Note: Descriptions are shown in the official language in which they were submitted.
2IS2240
HOECHST AKTIENGESELLSCHAFT HOE 94/F 169 Dr. KI
Description
Alkoxylation product mixtures having a narrow alkoxyl
distribution
The invention relates to alkoxylation product mixtures
having a narrow alkoxyl distribution, and also to a
process for the preparation of the~e alkoxylation product
mixtures and to their use.
Alkoxylates have great importance, for example as inter-
mediates for derivatizations and as nonionic components
in industrial and cosmetic detergents and cleaners. They
are additionally employed in a multiplicity of applica-
tion areas as emulsifiers, dispersants and the like. In
these areas, the alkoxylates desired are frequently those
which have a narrow distribution of the alkoxylation
homologs.
The still unpublished German Patent Application with the
reference P 4341576.8 describes ethoxylates having a
narrow homolog distribution. A process for the ethoxyla-
tion of compounds cont~;n;ng active hydrogen atoms in the
presence of specific alkaline earth metal salts of alkyl-
or alkenylsuccinic acid monoesters as catalysts is
additionally described.
EP-A-0 133 715 describes alkoxylation product mixtures
which are obtained by reaction of an organic compound
containing at least one active hydrogen atom with an
epoxide, such as ethylene oxide or propylene oxide, the
product mixture cont~;n;ng an alkoxylation unit which i~
20-40% by weight of the mixture.
It has been shown, however, that the alkoxylation product
mixtures known from the prior art only have limited
biodegradability. With regard to increased environmental
con~ciousne~s, however, particular attention is being
directed even at the characteristic of biodegradability
2152240
.
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in the case of detergents and cleaners.
The object was thus to make available alkoxylation
product mixtures which are distinguished by good
biodegradability.
It has been shown that this object can be achieved by the
provision of alkoxylation product mixtures having a
narrow alkoxyl distribution.
The invention relate~ to alkoxylation product mixtures of
the formula I having a narrow alkoxyl distribution
CH~
R - (CH2 - CH2 - 0)~ - (CH - CH2 ~ )r H (I)
where R is the radical of an organic compound containing
at least one active hydrogen atom, m is an integer from
1 up to the number of active hydrogen atoms in the
organic compound, x and y in each case are the average
molar number of ethylene oxide or propylene oxide units
and independently of one another are an integer from 2 to
10 and the individual alkoxylation units of the alkoxyla-
tion product mixture in each case at most have a degree
of alkoxylation of 18% by weight.
Formula I, m is preferably a number from 1 to 3 and
particularly preferably equal to 1. The values x and y in
formula I are, independently of one another, preferably
a number from 2 to 6, and y is particularly preferably a
number from 2 to 4.
Preferred alkoxylation product mixtures of the formula I
are those in which m = 1 and x and y independently of one
another are an integer from 2 to 6.
Particularly preferred alkoxylation product mixtures of
the formula I are those in which m = 1, x and y are
independent of one another and x is a number from 2 to 6
2l522~ o
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-- 3
and y is a number from 2 to 4.
The radical R in formula I is derived from organic
compounds having at least one active hydrogen atom, for
example from compounds containing hydroxyl groups, amine
compounds and acid compounds such as fatty acids.
Preferably, the radical R is derived from compounds
cont~;n;ng hydroxyl groups, for example from alcohols,
amino alcohols, perfluoroalkyl alcohols, glycols, glycol
monoethers, phenols or kresols, alcohols being particu-
larly preferred. They can originate from a native sourceor from synthetic processes, and be straight-chain or
branched, saturated or unsaturated and mono- or poly-
valent, for example oxo alcohols or fatty alcohols.
In particular, monovalent, straight-chain or branched,
saturated or unsaturated C8-C18-alcohols or mixtures
thereof are employed, for example mixtures of C12 and
C14-alcohol (C12~14). Specific examples of the particu-
larly preferred alcohols which may be mentioned are:
non~nol, isononyl alcohol, decanol, undecanol, isounde-
canol, lauryl alcohol, isotridecyl alcohol, stearylalcohol, coconut fatty alcohol and mixtures thereof, and
also 2-ethylhexanol, 2-hexyldecanol and 2-octyldecanol.
In formula I, R is consequently particularly preferably
a monovalent, ~traight-chain or branched, saturated or
unsaturated C8-C18-alkoxy group or mixtures thereof.
Preferred alkoxylation products of the formula I are
therefore those in which m = 1, x and y independently of
one another are a number from 2 to 6 and R is a mono-
valent, straight-chain or branched, saturated or unsatu-
rated C8-C18-alkoxy group or mixtures thereof.
Particularly preferred alkoxylation products of the
formula I are those in which m = 1, x and y are indepen-
dent of one another, x is a number from 2 to 6 and y is
a number from 2 to 4 and R is a monovalent, straight-
chain or branched, saturated or unsaturated C8-C18-alkoxy
group or mixtures thereof.
- - 21 ~2240
The invention addltlonally relates to a process for the
preparatlon of alkoxylatlon product mlxtures accordlng to the
formula I comprlslng the process steps
- reactlon of an organlc compound contalning at least
one actlve hydrogen atom wlth ethylene oxlde ln a molar ratlo
of 2 to 10 mol of ethylene oxlde per mole of actlve hydrogen
ln the compound to be ethoxylated ln the presence of at least
one alkallne earth metal salt of the alkyl- or alkenylsucclnlc
acid monoester of the formulae (II) and ~III) below as
catalyst
R3 - CH - COO - (CH2CH2O)n-R (M2+)
¦ (II)
CH2 COO -2
_ __
H2 COO - ( CH2CH2o ) n~R4 ( M2+ )
¦ (III)
R3 CH - COO - 2
where
R3 8 30 alkyl or C8 to C30-alkenyl
n ls an lnteger from 0 to 6,
R4 ls Cl to C18-alkyl or C3 to C18-alkenyl or hydrogen
lf n = 1 or ~ 1,
M ls Ba, Ca or Sr and
z ls a number from 0.9 to 1.8,
- then addltlon of a base to the ethoxylate product
mlxture obtalned and addltlon of propylene oxlde.
23221-5372
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4a
The reactlon of the organic compound containlng at
lest one actlve hydrogen atom wlth ethylene oxlde ln the
presence of at least one alkallne earth metal salt of the
alkyl- or alkenylsucclnic acid hemiester is customarily
carried out at a temperature from 60 to 200C, preferably 100
to 180C, and a pressure of approximately 0.5 to 6 bar, the
ethylene oxide being metered in ln portlons or
23221-5372
2152240
continuously. The amount of ethylene oxide added is 2 to
10 mol, preferably 2 to 8 mol and in particular 2 to
6 mol, per mole of active hydrogen in the compound to be
ethoxylated. The ethoxylation product mixture obtained
can in general be reacted again without prior separation
of the catalyst.
The alkaline earth metal salts of alkyl- and/or alkenyl-
succinic acid hemiesters to be used (in this case these
are positional isomers which in general are present in
the mixture) are known and are commercially available,
for example as ~HOSTACOR (~ = registered trademark of
Hoechst). In the formulae II and III, R3 is preferably a
Cg to C20-alkyl or a Cg to C20-alkenyl, n i~ preferably a
number from O to 3, Rl is preferably a C1 to Cl2-alkyl or
a C3 to Cl2-alkenyl and can preferably also be the hydro-
gen atom if n = 1 or ~ 1 and z is preferably a number
from 1 to 1.3 and particularly preferably 1. For reasons
of expediency, M is preferably Ca. For z c 1, besides M
protons can additionally be present as further counter-
ions. The alkenyl groups preferably have 1 to 3 doublebonds. The alkyl and alkenyl groups can be straight or
branched. Alkyl and alkenyl can also be present in the
form of mixtures, for example in the form of a mixture of
Cl2 and Cl4-alkyl (Cl2/14-alkyl) or C12 and C14 alkenyl
(Cl2/l4-alkenyl) or of Cl2 and Cl4-alkyl and -alkenyl
groups. Of the alkaline earth metal salts to be used of
the succinic acid hemiester substituted by an alkyl or an
alkenyl group, those substituted by an alkenyl group are
preferred, that is R3 in the formulae (II) and (III) is
preferably one of the alkenyl group~ mentioned. The
radical R4, on the other hand, is preferably one of the
alkyl groups mentioned. Examples of alkyl and alkenyl
radicals are thus methyl, propyl, butyl, isobutyl, octyl,
octenyl, decyl, decenyl, dodecyl (lauryl), dodecenyl,
oleyl, octadecadienyl, octadecatrienyl and tallow fatty
alkyl.
It was found that a still higher activity with respect to
. 2l522qo
catalytic activity and narrow homolog distribution is
achieved if the ethoxylation is carried out in the
presence of at least one succinic acid monoester salt of
the formulae (II) and (III), of which 10 to 70%, prefer-
ably 30 to 60%, of its titratable alkalinity has beenneutralized by an inorganic acid which forms poorly
water-soluble salts with the cations Ba, Ca and Sr.
Preferred mineral acids are sulfuric acid (H2S04) and
sulfurous acid (H2S03) as well as phosphoric acid (H3P04)
and phosphorous acid (H3P03).
The amount of the alkaline earth metal salt of the alkyl-
or alkenylsuccinic acid hemiester to be employed in the
ethoxylation can vary within wide limits and is in
general 0.1 to 5% by weight, preferably 0.5 to 3% by
weight, based on the weight of the organic compound
having at least one active hydrogen atom to be
alkoxylated. The catalyst is added to the compound to be
alkoxylated in the amount indicated. It can also be
produced in situ, for example by first adding to the
compound to be alkoxylated a defined amount of a barium,
calcium or strontium oxide, carbonate or hydroxide, the
hydroxides being preferred, and adding the stoichiometric
amount of substituted succinic anhydride compound
adjusted to this, resulting from the formulae (II) and
(III), and then drying, optionally under reduced pres-
sure, whereupon the reaction is begun with the ethoxyla-
tion. The in-situ variant can also include the part
neutralization described.
The alkaline earth metal salts of the alkyl- or alkenyl-
succinic acid hemiesters have a high catalytic activityand lead in a relatively short reaction time to a vir-
tually complete conversion and to a high yield. The
ethoxylate consequently has a narrow homolog distribution
and only a small content of the starting compound to be
ethoxylated.
The ethoxylated product mixture obtained after the
21S224~
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ethoxylation i8 treated, for further catalysis, with a
base and the mixture is then optionally dried. Prefer-
ably, the ethoxylate product mixture is treated with an
aqueous alkali metal hydroxide solution or an alkali
metal alkoxide as a base. The aqueous alkali metal
hydroxide solution employed is preferably a sodium
hydroxide solution. Alkali metal alkoxides of
C1-C4-alcohols, preferably methanol or ethanol, are
furthermore used. Drying is customarily carried out at a
temperature of 70 - 150C, preferably 80 - 120C, and
under a reduced pressure of 10 - 100 mbar, preferably
10 - 30 mbar.
The amount of the base employed is proportioned such that
an alkali number of 1 - 5 results in the crude final
product.
The propylene oxide is added to the optionally dried
ethoxylation product mixture. This addition is custo-
marily carried out over a period of 1 - 10 h, at a
temperature of 100 - 150C, preferably 110 - 140C, the
propylene oxide being metered in in portions or con-
tinuously. The amount of propylene oxide is in general 2
to 10 mol, preferably 2 to 6 mol and in particular 2 to
4 mol, per mole of active hydrogen in the compound to be
alkoxylated. If appropriate, the alkoxylation product
mixture is then neutralized with a Cl-C10-carboxylic acid,
straight-chain, aliphatic C1-C3-carboxylic acids and
branched, aliphatic CB-ClO-carboxylic acids preferably
being used in this case. The alkoxylation product mixture
obtained can in general be further used without prior
separation of the catalysts.
The alkoxylation product mixtures according to the
invention have a narrow homolog distribution and are
distinguished by a particularly good biodegradability. In
their capacity as low-foaming surfactants, they can be
employed in cleaners, for example liquid detergentsl
liquid cleaners, machine dishwashing liquids/powders ana';
bottle cleaners. They can also be used as dispersants or
21522~0
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wetting agents.
The invention is now illustrated in greater detail by
examples.
The homolog distribution of the alcohol alkoxylates
obtained in the examples was determined by means of
capillary gas chromatography after prior derivatization
(silylation of the OH end groups of the alcohol block
alkoxylates using (CH3)3SiCl). As a measure of the homo-
log distribution, the so-called Q value according to the
equation Q = n* x p2 is given, in which n* is the average
number of ethylene oxide and propylene oxide molecules
added to the organic starting compound containing at
least one active hydrogen atom (mean degree of alkoxyla-
tion) and p is the percentage by weight of the most
highly occurring alkoxylation homologs in % by weight.
This Q value, as is known, is in particular a good
st~n~rd if these are alkoxylates having an essentially
identical average degree of alkoxylation. Higher values
of Q indicate a more selective alkylation and an alkoxy-
late having a narrower homolog distribution.
The biodegradability was determined in the modified Sturmtest in accordance with OECD guideline 301B, in which the
substances were tested over a period of 29 days on an
unadapted activated sludge.
Examples
Preparation of c12-cl4-fattY alcohol-ethylene
oxide/propylene oxide block alkoxylates
Example 1
1st stage:
194 g (1.00 mol) of a C12/14-alcohol mixture were
initially introduced into a stirable pressure reactor.
After the customary flll~h;ng of the reaction space with
nitrogen, the mixture was heated to 90C and stirred
under reduced pressure for 1 hour in order to lower the
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g
water content to ~0.10% by weight. 2.9 g of the catalyst
1 were then added and a total of 251 g of ethylene oxide
(5.7 mol) were metered in at 150 - 160C in a period of
5 hours.
To react the epoxide completely, the mixture was addi-
tionally stirred at 150 - 160C for 1 hour.
2nd stage:
2.4 g of a 50% strength aqueous NaOH solution were added
to the C12/14-alcohol ethoxylate pre~ent in the reactor
from the 1st ~tage and the mixture was then dried at 90C
for 2 hours under a reduced pressure of 20 mbar.
A total of 232 g of propylene oxide (4.0 mol) were then
metered in at 120 - 130C in a period of 5 hours.
To react the epoxide completely, the mixture was addi-
tionally stirred at 135C for 1 hour.
It was then neutralized using isononanoic acid.
Catalygt 1 i8 a compound of the formula (II), where
R3 is iso-Cl2-alkenyl,
R4 is isobutyl,
n is O,
M is Ca and
z is 1
and this alkenylsuccinic acid hemiester calcium salt was
partially neutralized using 0.4 times the stoichiometric
amount of H2SO4 neces~ary for neutralization of the
alkalinity (as a 25% strength by weight aqueous
solution).
At 20C, the final product is a ~lightly turbid, low
viscosity liquid with a turbidity point of 32C (measured
in a 1% strength aqueous solution according to
DIN 53917).
The pH of a 1% ~trength aqueous solution is 6.6; an OH
number (corr.) of 89 i~ obtained. The Q value is 2450.
Table 1 contains the homolog distribution of the alcohol
alkoxylates prepared.
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In testing the biodegradability, the alcohol alkoxylates
prepared attained the threshold value required in the
context of the 29-day experimental period of a degree of
degradation greater than or equal to 60% by weight within
10 days after exceeding the 10% by weight limit (= start
of the degradation phase) and were therefore classified
as easily biodegradable. At a test concentration of
7 mg/l, the alcohol alkoxylates were degraded to 100% by
weight after 22 days. Table 2 contains the data for the
biodegradability of the alcohol alkoxylates.
Table 1: Homolog distribution of the fatty alcohol-
ethylene oxide (EO)/propylene oxide (PO) block
alkoxylate
EO+PO 1 2 3 4 5 6 7 8 9 10 11
15 number
~ by 1.8 2.3 2.8 3.9 6.4 10.5 15.1 17.5 17.1 13.3 9.2
weight
Table 2: Biodegradability of the fatty alcohol-EO/PO
block alkoxylate
Test concentration 7 ~mg/L]
Biodegradation after 6 d 35 ~%]
after 14 d 86 ~%]
after 22 d 100 ~%]
after 29 d 100 ~%]
Example 2
l~t stage:
194 g (1.00 mol) of a Cl2/l4-alcohol mixture was initially
introduced into a stirable pressure reactor. After the
customary flu~hing of the reaction ~pace with nitrogen,
the mixture was heated to 90C and stirred under reduced
pressure for 1 hour in order to lower the water content
to ~ 0.10% by weight.
2.9 g of the catalyst 2 were then added and a total of
97 g of ethylene oxide (2.2 mol) were metered in at
150 - 160C in a period of 3 hours. To react the epoxide
completely, it was additionally stirred at 150 - 160C
2152290
for 1 hour.
2nd stage:
2.0 g of a 50% strength aqueous NaOH solution were added
to the C12/14-alcohol ethoxylate present in the reactor
from the 1st stage and the mixture was then dried at 90C
for 2 hours under a reduced pres~ure of 20 mbar.
A total of 232 g of propylene oxide (4.0 mol) were then
metered in at 120 - 130C in a period of 5 hours. To
react the epoxide completely, the mixture was addi-
tionally stirred at 135C for 1 hour.It was then neutralized with isononanoic acid.
At 20C, the final product is a slightly turbid, low-
viscosity liquid having a turbidity point of 27C in
butyldiglycol/water (measured according to DIN 53917).
The pH of a 1% strength aqueous solution is 7.1; an OH
number (corr.) of 112 is obtained. The Q value is 1220.
Table 3 contains the homolog distribution of the alcohol
alkoxylates prepared.
In testing the biodegradability, the alcohol alkoxylates
prepared attained the threshold value of a degree of
degradation greater than or equal to 60% by weight
required in the context of the 29-day experimental period
within 10 days after exceeding the 10% by weight limit (=
start of the degradation phase) and were therefore
classified as easily biodegradable. At a test concentra-
tion of 7 mg/l, the alcohol alkoxylates were degraded to
100% by weight after 29 days. Table 4 contains the data
for the biodegradability of the alcohol alkoxylates.
Catalyst 2 is a compound of the formula (II), where
R3 is iso-C12-alkenyl,
R4 i8 c12/14-alkyl,
n is O,
M is Ca and
z is 1
and this alkenylsuccinic acid hemiester calcium Ralt was
21S2240
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partially neutralized using 0.4 times the stoichiometric
amount of H2S04 necessary for the neutralization of the
alkalinity (as a 25% strength by weight solution).
Table 3: Homolog distribution of the fatty alcohol-
ethylene oxide (E0)/propylene oxide (P0) block
alkoxylate
EOIPO 1 2 3 4 5 6 7 8 9 10 11
number
% by 7.0 9.5 11.2 11.8 13.6 14.0 13.2 9.4 6.1 2.7 1.7
1 0 weight
Table 2: Biodegradability of the fatty alcohol-E0/P0
block alkoxylate
Test concentration 7 [mg/L]
Biodegradation after 6 d 29 [%]
after 14 d 64 [%]
after 22 d 90 [%]
after 29 d 100 [%]
