IMPROVED ALKOXYLATION PROCESS
[0001] The present invention relates to an improved alkoxylation process, more
5 particularly to a process for preparing alkoxylated compounds, in particular high molar mass
alkoxylated compounds, and more particularly high molar mass alkoxylated compounds
comprising a fatty chain.
[0002] Alkoxylated compounds (also referred to as alkoxylates in the remainder of the
disclosure), and in particular fatty-chain alkoxylates, are compounds that are used ever
10 more frequently in particular as additives, adjuvants, chemical intermediates, and
surfactants (nonionic surfactants), and others, in various fields of applications, such as for
example in the general chemical industry, in the pharmaceuticals, cosmetics, foodprocessing, phytosanitary and textile industries, in the cleaning, ore, fertilizer, petroleum
and gas extraction, road construction, coating, adhesive, sealant, lubrication and paper
15 industries, and others, to mention just the main fields of application.
[0003] For these fields of application, the alkoxylated compounds must generally and
most often have high purities, that is to say contain the smallest possible amounts of
impurities, and in particular of undesirable products, and more particularly those generated
during the synthesis of said alkoxylated compounds.
20 [0004] The reaction of polymerization of alkylene oxides, by ring opening, under specific
operating conditions, in particular in terms of nature of the catalysts used, reaction
temperatures and pressures, have already been widely studied and industrialized on a large
scale.
[0005] However, the synthesis of alkoxylated compounds, in particular high molecular
25 weight alkoxylates and more particularly high molecular weight alkoxylates comprising a
fatty chain, is often still delicate to carry out, in particular when the desire is to obtain highpurity products, that is to say those with the smallest possible amounts of by-products, with
good production yields.
[0006] A few rare works mention the formation of impurities, such as for example in the
30 patent EP1062263 B1, which teaches that the synthesis of propylene oxide polyether
polyols, as well as polyurethane foams prepared from them, exhibit unpleasant odors and
that the compounds responsible for these bad odors might be aldehydes, either as such or
in latent form, and also cyclic ethers formed during the propoxylation reaction.
[0007] This patent also states that the elimination of the unpleasant odors is carried out
35 by neutralization of the product of the propoxylation reaction with an acid of pKa of less than
— 2 —
5, at a temperature of between 80°C and 130°C, and then by contact with water, at a
temperature of between 80°C and 130°C. The recovery of the final product, devoid of bad
odors, comprises removal of the water and stripping of the propionaldehyde formed, or
derivatives thereof.
5 [0008] There remains today a need for a process for preparing alkoxylated compounds,
in particular high molar mass alkoxylated compounds, and more particularly high molar
mass alkoxylated compounds comprising a fatty chain and satisfying the increasingly
stringent purity criteria imposed by the industries that use such molecules, in particular as
nonionic surfactants, synthesis intermediates, and others, as stated above.
10 [0009] Another objective is to propose a process for synthesizing alkoxylated compounds,
in particular high molar mass alkoxylated compounds and more particularly high molar mass
alkoxylated compounds comprising a fatty chain that are readily industrializable and
advantageously that can be readily adapted to pre-existing techniques and installations
used for the synthesis of such compounds.
15 [0010] It has now been discovered that the abovementioned objectives can be achieved,
entirely or at least in part, by virtue of the present invention which will be described in more
detail in the following description.
[0011] Thus, and according to a first aspect, the present invention relates to the process
for preparing compounds of formula (1):
20 R-(Ak-O-)nH (1),
in which:
- R represents a linear or branched hydrocarbon-based fatty chain comprising from 8 to 60
carbon atoms, optionally comprising one or more saturated or unsaturated rings, and
possibly comprising one or more oxygen atoms,
25 - Ak represents an alkylene unit with 2, 3 or 4 carbon atoms, preferably with 2 or 3 carbon
atoms, and
- n is an integer between 10 and 250, preferably between 15 and 200, more preferably
between 18 and 160, limits included,
said process comprising at least the following steps:
30 a) reacting a compound of the formula R-OH with at least one alkylene oxide, in the
presence of a catalyst,
b) treating the reaction medium with an acid having a pKa of less than or equal to 3.5, and
c) recovering the compound of the formula R-(Ak-O-)nH by treatment of the thus-neutralized
reaction medium.
— 3 —
[0012] As indicated above, within the meaning of the present invention, fatty chain R
(present in the compound of formula (1) and in the compound of the formula R-OH) is
understood to mean a hydrocarbon-based chain comprising from 8 to 60 carbon atoms,
preferably from 8 to 40 carbon atoms, more preferably from 10 to 30 carbon atoms, limits
5 included. This fatty chain R may comprise one or more saturated or partially or completely
unsaturated rings, said chain may also be saturated or comprise one or more unsaturations,
most often in the form of double bonds, triple bonds, or combinations of these unsaturations.
This fatty chain may be linear or branched and may comprise one or more oxygen atoms,
for example in the form of ether, alcohol, acid or ester functions, and also combinations of
10 two or more of these oxygen-bearing functions, to cite only the most common functions
bearing at least one oxygen atom. The polyalkoxylated chains are not considered to be fatty
chains within the meaning of the present invention, but the fatty chains R within the meaning
of the invention may themselves comprise one or more polyalkoxylated chains.
[0013] The compound of the formula R-OH, where R is as defined above, may be of any
15 type well known to those skilled in the art and in particular may be chosen from fatty
alcohols, fatty acids, fatty polyacids, alcohol esters, sugar esters, glycerides (mainly fatty
mono- and diesters), fatty-chain phenol derivatives, but also polyols, such as sugars, alkyl
polyglycosides, polyphenols, and also mixtures of two or more thereof, in any proportions.
Very particular preference is given to implementing the process starting from compounds
20 of the formula R-OH chosen from fatty alcohols, fatty acids, fatty polyacids, fatty-chain
phenol derivatives, polyphenols, and also mixtures of two or more thereof, in any
proportions, and more preferably from fatty alcohols, fatty acids and fatty-chain phenol
derivatives, and also mixtures of two or more thereof, in any proportions.
[0014] As examples of compounds of the formula R-OH that may advantageously be used
25 in the process of the present invention, mention may be made, in a nonlimiting manner, of
octanoic (or caprylic) acid, nonanoic (or pelargonic) acid, decanoic (or capric) acid,
undecanoic acid, undecylenic acid, dodecanoic (or lauric) acid, tetradecanoic (or myristic)
acid, hexadecanoic (or palmitic) acid, octadecanoic (or stearic) acid, 9-octadecenoic (or
oleic) acid, 9,12-octadecadienoic (or linoleic) acid, 9,12,15-octadecatrienoic (or linolenic)
30 acid, arachidic acid, arachidonic acid, behenic acid, erucic acid, octanols (in particular 1-
octanol), nonanols (in particular 1-nonanol), decanols (in particular 1-decanol), undecanols
(in particular 1-undecanol), undecenols (in particular 1-undecenol), dodecanols (in
particular 1-dodecanol), tetradecanols (in particular 1-tetradecanol), hexadecanols (in
particular 1-hexadecanol), octadecanols (in particular 1-octadecanol), oleyl alcohol, sorbitol
35 esters, sorbitan esters, sorbitol ethers, sorbitan ethers, isosorbide monoesters, isomannide
— 4 —
monoesters, isoidide monoesters, isosorbide monoethers, isomannide monoethers,
isoidide monoethers, hydroxyethyl oleate, cardanol, cardol, polyacids such as those sold
under the Pripol name by Croda, tannins, lignans, lignins and other natural polyols or polyols
derived from natural products, and also mixtures of two or more thereof in any proportions.
5 [0015] The alkylene oxide used in the process of the present invention may be of any type
well known to those skilled in the art, and is advantageously chosen from ethylene oxide,
propylene oxide and butylene oxide, and also mixtures thereof in any proportions, preferably
from ethylene oxide and propylene oxide, and also mixtures thereof in any proportions,
more preferably the alkylene oxide is ethylene oxide or propylene oxide, and
10 advantageously the alkylene oxide is ethylene oxide.
[0016] The number "n" of (Ak-O-) units present in the compound of formula (1) is between
10 and 250, preferably between 15 and 200, more preferably between 18 and 160, limits
included, as indicated above. In a very particularly preferred embodiment, the number "n"
of (Ak-O-) units present in the compound of formula (1) is between 20 and 150, better still
15 between 20 and 140, typically between 30 and 140, more specifically between 40 and 130,
for example between 50 and 100, or else between 50 and 70, limits included. It should be
understood that, when a plurality of different alkylene oxides make up the chain (Ak-O-)n,
these may be arranged randomly, in alternating fashion or else in blocks, as well as any
combinations of these various arrangements.
20 [0017] The nature and the amount of catalyst used for the alkoxylation reaction may also
vary within wide proportions, according to the alkoxylation techniques well known to those
skilled in the art. Conventionally, the catalyst is generally a basic or alkaline catalyst, such
as for example sodium hydroxide (NaOH) or potassium hydroxide (KOH). This is then
referred to as sodium hydroxide catalysis or potassium hydroxide catalysis, respectively.
25 [0018] Other types of catalysts may also be used, and in particular those currently known
to those skilled in the specialist art of alkoxylation under the name "narrow range" (narrow
distribution) catalysts, and are for example chosen from catalysts based on calcium or
based on boron-containing derivatives (for example of BF3 type and derivatives), catalysts
of hydrotalcite type, and catalysts of dimetallic cyanide ("double metal cyanide" or DMC)
30 type.
[0019] DMC catalysts are for example described in the patents US6429342, US6977236
and PL398518. Among the known and commercially available catalysts, mention may be
made of zinc hexacyanocobaltate with one or more ligands, for example the Arcol® catalyst
sold by Covestro or else the MEO-DMC® catalyst sold by Mexeo.
— 5 —
[0020] According to one embodiment of the process of the present invention, the amount
of catalyst used for the alkoxylation reaction ranges from 1 ppm to 10 000 ppm (by weight)
relative to the amount of compound of the formula R-OH, preferably from 10 ppm to
10 000 ppm (by weight).
5 [0021] According to a preferred embodiment of the invention, the process employs basic
catalysis and the catalyst used is a basic or alkaline catalyst, advantageously sodium
hydroxide (NaOH) or potassium hydroxide (KOH), or else sodium or potassium alkoxides,
more advantageously sodium hydroxide or potassium hydroxide, most frequently potassium
hydroxide. In the case of a process carried out by basic catalysis, it may be advantageous,
10 at the end of the alkoxylation reaction, to neutralize the reaction medium by adding an acid,
generally a weak organic acid, for example chosen from formic acid, acetic acid and lactic
acid, according to the conventional techniques well known to those skilled in the art.
[0022] However, it has been observed that the synthesis of high molar mass alkoxylates
from a fatty-chain compound leads most often to the formation of impurities which may
15 prove difficult to remove and troublesome or even harmful in the fields of application in
which the fatty-chain alkoxylates are used, especially when they are used as surfactants in
the cosmetics and pharmaceutical fields.
[0023] Identified in particular among these formed impurities are unsaturated ethers, for
example vinyl ethers, but also aldehydes, acetals, hemiacetals, and others, in trace form,
20 most often a few tens of ppm by weight to a few thousands of ppm by weight. Such ethers
prove difficult to remove from the reaction medium by conventional techniques. However,
for the reasons mentioned above, it is necessary in the vast majority of cases to remove
them.
[0024] A plausible explanation for the formation of these unsaturated ethers is that they
25 are by-products obtained during alkoxylation reactions involving a high number of alkoxyl
(AkO) units, by competition between the normal SN2 reaction and the parasitic E2
elimination reaction. Under normal conditions and for medium to low molecular weights, the
elimination reaction remains minor. On the other hand, when the number of alkoxylate units
is high, as is the case in the process of the present invention (n of between 10 and 250,
30 limits included), the steric hindrance becomes greater and the proportion of elimination
reaction, and hence of the formation of impurities of unsaturated ether type, increases.
[0025] The Applicant has now discovered, with this forming the subject matter of the
present invention, that it is possible to remove these impurities to a very great proportion by
applying steps b) and c) of the process of the invention, corresponding respectively to
— 6 —
treatment with an acid of pKa of less than or equal to 3.5, and then recovery of the purified
product by treatment of the neutralized reaction medium.
[0026] Without wishing to be bound by theory, this is because it has been observed that
impurities of unsaturated ether type chemically react in acidic medium to result in molecules,
5 such as aldehydes, acetals, hemiacetals and others, which can be removed much more
easily from the reaction medium, as explained below. The applicant has also discovered,
surprisingly, that only certain acids, and in particular acids of pKa of less than or equal to
3.5, enable both the chemical conversion of the unsaturated ether species generated during
the synthesis of alkoxylates of formula (1), i.e. fatty-chain high molecular weight alkoxylates,
10 without however degrading or otherwise chemically reacting with said alkoxylates of formula
(1).
[0027] Treatment with an acid of pKa of less than or equal to 3.5 has proven to be
particularly effective on the impurities generated during the preparation of compounds of
formula (1), in particular ethoxylated or else ethoxylated and propoxylated compounds of
15 formula (1).
[0028] Acids of pKa of less than or equal to 3.5 which may be used in step b) of the process
of the present invention may be of any type known per se, organic or mineral acids,
Brønsted acids or Lewis acids. However, preference is given to using Brønsted acids,
proton-donating acids, having a pKa of less than or equal to 3.5, preferably of less than or
20 equal to 3, more preferably of less than or equal to 2.5, more preferably of less than or equal
to 2, i.e. strong proton-donating acids, also referred to as acids with labile hydrogen.
[0029] Among the acids very particularly suitable for the process of the present invention,
mention may be made, in a nonlimiting manner, of hydrochloric, sulfuric, nitric, and
phosphoric acids, but also sulfamic acid, para-toluenesulfonic acid, alkanesulfonic acids,
25 and also mixtures of two or more thereof in any proportions.
[0030] It has been observed that acids having a pKa of greater than 3.5 do not enable a
satisfactory chemical conversion of the impurities of unsaturated ether type generated
during the preparation of the high molecular weight fatty-chain alkoxylates, in particular
products of the ethoxylation or ethoxylation/propoxylation of high molecular weight fatty30 chain compounds. Within the meaning of the present invention, "high molecular weight" is
understood to mean a molecular weight, as measured by gel permeation chromatography
(GPC) generally of between 500 g/mol-1 and 20 000 g/mol-1
, preferably between 750 g/mol1 and 15 000 g/mol-1
, better still between 1000 g/mol-1 and 15 000 g/mol-1
, more particularly
between 1000 g/mol-1 and 10 000 g/mol-1
.
— 7 —
[0031] It should be understood that, when the alkoxylation reaction is carried out under
basic catalysis, it is possible to use the acid of pKa of less than or equal to 3.5 both as acid
making it possible to neutralize the basic catalyst and as acid making it possible to convert
the undesirable impurities into compounds that are more easily removable from the reaction
5 medium. It may, however, be advantageous for reasons of costs and convenience of the
industrial process to proceed with a first acidification, under conventional conditions known
to those skilled in the art, in order to neutralize the reaction medium and any basic catalyst
residue, and then a second acidification with an acid of pKa of less than or equal to 3.5, in
order to chemically convert the undesired impurities, as indicated above.
10 [0032] Thus, when it is desirable to neutralize the basic alkoxylation catalyst, the process
of the present invention also comprises a step a2) between step a) and step b), said step
a2) comprising the addition of an acid to the crude reaction medium obtained from step a).
The acid used for step a2) may be any type of acid well known to those skilled in the art,
whether strong or weak, organic or mineral, or else the acid used in step b) as will be
15 explained below.
[0033] For the needs of step b) of treating the optionally neutralized reaction medium of
the process according to the present invention, preference is given to using acids of pKa of
less than or equal to 3.5 which are perfectly miscible in the reaction medium, that is to say
barely capable, or not capable, of forming a separate phase in the reaction medium. In
20 addition, the preferred acids of pKa of less than or equal to 3.5 are those having the smallest
possible environmental impact.
[0034] Thus, a family of acids that is a very particularly suitable for the process according
to the present invention consists of the alkanesulfonic acids. In the present invention, the
term "alkanesulfonic acid" is preferentially understood to mean the alkanesulfonic acids of
25 the formula Ra-SO3H, where Ra represents a saturated, linear or branched hydrocarbonbased chain comprising from 1 to 4 carbon atoms.
[0035] The preferred alkanesulfonic acids for use in the context of the present invention
are chosen from methanesulfonic acid, ethanesulfonic acid, n-propanesulfonic acid,
isopropanesulfonic acid, n-butanesulfonic acid, isobutanesulfonic acid, sec-butanesulfonic
30 acid, tert-butanesulfonic acid, and mixtures of two or more thereof in any proportions.
[0036] According to a preferred embodiment, the alkanesulfonic acid used in the context
of the present invention is methanesulfonic acid or ethanesulfonic acid; entirely preferably,
the acid used is methanesulfonic acid.
[0037] Thus, the process according to the present invention employs, in step b) of treating
35 the reaction medium, at least one alkanesulfonic acid chosen from alkanesulfonic acids
— 8 —
comprising a linear or branched chain comprising from 1 to 4 carbon atoms, and preferably
at least methanesulfonic acid (more commonly denoted by its acronym MSA).
[0038] Said at least one alkanesulfonic acid that may be used in the process of the present
invention may be used as it is, or in combination with one or more other components, that
5 is to say in a formulation. Any type of formulation comprising at least one alkanesulfonic
acid may be suitable. As a general rule, the formulation comprises from 0.01% to 100% by
weight of alkanesulfonic acid, more generally from 0.05% to 90% by weight, in particular
from 0.5% to 75% by weight, limits included, of alkanesulfonic acid(s), relative to the total
weight of said formulation. It is for example possible to use formulations comprising from
10 0.01% to 40% by weight of alkanesulfonic acid, better still from 0.05% to 30% by weight,
more specifically from 0.5% to 20% by weight, limits included, of alkanesulfonic acid(s),
relative to the total weight of said formulation.
[0039] The formulation is for example an aqueous, organic or else aqueous-organic
formulation. The formulation may be prepared in the form of a concentrated mixture, said
15 concentrated mixture possibly being diluted by the final user. As a variant, the formulation
may also be a ready-to-use formulation, that is to say that it does not need to be diluted.
Finally, within the meaning of the present invention, the formulation may be a pure
alkanesulfonic acid, or else a mixture of pure alkanesulfonic acids, that is to say that the
formulation may contain only one or more sulfonic acids, without other formulation additive
20 or other solvent or diluent.
[0040] The concentration of alkanesulfonic acid(s) in the formulation may vary within wide
proportions. Those skilled in the art will know how to adjust the appropriate concentration
of acid in the formulation without undue burden.
[0041] It is for example possible to use concentrated solutions, for example from 60% to
25 100%, preferably approximately 70% to 100%, by weight of alkanesulfonic acid(s), relative
to the total weight of said formulation, or else less concentrated solutions of from 0.01% to
60%, preferably from 0.05% to 45%, advantageously from 0.1% to 40%, by weight of
alkanesulfonic acid(s), relative to the total weight of said formulation.
[0042] According to a very particularly preferred aspect of the present invention, the acid
30 of pKa of less than or equal to 3.5 used is methanesulfonic acid (pKa of -1.9). The
methanesulfonic acid may advantageously be that sold in aqueous solution by Arkema
under the name Scaleva®
, or else under the name Lutropur® sold by BASF, ready to use or
diluted in water in the proportions indicated above.
[0043] According to another aspect, the present invention relates to the use of an acid of
35 pKa of less than or equal to 3.5, preferably of an alkanesulfonic acid, and more preferably
— 9 —
of methanesulfonic acid, for the treatment of a reaction medium of the alkoxylation of a fattychain compound of the formula R-OH, where R is as defined above, and more particularly
for the treatment of an alkoxylation reaction medium for the preparation of a compound of
formula (1) as defined above.
5 [0044] Step b) of treatment with an acid of pKa of less than or equal to 3.5 may be carried
out at various temperatures and pressures. For obvious reasons of convenience of the
industrial process, preference is given to operation at atmospheric pressure. Likewise, the
treatment temperature is advantageously between ambient temperature and 130°C, and
more generally the treatment temperature is between 30°C and 120°C, for example
10 between 40°C and 100°C.
[0045] The duration of treatment with the acid of pKa of less than or equal to 3.5 may also
vary within wide proportions. The duration of contact with said acid is generally brief and is
generally between a few minutes and a few hours, preferably between 5 minutes and 1
hour, for example approximately 30 minutes.
15 [0046] The amount of acid required may vary within wide proportions, but is generally
between 4×10-3 and 0.1 mol per kg of reaction medium, preferably between 5×10-3 and
9×10-2 mol per kg of reaction medium, better still between 6×10-3 and 8×10-2 mol per kg of
reaction medium.
[0047] As indicated above, the acid of pKa of less than or equal to 3.5 is a proton-donating
20 acid and consequently requires the presence of a small amount of water which, if it is not
present in the reaction medium or provided by the acid formulation, may advantageously
be added to the reaction medium, for example during the acid treatment. This amount of
water, already present or provided during the process of the invention, may vary within wide
proportions and is generally between a few ppm by weight and a few % by weight, relative
25 to the total weight of the reaction medium treated with the acid of pKa of less than 3.5.
[0048] Step c) of recovering the alkoxylation product consists in treating the neutralized
reaction medium as has just been defined above, that is to say the reaction medium
obtained from step b) treated with an acid having a pKa of less than or equal to 3.5. The
treatment of step c) corresponds to the removal in full or at least to a very great extent,
30 according to the conventional techniques well known to those skilled in the art, of the
impurities chemically converted in step b) of the process of the invention.

CLAIMS
1. A process for preparing compounds of formula (1):
R-(Ak-O-)nH (1),
in which:
- R represents a linear or branched hydrocarbon-based fatty chain comprising from 8 to 60
carbon atoms, optionally comprising one or more saturated or unsaturated rings, and
possibly comprising one or more oxygen atoms,
- Ak represents an alkylene unit with 2, 3 or 4 carbon atoms, preferably with 2 or 3 carbon
atoms, and
- n is an integer between 10 and 250, preferably between 15 and 200, more preferably
between 18 and 160, limits included,
said process comprising at least the following steps:
a) reacting a compound of the formula R-OH with at least one alkylene oxide, in the
presence of a catalyst,
b) treating the reaction medium with an acid having a pKa of less than or equal to 3.5, and
c) recovering the compound of the formula R-(Ak-O-)nH by treatment of the thus-neutralized
reaction medium.
2. The process as claimed in claim 1, wherein the fatty chain R present in the
compound of formula (1) and the compound of the formula R-OH is a hydrocarbon-based
chain comprising from 8 to 60 carbon atoms, preferably from 8 to 40 carbon atoms, more
preferably from 10 to 30 carbon atoms, limits included, and may comprise one or more
saturated or partially or completely unsaturated rings, said fatty chain R also possibly being
saturated or comprising one or more unsaturations, most often in the form of double bonds,
triple bonds, or combinations of these unsaturations, and likewise possibly comprising one
or more oxygen atoms, for example in the form of ether, alcohol, acid or ester functions,
and also combinations of two or more of these oxygen-bearing functions.
3. The process as claimed in either of claims 1 and 2, wherein the compound of the
formula R-OH is chosen from fatty alcohols, fatty acids, fatty polyacids, alcohol esters, sugar
esters, glycerides, fatty-chain phenol derivatives, but also polyols, such as sugars, alkyl
polyglycosides, polyphenols, and also mixtures of two or more thereof, in any proportions.
— 15 —
4. The process as claimed in any one of the preceding claims, wherein the compound
of the formula R-OH is chosen from octanoic acid, nonanoic acid, decanoic acid,
undecanoic acid, undecylenic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic
acid, octadecanoic acid, 9-octadecenoic acid, 9,12-octadecadienoic acid, 9,12,15-
octadecatrienoic acid, arachidic acid, arachidonic acid, behenic acid, erucic acid, octanols,
nonanols, decanols, undecanols, undecenols, dodecanols, tetradecanols, hexadecanols,
octadecanols, oleyl alcohol, sorbitol esters, sorbitan esters, sorbitol ethers, sorbitan ethers,
isosorbide monoesters, isomannide monoesters, isoidide monoesters, isosorbide
monoethers, isomannide monoethers, isoidide monoethers, hydroxyethyl oleate, cardanol,
polyacids, tannins, lignans, lignins and other natural polyols or polyols derived from natural
products, and also mixtures of two or more thereof in any proportions.
5. The process as claimed in any one of the preceding claims, wherein the alkylene
oxide is chosen from ethylene oxide, propylene oxide and butylene oxide, and also mixtures
thereof in any proportions, preferably from ethylene oxide and propylene oxide, and also
mixtures thereof in any proportions, more preferably the alkylene oxide is ethylene oxide or
propylene oxide, and advantageously the alkylene oxide is ethylene oxide.
6. The process as claimed in any one of the preceding claims, wherein the
alkoxylation catalyst is a basic or alkaline catalyst chosen from sodium hydroxide or
potassium hydroxide, sodium alkoxides and potassium alkoxides, advantageously sodium
hydroxide or potassium hydroxide, more advantageously potassium hydroxide.
7. The process as claimed in any one of the preceding claims, wherein the acid of
pKa of less than or equal to 3.5 is a mineral or organic Brønsted acid or Lewis acids,
preferably a Brønsted acid.
8. The process as claimed in any one of the preceding claims, wherein the acid of
pKa of less than or equal to 3.5, is chosen from hydrochloric, sulfuric, nitric, and phosphoric
acids, but also sulfamic acid, para-toluenesulfonic acid, alkanesulfonic acids, and also
mixtures of two or more thereof in any proportions.
9. The process as claimed in any one of the preceding claims, wherein the acid of
pKa of less than or equal to 3.5 is chosen from methanesulfonic acid, ethanesulfonic acid,
n-propanesulfonic acid, isopropanesulfonic acid, n-butanesulfonic acid, isobutanesulfonic
— 16 —
acid, sec-butanesulfonic acid, tert-butanesulfonic acid, and mixtures of two or more thereof
in any proportions, and preferably the acid of pKa of less than or equal to 3.5 is
methanesulfonic acid or ethanesulfonic acid, and entirely preferably methanesulfonic acid.
10. The process as claimed in any one of the preceding claims, wherein the compound
of formula (1) is one of the alkoxylates from the following list:
● C16-C18 alcohol with 33 OE,
● C10 oxo alcohol with 20 OE,
● C16-C18 alcohol with 18 OE,
● (C18) oleyl alcohol with 20 OE,
● stearic acid ethoxylated with 120 OE,
● rapeseed oil with 20 OE,
● rapeseed oil with 30 OE,
● hydrogenated castor oil with 25 OE,
● hydrogenated castor oil with 20 OE,
● ester of sorbitan monolaurate with 20 OE,
● ester of sorbitan monostearate with 20 OE,
● ester of sorbitan monooleate with 20 OE,
● coconut fatty acid with 150 OE.
11. The use of an acid of pKa of less than or equal to 3.5, preferably of an
alkanesulfonic acid, and more preferably of methanesulfonic acid, for the treatment of a
reaction medium of the alkoxylation of a fatty-chain compound of the formula R-OH, where
R is as defined in claim 1, and more particularly for the treatment of an alkoxylation reaction
medium for the preparation of a compound of formula (1) as defined in claim 1.