U.S. patent application number 14/438905 was filed with the patent office on 2015-10-22 for method for producing polyether carbonate polyols.
This patent application is currently assigned to BAYER MATERIALSCIENCE AG. The applicant listed for this patent is BAYER MATERIALSCIENCE AG. Invention is credited to Norbert HAHN, Joerg HOFMANN.
Application Number | 20150299374 14/438905 |
Document ID | / |
Family ID | 49552358 |
Filed Date | 2015-10-22 |
United States Patent
Application |
20150299374 |
Kind Code |
A1 |
HOFMANN; Joerg ; et
al. |
October 22, 2015 |
METHOD FOR PRODUCING POLYETHER CARBONATE POLYOLS
Abstract
The present invention relates to a method for producing
polyether carbonate polyols, wherein: (i) in a first step, (a)
carbon dioxide and propylene oxide or (b) carbon dioxide and a
mixture of propylene oxide and at least one further alkylene oxide
in a ratio by weight of >90:10 are attached to one or more
H-functional starting substances in the presence of at least one
DMC catalyst; ii) in a second step, the reaction mixture obtained
from step (i) is (ii-1) first chain-lengthened with a mixture
containing propylene oxide (PO) and ethylene oxide (EO) in a PO/EO
ratio by weight of 90/10 to 20/80 in the presence of at least one
DMC catalyst.
Inventors: |
HOFMANN; Joerg; (Krefeld,
DE) ; HAHN; Norbert; (Rommerskirchen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BAYER MATERIALSCIENCE AG |
Leverkusen |
|
DE |
|
|
Assignee: |
BAYER MATERIALSCIENCE AG
Leverkusen
DE
|
Family ID: |
49552358 |
Appl. No.: |
14/438905 |
Filed: |
November 6, 2013 |
PCT Filed: |
November 6, 2013 |
PCT NO: |
PCT/EP2013/073157 |
371 Date: |
April 28, 2015 |
Current U.S.
Class: |
521/172 ;
558/266 |
Current CPC
Class: |
C08G 2101/0083 20130101;
C08G 65/2696 20130101; C08G 18/48 20130101; C08G 18/1825 20130101;
C08G 2101/005 20130101; C08G 18/4816 20130101; C08G 65/2606
20130101; C08G 65/2663 20130101; C08G 2101/0058 20130101; C08G
18/4018 20130101; C08G 18/7657 20130101; C08G 2101/0008 20130101;
C08G 64/34 20130101; C08G 18/7621 20130101; C08G 65/331 20130101;
C08G 18/44 20130101; C08G 18/2063 20130101; C08G 65/2603 20130101;
C08G 18/14 20130101; C08G 18/7671 20130101; C08G 18/1833 20130101;
C08G 64/0208 20130101 |
International
Class: |
C08G 18/48 20060101
C08G018/48; C08G 18/08 20060101 C08G018/08; C08G 18/76 20060101
C08G018/76; C08G 65/26 20060101 C08G065/26 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 9, 2012 |
EP |
12192107.6 |
Jun 27, 2013 |
EP |
13174117.5 |
Claims
1. A process for preparing polyether carbonate polyol, comprising
(i) adding (a) carbon dioxide and propylene oxide or (b) carbon
dioxide and a mixture of propylene oxide and at least one further
alkylene oxide in a weight ratio of >90:10 onto one or more
H-functional starter substance(s) in the presence of at least one
DMC catalyst, (ii) a reaction mixture obtained from (i) (ii-1) is
first chain-extended with a mixture comprising propylene oxide (PO)
and ethylene oxide (EO) in a PO/EO weight ratio of 90/10 to 20/80
in the presence of at least one DMC catalyst, (ii-2) then a
resulting mixture is chain-extended with a mixture comprising
propylene oxide (PO) and ethylene oxide (EO) in a PO/EO weight
ratio of 60/40 to 2/98 in the presence of at least one DMC
catalyst, and (iii) polyether carbonate polyol resulting from (ii)
is chain-extended with ethylene oxide or a mixture of propylene
oxide (PO) and ethylene oxide (EO) in a PO/EO weight ratio of 5/95
to 0.1/99.9 in the presence of at least one DMC catalyst, where the
proportion by weight of EO in a mixture comprising PO and EO in
(ii-2) is higher than the proportion by weight of EO in mixture
comprising PO and EO in (ii-1).
2. The process as claimed in claim 1, wherein, in (i), (.alpha.) a
H-functional starter substance or a mixture of at least two
H-functional starter substances and/or a suspension medium is
initially charged and any water and/or other volatile compounds are
removed by elevated temperature and/or reduced pressure comprising
drying, with addition of the DMC catalyst to the H-functional
starter substance and/or to the mixture of at least two
H-functional starter substances and/or the suspension medium before
or after the drying, (.beta.) activation is accomplished by adding
a portion (based on the total amount of the amount of alkylene
oxides used in the activation and copolymerization) of alkylene
oxide selected from the group consisting of (a) propylene oxide and
(b) a mixture of propylene oxide and at least one further alkylene
oxide in a weight ratio of >90:10 to a mixture resulting from
(.alpha.), wherein said adding a portion of alkylene oxide can be
effected in optional presence of CO.sub.2, in which case a
temperature peak comprising a hotspot which occurs because of an
exothermic chemical reaction that follows and/or a pressure drop in
the reactor can occur, and where (.beta.) for activation can also
be effected repeatedly, (.gamma.) adding propylene oxide or a
mixture of propylene oxide and at least one further alkylene oxide
in a weight ratio of >90:10, carbon dioxide and optionally one
or more H-functional starter substance(s) to a mixture resulting
from (.beta.), where the one or more alkylene oxides used in
(.gamma.) may be the same as or different than the one or more
alkylene oxides used in (.beta.), where at least one H-functional
starter substance is added in at least one of steps (.alpha.) and
(.gamma.).
3. The process as claimed in claim 1, wherein one or more
H-functional starter substances used in (i) are one or more
compounds selected from the group consisting of ethylene glycol,
propylene glycol, propane-1,3-diol, butane-1,3-diol,
butane-1,4-diol, pentane-1,5-diol, 2-methylpropane-1,3-diol,
neopentyl glycol, hexane-1,6-diol, octane-1,8-diol, diethylene
glycol, dipropylene glycol, glycerol, trimethylolpropane,
pentaerythritol, sorbitol and polyether polyols having a molecular
weight Mn in a range from 150 to 4500 g/mol and a functionality of
2 to 3.
4. The process as claimed in claim 1, wherein a reaction mixture
obtained from (i) (ii-1) is first chain-extended with a mixture
comprising propylene oxide (PO) and ethylene oxide (EO) in a PO/EO
weight ratio of 80/20 to 30/70 in the presence of at least one DMC
catalyst, and (ii-2) then a resulting mixture is chain-extended
with a mixture comprising propylene oxide (PO) and ethylene oxide
(EO) in a PO/EO weight ratio of 40/60 to 5/95 in the presence of at
least one DMC catalyst.
5. The process as claimed in claim 1, wherein a suspension media is
used and comprises 4-methyl-2-oxo-1,3-dioxolane,
1,3-dioxolan-2-one, toluene, xylene, ethylbenzene, chlorobenzene,
dichlorobenzene and/or a mixture thereof.
6. The process as claimed in claim 1, wherein (ii-1) and/or (ii-2)
are repeated two to ten times.
7. The process as claimed in claim 6, wherein the proportion by
weight of EO increases on each repetition of (ii-1) and/or
(ii-2).
8. The process as claimed in claim 1, wherein the proportion by
weight of EO in the mixture of PO and EO is increased continuously
between a starting PO/EO mixing ratio and a final PO/EO mixing
ratio, the starting PO/EO mixing ratio corresponding to a PO/EO
weight ratio from the weight ratio defined for (ii-1), and the
final PO/EO mixing ratio corresponding to a PO/EO weight ratio from
the weight ratio defined for (ii-2).
9. The process as claimed in claim 1, wherein a mean length of
mixed blocks of PO and EO prepared in (ii-1) or (ii-2) is 1.0 to
20.0 alkylene oxide units, based in each case on one OH group of
the polyether carbonate polyol.
10. The process as claimed in claim 1, wherein (ii) is performed by
adding a solvent not containing any H-functional groups to a
reaction mixture obtained from (i).
11. The process as claimed in claim 1, wherein a mean length of an
alkylene oxide block prepared in (iii) is 1 to 30 alkylene oxide
units, based in each case on one OH group of the polyether
carbonate polyol.
12. A polyether carbonate polyol obtainable according to claim
1.
13. A process for producing one or more flexible polyurethane
foams, comprising using a polyol component A comprising a polyether
carbonate polyol obtainable according to claim 1.
14. A process for producing one or more flexible polyurethane foams
having an apparent density to DIN EN ISO 3386-1-98 in a range from
.gtoreq.10 kg/m.sup.3 to .ltoreq.150 kg/m.sup.3 and an indentation
hardness to DIN EN ISO 3386-1-98 in a range from .gtoreq.0.5 kPa to
.ltoreq.20 kPa (at 40% deformation and 4th cycle) comprising
reacting component A comprising A1 100 to 10 parts by weight (based
on the sum total of the parts by weight of components A1 and A2) of
polyether carbonate polyol obtainable according to claim 1, A2 0 to
90 parts by weight (based on the sum total of the parts by weight
of components A1 and A2) of conventional polyether polyol, A3 0.5
to 25 parts by weight (based on the sum total of the parts by
weight of components A1 and A2) of water and/or physical blowing
agents, A4 0.05 to 10 parts by weight (based on the sum total of
the parts by weight of components A1 and A2) of one or more
auxiliaries and additives optionally comprising one or more d)
catalysts, e) surface-active additives, f) pigments or flame
retardants, A5 0 to 10 parts by weight (based on the sum total of
the parts by weight of components A1 and A2) of one or more
compounds having one or more hydrogen atoms reactive toward
isocyanates and having a molecular weight of 62-399, with component
B comprising one or more polyisocyanates, where the process is
effected at an index of 50 to 250, and where parts by weight of
components A1 to A5 are normalized such that the sum total of the
parts by weight of components A1+A2 in said component A adds up to
100.
15. A flexible polyurethane foam having an apparent density to DIN
EN ISO 3386-1-98 in a range from .gtoreq.10 kg/m.sup.3 to
.ltoreq.150 kg/m.sup.3 and an indentation hardness to DIN EN ISO
3386-1-98 in a range from .gtoreq.0.5 kPa to .ltoreq.20 kPa (at 40%
deformation and 4th cycle) obtainable by a process as claimed in
claim 13.
Description
[0001] The present invention relates to a process for preparing
polyether carbonate polyols, to the polyether carbonate polyols
obtainable by this process and to the processing thereof for
production of flexible polyurethane foams.
[0002] The preparation of polyether carbonate polyols by catalytic
reaction of alkylene oxides (epoxides) and carbon dioxide in the
presence of H-functional starter substances ("starters") has been
the subject of intensive study for more than 40 years (e.g. Inoue
et al., Copolymerization of Carbon Dioxide and Epoxide with
Organometallic Compounds; Die Makromolekulare Chemie 130, 210-220,
1969). This reaction is shown in schematic form in scheme (I),
where R is an organic radical such as alkyl, alkylaryl or aryl,
each of which may also contain heteroatoms, for example O, S, Si,
etc., and where e, f and g are each integers, and where the product
shown here in scheme (I) for the polyether carbonate polyol should
merely be understood in such a way that blocks having the structure
shown may in principle be present in the polyether carbonate polyol
obtained, but the sequence, number and length of the blocks and the
OH functionality of the starter may vary, and it is not restricted
to the polyether carbonate polyol shown in scheme (I). This
reaction (see scheme (I)) is environmentally very advantageous,
since this reaction constitutes the conversion of a greenhouse gas
such as CO.sub.2 to a polymer. A further product, actually a
by-product, formed here is the cyclic carbonate shown in scheme (I)
(for example, when R=CH.sub.3, propylene carbonate).
##STR00001##
[0003] WO-A 2004/111107 discloses a process for preparing polyether
polyols having terminal ethylene oxide chains with DMC catalysis,
in which catalyst activation with propylene oxide is followed by
metered addition of a mixture of propylene oxide and ethylene oxide
with a constantly rising proportion of ethylene oxide ("ramping"),
then depletion of the residual monomer and finally addition of pure
ethylene oxide.
[0004] WO-A 2001/044347 discloses a process for DMC-catalyzed
preparation of polyether polyols, in which at least two different
epoxides are metered in together, with alteration of the ratio of
the epoxides to one another in the mixture during the common
metered addition.
[0005] WO-A 2008/058913 discloses a process for producing flexible
polyurethane foams using polyether carbonate polyols prepared by
means of DMC catalysis, wherein the polyether carbonate polyols
preferably have a block of pure alkylene oxide units, especially
pure propylene oxide units, at the chain end.
[0006] European patent application No. 11168433.8 discloses a
process for DMC-catalyzed preparation of polyether carbonate
polyols having a mixed block composed of at least two different
alkylene oxides in a molar ratio of 15/85 to 60/40, and flexible
polyurethane foams obtainable therefrom.
[0007] The polyether carbonate polyols known from the prior art
have the disadvantage that, in the event of a (partial) exchange of
a polyether polyol for a polyether carbonate polyol in a polyol
formulation, the further constituents of the polyol formulation
(additives) have to be adjusted in terms of type and/or amount for
the processing to give flexible polyurethane foams, in order to
achieve impeccable processibility. This is observed especially in
the case of processing of the polyether carbonate polyols to give
flexible polyurethane foams of the cold foam type (also referred to
as high resilience or HR foam). However, it is desirable to be able
to replace the polyether polyol at least partly with a polyether
carbonate polyol while retaining the good processibility without
having to adjust the further constituents of the polyol formulation
(additives) in terms of type and/or amount.
[0008] It was therefore an object of the present invention to
provide a process for producing polyether carbonate polyols having
a minimum polydispersity and good processibility to give flexible
polyurethane foams, especially to give flexible polyurethane foams
of the cold foam type.
[0009] It has been found that, surprisingly, the object of the
invention is achieved by a process for preparing polyether
carbonate polyols, characterized in that [0010] (i) in a first step
[0011] (a) carbon dioxide and propylene oxide or [0012] (b) carbon
dioxide and a mixture of propylene oxide and at least one further
alkylene oxide in a weight ratio of >90:10, preferably 91:9 to
99.9:0.1, are added onto one or more H-functional starter
substance(s) in the presence of at least one DMC catalyst, [0013]
(ii) in a second step the reaction mixture obtained from step (i)
[0014] (ii-1) is first chain-extended with a mixture comprising
propylene oxide (PO) and ethylene oxide (EO) in a PO/EO weight
ratio of 90/10 to 20/80, preferably of 80/20 to 30/70, more
preferably of 75/25 to 35/65, in the presence of at least one DMC
catalyst, where it is also possible to effect step (ii-1)
repeatedly with different PO/EO weight ratios in each case, [0015]
(ii-2) then the resulting mixture is chain-extended with a mixture
comprising propylene oxide (PO) and ethylene oxide (EO) in a PO/EO
weight ratio of 60/40 to 2/98, preferably of 40/60 to 5/95, more
preferably of 30/70 to 10/90, in the presence of at least one DMC
catalyst, where it is also possible to effect step (ii-2)
repeatedly with different PO/EO weight ratios in each case, and
[0016] (iii) the polyether carbonate polyol resulting from step
(ii) is chain-extended with ethylene oxide or a mixture of
propylene oxide (PO) and ethylene oxide (EO) in a PO/EO weight
ratio of 5/95 to 0.1/99.9, preferably ethylene oxide, in the
presence of at least one DMC catalyst, where the proportion by
weight of EO in the mixture comprising PO and EO in step (ii-2) is
higher than the proportion by weight of EO in the mixture
comprising PO and EO in step (ii-1).
[0017] The present invention further provides a process for
producing flexible polyurethane foams, wherein the starting
material used is a polyol component (component A) comprising a
polyether carbonate polyol obtainable by a process, characterized
in that [0018] (i) in a first step [0019] (a) carbon dioxide and
propylene oxide or [0020] (b) carbon dioxide and a mixture of
propylene oxide and at least one further alkylene oxide in a weight
ratio of >90:10, preferably 91:9 to 99.9:0.1, are added onto one
or more H-functional starter substance(s) in the presence of at
least one DMC catalyst, [0021] (ii) in a second step the reaction
mixture obtained from step (i) [0022] (ii-1) is first
chain-extended with a mixture comprising propylene oxide (PO) and
ethylene oxide (EO) in a PO/EO weight ratio of 90/10 to 20/80,
preferably of 80/20 to 30/70, more preferably of 75/25 to 35/65, in
the presence of at least one DMC catalyst, where it is also
possible to effect step (ii-1) repeatedly with different PO/EO
weight ratios in each case, [0023] (ii-2) then the resulting
mixture is chain-extended with a mixture comprising propylene oxide
(PO) and ethylene oxide (EO) in a PO/EO weight ratio of 60/40 to
2/98, preferably of 40/60 to 5/95, more preferably of 30/70 to
10/90, in the presence of at least one DMC catalyst, where it is
also possible to effect step (ii-2) repeatedly with different PO/EO
weight ratios in each case, [0024] (iii) the polyether carbonate
polyol resulting from step (ii) is chain-extended with ethylene
oxide or a mixture of propylene oxide (PO) and ethylene oxide (EO)
in a PO/EO weight ratio of 5/95 to 0.1/99.9, preferably ethylene
oxide, in the presence of at least one DMC catalyst, where the
proportion by weight of EO in the mixture comprising PO and EO in
step (ii-2) is higher than the proportion by weight of EO in the
mixture comprising PO and EO in step (ii-1).
[0025] The inventive flexible polyurethane foams preferably have an
apparent density to DIN EN ISO 3386-1-98 in the range from
.gtoreq.10 kg/m.sup.3 to .ltoreq.150 kg/m.sup.3, preferably of
.gtoreq.20 kg/m.sup.3 to .ltoreq.70 kg/m.sup.3, and the indentation
hardness thereof to DIN EN ISO 3386-1-98 is preferably in the range
from .gtoreq.0.5 kPa to .ltoreq.20 kPa (at 40% deformation and 4th
cycle).
Step (i):
[0026] The addition of the one or more alkylene oxides and carbon
dioxide in the presence of at least one DMC catalyst onto one or
more H-functional starter substance(s) ("copolymerization") leads
to a reaction mixture comprising the polyether carbonate polyol and
possibly cyclic carbonate (cf. scheme (I); for example, in the case
of addition of propylene oxide (R=CH.sub.3), the result is thus
propylene carbonate).
[0027] For example, the process in step (i) is characterized in
that [0028] (.alpha.) the H-functional starter substance or a
mixture of at least two H-functional starter substances or a
suspension medium is initially charged and any water and/or other
volatile compounds are removed by elevated temperature and/or
reduced pressure ("drying"), with addition of the DMC catalyst to
the H-functional starter substance or to the mixture of at least
two H-functional starter substances or the suspension medium before
or after the drying, [0029] (.beta.) activation is accomplished by
adding a portion (based on the total amount of the amount of
alkylene oxides used in the activation and copolymerization) of
alkylene oxide selected from the group consisting of [0030] (a)
propylene oxide and [0031] (b) a mixture of propylene oxide and at
least one further alkylene oxide in a weight ratio of >90:10,
preferably 91:9 to 99.9:0.1, [0032] to the mixture resulting from
step (a), it being possible for this addition of a portion of
alkylene oxide to be effected in the optional presence of CO.sub.2,
in which case the temperature peak ("hotspot") which occurs because
of the exothermic chemical reaction that follows and/or a pressure
drop in the reactor is awaited, and where step (.beta.) for
activation can also be effected repeatedly, [0033] (.gamma.)
propylene oxide or a mixture of propylene oxide and at least one
further alkylene oxide in a weight ratio of >90:10, preferably
91:9 to 99.9:0.1, carbon dioxide and optionally one or more
H-functional starter substance(s) are added to the mixture
resulting from step (.beta.), where the alkylene oxides used in
step (.gamma.) may be the same as or different than the alkylene
oxides used in step (.beta.), where at least one H-functional
starter substance is added in at least one of steps (.alpha.) and
(.gamma.).
[0034] Any suspension media used do not contain any H-functional
groups. Suitable suspension media are all polar aprotic, weakly
polar aprotic and nonpolar aprotic solvents, none of which contain
any H-functional groups. The suspension medium used may also be a
mixture of two or more of these suspension media. The following
polar aprotic suspension media are mentioned here by way of
example: 4-methyl-2-oxo-1,3-dioxolane (also referred to hereinafter
as cyclic propylene carbonate or cPC), 1,3-dioxolan-2-one (also
referred to hereinafter as cyclic ethylene carbonate or cEC),
acetone, methyl ethyl ketone, acetonitrile, nitromethane, dimethyl
sulfoxide, sulfolane, dimethylformamide, dimethylacetamide and
N-methylpyrrolidone. The group of the nonpolar and weakly polar
aprotic suspension media includes, for example, ethers, for example
dioxane, diethyl ether, methyl tert-butyl ether and
tetrahydrofuran, esters, for example ethyl acetate and butyl
acetate, hydrocarbons, for example pentane, n-hexane, benzene and
alkylated benzene derivatives (e.g. toluene, xylene, ethylbenzene)
and chlorinated hydrocarbons, for example chloroform,
chlorobenzene, dichlorobenzene and carbon tetrachloride. Preferred
suspension media are 4-methyl-2-oxo-1,3-dioxolane,
1,3-dioxolan-2-one, toluene, xylene, ethylbenzene, chlorobenzene
and dichlorobenzene, and mixtures of two or more of these
suspension media; particular preference is given to
4-methyl-2-oxo-1,3-dioxolane and 1,3-dioxolan-2-one or a mixture of
4-methyl-2-oxo-1,3-dioxolane and 1,3-dioxolan-2-one.
[0035] In general, for the process according to the invention, in
step (i), it is possible to use (a) propylene oxide or (b) a
mixture of propylene oxide and at least one further alkylene oxide
in a weight ratio of >90:10, preferably 91:9 to 99.9:0.1.
Alkylene oxides (epoxides) usable in the mixture with propylene
oxide are those having 2-24 carbon atoms. The alkylene oxides
having 2-24 carbon atoms are, for example, one or more compounds
selected from the group consisting of ethylene oxide, 1-butene
oxide, 2,3-butene oxide, 2-methyl-1,2-propene oxide (isobutene
oxide), 1-pentene oxide, 2,3-pentene oxide, 2-methyl-1,2-butene
oxide, 3-methyl-1,2-butene oxide, 1-hexene oxide, 2,3-hexene oxide,
3,4-hexene oxide, 2-methyl-1,2-pentene oxide, 4-methyl-1,2-pentene
oxide, 2-ethyl-1,2-butene oxide, 1-heptene oxide, 1-octene oxide,
1-nonene oxide, 1-decene oxide, 1-undecene oxide, 1-dodecene oxide,
4-methyl-1,2-pentene oxide, butadiene monoxide, isoprene monoxide,
cyclopentene oxide, cyclohexene oxide, cycloheptene oxide,
cyclooctene oxide, styrene oxide, methylstyrene oxide, pinene
oxide, mono- or polyepoxidized fats as mono-, di- and
triglycerides, epoxidized fatty acids, C.sub.1-C.sub.24 esters of
epoxidized fatty acids, epichlorohydrin, glycidol, and derivatives
of glycidol, for example methyl glycidyl ether, ethyl glycidyl
ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, glycidyl
methacrylate and epoxy-functional alkyloxysilanes, for example
3-glycidyloxypropyltrimethoxysilane,
3-glycidyloxypropyltriethoxysilane,
3-glycidyloxypropyltripropoxysilane,
3-glycidyloxypropylmethyldimethoxysilane,
3-glycidyloxypropylethyldiethoxysilane,
3-glycidyloxypropyltriisopropoxysilane. Preference is given to
using, in step (i), propylene oxide or a mixture of propylene oxide
and 1-butene oxide in a weight ratio of >90:10, more preferably
91:9 to 99.9:0.1; in particular, pure propylene oxide is used.
[0036] Suitable H-functional starter substances ("starters") used
may be compounds having hydrogen atoms active in respect of the
alkoxylation and having a molar mass of 18 to 4500 g/mol,
preferably of 60 to 500 g/mol and more preferably of 62 to 182
g/mol. The ability to use a starter having a low molar mass is a
distinct advantage over the use of oligomeric starters prepared by
means of a prior alkoxylation. More particularly, economic
viability is achieved, which is enabled by the omission of a
separate alkoxylation process.
[0037] Groups which have active hydrogen atoms and are active in
respect of the alkoxylation are, for example, --OH, --NH.sub.2
(primary amines), --NH-- (secondary amines), --SH and --CO.sub.2H,
preferably --OH and --NH.sub.2, especially preferably --OH.
H-Functional starter substances used are, for example, one or more
compounds selected from the group consisting of mono- and
polyhydric alcohols, polyfunctional amines, polyfunctional thiols,
amino alcohols, thio alcohols, hydroxy esters, polyether polyols,
polyester polyols, polyester ether polyols, polyether carbonate
polyols, polycarbonate polyols, polycarbonates, polyethyleneimines,
polyetheramines, polytetrahydrofurans (e.g. PolyTHF.RTM. from
BASF), polytetrahydrofuran amines, polyether thiols, polyacrylate
polyols, castor oil, the mono- or diglyceride of castor oil,
monoglycerides of fatty acids, chemically modified mono-, di-
and/or triglycerides of fatty acids, and C.sub.1-C.sub.24 alkyl
fatty acid esters containing an average of at least 2 OH groups per
molecule. By way of example the C.sub.1-C.sub.24-alkyl fatty acid
esters containing an average of at least 2 OH groups per molecule
are commercial products such as Lupranol Balance.RTM. (from BASF
AG), Merginol.RTM. products (from Hobum Oleochemicals GmbH),
Sovermol.RTM. products (from Cognis Deutschland GmbH & Co. KG)
and Soyol.RTM.TM products (from USSC Co.).
[0038] The mono-H-functional starter substances used may be
alcohols, amines, thiols and carboxylic acids. The monofunctional
alcohols used may be: methanol, ethanol, 1-propanol, 2-propanol,
1-butanol, 2-butanol, tert-butanol, 3-buten-1-ol, 3-butyn-1-ol,
2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol, propargyl alcohol,
2-methyl-2-propanol, 1-tert-butoxy-2-propanol, 1-pentanol,
2-pentanol, 3-pentanol, 1-hexanol, 2-hexanol, 3-hexanol,
1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol,
3-octanol, 4-octanol, phenol, 2-hydroxybiphenyl, 3-hydroxybiphenyl,
4-hydroxybiphenyl, 2-hydroxypyridine, 3-hydroxypyridine,
4-hydroxypyridine. Useful monofunctional amines include:
butylamine, tert-butylamine, pentylamine, hexylamine, aniline,
aziridine, pyrrolidine, piperidine, morpholine. The monofunctional
thiols used may be: ethanethiol, 1-propanethiol, 2-propanethiol,
1-butanethiol, 3-methyl-1-butanethiol, 2-butene-1-thiol,
thiophenol. Monofunctional carboxylic acids include: formic acid,
acetic acid, propionic acid, butyric acid, fatty acids such as
stearic acid, palmitic acid, oleic acid, linoleic acid, linolenic
acid, benzoic acid, acrylic acid.
[0039] Polyhydric alcohols suitable as H-functional starter
substances are, for example, dihydric alcohols (for example
ethylene glycol, diethylene glycol, propylene glycol, dipropylene
glycol, 1,3-propanediol, 1,4-butanediol, 1,4-butenediol,
1,4-butynediol, neopentyl glycol, 1,5-pentanediol,
methylpentanediols (for example 3-methyl-1,5-pentanediol),
1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol,
bis(hydroxymethyl)cyclohexanes (for example
1,4-bis(hydroxymethyl)cyclohexane), triethylene glycol,
tetraethylene glycol, polyethylene glycols, dipropylene glycol,
tripropylene glycol, polypropylene glycols, dibutylene glycol and
polybutylene glycols); trihydric alcohols (for example
trimethylolpropane, glycerol, trishydroxyethyl isocyanurate, castor
oil); tetrahydric alcohols (for example pentaerythritol);
polyalcohols (for example sorbitol, hexitol, sucrose, starch,
starch hydrolyzates, cellulose, cellulose hydrolyzates,
hydroxy-functionalized fats and oils, especially castor oil), and
all the modification products of these aforementioned alcohols with
different amounts of .epsilon.-caprolactone.
[0040] The H-functional starter substances may also be selected
from the substance class of the polyether polyols having a
molecular weight M.sub.n in the range from 18 to 4500 g/mol and a
functionality of 2 to 3. Preference is given to polyether polyols
formed from repeating ethylene oxide and propylene oxide units,
preferably having a proportion of 35 to 100% propylene oxide units,
more preferably having a proportion of 50 to 100% propylene oxide
units. These may be random copolymers, gradient copolymers,
alternating copolymers or block copolymers of ethylene oxide and
propylene oxide.
[0041] The H-functional starter substances may also be selected
from the substance class of the polyester polyols. The polyester
polyols used are at least difunctional polyesters. Preferably,
polyester polyols consist of alternating acid and alcohol units.
The acid components used are, for example, succinic acid, maleic
acid, maleic anhydride, adipic acid, phthalic anhydride, phthalic
acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid,
tetrahydrophthalic anhydride, hexahydrophthalic anhydride or
mixtures of the acids and/or anhydrides mentioned.
[0042] The alcohol components used are, for example, ethanediol,
1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol,
neopentyl glycol, 1,6-hexanediol,
1,4-bis(hydroxymethyl)cyclohexane, diethylene glycol, dipropylene
glycol, trimethylolpropane, glycerol, pentaerythritol or mixtures
of the alcohols mentioned. If the alcohol components used are
dihydric or polyhydric polyether polyols, the result is polyester
ether polyols which can likewise serve as starter substances for
preparation of the polyether carbonate polyols.
[0043] In addition, H-functional starter substances used may be
polycarbonate diols which are prepared, for example, by reaction of
phosgene, dimethyl carbonate, diethyl carbonate or diphenyl
carbonate and difunctional alcohols or polyester polyols or
polyether polyols. Examples of polycarbonates can be found, for
example, in EP-A 1359177.
[0044] In a further embodiment of the invention, it is possible to
use polyether carbonate polyols as H-functional starter substances.
More particularly, polyether carbonate polyols obtainable by the
process step (i) described here are used. For this purpose, these
polyether carbonate polyols used as H-functional starter substances
are prepared in a separate reaction step beforehand.
[0045] The H-functional starter substances generally have a
functionality (i.e. the number of hydrogen atoms active in respect
of the polymerization per molecule) of 1 to 8, preferably of 2 or
3. The H-functional starter substances are used either individually
or as a mixture of at least two H-functional starter
substances.
[0046] More preferably, the H-functional starter substances are one
or more compounds selected from the group consisting of ethylene
glycol, propylene glycol, propane-1,3-diol, butane-1,3-diol,
butane-1,4-diol, pentane-1,5-diol, 2-methylpropane-1,3-diol,
neopentyl glycol, hexane-1,6-diol, octane-1,8-diol, diethylene
glycol, dipropylene glycol, glycerol, trimethylolpropane,
pentaerythritol, sorbitol and polyether polyols having a molecular
weight Mn in the range from 150 to 4500 g/mol and a functionality
of 2 to 3.
[0047] The polyether carbonate polyols are prepared by catalytic
addition of carbon dioxide and alkylene oxides onto H-functional
starter substances. In the context of the invention, "H-functional"
is understood to mean the number of hydrogen atoms active in
respect of the alkoxylation per molecule of the starter
substance.
Step (.alpha.):
[0048] Preferably, in step (.alpha.), a suspension medium not
containing any H-functional groups is initially charged in the
reactor, optionally together with DMC catalyst, and no H-functional
starter substance is initially charged in the reactor at this time.
Alternatively, it is also possible in step (.alpha.) to initially
charge a suspension medium not containing any H-functional groups
and additionally a portion of the H-functional starter substance(s)
and optionally DMC catalyst in the reactor, or it is also possible
in step (.alpha.) to initially charge a portion of the H-functional
starter substance(s) and optionally DMC catalyst in the reactor. In
addition, it is also possible in step (.alpha.) to initially charge
the total amount of the H-functional starter substance(s) and
optionally DMC catalyst in the reactor.
[0049] The DMC catalyst is preferably used in such an amount that
the content of DMC catalyst in the reaction product that results
from step (i) is 10 to 10 000 ppm, especially preferably 20 to 5000
ppm and most preferably 50 to 500 ppm.
[0050] In a preferred embodiment, inert gas (for example argon or
nitrogen), an inert gas/carbon dioxide mixture or carbon dioxide is
introduced into the resulting mixture of DMC catalyst with
suspension medium and/or H-functional starter substance at a
temperature of 90 to 150.degree. C., more preferably of 100 to
140.degree. C., and at the same time a reduced pressure (absolute)
of 10 mbar to 800 mbar, more preferably of 50 mbar to 200 mbar, is
applied.
[0051] In an alternative preferred embodiment, the resulting
mixture of DMC catalyst with suspension medium and/or H-functional
starter substance at a temperature of 90 to 150.degree. C., more
preferably of 100 to 140.degree. C., is contacted at least once,
preferably three times, with 1.5 bar to 10 bar (absolute), more
preferably 3 bar to 6 bar (absolute), of an inert gas (for example
argon or nitrogen), an inert gas/carbon dioxide mixture or carbon
dioxide and then the gauge pressure is reduced in each case to
about 1 bar (absolute).
[0052] The DMC catalyst can be added, for example, in solid form or
as a suspension in a suspension medium or a plurality of suspension
media or as a suspension in one or more H-functional starter
substance(s).
[0053] In a further embodiment, in step (.alpha.), [0054]
(.alpha.-I) suspension medium and/or a portion or the total amount
of H-functional starter substance is initially charged and [0055]
(.alpha.-II) the temperature of the suspension medium and/or the
H-functional starter substance is brought to 50 to 200.degree. C.,
preferably 80 to 160.degree. C., more preferably 100 to 140.degree.
C., and/or the pressure in the reactor is lowered to less than 500
mbar, preferably 5 mbar to 100 mbar, in the course of which an
inert gas stream (for example of argon or nitrogen), an inert
gas/carbon dioxide stream or a carbon dioxide stream is optionally
passed through the reactor, where the double metal cyanide catalyst
is added to the suspension medium and/or to the H-functional
starter substance (.alpha.-I) or immediately thereafter in step
(.alpha.-II), and where the suspension medium does not contain any
H-functional groups.
Step (.beta.):
[0056] Step (.beta.) serves to activate the DMC catalyst. This step
can optionally be conducted under inert gas atmosphere, under an
atmosphere of inert gas/carbon dioxide mixture or under a carbon
dioxide atmosphere. In the context of this invention, activation
refers to a step in which a portion of alkylene oxide compound
selected from the group consisting of (a) propylene oxide and (b) a
mixture of propylene oxide and at least one further alkylene oxide
in a weight ratio of >90:10, preferably 91:9 to 99.9:0.1, is
added at temperatures of 90 to 150.degree. C. to the DMC catalyst
suspension, and then the addition of the alkylene oxide compound is
stopped, where evolution of heat which can lead to a temperature
peak ("hotspot") is observed because of an exothermic chemical
reaction which follows, as is a pressure drop in the reactor
because of the reaction of alkylene oxide and any CO2. The process
step of activation is the period from the addition of the portion
of alkylene oxide compound, optionally in the presence of CO2, to
the DMC catalyst until the occurrence of the evolution of heat.
Optionally, the portion of alkylene oxide compound can be added to
the DMC catalyst in a plurality of individual steps, optionally in
the presence of CO2, and then the addition of the alkylene oxide
compound can be stopped in each case. In this case, the process
step of activation comprises the period from the addition of the
first portion of alkylene oxide compound, optionally in the
presence of CO2, to the DMC catalyst until the occurrence of the
evolution of heat after addition of the last portion of alkylene
oxide compound. In general, the activation step may be preceded by
a step for drying the DMC catalyst and optionally the H-functional
starter substance at elevated temperature and/or reduced pressure,
optionally with passage of an inert gas through the reaction
mixture.
[0057] The one or more alkylene oxides (and optionally the carbon
dioxide) can in principle be metered in in different ways. The
commencement of the metered addition can be effected from vacuum or
at a previously chosen supply pressure. The supply pressure is
preferably established by introduction of an inert gas (for example
nitrogen or argon) or of carbon dioxide, where the pressure (in
absolute terms) is 5 mbar to 100 bar, preferably 10 mbar to 50 bar
and especially preferably 20 mbar to 50 bar.
[0058] In a preferred embodiment, the amount of one or more
alkylene oxides used in the activation in step (.beta.) is 0.1 to
25.0% by weight, preferably 1.0 to 20.0% by weight, especially
preferably 2.0 to 16.0% by weight (based on the amount of
suspension medium and/or H-functional starter substance used in
step (.alpha.)). The alkylene oxide can be added in one step or in
two or more portions. Preferably, after addition of a portion of
alkylene oxide compound, the addition of the alkylene oxide
compound is stopped until the occurrence of evolution of heat and
only then is the next portion of alkylene oxide compound added.
Preference is also given to a two-stage activation (step .beta.),
where [0059] (.beta.1) in a first activation stage a first portion
of alkylene oxide is added under inert gas atmosphere and [0060]
(.beta.2) in a second activation stage a second portion of alkylene
oxide is added under carbon dioxide atmosphere.
Step (.gamma.):
[0061] For the process according to the invention, it has been
found that step (.gamma.) is advantageously conducted at 50 to
150.degree. C., preferably at 60 to 145.degree. C., more preferably
at 70 to 140.degree. C. and most preferably at 90 to 130.degree. C.
Below 50.degree. C., the reaction to form a polyether carbonate
polyol proceeds only very gradually. At temperatures above
150.degree. C., the amount of unwanted by-products rises
significantly.
[0062] The metered addition of the alkylene oxides selected from
the group consisting of (a) propylene oxide and (b) a mixture of
propylene oxide and at least one further alkylene oxide in a weight
ratio of >90:10, preferably 91:9 to 99.9:0.1, and of the carbon
dioxide can be effected simultaneously, alternately or
sequentially, it being possible to add the total amount of carbon
dioxide all at once or by metered addition over the reaction time.
It is possible, during the addition of the alkylene oxide, to
increase or lower the CO.sub.2 pressure gradually or stepwise or to
leave it constant. Preferably, the total pressure is kept constant
during the reaction by metered addition of further carbon dioxide.
The metered addition of one or more alkylene oxides and/or the
CO.sub.2 is effected simultaneously, alternately or sequentially
with respect to the metered addition of carbon dioxide. It is
possible to meter in the alkylene oxide at a constant metering
rate, or to increase or lower the metering rate gradually or
stepwise, or to add the alkylene oxide in portions. Preferably, the
alkylene oxide is added to the reaction mixture at a constant
metering rate. If a plurality of alkylene oxides are used for
synthesis of the polyether carbonate polyols, the alkylene oxides
can be metered in individually or as a mixture. The metered
addition of the alkylene oxides can be effected simultaneously,
alternately or sequentially, each via separate metering points
(addition points), or via one or more metering points, in which
case the alkylene oxides can be metered in individually or as a
mixture. It is possible via the manner and/or sequence of the
metered addition of the alkylene oxides and/or the carbon dioxide
to synthesize random, alternating, block or gradient polyether
carbonate polyols.
[0063] Preferably, an excess of carbon dioxide is used, based on
the calculated amount of carbon dioxide incorporated in the
polyether carbonate polyol, since an excess of carbon dioxide is
advantageous because of the low reactivity of carbon dioxide. The
amount of carbon dioxide can be fixed via the total pressure under
the respective reaction conditions. An advantageous total pressure
(in absolute terms) for the copolymerization for preparation of the
polyether carbonate polyols has been found to be in the range from
0.01 to 120 bar, preferably 0.1 to 110 bar, more preferably from 1
to 100 bar. It is possible to feed in the carbon dioxide
continuously or discontinuously. This depends on how quickly the
alkylene oxides and the CO.sub.2 are consumed and whether the
product is supposed to contain any CO.sub.2-free polyether blocks
or blocks having different CO.sub.2 content. The amount of the
carbon dioxide (reported as pressure) can likewise vary in the
course of addition of the alkylene oxides. According to the
reaction conditions selected, it is possible to introduce the
CO.sub.2 into the reactor in the gaseous, liquid or supercritical
state. CO.sub.2 can also be added to the reactor in solid form and
then be converted under the selected reaction conditions to the
gaseous, dissolved, liquid and/or supercritical state.
[0064] In a process comprising metered addition of one or more
H-functional starter substance(s) in step (.gamma.), the metered
addition of one or more H-functional starter substance(s), one or
more alkylene oxide(s) and optionally also of the carbon dioxide
can be effected simultaneously or sequentially (in portions); for
example, it is possible to add the total amount of carbon dioxide,
the amount of H-functional starter substances and/or the amount of
alkylene oxides metered in in step (.gamma.) all at once or
continuously. The term "continuously" used here can be defined as a
mode of addition of a reactant such that a concentration of the
reactant effective for the copolymerization is maintained, meaning
that, for example, the metered addition can be effected with a
constant metering rate, with a varying metering rate or in
portions.
[0065] It is possible, during the addition of the alkylene oxide
and/or the H-functional starter substances, to increase or lower
the CO.sub.2 pressure gradually or stepwise or to leave it
constant. Preferably, the total pressure is kept constant during
the reaction by metered addition of further carbon dioxide. The
metered addition of one or more alkylene oxide(s) and/or the one or
more H-functional starter substance(s) is effected simultaneously
or sequentially with respect to the metered addition of carbon
dioxide. It is possible to meter in the alkylene oxide at a
constant metering rate, or to increase or lower the metering rate
gradually or stepwise, or to add the alkylene oxide in portions.
Preferably, the alkylene oxide is added to the reaction mixture at
a constant metering rate. If a plurality of alkylene oxides are
used for synthesis of the polyether carbonate polyols, the alkylene
oxides can be metered in individually or as a mixture. The metered
addition of the alkylene oxides and/or of the H-functional starter
substances can be effected simultaneously or sequentially, each via
separate metering points (addition points), or via one or more
metering points, in which case the alkylene oxides and/or the
H-functional starter substances can be metered in individually or
as a mixture. It is possible via the manner and/or sequence of the
metered addition of the H-functional starter substances, the
alkylene oxides and/or the carbon dioxide to synthesize random,
alternating, block or gradient polyether carbonate polyols.
[0066] In a preferred embodiment, in step (.gamma.), the metered
addition of the one or more H-functional starter substance(s) is
ended at a juncture prior to the addition of the alkylene
oxide.
[0067] Preferably, an excess of carbon dioxide is used, based on
the calculated amount of carbon dioxide incorporated in the
polyether carbonate polyol, since an excess of carbon dioxide is
advantageous because of the low reactivity of carbon dioxide. The
amount of carbon dioxide can be fixed via the total pressure under
the respective reaction conditions. An advantageous total pressure
(in absolute terms) for the copolymerization for preparation of the
polyether carbonate polyols has been found to be in the range from
0.01 to 120 bar, preferably 0.1 to 110 bar, more preferably from 1
to 100 bar. It is possible to feed in the carbon dioxide
continuously or discontinuously. This depends on how quickly the
alkylene oxides are consumed and whether the product is supposed to
contain any CO.sub.2-free polyether blocks. The amount of the
carbon dioxide (reported as pressure) can likewise vary in the
course of addition of the alkylene oxides. CO.sub.2 can also be
added to the reactor in solid form and then be converted under the
selected reaction conditions to the gaseous, dissolved, liquid
and/or supercritical state.
[0068] One characteristic feature of a preferred embodiment of the
process according to the invention is that, in step (.gamma.), the
total amount of the one or more H-functional starter substance(s)
is added, i.e. a suspension medium is used in step (.alpha.). This
addition can be effected at a constant metering rate, at a varying
metering rate or in portions.
[0069] Preferably, the polyether carbonate polyols are prepared in
a continuous process which comprises either a continuous
copolymerization or a continuous addition of the one or more
H-functional starter substance(s). The invention therefore also
provides a process wherein, in step (.gamma.), one or more
H-functional starter substance(s), one or more alkylene oxide(s)
and DMC catalyst are metered continuously into the reactor in the
presence of carbon dioxide ("copolymerization"), and wherein the
resulting reaction mixture (comprising the reaction product) is
removed continuously from the reactor. Preferably, in step
(.gamma.), the DMC catalyst which has been suspended in
H-functional starter substance is added continuously. The metered
addition of the alkylene oxide, the H-functional starter substance
and the DMC catalyst can be effected via separate or combined
metering points. In a preferred embodiment, the alkylene oxide and
the H-functional starter substance are metered continuously into
the reaction mixture via separate metering points. This addition of
the one or more H-functional starter substance(s) can be effected
as a continuous metered addition into the reactor or in
portions.
[0070] For example, for the continuous process for preparing the
polyether carbonate polyols in steps (.alpha.) and (.beta.), an
activated DMC catalyst/suspension medium mixture is prepared, then,
in step (.gamma.), [0071] (.gamma.1) a portion each of one or more
H-functional starter substance(s), one or more alkylene oxide(s)
and carbon dioxide are metered in to initiate the copolymerization,
and [0072] (.gamma.2) during the progress of the copolymerization,
the remaining amount of each of DMC catalyst, one or more starter
substance(s) and alkylene oxide(s) is metered in continuously, with
simultaneous removal of resulting reaction mixture continuously
from the reactor.
[0073] In step (.gamma.), the DMC catalyst is preferably added
suspended in the H-functional starter substance.
[0074] Steps (.alpha.), (.beta.) and (.gamma.) can be performed in
the same reactor, or each can be performed separately in different
reactors. Particularly preferred reactor types are: tubular
reactors, stirred tanks, loop reactors.
[0075] Steps (.alpha.), (.beta.) and (.gamma.) can be performed in
a stirred tank, in which case the stirred tank, according to the
design and mode of operation, is cooled via the reactor shell,
internal cooling surfaces and/or cooling surfaces within a pumped
circulation system. Both in the semi-batchwise process, in which
the product is withdrawn only after the reaction has ended, and in
the continuous process, in which the product is withdrawn
continuously, particular attention should be paid to the metering
rate of the alkylene oxide. This should be set such that, in spite
of the inhibiting action of the carbon dioxide, the alkylene oxides
are depleted quickly enough.
[0076] In a preferred embodiment, the mixture comprising the
activated DMC catalyst that results from steps (.alpha.) and
(.beta.) is reacted further in the same reactor with one or more
alkylene oxide(s), one or more starter substance(s) and carbon
dioxide. In a further preferred embodiment, the mixture comprising
the activated DMC catalyst that results from steps (.alpha.) and
(.beta.) is reacted further with alkylene oxides, one or more
starter substance(s) and carbon dioxide in another reaction vessel
(for example a stirred tank, tubular reactor or loop reactor).
[0077] In the case of a reaction conducted in a tubular reactor,
the mixture comprising the activated DMC catalyst that results from
steps (.alpha.) and (.beta.), one or more H-functional starter
substance(s), one or more alkylene oxide(s) and carbon dioxide are
pumped continuously through a tube. The molar ratios of the
co-reactants vary according to the desired polymer. In a preferred
embodiment, carbon dioxide is metered in here in its liquid or
supercritical form, in order to enable optimal miscibility of the
components. Advantageously, mixing elements for better mixing of
the co-reactants are installed, as sold, for example, by Ehrfeld
Mikrotechnik BTS GmbH, or mixer-heat exchanger elements which
simultaneously improve the mixing and heat removal.
[0078] Loop reactors can likewise be used for performance of steps
(.alpha.), (.beta.) and (.gamma.). These generally include reactors
having recycling of matter, for example a jet loop reactor, which
can also be operated continuously, or a tubular reactor designed in
the form of a loop with suitable apparatuses for the circulation of
the reaction mixture, or a loop of several series-connected tubular
reactors. The use of a jet loop reactor is advantageous especially
because backmixing can be achieved here, such that it is possible
to keep the concentration of free alkylene oxides in the reaction
mixture within the optimal range, preferably in the range from
>0% to 40% by weight, more preferably >0% to 25% by weight,
most preferably >0% to 15% by weight (based in each case on the
weight of the reaction mixture).
[0079] Preferably, steps (.alpha.) and (.beta.) are conducted in a
first reactor, and the resulting reaction mixture is then
transferred into a second reactor for the copolymerization in step
(.gamma.). However, it is also possible to conduct steps (.alpha.),
(.beta.) and (.gamma.) in one reactor.
[0080] The process in step (i) can also be conducted in such a way
that a DMC catalyst activated in a suspension medium in steps
(.alpha.) and (.beta.) is used at first, and the DMC catalyst is
added without prior activation during the copolymerization
(.gamma.). A particularly advantageous feature of the preferred
embodiment of the present invention is thus the ability to use
"fresh" DMC catalysts without activation of a portion of DMC
catalyst which is added continuously in step (.gamma.). An
activation of DMC catalysts to be conducted analogously to step
(.beta.) does not just involve additional attention from the
operator, which results in an increase in the manufacturing costs,
but also requires a pressurized reaction vessel, which also results
in an increase in the capital costs in the construction of a
corresponding production plant. Here, "fresh" DMC catalyst is
defined as unactivated DMC catalyst in solid form or in the form of
a slurry in a starter substance or suspension medium. The ability
of the present process to use fresh unactivated DMC catalyst in
step (.gamma.) enables significant savings in the commercial
preparation of polyether carbonate polyols and is a preferred
embodiment of the present invention.
[0081] The term "continuously" used here can be defined as the mode
of addition of a relevant catalyst or reactant such that an
essentially continuous effective concentration of the DMC catalyst
or the reactant is maintained. The catalyst can be fed in in a
truly continuous manner or in relatively closely spaced increments.
Equally, a continuous addition of starter can be effected in a
truly continuous manner or in increments. There would be no
departure from the present process in adding a DMC catalyst or
reactant incrementally such that the concentration of the materials
added drops essentially to zero for a period of time before the
next incremental addition. However, it is preferable that the DMC
catalyst concentration is kept essentially at the same
concentration during the main portion of the course of the
continuous reaction, and that starter substance is present during
the main portion of the copolymerization process. An incremental
addition of DMC catalyst and/or reactant which essentially does not
affect the nature of the product is nevertheless "continuous" in
that sense in which the term is being used here. One feasible
option is, for example, to provide a recycling loop in which a
portion of the reacting mixture is recycled to a prior point in the
process, as a result of which discontinuities brought about by
incremental additions are smoothed out.
[0082] Optionally, volatile constituents (for example residual
amounts of alkylene oxides, by-products or suspension media) are
removed from the reaction mixture that results from step (i), for
example by distillation under reduced pressure or by thin-film
evaporation.
Step (ii):
[0083] For example, steps (ii-1) and/or (ii-2) can be repeated two
to ten times, in which case, in a preferred embodiment, a mixture
comprising propylene oxide (PO) and ethylene oxide (EO) is used,
with an increase in the proportion by weight of EO on each
repetition. In a particularly preferred embodiment of the
invention, the proportion by weight of EO in the mixture of PO and
EO is increased continuously between a starting PO/EO mixing ratio
and a final PO/EO mixing ratio, the starting PO/EO mixing ratio
corresponding to a PO/EO weight ratio from the weight ratio defined
for step (ii-1), and the final PO/EO mixing ratio corresponding to
a PO/EO weight ratio from the weight ratio defined for step
(ii-2).
[0084] The mean length of the mixed blocks of PO and EO produced in
step (ii-1) or (ii-2) is preferably 1.0 to 20.0 alkylene oxide
units, more preferably 1.5 to 10.0 alkylene oxide units, based in
each case on one OH group of the polyether carbonate polyol.
[0085] Optionally, for performance of step (ii), inert gas (for
example argon or nitrogen) is introduced into the mixture that
results from step (i) at a temperature of 90 to 150.degree. C.,
more preferably of 100 to 140.degree. C., and simultaneously a
reduced pressure is applied (in absolute terms), so as to establish
a pressure in the reactor of 10 mbar to 800 mbar, more preferably
of 50 mbar to 200 mbar (also referred to hereinafter as
"stripping").
[0086] Optionally, step (ii) can be performed by adding DMC
catalyst to the reaction mixture obtained from step (i).
Alternatively, step (ii) can also be performed only with the DMC
catalyst present in the mixture from step (i).
[0087] For performance of step (ii), a solvent not containing any
H-functional groups can be added to the reaction mixture obtained
from step (i).
[0088] Suitable solvents are preferably all polar aprotic, weakly
polar aprotic and nonpolar aprotic solvents, none of which contain
any H-functional groups. The solvent used may also be a mixture of
two or more of these solvents. The following polar aprotic solvents
are mentioned here by way of example: 4-methyl-2-oxo-1,3-dioxolane
(also referred to hereinafter as cyclic propylene carbonate or
cPC), 1,3-dioxolan-2-one (also referred to hereinafter as cyclic
ethylene carbonate or cEC), acetone, methyl ethyl ketone,
acetonitrile, nitromethane, dimethyl sulfoxide, sulfolane,
dimethylformamide, dimethylacetamide and N-methylpyrrolidone. The
group of the nonpolar and weakly polar aprotic solvents includes,
for example, ethers, for example dioxane, diethyl ether, methyl
tert-butyl ether and tetrahydrofuran, esters, for example ethyl
acetate and butyl acetate, hydrocarbons, for example pentane,
n-hexane, benzene and alkylated benzene derivatives (e.g. toluene,
xylene, ethylbenzene) and chlorinated hydrocarbons, for example
chloroform, chlorobenzene, dichlorobenzene and carbon
tetrachloride. Preferred solvents are 4-methyl-2-oxo-1,3-dioxolane,
1,3-dioxolan-2-one, toluene, xylene, ethylbenzene, chlorobenzene
and dichlorobenzene, and mixtures of two or more of these solvents;
particular preference is given to 4-methyl-2-oxo-1,3-dioxolane and
1,3-dioxolan-2-one or a mixture of 4-methyl-2-oxo-1,3-dioxolane and
1,3-dioxolan-2-one.
Step (iii):
[0089] Optionally, step (iii) can be performed by adding DMC
catalyst to the reaction mixture obtained from step (ii).
Alternatively, step (iii) can also be performed only with the DMC
catalyst present in the mixture from step (ii).
[0090] For performance of step (iii), a solvent not containing any
H-functional groups can be added to the reaction mixture obtained
from step (ii). Suitable solvents are the solvents mentioned in
step (ii).
[0091] The metered addition of the ethylene oxide or the mixture of
ethylene oxide and propylene oxide may be followed by a step for
further reaction, which serves to substantially deplete the
alkylene oxides.
[0092] Preferably, volatile constituents (for example residual
amounts of alkylene oxides, by-products or solvents) are removed
from the reaction mixture that results from step (iii), for example
by distillation under reduced pressure or by thin-film
evaporation.
[0093] Preferably, the polyether carbonate polyols that result
after step (iii) have a proportion of primary OH groups of 40 to 90
mol %, more preferably 45 to 85 mol %.
[0094] The mean length of an alkylene oxide block produced in step
(iii) is preferably 1 to 30 alkylene oxide units, more preferably
1.5 to 18 alkylene oxide units, based in each case on one OH group
of the polyether carbonate polyol.
[0095] Preferably, the polyether carbonate polyols that result
after step (iii) have a hydroxyl number of 20 mg KOH/g to 80 mg
KOH/g, more preferably of 25 mg KOH/g to 60 mg KOH/g.
[0096] For steps (ii) and (iii), it has been found that these are
advantageously conducted at 50 to 170.degree. C., preferably at 70
to 150.degree. C., more preferably at 90 to 140.degree. C. and most
preferably at 100 to 130.degree. C.
[0097] Steps (ii) and (iii) can be performed in the same reactor,
or each can be performed separately in different reactors.
Preferred reactor types are: tubular reactors, stirred tanks, loop
reactors. Steps (ii) and (iii) are more preferably performed in a
stirred tank, in which case the product is withdrawn from the
stirred tank after the reaction in step (iii) has ended
(semi-batchwise process). Most preferably, the stirred tank,
according to the design and mode of operation, is cooled via the
reactor shell, internal cooling surfaces and/or cooling surfaces
within a pumped circulation system.
[0098] DMC catalysts for use in the homopolymerization of alkylene
oxides are known in principle from the prior art (see, for example,
U.S. Pat. No. 3,404,109, U.S. Pat. No. 3,829,505, U.S. Pat. No.
3,941,849 and U.S. Pat. No. 5,158,922). DMC catalysts, which are
described, for example, in U.S. Pat. No. 5,470,813, EP-A 700 949,
EP-A 743 093, EP-A 761 708, WO 97/40086, WO 98/16310 and WO
00/47649, have a very high activity and enable the preparation of
polyether carbonate polyols at very low catalyst concentrations,
such that a removal of the catalyst from the finished product is
generally not required. A typical example is that of the highly
active DMC catalysts which are described in EP-A 700 949 and
contain, as well as a double metal cyanide compound (e.g. zinc
hexacyanocobaltate(III)) and an organic complex ligand (e.g.
tert-butanol), also a polyether having a number-average molecular
weight greater than 500 g/mol.
[0099] The inventive DMC catalysts are preferably obtained by
[0100] (a) in the first step reacting an aqueous solution of a
metal salt with the aqueous solution of a metal cyanide salt in the
presence of one or more organic complex ligands, for example of an
ether or alcohol, [0101] (b) with removal in the second step of the
solid from the suspension obtained from (i) by known techniques
(such as centrifugation or filtration), [0102] (ci) with optional
washing in a third step of the isolated solid with an aqueous
solution of an organic complex ligand (for example by resuspending
and optionally reisolating by filtration or centrifugation), [0103]
(d) with subsequent drying of the solid obtained, optionally after
pulverization, at temperatures of generally 20-120.degree. C. and
at pressures of generally 0.1 mbar to standard pressure (1013
mbar), and with addition, in the first step or immediately after
the precipitation of the double metal cyanide compound (second
step), of one or more organic complex ligands, preferably in excess
(based on the double metal cyanide compound), and optionally of
further complex-forming components.
[0104] The double metal cyanide compounds present in the inventive
DMC catalysts are the reaction products of water-soluble metal
salts and water-soluble metal cyanide salts.
[0105] For example, an aqueous solution of zinc chloride
(preferably in excess based on the metal cyanide salt, for example
potassium hexacyanocobaltate) and potassium hexacyanocobaltate are
mixed and then dimethoxyethane (glyme) or tert-butanol (preferably
in excess, based on zinc hexacyanocobaltate) is added to the
suspension formed.
[0106] Metal salts suitable for preparation of the double metal
cyanide compounds preferably have the general formula (II)
M(X).sub.n (II)
where M is selected from the metal cations Zn.sup.2+, Fe.sup.2+,
Ni.sup.2+, Mn.sup.2+, Co.sup.2+, Sr.sup.2+, Sn.sup.2+, Pb.sup.2+
and Cu.sup.2+; M is preferably Zn.sup.2+, Fe.sup.2+, Co.sup.2+ or
Ni.sup.2+, X is one or more (i.e. different) anions, preferably an
anion selected from the group of the halides (i.e. fluoride,
chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate,
thiocyanate, isocyanate, isothiocyanate, carboxylate, oxalate and
nitrate; n is 1 when X=sulfate, carbonate or oxalate and n is 2
when X=halide, hydroxide, carboxylate, cyanate, thiocyanate,
isocyanate, isothiocyanate or nitrate, or suitable metal salts have
the general formula (III)
M.sub.r(X).sub.3 (III)
where M is selected from the metal cations Fe.sup.3+, Al.sup.3+,
Co.sup.3+ and Cr.sup.3+, X is one or more (i.e. different) anions,
preferably an anion selected from the group of the halides (i.e.
fluoride, chloride, bromide, iodide), hydroxide, sulfate,
carbonate, cyanate, thiocyanate, isocyanate, isothiocyanate,
carboxylate, oxalate and nitrate; r is 2 when X=sulfate, carbonate
or oxalate and r is 1 when X=halide, hydroxide, carboxylate,
cyanate, thiocyanate, isocyanate, isothiocyanate or nitrate, or
suitable metal salts have the general formula (IV)
M(X).sub.s (IV)
where M is selected from the metal cations Mo.sup.4+, V.sup.4+ and
W.sup.4+, X is one or more (i.e. different) anions, preferably an
anion selected from the group of the halides (i.e. fluoride,
chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate,
thiocyanate, isocyanate, isothiocyanate, carboxylate, oxalate and
nitrate; s is 2 when X=sulfate, carbonate or oxalate and s is 4
when X=halide, hydroxide, carboxylate, cyanate, thiocyanate,
isocyanate, isothiocyanate or nitrate, or suitable metal salts have
the general formula (V)
M(X).sub.t (V)
where M is selected from the metal cations Mo.sup.6+ and W.sup.6+,
X is one or more (i.e. different) anions, preferably an anion
selected from the group of the halides (i.e. fluoride, chloride,
bromide, iodide), hydroxide, sulfate, carbonate, cyanate,
thiocyanate, isocyanate, isothiocyanate, carboxylate, oxalate and
nitrate; t is 3 when X=sulfate, carbonate or oxalate and t is 6
when X=halide, hydroxide, carboxylate, cyanate, thiocyanate,
isocyanate, isothiocyanate or nitrate.
[0107] Examples of suitable metal salts are zinc chloride, zinc
bromide, zinc iodide, zinc acetate, zinc acetylacetonate, zinc
benzoate, zinc nitrate, iron(II) sulfate, iron(II) bromide,
iron(II) chloride, iron(III) chloride, cobalt(II) chloride,
cobalt(II) thiocyanate, nickel(II) chloride and nickel(II) nitrate.
It is also possible to use mixtures of different metal salts.
[0108] Metal cyanide salts suitable for preparation of the double
metal cyanide compounds preferably have the general formula
(VI)
(Y).sub.aM'(CN).sub.b(A).sub.c (VI)
where M' is selected from one or more metal cations from the group
consisting of Fe(II), Fe(III), Co(II), Co(III), Cr(II), Cr(III),
Mn(II), Mn(III), Ir(III), Ni(II), Rh(III), Ru(II), V(IV) and V(V);
M' is preferably one or more metal cations from the group
consisting of Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III)
and Ni(II), Y is selected from one or more metal cations from the
group consisting of alkali metal (i.e. Li.sup.+, Na.sup.+, K.sup.+,
Rb.sup.+) and alkaline earth metal (i.e. Be.sup.2+, Mg.sup.2+,
Ca.sup.2+, Sr.sup.2+, Ba.sup.2+), A is selected from one or more
anions from the group consisting of halides (i.e. fluoride,
chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate,
thiocyanate, isocyanate, isothiocyanate, carboxylate, azide,
oxalate and nitrate, and a, b and c are integers, where the values
of a, b and c are chosen so as to give electronic neutrality of the
metal cyanide salt; a is preferably 1, 2, 3 or 4; b is preferably
4, 5 or 6; c preferably has a value of 0.
[0109] Examples of suitable metal cyanide salts are sodium
hexacyanocobaltate(III), potassium hexacyanocobaltate(III),
potassium hexacyanoferrate(II), potassium hexacyanoferrate(III),
calcium hexacyanocobaltate(III) and lithium
hexacyanocobaltate(III).
[0110] Preferred double metal cyanide compounds present in the
inventive DMC catalysts are compounds of the general formula
(VII)
Mx[M'x,(CN)y]z (VII)
in which M is as defined in formula (II) to (V) and M' is as
defined in formula (VI), and x, x', y and z are integer values and
are chosen so as to give electronic neutrality of the double metal
cyanide compound.
[0111] Preferably,
x=3, x'=1, y=6 and z=2,
M=Zn(II), Fe(II), Co(II) or Ni(II) and
M'=Co(III), Fe(III), Cr(III) or Ir(III).
[0112] Examples of suitable double metal cyanide compounds a) are
zinc hexacyanocobaltate(III), zinc hexacyanoiridate(III), zinc
hexacyanoferrate(III) and cobalt(II) hexacyanocobaltate(III).
Further examples of suitable double metal cyanide compounds can be
found, for example, in U.S. Pat. No. 5,158,922 (column 8 lines
29-66). Particular preference is given to using zinc
hexacyanocobaltate(III).
[0113] The organic complex ligands added in the preparation of the
DMC catalysts are disclosed, for example, in U.S. Pat. No.
5,158,922 (see especially column 6 lines 9 to 65), U.S. Pat. No.
3,404,109, U.S. Pat. No. 3,829,505, U.S. Pat. No. 3,941,849, EP-A
700 949, EP-A 761 708, JP 4 145 123, U.S. Pat. No. 5,470,813, EP-A
743 093 and WO-A 97/40086). For example, the organic complex
ligands used are water-soluble, organic compounds having
heteroatoms such as oxygen, nitrogen, phosphorus or sulfur, which
can form complexes with the double metal cyanide compound.
Preferred organic complex ligands are alcohols, aldehydes, ketones,
ethers, esters, amides, ureas, nitriles, sulfides and mixtures
thereof. Particularly preferred organic complex ligands are
aliphatic ethers (such as dimethoxyethane), water-soluble aliphatic
alcohols (such as ethanol, isopropanol, n-butanol, isobutanol,
sec-butanol, tert-butanol, 2-methyl-3-buten-2-ol and
2-methyl-3-butyn-2-ol), compounds containing both aliphatic or
cycloaliphatic ether groups and aliphatic hydroxyl groups (for
example ethylene glycol mono-tert-butyl ether, diethylene glycol
mono-tert-butyl ether, tripropylene glycol monomethyl ether and
3-methyl-3-oxetanemethanol). Most preferred organic complex ligands
are selected from one or more compounds from the group consisting
of dimethoxyethane, tert-butanol, 2-methyl-3-buten-2-ol,
2-methyl-3-butyn-2-ol, ethylene glycol mono-tert-butyl ether and
3-methyl-3-oxetanemethanol.
[0114] Optionally, in the preparation of the inventive DMC
catalysts, one or more complex-forming component(s) from the
compound classes of the polyethers, polyesters, polycarbonates,
polyalkylene glycol sorbitan esters, polyalkylene glycol glycidyl
ethers, polyacrylamide, poly(acrylamide-co-acrylic acid),
polyacrylic acid, poly(acrylic acid-co-maleic acid),
polyacrylonitrile, polyalkyl acrylates, polyalkyl methacrylates,
polyvinyl methyl ethers, polyvinyl ethyl ethers, polyvinyl acetate,
polyvinyl alcohol, poly-N-vinylpyrrolidone,
poly(N-vinylpyrrolidone-co-acrylic acid), polyvinyl methyl ketone,
poly(4-vinylphenol), poly(acrylic acid-co-styrene), oxazoline
polymers, polyalkyleneimines, maleic acid and maleic anhydride
copolymers, hydroxyethyl cellulose and polyacetals, or of the
glycidyl ethers, glycosides, carboxylic esters of polyhydric
alcohols, gallic acids or salts, esters or amides thereof,
cyclodextrins, phosphorus compounds, .alpha.,.beta.-unsaturated
carboxylic esters or ionic surface- or interface-active compounds,
are used.
[0115] Preferably, in the preparation of the inventive DMC
catalysts, in the first step, the aqueous solutions of the metal
salt (e.g. zinc chloride), used in a stoichiometric excess (at
least 50 mol %) based on metal cyanide salt (i.e. at least a molar
ratio of metal salt to metal cyanide salt of 2.25:1.00), and the
metal cyanide salt (e.g. potassium hexacyanocobaltate) are
converted in the presence of the organic complex ligand (e.g.
tert-butanol), forming a suspension comprising the double metal
cyanide compound (e.g. zinc hexacyanocobaltate), water, excess
metal salt, and the organic complex ligands.
[0116] This organic complex ligand may be present in the aqueous
solution of the metal salt and/or of the metal cyanide salt, or it
is added directly to the suspension obtained after precipitation of
the double metal cyanide compound. It has been found to be
advantageous to mix the aqueous solutions of the metal salt and of
the metal cyanide salt, and the organic complex ligands by stirring
vigorously. Optionally, the suspension formed in the first step is
subsequently treated with a further complex-forming component. The
complex-forming component is preferably used in a mixture with
water and organic complex ligand. A preferred process for
performing the first step (i.e. the preparation of the suspension)
is effected using a mixing nozzle, more preferably using a jet
disperser, as described in WO-A 01/39883.
[0117] In the second step, the solid (i.e. the precursor of the
inventive catalyst) is isolated from the suspension by known
techniques, such as centrifugation or filtration.
[0118] In a preferred execution variant, the isolated solid is
subsequently washed in a third process step with an aqueous
solution of the organic complex ligand (for example by resuspension
and subsequent reisolation by filtration or centrifugation). In
this way, it is possible to remove, for example, water-soluble
by-products such as potassium chloride from the inventive catalyst.
Preferably, the amount of the organic complex ligand in the aqueous
wash solution is between 40 and 80% by weight, based on the overall
solution.
[0119] Optionally, in the third step, further complex-forming
component is added to the aqueous wash solution, preferably in the
range between 0.5 and 5% by weight, based on the overall
solution.
[0120] Moreover, it is advantageous to wash the isolated solid more
than once. Preferably, in a first wash step (iii-1), an aqueous
solution of the unsaturated alcohol is used for washing (for
example by resuspension and subsequent reisolation by filtration or
centrifugation), in order to remove, for example, water-soluble
by-products such as potassium chloride from the inventive catalyst
in this way. Especially preferably, the amount of the unsaturated
alcohol in the aqueous wash solution is between 40 and 80% by
weight, based on the overall solution in the first wash step. In
the further wash steps (iii-2), either the first wash step is
repeated once or more than once, preferably once to three times,
or, preferably, a nonaqueous solution, for example a mixture or
solution of unsaturated alcohol and further complex-forming
components (preferably in the range between 0.5 and 5% by weight,
based on the total amount of the wash solution in step (iii-2)), is
used as a wash solution to wash the solid once or more than once,
preferably once to three times.
[0121] The isolated and optionally washed solid is subsequently,
optionally after pulverization, dried at temperatures of generally
20-100.degree. C. and at pressures of generally 0.1 mbar to
standard pressure (1013 mbar).
[0122] A preferred process for isolating the inventive DMC
catalysts from the suspension by filtration, filtercake washing and
drying is described in WO-A 01/80994.
[0123] The polyether carbonate polyols obtainable by the process
according to the invention have a low content of by-products and
can be processed without any problem, especially by reaction with
di- and/or polyisocyanates to give polyurethanes, especially
flexible polyurethane foams. For polyurethane applications, it is
preferable to use polyether carbonate polyols based on an
H-functional starter substance having a functionality of at least
2. In addition, the polyether carbonate polyols obtainable by the
process according to the invention can be used in applications such
as washing and cleaning composition formulations, drilling fluids,
fuel additives, ionic and nonionic surfactants, lubricants, process
chemicals for papermaking or textile manufacture, or cosmetic
formulations. The person skilled in the art is aware that,
depending on the respective field of use, the polyether carbonate
polyols to be used have to fulfill certain material properties, for
example molecular weight, viscosity, functionality and/or hydroxyl
number.
Flexible Polyurethane Foams
[0124] The invention preferably provides a process for producing
flexible polyurethane foams having an apparent density to DIN EN
ISO 3386-1-98 in the range from .gtoreq.10 kg/m.sup.3 to
.ltoreq.150 kg/m.sup.3, preferably from .gtoreq.20 kg/m.sup.3 to
.ltoreq.70 kg/m.sup.3, and an indentation hardness to DIN EN ISO
3386-1-98 in the range from .gtoreq.0.5 kPa to .ltoreq.20 kPa (at
40% deformation and 4th cycle), by reaction of component A (polyol
formulation) comprising [0125] A1 100 to 10 parts by weight,
preferably 100 to 50 parts by weight, more preferably 100 parts by
weight (based on the sum total of the parts by weight of components
A1 and A2), of polyether carbonate polyol obtainable by the process
of the present invention, [0126] A2 0 to 90 parts by weight,
preferably 0 to 50 parts by weight (based on the sum total of the
parts by weight of components A1 and A2), of conventional polyether
polyol; more preferably, component A is free of conventional
polyether polyol, [0127] A3 0.5 to 25 parts by weight, preferably 2
to 5 parts by weight (based on the sum total of the parts by weight
of components A1 and A2), of water and/or physical blowing agents,
[0128] A4 0.05 to 10 parts by weight, preferably 0.2 to 4 parts by
weight (based on the sum total of the parts by weight of components
A1 and A2), of auxiliaries and additives such as [0129] a)
catalysts, [0130] b) surface-active additives, [0131] c) pigments
or flame retardants, [0132] A5 0 to 10 parts by weight, preferably
0 to 5 parts by weight (based on the sum total of the parts by
weight of components A1 and A2), of compounds having hydrogen atoms
reactive toward isocyanates and having a molecular weight of
62-399, with component B comprising polyisocyanates, where the
preparation is effected at an index of 50 to 250, preferably 70 to
130, more preferably 75 to 115, and where the stated parts by
weight of components A1 to A5 are normalized such that the sum
total of the parts by weight of components A1+A2 in the composition
adds up to 100.
Component A1
[0133] The preparation of component A1 in steps (i), (ii) and (iii)
has already been elucidated above in connection with the
preparation process for the polyether carbonate polyols.
Component A2
[0134] Starting components according to component A2 are
conventional polyether polyols. In the context of the invention,
conventional polyether polyols refer to compounds that are alkylene
oxide addition products of starter compounds with
Zerewitinoff-active hydrogen atoms, i.e. polyether polyols having a
hydroxyl number to DIN 53240 of .gtoreq.15 mg KOH/g to .ltoreq.80
mg KOH/g, preferably of .gtoreq.20 mg KOH/g to .ltoreq.60 mg
KOH/g.
[0135] Starter compounds having Zerewitinoff-active hydrogen atoms
that are used for the conventional polyether polyols usually have
functionalities of 2 to 6, preferably of 3, and the starter
compounds are preferably hydroxy-functional. Examples of
hydroxy-functional starter compounds are propylene glycol, ethylene
glycol, diethylene glycol, dipropylene glycol, butane-1,2-diol,
butane-1,3-diol, butane-1,4-diol, hexanediol, pentanediol,
3-methylpentane-1,5-diol, dodecane-1,12-diol, glycerol,
trimethylolpropane, triethanolamine, pentaerythritol, sorbitol,
sucrose, hydroquinone, catechol, resorcinol, bisphenol F, bisphenol
A, 1,3,5-trihydroxybenzene, methylol-containing condensates of
formaldehyde and phenol or melamine or urea. The starter compound
used is preferably glycerol and/or trimethylolpropane.
[0136] Suitable alkylene oxides are, for example, ethylene oxide,
propylene oxide, 1,2-butylene oxide or 2,3-butylene oxide and
styrene oxide. Preference is given to feeding propylene oxide and
ethylene oxide into the reaction mixture individually, in a mixture
or successively. If the alkylene oxides are metered in
successively, the products produced contain polyether chains having
block structures. Products having ethylene oxide end blocks are
characterized, for example, by elevated concentrations of primary
end groups which impart advantageous isocyanate reactivity to the
systems.
Component A3
[0137] Water and/or physical blowing agents are used as component
A3. Physical blowing agents used are, for example, carbon dioxide
and/or volatile organic substances.
Component A4
[0138] Auxiliaries and additives are used as component A4, such as
[0139] a) catalysts (activators), [0140] b) surface-active
additives (surfactants), such as emulsifiers and foam stabilizers,
especially those having low emissions, for example products from
the Tegostab.RTM. LF series, [0141] c) additives such as reaction
retardants (for example acidic substances such as hydrochloric acid
or organic acyl halides), cell regulators (for example paraffins or
fatty alcohols or dimethylpolysiloxanes), pigments, dyes, flame
retardants (for example tricresyl phosphate), stabilizers against
aging and weathering effects, plasticizers, fungistatic and
bacteriostatic substances, fillers (for example barium sulfate,
kieselguhr, carbon black or whiting) and separating agents.
[0142] These auxiliaries and additives for optional additional use
are described, for example, in EP-A 0 000 389, pages 18-21. Further
examples of auxiliaries and additives for optional additional use
in accordance with the invention and details of the manner of use
and mode of action of these auxiliaries and additives are described
in Kunststoff-Handbuch [Plastics Handbook], volume VII, edited by
G. Oertel, Carl-Hanser-Verlag, Munich, 3rd edition, 1993, for
example on pages 104-127.
[0143] Preferred catalysts are aliphatic tertiary amines (for
example trimethylamine, tetramethylbutanediamine), cycloaliphatic
tertiary amines (for example 1,4-diaza[2.2.2]bicyclooctane,
aliphatic amino ethers (for example dimethylaminoethyl ether and
N,N,N-trimethyl-N-hydroxyethylbisaminoethyl ether), cycloaliphatic
amino ethers (for example N-ethylmorpholine), aliphatic amidines,
cycloaliphatic amidines, urea, derivatives of urea (for example
aminoalkylureas; see, for example, EP-A 0 176 013, especially
(3-dimethylaminopropylamino)urea), and tin catalysts (for example
dibutyltin oxide, dibutyltin dilaurate, tin octoate).
[0144] Particularly preferred catalysts are [0145] .alpha.) urea,
derivatives of urea and/or [0146] .beta.) amines and amino ethers
each containing a functional group which reacts chemically with the
isocyanate. Preferably, the functional group is a hydroxyl group, a
primary or secondary amino group. These particularly preferred
catalysts have the advantage of having greatly reduced migration
and emission characteristics.
[0147] Examples of particularly preferred catalysts include:
(3-dimethylaminopropylamino)urea,
2-(2-dimethylaminoethoxyl)ethanol,
N,N-bis(3-dimethylaminopropyl)-N-isopropanolamine,
N,N,N-trimethyl-N-hydroxyethylbisaminoethyl ether and
3-dimethylaminopropylamine.
Component A5
[0148] Optionally, compounds having at least two hydrogen atoms
reactive toward isocyanate and a molecular weight of 32 to 399 are
used as component A5. These are understood to mean compounds having
hydroxyl groups and/or amino groups and/or thiol groups and/or
carboxyl groups, preferably compounds having hydroxyl groups and/or
amino groups, which serve as chain extenders or crosslinkers. These
compounds generally have 2 to 8, preferably 2 to 4, hydrogen atoms
reactive toward isocyanates. For example, ethanolamine,
diethanolamine, triethanolamine, sorbitol and/or glycerol can be
used as component A5. Further examples of compounds for component
A5 are described in EP-A 0 007 502, pages 16-17.
Component B
[0149] Suitable polyisocyanates are aliphatic, cycloaliphatic,
araliphatic, aromatic and heterocyclic polyisocyanates, as
described, for example, by W. Siefken in Justus Liebigs Annalen der
Chemie, 562, pages 75 to 136, for example those of the formula
(VIII)
Q(NCO).sub.n, (VIII) [0150] in which [0151] n=2-4, preferably 2-3,
[0152] and [0153] Q is an aliphatic hydrocarbyl radical having 2-18
and preferably 6-10 carbon atoms, a cycloaliphatic hydrocarbyl
radical having 4-15 and preferably 6-13 carbon atoms or an
araliphatic hydrocarbyl radical having 8-15 and preferably 8-13
carbon atoms.
[0154] For example, the polyisocyanates are those as described in
EP-A 0 007 502, pages 7-8. Preference is generally given to the
readily industrially available polyisocyanates, for example
tolylene 2,4- and 2,6-diisocyanate and any desired mixtures of
these isomers ("TDI"); polyphenylpolymethylene polyisocyanates as
prepared by aniline-formaldehyde condensation and subsequent
phosgenation ("crude MDI"), and polyisocyanates having carbodiimide
groups, urethane groups, allophanate groups, isocyanurate groups,
urea groups or biuret groups ("modified polyisocyanates"),
especially those modified polyisocyanates which derive from
tolylene 2,4- and/or 2,6-diisocyanate or from diphenylmethane 4,4'-
and/or 2,4'-diisocyanate. The polyisocyanate used is preferably at
least one compound selected from the group consisting of tolylene
2,4- and 2,6-diisocyanate, diphenylmethane 4,4'- and 2,4'- and
2,2'-diisocyanate and polyphenylpolymethylene polyisocyanate
("multiring MDI"); the polyisocyanate used is more preferably a
mixture comprising diphenylmethane 4,4'-diisocyanate,
diphenylmethane 2,4'-diisocyanate and polyphenylpolymethylene
polyisocyanate.
[0155] For production of the flexible polyurethane foams, the
reaction components are reacted by the one-stage process known per
se, often using mechanical equipment, for example that described in
EP-A 355 000. Details of processing equipment which is also an
option in accordance with the invention are described in
Kunststoff-Handbuch, volume VII, edited by Vieweg and Hochtlen,
Carl-Hanser-Verlag, Munich 1993, for example on pages 139 to
265.
[0156] The flexible polyurethane foams can be produced as molded
foams or else as slabstock foams. The invention therefore provides
a process for producing the flexible polyurethane foams, the
flexible polyurethane foams produced by these processes, the
flexible slabstock polyurethane foams or molded polyurethane foams
produced by these processes, the use of the flexible polyurethane
foams for production of moldings and the moldings themselves. The
flexible polyurethane foams obtainable according to the invention
find the following uses, for example: furniture padding, textile
inserts, mattresses, automobile seats, headrests, armrests, sponges
and construction elements.
[0157] The index indicates the percentage ratio of the amount of
isocyanate actually used to the stoichiometric amount of isocyanate
groups (NCO) amount, i.e. that calculated for the conversion of the
OH equivalents.
Index=[(amount of isocyanate used):(amount of isocyanate
calculated)]100 (IX)
EXAMPLES
Methods
[0158] Apparent density was determined to DIN EN ISO 3386-1-98.
[0159] Indentation hardness was determined to DIN EN ISO 3386-1-98
(at 40% deformation and 4th cycle).
[0160] Tensile strength and elongation at break were determined to
DIN EN ISO 1798.
[0161] The compression sets CS 50% and CS 75% were determined to
DIN EN ISO 1856-2001-03 at 50% and 75% compression
respectively.
[0162] The compression set CS 90%/22 h/70.degree. C. was determined
to DIN EN ISO 1856-2008 at 90% compression.
OH Number:
[0163] The OH numbers were determined by the method of DIN
53240.
Viscosity:
[0164] The viscosities were determined by means of a rotary
viscometer (Physica MCR 51, manufacturer: Anton Paar) at a shear
rate of 5 s.sup.-1 by the method of DIN 53018.
GPC:
[0165] The number-average molecular weight M.sub.n and the
weight-average molecular weight M.sub.w, and also the
polydispersity (M.sub.w/M.sub.n), of the products was determined by
means of gel permeation chromatography (GPC). The procedure of DIN
55672-1 was followed: "Gel permeation chromatography, Part
1--Tetrahydrofuran as eluent" (SECurity GPC System from PSS Polymer
Service, flow rate 1.0 ml/min; columns: 2.times.PSS SDV linear M,
8.times.300 mm, 5 .mu.m; RID detector). Polystyrene samples of
known molar mass were used for calibration.
Primary OH Groups:
[0166] Determination of the molar proportion of the primary OH
groups: by means of .sup.1H NMR (Bruker DPX 400,
deuterochloroform):
[0167] To determine the content of primary OH groups, the polyol
samples were first peracetylated.
[0168] This was done using the following peracetylation mixture:
[0169] 9.4 g of acetic anhydride p.A. [0170] 1.6 g of acetic acid
p.A. [0171] 100 mL of pyridine p.A.
[0172] For the peracetylation reaction, 10 g of polyol (polyether
carbonate polyol or polyether polyol) were weighed into a 300 mL
flanged Erlenmeyer flask. The volume of peracetylation mixture was
guided by the OH number of the polyol to be peracetylated, rounding
the OH number of the polyol up to the next multiple of 10 (based in
each case on 10 g of polyol); for every 10 mg KOH/g, 10 mL of
peracetylation mixture are then added. For example, 50 mL of
peracetylation mixture were correspondingly added to the sample of
10 g of a polyol having an OH number=45.1 mg KOH/g.
[0173] After the addition of glass boiling chips, the flanged
Erlenmeyer flask was provided with a riser tube (air condenser) and
the sample was boiled under gentle reflux for 75 min. The sample
mixture was then transferred into a 500 mL round-bottom flask, and
volatile constituents (essentially pyridine, acetic acid and excess
acetic anhydride) were distilled off at 80.degree. C. and 10 mbar
(absolute) over a period of 30 min. The distillation residue was
then admixed three times with 100 mL each time of cyclohexane
(toluene was used as an alternative in the cases in which the
distillation residue did not dissolve in cyclohexane), and volatile
constituents were removed each time at 80.degree. C. and 400 mbar
(absolute) for 15 min. Subsequently, volatile constituents of the
sample were removed at 100.degree. C. and 10 mbar (absolute) for
one hour.
[0174] To determine the molar proportions of primary and secondary
OH end groups in the polyol, the sample thus prepared was dissolved
in deuterated chloroform and analyzed by means of .sup.1H NMR (from
Bruker, DPX 400, 400 MHz, zg30 pulse program, wait time d1: 10 s,
64 scans). The relevant resonances in the .sup.1H NMR (relative to
TMS=0 ppm) are as follows:
[0175] Methyl signal of a peracetylated secondary OH end group:
2.04 ppm
[0176] Methyl signal of a peracetylated primary OH end group: 2.07
ppm
[0177] The molar proportion of secondary and primary OH end groups
is then found as follows:
Proportion of secondary OH end groups
(CH--OH)=A(2.04)/(A(2.04)+A(2.07))*100% (X)
Proportion of primary OH end groups
(CH2-OH)=A(2.07)/(A(2.04)+A(2.07))*100% (XI)
[0178] In the formulae (X) and (XI), A represents the area of the
resonance at 2.04 ppm or 2.07 ppm.
CO.sub.2 Content in the Polyether Carbonate Polyol:
[0179] The proportion of incorporated CO.sub.2 in the resulting
polyether carbonate polyol and the ratio of propylene carbonate to
polyether carbonate polyol were determined by means of .sup.1H NMR
(from Bruker, DPX 400, 400 MHz, zg30 pulse program, wait time d1:
10 s, 64 scans). Each sample was dissolved in deuterated
chloroform. The relevant resonances in the .sup.1H NMR (relative to
TMS=0 ppm) are as follows:
[0180] Cyclic carbonate (which was formed as a by-product) with
resonance at 4.5 ppm, carbonate resulting from carbon dioxide
incorporated in the polyether carbonate polyol with resonances at
5.1 to 4.8 ppm, unreacted PO with resonance at 2.4 ppm, polyether
polyol (i.e. without incorporated carbon dioxide) with resonances
at 1.2 to 1.0 ppm, the octane-1,8-diol incorporated as starter
molecule (if present) with a resonance at 1.6 to 1.52 ppm.
[0181] The mole fraction of the carbonate incorporated in the
polymer in the reaction mixture is calculated as follows by formula
(XII), using the following abbreviations: [0182] A(4.5)=area of the
resonance at 4.5 ppm for cyclic carbonate (corresponding to a
hydrogen atom) [0183] A(5.1-4.8)=area of the resonance at 5.1-4.8
ppm for polyether carbonate polyol and a hydrogen atom for cyclic
carbonate [0184] A(2.4)=area of the resonance at 2.4 ppm for free
unreacted PO [0185] A(1.2-1.0)=area of the resonance at 1.2-1.0 ppm
for polyether polyol [0186] A(1.6-1.52)=area of the resonance at
1.6 to 1.52 ppm for octane-1,8-diol (starter), if present
[0187] Taking account of the relative intensities, conversion was
effected by the following formula (XII) for carbonate bound in
polymer form ("linear carbonate" LC) in the reaction mixture in mol
%:
( XII ) ##EQU00001## LC = A ( 5.1 - 4.8 ) - A ( 4.5 ) A ( 5.1 - 4.8
) + A ( 2.4 ) + 0.33 * A ( 1.2 - 1.0 ) + 0.25 * A ( 1.6 - 1.52 ) *
100 ##EQU00001.2##
[0188] The proportion by weight (in % by weight) of polymer-bound
carbonate (LC') in the reaction mixture was calculated by formula
(XIII):
LC ' = [ A ( 5.1 - 4.8 ) - A ( 4.5 ) ] * 102 D * 100 % ( XIII )
##EQU00002##
where the value of D ("denominator" D) is calculated by formula
(XIV):
D=[A(5.1-4.8)-A(4.5)]*102+A(4.5)*102+A(2.4)*58+0.33*A(1.2-1.0)*58+0.25*A-
(1.6-1.52)*146 (XIV)
[0189] The factor of 102 results from the sum total of the molar
masses of CO.sub.2 (molar mass 44 g/mol) and of propylene oxide
(molar mass 58 g/mol), the factor of 58 results from the molar mass
of propylene oxide and the factor of 146 results from the molar
mass of the octane-1,8-diol starter used (if present).
[0190] The proportion by weight (in % by weight) of cyclic
carbonate (CC') in the reaction mixture was calculated by formula
(XV):
CC ' = A ( 4.5 ) * 102 D * 100 % ( XV ) ##EQU00003##
where the value of D is calculated by formula (XIV).
[0191] In order to calculate the composition based on the polymer
content (consisting of polyether polyol which has been formed from
starter and propylene oxide during the activation steps which take
place under CO.sub.2-free conditions, and polyether carbonate
polyol formed from starter, propylene oxide and carbon dioxide
during the activation steps which take place in the presence of
CO.sub.2 and during the copolymerization) from the values for the
composition of the reaction mixture, the non-polymeric constituents
of the reaction mixture (i.e. cyclic propylene carbonate and any
unconverted propylene oxide present) were eliminated by
calculation. The proportion by weight of the repeat carbonate units
in the polyether carbonate polyol was converted to a proportion by
weight of carbon dioxide by means of a factor F=44/(44+58). The
proportion of the CO.sub.2 content in the polyether carbonate
polyol is normalized to the proportion of the polyether carbonate
polyol molecule which has been formed in the copolymerization and
any activation steps in the presence of CO.sub.2 (i.e. the
proportion of the polyether carbonate polyol molecule which results
from the starter (octane-1,8-diol, if present) and from the
reaction of the starter with epoxide which has been added under
CO.sub.2-free conditions was not taken into account here).
Raw Materials Used:
[0192] The DMC catalyst used in all the examples was DMC catalyst
prepared according to example 6 in WO 01/80994 A1.
[0193] Cyclic propylene carbonate: from Acros
A. Preparation of Precursors in Step (i)
Polyether Carbonate Polyol Precursor A:
[0194] A 50 liter pressure reactor having a gas metering unit was
initially charged with 9.5 g of DMC catalyst and 10 680 g of a
trifunctional poly(oxypropylene)polyol having OH number=237 mg
KOH/g as starter. The reactor was heated up to 130.degree. C. and
inertized by three times evacuating to 200 mbar (absolute) and
repeatedly charging with nitrogen. At 130.degree. C. and in the
absence of CO.sub.2, 1310 g of propylene oxide were metered rapidly
into the reactor. The onset of the reaction was perceptible by a
temperature peak ("hotspot") and by a pressure drop to about the
starting pressure (about 1 bar). After the first pressure drop, a
further 880 g of PO and then 740 g of PO were metered in rapidly,
which again resulted in a temperature peak and a pressure drop each
time. After the reactor had been charged with 54 bar (absolute) of
CO.sub.2, 1330 g of PO were metered in quickly, which again
resulted in a temperature peak. At the same time, the pressure of
carbon dioxide CO.sub.2 started to fall. The pressure was regulated
such that the new CO.sub.2 was added when the value fell below the
target. Only thereafter was the remaining propylene oxide (27 360
g) pumped continuously into the reactor at about 7.0 kg/h, while
the temperature was lowered to 107.degree. C. within about 30 min.
After the addition of PO had ended, stirring was continued at
reaction temperature and the above-specified pressure for about
another 60 minutes. By thin-film evaporation, volatile constituents
were finally removed from the product.
Product Properties:
[0195] OH number: 58.3 mg KOH/g
[0196] Viscosity (25.degree. C.): 4020 mPas
[0197] CO2 content: 14.0% by weight.
Polyether Carbonate Polyol Precursor B:
[0198] A 50 liter pressure reactor having a gas metering unit was
initially charged with 9.5 g of DMC catalyst and 10 680 g of a
trifunctional poly(oxypropylene)polyol having OH number=237 mg
KOH/g as starter. The reactor was heated up to 130.degree. C. and
inertized by three times evacuating to 200 mbar (absolute) and
repeatedly charging with nitrogen. At 130.degree. C. and in the
absence of CO.sub.2, 1310 g of propylene oxide were metered rapidly
into the reactor. The onset of the reaction was perceptible by a
temperature peak ("hotspot") and by a pressure drop to about the
starting pressure (about 1 bar). After the first pressure drop, a
further 880 g of PO were metered in rapidly, which again resulted
in a temperature peak and a pressure drop each time. After the
reactor had been charged with 54 bar (absolute) of CO.sub.2, 1330 g
of PO were metered in quickly, which again resulted in a
temperature peak. At the same time, the pressure of carbon dioxide
CO.sub.2 started to fall. The pressure was regulated such that the
new CO.sub.2 was added when the value fell below the target. Only
thereafter was the remaining propylene oxide (27 360 g) pumped
continuously into the reactor at about 7.0 kg/h, while the
temperature was lowered to 104.degree. C. within about 40 min After
the addition of PO had ended, stirring was continued at reaction
temperature and the above-specified pressure for about another 60
minutes. By thin-film evaporation, volatile constituents were
finally removed from the product.
Product Properties:
[0199] OH number: 56.4 mg KOH/g
[0200] Viscosity (25.degree. C.): 7265 mPas
[0201] CO2 content: 15.8% by weight.
Polyether Polyol Precursor A:
[0202] A 2 liter stainless steel pressure reactor was initially
charged with 362 g of a trifunctional poly(oxypropylene)polyol with
OH number=237 mg KOH/g and 0.28 g of DMC catalyst under nitrogen,
and then heated to 130.degree. C. After nitrogen stripping at 0.1
bar (absolute) for 30 min, the reactor was cooled to 105.degree. C.
and 1038 g of propylene oxide were metered into the reactor at this
temperature while stirring (800 rpm) within 110 min After further
reaction for 45 min, volatile constituents were distilled off under
reduced pressure at 90.degree. C. for 30 minutes and then the
reaction mixture was cooled to room temperature.
Product Properties:
[0203] OH number: 57.9 mg KOH/g
[0204] Viscosity (25.degree. C.): 553 mPas
B. Conversion of the Precursors in Steps (ii) and (iii)
Example 1
Preparation of Polyether Carbonate Polyol PECP-1 Having a High
Proportion of Primary OH Groups
Step (ii)
[0205] A 2 liter stainless steel pressure reactor was initially
charged with 660 g of the polyether carbonate polyol precursor A
and 0.442 g of DMC catalyst under nitrogen, and heated to
130.degree. C. Stripping was accomplished by introducing nitrogen
into the reaction mixture at 130.degree. C. for a period of 30 min
and simultaneously applying a reduced pressure (in absolute terms),
such that a reduced pressure of 0.1 bar (absolute) was established
in the stainless steel pressure reactor. Subsequently, nitrogen was
used to establish a reactor pressure of 2.8 bar (absolute).
[0206] Step (ii-1): Then, at 130.degree. C., a mixture of 39.6 g of
ethylene oxide and 26.4 g of propylene oxide was first metered into
the reactor while stirring (800 rpm) within 15 min
[0207] Step (ii-2): At 130.degree. C., a mixture of 52.8 g of
ethylene oxide and 13.2 g of propylene oxide was then metered into
the reactor while stirring (800 rpm) within 15 min
Step (iii):
[0208] Finally, another 92.4 g of ethylene oxide were metered into
the stainless steel pressure reactor at 130.degree. C. and 800 rpm
within 30 min, and the pressure in the reactor at the end of the
metered addition was 4.7 bar (absolute). After further reaction for
45 min, volatile constituents were distilled off under reduced
pressure at 50 mbar (absolute) and 90.degree. C. for 30 minutes and
then the reaction mixture was cooled to room temperature.
Product Properties:
[0209] OH number: 41.3 mg KOH/g
[0210] Polydispersity: 1.14
[0211] Primary OH groups: 65%
Comparative Example 2
Preparation of Polyether Polyol PET-1 Having a High Proportion of
Primary OH Groups
[0212] Comparative example 2 was conducted in an analogous manner
to example 1, except that polyether carbonate polyol precursor A
was exchanged for polyether polyol precursor A.
Product Properties:
[0213] OH number: 42.8 mg KOH/g
[0214] Polydispersity: 1.22
[0215] Primary OH: 63%
Example 3
Preparation of Polyether Carbonate Polyol PECP-2 Having a High
Proportion of Primary OH Groups in the Presence of Cyclic Propylene
Carbonate as Solvent
Step (ii)
[0216] A 2 liter stainless steel pressure reactor was initially
charged with 400 g of the polyether carbonate polyol precursor A
under nitrogen, and heated to 130.degree. C. Stripping was
accomplished by introducing nitrogen into the reaction mixture at
130.degree. C. for a period of 30 min and simultaneously applying a
reduced pressure (in absolute terms), such that a reduced pressure
of 0.1 bar (absolute) was established in the stainless steel
pressure reactor. Subsequently, 26 g of cyclic propylene carbonate
were added. Subsequently, the pressure in the stainless steel
pressure reactor was reduced to 0.1 bar (absolute) and then it was
charged with 3.0 bar (absolute) of nitrogen, and this sequence of
evacuation and pressurization was repeated twice more. Then
nitrogen was used to establish a reactor pressure of 3.0 bar
(absolute).
[0217] Step (ii-1): At 130.degree. C., a mixture of 22.3 g of
ethylene oxide and 14.9 g of propylene oxide was then first metered
into the reactor while stirring (800 rpm) within 10 min.
[0218] Step (ii-2): At 130.degree. C., a mixture of 29.7 g of
ethylene oxide and 7.4 g of propylene oxide was then metered into
the reactor while stirring (800 rpm) within 10 min.
Step (iii):
[0219] Finally, another 52.0 g of ethylene oxide were metered into
the stainless steel pressure reactor at 130.degree. C. and 800 rpm
within 25 min, and the pressure in the reactor at the end of the
metered addition was 4.2 bar (absolute). After further reaction for
30 min, volatile constituents and solvent were distilled off under
reduced pressure at 50 mbar (absolute) and 130.degree. C. for 60
minutes and then the reaction mixture was cooled to room
temperature.
Product Properties:
[0220] OH number: 42.1 mg KOH/g
[0221] Polydispersity: 1.11
[0222] Primary OH: 59%
Comparative Example 4
Preparation of Polyether Polyol PET-2 Having a High Proportion of
Primary OH Groups in the Presence of Cyclic Propylene Carbonate as
Solvent
[0223] Comparative example 4 was conducted in an analogous manner
to example 3, except that polyether carbonate polyol precursor A
was exchanged for polyether polyol precursor A.
Product Properties:
[0224] OH number: 41.0 mg KOH/g
[0225] Polydispersity: 1.20
[0226] Primary OH: 63%
CONCLUSION
[0227] A comparison of example 1 with comparative example 2 and of
example 3 with comparative example 4 shows that use of a polyether
carbonate polyol precursor gave narrower molar mass distributions
(lower polydispersities) than use of corresponding polyether polyol
precursors.
Example 5
Preparation of Polyether Carbonate Polyol PECP-3 Having Primary OH
Groups in the Presence of Cyclic Propylene Carbonate as Solvent
Step (ii)
[0228] A 2 liter stainless steel pressure reactor was initially
charged with 660 g of the polyether carbonate polyol precursor B
under nitrogen, and heated to 130.degree. C. Stripping was
accomplished by introducing nitrogen into the reaction mixture at
130.degree. C. for a period of 30 min and simultaneously applying a
reduced pressure (in absolute terms), such that a reduced pressure
of 0.1 bar (absolute) was established in the stainless steel
pressure reactor. Subsequently, 40 g of cyclic propylene carbonate
were added. Subsequently, the pressure in the stainless steel
pressure reactor was reduced to 0.1 bar (absolute) and then it was
charged with 3.0 bar (absolute) of nitrogen, and this sequence of
evacuation and pressurization was repeated twice more. Then
nitrogen was used to establish a reactor pressure of 3.0 bar
(absolute).
[0229] Step (ii-1): Then, at 130.degree. C., a mixture of 25.5 g of
ethylene oxide and 17.0 g of propylene oxide was first metered into
the reactor while stirring (800 rpm) within 15 min.
[0230] Step (ii-2): At 130.degree. C., a mixture of 33.9 g of
ethylene oxide and 8.5 g of propylene oxide was then metered into
the reactor while stirring (800 rpm) within 15 min.
Step (iii):
[0231] Finally, another 59.4 g of ethylene oxide were metered into
the stainless steel pressure reactor at 130.degree. C. and 800 rpm
within 30 min, and the pressure in the reactor at the end of the
metered addition was 4.6 bar (absolute). After further reaction for
45 min, volatile constituents and solvent were distilled off under
reduced pressure at 50 mbar (absolute) and 130.degree. C. for 60
minutes and then the reaction mixture was cooled to room
temperature.
Product Properties:
[0232] OH number: 43.2 mg KOH/g
[0233] Polydispersity: 1.26
[0234] Primary OH: 51%
C. Production of Flexible Polyurethane Foams
C.1 Materials and Abbreviations Used
[0235] The materials and abbreviations used have the following
meanings and sources: [0236] Tegostab.RTM. B 8681: formulation of
organo-modified polysiloxanes, from Evonik Goldschmidt [0237]
Tegostab.RTM. B 8715LF: formulation of organo-modified
polysiloxanes, from Evonik Goldschmidt [0238] PET-3: Polyether
polyol having an OH number of about 28 mg KOH/g, prepared by means
of KOH-catalyzed addition of propylene oxide and ethylene oxide in
a weight ratio of 85 to 15 using a mixture of glycerol and sorbitol
as starter compounds, having about 85 mol % of primary OH groups
and containing 8.6% by weight of filler (copolymer essentially
formed from styrene and acrylonitrile). [0239] PET-4: Polyether
polyol having an OH number of about 28 mg KOH/g, prepared by means
of KOH-catalyzed addition of propylene oxide and ethylene oxide in
a weight ratio of 85 to 15 using glycerol as starter compound,
having about 85 mol % of primary OH groups. [0240] PET-5: Polyether
polyol having an OH number of 37 mg KOH/g, prepared by means of
KOH-catalyzed addition of propylene oxide and ethylene oxide in a
weight ratio of 27 to 73 using glycerol as starter compound. [0241]
Amine 1: amine catalyst (diazabicyclo[2.2.2]octane, 33% by weight
in dipropylene glycol). [0242] Amine 2: amine catalyst
(bis(dimethylaminoethyl) ether, 70% by weight in dipropylene
glycol). [0243] Amine 3:
N,N-bis(3-dimethylaminopropyl)-N-isopropanolamine. [0244] Amine 4:
amine catalyst, Dabco.RTM. NE 300, from Air Products, Hamburg,
Germany. Urea solution (50% H.sub.2O): solution of urea in water
(50% by weight). [0245] Sn cat.: tin(II) octoate [0246] MDI 1:
mixture containing 57% by weight of diphenylmethane
4,4'-diisocyanate, 25% by weight of diphenylmethane
2,4'-diisocyanate and 18% by weight of polyphenylpolymethylene
polyisocyanate ("multiring MDI"), having an NCO content of 32.5% by
weight. [0247] TDI 1: mixture of 80% by weight of tolylene
2,4-diisocyanate and 20% by weight of tolylene
2,6-diisocyanate.
C.2 Flexible Slabstock Polyurethane Foams
[0248] In the manner of processing by the one-stage process, which
is customary for the production of polyurethane foams, the
feedstocks listed in the examples in table 1 below were reacted
with one another.
[0249] The resultant flexible slabstock polyurethane foams were
subjected to a visual assessment. The classification of the
flexible slabstock polyurethane foams ("Foam assessment") was made
on a scale of coarse--average--fine. A "coarse" classification here
means that the foam has fewer than about 5 cells per cm. An
"average" classification means that the foam has more than about 5
cells per cm and fewer than about 12 cells per cm, and a "fine"
classification means that the foam has more than about 12 cells per
cm.
[0250] The classification of the foam quality of the flexible
slabstock polyurethane foams in terms of cell structure was made on
a scale of poor--average--good. A "poor" classification here means
that the foam does not have a homogeneous cell structure and/or has
visible defects. An "average" classification means that the foam
has a mainly homogeneous cell structure with only few visible
defects and a "good" classification means that the foam has a
homogeneous cell structure with no visible defects.
TABLE-US-00001 TABLE 1 Production and assessment of the flexible
slabstock polyurethane foams Example 6*.sup.) (blank test) 7
8*.sup.) 9 10*.sup.) 11 Component A: PET-3 [pts. by wt.] 96.55
77.24 77.24 77.24 77.24 77.24 PECP-1 (from ex. 1) [pts. by wt.]
19.31 -- -- -- -- PET-1 (from comp. ex. 2) [pts. by wt.] -- 19.31
-- -- -- PECP-2 (from ex. 3) [pts. by wt.] -- -- 19.31 -- -- PET-2
(from comp. ex. 4) [pts. by wt.] -- -- -- 19.31 -- PECP-3 (from ex.
5) [pts. by wt.] -- -- -- -- 19.31 Water (added) [pts. by wt.] 1.82
1.82 1.82 1.82 1.82 1.82 Tegostab .RTM. B 8681 [pts. by wt.] 0.39
0.39 0.39 0.39 0.39 0.39 Amine 1 [pts. by wt.] 0.16 0.16 0.16 0.16
0.16 0.16 Amine 2 [pts. by wt.] 0.05 0.05 0.05 0.05 0.05 0.05 Urea
solution (50% H.sub.2O): [pts. by wt.] 0.39 0.39 0.39 0.39 0.39
0.39 Diethanolamine [pts. by wt.] 0.48 0.48 0.48 0.48 0.48 0.48 Sn
cat. [pts. by wt.] 0.16 0.16 0.16 0.16 0.16 0.16 Component B: TDI 1
[MR] 29.0 31.1 31.1 31.1 31.1 31.1 Index 110 110 110 110 110 110
Results: Cream time [s] 10 10 10 10 10 11 Rise time [s] 90 85
collapsed 95 collapsed 90 Foam assessment fine fine fine fine Cell
structure good good good good Apparent density [kg/m.sup.3] 43.5
44.1 42.9 41.5 Tensile strength [kPa] 77 82 75 90 Elongation at
break [%] 96 86 99 114 Indentation hardness [kPa] 4.6 5.1 4.3 4.0
CS 90%/22 h/70.degree. C. [%] 4.2 8.3 5.0 4.8 Abbreviations:
*.sup.)= comparative example, [pts. by wt.] = parts by weight; [MR]
= weight ratio of component A to component B at the given index and
based on 100 parts by weight of component A.
[0251] The inventive flexible slabstock polyurethane foam (example
7), in which the polyether carbonate polyol PECP-1 from example 1
was processed, had good foamability with a standard HR foam
formulation. In contrast, it was not possible to produce a suitable
foam using the polyether polyol PET-1 (comparative example 8). The
foam collapsed.
[0252] The inventive flexible slabstock polyurethane foam (example
9), in which the polyether carbonate polyol PECP-2 from example 3
was processed, had good foamability with a standard HR foam
formulation. In contrast, it was not possible to produce a suitable
foam using the polyether polyol PET-2 (comparative example 10). The
foam collapsed.
[0253] Example 11, using the polyether carbonate polyol PECP-3 from
example 5, gave a flexible slabstock foam having a very good level
of properties with impeccable processibility.
[0254] The processibility of the inventive polyether carbonate
polyols to give flexible slabstock foams (examples 7, 9 and 11) is
at a good level: On partial exchange of the polyether polyol PET-3
for a polyether carbonate polyol (PECP-1, PECP-2 or PECP-3), there
is no need to adjust the further constituents of the polyol
formulation (additives) in terms of type and/or amount in order to
achieve impeccable processibility, and the mechanical properties of
the resulting flexible slabstock foams (examples 7, 9 and 11) have
a level comparable to the blank test (comparative example 6).
C.3 Flexible Molded Polyurethane Foams
[0255] In the manner of processing by the one-stage process, which
is customary for the production of flexible molded polyurethane
foams, the feedstocks listed in the examples in table 2 below were
reacted with one another. The reaction mixture was introduced into
a metal mold of volume 9.7 L which had been heated to 60.degree.
C., and demolded after 5 min. The amount of the raw materials used
was chosen so as to result in a calculated molding density of about
57 kg/m3. Table 2 states the molding density actually obtained,
which was determined to DIN EN ISO 3386-1-98.
TABLE-US-00002 TABLE 2 Production and assessment of the flexible
molded polyurethane foams 12*.sup.) (blank test) 13 14*.sup.) 15
Component A PET-4 [pts. by 92.24 73.32 73.32 73.32 wt.] PET-5 [pts.
by 2.37 2.37 2.37 2.37 wt.] PECP-1 (from ex. 1) [pts. by 18.92 wt.]
PET-1 (from comp. [pts. by 18.92 ex. 2) wt.] PECP-3 (from ex. 5)
[pts. by 18.92 wt.] Water (added) [pts. by 3.03 3.03 3.03 3.03 wt.]
Diethanolamine [pts. by 0.95 0.95 0.95 0.95 wt.] Tegostab B 8715 LF
[pts. by 0.95 0.95 0.95 0.95 wt.] Amine 3 [pts. by 0.39 0.39 0.39
0.39 wt.] Amine 4 [pts. by 0.09 0.09 0.09 0.09 wt.] Component B:
MDI 1 [MR] 56.19 56.94 56.94 57.16 Index 100 100 100 100 Results:
Apparent density [kg/m.sup.3] 57.3 56.7 collapsed 56.3 Indentation
hardness [kPa] 8.10 7.16 7.85 Tensile strength [kPa] 148 150 159
Elongation at break [%] 90 102 103 CS 50%/22 h/70.degree. C. [%]
5.9 6.8 7.1 CS 75%/22 h/70.degree. C. [%] 7.8 8.8 8.7
Abbreviations: *.sup.) = comparative example, pts. by wt. = parts
by weight; MR = weight ratio of component A to component B at the
given index and based on 100 parts by weight of component A.
[0256] The inventive polyether carbonate polyols can be processed
without any problem to give molded flexible polyurethane foams, in
contrast to comparative example 14 which led to collapse when
processed to give a molded flexible foam. The inventive flexible
molded polyurethane foams from examples 13 and 15 have a good level
of properties.
[0257] The processibility of the inventive polyether carbonate
polyols to give flexible molded polyurethane foams (examples 13 and
15) is at a good level: On partial exchange of polyether polyol
(here: mixture of PET-4 and PET-5) for a polyether carbonate polyol
(PECP-1 or PECP-3), there is no need to adjust the further
constituents of the polyol formulation (additives) in terms of type
and/or amount in order to achieve impeccable processibility, and
the mechanical properties of the resulting flexible molded foams
(examples 13 and 15) have a level comparable to the blank test
(comparative example 12).
* * * * *