CA2107684A1

CA2107684A1 - A process for the production of fatty alcohol polyalkylene glycol ethers

Info

Publication number: CA2107684A1
Application number: CA 2107684
Authority: CA
Inventors: Hans-Christian Raths; Wolfgang Breuer; Ansgar Behler; Elvira Scholz
Original assignee: Individual
Current assignee: Henkel AG and Co KGaA
Priority date: 1991-04-04
Filing date: 1992-03-26
Publication date: 1992-10-05
Also published as: AU1433992A; EP0579636A1; TR25779A; WO1992017431A1; MX9201550A; DE4110834A1; JPH06505986A

Abstract

Fatty alcohol polyalkylene glycol ethers with improved filtrability are obtained if fatty alcohols of formula R1-OH, in which R1 is an aliphatic hydrocarbon radical with 6 to 24 carbon atoms and 0, 1, 2 or 3 double bonds, are caused to react in the presence of layer compounds with an average of 1 to 20 mol ethylene and/or propylene oxide per mol fatty alcohol, the reaction product is mixed with water and a filter auxiliary and the catalyst and the polyglycol ethers formed are separated out, possibly at high temperatures and/or pressures.

Description

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~ Wo 92/17431 21 0 7 6 3 ~ PCT/EPg2~00677 A proces for the production of fatty alcohol polyalkylene glycol ethers This invention relates to a process for the ,~ production of fatty alcohol polyalkylene glycol ethers having improved filterability by alkoxylation of fatty - alcohols in the presence of layer compounds and subse-quent working up.
8y virtue of their excellent detergent properties . and their high solubility in cold water, adducts of ethylene and/or propylene oxide with primary alcohols, so-called fatty alcohol polyalkylene glycol ethers, are acquiring increasing significance as nonionic surfac-3~ tants for the production of laundry detergents, dish-~i`$3 washing detergents and cleaning products. However, in the alkoxylation reaction, which is generally carried ~ out in the presence of readily soluble alkali metal ^'s 15 hydroxides or alcoholates, is not accompanied by the !~ selective addition of a discrete number of ethylene : and/or propylene oxide units onto one molecule of the , alcohol, instead the reaction follows statistical laws i~ and leads to a mixture of homologous addition products of which the degrees of alkoxylation cover a broad spec-trum.
i It is known from J. ~m. Oil. Chem. Soc. 63, 691 ~1986) and HAPPI 52 (19~6) that the distribution of the degrees of alkoxylation in the mixture of the alcohol ~j 25 alkoxylates, the so-called "homolog distribution", . ., 1 critically influences the properties of the addition products obtained. It has been found in this regard ;
;i~ that products with a "narrow" homolog distribution, which are known as narrow-range alkoxylates, have advantages over comparable products with a "broad"
homolog distribution, including for example:

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~ 92/17431 2 PCT/EP92~00677 - lower pour points, - higher smoke points, - a smaller number of mols of alkylene oxide to achieve solubility in water, - smaller contents of unreacted alcohol and hence reduced odor emission and - reduction of pluming during the spray drying of : detergent slurries containing polyglycol ethers.
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Suitable processes for the production of narrow-, range fatty alcohol polyalkylene glycol ethers are ~ known, for example, from DE-A1-38 43 713 and from US
!.'~ 4,962,237. In both processes, the alkoxylation of fatty alcohols is carried out in the presence of inorganlc 15 layer compounds, for example calcined hydrotalcite.
Ai During the reaction, the layer compounds insoluble in the reaction mixture are colloidally dispersed. The effect of this is that the necessary removal of the ~ catalyst after the alkoxylation reaction involves ;~ 20 considerable difficulties, for example blockage of the filter pores, frequent filter changés, etc.
Another problem in the production of fatty alcohol polyglycol ethers by the processes mentioned ' above is the formation of polyalkylene glycol ethers 25 (PAG) having molecular weights of about 400 to 2500 ~A which, due to traces of water, are inevitably formed as $ secondary products and represent self-polymerization products of the alkylene oxide used. Even small quanti-ties of PAG can cause the alkoxylation product to assume a gel structure which additionally impedes filtration and occasionally brings it to a complete standstill ~' through the formation of wax-like coatings on the `~ filter.
Although the use of conventional filter aids, for example cellulose acetate or kieselguhr, results in .. ; :

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., , , r ~r- 2 1 0 7 6 8 4 ` WO 92/17431 3 PC~/EP92/00677 shortening of the filtration times in these cases, ; considerable quantities of the required alkoxylation ~ product are also bound besides the PAG because adsorp-tion is not selective. This is of course undesirable and adversely affects the economy of the process. In ' addition, the filtrates obtained are generally cloudy -~ immediately after filtration or gradually become cloudy.
; Accordingly, the problem addressed by the present invention was to provide a process for the production of - 10 fatty alcohol polyalkylene glycol ethers which would not have any of the disadvantages described above.
he present invention relates to a process for ~ the production of ratty alcohol polyalkylene glycol i ethers having improved filterability by alkoxylation of . 15 fatty alcohols in the presence of catalysts insolubie in the reaction mixture, characterized in that - fatty alcohols corresponding to formula (I):

Rl-OH (I) in which R1 is an aliphatic hydrocarbon radical contain-ing 6 to 24 carbon atoms and 0, 1, 2 or 3 double bonds, are reacted with on average 1 to 20 mol ethylene and/or propylene oxide per mol fatty alcohol in the presence of ,J 25 layer compounds, the reaction product is treated with water and a filter aid and the catalyst and the polygly-col ethers formed are removed, optionally at elevated , temperature and/or elevated pressure.
`~ It has surprisingly been found that both the insoluble catalyst and most of the polyglycol ethers formed can be successfully separated if the alkoxylation products are treated together with a filter aid and water. It has proved to be of particular advantage in ~' this regard to carry out the separation at elevated temperature. In this way, it is possible to obtain .''.!
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clear, storable alkoxylation products in very short times with minimal product losses.
Suitable starting materials for the production of the fatty alcohol polyalkylene glycol ethers are fatty alcohols containing 6 to 24 carbon atoms and o, 1, 2 or 3 double bonds, of which typical examples are caproic alcohol, caprylic alcohol, capric alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, oleyl alcohol, elaidyl alco-hol, petroselinyl alcohol, gadoleyl alcohol, behenyl alcohol or erucyl alcohol. Saturated fatty alcohols ~, containing 8 to 18 car~on atoms, particularly lauryl alcohol, are preferably used.
As usual in oleochemistry, the alcohols may also be used in the form of the technical mixtures obtain-! able, for example, by high-pressure hydrogenation of fatty acid methyl ester cuts of vegetable or animal origin or by hydrogenation of technical aldehyde frac-tions from Roelen's oxo synthesis. Technical coconut ' 20 oil alcohol, a mixture of C121a fatty alcohols, is ~ preferably used.
J, In the context of the process according to the i invention, layer compounds are understood to be natural or synthetic, optionally chemically modified hydrotal-3 25 cites. Hydrotalcites are known chemical compounds and may be obtained, for example, by reaction of aqueous suspensions of aluminium hydroxide gel, basic magnesium carbonate and magnesium hydroxide or oxide at tempera-tures in the range from 70 to 85C ~DE-B1-33 06 822].
Catalysts suitable for use in the process accord-ing to the invention are, in particular, calcined hydro-! talcites which before calcination correspond to formula M(II)~ I)oH[) ( C03) z n H2O (II) :

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` -`` 210768 1 -` WO 92~17431 5 PCT/EP92/00677 ,:' ~ in which ',: M(II) is a divalent metal ion and ~ M(III) is a trivalent metal ion .~: 5 and for which the conditions 1 < x < 5, y > z, (y + 2z) :: = (2x + 3) and 0 < n < 10 are fulfilled.
i-~ Suitable divalent metal ions are Ca2', Sr2t, Ba2+.
Mn2~ Fe2+ Co2t Ni2t, Zn2t, Cu2~ and, in particular, Mg -Suitable trivalent metal ions are Ga3+, Fe3+, La3+, Cr3+, Mo3+ and, in particular, Al3.
: Calcined hydrotalcites can be obtained by heating . , . natural or synthetic hydrotalcites at temperatures above , 450C [DE-Al-38 43 713].
In another embodiment of the process according to .~ the invention, the catalysts used may also be hydropho-- bicized hydrotalcites corresponding to formula ~III):
~ .-~ M(II)~'III)oH)b~co3)c~A)d m 2 ~III) ., 20 . in which . tI is a divalent metal ion, M(III) is a trivalent metal ion and A is the dianion of an aliphatic dicarboxylic acid . ~, .
.~ 25 containing 4 to 44 carbon atoms or two anions of 3 aliphatic monocarboxylic acids containing 2 to 34 carbon atoms .~ and the conditions 1 < a < 5, b > (2a + 2~, [b + 2(c +
.~. d)] = (2a + 3), (c + d) < 0.5, c > 0, d > 0 and 0 < m <
. 30 10 are fulfilled.
.~ Suitable divalent and trivalent metal ions are, ' again, the ions already mentioned. Typical examples of the nature of the ionic group A are the dianions of . ~
. malonic acid, maleic acid, succinic acid or adipic acid .3 35 and the anions of lauric acid, stearic acid or oleic ,: .
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~ydrophobicized hydrotalcites can be obtained, for example, by stirring hydrotalcite into isopropyl alcohol and adding a fatty acid to and then filtering the suspension. Before they are used, the hydrophobi-cized hydrotalcites are merely dried and not calcined.
Alkoxylation is an lndustrial process known per , se. To produce the fatty alcohol polyalkylene glycol ethers, the fatty alcohols are reacted with 1 to 20 mol ;' 10 and preferably with 2 to 10 mol ethylene and/or propy-lene oxide in the presence of 0.1 to 5% by weight and ' !
~ preferably in the presence of 0.5 to 1% by weight, based ~ on the expected aIkoxylation product, of the layer ; compound. In a preferred embodiment, 1 to 10 mol ` 15 ethylene and/or propylene oxide are added onto saturated alcohols containing 8 to 1~ carbon atoms.
The alkoxylation may be carried out in a pressure vessel, for example in an autoclave, in known manner at temperatures of 120 to 220C and preferably at tempera-~ 20 tures of 160 to 200C under pressures of 1 to 5 bar and iv, preferably under pressures of 2 to 4 bar.
i~ After the alkoxylation reaction, water and a filter aid are added to the crude alkoxylation product which contains the layer compound used as catalyst and ~' 25 also the polyglycol ethers formed in the form of a colloidal dispersion.
Suitable filter aids are, for example, kieselguhr (Celite~), wood meal (Arbocel~), fine-particle cellulose (Lignocell~) or cellulose acetate (Primisil~). The filter aids may be used in concentrations of 0.1 to 10%
by weight and preferably in concentrations of 0.5 to 5%
by weight, based on the alkoxylation product. The quantity of water to be used together with the filter aid may be between 0.1 and 15% by weight and is prefer-, ~ 35 ably between 5 and 10% by weight, based on the alkoxyla-,~
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- tion product. The ratio by weight of water to filter aid is not critical and may be, for example, from 1:5 to 5:1.
The insoluble catalyst and the polyglycol ethers formed may be separated, for example, by centrifugation, but especially by filtration, for example using through- -flow filters (filter candles, Seitz filters, etc.), - filter presses or rotary filters.
The filtration rate ls influenced to a large ` 10extent by the quality of the filter cake. The filter cakes formed in the process according to the invention , : have a loose to almost crystalline structure and may readily be separated from the filter.
The filtration conditions are limited by the i 15solidification points of the products. In principle, filtration may be carried out at temperatures of 0 to 100C and preferably at temperatures of 25 to 70C under pressures of 1 to 10 bar. To ensure a short filtration time, minimal product losses and high stability in storage, it has proved to be optimal to carry out filtration at temperatures in the range from 50 to 70C
,and under pressures of 1 to 5 bar.
sIn one preferred embodiment of the process, the ~alkoxylation product is cooled to 70 to 90C immediately .. ~! 25 after leaving the pressure vessel and, after the addi-;~tion of 7 to 10% by weight water and 1 to 3~ by weight filter aid (based in each case on the alkoxylation product), is subjected to hot filtration.
~`The fatty alcohol polyalkylene glycol ethers obtainable by the process according to the invention are ~,easy to filter, are clear and are suitable for the r~production of, for example, detergents and cleaning products and hair-care and personal hygiene products in which they may be present in quantities of 0.1 to 25% by weight, based on the solids content of the particular :,!

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The following Examples are intended to illustrate `~ the invention without limiting it in any way.
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;;- I. Production of the starting materials Calcined hydrotalcite. A commercial synthetic hydrotal-cite was calcined for 8 h at 500C.

C~,~ coconut oil fatty alcohol + 2.S mol EO ~). 250 g (1.3 mol) cl2~l4 coconut oil fatty alcohol (Lorol~ S, .;,~ hydroxyl value 290, a product of E~enkel KGaA) were introduced into a pressure reactor and 3 g, correspond-ing to 0.5~ by weight (based on the expected alkoxyla-tion product), of the calcined hydrotalcite produced beforehand were subsequently added. The-reactor was purged with nitrogen and evacuated for 30 minutes at a temperature of 100C. The temperature was then in-j creased to 180C and 143 g (3.25 mol) ethylene oxide were introduced in portions under a pressure of 4 bar over a period of 90 minutes. After the ethylene oxide had been added, the mixture was left to react for 30 minutes. After venting of the autoclave, approx. 390 g of an adduct of, on average, 2.5 mol ethylene oxide with coconut oil fatty alcohol were obtained.

~ II. Filtration tests ,~ 30 Into 500 g of an adduct of on average 2.5 mol ethylene oxide with a coconut oil fatty alcohol (A) were stirred the corresponding quantities of filter aid and water at a temperature of 25 to 90~C. The alkoxylation , 35 catalyst and most of the PAG formed were then filtered ..~

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WO 92/17431 9 PCT/EP92~00677 ; off under pressure.
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Filter : 2 . 2 1 SEITZ pressure filter, type EF 14/2, with an outer jacket temperature-controlled by a HAAKE
F3 thermostat Pressure : 2.5 bar Filter layer : BEGEROW E~D 7 filter layer (diame-: ter: 12 cm) ,. 10 The results are set out in Table 1.

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, Table 1:
, Filtration of coconut oil fatty alcohol 2.5 EO
- Percentages as % by weight, based on (A) -~ Ex. FA cFA cH2O T CH CW PL CV Ft ' % % ~C mm g % ml/g mins.
1 Primisil 2.0 7.0 70 1.5 21.5 1.8 3.2 0.9 - 2 Primisil 2.0 5.0 70 2.0 23.5 2.2 3.8 1.4 3 Primisil 2.0 7.0 25 2.5 24.0 2.3 4.7 3.2 4 Primisil 2.0 5.0 25 3.0 26.0 2.7 5.2 3.4 ~ 5 Primisil 2.0 10.0 25 2.0 20.0 1.5 4.5 2.8 .~ . .
s Cl None - - 25 1.0 32.5 6.0 1.3 85.0 ;~ C2 Primisil 2.0 - 25 4.0 37.8 5.1 4.8 4.1 '' C3 Primisil 2.0 - 70 3.0 29.0 3.3 6.2 1.9 ~' .
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FA : Filter aid !l cFA : Concentration of filter aid l cH2O: Concentration of water ~, T : Filtration temperature S:H : Height of filter cake . . .

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:~ CW : Weight of filter cake .. PL : Product loss CV : Specific volume of the filter cake ,- Ft : Filtration time The filtrates of Examples 1 to 5 were clear both at elevated temperature and at room temperature.

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Claims

1. A process for the production of fatty alcohol polyalkylene glycol ethers having improved filterability by alkoxylation of fatty alcohols in the presence of catalysts insoluble in the reaction mixture, charac-terized in that fatty alcohols corresponding to formula (I):

R1-OH (I) in which R1 is an aliphatic hydrocarbon radical contain-ing 6 to 24 carbon atoms and 0, 1, 2 or 3 double bonds, are reacted with on average 1 to 20 mol ethylene and/or propylene oxide per mol fatty alcohol in the presence of layer compounds, water and a filter aid are added to the reaction product and the catalyst and the polyglycol ethers formed are removed, optionally at elevated temperature and/or elevated pressure.

2. A process as claimed in claim 1, characterized in that saturated fatty alcohols containing 8 to 18 carbon atoms are used.

3. A process as claimed in claims 1 and 2, charac-terized in that the layer compounds used are calcined hydrotalcites which before calcination correspond to formula (II):

M(II)xM(III)OH)y(CO3)z ? n H2O (II) in which M(II) is a divalent metal ion and M(III) is a trivalent metal ion and for which the conditions 1 < x < 5, y > z, (y + 2z) = (2x + 3) and 0 < n < 10 are fulfilled.

4. A process as claimed in claims 1 and 2, charac-terized in that the layer compounds used are hydrophobi-cized hydrotalcites corresponding to formula (III):

M(II)aM(III)OH)b(CO3)c(A)d ? m H2O (III) in which M(II) is a divalent metal ion, M(III) is a trivalent metal ion and is the dianion of an aliphatic dicarboxylic acid containing 4 to 44 carbon atoms or two anions of aliphatic monocarboxylic acids containing 2 to 34 carbon atoms and the conditions 1 < a < 5, b > (2a + 2), [b + 2(c +
d)] = (2a + 3), (c + d) < 0.5, c > 0, d > 0 and 0 < m <
10 are fulfilled.

5. A process as claimed in at least one claims 1 to 4, characterized in that the layer compounds are used in concentrations of 0.1 to 5% by weight, based on the expected alkoxylation product.

6. A process as claimed in at least one of claims 1 to 5, characterized in that the alkoxylation is carried out with 1 to 10 mol ethylene and/or propylene oxide per mol fatty alcohol.

7. A process as claimed in at least one of claims 1 to 6, characterized in that the alkoxylation is carried out at temperatures of 120 to 220°C under pressures of 1 to 5 bar.

8. A process as claimed in at least one of claims 1 to 7, characterized in that substances selected from the group consisting of kieselguhr, wood meal, cellulose or cellulose acetate are used as the filter aid.

9. A process as claimed in at least one of claims 1 to 8, characterized in that the filter aids are used in quantities of 0.1 to 10% by weight, based on the alkoxy-lation product.

10. A process as claimed in at least one of claims 1 to 9, characterized in that water is used in quantities of 0.1 to 15% by weight, based on the alkoxylation product.

11. A process as claimed in at least one of claims 1 to 10, characterized in that the separation step is carried out at temperatures of 0 to 100°C.

12. A process as claimed in at least one of claims 1 to 11, characterized in that the separation step is carried out under pressures of 1 to 10 bar.

13. A process as claimed in at least one of claims 1 to 12, characterized in that the catalyst and the polyglycol ethers formed are separated by filtration.