EP0642573A1

EP0642573A1 - Powdery surfactants mixture.

Info

Publication number: EP0642573A1
Application number: EP93909976A
Authority: EP
Inventors: Lothar Pioch; Martina Kihn-Botulinski; Wolfgang Seiter
Original assignee: Henkel AG and Co KGaA
Current assignee: Cognis IP Management GmbH
Priority date: 1992-05-21
Filing date: 1993-05-13
Publication date: 1995-03-15
Anticipated expiration: 2013-05-13
Also published as: ES2088673T3; JPH07508773A; EP0642573B1; ATE139559T1; KR100278221B1; JP3565842B2; DE59303031D1; DE4216775A1; WO1993023514A1; KR950701677A

Abstract

In order to obtain loose and pourable, non-lumping powdery products with a process for producing an alkylbenzene sulphonate-free mixture of powdery surfactants by drying aqueous suspensions of the ingredients, while avoiding the danger of spontaneous ignition, in particular of the spray-dryed product, 10 to 40 parts by weight alkylglycoside having the formula: R?1-O(G)n?, in which R?1 represents an alkyl residue having 8 to 22 C atoms, G represents a glycose unit and n is a number between 1 and 10; 5 to 20 parts by weight alkylsulphate having the formula: R?2-OSO3?X, in which R?2 represents an alkyl residue with 10 to 20 C atoms and X represents an alkali-, ammonium- or alkyl- resp. hydroxyalkyl-substituted ammonium ion; and 40 to 80 parts by weight of an inorganic excipient constituted by at least 10 % by weight alkali silicate are mixed with enough water to obtain a fluid mixture that can be pumped at temperatures below 80 C. The weight ratio between the alkylglycoside and the alkylsulphate is comprised between 5:1 and 1:2 and the molar ratio between the SiO2? and the alkali oxide in the alkali silicate amounts to at least 2. The fluid and pumpable mixture is then dehydrated by spray-drying or in a fluidized bed or layer by means of drying gases at temperatures below 250 C. These products are used in particular as loose and pourable precursor mixtures for the production of particulate washing or cleaning agents.

Description

"Powdered surfactant mixture"

The invention relates to powdered, pourable and free-flowing surfactant mixtures which contain alkyl sulfate, alkyl glycoside and inorganic carrier material, a process for their preparation and their use as premixes (compounds) for the production of particulate detergents and cleaning agents.

From the international patent application WO 87/02053 a process for the production of particulate detergents by drying a 40 to 80 percent aqueous slurry is known, which, based on the resulting solid, 2 to 60 wt .-% surfactants, which are at least 0.1 wt. % consist of alkyl glycosides, the total amount of alkyl glycosides being at most 2% by weight, containing 5 to 70% by weight build substances and up to 40% by weight water-soluble fillers. Preferred surfactants used are anionic surfactants, especially those of the alkylbenzenesulfonate type, and nonionic surfactants, especially ethoxylated fatty alcohols. The water is preferably removed from the slurry by spray drying.

US Pat. No. 4,536,319 describes granular detergents which contain alkyl glycosides, water-soluble salts and, if appropriate, water-insoluble powder substances and additional surfactants. The agents described therein contain up to 3% by weight of a special alkali silicate. However, such agents generally have an unsatisfactory flow behavior and tend to clump, particularly during storage.

Modern powder detergents or cleaning agents generally consist of several separately manufactured powder components which, depending on the nature of their ingredients, require different manufacturing processes. A preferred manufacturing process for the surface-active substance-containing component of such agents is because of its relative ease. the spray drying of an aqueous solution or slurry of the ingredients. However, such a process requires a thermal load capacity of the surface-active ingredients, which is ensured when anion surfactants customary to date are used, in particular from the class of alkylbenzenesulfonates.

The use of alkylbenzenesulfonate in washing and cleaning agents has recently been increasingly questioned because of the petroleum base of this surfactant. For example, sulfation products of compounds accessible from renewable raw materials, in particular fatty alcohols, come into consideration as environmentally compatible anionic surfactants with comparable good cleaning properties. However, while aqueous slurries containing alkylbenzenesulfonate can be spray-dried without problems at the temperatures customary in such processes, normally about 250 ° C. to 350 ° C., it has now been found that, under these conditions, aqueous slurries containing the same amount of Contain alkyl sulfates, there is a risk of spontaneous combustion. This problem is exacerbated in the presence of nonionic surfactants in the slurry to be sprayed, but their use in detergents or cleaning agents is often desirable. Such nonionic surfactants include, in particular, alkyl glycosides with long-chain alkyl groups, which have recently been used with preference because of their advantageous properties. Such alkyl glycosides are normally obtained as highly viscous pastes, which means that their use in relatively high concentrations in aqueous slurries intended for spray drying did not appear promising due to the high mechanical stress in such a process.

It was all the more surprising that it is possible to produce flowable and pumpable aqueous slurries from certain amounts of alkyl sulfate, alkyl glycoside and inorganic carrier material, which consists of at least 10% by weight of alkali silicate with a molar ratio S θ2 to alkali oxide above 2, which can be used in a process for producing alkylbenzenesulfonate-free powder-promoting surfactant mixtures by drying while avoiding the aforementioned problems and lead to storage-stable, pourable and free-flowing powder products which, as premixes, so-called Compounds can be used for the production of particulate detergents and cleaners.

The process according to the invention for the preparation of powdered surfactant mixtures free of alkylbenzenesulfonate essentially consists in that 10 to 40 parts by weight of alkylglycoside of the formula I

in which R is an alkyl radical having 8 to 22 carbon atoms, G is a glycose unit and n is a number from 1 to 10,

5 to 20 parts by weight of alkyl sulfate of the formula II,

R ² -0S03X (II)

in which R ^{2 is} an alkyl radical having 10 to 20 C atoms and X is an alkali metal, ammonium or alkyl or hydroxyalkyl-substituted ammonium ion, the weight ratio of alkyl glycoside to alkyl sulfate being 5: 1 to 1: 2, preferably 3 : 1 to 1: 1, and 40 to 80 parts by weight of an inorganic carrier material, which consists of at least 10 wt .-% of alkali silicate with a molar ratio SiO 2 to alkali oxide of at least 2, with so much water that a at temperatures below 80 ° C., the mixture is flowable and pumpable, and the water is withdrawn by spray drying or fluidized bed or fluidized bed drying using drying gases at temperatures below 250 ° C. to such an extent that a powdery, free-flowing product is formed. This is usually the case when the water content in the powder product is not more than 15% by weight, in particular from 5% by weight to 15% by weight. In formulations in which the carrier material binds part of the water as crystal water, the residual water content relates to the free water not bound in the crystal lattice.

Flowable and pumpable in the context of the present invention are those aqueous slurries which can be handled without problems at temperatures below 80 ° C. by means of conventional pumps and pipelines used in spray drying processes. The one in the inventive method Slurries that are used therefore preferably have viscosities in the range from 3000 mPa-s to 15000 mPa-s, measured at 60 ° C. to 75 ° C. by means of conventional viscometers, for example a Brookfield viscometer with spindle No. 3 at 20 revolutions per minute Minute.

The process according to the invention is preferably carried out in such a way that 20 to 30 parts by weight of alkyl glycoside according to formula I, 8 to 15 parts by weight of alkyl sulfate according to formula II and 48 to 68 parts by weight of the inorganic carrier material are mixed with so much water that at least 35 parts by weight .-%, in particular 40 wt .-% to 50 wt .-% water-containing mixture.

The spray-drying of the aqueous slurries takes place in systems usually provided for this purpose, so-called spray towers, in the upper part of which the slurry is sprayed into fine droplets by pressure nozzles, which move under the action of gravity into the lower part of the spray tower and come into contact with hot drying gases which are guided in cocurrent or preferably in countercurrent to the particles to be dried. It is important to ensure that the temperature of the drying gases is not so high that the temperature of the spray-dried particles rises above the self-ignition temperature of these particles. In the context of the invention, this means that the temperature of the drying gases does not exceed a value of 250 ° C. and preferably in the range from 120 ° C. to 240 ° C., in particular from 140 ° C. to 210 ° C. and particularly preferably from 150 ° C is up to 190 ° C., the drying gas temperature being measured at the hottest point of the drying tower, the so-called ring channel. With regard to the temperatures mentioned, the same also applies to the further configuration of the production process according to the invention, fluidized bed or fluidized bed drying.

In the preparation of the slurries leading to the mixtures according to the invention, it is possible to incorporate aqueous, generally 30 to 60 percent by weight alkyl glycoside pastes, as are usually obtained in the course of the alkyl glycosid preparation and, if appropriate, subsequent bleaching . Likewise, the alkyl sulfate component and in particular the carrier component can be used as an aqueous solution or slurry. In order to ensure the easy flow and pumpability of the slurry at temperatures below 80 ° C., it has proven to be advantageous if at least about 35% by weight, preferably 40 to 50% by weight, of water is present in the slurry to be dried . Another advantage of the process according to the invention is the surprisingly low viscosity of the slurries leading to the compounds according to the invention, which is in particular in the range from 3000 mPa-s to 15000 mPa * s at temperatures from 60 ° C. to 75 ° C. against slurries which contain the same amount of alkylbenzenesulfonate instead of alkyl sulfate.

The powdery, free-flowing and free-flowing surfactant mixtures according to the invention produced by the process according to the invention preferably contain 10% by weight to 40% by weight of alkyl glycoside of the formula I,

R ^ OfGJn (I)

in which R ^{1 is} an alkyl radical having 8 to 22 carbon atoms, G is a glycose unit and n is a number from 1 to 10,

5% by weight to 20% by weight of alkyl sulfate of the formula II,

R ² -0S03X (II)

in which R ^{2 is} an alkyl radical having 10 to 20 C atoms and X is an alkali metal, ammonium or alkyl or hydroxyalkyl-substituted ammonium ion, the weight ratio of alkyl glycoside to alkyl sulfate being 5: 1 to 1: 2, in particular 3 : 1 to 1: 1 is 40% by weight to 80% by weight of an inorganic support material which consists of at least 10% by weight, based on the total support material, of alkali silicate with a molar ratio SiO 2 to alkali oxide of at least 2, and up to 15% by weight, in particular 5% by weight to 15% by weight, of water.

The inorganic carrier material present in the compounds according to the invention consists of at least 10% by weight, preferably 20 to 50% by weight. from alkali silicate with a molar ratio SiO 2 to alkali oxide of at least 2, in particular from 2.0 to 3.5 and preferably from 2.5 to 3.5. The preferred alkali metal is sodium. The alkali metal carbonates, alkali metal bicarbonates and alkali metal sulfates and mixtures thereof are particularly suitable as additional water-soluble inorganic support materials which can be used in addition to alkali silicate after drying, the sodium salts also being preferred in these cases. It is also possible to incorporate water-insoluble carrier materials, which include, in particular, layered silicates, for example bentonites or smectites, and aluminosilicates, for example zeolites.

The alkyl glycosides suitable for incorporation into the compounds according to the invention are compounds of the general formula I in which R ^{1 is} an alkyl radical having 8 to 22 carbon atoms, G is a glycose unit and n is a number between 1 and 10. Such alkyl glycosides and their preparation are described, for example, in European patent applications EP 92355, EP 301 298, EP 357 969 and EP 362 671 or US Pat. No. 3547828. The glycoside component ((G) _n in formula I) of such alkyl glycosides is an oligomer or polymer from naturally occurring aldose or ketose monomers, in particular glucose, mannose, fructose, galactose, talose, gulose , Altrose, allose, idose, ribose, arabinose, xylose and lyxose. The oligomers consisting of such glycosidically linked monomers are characterized not only by the type of sugar they contain, but also by their number, the so-called degree of oligomerization. The degree of oligomerization (n in formula I) generally assumes fractional numerical values as the quantity to be determined analytically; it is between 1 and 10, for the alkyl glycosides preferably used below 1.5, in particular between 1.2 and 1.4. The preferred monomer building block is glucose because of its good availability.

The alkyl part (R * in formula I) of the alkyl glycosides contained in the surfactant mixtures according to the invention preferably also originates from easily accessible derivatives of renewable raw materials, in particular from fatty alcohols, although their branched chain isomers, in particular so-called oxo alcohols, are also suitable for the production of alkyl glycosides used can be. Accordingly, the primary alcohols with linear octyl, decyl, dodecyl, tetradecyl, hexadecyl or octa-decyl radicals and mixtures thereof are particularly useful. Particularly suitable alkyl glycosides ent hold a coconut oil fatty, i.e. mixtures essentially Rl = dodecyl and R ^{1 =} tetradecyl .. The alkyl glycosides herstellungsbe¬ dingt small amounts, for example 1, of unreacted fatty alcohol frei¬ em to 2%, does not adversely affect the properties of the compounds produced with it.

Such alkyl glycosides are preferably contained in the compounds according to the invention in amounts of 10% by weight to 40% by weight, in particular 20% by weight to 30% by weight, the weight ratio of alkyl glycoside to alkyl sulfate being 5: 1 to 1: 2, preferably 3: 1 to 1: 1.

Suitable alkyl sulfates for use in the process according to the invention are the compounds of the formula II in which R ^{2 is} an alkyl radical having 10 to 20 C atoms and X is an alkali metal, ammonium or alkyl- or hydroxyalkyl-substituted ammonium ion mean question. The derivatives of fatty alcohols with in particular 12 to 18 carbon atoms and their branched-chain analogs, the so-called oxo alcohols, are particularly suitable. The alkyl sulfates can be prepared in a known manner by reaction of the corresponding alcohol component with a customary sulfating reagent, in particular sulfur trioxide or chlorosulfonic acid, and subsequent neutralization with alkali, ammonium or alkyl or hydroxyalkyl-substituted ammonium bases. Such alkyl sulfates are contained in the compounds according to the invention preferably in amounts of 5% by weight to 20% by weight, in particular 8% by weight to 15% by weight.

In addition, the mixtures according to the invention can contain further surfactants, preferably nonionic surfactants and / or anionic surfactants, and in particular those of the sulfate or sulfonate type, in amounts of preferably not more than 10% by weight, in particular of 1% by weight. % to 5% by weight. The sulfate-type surfactants which can also be used include in particular the sulfated alkoxylation products of the alcohols mentioned, so-called ether sulfates. Such ether sulfates preferably contain 2 to 30, in particular 4 to 10, ethylene glycol groups per molecule. To the Suitable anionic surfactants also include the oc-sulfoesters obtainable by reacting fatty acid esters with sulfur trioxide and subsequent neutralization, in particular those derived from fatty acids with 8 to 22 carbon atoms, preferably 12 to 18 carbon atoms, and linear alcohols with 1 to 6 carbon atoms -Ato¬ men, preferably 1 to 4 carbon atoms, derived sulfonation products as well as those derived from formal saponification of these derivable sulfofatty acids or their salts.

The nonionic surfactants in question include the alkoxylates, in particular the ethoxylates and / or propoxylates of linear or branched-chain alcohols having 10 to 22 carbon atoms, preferably 12 to 18 carbon atoms. The degree of alkoxylation of the alcohols is between 1 and 20, preferably between 3 and 10. They can be prepared in a known manner by reacting the corresponding alcohols with the corresponding alkylene oxides. The derivatives of fatty alcohols are particularly suitable, although their branched chain isomers, in particular so-called oxo alcohols, can also be used to prepare alkoxylates which can be used. Accordingly, the ethoxylates of primary alcohols with linear dodecyl, tetradecyl, hexadecyl or octadecyl radicals and mixtures thereof are particularly useful. Corresponding ethoxylation and / or propoxylation products of alkylamines, vicinal diols and carboxylic acid amides which correspond to the alcohols mentioned with regard to the alkyl part can also be used.

Carrier substances are contained in the powdery mixtures according to the invention in amounts of 40% by weight to 80% by weight, preferably 48% by weight to 68% by weight, it being essential that at least 10% by weight of the carrier material, preferably 20 wt .-% to 50 wt .-%, consist of the alkali silicate mentioned.

In addition, the compounds according to the invention can contain further constituents which are customary in washing and cleaning agents and are stable under the drying conditions. These optional constituents include, in particular, complexing agents for heavy metals, for example aminopolycarboxylic acids and / or polyphosphonic acids, graying inhibitors, for example cellulose ethers, cobuilders, for example polymer polycarbonate acids, foam inhibitors, for example Organopolys loxane or Paraf¬ fine, and optical brighteners, for example stilbene disulfonic acid derivatives. Such additives are preferably present in the powdery surfactant mixtures in amounts not exceeding 5% by weight, in particular 0.5% by weight to 2% by weight.

The powdered surfactant mixtures according to the invention are used in particular as pourable and free-flowing preliminary products (compounds) for the production of particulate detergents or cleaning agents.

For use as premixes for the production of powdered detergents and cleaning agents, the components should have average grain sizes of preferably 0.2 mm to 0.4 mm and should be largely free of particles with diameters of more than 2 mm or less than 50 μm. In this context, largely free means an amount of not more than 0.8% by weight. This limit is normally observed by the compounds according to the invention obtained by spray drying, otherwise particles outside this size range can be removed by simple sieving and returned to the production process. The bulk density of the compounds according to the invention is preferably between 200 and 500 grams per liter and can thus quite deviate from that of the other powdery constituents of a finished washing or cleaning agent, normally without segregation occurring.

The compounds according to the invention are free-flowing, free-flowing powders which do not lose their advantageous properties even after prolonged storage. To produce cleaning agents or detergents, the compounds according to the invention can be mixed in a manner known in principle with other powdery constituents customary in such agents, in particular abrasives, for example quartz powder, bleaching agents, for example perborates or percarbonates, and bleach activators, for example polyacylated alkylenediaes, carboxylic anhydrides or polyacylated polyols. The spraying of liquid, liquefied or dissolved ingredients, for example enzymes, dyes, fragrances or other surfactants, in particular non-ionic surfactants, onto the compounds according to the invention is also possible in a manner known in principle. Examples

example 1

By heating the alkylglycoside component to about 60 ° C., adding it to the aqueous alkyl sulfate solution and adding the other components with stirring, the sodium silicate being added as the last component in the form of an approximately 35 percent by weight waterglass solution , aqueous slurries containing 40 to 44% by weight of water were produced from the raw materials given in Table 1. These slurries, which had the viscosities given in Table 2 at 65 ° C., were heated to temperatures of approximately 60 ° C. to 80 ° C. and sprayed under a pressure of 40 bar in a drying tower, hot air (temperature 150 ° C. up to 190 ° C in the ring channel)

Table 1: Powder composition weight% 1

a) Ci2 / l4-alkyl glucoside, degree of oligomerization 1.4 b) Linear Cχ6 / i8-alkyl sulfate (sulfopone ( ^R ) T, manufacturer Henkel) c) Ratio Siθ2 to a2θ: 3.0 was carried out in countercurrent. The free-flowing powders M1 and M2 characterized in Table 1 by their composition were obtained with average grain sizes around 300 μm, which were free of particles larger than 1.6 mm in diameter, dust fractions from 0.1 to 0.65 % By weight and had bulk densities of 240 to 300 grams per liter.

Table 2: Viscosity [mPa ^«s] of the slurries at 65 ° C measured mit¬ means of Brookfield Viscometer, spindle # 3, 20 rpm.

Claims

1. Powdery, alkylbenzenesulfonate-free pourable and free-flowing Ten¬ sid mixture, which is obtained by drying a pourable aqueous mixture of its components, and the

10% by weight to 40% by weight of alkyl glycoside of the formula I,

^ OCGJn (I)

5% by weight to 20% by weight of alkyl sulfate of the formula II,

R ² -0S03X (II)

in which R ^{2 is} an alkyl radical having 10 to 20 C atoms and X is an alkali, ammonium or alkyl or hydroxyalkyl-substituted ammonium ion, the weight ratio of alkyl glycoside to alkyl sulfate being 5: 1 to 1: 2, in particular 3 : 1 to 1: 1 is 40% by weight to 80% by weight of an inorganic carrier material which consists of at least 10% by weight, based on the total carrier material, of alkali silicate with a molar ratio SiO 2 to alkali oxide of at least 2 exists, and contains up to 15 wt .-% water.

2. Surfactant mixture according to claim 1, characterized in that it contains 20 wt.% To 30 wt.% Alkyl glycoside according to formula I, 8 wt.% To 15 wt.% Alkyl sulfate according to formula II, 48 to 68 wt. % of inorganic carrier material, not more than 10% by weight, in particular from 1% by weight to 5% by weight, of additional anionic and / or nonionic surfactant and 5% by weight to 15% by weight of water.

3. surfactant mixture according to claim 1 or 2, characterized in that the inorganic carrier material to 20 wt .-% to 50 wt .-% of alkali metal Kat with a molar ratio SiO 2 to alkali oxide of at least 2, in particular from 2.0 to 3.5, exists.

4. A surfactant mixture according to one of claims 1 to 3, characterized in that the alkyl glycoside of the formula I is an alkyl glucoside and has a degree of oligomerization n below 1.5, in particular from 1.2 to 1.4.

5. surfactant mixture according to any one of claims 1 to 4, characterized gekennzeich¬ net that the alkyl sulfate of formula II has an alkyl radical R ² having 12 to 18 carbon atoms.

6. Use of a powdered surfactant mixture according to one of claims 1 to 5 as a pourable and pourable premix for the production of particulate detergents or cleaning agents.

7. A process for the preparation of alkylbenzenesulfonate-free powdered surfactant mixtures by drying flowable, aqueous, surfactant-containing mixtures, characterized in that

10 to 40 parts by weight of alkyl glycoside of the formula I,

R ^ G) ,, (I)

in which R 1 is an alkyl radical having 8 to 22 carbon atoms, G is a glycose unit and n is a number from 1 to 10,

5 to 20 parts by weight of alkyl sulfate of the formula II,

R ² -0S03X (II)

in which R ^{2 is} an alkyl radical having 10 to 20 C atoms and X is an alkali, ammonium or alkyl or hydroxyalkyl-substituted ammonium ion, the weight ratio of alkyl glycoside to alkyl sulfate being 5: 1 to 1: 2, and

40 to 80 parts by weight of an inorganic carrier material, which consists of at least 10 wt .-% of alkali silicate with a molar ratio SiO 2 to alkali oxide of at least 2, mixed with so much water that a mixture which is flowable and pumpable at temperatures below 80 ° C. is obtained, and this removes the water by spray drying using drying gases at temperatures below 250 ° C. to such an extent that a powdery, free-flowing product is formed.

8. The method according to claim 7, characterized in that 20 to 30 parts by weight of alkyl glycoside according to formula I, 8 to 15 parts by weight of alkyl sulfate according to formula II and 48 to 68 parts by weight of the inorganic carrier material are mixed with so much water that an at least 35 parts by weight .-%, in particular 40 wt .-% to 50 wt .-% water-containing mixture.

9. A process for the preparation of alkylbenzenesulfonate-free powdered surfactant mixtures by drying flowable, aqueous, surfactant-containing mixtures, characterized in that

10 to 40 parts by weight of alkyl glycoside of the formula I,

Rl-0 (G) _n (I)

5 to 20 parts by weight of alkyl sulfate of the formula II,

R ² -0S03X (II)

40 to 80 parts by weight of an inorganic carrier material, which consists of at least 10 wt .-% of alkali silicate with a molar ratio SiO 2 to alkali oxide of at least 2, mixed with so much water that a flowable and pumpable mixture at temperatures below 80 ° C is formed, and this removes the water by fluidized bed drying using drying gases at temperatures below 250 ° C. to such an extent that a powdery, free-flowing product is formed. 10. The method according to any one of claims 7 to 9, characterized in that the weight ratio of alkyl glycoside to alkyl sulfate is 3: 1 to 1: 1.

11. The method according to any one of claims 7 to 10, characterized in that the inorganic carrier material to 20 to 50 wt .-% of Alkalisi¬ likat with a molar ratio SiO 2 to alkali oxide of at least 2, in particular from 2.0 to 3.5, consists and in addition to the alkali silicate contains an alkali carbonate, alkali bicarbonate, alkali sulfate, layered silicate or aluminosilicate or a mixture of these.

12. The method according to any one of claims 7 to 11, characterized in that drying gases with temperatures of 120 ° C to 240 ° C, in particular from 140 ° C to 210 ° C are used.

13. The method according to any one of claims 7 to 12, characterized in that the aqueous mixture to be dried has a viscosity of 3000 mPa ^« s to 15000 mPa * s, measured at 60 ° C to 75 ° C.

14. Use of a powdered surfactant mixture, produced by the process according to one of claims 7 to 13, as a pourable and pourable premix for the production of particulate detergents or cleaning agents.