
The hydrochlorides or ammonium carbamates which may be produced by saturation of the diamine solutions with gaseous hydrogen chloride or carbon dioxide are examples of preferred salts which may be phosgenated to produce the diisocyanates of the present invention.
In principle, other salts which are produced, for example by neutralization of the diamines with proton-releasing acids may also be phosgenated.
The selectivity of the phosgenation reaction is dependent upon the amine concentration and the phos-gene excess. The phosgene is preferably used in a high molar excess which generally amounts to from 100 to 2000%, preferably from 100 to 1000%. The diamine to be phosgenated is used in a considerably dilute form. The amine concentration (based on the total quantity of amine and solvent) generally amounts to 0.1 to 15 wt. %, preferably from 5 to 10 wt. %.
Any inert organic liquids or mixtures thereof which have a boiling point of from 60 to 250C may be used as solvent in the phosgenation process. Examples of appropriate solvents include halogenated hydrocarbons, aromatic compounds, hydroaromatic compounds and chlorine compounds thereof. The following are mentioned as specific examples of suitable solvents: xylene, mesi-tylene, chlorobenzene, dichlorobenzenei trichlorobenzene, chlvronaphthalene and dichloroethane.
The reaction may be carried out either in one stage by hot phosgenation at a temperature of from 100 to 25~C, or in two stages by cold/hot phosgenation at Mo-2526 a temperature of from -20 to 250C under normal pressure, When free amines are used as the starting compound (base phosgenation), ammonium carbamic acid chloride i8 ~irst produced at a temperature of from -20 to ~60C. This ammonium carbamic acid chloride further reacts with phos-gene to produce the diisocyanate at a temperature o~
from 20 to 250C. The products are generally purified after de-phosgenation by evaporating the solvent and by subsequent distillation under reduced pressure.
The products of the process of the present invention, i.e., the new diisocyanates of this invention are produced in high yields as colorless, low viscosity liquids. These diisocyanates are valuable synthesis components in the production of polyurethane plastics by the isocyanate-polyaddition process. The position and/or stereoisomerism of the new diisocyanates corres-ponds to the isomerism of the diamines which are used as starting materials for the phosgenation process.
It is not generally necessary to separate the mixtures produced by the process of the present invention into individual position and/or stereoisomers because the products may be used directly in the production of poly-urethanes. The new diisocyanates of this invention are particularly advantageous for the production of poly-urethane lacquers, polyurethane elastomers and polyure-thane foams. Such polyurethanes may be produced by processes known to those skilled in the art by using the diisocyanates of the present invention instead of or together with the polyisocyanates which have been used by those in the art. The new diisocyanates or diisocyanate mixtures of the present invention are particularly advantageous in the production of poly-urethane plastics by the prepolymer process.
The following examples illu~.trate the present invention. All percentages relate to percent by weight, Mo-2526 ~3 6~S~
unless otherwise indicated. The analysis of the isomer distribution of the intermediate and end products was carried out by yas chromatography.
EXAMPLES
Example 1 la) 250 g (1.04 mols) of 4,4'-diamino-3-ethyl-5-methyl-diphenylmethane and 25 g of ruthenium-aluminum oxide carrier catalyst (5~ of Ru on A12O3) were intro-duced into a 0.7 liter stirrer-equipped autoclave.
After repeated flushing with nitrogen and hydrogen, 25 g of ammonia were introduced with mixing. The mixture was heated with stirring to 150-155C and hydrogenated under 200 bars until 3.12 mols of hydrogen had been absorbed. Thereafter, the mixture was allowed to cool, the autoclave pressure was relaxed and the crude product dissolved in methanol. The catalyst was filtered and washed with methanol. The organic solutions were com-bined. After evaporation of the solvent, the product was subjected to a flash-distillation and then distilled by fractionation. 220 g of diamine having a boiling point of from 125 to 130C/0.05 mbar were obtained.
According to gas chromatographic findings, this diamine was 97.2% 4-(4-amino-3-ethyl-5-methylbenzyl)-cyclo-hexylamine, 0.8% 4,4'-diamino-3-ethyl-5-methyldicyclo-hexylmethane and 2.0~ unreacted starting material andunknown diamine.
lb) 250 g of phosgene were dissolved in 700 ml of chlorobenzene at from -5 to 8C. A solution of 123 g of the diamine produced in Example la) in 700 ml of chlorobenzene was added to the phosgene solution drop-wise with stirring. A suspension was produced which heated to 20C. The mixture was heated to 130C as 100 g/h of phosgene was introduced. The solids dis-solved and the solution was boi~ed for an additional 2 Mo-2526 ~l~1tii8S~3 hours under reflux. Thereafter, the addition o phos-gene was completed. Excess phosgene was blown out with nitrogen and the crude product was purified by di~til-lation. 139 g (96% of the theoretical yield) of 4-(4-isocyanato-3-ethyl~5-methylbenzyl)-cyclohexyl isocyanate were produced. The product had the following properties:
Boiling point: 133 to 135~C/0.05 mbar;
NCO value: 28.3%;
Viscosity. 110 mPa.s~25C;
Content of hydrolyzable chlorine: 0.02~.
Example 2 2a) 250 g (1.11 mols) of 4,4'-diamino-3,5-dimethyldiphenylmethane were hydrogenated in the presence of 25 g of ruthenium-aluminum oxide carrier catalyst and 25 g of ammonia at 140C and under 200 bars by the same procedure described in Example la). This hydrogenation continued until 3.3 mols of hydrogen had reacted off.
After purifying by flash distillation and fine distilla-tion at from 150 to 155C/0.1 to 0.2 mbar, 200 g of pro-duct were obtained. According to gas chromatographicanalysis, the product was 97.4% 4-(4-amino-3,5-dimethyl-benzyl~-cyclohexylamine, 2.1% 4,4'-diamino-3,5-dimethyl-dicyclohexylmethane and 0.5% unreacted starting material.
2b) 116 g of the diamine mixture produced in Example 2a~ dissolved in 700 ml of chlorobenzene were added dropwise with intensive stirring into a solution of 200 g of phosgene in 700 ml of anhydrous chloro-benzene at from 0 to 8C. The resulting suspension was heated to 120C with the introduction of 100 g/h of phosgene. During this procedure, the solids slowly dissolved and a clear solution resulted at 65C.
After phosgenating for two hours at 120C, the solution was de-phosgenated and the crude product was purified by distillation. 121 g (87.5% of the theoretical yield) of 4-(4-isocyanato-3,5-dimethylbenzyl)-cyclo-Mo-2526 ~6~
hexyl isocyanate having a boiling point of from 138 to 141C/0.1 mbar, an NCO content of 29.5% and a viscosity oE 140 mPa.s/25C were obtained.
~xample 3 3a) A 0.7 liter stirrer-equipped autcclave was charged with 250 g (0.98 mols) of 4,4'-diamino 3,5-diethyldiphenylmethane and 25 g of ruthenium-aluminum oxide carrier catalyst (5% of Ru on A12O3). The auto-clave was then flushed with nitrogen and 25 g of ammonia were metered in. Thereafter, the mixture was hydrogenated at 140C and under 200 bars until 3 mols of hydrogen had been consumed. The autoclave was allowed to cool, the pressure therein was relaxed, the product was taken up in methanol and the catalyst was filtered. The solvent was then drawn off and the hydrogenated diamine was purified by flash and fine distillation at from 136 to 140C/0.1 mbar. 170 g of diamine having a content of 95.8% 4-~4-amino-3,5-di-ethylbenzyl)-cyclohexylamine, 3,3% of perhydrogenated starting diamine and 0.9~ of unreacted starting material were obtained (according to gas chromato-graphic analysis).
3b) 200 g of phosgene were dissolved in 700 ml of anhydrous chlorobenzene. A solution of 130 g of diamine from ~xample 3a) in 700 ml of dry chlorobenzene was added dropwise to the phosgene solution with stir-ring and cooling. A dispersion which was difficult to stir and which changed into a clear solution during heating with the introduction of phosgene at 80C
formed. The solution was boiled for 2 hours under reflux, the addition of phosgene was completed, the solution was de-phosgenated and the crude product was distilled at 135C/O.9S mbar. 134 g (90% of the theoretical yield) of 4-(4 isocyanato-3,5-diethyl-benzyl)-cyclohexylisocyanate, were obtained having an NCO content of 27.0% and a viscosity of 90 mPa.s/2SC.
Mo-2526 ~l~216~
Example 4 4a) 250 g (0.89 mols) of 4,4'-diamino-3,5-diisopropyl-diphenylmethane were hydrogena~ed in the presence of 25 g of xuthenium-aluminum oxide carrier catalyst (5% of Ru on A12O3) and 25 g of ammonia at 140C/200 bars by the same procedure as that used in Example la), until 2.7 mols of hydrogen had been absorbed. After flash distillation, the product was subjected to fractional distillation. During this procedure, 214 g of 4-(4-amino-3,5-diisopropylbenzyl)-cyclohexylamine were produced in the main fraction.
According to gas chromatographic analysis, 0.5% of perhydrogenated diamine and 0.5~ of starting diamine were present in the product diamine.
4b) A solution of 200 g of phosgene in 700 ml of dry chlorobenzene wasmixed with a solution of 144 g (0.5 mols) of 4-(4-amino-3,5-diisopropylbenzyl)-cyclo-hexylamine in the same manner as described in Example la). The mixture was brought to reflux temperature with phosgene and was boiled for 2 hours. De-phosgenation was carried out and the product was purified by dis-tillation under reduced pressure. The yield of 4-(4-isocyanato-3,5-diisopropylbenzyl)-cyclohexylisocyanate amounted to 154 g. The product had the following properties:
NCO content: 24.6%;
Boiling point: 170-190C/0.1 mbar;
Hydrolyzable chlorine: 0.05%;
Viscosity: 500 mPa.s/25C.
Example 5 5a) 250 g (l.L8 mols) of 4t4'-diamino-3-methyldiphenylmethane were hydrogenated in the pre-sence of 25 g of a ruthenium catalyst (5 wt. ~
ruthenium on A12O3) and 25 g of ammonia by the same procedure as was used in Example la). The crude product was taken up in methanol, the catalyst was filtered and Mo-2526 5~
washed, and the combined solutions were subjected to fractional distillation under reduced pressur~. In the main fraction, 210 g of diamine having a boiling point of 125-135C/0.1 mbar were obtained. This diamine was 85.0% 4-~-amino-3-methylbenzyl)-cyclohexylamine, 13~ 4,4'~diaminodicyclohexylmethane and 2~ 4,4'-diaminodiphenylmethane.
Sb) A s~lution of 400 g of phosgene in 1300 ml of dry chlorobenzene was introduced into an autoclave at -5 to 8C. 210 g of ~he diamine of Example 5a) dissolved in 1300 ml of chlorobenzene were added drop-wise with cooling and stirring. The resulting suspen-sion was heated to 130~C with the introduction of 100 g/h of phosgene. The solids melted at from 50 to 60C.
An emulsion formed but it changed into a clear solution at 75C. Phosgenation was carried out for 1.5 hours at 130C, followed by de-phosgenation. The resulting 4-(4-isocyana-to-3-methylbenzyl)-cyclohexylisocyanate was purified by distillation. 188 g (85~ of the theor-etical yield) of diisocyanate which boiled at from 130to 133C/0.05 mbar were obtained. According to gas chromatographLc analysis, the diisocyanate had a purity o~ 98%, an NCO content of 30.8~. The viscosity of the product was 50 mPa.s/25C.
Example 6 6a~ 226 g (1 mol) of 4,2'-diamino-3,5-dimethyldiphenylmethane and 22.6 g of ruthenium-aluminum oxide carrier catalyst (5% of Ru) were introduced into a 0.7 liter stirrer-equipped autoclave. After repeatedly flushing with nitrogen and hydroyen, 22.6 g of ammonia were metered in. The mixture was heated to 140C and hydrogenated with stirring under 200 bars hydrogen until 3 mols of hydrogen had been absorbed (reaction time of four hours). The reaction was stopped by dis-connecting the stirrer, the mixture was left to coolto room temperature, the pressure was removed~ The product was taken up in methanol. The catalyst was then Mo-2526 L68~;~
filtered, washed with methanol ar.d the combined solutions were subjected to ~'lash distillation. Z28.6 g of diamine distilled at a temperature of from 114 to 152C/0.015 mbar. The diamine was 93.0% 2-(4-amino-3,5-dimethyl-benzyl)-cyclohexylamine, 6.3% 4 r 2'-diamino-3,5-dimethyl-dicyclohexylmethane and 0.6~ of unreacted starting materials.
6b) 200 g of phosgene were dissolved in 430 ml of anhydrous chlorobenzene at from 0 to 8C. A solution of 116 g of the diamine mixture of Example 6a) in 500 ml of anhydrous chlorobenzene was added dropwise to the phosgene solution with stirring and cooling such that the temperature of the reaction mixture did not exceed 10C. The mixture was then heated to 120C with the introduction of 120 g/h of phosgene, during which the resulting suspension dissolved. The mixture was then stirred for an additional 3 hours under the same condi-tions. After de-phosgenating for two hours, the product was purified by flash distillation and fine distillation at 126C/0.06 mbar~
127.4 g (96% of the theoretical yield) of 2-(4-isocyanato-3,5-dimethylbenzyl)-cyclohexylisocyanate which'had an NCO content of 29.6%, a content of hydrolyz-abl'e chlorine of 0.01% and a viscosity of 110 mPa.s/
25C were obtained.
Example 7 7a) A 0.7 liter stirrer-equipped autoclave was charged with 212 g (1 mol) of 4,2'-diamino-3-methyldiphenylmethane and 21.2 g of ruthenium-aluminum oxide carrier catalyst (Ru content 5%). After flushing with nitrogen and hydrogen, 21.2 g of ammonia were metered in. Hydrogenation was then carried out with stirring at a temperature of 140C and under a ~ressure of 200 bars until 3 mols of hydrogen had been absorbed.
Mo-2S26 6~35~
The autoclave was then left to cool to room temp~rature, the pressure was removed and the crude product was taken up in methanol. The catalyst was separated by filtration, washed with methanol and the product was purified by distillation. 153.4 g of 2-~4-amino-3-methylbenzyl)-cyclohexylamine distilled at a temperature of from 145 to 149C/0.018 mbar. According to gas chromatographic analysis, the product had a purity of 98.4%.
7b) lO9 g of 2-(4-amino-3-methylbenzyl)-cyclo-hexylamine from Example 7a), dissolved in 500 ml of anhydrous chlorobenzene were added dropwise with stir-ring and cooling into a solution of 200 g of phosgene in 430 ml of anhydrous chlorobenzene. Thereafter, the resulting suspension was heated to reflux temperature with the introduction of phosgene and was boiled for an additional 4 hours. De-phosgenation was carried out for 2 hours, the solvent was distilled off under reduced pressure and the crude product was purified by distil-ling it twiceO 122.6 g (92% of the theoretical yield~of 2-(4~isocyanato-3-methylbenzyl)-cyclohexylisocyanate were obtained. The product diisocyanate had the following properties:
Boiling point: 135C/0.05 mbar;
NCO value: 31.0%;
Content of hydrolyzable chlorine: 0.03~;
Viscosity: 50 mPa.s/25C.
Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations cah be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
Mo-2526
Claims (19)
1. A diisocyanate corresponding to the formula in which R1 and R2 which may be the same or different each represent hydrogen or alkyl groups having from 1 to 12 carbon atoms, provided that at least one of the radicals R1 and R2 represents an alkyl radical and m and n each represent 0 or 1 provided that m + n equals 1 and when m or n equals 0 the remain-ing free valence is saturated by hydrogen.
2. The diisocyanate of Claim 1 in the form of an isomeric mixture.
3. The diisocyanate of Claim 2 in which a quantity of up to 15 wt % of the corresponding perhydro-genated diisocyanate and/or the corresponding unhydro-genated aromatic diisocyanate is present.
4. The diisocyanate of Claim 2 in which m represents 1 and R1 and R2 each represent an alkyl group having from 1 to 4 carbon atoms.
5. The diisocyanate of Claim 2 in which n represents 1 and R1 and R2 each represent an alkyl group having from 1 to 4 carbon atoms.
6. The diisocyanate of Claim 2 in which m represents 1, R1 represents an alkyl group having 1 to 4 carbon atoms and R2 represents hydrogen.
7. The diisocyanate of Claim 2 in which n represents 1, R1 represents an alkyl group having 1 to 4 carbon atoms and R represents hydrogen.
8. The diisocyanate of Claim 1 in which a quantity of up to 15 wt % of the corresponding perhydro-genated diisocyanate and/or the corresponding unhydro-genated aromatic diisocyanate is present.
9. The diisocyanate of Claim 1 in which m represents 1 and R1 and R2 each represent an alkyl group having from 1 to 4 carbon atoms.
10. The diisocyanate of Claim 1 in which n represents 1 and R1 and R2 each represent an alkyl group having from 1 to 4 carbon atoms.
11. The diisocyanate of Claim 1 in which m represents 1, R1 represents an alkyl group having 1 to 4 carbon atoms and R represents hydrogen.
12. The diisocyanate of Claim 1 in which n represents 1, R represents an alkyl group having 1 to 4 carbon atoms and R2 represents hydrogen.
13. A process for the production of the diiso-cyanate of Claim 1 comprising phosgenating an amine corresponding to the formula in which R1 and R2 which may be the same or different each represent hydrogen or alkyl groups having from 1 to 12 carbon atoms, provided that at least one of the radicals R1 and R2 represents an alkyl radical and m and n each represent 0 or 1 provided that m + n equals 1 and when m or n equals 0 the remaining free valence is saturated by hydrogen at a temperature of from -20 to 250°C.
14. The process of Claim 13 in which the amine starting material is an isomer mixture.
15. The process of Claim 14 in which the amine starting material contains a quantity of up to 15 wt %
of the corresponding perhydrogenated diamine and/or the corresponding unhydrogenated aromatic diamine.
of the corresponding perhydrogenated diamine and/or the corresponding unhydrogenated aromatic diamine.
16. The process of Claim 13 in which the amine starting material contains a quantity of up to 15 wt %
of the corresponding perhydrogenated diamine and/or the corresponding unhydrogenated aromatic diamine.
of the corresponding perhydrogenated diamine and/or the corresponding unhydrogenated aromatic diamine.
17. A process for the production of polyurethanes by the isocyanate-polyaddition process comprising reacting the diisocyanate of Claim 1 with an isocyanate-reactive material.
18. The process of Claim 17 in which the diisocyanate starting material is an isomeric mixture.
19. The process of Claim 18 in which the diisocyanate starting material contains a quantity of up to 15 wt % of the corresponding perhydrogenated diiso-cyanate and/or the corresponding unhydrogenated aromatic diisocyanate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19823245320 DE3245320A1 (en) | 1982-12-08 | 1982-12-08 | DIISOCYANATE OR DIISOCYANATE MIXTURES, A METHOD FOR THE PRODUCTION THEREOF AND THEIR USE FOR THE PRODUCTION OF POLYURETHANE PLASTICS |
| DEP3245320.5 | 1982-12-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1216858A true CA1216858A (en) | 1987-01-20 |
Family
ID=6180055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000442676A Expired CA1216858A (en) | 1982-12-08 | 1983-12-06 | Diisocyanates, diisocyanate mixtures and a process for their production |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0113043B1 (en) |
| JP (1) | JPS59112955A (en) |
| CA (1) | CA1216858A (en) |
| DE (2) | DE3245320A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3417684A1 (en) * | 1984-05-12 | 1985-11-14 | Bayer Ag, 5090 Leverkusen | NEW TRIISOCYANATES, A METHOD FOR THE PRODUCTION THEREOF AND THEIR USE FOR THE PRODUCTION OF POLYURETHANE PLASTICS |
| IL112569A (en) * | 1994-02-10 | 1999-12-22 | Wyeth John & Brother Ltd | Pharmaceutical compositions comprising cyclohexylamine derivatives certain such novel compounds and their preparation |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3663514A (en) * | 1970-04-09 | 1972-05-16 | Phillips Petroleum Co | Light-stable polyurethane coatings |
-
1982
- 1982-12-08 DE DE19823245320 patent/DE3245320A1/en not_active Withdrawn
-
1983
- 1983-11-26 EP EP83111852A patent/EP0113043B1/en not_active Expired
- 1983-11-26 DE DE8383111852T patent/DE3360797D1/en not_active Expired
- 1983-12-06 CA CA000442676A patent/CA1216858A/en not_active Expired
- 1983-12-08 JP JP58230728A patent/JPS59112955A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59112955A (en) | 1984-06-29 |
| DE3245320A1 (en) | 1984-06-14 |
| EP0113043B1 (en) | 1985-09-11 |
| DE3360797D1 (en) | 1985-10-17 |
| EP0113043A1 (en) | 1984-07-11 |
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