U.S. patent application number 10/317546 was filed with the patent office on 2003-05-22 for preparation of polyetherols by ring-opening polymerization of alkylene oxides.
This patent application is currently assigned to BASF Aktiengesellschft. Invention is credited to Grosch, Georg Heinrich, Harre, Kathrin, Junge, Dieter, Larbig, Harald, Lorenz, Reinhard.
Application Number | 20030097027 10/317546 |
Document ID | / |
Family ID | 7879945 |
Filed Date | 2003-05-22 |
United States Patent
Application |
20030097027 |
Kind Code |
A1 |
Grosch, Georg Heinrich ; et
al. |
May 22, 2003 |
Preparation of polyetherols by ring-opening polymerization of
alkylene oxides
Abstract
A process for preparing polyetherols by ring-opening
polymerization of alkylene oxides onto H-functional initiator
molecules, which comprises at least one process step a) in which a
compound of the formula (I)
M'.sub.aM".sub.b(OH).sub.cO.sub.d*A.sub.c*L.sub.f (I), applied to a
solid inert support or incorporated in the latter or molded to form
a shaped body is used as catalyst, and at least one process step b)
in which a multimetal cyanide compound of the formula (II)
M.sup.1.sub.a[M.sup.2(CN).sub.b(A).sub.c].sub.d.fM.sup.1.sub.gX.sub.n.h(H.-
sub.2O).eL (II) applied to a solid, inert support or incorporated
in the latter or molded to form a shaped body or in powder or paste
form is used as catalyst.
Inventors: |
Grosch, Georg Heinrich; (Bad
Durkheim, DE) ; Larbig, Harald; (Ludwigshafen,
DE) ; Lorenz, Reinhard; (Limburgerhof, DE) ;
Junge, Dieter; (Frankenthal, DE) ; Harre,
Kathrin; (Dresden, DE) |
Correspondence
Address: |
FERNANDO A. BORREGO
BASF CORPORATION
LEGAL DEPARTMENT
1609 BIDDLE AVENUE
WYANDOTTE
MI
48192
US
|
Assignee: |
BASF Aktiengesellschft
|
Family ID: |
7879945 |
Appl. No.: |
10/317546 |
Filed: |
December 12, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10317546 |
Dec 12, 2002 |
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09744512 |
Jan 24, 2001 |
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09744512 |
Jan 24, 2001 |
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PCT/EP99/06222 |
Aug 25, 1999 |
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Current U.S.
Class: |
568/679 ;
528/76 |
Current CPC
Class: |
B01J 27/232 20130101;
B01J 27/236 20130101; C08G 65/269 20130101; C08G 65/2657 20130101;
B01J 23/007 20130101; C08G 65/2642 20130101; C08G 65/2663 20130101;
B01J 27/26 20130101 |
Class at
Publication: |
568/679 ;
528/76 |
International
Class: |
C07C 041/03; C08G
018/30 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 5, 1998 |
DE |
19840585.5 |
Claims
We claim:
1. A process for preparing polyetherols by ring-opening
polymerization of alkylene oxides onto H-functional initiator
molecules, which comprises at least one process step a) in which a
compound of the formula (I)
M'.sub.aM".sub.b(OH).sub.cO.sub.d*A.sub.e*L.sub.f (I), where M' is
a metal ion selected from groups IA, IIA of the Periodic Table and
Ni or Zn, and mixtures thereof, M" is a metal ion selected from
groups IIIA, IVA, IB to VIIIB of the Periodic Table and As, Sb and
Bi, and mixtures thereof, A is at least one singly charged or
multiply charged, inorganic or organic anion, L is at least one
inorganic or organic ligand, where a is a rational number greater
than zero, b, c, d, e, f are rational numbers greater than or equal
to zero, c and d must not simultaneously be zero, a, b, c, d, e and
f are selected such that the compound is electrically neutral,
applied to a solid inert support or incorporated in the latter or
molded to form a shaped body is used as catalyst, and at least one
process step b) in which a multimetal cyanide compound of the
formula (II)
M.sup.1.sub.a[M.sup.2(CN).sub.b(A).sub.c].sub.d.fM.sup.1.sub-
.gX.sub.n.h(H.sub.2O).eL (II) where M.sup.1 is at least one metal
ion selected from the group consisting of Zn2+, Fe2+, Co3+, Ni2+,
Mn2+, Co2+, Sn2+, Pb2+, Mo4+, Mo6+, Al3+, V4+, V5+, Sr2+, W4+, W6+,
Cr2+, Cr3+, Cd2+, M.sup.2 is at least one metal ion selected from
the group consisting of Fe2+, Fe3+, Co2+, Co3+, Mn2+, Mn3+, V4+,
V5+, Cr2+, Cr3+, Rh3+, Ru2+, Ir3+and M.sup.1 and M.sup.2 are
identical or different, A is at least one anion selected from the
group consisting of halide, hydroxide, sulfate, carbonate, cyanide,
thiocyanate, isocyanate, cyanate, carboxylate, oxalate and nitrate,
X is at least one anion selected from the group consisting of
halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate,
isocyanate, cyanate, carboxylate, oxalate and nitrate, L is at
least one water-miscible ligand selected from the group consisting
of alcohols, aldehydes, ketones, ethers, polyethers, esters, ureas,
amides, nitriles and sulfides, and a, b, c, d, g and n are selected
such that the compound is electrically neutral, and e is the
coordination number of the ligand, e and f are fractional numbers
or integers greater than or equal to 0 h is a fractional number or
integer greater than or equal to 0, applied to a solid, inert
support or incorporated in the latter or molded to form a shaped
body or in powder or paste form is used as catalyst.
2. A process as claimed in claim 1, wherein alkylene oxide is first
added onto the initiator molecule in a process step a) and a
process step b) is then carried out.
3. A process as claimed in claim 1, wherein alkylene oxide is first
added onto the initiator molecule in a process step a), a process
step b) is then carried out and another process step a) is carried
out subsequently.
4. A process as claimed in claim 1, wherein the alkylene oxide used
in process step a) is ethylene oxide and/or propylene oxide and the
alkylene oxide used in process step b) is propylene oxide.
5. A process as claimed in claim 1, wherein the alkylene oxide used
for carrying out process step a) at the end of the process is
ethylene oxide.
6. A polyetherol having a functionality of from 1 to 8 and a molar
mass of from 200 to 100,000 which can be prepared by a process as
claimed in any of claims 1 to 5.
7. The use of a polyetherol as claimed in claim 6 for producing
polyurethanes.
Description
[0001] Preparation of polyetherols by ring-opening polymerization
of alkylene oxides
[0002] The present invention relates to a process for preparing
polyether alcohols by ring-opening polymerization of alkylene
oxides and to the use of the polyetherols.
[0003] Polyether alcohols are important starting materials in the
production of polyurethanes. They are usually prepared by catalytic
addition of lower alkylene oxides, in particular ethylene oxide
and/or propylene oxide, onto H-functional initiator molecules.
[0004] At present, the preparation of polyether alcohols is carried
out in batch processes in which the catalyst is suspended in the
initiator substance.
[0005] Catalysts used are usually soluble basic metal hydroxides or
salts, with potassium hydroxide having the greatest industrial
importance. The major disadvantage of the use of potassium
hydroxide as catalyst is that in the preparation of high molecular
weight polyether alcohols it results in the formation of
unsaturated by-products which reduce the functionality of the
polyether alcohols and have a very adverse effect in the production
of polyurethanes.
[0006] To lower the amount of unsaturated constituents in the
product, EP-A 268 922 has proposed using cesium hydroxide as
catalyst. However, the use of the expensive cesium hydroxide as
catalyst makes the process less economical. Basic metal hydroxides
which dissolve in the polyether polyols, e.g. potassium hydroxide
and cesium hydroxide, have the further disadvantage that they have
to be extracted from the polyetherol at great cost after the
synthesis and the resulting waste has to be disposed of.
[0007] Another class of substances which are likewise suitable as
catalysts for the preparation of polyether polyols is sparingly
soluble basic oxides or hydroxides. Such basic oxides or hydroxides
can be, for example, alkaline earth metal oxides or hydroxides.
Thus, U.S. Pat. No. 5,679,764 describes the use of relatively
coarse magnesium oxide powders as alkoxylation catalyst. The use of
doped basic alkaline earth metal oxides or hydroxides, for example
hydrotalcite, has also been described. A whole series of patents
describes the preparation of fatty alcohol ethoxylates having a
narrow molecular weight distribution using calcined or
hydrophobicized hydrotalcite as catalyst. Representative examples
of the large number of these patents are: DE-A 4 242 017, DE-A 4
137 317, DE-A 4 122 200, DE-A 4 115 149, DE-A 4 034 305, WO-A 94/11
331, WO-A 92/11 224, U.S. Pat. No. 4 962 237.
[0008] According to the patents cited, the alkoxylation of low
molecular weight initiator substances is carried out using a
suspension procedure. Use is made of more or less coarse powders
which in most cases can be removed from the product only with great
technical effort.
[0009] Catalysts comprising alkaline earth metal oxide/hydroxide
can readily alkoxylate low molecular weight initiator substances
and also readily ethoxylate high molecular weight initiator
substances, but the reaction rate in the propoxylation of initiator
substances having an intermediate molecular weight is very low.
[0010] To reduce the amount of unsaturated components in the
polyether alcohols and to increase the reaction rate in the
molecular addition of propylene oxide, the use of multimetal
cyanide compounds, in particular zinc hexacyanometalates, as
catalysts has been proposed. There is a large number of
publications in which such compounds have been described. Thus,
DD-A-203 734 and DD-A-203 735 describe a process for preparing
polyether alcohols using zinc hexacyanocobaltate.
[0011] The preparation of the zinc hexacyanometalates is also
known. It is usually carried out by reacting solutions of metal
salts, usually zinc chloride, with solutions of alkali metal or
alkaline earth metal cyanometalates, e.g. potassium
hexacyanocobaltate. A water-miscible component containing one or
more heteroatoms is normally added to the resulting precipitation
suspension immediately after the precipitation procedure. This
heteroatom-containing component can already be present in one or
both starting solutions. The water-miscible, heteroatom-containing
component is preferably an ether, polyether, alcohol, ketone or a
mixture of at least two of the compounds mentioned. Such processes
are described, for example, in U.S. Pat. No. 3,278,457, U.S. Pat.
No. 3,278,458, U.S. Pat. No. 3,278,459, U.S. Pat. No.
3,427,256.
[0012] DD-A-148 957 describes the preparation of zinc
hexacyanoiridate and its use as catalyst in the preparation of
polyether alcohols. Here, hexacyanoiridic acid is used instead of
the corresponding salt as one of the starting materials. The
multimetal cyanide compounds prepared by means of an acid usually
have a higher activity than those prepared from hexacyanometalate
salts.
[0013] While multimetal cyano catalysts display high activities in
the propoxylation of initiator molecules having molar masses
greater than 400 dalton and can propoxylate them to give high
molecular weight products, the reaction of low molecular weight
initiator molecules is associated with considerable
difficulties.
[0014] A particular disadvantage in the industrial use of
multimetal cyanide catalysts is that the alkoxylation of low
molecular weight initiator molecules is very difficult. There is
often a delayed commencement of the reaction resulting in addition
of too much alkylene oxide at the beginning. This can, apart from
reducing the space-time yield, lead to serious safety problems in
the production plants.
[0015] A further problem associated with the use of multimetal
cyano catalysts is that the addition of ethylene oxide onto both
high molecular weight and low molecular weight initiator molecules,
for example to prepare polyetherols having ethylene oxide end
blocks as are used, inter alia, for producing HR polyurethane
foams, is not possible and the use of multimetal cyanide catalysts
is therefore restricted to particular polyetherols.
[0016] A simple combination of both catalysts in one process by
first reacting the initiator substance with alkylene oxide in the
presence of a basic catalyst as far as a molecular weight at which
a double metal cyanide catalyst can be used and then continuing the
reaction using a double metal cyanide catalyst founders because,
inter alia, the basic catalyst has to be removed virtually
quantitatively since it acts as a catalyst poison for the
multimetal cyanide catalysts. Even the alkali metal hydroxide
contents remaining in the polyether alcohol after the customary
work-up are too high for this purpose. When using insoluble
catalysts suspended in the polyetherol, their removal is very
difficult to carry out industrially if these catalysts have not
been appropriately conditioned. In addition, the purification step
during the preparation of polyetherols is an additional process
step which leads to product losses, to a reduction in the
space-time yield and to formation of waste materials which have to
be disposed of.
[0017] It is an object of the present invention to develop a
process for preparing polyether polyols which leads to polyetherols
having a low content of unsaturated components, in which process
the molecular addition of propylene oxide proceeds at a high
reaction rate from reaction commencement to high molar masses and
in which the incorporation of ethylene oxide end blocks can be
carried out.
[0018] We have found that this object is achieved by a process for
preparing polyetherols by ring-opening polymerization of alkylene
oxides onto H-functional initiator molecules, which comprises at
least one process step a) in which a compound of the formula
(I)
M'.sub.aM".sub.b (OH).sub.cO.sub.d*A.sub.e*L.sub.f (I),
[0019] where
[0020] M' is a metal ion selected from groups IA, IIA of the
Periodic Table and Ni or Zn, and mixtures thereof,
[0021] M" is a metal ion selected from groups IIIA, IVA, IB to
VIIIB of the Periodic Table and As, Sb and Bi, and mixtures
thereof,
[0022] A is at least one singly charged or multiply charged,
inorganic or organic anion,
[0023] L is at least one inorganic or organic ligand,
[0024] where
[0025] a is a rational number greater than zero,
[0026] b, c, d, e, f are rational numbers greater than or equal to
zero,
[0027] c and d must not simultaneously be zero,
[0028] a, b, c, d, e and f are selected such that the compound is
electrically neutral,
[0029] applied to a solid inert support or incorporated in the
latter or molded to form a shaped body is used as catalyst,
[0030] and at least one process step b) in which a multimetal
cyanide compound-of the formula (II)
M.sup.1.sub.a[M.sup.2(CN).sub.b(A).sub.c].sub.d.fM.sup.1.sub.gX.sub.n.h(H.-
sub.2O).eL (II)
[0031] where
[0032] M.sup.1 is at least one metal ion selected from the group
consisting of Zn2+, Fe2+, Co3+, Ni2+, Mn2+, Co2+, Sn2+, Pb2+, Mo4+,
Mo6+, Al3+, V4+, V5+, Sr2+, W4+, W6+, Cr2+, Cr3+, Cd2+,
[0033] M.sup.2 is at least one metal ion selected from the group
consisting of Fe2+, Fe3+, Co2+, Co3+, Mn2+, Mn3+, V4+, V5+, Cr2+,
Cr3+, Rh3+, Ru2+, Ir3+
[0034] and M.sup.1 and M.sup.2 are identical or different,
[0035] A is at least one anion selected from the group consisting
of halide, hydroxide, sulfate, carbonate, cyanide, thio-cyanate,
isocyanate, cyanate, carboxylate, oxalate and nitrate,
[0036] X is at least one anion selected from the group consisting
of halide, hydroxide, sulfate, carbonate, cyanide, thio-cyanate,
isocyanate, cyanate, carboxylate, oxalate and nitrate,
[0037] L is at least one water-miscible ligand selected from the
group consisting of alcohols, aldehydes, ketones, ethers,
polyethers, esters, ureas, amides, nitriles and sulfides,
[0038] and
[0039] a, b, c, d, g and n are selected such that the compound is
electrically neutral, and
[0040] e is the coordination number of the ligand,
[0041] e and f are fractional numbers or integers greater than or
equal to 0
[0042] h is a fractional number or integer greater than or equal to
0,
[0043] applied to a solid, inert support or incorporated in the
latter or molded to form a shaped body or in powder or paste form
is used as catalyst.
[0044] A process step a) is preferably carried out at the beginning
of the reaction since the reaction rate in the alkylene oxide
polymerization at the beginning of the reaction is greatest when
using the catalysts of the formula (I). After reaching a molecular
weight of preferably at least 400 dalton, a reaction step b)
follows. This can extend to the end of the alkylene oxide addition
reaction. However, it is also possible to add another reaction step
a). This can be useful, for example, if an ethylene oxide block is
to be added on, preferably at the end of the chain. The
introduction of a reaction step b) can also be found to be useful
if an ethylene oxide block is to be introduced within the chain and
further propylene oxide is to be added on subsequently. The
molecular addition of the propylene oxide can be carried out by
means of process step b).
[0045] The process of the present invention for preparing polyether
polyols can be carried out either as a suspension process or a
fixed-bed process. If the process is carried out in the suspension
mode, the removal of the catalyst has to be very simple in each
individual step. It is preferred that the catalyst can be separated
from the polyether polyol in each individual step by simple
filtration or centrifugation operations. This can be achieved, for
example, by the size of the catalyst particles being sufficiently
large or by appropriate additions of filter aids. However,
particular preference is given to the fixed-bed method. For this
purpose, the catalysts used have to be immobilized so that they
remain in the reactor and, if possible, only simple filtration
operations are necessary to remove suspended material.
[0046] Catalysts-used in step a) are, as indicated, compounds of
the formula (I)
M'.sub.aM".sub.b(OH).sub.cO.sub.d*A.sub.e*L.sub.f (I),
[0047] where the symbols are as defined above.
[0048] The compounds of the formula (I) can be used as powder or
coarser granules in a suspension process. However, the active
compositions for step a) and b) are preferably applied to solid
supports, incorporated in the latter or molded to form shaped
bodies.
[0049] The supports for the catalysts of the formula (I) used
according to the present invention are macroscopic shaped bodies as
are customary and known as catalyst supports, e.g. extrudates,
granules, pellets, meshes, packing elements, woven fabrics, fibers,
spheres and also the inner walls of reactors. The macroscopic
shaped bodies can consist of inorganic and/or organic materials.
Inorganic materials are, for example, oxides, carbides, nitrides or
inert metals. Examples of carbides are transition metal carbides
such as tungsten carbide, and also silicon carbide and boron
carbide. Suitable nitrides are, for example, boron nitride, silicon
nitride and aluminum nitride. For the purposes of the present
invention, inert metals are metals or metal alloys which are inert
toward the reaction medium in the polyether alcohol synthesis.
Examples of inert metals are steels, aluminum, noble metals,
nickel, stainless steels, titanium, tantalum and Kanthal. As
oxides, it is possible to use metal oxides which are inert under
said reaction conditions, particularly those of metals of groups
IIA to IVA and IB to VIIIB, and also oxidic compounds comprising
elements of groups IA to VIIA and/or the metals of groups IB to
VIIIB.
[0050] The catalysts of the present invention can be produced by
applying the compounds of type (I) to the surface of the shaped
supports or-by mixing compounds of type (I) with unmolded support
material and subsequent shaping. It is also possible to mold
pulverulent compounds of type (I) to produce unsupported catalysts.
These unsupported catalysts can then be further processed to give
coarser granules in order to be used, if desired, in a suspension
process.
[0051] For preparing compounds of type (I), there is a large number
of methods and possibilities.
[0052] Thus, these compounds can be prepared by coprecipitation.
For this purpose, a solution containing all the desired metal ions
is made up and the ions are precipitated by addition of further
reagents, for example by altering the pH by addition of a base. The
precipitated solids can also be subjected to a hydrothermal
treatment to induce further crystallization.
[0053] Intimate mixing of the components by evaporation of the
joint solution on a rotary evaporator is also possible.
[0054] The materials prepared in this way can subsequently be dried
and calcined.
[0055] Such compounds can also be prepared by impregnation or
steeping. For this purpose, a solid which already comprises at
least one of the desired components is treated with at least one
solution which can comprise the other metal ions. After taking off
the solvent, a drying and/or calcination step can likewise be
carried out.
[0056] The solids obtained in this way can then be subjected to
further treatments with organic or inorganic ligands.
[0057] Preferred compounds of type (I) are those in which M'
comprises alkaline earth metal ions or zinc ions. Specific
compounds which may be mentioned here are the pure oxides and
hydroxides, for example magnesium oxide, calcium oxide, strontium
oxide, barium oxide, zinc oxide, magnesium hydroxide, calcium
hydroxide, strontium hydroxide, barium hydroxide or zinc hydroxide.
However, apart from the pure oxides and hydroxides, there is a
broad range of possible dopants, both on the cation and anion
sides.
[0058] Doping with other cations such as the main group elements
boron, aluminum, gallium, indium, thallium, silicon, germanium,
tin, lead, arsenic, antimony and bismuth and also the transition
elements of groups IB to VIIIB, in particular chromium, iron,
lanthanum, manganese, scandium, yttrium, titanium and vanadium,
enables a large number of compounds to be prepared.
[0059] Anions which can be used are inorganic anions, for example
halides and sulfur- phosphorus-, nitrogen- or carbon-containing
anions, and also organic anions such as alkoxides, carboxylates,
amides and sulfides and many more.
[0060] Doping of the pure oxides or hydroxides gives a large number
of compounds. Only a few examples will be given here:
[0061] Hydrotalcite [Mg.sub.6Al.sub.2(OH).sub.16]CO.sub.3.4
H.sub.2O)
[0062] Takovite [Ni.sub.6Al.sub.2(OH).sub.16]CO.sub.3.4
H.sub.2O
[0063] Stichtite [Mg.sub.6Cr.sub.2(OH).sub.16]CO.sub.3.4
H.sub.2O
[0064] Hydrocalumite [Ca.sub.2Al(OH).sub.6]OH .6 H.sub.2O
[0065] Magaldrate [Mg.sub.10Al.sub.5(OH).sub.31](SO.sub.4).sub.2.m
H.sub.2O
[0066] Pyroaurite [Mg.sub.6Al.sub.2(OH).sub.16]CO.sub.3.4.5
H.sub.2O
[0067] Ettringite [Ca.sub.6Al.sub.2(OH).sub.12](SO.sub.4).sub.3.26
H.sub.2O
[0068] The solids prepared as described above can be crystalline or
amorphous. Crystalline compounds can be layer-lattice compounds
such as hydrotalcite.
[0069] There are a number of methods which can be employed for
molding the compounds of the formula (I).
[0070] One method of applying the compounds of the formula (I) to
an inert shaped body comprises spraying a suspension of these
compounds in an inert liquid. As a suspension for spraying, it is
possible to use either the precipitation slurry of the compounds or
the previously synthesized and possibly dried compound, suspended
in a suitable suspension medium.
[0071] To increase the adhesion of the sprayed-on compound of type
I to the shaped body, additional inorganic materials which act as
binder can be added to the suspension for spraying.
[0072] The shaped bodies produced in this way can then be subjected
to a calcination step. This can both have a positive effect on the
adhesion to the shaped body and can also promote the formation of
the active phase.
[0073] Furthermore, inorganic or organic materials which can react
either thermally or photochemically, i.e. become crosslinked and
thus enable the active composition to adhere strongly to the
support, can be added in pure form, in the form of their solutions,
dispersions or emulsions to increase the adhesion of the compounds
of the formula (I) which have been sprayed on. Preference is given
here to using reactive organic polymers whose crosslinking products
form porous structures or reactive inorganic materials such as
metalate esters.
[0074] These above-described methods of applying the compounds of
the formula (I) to the support material can also be employed if the
compounds of the formula (I) are to be applied to the internal
walls of reactors.
[0075] Apart from spraying-on a suspension comprising compounds of
the formula (I), the powder of these compounds can be applied
directly to the shaped body using a method similar to a high-solids
coating process, as described in DE 4 442 346. In this process, the
shaped bodies are generally sprayed with an adhesion-promoting
liquid in parallel with the supply of powder. As in the case of
spraying, materials which act as binder and ensure increased
adhesion of the active components to the shaped body can be added
to the adhesion-promoting liquid.
[0076] Here too, it is possible to add reactive, i.e. crosslinking,
in-organic or organic components.
[0077] A further method of applying the compounds of the formula
(I) to the shaped body is to synthesize the compound or its
precursor directly on the shaped body. For this purpose, the
various solutions comprising the starting materials are brought
into contact with the shaped body either simultaneously or at brief
intervals. The shaped body can be brought into contact with the
solutions by spraying, dipping, steeping, impregnation or similar
procedures. The mixing of the liquids on the shaped body can result
in precipitation of the active component or its precursor on the
shaped body.
[0078] It is likewise possible to apply the desired metal ions by
successive steeping or impregnation.
[0079] The shaped bodies obtained in this way can, if necessary, be
subjected to a hydrothermal crystallization.
[0080] The shaped bodies obtained in this way can also be subjected
to a heat treatment step should this be necessary to generate the
compounds of the formula (I).
[0081] Here too, adhesion-promoting materials can be added before
or after the heat treatment step.
[0082] In the above-described processes for producing the catalysts
of the present invention, the compounds of the formula (I) are
applied to inert shaped bodies. However, it is also possible to
produce molded compounds of the formula (I) by producing
unsupported catalysts from the powders. This can be achieved by
tabletting or extrusion. A choice will be made between application
to inert shaped bodies as supports or molding to produce
unsupported catalysts on the basis of the production costs for the
compounds of the formula (I). When tabletting the oxidic compounds
of the formula (I), it is generally necessary to add lubricants.
These can be graphite, boron nitride or organic molecules such as
stearates or alginates. Tabletting can also be followed by a heat
treatment step in order to burn out the organic tabletting
aids.
[0083] In the case of extrusion, the active composition powders can
first be processed with a make-up liquid in a kneader, pan mill or
similar apparatus to produce a plastic composition. In this
compounding step, the composition being produced can be admixed
with further ingredients which either improve the properties of the
plastic composition in the actual shaping step or give the shaped
body produced from this composition better cohesion. For the
expert, there are a great number of possibilities for making use of
various additives. The amounts of additives present are not
critical: they should be high enough to be fully effective but not
so high that the catalytic activity of the compounds of the formula
(I) is reduced.
[0084] The shaped bodies obtained in this way can subsequently be
converted into granules which can then also be used in a suspension
process. The granules used then have particle sizes of from 100
.mu.m to 2 mm, preferably from 250 .mu.m to 1 mm.
[0085] A further possibility for producing the catalysts is to
embed compounds of the formula (I) in a solid matrix. The solid
matrix can be of an inorganic or organic nature.
[0086] To embed the compounds of the formula (I) in an inorganic
matrix, the compounds of the formula (I) can be suspended in
metalate esters or alkoxymetalates. Addition of bases or acids
results in polymerization of the metalate esters to give solid
materials. Preference is given here to the esters of silicic,
aluminic, titanic and/or zirconic acids.
[0087] As organic components, it is possible to use all materials
or material mixtures in which the compounds of the formula (I) can
be suspended and which can be polymerized in any way to form
solids.
[0088] The polymerization should be carried out in such a way that
the solid particles formed can be used in a fixed-bed arrangement.
Furthermore; the solid particles obtained should have sufficient
porosity for the starting materials and products to be able to be
transported to and from the active composition. To improve the
porosity, it is possible to add, during the polymerization,
auxiliaries which can be removed again by physical or chemical
treatments after the polymerization. The polymerization can also be
carried out in such a way as to produce an open-pored foam in which
the active composition is fixed.
[0089] The catalysts for step b) are, in particular, multimetal
cyanide catalysts of the formula
M.sup.1.sub.a[M.sup.2(CN).sub.b(A)c].sub.d.fM.sup.1.sub.gXn.h(H.sub.2O).eL-
,
[0090] where p1 M.sup.1 is at least one metal ion selected from the
group consisting of Zn2+, Fe2+, Co3+, Ni2+, Mn2+, Co2+, Sn2+, Pb2+,
Fe3+, Mo430 , Mo6+, Al3+, V4+, V5+, Sr2+, W4+, W6+, Cr2+, Cr3+,
Cd2+, preferably consisting of Zn2+, Fe2+, Ni2+, Mn2+, Co2+ and
Cr2+, particularly preferably Zn2+,
[0091] M.sup.2 is at least one metal ion selected from the group
consisting of Fe2+, Fe3+, Co3+, Cr3+, Mn2+, Mn3+, Rh3+, Ru2+, Ru3+,
V4+, V5+, Co2+, Ir3+ and Cr2+, preferably consisting of Co3+, Fe3+,
Fe2+, Rh3+, Ir3+, particularly preferably Co3+, Rh3+, Ir3+ and
Fe3+, identical to or different from M.sup.1,
[0092] A is at least one anion selected from the group consisting
of halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate,
isocyanate, cyanate, carboxylate, oxalate and nitrate,
[0093] X is at least one anion selected from the group consisting
of halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate,
isocyanate, cyanate, carboxylate, oxalate and nitrate,
[0094] L is at least one water-miscible organic ligand selected
from the group consistin of alcohols, aldehydes, ketones, ethers,
polyethers, esters, ureas, amides, nitrites and sulfides,
[0095] a, b, c, d, g and n are selected such that the compound is
electrically neutral,
[0096] e is the coordination number of the ligand,
[0097] e and f are fractional numbers or integers greater than or
equal to zero,
[0098] h is a fractional number or integer greater than or equal to
zero.
[0099] These can again be used in powder form, paste form or in the
form of relatively coarse granules for a suspension process. For
the fixed-bed method, the double metal cyanides can, according to
the present invention, be applied to solid supports, incorporated
into the latter or molded to form shaped bodies.
[0100] The methods suitable for this have already been described in
detail above.
[0101] The double metal cyanide complex can be prepared by
customary methods. Such methods are described, for example, in U.S.
Pat. No. 5,741,428, U.S. Pat. No. 5,693,584, U.S. Pat. No.
5,637,673, U.S. Pat. No. 5,627,122, U.S. Pat. No. 5,627,120, U.S.
Pat. No. 5,589,431, U.S. Pat. No. 5,536,883, U.S. Pat. No.
5,482,908, U.S. Pat. No. 5,470,813.
[0102] The preparation of the polyethers is usually divided into
the following process steps:
[0103] In process step a), lower alkylene oxides, in particular
ethylene oxide and/or propylene oxide, are added onto H-functional
initiator substances. H-functional initiator substances used in the
process of the present invention are preferably alcohols, in
particular those having from 1 to 8, but preferably 2 or 3,
hydroxyl groups and from 2 to 6 carbon atoms in the molecule.
[0104] Examples are glycols, in particular ethylene glycol and
propylene glycol, and also glycerol, trimethylolpropane or
pentaerythritol. It is also possible to use mixtures of alcohols
with one another or with water. The addition of the alkylene oxides
onto the initiator substances is carried out under the conditions
customary for this purpose, i.e. at temperatures in the range from
80 to 150.degree. C. and pressures in the range from 0.1 to 8
bar.
[0105] Before the alkylene oxides are metered in, the reaction
mixture should be made inert by stripping with an inert gas,
preferably nitrogen. The catalyst of the formula (I) can here be
present as a fixed bed or a moving bed or be suspended in the
initiator substance.
[0106] The commencement of the reaction can be recognized by a
decrease in the pressure in the reactor.
[0107] After the alkylene oxide has reacted and, if appropriate, a
further after-reaction time, the alkylene oxide reaction product is
separated from the catalyst and worked up. To eliminate fine
catalyst constituents and abraded material, the alkylene oxide
reaction product can be filtered. To remove volatile constituents,
the product is, as is customary, subjected to a distillation,
preferably under reduced pressure.
[0108] The product of process step a) preferably has a molecular
weight of from 100 to 1000 g/mol.
[0109] To carry out process step b), the final product of process
step a) is admixed with a multimetal catalyst of the formula (II)
and reacted with an alkylene oxide, in particular propylene oxide.
The multimetal catalyst can likewise be applied to inert supports
or be incorporated into the latter or molded to form shaped bodies,
but it can also be present as a suspension in the reaction mixture.
The reaction proceeds under the same reaction conditions as in
process step a). The end product of process step b) has a molar
mass of from 100 to 100,000, in particular from 1000 to 50,000.
[0110] The process step b) can be followed by a further process
step a), in particular one using ethylene oxide as alkylene oxide.
However, the molecular addition of an ethylene oxide end block can
also be carried out using customary alkaline catalysts such as
potassium hydroxide.
[0111] The polyetherols prepared by the process of the present
invention have a low content of unsaturated compounds, even at high
molar masses. The reaction proceeds in a very high space-time
yield.
[0112] The polyetherols prepared by the process of the present
invention are used, in particular, for producing polyurethanes.
[0113] The invention is illustrated by the following examples.
[0114] Production of Catalysts for Process Step a)
EXAMPLE 1
[0115] 600 g of hydrotalcite (C300, Giulini) were compounded with
400 g of boehmite (Pural.RTM. SB, Condea) and 610 ml of an aqueous
formic acid solution (2% by weight of formic acid) for one hour in
a kneader and extruded to produce round extrudates having a
diameter of 2 mm. The extrudates were dried at 120.degree. C. and
calcined at 500.degree. C. for 5 hours. Part of the extrudates
obtained was converted into 1.6 mm granules for Example 6.
EXAMPLE 2
[0116] A solution of 175 g of sodium carbonate and 398 g of sodium
hydroxide in 2 l of water was placed in a glass beaker and heated
to 40.degree. C. While stirring continually, a solution of 109 g of
lithium nitrate and 1238 g of aluminum nitrate in 1.5 l of water
was added over a period of 30 minutes. The resulting suspension was
then stirred for a further 2 hours at 40.degree. C. The solid
formed was then filtered off with suction, washed with water and
dried at 110.degree. C. for 16 hours.
EXAMPLE 3
[0117] 120 g of powder from Example 2 were compounded with 80 g of
boehmite (Pural.RTM. SB, Condea) and 59 ml of an aqueous formic
acid solution (2% by weight of formic acid) for one hour in a
kneader and extruded to produce round extrudates having a diameter
of 2 mm. The extrudates were dried at 120.degree. C. and calcined
at 500.degree. C. for 5 hours.
EXAMPLE 4
[0118] 200 g of powder from Example 2 were compounded with 52 ml of
an aqueous formic acid solution (2% by weight of formic acid) for
one hour in a kneader and extruded to produce round extrudates
having a diameter of 2 mm. The extrudates were dried at 120.degree.
C. cl EXAMPLE 5
[0119] 50 g of magnesium hydroxide carbonate (4
MgCO.sub.3.Mg(OH).sub.2) were compounded with 33.3 g of boehmite
(Pural.RTM. SB, Condea) and 78 ml of an aqueous formic acid
solution (2% by weight of formic acid) for one hour in a kneader
and extruded to produce round extrudates having a diameter of 2 mm.
The extrudates were dried at 120.degree. C. and calcined at
500.degree. C. for 5 hours.
EXAMPLE 6
[0120] The synthesis was carried out in a cleaned and dried 5 l
stirred reactor. At room temperature, 779.5 g of glycerol and 35.3
g of granulated catalyst as described in Example 1 were placed in
the reactor. The contents of the reactor were then made inert by
evacuating the reactor three times and filling it with nitrogen
after each evacuation. At 95.degree. C., a vacuum better than 1
mbar abs. was applied for 5 hours. Subsequently, a total of 1648 g
of propylene oxide was added a little at a time at 125.degree. C.
at such a rate that an internal reactor pressure of 7.2 bar abs.
was not exceeded. After the addition and reaction were complete, a
water pump vacuum was applied for 30 minutes at 125.degree. C. To
separate off the catalyst, the reaction product was filtered
through a double layer of a Seitz deep-bed filter. Analyses: OH
number=588 mg KOH/g, viscosity=788 mPa*s_(at 25.degree. C.),
unsaturated constituents=0.0226 meq/g, GPC: M.sub.n=198.3 g/mol,
M.sub.w=208.9 g/mol, D=1.053.
EXAMPLE 7
[0121] The synthesis was carried out in a cleaned and dried 5 l
stirred reactor. At 50.degree. C., 303.2 g of the product from
Example 6 were introduced. The contents of the reactor were made
inert by evacuating three times and subsequently filling with
nitrogen each time. Degassing was carried out by evacuation at less
than 1 mbar abs. for 1.5 hours at 105.degree. C. 1.589 g of a
multimetal catalyst from the reaction of zinc acetate with
hexacyanocobaltic acid were then added. The reactor was again
evacuated three times and filled with nitrogen each time. This was
followed by evacuation at less than 1 mbar abs. for 25 minutes at
125.degree. C. At the same temperature, a nitrogen prepressure of
3.5 bar was applied and 195 g of propylene oxide and 29 g of
ethylene oxide were added. The commencement of the reaction was
recognized by the pressure drop. Subsequently, a mixture of 3996 g
of propylene oxide and 570.5 g of ethylene oxide was metered in
over a period of 3.3 hours. After a further 30 minutes at
125.degree. C., the crude polyol was freed of volatile constituents
under reduced pressure. The catalyst was separated off by
filtration through a double layer of a Seitz deep-bed filter.
Analyses: OH number=35.8 mg KOH/g, viscosity=1024 mPa*s (at
25.degree. C.), unsaturated constituents=0.0028 meq/g, GPC:
M.sub.n=3525 g/mol, M.sub.w=3673 g/mol, D=1.042.
* * * * *