EP0573448A1

EP0573448A1 - Process for producing alkyl- and/or alkenylsulfate pastes with improved flowability.

Info

Publication number: EP0573448A1
Application number: EP92903962A
Authority: EP
Inventors: Andreas Syldath; Karl Schmid; Ditmar Kischkel
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1991-02-25
Filing date: 1992-02-17
Publication date: 1993-12-15
Anticipated expiration: 2012-02-17
Also published as: ATE123801T1; DE59202552D1; ES2073288T3; JPH06505042A; DK0573448T3; DE4105851A1; EP0573448B1; WO1992014809A1

Abstract

Alkyl- and/or alkenylsulfate pastes with improved flowability may be produced by admixture of at least one nonionic tenside selected from the group composed of: (a) alkyl- and/or alkenylpolyethyl glycolether, (b) alkyl- and/or alkenylpolypropylene glycolether; (c) alkyl- and/or alkenylpolypropyleneglycol-ethylene glycolether; (d) alkyl- and/or alkenyl glycosides; (e) mixed ethers and/or (f) hydroxyl mixed ethers. The viscosity of the alkyl- and/or alkenylsulfate pastes is set at 15.000 mPa.s maximum at 55 C.

Description

Process for the preparation of alkyl and / or alkenyl sulfate pastes with improved flowability

The invention relates to a process for the preparation of alkyl and / or alkenyl sulfate pastes with improved flowability by adding nonionic surfactants as viscosity reducers.

Anionic surfactants of the alkyl and alkenyl sulfate type, especially those containing alkyl or alkenyl radicals with 16 to 18 carbon atoms, show excellent detergent properties and are suitable for the production of detergents, dishwashing detergents and cleaning agents.

The technical use of alkyl and / or alkenyl sulfates, in particular for the production of powder detergents, has hitherto been limited since the storage and transport of aqueous alkyl and / or alkenyl sulfate pastes is associated with serious problems. For example, alkyl and / or alkenyl sulfate pastes with solids contents of 30 to 70% by weight at ambient temperature have such a high viscosity and such a strong flow anomaly (rheopexy) that transferring or pumping around is practically impossible. Mixing the pastes with other detergent ingredients also leads to largely inhomogeneous slurries that cannot be processed without problems. One way out could be to heat the pastes to a sufficiently high temperature and thus make them flowable. However, since alkyl and / or alkenyl sulfates begin to decompose at temperatures around 80 ° C, storage under these conditions is only possible with the most careful pH control and, if necessary, the addition of alkali.

The alternative of lowering the viscosity of alkyl and / or alkenyl sulfate pastes by diluting them with water to such an extent that pumping around is also disadvantageous, since an unnecessary mass transport during the spray drying of the pastes for the production of powdery products with an excessive expenditure of energy would be connected.

In the past, the problem of high viscosity aqueous anionic surfactant pastes has been the subject of a variety of studies. As a representative, reference should be made to the German patent application DE 3718896 AI, in which the use of alkoxylated alcohols as viscosity reducers for alkylbenzenesulfonate pastes is proposed.

According to the teaching of European patent EP 0 116 905 B1, the viscosity of alkyl aryl sulfate, alpha sulfofatty acid ester and alkyl sulfate pastes can be increased by adding 1 to 15% by weight, based on the surfactant content, of an adduct of 1 to 15 mol of ethylene - And / or propylene oxide on alcohols with 8 to 40 carbon atoms can be reduced to values below 10,000 mPa.s at 70 ° C. This publication is primarily concerned with the viscosity control of alpha-sulfofatty acid ester salt pastes. However, studies have shown that the addition of the alkylene oxide adducts mentioned to alkyl and / or alkenyl sulfate Although pastes lead to a sufficient reduction in viscosity at high temperatures, at the same time the detergent properties, in particular the washing power, can deteriorate. In addition, the use of the alkylene oxide adducts in the spray drying of the alkyl and / or alkenyl sulfate pastes can lead to an increased product discharge and an undesirable pollution of the exhaust air with organic cargo ("pluming").

The object of the invention was therefore to provide a process for the preparation of alkyl and / or alkenyl sulfate pastes with improved flow properties which is free from the disadvantages described.

The invention relates to a process for the preparation of alkyl and / or alkenyl sulfate pastes with improved flow properties, which is characterized in that aqueous pastes of alkyl and / or alkenyl sulfates of the formula (I),

RI-O-SO3X (I) in which R ^{1 is} an alkyl and / or alkenyl radical having 10 to 22 carbon atoms and X is an alkali or alkaline earth metal which has a solids content of 30 to 70% by weight, at least one nonionic surfactant selected from the group formed by a) alkyl and / or alkenyl polyethylene glycol ether,

b) alkyl and / or alkenyl polypropylene glycol ether,

c) alkyl and / or alkenyl polypropylene glycol ethylene glycol ether, d) alkyl and / or alkenyl glycosides,

e) mixed ethers and / or f) Hydroxy mixed ether is added, the viscosity of the alkyl and / or alkenyl sulfate pastes being at most 15,000 mPa.s at 55 ° C.

Surprisingly, it was found that the selected nonionic surfactants to be used by the process according to the invention not only reduce the viscosity of alkyl and / or alkenyl sulfate pastes so much even at low temperatures that pumping around is possible without the risk of chemical decomposition, but also that Eliminate flow anomaly, which is a significant relief for the design of delivery pumps and delivery routes for the alkyl and / or alkenyl sulfate pastes. The invention includes the knowledge that the addition of the nonionic surfactants makes it possible to produce homogeneous detergent slurries. The washing, rinsing and cleaning ability of the alkyl and / or alkenyl sulfate pastes is not negatively influenced in the sense of the process according to the invention by the addition of the nonionic surfactants. Finally, the pastes can be sprayed without pluming problems. For this purpose, polyethylene glycol ethers with a narrow homolog distribution have proven to be particularly advantageous.

Alkyl and alkenyl sulfates are known anionic surfactants which can be obtained by the usual methods of preparative organic chemistry. As a rule, they are produced by reacting saturated and / or unsaturated, aliphatic primary alcohols with sulfur trioxide. Alkyl and / or alkenyl sulfates to which the process according to the invention extends are derived from fatty alcohols having 10 to 22 carbon atoms. Typical examples are carpinal alcohol, Lauryl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol or erucyl alcohol. A particularly drastic reduction in the paste viscosity is observed with alkyl sulfates which are derived from saturated fatty alcohols having 12 to 18, in particular 16 to 18, carbon atoms.

The alkyl and / or alkenyl sulfates can also be derived from technical alcohol cuts, such as z. B. natural in the hydrogenation of technical fatty acid methyl esters

Origin or aldehydes from Roelen's oxosynthesis. Alkyl and / or alkenyl sulfates based on technical coconut or tallow alcohol cuts are preferred. These are primary fatty alcohols that have the following average C chain distribution:

Coconut alcohol tallow alcohol

C ₁₀ : 0-3% by weight

C ₁₂ : 48-58% by weight

C ₁₄ : 19-24% by weight 0-3% by weight

C ₁₆ : 9-12% by weight 45-55% by weight

C ₁₈ : 11-14% by weight 45-55% by weight

C ₂₀ : 0-3% by weight For the purposes of the invention, nonionic surfactants include a) alkyl and or alkenyl polyethylene glycol ethers,

b) alkyl and / or alkenyl polypropylene glycol ether,

e) mixed ethers and / or

f) to understand hydroxy mixed ethers. All of these surfactants are known compounds, the preparation of which - unless stated otherwise - is, for. B. J.Falbe, U. Hasserodt (ed.), "Catalysts, surfactants and mineral oil additives, Thiene Verlag, Stuttgart, 1978 or J.Falbe (ed.)" Surfactants in Consuner Products ", Springer Verlag, Berlin, 1986 is.

Non-ionic surfactants which correspond to the formula (II) can be used as alkyl and / or alkenyl polyethylene glycol ethers (component a) in the process according to the invention:

R ² -O- (CH ₂ -CH ₂ -O) _n H (II) follow, in which R ^{2 represents} a linear or branched alkyl or alkenyl radical having 6 to 22 carbon atoms and n represents numbers from 2 to 7. In view of a significant reduction in the viscosity of the alkyl and / or alkenyl sulfate pastes, good detergent properties and particularly low pollution of the exhaust air during spray drying, it has proven to be optimal to use alkyl polyethylene glycol ethers of the formula (II) in which R ^{2 is} a linear one or branched alkyl radical with 10 to 18 Carbon atoms and n represents numbers from 2 to 7, in particular 5 to 7.

In a further preferred embodiment of the invention, alkyl and / or alkenyl polyethylene glycol ethers of the formula (II) can be used, the residual alcohol content of which, for example by distillation, has been reduced to a content of less than 1% by weight, based on the nonionic surfactant.

Component b) includes alkyl and / or alkenyl polypropylene glycol ethers of the formula (III)

into consideration, in which R _{3 represents} a linear or branched alkyl or alkenyl radical having 6 to 22 carbon atoms and m represents numbers from 1 to 4. Preferred is the use of alkyl polypropylene glycol ether of the formula (II) in which R ^{3 represents} a linear alkyl radical having 10 to 18 carbon atoms and m represents numbers from 1 to 3.

As component c) come alkyl and / or alkenyl polypropylene glycol ethylene glycol ethers of the formula (IV)

into consideration, in which R ^{4 represents} a linear or branched alkyl or alkenyl radical having 6 to 22 carbon atoms, p stands for numbers from 1 to 4 and q stands for numbers from 1 to 10. Preferred is the use of alkyl polypropylene glycol ethylene glycol ether of the formula (IV) in which R ^{4 represents} a linear alkyl radical having 10 to 18 carbon atoms, p represents 1 or 2 and q represents numbers from 1 to 7.

The alkyl polyglycol ethers, which form components a), b) and c), are addition products of ethylene and / or propylene oxide onto native fatty alcohols or synthetic oxo alcohols. Since the alkoxylation is a statistical reaction, the technical alkyl polyglycol ethers can homologs of different degrees of alkoxylation and unreacted Contain fatty alcohol. In the sense of the process according to the invention, both homologue-pure alkyl polyglycol ethers and technical mixtures, both with broad and narrow homolog distribution, can be used.

Component d) includes alkyl and / or alkenyl glycosides of the formula (V)

R ⁵ -O- (G) _x (V) into consideration, in which R ^{5 represents} an alkyl or alkenyl radical having 6 to 22 carbon atoms, G represents a glycose unit derived from a sugar having 5 or 6 carbon atoms and x stands for a number between 1 and 10. The alkyl and / or alkenyl glycosides can moreover contain small amounts, depending on the production, but not more than 10% by weight, based on the alkyl and / or alkenyl glycoside, of alcohol. Preferred is the use of alkyl glycosides of the formula (V) in which R ^{5 is} is an alkyl radical having 10 to 18 carbon atoms, G is a glucose radical and x is a number from 1 to 3, in particular 1.1 to 1.6. For the preparation of the alkyl and / or alkenyl glycosides, reference is made to the German patent application DE 3723826 A1.

Mixed ethers of the formula (VI) are used as component e)

into consideration, in which R ^{6 represents} an alkyl or alkenyl radical having 6 to 22 carbon atoms, R ^{7 represents} an alkyl radical having 1 to 4 carbon atoms or a benzyl radical, R ^{8 represents} hydrogen or a methyl group and y represents numbers from 1 to 10. Preference is given to using mixed ethers of the formula (VI) in which R ^{6 is} an alkyl radical having 12 to 18 carbon atoms, R ^{7 is} a butyl or benzyl radical, R ^{8 is} hydrogen and y is a number from 4 to 10.

Hydroxy mixed ethers of the formula (VII) are used as component f)

into consideration, in which R ^{9 represents} an alkyl radical having 6 to 16 carbon atoms, R ^{10 represents} an alkyl radical having 1 to 4 carbon atoms or a benzyl radical, R ^{11 represents} hydrogen or a methyl group and z represents numbers from 1 to 10. Preference is given to using hydroxy mixed ethers of the formula (VII) in which R ^{9 is} an alkyl radical with 8 to 10 carbon atoms, R ^{10 represents} a butyl or benzyl radical, R ^{11 represents} hydrogen and z represents numbers from 4 to 10. For the preparation of the hydroxy mixed ethers, reference is made to the German patent application DE 3723323 A1.

The nonionic surfactants can be added to the alkyl and / or alkenyl sulfate pastes individually or in combinations, the mixing ratio being able to vary over a wide range. For example, the use of a mixture containing polyglycol ethers, in particular alkyl polyethylene glycol ether, and alkyl glucosides in a weight ratio of 10:90 to 90:10, whose free alcohol content is less than 1% by weight, based on the mixture, has proven particularly advantageous.

In order to lower the viscosity and the yield point of the alkyl and / or alkenyl sulfate pastes, the nonionic surfactants can the alkyl and / or alkenyl sulfates in amounts of 1 to 15, preferably 5 to 12 wt .-% - based on the solids content of the Pastes - either added during or after neutralization. With regard to the use of the alkyl and / or alkenyl polyethylene glycol ether (component a), it has proven to be particularly advantageous to use these nonionic surfactants in amounts of 5 to 12, in particular 7.5 to 10,% by weight, based on the solids content of the Pastes - to be used. The alkyl and / or alkenyl sulfates can be mixed with the nonionic surfactants by mechanical means, for example by stirring or pumping, if appropriate at temperatures from 55 to 70 ° C .; there is no chemical reaction between the components. The following examples are intended to explain the subject matter of the invention in more detail without restricting it.

Examples

I. Preparation of the alkyl sulfatoasts (A)

600 g (2.3 mol) of C _16/18 tallow alcohol (hydrenol ^(R) DD, hydroxyl number 215, from Henkel KGaA) were placed in a 1-1 sulphonation reactor with jacket cooling and gas inlet tube and at T - 80 ° C with 240 g (3 mol) of sulfur trioxide reacted. The sulfur trioxide was expelled from a corresponding amount of 65% by weight oleum by heating, diluted to a concentration of 5% by volume with nitrogen and introduced into the starting product within 60 minutes. The crude sulfation product was then neutralized with aqueous 25% by weight sodium hydroxide solution and buffered with 1% by weight, based on the solids content, citric acid.

Characteristics of the product:

Anionic surfactant content 49.8% by weight

Unsulfated components 4.0% by weight

Sodium sulfate 1.4% by weight

Water 44.8% by weight

The anionic surfactant content and the unsulfonated contents were determined according to the DGF standard methods, Stuttgart, 1950-1984, H-III-10 and G-II-6b. The sulfate content was calculated as sodium sulfate, the water content was determined according to the Fischer method. II. Viscosity of tallow alkyl sulfate / fatty alcohol polyethylene glycol ether mixture

The viscosities of the mixtures according to the invention (examples 1 to 3) and of the comparison mixtures (V1 to V4) were measured in a Brookfield viscometer type RVT (spindle no. 6, speed 20) at temperatures from 55 to 75 ° C. The results are summarized in Tab. 1.

Tab. 1: Viscosities (specified in mPa.s)

E.g. additive conc. Temperature (° C)

% By weight 75 70 65 60 55

LT5 5.0 3,500 3,500 4,500 7,500 14,500

7.5 2,750 3,000 3,500 5,500 12,000

10.0 2,250 2,250 3,250 3,500 5,250

LT7 5.0 3,500 3,500 4,500 7,500 14,500

7, 5 3,000 3,250 3,750 5,750 13,250

10.0 3,000 3,250 3,500 6,500 11,000

LS3 / LT5 5.0 3,250 3,500 4,250 6,000 12,500

(80:20) 7.5 3,000 3,250 4,000 4,250 8,000

10.0 5,550 6,000 6,000 4,750 6,250 Continuation of Tab. 1: Viscosities

E.g. additive conc. Temperature (° C)

% By weight 75 70 65 60 55

V1 TA5 5.0 2,750 3,000 3,500 5,000 19,250

V2 TA7 5.0 3,000 3,000 4,000 5,500 38,750

V3 TA14 5.0 3,000 3,000 4,000 6,000 41,000

V4 TA20 5.0 3,000 3,500 4,500 8,000 47,500

Legend: LT5 = adduct of 5 mol on average

Ethylene oxide with a C _{_12/18} fatty alcohol

LT7 = adduct of 7 mol on average

Ethylene oxide with a C _{_12/18} -Fefrtalkohol

LS3 / LT5 = mixture of an adduct of an average of 5 moles ethylene oxide with a C _{_12/14} - fatty alcohol un of an adduct of an average of 5 moles ethylene oxide with a C _{_12/18} fatty alcohol in a weight ratio 80: 20

TA5 = adduct of 5 mol on average

Ethylene oxide with a C _{_16/18} fatty alcohol

TA7 = adduct of 7 mol on average

Ethylene oxide with a C _{_16/18} fatty alcohol

TA14 = adduct of 14 mol on average

Ethylene oxide with a C _{_16/18} fatty alcohol

TA20 = adduct of 20 mol on average

Ethylene oxide with a C _{_16/18} fatty alcohol

Claims

1. A process for the preparation of alkyl and / or alkenyl sulfate pastes with improved flowability, characterized in that aqueous pastes of alkyl and / or alkenyl sulfates of the formula (I),

R ¹ -O-SO ₃ X (I) in which R ^{1 is} an alkyl and / or alkenyl radical having 10 to 22 carbon atoms and X is an alkali or alkaline earth metal which has a solids content of 30 to 70% by weight , at least one nonionic surfactant selected from the group formed by a) alkyl and / or alkenyl polyethylglycol ether,

b) alkyl and / or alkenyl polypropylene glycol ether,

c) alkyl and / or alkenyl polypropylene glycol ethylene glycol ether,

d) alkyl and / or alkenyl glycosides,

e) mixed ethers and / or

f) Hydroxy mixed ether is added, the viscosity of the alkyl and / or alkenyl sulfate pastes being at most 15,000 mPa.s at 55 ° C.

2. The method according to claim 1, characterized in that one

Alkyl sulfates of the formula (I) in which R ^{1 is} for one

Alkyl radical with 16 to 18 carbon atoms and X stands for sodium.

3. Process according to claims 1 and 2, characterized in that as component a) alkyl and / or alkenyl polyethylene glycol ether of the formula (II)

R ² -O- (CH ₂ -CH ₂ -O) _n H (II), in which R ^{2 is} a linear or branched alkyl or alkenyl radical having 6 to 22 carbon atoms and n is a number from 2 to 7.

4. Process according to claims 1 and 2, characterized in that as component b) alkyl and / or alkenyl polypropylene glycol ether of the formula (III)

used, in which R ^{3 represents} a linear or branched alkyl or alkenyl radical having 6 to 22 carbon atoms and m represents numbers from 1 to 4.

5. Process according to claims 1 and 2, characterized in that alkyl and / or alkenylpolypropylene glycol-ethylene glycol ether of the formula (IV) as component c)

uses, in which R ^{4 represents} a linear or branched alkyl or alkenyl radical having 6 to 22 carbon atoms, p stands for numbers from 1 to 4 and q stands for numbers from 1 to 10.

6. Process according to claims 1 and 2, characterized in that as component d) alkyl and / or alkenyl glycosides of the formula (V)

R ⁵ uses -O- (G) _x (V), in which R ^{5 represents} an alkyl or alkenyl radical having 6 to 22 carbon atoms, G represents a glycose unit derived from a sugar having 5 or 6 carbon atoms and x stands for a number between 1 and 10.

7. Process according to claims 1 and 2, characterized in that mixed ether of the formula (VI) as component e)

used in which R ^{6 represents} an alkyl or alkenyl radical having 6 to 22 carbon atoms, R ^{7 represents} an alkyl radical with 1 to 4 carbon atoms or a benzyl radical, R ^{8 represents} hydrogen or a methyl group and y represents numbers from 1 to 10.

8. Process according to claims 1 and 2, characterized in that as component f) hydroxy mixed ethers of the formula (VII)

used in which R ^{9 represents} an alkyl radical having 6 to 16 carbon atoms, R ^{10 represents} an alkyl radical with 1 to 4 carbon atoms or a benzyl radical, R ^{11 represents} hydrogen or a methyl group and z represents numbers from 1 to 10.

9. The method according to at least one of claims 1 to 8, characterized in that the nonionic surfactants to the alkyl and / or alkenyl sulfate pastes in amounts of 1 to 15 wt .-% - based on the solids content - added.