U.S. patent application number 10/020007 was filed with the patent office on 2002-09-19 for isomeric nonanols and decanols, their preparation, phthalic esters obtained therefrom, and their use as plasticizers.
Invention is credited to Bahrmann, Helmut, Fenske, Wilfried, Greb, Wolfgang, Heymanns, Peter, Lappe, Peter, Muller, Thomas, Szameitat, Jurgen, Wiebus, Ernst.
Application Number | 20020133047 10/020007 |
Document ID | / |
Family ID | 6476147 |
Filed Date | 2002-09-19 |
United States Patent
Application |
20020133047 |
Kind Code |
A1 |
Bahrmann, Helmut ; et
al. |
September 19, 2002 |
Isomeric nonanols and decanols, their preparation, phthalic esters
obtained therefrom, and their use as plasticizers
Abstract
Mixtures of isomeric nonanols and decanols are obtained by joint
aldol condensation of n-butanal and pentanals, and up to 1% by
weight of 3-methylbutanal, hydrogenation of the aldol condensation
product to the corresponding saturated alcohols, and separation
from the reaction mixture of the components boiling at temperatures
lower than those of the nonanols and decanols. The pentanals are
mixtures of 60 to 90% by weight of n-pentanal and 10 to 40% by
weight of 2-methylbutanal. The alcohol mixture is especially
suitable for preparing ester plasticizers.
Inventors: |
Bahrmann, Helmut;
(Hamminkeln, DE) ; Fenske, Wilfried; (Hamminkeln,
DE) ; Greb, Wolfgang; (Dinslaken, DE) ;
Heymanns, Peter; (Essen, DE) ; Lappe, Peter;
(Dinslaken, DE) ; Muller, Thomas; (Dinslaken,
DE) ; Szameitat, Jurgen; (Wesel, DE) ; Wiebus,
Ernst; (Oberhausen, DE) |
Correspondence
Address: |
Bierman, Muserlian and Lucas
600 Third Avenue
New York
NY
10016
US
|
Family ID: |
6476147 |
Appl. No.: |
10/020007 |
Filed: |
December 13, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10020007 |
Dec 13, 2001 |
|
|
|
08437221 |
May 8, 1995 |
|
|
|
Current U.S.
Class: |
568/840 |
Current CPC
Class: |
C07C 29/175 20130101;
C07C 45/50 20130101; C07C 45/74 20130101; C12C 11/02 20130101; C07C
69/80 20130101; C08K 5/12 20130101; C07C 29/175 20130101; C07C
31/125 20130101; C07C 45/74 20130101; C07C 47/21 20130101; C07C
45/50 20130101; C07C 47/02 20130101 |
Class at
Publication: |
568/840 |
International
Class: |
C07C 031/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 1992 |
DE |
P 42 43 524.2 |
Claims
What we claim is:
1. A mixture of isomeric nonanols and decanols which is the product
of a joint aldol condensation of n-butanal and pentanals in a molar
ratio of 1:2 to 1:10 wherein said pentanals comprise 60% to 90% by
weight of n-pentanal, 10% to 40% by weight of 2-methyl butanal, and
up to 1% by weight of 3-methyl butanal, to form an aldol
condensation product, hydrogenation of said condensation product to
form said isomeric nonanols and decanols, and separation therefrom
of components having boiling points below those of said nonanols
and decanols.
2. The mixture of claim 1 wherein said pentanals comprise 65% to
80% by weight of n-pentanal, 20% to 35% by weight of
2-methylbutanal, and up to 1% by weight of 3-methylbutanal.
3. A process for preparation of isomeric nonanols and decanols
wherein propylene and butenes are hydroformylated separately to
form mixtures of butanals and pentanals, joint condensation of said
mixtures in the presence of at least one basic catalyst to form a
condensation product, hydrogenation of said condensation product to
form said nonanols and decanols, and separation from said nonanols
and decanols of components having boiling points below those of
said nonanols and decanols.
4. The process of claim 3 wherein said catalyst comprises
rhodium-phosphine complexes.
5. The process of claim 4 wherein said hydroformylation is carried
out at 70.degree. to 150.degree. C. and under a pressure of 0.4 to
30 MPa.
6. The process of claim 3 wherein said condensation is at
60.degree. to 160.degree. C. in the presence of at least one
tertiary amine.
7. The process of claim 3 wherein said hydrogenation is in the
presence of at least one nickel catalyst at 100.degree. to
180.degree. C. under pressure of 1 to 10 MPa.
8. The process of claim 3 wherein said said separation is by
distillation.
9. The process of claim 8 wherein said distillation is at
100.degree. to 125.degree. C. under a pressure of 1 to 4 kPa.
10. A plasticizer which is the reaction product of the mixture of
claim 1 with phthalic acid and/or phthalic anhydride.
Description
[0001] This Application claims the benefit of the priority of
German Patent Application P 42 43 524.2, filed Dec. 22, 1992.
[0002] The invention relates to mixtures of isomeric nonanols and
decanols, a process for their preparation, the phthalic esters
obtained from these alcohols mixtures, and the use of these esters
as plasticizers.
BACKGROUND OF THE INVENTION
[0003] Esters of phthalic acid have wide application as
plasticizers, in particular for polyvinyl chloride. The alcohol
components are principally primary alcohols having from 8 to 10
carbon atoms, the most important among them presently being
2-ethylhexanol. Phthalic esters of short-chain alcohols give
plasticizers with good gelling powder; however, their higher
volatility is a disadvantage. In comparison, long-chain esters gel
more slowly but have poorer cold resistance.
[0004] The properties of the phthalic ester plasticizers are
affected, not only by the size of the alcohol molecule, but also by
the branching of the hydrocarbon chain. Thus, alcohols with little
branching give ester plasticizers of high cold flexibility. Largely
linear alcohols having from 9 to 10 carbon atoms in the molecule
are therefore becoming increasingly important as alcohol
components. A prerequisite for their use is that they are available
in large quantities and at advantageous prices.
[0005] In German Patent 28 55 421, the plasticizers used are
phthalates of C.sub.9-alcohols, which are obtained by the
oxo-reaction of C-.sub.8-olefins, hydrogenation of the reaction
product, and esterification of the C.sub.9-alcohols with phthalic
anhydride. From 3% to 20% by weight of the starting olefins is said
to have an isobutane skeleton in each molecular chain, less than 3%
by weight of the olefins should-contain quaternary carbon, and more
than 90% by weight of the total amount of olefins is said to be
present as n-octenes, monomethylheptenes, and dimethylhexenes.
Furthermore, the weight ratio of the total amount of the n-octenes
and monomethylheptenes to the dimethylhexenes is said to be more
than 0.8.
[0006] Phthalic esters based on C.sub.10-alcohols are the subject
of the European Patent Application 3 66 089. The C.sub.10-alcohols
are used in the form of a mixture which is obtained by
hydroformylation of a butene fraction, aldol condensation of the
aldehyde mixture thus obtained, and subsequent hydrogenation.
According to the process description, the hydroformylation step is
not subject to any limitations. The catalysts used may be cobalt as
well as rhodium; the addition of an organic compound of trivalent
phosphorus is not excluded.
[0007] Another route to obtaining didecylphthalate mixtures is
described in European Patent Application 4 24 767. The preparation
of the esters is carried out in a multistage process by
dimerization of butene mixtures., hydroformylation and
hydrogenation of the resulting octene mixture to give a nonanol
mixture, dehydration of the nonanol mixture to form a nonene
mixture, and hydroformylation and hydrogenation of the nonene
mixture to form the desired decanol mixture.
[0008] According to EP-B-52 999, plasticizer alcohols are prepared
from a mixture of propylene and butenes in a molar ratio of 2:1 to
1:3. The olefins are jointly converted by the oxo reaction to a
mixture of butyl and amyl aldehydes which is subjected to an aldol
condensation. The resulting condensation products are subsequently
hydrogenated to saturated alcohols.
[0009] The known alcohols or alcohol mixtures used for the
preparation of plasticizers do not meet all the economic and
technical requirements which are demanded of products produced on
an industrial scale, because the starting materials are not
available in sufficient quantity, the prices are too high, the
conversion of the starting materials into the alcohols necessitates
extremely costly processes, and/or the quality of the plasticizers
prepared from the alcohols leaves much to be desired.
SUMMARY OF THE INVENTION
[0010] It is therefore an object of the present invention to
develop suitable alcohol or alcohol mixtures for the preparation of
high-quality plasticizers. They should be obtained from
economically available raw materials in a technically simple
manner.
[0011] This object is achieved by mixtures of isomeric nonanols and
decanols which are obtained by joint aldol condensation of
n-butanal and pentanals in a molar ratio of from 1:2 to 1:10. The
pentanal mixtures comprise 60% to 90% by weight of n-pentanal, 10%
to 40% by weight of 2-methylbutanal and up to 1% by weight of
3-methylbutanal. The aldol condensation product is then
hydrogenated to form the saturated alcohols, and the components
boiling at lower temperatures than the nonanols and decanols are
removed from the reaction mixture.
[0012] It is preferable to use mixtures of isomeric nonanols and
decanols which are prepared from n-butanal and pentanals which
contain from 65% to 80% by weight of n-pentanal, 20% to 35% by
weight of 2-methylbutanal, and up to 1% by weight of
3-methylbutanal. The alcohol mixtures are obtained by aldol
condensation of a mixture containing n-butanal and pentanals in a
molar ratio of 1:2 to 1:10, subsequent hydrogenation of the aldol
condensation product, and removal of the 2-ethylhexanol formed. The
source of the aldehydes is immaterial; the criteria are chiefly
economic. To promote the formation of alcohols with little
branching, the aldehydes must have the carbonyl group on the
terminal carbon atom and, in the case of the pentanals, be at least
substantially unbranched. Therefore, the pentanals used are
mixtures containing from 60% to 90% by weight of n-pentanal, from
10 to 40% by weight of 2-methylbutanal, and up to 1% by weight of
3-methylbutanal.
[0013] Preferred starting materials are aldehydes prepared by
hydroformylation (oxo process) of propylene or butenes. The
required olefins are available in industrial quantities. Propylene
is obtained as byproduct in ethylene production by pyrolysis of
hydrocarbon mixtures in the presence of water vapor and also in
some refinery processes, particularly the catalytic cracking of
petroleum fractions.
[0014] Mixtures containing butene-1 and butene-2 are also
necessarily obtained in considerable quantities as refinery
byproducts in the production of automotive fuels and in the
production of ethylene by thermal cracking of higher hydrocarbons.
They are isolated from the C.sub.4 cracking fractions of the
pyrolysis product by extraction of the butadiene-1,3 by a selective
solvent, and subsequent removal of the isobutene preferably by
conversion into methyl t-butyl ether. Instead of extracting the
butadiene-1,3, it can also be partly hydrogenated to butenes in the
C.sub.4 cracking fraction. The pyrolysis product freed of
butadiene-1,3 is identified as raffinate I. If the isobutene has
also been removed, it is referred to as raffinate II. This
butene-1/butene-2 mixture is particularly suitable for further
processing into decanols.
[0015] Basically, all current commercial hydroformylation processes
are suitable for converting the olefins into aldehydes. Thus, the
process can be carried out in the presence of cobalt or rhodium
catalysts at pressures of 10 to 35 MPa and at temperatures of
120.degree. to 180.degree. C.; in the presence of cobalt/phosphine
catalysts at pressures of from 5 to 10 MPa; or in the presence of
rhodium catalysts which are modified by phosphine at temperatures
of 60.degree. to 150.degree. C. and pressures of 1 to 8 MPa. In the
last-described variant of the hydroformylation reaction, the
catalyst may be homogeneously dissolved in--or form a separate
phase from--the reaction mixture.
[0016] To prepare the aldehydes, propylene and the butenes may be
reacted together, but preferably separately. It has proven
particularly valuable to carry out the hydroformylation as a
heterogeneous reaction in a two-phase system, a reaction which is
described, for example, in DE-C-26 27 354. This embodiment of the
oxo process ensures that olefins having their double bonds at a
terminal carbon atom form largely n-aldehydes and that
isomerization of the olefins by migration of the double bond during
the reaction is essentially avoided.
[0017] The two-phase process is characterized by the presence of an
organic phase, which contains the starting olefins and the reaction
product, and an aqueous phase, in which the catalyst is dissolved.
Catalysts used are water-soluble rhodium complexes which contain
water-soluble phosphines as ligands. The phosphines include, in
particular, triarylphosphines, trialkylphosphines, and arylated or
alkylated diphosphines, the organic radicals of which are
substituted by sulfonic acid groups or carboxyl groups. Their
preparation is known and described, for example, in DE-PS 26 27 354
and DD-PS 259 194. The reaction of the olefins is carried out at
temperatures of 70.degree. to 150.degree. C., preferably
100.degree. to 130.degree. C., and at pressures in the range of 0.4
to 30, in particular 1 to 10, MPa; the water gas used contains
carbon monoxide and hydrogen in a volume ratio of 1:10 to 10:1. The
rhodium concentration is 20 to 1000 ppm by weight, preferably 50 to
500 ppm by weight, based on the aqueous catalyst solution, with
from 4 to 100 mol of water-soluble phosphine being used per mole of
rhodium. The volume ratio of aqueous to organic phase is from 0.1
to 10:1.
[0018] The conversion of the butenes is appreciably increased if a
phase-transfer reagent (solubilizer) is added to the aqueous
catalyst solution. Materials which have proven particularly
valuable are cationic solubilizers of the formula
[A--N(R.sup.1R.sup.2R.sup.3)].sup.+E, wherein A is a straight or
branched chain alkyl radical having 6 to 25 carbon atoms; R.sup.1,
R.sup.2, R.sup.3 are individually straight or branched chain alkyl
radicals having from 1 to 4 carbon atoms; and E is for example
sulfate, tetrafluoroborate, acetate, methosulfate,
benzenesulfonate, alkylbenzenesulfonate, toluenesulfonate, lactate,
or citrate.
[0019] In the described process, as much as 99% of the propylene is
converted, the butanal mixture obtained comprising over 95% by
weight of the n-compound. When butene-1/butene-2 mixtures are used,
the reaction with butene-1 is preferred. Depending on the reaction
parameters selected, more than 95% of the butene-1 or butene-2 is
converted. From 60% to 90% by weight of n-pentanal is formed, the
remainder comprising 2-methylbutanol with or without
3-methylbutanal.
[0020] After completion of the separate or joint hydroformylation,
the aldehydes are separated from the catalyst, from the unreacted
reaction components, and from the other reaction products. In the
case of the heterogeneous reaction, this is by simple phase
seperation. For reaction in the homogeneous phase, a usual
separation process such as distillation suffices.
[0021] In the subsequent aldol condensation, mixtures are used
which contain, per mole of n-butanal, 2 to 10 mol, in particular 7
to 10 mol, of pentanals. The reaction of the aldehyde mixture is
carried out in the conventional way using basic catalysts.
Pretreatment of the aldehydes, for example a special purification,
is not necessary. It is, however, advisable in the case of the
butanals to remove i-butanal from the C.sub.4-aldehyde mixture by
distillation, if the proportion thereof in the mixture exceeds
approximately 2% by weight. Suitable catalysts are alkali metal
carbonates or alkali metal hydroxides, in particular compounds of
sodium or potassium and amines, preferably tertiary amines, such as
triethylamine, tri-n-propylamine and tri-n-butylamine. The reaction
is carried out at temperatures of 60.degree. to 160.degree. C., in
particular 80.degree. to 130.degree. C., and at atmospheric
pressure or at a superatmospheric pressure of up to 1 MPa. The
reaction time is from a few minutes to several hours and is, in
particular, dependent on the catalyst type and reaction
temperature. Because of their higher reactivity, the straight-chain
aldehydes react preferentially. Self-condensation of n-butanal or
n-pentanal forms C.sub.8 or C.sub.10-enals and the mixed
condensation of n-butanal and n-pentanal gives C.sub.9-enals. The
reactions between n-butanal or n-pentanal and branched-chain
pentanals proceed at appreciably lower rates; the reaction between
branched-chain pentanals is largely insignificant.
[0022] The mixture of unsaturated aldehydes obtained by
condensation is subsequently hydrogenated to a mixture containing
nonyl and decyl alcohols together with 2-ethylhexanol and any
butanols and pentanols arising from C.sub.4- and C.sub.5-aldehydes
which may not have been converted by the aldol condensation. The
addition of hydrogen is carried out in a known manner in the
presence of catalysts. Suitable catalysts are, for example,
hydrogenation catalysts based on nickel, chromium or copper. The
hydrogenation temperature is usually between 100.degree. and
180.degree. C. and the pressure is 1 to 10 MPa. According to the
invention, the alcohol mixture obtained is subjected to
distillation at 100.degree. to 125.degree. C. and a pressure of 1
to 4 kPa (from 10 to 40 mbar) to remove 2-ethylhexanol, other
alcohols, and impurities which boil at lower temperatures than the
nonanols and decanols.
[0023] The remaining mixture of nonanols and decanols is especially
suitable as the alcohol component in phthalic esters which are to
be used as plasticizers. The preparation of phthalic esters is
known [cf. Ullmann, Encyclopdie der Technischen Chemie (1979), Vol.
18, page 536 ff]. Phthalic anhydride is advantageously reacted with
the nonanol/decanol mixture in a molar ratio of 1;2 to 1:3 in a
single stage. The reaction rate can be increased by catalysts
and/or by increasing the reaction temperature. To shift the
equilibrium in the direction of ester formation, it is necessary to
remove the water of reaction from the reaction mixture.
[0024] The phthalates obtained from the nonanol/decanol mixture of
the invention are remarkable for their low volatility and good
gelling ability.
EXAMPLE 1
[0025] 980.0 g of 2.5% NaOH (0.61 mol) is heated to 60.degree. C.
under nitrogen, and a mixture of 272.8 g (3.17 mol) of
n-valeraldehyde, 181.8 g (2.11 mol) of 2-methylbutanal, and 45.5 g
(0.63 mol) of n-butyraldehyde is added over a period of 20 minutes.
The mixture is then heated to 88.degree. to 90.degree. C. under
reflux for one hour. After cooling to 30.degree. C. the organic and
aqueous phases separate.
[0026] The aldol condensation product is hydrogenated in the
presence of a nickel catalyst at a pressure of 10 MPa and
140.degree. C. After filtering out the catalyst, a crude alcohol
mixture is obtained which has the following composition (% by
weight) determined by gas chromatography:
1 First fraction 0.2 2-methylbutanol 30.2 n-pentanol 0.3
2-ethylhexanol 1.6 2-ethyl-4-methylhexanol 2.1 2-propylhexanol 6.4
2-ethylheptanol 6.2 2-propyl-4-methylhexanol 14.7 2-propylheptanol
35.4 Final fraction 2.9
[0027] The distillative removal of the pentanols and
2-ethyl-hexanol gives an alcohol mixture with the following
composition (% by weight):
2 2-ethyl-4-methylhexanol 3.2 2-propylhexanol 9.9 2-ethylheptanol
9.6 2-propyl-4-methylhexanol 22.6 2-propylheptanol 54.7
[0028] The esterification with phthalic anhydride is carried out in
the presence of sulfuric acid as the catalyst and cyclohexane for
the azeotropic removal of the water of reaction. Neutralization,
alcohol removal, and drying result in a mixture of phthalic esters
of isomeric nonanols and decanols which has a density of 0.967 g/ml
at 20.degree. C. and a viscosity of 138 mpa.s.
EXAMPLE 2
[0029] 980.0 g of 2.5% NaOH (0.61 mol) is heated to 60.degree. C.
under nitrogen and a mixture of 214.3 g (2.49 mnol) of
n-valeraldehyde, 143.0 g (1.66 mol) of 2-methylbutanal, and 142.8 g
(1.98 mol) of n-butyraldehyde, is added dropwise over a period of
20 minutes. The mixture is heated to 89.degree. to 92.degree. C.
under reflux for one hour. After cooling to 30.degree. C., the
organic and aqueous phases separate.
[0030] Hydrogenation as in Example 1 of the condensation product
gives a crude alcohol mixture with the following composition (% by
weight) determined by gas chromatography:
3 First fraction 0.2 2-methylbutanol 20.9 n-pentanol 0.2
2-ethylhexanol 10.9 2-ethyl-4-methylhexanol 5.2 2-propylhexanol
13.9 2-ethylheptanol 13.5 2-propyl-4-methylhexanol 10.0
2-propylheptanol 22.3 Final fraction 2.9
[0031] The distillative removal of the pentanols and 2-ethylhexanol
gives an alcohol mixture with the following composition (t by
weight):
4 2-ethyl-4-methylhexanol 8.0 2-propylhexanol 21.4 2-ethylheptanol
20.8 2-propyl-4-methylhexanol 15.4 2-propylheptanol 34.4
[0032] Esterification with phthalic anhydride as in Example 1
results in an ester mixture which has a viscosity of 118 mPa.s and
a density of 0.969 g/ml.
EXAMPLE 3
[0033] A mixture of 280 g (3.25 mol) of n-valeraldehyde, 120.0 g
(1.39 mol) of 2-methylbutanal, and 120.0 g (1.66 mol) of
n-butyraldehyde is converted to aldols in the presence of 1016 g of
2.5% NaOH (0.63 mol) as in Example 1.
[0034] Hydrogenation as in Example 1 of the condensation product
gives a crude alcohol mixture with the following composition (% by
weight):
5 First fraction 0.7 2-methylbutanol 17.9 n-pentanol 0.3
2-ethylhexanol 7.0 2-ethyl-4-methylhexanol 3.6 2-propylhexanol 13.8
2-ethylheptanol 13.5 2-propyl-4-methylhexanol 9.5 2-propylheptanol
31.7 Final fraction 2.0
[0035] The distillation workup gives an alcohol mixture with the
following composition (% by weight):
6 2-ethyl-4-methylhexanol 5.1 2-propylhexanol 19.2 2-ethylheptanol
18.7 2-propyl-4-methylhexanol 13.1 2-propylheptanol 43.9
[0036] Esterification with phthalic anhydride as in Example 1
results in an ester mixture which has a viscosity of 123 mpa.s and
a density of 0.969 g/ml.
EXAMPLES 4 TO 7
[0037] The Examples 4 to 7 are carried out in the same manner as
Example 1; the data relating to the composition of the starting
mixture, the crude alcohol mixture, and the alcohol mixture
suitable for plasticizer production are shown in the following
Table.
7 Ex. Ex. Ex. Ex. 4 5 6 7 Starting mixture n-valeraldehyde (g)
156.7 208.9 139.3 234.8 (mol) 1.82 2.43 1.62 2.73 2-methylbutanal
(g) 17.4 52.0 34.8 26.1 (mol) 0.20 0.60 0.40 0.30 n-butyraldehyde
(g) 74.3 22.3 74.3 22.3 (mol) 1.03 0.31 1.03 0.31 2.5% strength
NaOH (g) 480.5 528.0 480.0 528.5 (mol) 0.30 0.33 0.30 0.33 Crude
alcohol mixture (in % by weight): First fraction 0.2 0.2 0.2 0.2
2-methylbutanol 4.6 13.1 9.9 6.5 n-pentanol 0.3 0.3 0.2 0.3
2-ethylhexanol 10.2 0.9 10.9 0.9 2-ethyl-4-methylhexanol 1.4 0.9
2.8 0.5 2-propylheptanol 19.0 6.6 17.6 7.0 2-ethylheptanol 18.5 6.4
16.9 6.7 2-propyl-4-methylhexanol 3.3 10.1 6.2 6.1 2-propylheptanol
40.6 59.6 33.2 69.8 Final fraction 1.9 1.9 2.1 2.0 Alcohol mixture
for plasticizer (in % by weight): 2-ethyl-4-methylhexanol 1.8 1.0
3.6 0.6 2-propylhexanol 22.9 7.9 23.0 7.8 2-ethylheptanol 22.3 7.6
22.0 7.4 2-propyl-4-methylhexanol 4.0 12.1 8.2 6.8 2-propylheptanol
49.0 71.4 43.2 77.4
[0038] The excellent gelling ability of the phthalic ester
plasticizers produced from the alcohol mixture of the invention is
shown by comparison with the established di(isodecyl) phthalate
(DIDP) plasticizers.
[0039] While only a limited number of specific embodiments of the
present invention have been expressly disclosed, it is,
nonetheless, to be broadly construed and not to be limited except
by the character of the claims appended hereto.
* * * * *