U.S. patent application number 12/699289 was filed with the patent office on 2010-06-03 for mixture of alicyclic polycarboxylic esters having high cis content.
This patent application is currently assigned to OXENO OLEFINCHEMIE GMBH. Invention is credited to Wilfried BUESCHKEN, Michael GRASS, Alfred KAIZIK, Dietrich MASCHMEYER, Franz NIERLICH, Axel TUCHLENSKI.
Application Number | 20100137486 12/699289 |
Document ID | / |
Family ID | 7699979 |
Filed Date | 2010-06-03 |
United States Patent
Application |
20100137486 |
Kind Code |
A1 |
BUESCHKEN; Wilfried ; et
al. |
June 3, 2010 |
MIXTURE OF ALICYCLIC POLYCARBOXYLIC ESTERS HAVING HIGH CIS
CONTENT
Abstract
The present invention relates to mixtures of alicyclic
polycarboxylic esters with high cis content, to a process for their
preparation by ring-hydrogenation of the corresponding aromatic
polycarboxylic esters, and also to the use of the mixtures.
Inventors: |
BUESCHKEN; Wilfried;
(Haltern am See, DE) ; GRASS; Michael; (Haltern am
See, DE) ; KAIZIK; Alfred; (Marl, DE) ;
MASCHMEYER; Dietrich; (Recklinghausen, DE) ;
TUCHLENSKI; Axel; (Muelheim, DE) ; NIERLICH;
Franz; (Marl, DE) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
OXENO OLEFINCHEMIE GMBH
Marl
DE
|
Family ID: |
7699979 |
Appl. No.: |
12/699289 |
Filed: |
February 3, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10489317 |
Aug 11, 2004 |
7683204 |
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PCT/EP2002/009732 |
Aug 30, 2002 |
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12699289 |
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Current U.S.
Class: |
524/285 ;
252/182.28 |
Current CPC
Class: |
C07C 69/75 20130101;
C07C 67/303 20130101; C07C 67/303 20130101; C08K 5/12 20130101;
C07C 69/75 20130101; C07C 2601/14 20170501 |
Class at
Publication: |
524/285 ;
252/182.28 |
International
Class: |
C08K 5/10 20060101
C08K005/10; C09K 3/00 20060101 C09K003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 24, 2001 |
DE |
101 46 848.2-44 |
Claims
1-15. (canceled)
16. An alicyclic polycarboxylic acid ester mixture, comprising: at
least two isomers of an alicyclic polycarboxylic acid ester whose
structures are determined by the positions of the ester groups on
the ring system of the ester compound, with the exception of
dimethyl 1,2-cyclohexanedicarboxylates, wherein the proportion of
the cis isomers in the isomer mixture is above 93 mol %, and
wherein the alicyclic polycarboxylic acid ester mixture is prepared
by hydrogenating the corresponding aromatic polycarboxylic acid
esters over a catalyst which comprises a precious metal of the
8.sup.th transition metal Group of the Periodic Table and at least
one metal of the 2.sup.nd transition Group of the Periodic
Table.
17. The alicyclic polycarboxylic acid ester mixture of claim 16,
wherein the ring system is a compound of one or more C.sub.6
rings.
18. The alicyclic polycarboxylic acid ester mixture of claim 16,
wherein the polycarboxylic esters have 2, 3 or 4 ester groups.
19. The alicyclic polycarboxylic acid ester mixture of claim 16,
wherein the alcohol components of the alicyclic polycarboxylic
esters are alkoxyalkyl, cycloalkyl, and/or alkyl groups having from
1 to 25 carbon atoms, are branched or unbranched, and are in each
instance identical or different.
20. The alicyclic polycarboxylic acid ester mixture of claim 16,
wherein the alicyclic polycarboxylic ester mixture comprises the
isomers of the cyclohexane-1,2-dicarboxylic acid esters,
1,3-dicarboxylic acid esters, or 1,4-dicarboxylic acid esters, or
the isomers of the cyclohexane-1,2,3-tricarboxylic acid esters,
1,2,4-tricarboxylic acid esters, or 1,3,5-tricarboxylic acid
esters.
21. A method of plasticizing a plastic material, comprising:
blending the alicyclic polycarboxylic acid ester mixture of claim
16 into a plastic material.
22. A plasticized material prepared by the method of claim 21.
23. The plasticized material of claim 22, wherein the amount of
alicyclic polycarboxylic acid ester in the plasticized material is
at least 5% by weight.
24. The alicyclic polycarboxylic acid ester mixture of claim 16,
wherein the alicyclic polycarboxylic ester mixture comprises at
least two isomers selected from the group consisting of
cyclohexane-1,2-dicarboxylic acid esters,
cyclohexane-1,3-dicarboxylic acid esters,
cyclohexane-1,4-dicarboxylic acid esters,
cyclohexane-1,2,3-tricarboxylic acid esters,
cyclohexane-1,2,4-tricarboxylic acid esters,
cyclohexane-1,3,5-tricarboxylic acid esters, and mixtures
thereof.
25. The alicyclic polycarboxylic acid ester mixture of claim 16,
wherein the alicyclic polycarboxylic ester mixture comprises at
least two isomers selected from the group consisting of
cyclohexane-1,2,3-tricarboxylic acid esters,
cyclohexane-1,2,4-tricarboxylic acid esters,
cyclohexane-1,3,5-tricarboxylic acid esters, and mixtures
thereof.
26. The alicyclic polycarboxylic acid ester mixture of claim 16,
wherein the alicyclic polycarboxylic ester mixture comprises at
least two isomers selected from the group consisting of
cyclohexane-1,2-dicarboxylic acid esters,
cyclohexane-1,3-dicarboxylic acid esters,
cyclohexane-1,4-dicarboxylic acid esters, and mixtures thereof.
27. The alicyclic polycarboxylic acid ester mixture of claim 16,
wherein the alicyclic polycarboxylic ester isomer mixture is
prepared by hydrogenating the corresponding
naphthalene-polycarboxylic acid ester isomers selected from the
group consisting of naphthalene-1,2-dicarboxylic acid esters,
naphthalene-1,3-dicarboxylic acid esters,
naphthalene-1,4-dicarboxylic acid esters,
naphthalene-1,5-dicarboxylic acid esters,
naphthalene-1,6-dicarboxylic acid esters,
naphthalene-1,7-dicarboxylic acid esters,
naphthalene-1,8-dicarboxylic acid esters, and mixtures thereof.
28. The alicyclic polycarboxylic acid ester mixture of claim 16,
wherein the alicyclic polycarboxylic ester isomer mixture is
prepared by hydrogenating the corresponding aromatic polycarboxylic
acid ester isomers selected from the group consisting of phthalic
acid (benzene-1,2-dicarboxylic acid ester), isophthalic acid
(benzene-1,3-dicarboxylic acid ester), terephthalic acid
(benzene-1,4-dicarboxylic acid ester),
benzene-1,2,3,4-tetracarboxylic acid, and mixtures thereof.
Description
[0001] The present invention relates to mixtures of alicyclic
polycarboxylic esters with high cis content, to a process for their
preparation by ring-hydrogenation of the corresponding aromatic
polycarboxylic esters, and also to the use of the mixtures.
[0002] Alicyclic polycarboxylic esters, such as the esters of
cyclohexane-1,2-dicarboxylic acid, are used as a component of
lubricating oil and as auxiliaries in metalworking. They are also
used as plasticizers for polyolefins.
[0003] For plasticizing PVC it is currently mainly esters of
phthalic acid that are used, for example dibutyl, dioctyl, dinonyl,
or didecyl esters. Since these phthalates have recently been
described as hazardous to health, there is a risk that their use in
plastics could become restricted. Alicyclic polycarboxylic esters,
some of which have been described in the literature as plasticizers
for various plastics, could then be available as suitable
replacements, although with a somewhat different performance
profile.
[0004] The most economic route to preparation of alicyclic
polycarboxylic esters in most cases is ring-hydrogenation of the
corresponding aromatic polycarboxylic esters, for example of the
abovementioned phthalates. Some processes for this purpose have
been disclosed:
[0005] U.S. Pat. No. 5,286,898 and U.S. Pat. No. 5,319,129 describe
a process which can hydrogenate dimethyl terephthalate on supported
Pd catalysts doped with Ni or with Pt and/or with Ru, at
temperatures of 140.degree. C. or above and at a pressure of from
50 to 170 bar, to give the corresponding dimethyl
hexahydroterephthalate.
[0006] DE 28 23 165 hydrogenates aromatic carboxylic esters on
supported Ni, Ru, Rh, and/or Pd catalysts to give the corresponding
alicyclic carboxylic esters at from 70 to 250.degree. C. and from
30 to 200 bar. U.S. Pat. No. 3,027,398 discloses the hydrogenation
of dimethyl terephthalate on supported Ru catalysts at from 110 to
140.degree. C. and from 35 to 105 bar.
[0007] WO 00/78704 discloses a process for hydrogenating
benzenepolycarboxylic esters to give the corresponding alicyclic
compounds. Here, use is made of supported catalysts which comprise
a metal of the 8th transition group alone or together with at least
one metal of the 1st or 7th transition group of the Periodic Table
and have 50% of macropores. Ruthenium is used as preferred metal of
the 8th transition group.
[0008] The ring-hydrogenation of aromatic polycarboxylic esters can
produce at least two isomers with respect to the ring system and to
the ester functions.
[0009] For example, the products from the hydrogenation of phthalic
diesters (benzene-1,2-dicarboxylic diesters) are cis- and/or
trans-cyclohexane-1,2-dicarboxylic diesters. The cis diester here
is the isomer in which one ester group has axial (a) orientation
and the other has equatorial (e) orientation. The trans compound is
the isomer in which both ester groups have either axial (a, a) or
equatorial (e, e) orientation.
[0010] Hydrogenation of isophthalic diesters
(benzene-1,3-dicarboxylic diesters) can produce cis- and
trans-cyclohexane-1,3-dicarboxylic diesters. In the cis compound
the ester groups have either axial-axial (a, a) or
equatorial-equatorial (e, e) orientation. In the trans compound one
ester group has axial orientation and the other has equatorial
orientation.
[0011] The hydrogenation of terephthalic diesters
(benzene-1,4-dicarboxylic diesters) can produce cis- and
trans-cyclohexane-1,4-dicarboxylic diesters. Here, in the cis
compound one ester group has axial orientation and the other has
equatorial orientation (a, e). In the trans compound both ester
groups have either axial (a, a) or equatorial (e, e)
orientation.
[0012] In the case of alicyclic polycarboxylic esters having more
than two substituents on the same ring system, each substituent can
have cis or trans configuration with respect to another
substituent. For the purposes of the present invention, all
compounds in which the majority of the ester groups have
transconfiguration with respect to one another are to be regarded
as trans compounds, irrespective of the other configurations of the
substituents with respect to one another.
[0013] The literature gives only sparse and incomplete information
concerning the configuration of the products which are produced
during the ring-hydrogenation of aromatic polycarboxylic
esters.
[0014] For example, according to U.S. Pat. No. 3,027,165 the
hydrogenation of dimethyl terephthalate on a ruthenium catalyst
produces a mixture of dimethyl cis- and
trans-cyclohexane-1,4-dicarboxylates with a melting point below
20.degree. C. It is known that the melting point of the trans
diester is 70.degree. C. and that the melting point of the cis
diester is 7.degree. C. Assuming conventional melting behavior (no
mixed crystal formation), i.e. that starting from one pure isomer
and adding the other isomer, the melting point of the mixture falls
until the eutectic point has been reached, it is possible to
estimate that the hydrogenation mixture is composed mainly of
dimethyl cis-cyclohexane-1,4-dicarboxylate.
[0015] S. Siegel and G. McCaleb in JACS, 81, 1959, pp. 3655-3658
describe the hydrogenation of dimethyl phthalates on suspended
platinum oxide powder in glacial acetic acid. Irrespective of the
pressure and concentration, the mixtures obtained of the
corresponding cyclohexanoic acid derivatives have practically 100
mol % cis content. The yields of the esters isolated are not
mentioned. This hydrogenation method has some disadvantages: the
catalyst has to be separated off from the hydrogenation mixture,
and experience has shown that losses of catalyst are unavoidable
here. The solvent used, glacial acetic acid, is highly corrosive
and therefore requires apparatus made from high-performance
materials. In addition, the glacial acetic acid, which makes up
from 80 to 90% of the hydrogenation discharge, has to be separated
off from the target product.
[0016] The preparation of dimethyl cyclohexanedicarboxylates with
high cis content is therefore known. However, that publication does
not disclose whether other carboxylic esters with high cis content
are also accessible via the published method or any other
method.
[0017] If the ruthenium-containing catalysts disclosed in WO
00/78704 are used for the hydrogenation of diisononyl phthalates,
the product mixture obtained has about 93 mol % of cis isomer and
correspondingly 7 mol % of the trans isomer.
[0018] There are therefore no known alicyclic polycarboxylic ester
mixtures with above 93 mol % content of the cis isomer(s), with the
exception of methyl cyclohexanedicarboxylates.
[0019] It was therefore an object of the present invention to
prepare mixtures of this type and to test their use as plasticizers
for plastics.
[0020] The invention therefore provides alicyclic polycarboxylic
ester mixtures, with the exception of methyl
cyclohexanedicarboxylates, comprising at least two isomers with
respect to the position of the ester groups on the ring system,
where the proportion of the cis isomers is above 93 mol %.
[0021] The mixtures of the invention are preferably prepared by
hydrogenating the corresponding aromatic polycarboxylic esters. For
this, use may be made of a catalyst which comprises at least one
precious metal of the 8th transition group of the elements and
comprises at least one metal of the 2nd transition group of the
Periodic Table.
[0022] The present invention also provides a process for preparing
alicyclic polycarboxylic ester mixtures which have at least two
isomers with respect to the position of the ester groups on the
ring system, and which have a proportion of the cis isomer above 93
mol %, by catalytic hydrogenation of the corresponding aromatic
polycarboxylic esters, where the catalyst comprises at least one
precious metal of the 8th transition group (ruthenium, rhodium,
palladium, osmium, iridium, platinum), and comprises at least one
metal of the 2nd transition group of the Periodic Table.
[0023] Among the abovementioned precious metals, preference is
given to ruthenium and very particularly to palladium. Zinc is used
as preferred metal of the 2nd transition group of the Periodic
Table.
[0024] Besides the precious metals mentioned and zinc, any of the
catalysts used in the process of the invention may also comprise
inert supports, e.g. those composed of the metals aluminum,
magnesium, titanium, zirconium, and/or silicon, in the form of
oxide or mixed oxide. The catalysts may optionally also comprise
salts of the support metals mentioned, for example sulfates and/or
phosphates. The catalysts used according to the invention may also
comprise processing aids or molding auxiliaries, for example
graphite.
[0025] The compositions given below are based on the reduced
catalysts.
[0026] The precious metal content of the catalysts (calculated as
metal) is in the range from 0.1 to 10% by weight, in particular in
the range from 0.5 to 5% by weight, very particularly from 1 to 3%
by weight.
[0027] The content (calculated as oxide) of metals of the 2nd
transition group, e.g. zinc, in the catalysts is from 3 to 70% by
weight, in particular from 10 to 50% by weight, very particularly
from 20 to 30% by weight.
[0028] The process of the invention particularly preferably uses
catalysts which in reduced, active form comprise at least some of
the precious metal in the oxidation state 0, and which preferably
comprise zinc in the oxidation state +2.
[0029] The catalysts are prepared by processes known per se, e.g.
by precipitation of carbonates, impregnation of previously prepared
supports, or mixing precursor compounds, and subsequent
calcination.
[0030] The catalysts are advantageously converted into a form which
has low resistance to flow during the hydrogenation process, for
example tablets, cylinders, extrudates, or rings.
[0031] The process of the invention preferably carries out the
hydrogenation in the liquid phase. The hydrogenation may be carried
out continuously or batchwise on catalysts arranged in suspension
or as pieces in a fixed bed. The process of the invention is
preferably continuous hydrogenation of the catalyst arranged in a
fixed bed, the product/starting material phase being primarily
liquid under the reaction conditions.
[0032] If the hydrogenation is carried out continuously on a
catalyst arranged in a fixed bed it is advantageous to convert the
catalyst into the active form prior to the hydrogenation process.
This may be achieved by reducing the catalyst, using
hydrogen-containing gases and a temperature program. This reduction
may, where appropriate, be carried out in the presence of a liquid
phase which trickles over the catalyst. The liquid phase used here
may comprise a solvent or the hydrogenation product.
[0033] Various versions of the process of the invention may be
selected. It may be carried out under adiabatic, polytropic, or
practically isothermal conditions, i.e. with a temperature rise
which is typically less than 10.degree. C., in one or more stages.
In the latter case it is possible for all of the reactors,
advantageously tubular reactors, to be operated under adiabatic or
practically isothermal conditions, or else for one or more to be
operated under adiabatic conditions and the others under
practically isothermal conditions. It is also possible for the
aromatic polycarboxylic esters to be hydrogenated in a straight
pass or with product return.
[0034] The process of the invention is carried out in the mixed
liquid/gas phase or liquid phase, concurrently in three-phase
reactors, the hydrogenation gas being distributed in a manner known
per se within the liquid starting material/product stream. To
promote uniform liquid distribution, improved dissipation of the
heat of reaction, and high space-time yield, the reactors are
preferably operated with high liquid flow rates of from 15 to 120,
in particular from 25 to 80, m.sup.3 per m.sup.2 of cross section
of the empty reactor per hour. If a reactor is operated with a
straight pass, the liquid hourly space velocity (LHSV) over the
catalyst may be from 0.1 to 10 h.sup.-1.
[0035] The hydrogenation may be carried out in the absence, or
preferably in the presence, of a solvent. Solvents which may be
used are any of the liquids which form a homogeneous solution with
the starting material and product, exhibit inert behavior under
hydrogenation conditions, and are easy to remove from the product.
The solvent may also be a mixture of two or more substances and,
where appropriate, comprise water.
[0036] Examples of substances which may be used as solvents are the
following: straight-chain or cyclic ethers, such as tetrahydrofuran
or dioxane, and also aliphatic alcohols whose alkyl radical has
from 1 to 13 carbon atoms.
[0037] Alcohols which may preferably be used are isopropanol,
n-butanol, isobutanol, n-pentanol, 2-ethylhexanol, nonanols,
industrial nonanol mixtures, decanol, and industrial decanol
mixtures, and tricedanols.
[0038] If alcohols are used as solvent it can be advantageous to
use the alcohol or alcohol mixture which would be produced during
saponification of the product. This would exclude by-product
formation via transesterification. Another preferred solvent is the
hydrogenation product itself.
[0039] By using a solvent it is possible to limit the concentration
of aromatic compounds in the reactor feed, and the result can be
better temperature control achieved in the reactor. This can
minimize side-reactions and therefore increase product yield. The
content of aromatic compounds in the reactor feed is preferably
from 1 to 35%, in particular from 5 to 25%. In the case of reactors
operated in loop mode, the desired concentration range can be
adjusted via the circulation rate (quantitative ratio of returned
hydrogenation discharge to starting material).
[0040] The process of the invention is carried out in the pressure
range from 3 to 300 bar, in particular from 15 to 200 bar, very
particularly from 50 to 200 bar. The hydrogenation temperatures are
from 50 to 220.degree. C., in particular from 100 to 200.degree.
C.
[0041] Hydrogenation gases which may be used are any desired
hydrogen-containing gas mixtures in which there are no detrimental
amounts present of catalyst poisons, such as carbon monoxide or
hydrogen sulfide. Examples of the inert gas constituents are
nitrogen and methane. It is preferable to use hydrogen at purity
greater than 95%, in particular greater than 98%.
[0042] The process of the invention can convert aromatic
polycarboxylic acids or derivatives of these, in particular their
alkyl esters, to the corresponding alicyclic polycarboxylic
compounds. In the case of the esters here, both full esters and
partial esters can be hydrogenated. Full esters are compounds in
which all of the acid groups have been esterified. Partial esters
are compounds having at least one free acid group (or, where
appropriate, one anhydride group) and at least one ester group.
[0043] The polycarboxylic esters of the invention and,
respectively, the polycarboxylic esters prepared by the process of
the invention preferably contain 2, 3, or 4 ester functions.
[0044] The polycarboxylic esters preferably used in the process of
the invention are benzene-, diphenyl-, naphthalene- and/or
anthracene polycarboxylic esters. The resultant alicyclic
polycarboxylic esters are composed of one or more C.sub.6 rings,
where appropriate linked by a carbon-carbon bond or fused.
[0045] Use may also optionally be made of polycarboxylic esters
having an underlying diphenyl oxide skeleton.
[0046] The alcohol component of the polycarboxylic esters is
preferably composed of branched or unbranched alkyl, cycloalkyl, or
alkoxyalkyl groups having from 1 to 25 carbon atoms. These may be
identical or different within one molecule of a polycarboxylic
ester, i.e. they may comprise identical or different isomers or
identical or different chain lengths.
[0047] In one preferred embodiment, the present invention provides
a process for the hydrogenation of benzene-1,2-, -1,3-, or
-1,4-dicarboxylic esters, and/or of benzene-1,2,3-, -1,2,4-, or
-1,3,5-tricarboxylic esters, i.e. the mixtures of the invention
comprise the isomers of cyclohexane-1,2-, -1,3-, or
-1,4-dicarboxylic esters, or of cyclohexane-1,2,3-, -1,3,5-, or
-1,2,4-tricarboxylic esters.
[0048] The following aromatic carboxylic acids may be used in the
process of the invention:
naphthalene-1,2-dicarboxylic acid, naphthalene-1,3-dicarboxylic
acid, naphthalene-1,4-dicarboxylic acid,
naphthalene-1,5-dicarboxylic acid, naphthalene-1,6-dicarboxylic
acid, naphthalene-1,7-dicarboxylic acid,
naphthalene-1,8-dicarboxylic acid, phthalic acid
(benzene-1,2-dicarboxylic acid), isophthalic acid
(benzene-1,3-dicarboxylic acid), terephthalic acid
(benzene-1,4-dicarboxylic acid), benzene-1,2,3-tricarboxylic acid,
benzene-1,2,4-tricarboxylic acid (trimellitic acid),
benzene-1,3,5-tricarboxylic acid (trimesic acid),
benzene-1,2,3,4-tetracarboxylic acid. It is also possible to use
acids which are produced from the acids mentioned by using alkyl,
cycloalkyl, or alkoxyalkyl groups to substitute one or more of the
hydrogen atoms bonded to the aromatic core.
[0049] It is possible to use alkyl, cycloalkyl, or else alkoxyalkyl
esters of the abovementioned acids, for example, these radicals
encompassing, independently of one another, from 1 to 25, in
particular from 3 to 15, very particularly from 8 to 13,
particularly 9, carbon atoms. These radicals may be linear or
branched. If a starting material has more than one ester group,
these radicals may be identical or different.
[0050] Examples of compounds which may be used in the process of
the invention as ester of an aromatic polycarboxylic acid are the
following:
monomethyl terephthalate, dimethyl terephthalate, diethyl
terephthalate, di-n-propyl terephthalate, dibutyl terephthalate,
diisobutyl terephthalate, di-tert-butyl terephthalate, monoglycol
terephthalate, diglycol terephthalate, n-octyl terephthalate,
diisooctyl terephthalate, di-2-ethylhexyl terephthalate, di-n-nonyl
terephthalate, diisononyl terephthalate, di-n-decyl terephthalate,
di-n-undecyl terephthalate, diisodecyl terephthalate, diisododecyl
terephthalate, ditridecyl terephthalate, di-n-octadecyl
terephthalate, diisooctadecyl terephthalate, di-n-eicosyl
terephthalate, monocyclohexyl terephthalate, monomethyl phthalate,
dimethyl phthalate, di-n-propyl phthalate, di-n-butyl phthalate,
diisobutyl phthalate, di-tert-butyl phthalate, monoglycol
phthalate, diglycol phthalate, di-n-octyl phthalate, diisooctyl
phthalate, di-2-ethylhexyl phthalate, di-n-nonyl phthalate,
diisononyl phthalate, di-n-decyl phthalate, di-2-propylheptyl
phthalate, diisodecyl phthalate, di-n-undecyl phthalate,
diisoundecyl phthalate, ditridecyl phthalate, di-n-octadecyl
phthalate, diisooctadecyl phthalate, di-n-eicosyl phthalate,
monocyclohexyl phthalate, dicyclohexyl phthalate, monomethyl
isophthalate, dimethyl isophthalate, diethyl isophthalate,
di-n-propyl isophthalate, di-n-butyl isophthalate, diisobutyl
isophthalate, di-tert-butyl isophthalate, monoglycol isophthalate,
diglycol isophthalate, di-n-octyl isophthalate, diisooctyl
isophthalate, 2-ethylhexyl isophthalate, di-n-nonyl isophthalate,
diisononyl isophthalate, di-n-decyl isophthalate, diisodecyl
isophthalate, di-n-undecyl isophthalate, diisododecyl isophthalate,
di-n-dodecyl isophthalate, ditridecyl isophthalate, di-n-octadecyl
isophthalate, diisooctadecyl isophthalate, di-n-eicosyl
isophthalate, monocyclohexyl isophthalate.
[0051] It is also possible to use mixtures made from two or more
polycarboxylic esters. Mixtures of this type may be obtained in the
following ways, for example: [0052] a) a polycarboxylic acid is
partially esterified using an alcohol in such a way as to give both
full and partial esters. [0053] b) A mixture of at least two
polycarboxylic acids is esterified using an alcohol, producing a
mixture of at least two full esters. [0054] c) A polycarboxylic
acid is treated with an alcohol mixture, and the product can be a
mixture of many full esters. [0055] d) A polycarboxylic acid may
also be partially esterified using an alcohol mixture. [0056] e) A
mixture of at least two carboxylic acids may also be partially
esterified using an alcohol mixture. [0057] f) A mixture of at
least two polycarboxylic acids may also be partially esterified
using an alcohol mixture.
[0058] Instead of the polycarboxylic acids in reactions a) to f),
use may also be made of their anhydrides.
[0059] Aromatic esters are often prepared industrially from alcohol
mixtures, in particular the full esters by route c).
[0060] Examples of corresponding alcohol mixtures are:
C.sub.5 alcohol mixtures prepared from linear butenes by
hydroformylation followed by hydrogenation; C.sub.5 alcohol
mixtures prepared from butene mixtures which comprise linear butene
and isobutene, by hydroformylation followed by hydrogenation;
C.sub.6 alcohol mixtures prepared from a pentene or from a mixture
of two or more pentenes, by hydroformylation followed by
hydrogenation; C.sub.7 alcohol mixtures prepared from triethylene
or dipropene or from a hexeneisomer or from some other mixture of
hexeneisomers, by hydroformylation followed by hydrogenation;
C.sub.8 alcohol mixtures, such as 2-ethylhexanol (2 isomers),
prepared by aldol condensation of n-butyraldehyde followed by
hydrogenation; C.sub.9 alcohol mixtures prepared from C.sub.4
olefins by dimerization, hydroformylation, and hydrogenation. The
starting materials here for preparing the C.sub.9 alcohols may be
isobutene or a mixture of linear butenes or mixtures of linear
butenes and isobutene. The O.sub.4 olefins may be dimerized with
the aid of various catalysts, such as protonic acids, zeolites,
organometallic nickel compounds, or solid nickel-containing
catalysts. The C.sub.8 olefin mixtures may be hydroformylated with
the aid of rhodium catalysts or cobalt catalysts. There is
therefore a wide variety of industrial C.sub.9 alcohol mixtures.
C.sub.10 alcohol mixtures prepared from tripropylene by
hydroformylation followed by hydrogenation; 2-propylheptanol (2
isomers) prepared by aldol condensation of valeraldehyde followed
by hydrogenation; C.sub.10 alcohol mixtures prepared from a mixture
of at least two C.sub.5 aldehydes by aldol condensation followed by
hydrogenation; C.sub.13 alcohol mixtures prepared from
hexaethylene, tetrapropylene, or tributene, by hydroformylation
followed by hydrogenation.
[0061] Other alcohol mixtures may be obtained by hydroformylation
followed by hydrogenation from olefins or olefin mixtures which
arise in Fischer-Tropsch syntheses, in the dehydrogenation of
hydrocarbons, in metathesis reactions, in the polygas process, or
in other industrial processes, for example.
[0062] Olefin mixtures with olefins of differing carbon numbers may
also be used to prepare alcohol mixtures.
[0063] The process of the invention can use any ester mixture
prepared from aromatic polycarboxylic acids and from the
abovementioned alcohol mixtures. According to the invention,
preference is given to esters prepared from phthalic acid or
phthalic anhydride and from a mixture of isomeric alcohols having
from 6 to 13 carbon atoms.
[0064] Examples of industrial phthalates which can be used in the
process of the invention are products with the following
tradenames:
Vestinol C (di-n-butyl phthalate) (CAS No. 84-74-2); Vestinol IB
(diisobutyl phthalate) (CAS No. 84-69-5); Jayflex DINP (CAS No.
68515-48-0); Jayflex DIDP (CAS No. 68515-49-1); Palatinol 9P
(68515-45-7), Vestinol 9 (CAS No. 28553-12-0); TOTM (CAS No.
3319-31-1); Linplast 68-TM, Palatinol N (CAS No. 28553-12-0);
Jayflex DHP (CAS No. 68515-50-4); Jayflex DIOP (CAS No.
27554-26-3); Jayflex UDP (CAS No. 68515-47-9); Jayflex DIUP (CAS
No. 85507-79-5); Jayflex DTDP (CAS No. 68515-47-9); Jayflex L9P
(CAS No. 68515-45-7); Jayflex L911P (CAS No. 68515-43-5); Jayflex
L11P
[0065] (CAS No. 3648-20-2); Witamol 110 (CAS No. 68515-51-5);
Witamol 118 (Di-n-C.sub.8-C.sub.10-alkyl phthalate) (CAS No.
71662-46-9); Unimoll BB (CAS No. 85-68-7); Linplast 1012 BP (CAS
No. 90193-92-3); Linplast 13XP (CAS No. 27253-26-5); Linplast 610P
(CAS No. 68515-51-5); Linplast 68 FP (CAS No. 68648-93-1); Linplast
812 HP (CAS No. 70693-30-0); Palatinol AH
[0066] (CAS No. 117-81-7); Palatinol 711 (CAS No. 68515-42-4);
Palatinol 911 (CAS No. 68515-43-5); Palatinol 11 (CAS No.
3648-20-2); Palatinol Z (CAS No. 26761-40-0); Palatinol DIPP (CAS
No. 84777-06-0); Jayflex 77 (CAS No. 71888-89-6); Palatinol 10 P
(CAS No. 533-54-0); Vestinol AH(CAS No. 117-81-7).
[0067] Reference is made below to the possible stereoisomers of the
alicyclic system, the trans form being differentiated from the cis
form. For example, as mentioned above, in the case of
cyclohexane-1,2-dicarbocylic esters the trans forms are the
compounds in which the ester groups have either axial-axial (a,a)
or equatorial-equatorial (e,e) orientation. In the cis compounds
one ester group has axial (a) orientation and the other has
equatorial (e) orientation. As stated above, other orientations may
apply for distinguishing between these two forms in the case of
other alicyclic polycarboxylic esters.
[0068] In particular versions of the process of the invention,
dinonyl phthalates or a mixture of isomeric dinonyl phthalates
is/are hydrogenated to give a mixture of isomeric dinonyl
cyclohexane-1,2-dicarboxylates, the proportion of the cis isomer
with respect to the position of the carboxy groups on the
cyclohexane ring being above 93 mol %.
[0069] Similarly, di(2-ethylhexyl) phthalates may be reacted to
give di(2-ethylhexyl)cyclohexane-1,2-dicarboxylates, or didecyl
phthalates may be reacted to give didecyl
cyclohexane-1,2-dicarboxylates. With respect to the cis/trans
isomers, what has been said for the isononyl ester is again
applicable.
[0070] The mixtures of the invention or mixtures prepared according
to the invention comprise above 93 mol %, based on the entire
amount of ester, of cis compound(s). The mixtures preferably
comprise from 94 to 100 mol %, from 95 to 100 mol %, from 96 to 100
mol %, from 97 to 100 mol %, from 98 to 100 mol %, or from 99 to
100 mol %, of the cis isomer(s).
[0071] The present invention also provides the use of the alicyclic
polycarboxylic esters of the invention or prepared according to the
invention as a plasticizer in plastics. Preferred plastics are PVC,
homo- and copolymers based on ethylene, on propylene, on butadiene,
on vinyl acetate, on glycidyl acrylate, on glycidyl methacrylate,
on acrylates, or on acrylates having, bonded to the oxygen atom of
the ester group, alkyl radicals of branched or unbranched alcohols
having from one to ten carbon atoms, or on styrene or on
acrylonitrile, and homo- or copolymers of cyclic olefins.
[0072] The following plastics may be mentioned as representatives
of the above groups:
polyacrylates having identical or different alkyl radicals having
from 4 to 8 carbon atoms, bonded to the oxygen atom of the ester
group, in particular having the n-butyl, n-hexyl, n-octyl, or
2-ethylhexyl radical, polymethacrylate, polymethyl methacrylate,
methyl acrylate-butyl acrylate copolymers, methyl
methacrylate-butyl methacrylate copolymers, ethylene-vinyl acetate
copolymers, chlorinated polyethylene, nitrile rubber,
acrylonitrile-butadiene-styrene copolymers, ethylene-propylene
copolymers, ethylene-propylene-diene copolymers,
styrene-acrylonitrile copolymers, acrylonitrile-butadiene rubber,
styrene-butadiene elastomers, and methyl
methacrylate-styrene-butadiene copolymers.
[0073] The alicyclic polycarboxylic esters of the invention may
moreover be used to modify plastics mixtures, for example the
mixture of a polyolefin with a polyamide.
[0074] The present invention also provides mixtures made from
plastics with the alicyclic polycarboxylic esters of the invention,
or prepared according to the invention. Suitable plastics are the
abovementioned compounds. These mixtures preferably comprise at
least 5% by weight, particularly preferably from 20 to 80% by
weight, very particularly preferably from 30 to 70% by weight, of
the alicyclic polycarboxylic esters.
[0075] Mixtures made from plastics, in particular PVC, and
comprising one or more of the alicyclic polycarboxylic esters of
the invention, may be present in the following products, for
example:
casings for electrical devices, such as kitchen appliances,
computer cases, casings and components of phonographic and
television equipment, of piping, of apparatus, of cables, of wire
sheathing, of insulating tapes, of window profiles, in interior
decoration, in vehicle construction and furniture construction,
plastisols, in floor coverings, medical products, packaging for
food or drink, gaskets, films, composite films, phonographic disks,
synthetic leather, toys, containers for packaging, adhesive-tape
films, clothing, coatings, and fibers for fabrics.
[0076] Mixtures made from plastics, in particular PVC, and
comprising one or more of the alicyclic polycarboxylic esters of
the invention may moreover be used for producing the following
products, for example:
a casing for electrical devices, piping, apparatus, a cable, wire
sheathing, a window profile, a floor covering, a medical product, a
toy, packaging for food or drink, a gasket, a film, a composite
film, a phonographic disk, synthetic leather, a container for
packaging, an adhesive-tape film, clothing, a coating, or a fiber
for fabrics.
[0077] Besides the abovementioned applications, the alicyclic
polycarboxylic esters of the invention may be used as a component
in lubricating oil, or as a constituent of coolants or metal
working fluids.
[0078] The examples below are intended to illustrate the invention
without restricting the scope of protection defined by the patent
claims.
[0079] Analysis:
[0080] The ratio of cis- and trans-cyclohexane-1,2-dicarboxylic
diesters was determined by .sup.1H NMR spectroscopy.
TABLE-US-00001 Measuring device: Avance DPX-360 NMR spectrometer
from the company Bruker Measurement frequency: 360 MHz Sample head:
QNP sample head, 5 mm Solvent: CDCl.sub.3 (degree of deuteration
99.8%) Standard: Tetramethylsilane (TMS) Measurement temperature:
303 K Number of scans: 32 Delay: 1 s Acquisition time: 4.4 s
Spectral width: 7440.5 Hz Pulse angle: 30.degree. Pulse length: 3.2
.mu.s
[0081] An example of the method of recording the .sup.1H NMR
spectra comprised dissolving about 20 mg of the specimen in about
0.6 ml of CDCl.sub.3 (with 1% by weight of TMS). The spectra were
recorded under the conditions given above and referenced to TMS=0
ppm.
[0082] In the .sup.1H NMR spectra obtained, the methyne signals for
dialkyl cis- and trans-hexahydrophthalates could be distinguished
with chemical shifts of about 2.8 ppm and 2.6 ppm, respectively,
the signal shifted toward lower field corresponding to the cis
compound (larger ppm value). To quantify the isomers, the integrals
were determined from 3.0 ppm to 2.7(2) ppm and from 2.7(2) ppm to
2.5 ppm, the two integrals being separated in the middle between
the signals. The ratio of the two isomeric structures could be
determined from the intensity ratios.
EXAMPLE 1
Comparative Example
[0083] The catalyst used comprised catalyst H 14184 (0.5% of Ag on
transition alumina in the form of extrudates of diameter 1.2 mm)
from Degussa. 57 g of catalyst were placed in a rotating basket in
a stirred autoclave and reduced in accordance with the
manufacturer's instruction in hydrogen at 4 bar and 200.degree. C.
The autoclave was then filled with 600 g of diisononyl phthalate
(abbreviated to DINP, the product Vestinol 9 from Oxeno GmbH), and
hydrogen was applied at a pressure of 200 bar. Hydrogenation was
then carried out at a temperature of 120.degree. C. for 70 hours.
DINP conversion was complete. The proportion of diisononyl
cis-cyclohexanedicarboxylate (cis-DINCH) in the product was found
to be 85%, the remainder being trans-DI NCH.
EXAMPLE 2
Comparative Example
[0084] The experiment of example 1 was repeated, except that in
this the reaction temperature was raised to 200.degree. C. and the
hydrogenation time shortened to 21.2 h. Conversion was again
complete, but this time the cis-DINCH content was only 81.4%.
Although the very high reaction temperature achieved a high
reaction rate, isomeric selectivity reduced markedly.
EXAMPLE 3
Inventive
[0085] The catalyst used comprised catalyst H 14184 (0.5% of Pd on
transition alumina in the form of extrudates of diameter 1.2 mm)
from Degussa AG, which had also been doped with 2% ZnO. 59 g of
catalyst were placed in a rotating basket in a stirred autoclave
and reduced in accordance with the manufacturer's instruction in
hydrogen at 4 bar and 200.degree. C. The autoclave was then filled
with 600 g of diisononyl phthalate (abbreviated to DINP, the
product Vestinol 9 from Oxeno GmbH), and hydrogen was applied at a
pressure of 200 bar. Hydrogenation was then carried out at a
temperature of 120.degree. C. for 60 hours. DINP conversion was
complete. The proportion of diisononyl cis-cyclohexanedicarboxylate
(cis-DINCH) in the product was found to be 97.2%, the remainder
being trans-DINCH.
EXAMPLE 4
Comparative Example
[0086] The catalyst used comprised 1.0% of Ru on --Al.sub.2O.sub.3
in the form of beads of diameter 3 mm. 74 g of catalyst were placed
in a rotating basket in a stirred autoclave and reduced in
accordance with the manufacturer's instruction in hydrogen at 4 bar
and 200.degree. C. The autoclave was then filled with 600 g of
diisononyl phthalate (abbreviated to DINP, the product Vestinol 9
from Oxeno GmbH), and hydrogen was applied at a pressure of 200
bar. Hydrogenation was then carried out at a temperature of
120.degree. C. for 22 hours. DINP conversion was complete. The
proportion of diisononyl cis-cyclohexanedicarboxylate (cis-DINCH)
in the product was found to be 93.6%, the remainder being
trans-DINCH.
EXAMPLE 5
Inventive
[0087] The experiment of example 4 was repeated under the same
conditions, except that in this case use was made of a catalyst
which had also been doped with 2.5% of ZnO. Conversion was again
complete, and cis-DINCH content was 97.3%.
* * * * *