EP0415988A1

EP0415988A1 - Anti-froth alkyl polyglycol ethers for detergents (i)

Info

Publication number: EP0415988A1
Application number: EP89906075A
Authority: EP
Inventors: Karl-Heinz Schmid; Gilbert Schenker
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1988-05-27
Filing date: 1989-05-18
Publication date: 1991-03-13
Also published as: ZA894027B; WO1989011525A1; EP0343503A1; DE3818062A1; JPH03504613A

Abstract

Des éthers de polyéthylène-glycol d'alkyle ou d'alkényle de formule générale I: R1-O-(CH2CH2O)n-R2 dans laquelle R1 est un résidu alkyle et/ou alkényle à chaîne droite ou ramifié avec 8 à 18 atomes de C, R2 est un résidu alkyle avec 8 à 14 atomes de C, et n est un nombre compris entre 20 et 40, sont utilisés comme constituants tensioactifs faiblement moussants et/ou antimousse dans des produits de rinçage et de lavage aqueux, notamment des agents mouillants pour laver la vaisselle à la machine dans des applications domestiques et industrielles, avec un effet mouillant particulièrement élevé sur les plastiques durs. Sont également décrits des mélanges de tensioactifs à base de composés de formule générale (I) en mélange avec d'autres éthers de polyéthylène-glycol d'alkyle ou d'alkényle non ioniques de formules (II) à (IV) avec les constituants B-1 à B-3, ainsi que des produits de rinçage et/ou de lavage faiblement moussants mettant en oeuvre ces tensioactifs ou ces mélanges de tensioactifs, et un procédé pour leur fabrication.Alkyl or alkenyl polyethylene glycol ethers of the general formula I: R1-O- (CH2CH2O) n-R2 wherein R1 is a straight chain or branched alkyl and / or alkenyl residue with 8 to 18 carbon atoms. C, R2 is an alkyl residue with 8 to 14 C atoms, and n is a number between 20 and 40, are used as low foaming and / or anti-foaming surfactant constituents in aqueous rinses and washes, especially agents wetting agents for machine washing in domestic and industrial applications, with a particularly high wetting effect on hard plastics. Also disclosed are mixtures of surfactants based on compounds of general formula (I) mixed with other nonionic alkyl or alkenyl polyethylene glycol ethers of formulas (II) to (IV) with constituents B -1 to B-3, as well as low-foaming rinsing and / or washing products using these surfactants or these mixtures of surfactants, and a process for their manufacture.

Description

Foam-pressing alkyl polyglycol ethers for cleaning agents (I)

The invention relates to the novel use of low-foam or foam-suppressing and biodegradable surfactants and surfactant mixtures in detergents and cleaning agents, in particular rinse aid, for machine dishwashing with good wetting and draining action on hard surfaces. The invention gives particular advantages when cleaning molded parts made of plastics.

In the case of automatic dishwashing, two rinse cycles with different types of products, usually separated by intermediate rinse cycles with pure water, are used. In the actual cleaning cycle, alkaline reacting agents are used to detach and emulsify the food residues. In the so-called rinse or rinse cycle, however, special rinse aid is used. These are not cleaning agents, but should have good wetting power and reduce the surface tension of the rinse water to such an extent that it runs off the dishes like a film and does not leave any visible residues, such as lime stains or other soiling. Because of the strong movement of liquors in household and commercial dishwashers, the rinse aid must be as low-foaming as possible. Since the usual anionic wetting agents, such as higher molecular weight alkyl sulfates or alkyl or alkylarylsulfoates, are known to have a strong tendency to foam and are therefore not suitable for this use, nonionic surfactants based on ethylene oxide adducts on fatty alcohols, alkylphenols or polypropylene glycols of relatively high molecular weights are preferred in practice .

In practice, however, it has been shown that these products are usually still not sufficiently low in foam in the concentration ranges required for a sufficient wetting effect. They lead easily, especially in commercial dishwashers with very high water circulation and the usual recirculation of the rinse liquor, which is around 80 ° C hot, into the main cleaning cycle with approx. 50 to 70 ° C and alkaline detergent and into the dirt pre-cleaning zone, which is only 40 ° C warm, with all food soiling mechanical disturbances due to excessive and stable foaming. The same difficulties can also occur in household dishwashers. It is therefore usually necessary to add foam detergent to the rinse aid even when using relatively low-foaming ethylene oxide adducts. Such nonionic alkoxylation products which are sparingly water-soluble at rinse temperatures, such as, for example, ethylene oxide adducts with higher alcohols, alkylphenols or amines with a low degree of ethoxylation or corresponding adducts of ethylene oxide and propylene oxide or propylene oxide and ethylene oxide. However, such products have no wetting effect at application temperatures and therefore pose a burden on the rinse aid. From DE-OS 35 30 303 and DE-OS 35 12 120 it is also known that alkyl polyethylene glycol ethers of the general formula

R ¹ -O- (CH ₂ CH ₂ O) _{m / n} -R ²

in the

R ^{1 is} a straight-chain or branched alkyl or alkenyl radical having 8 to 18 carbon atoms,

R ^{2 is} an alkyl radical with 4 to 8 carbon atoms, n is a number from 7 to 16 and m is a number from 17 to 23, with a cloud point of less than 45 ° C. are low-foam, biodegradable surfactants which, when used as rinse aid for Machine dishwashing has an excellent wetting and draining effect compared to glasses, cutlery and porcelain plates.

However, it is still particularly difficult to wet plastic dishes, e.g. made of polypropylene or polycarbonate. On such plastic tableware, e.g. made of the plastic "Makroion", low-foaming surfactants have an insufficient wetting ability. If, on the other hand, good wetting surfactants such as fatty alcohol ethoxylates are used, they do not meet the technically necessary requirements for low foam.

It has now surprisingly been found that significant improvements can also be achieved here by using selected surfactants or surfactant mixtures of the type described below.

Accordingly, the object of the invention is in a first embodiment the use of closed groups Alkyl or alkenyl polyethylene glycol ethers of the general formula (I)

R ₁ -O- (CH ₂ CH ₂ O) _n -R ₂ (I)

in the

R _{1 is} a straight-chain or branched alkyl and / or

Alkenyl radical with 8 to 18 carbon atoms, R _{2 is} an alkyl radical with 8 to 14 carbon atoms and n is a number from 20 to 40, as low-foaming and / or foam-suppressing surfactant component in aqueous dishwashing detergents and cleaning agents with a particularly high wetting action compared to solid plastics .

A particularly important area of use for these nonionic surfactant components of the general formula (I) in the sense of the invention is the area of rinse aids already mentioned at the beginning with improved wetting action compared to solid plastic surfaces, but at the same time less or less foam formation.

Compounds of the general formula (I) which are preferably used according to the invention contain, as the radical R _2, an alkyl radical having 8 to 10 and in particular 10 carbon atoms. The preferred value for n is a number from 25 to 35.

In a further embodiment of the invention, selected surfactant mixtures are described, each with the use of surfactant components of the general formula (I), which are distinguished by particularly good properties in the specified field of use. In the surfactant combinations described in detail below, the compounds of the general formula (I) are referred to as component (A), which are mixed with one or more of the Ten sid components B-1 to B-3 are used. These mixture components B-1 to B-3 correspond to the compounds of the general formulas (II), (III) and (IV) given below.

In the embodiment of the invention concerned here, surfactant mixtures for use in detergents and cleaning agents, in particular in rinse aid with a high wetting action compared to solid plastics, but with reduced foaming, are described, which are characterized by the content of

(A) alkyl or alkenyl polyethylene glycol ethers of the general formula (I) in admixture with

(B) at least one of the following nonionic alkyl or alkenyl polyethylene glycol ether surfactant components of the general formulas (II) to (IV), in which in each case R _{1 has} the meaning given for the formula (I),

(B-1) compounds of the general formula (II)

m the

R _{3 is} a methyl or ethyl radical and a is a number from 2 to 6 and b is a number from 3 to 7,

(B-2) compounds of the general formula (III)

R ₁ -O- (CH ₂ CH ₂ O) _c -R ₄ (III) in which R _{4 is} an alkyl radical with 4 to 8 C atoms and c is a number from 7 to 12,

(B-3) compounds of the general formula (IV)

R ₁ -O- (CH ₂ CH ₂ O) _d -H (IV)

in which d is a number from 20 to 50 and preferably from 25 to 35.

In an important embodiment, the invention relates to surfactant mixtures of the type specified, which are characterized in that they are mixtures of alkyl or alkenyl polyglycol ethers of the general formulas (I) and (II) in a mixing ratio of 50:50 to 20:80 parts by weight (I): (II) included.

It has proven particularly expedient to use the compounds of the general formulas (I) used according to the invention as mixture component (A) in admixture with the non-end-capped polyethylene glycol ethers of the general formula (IV) - component B-3. In the preferred embodiment, the mixture components B-1 and / or B-2 are also additionally present in the surfactant mixture according to the invention or used according to the invention. A particularly preferred object of the invention accordingly contains the nonionic surfactant components in the following proportions 10 to 40% by weight, preferably 15 to 25% by weight, of compounds of the general formula (I)

10 to 40% by weight, preferably 15 to 30% by weight, of compounds of the general formula (IV)

20 to 80 wt .-%, preferably 45 to 65 wt .-% of compounds of general formulas (II) and / or

(III).

Mixture components from the class of cosurfactants B-1 to B-3 which are particularly preferred are the following types of compounds:

Compounds of the general formula (II): C12 / 14-3EO-6PO Compounds of the general formula (III): C12 / 18-10EO-C4 Compounds of the general formula (IV): C12 / 14-30EO

Finally, in a further embodiment, the invention relates to low-foaming detergents and / or cleaning agents, in particular rinse aids for machine dishwashing in the home and business, with improved wetting properties compared to plastics based on a preferably aqueous solution of nonionic surfactants from the class of alkyl and / or alkenyl Polyethylene glycol ether, where, in addition to the surfactants or surfactant mixtures described above, these agents can, if desired, contain customary mixture components, such as solubilizers, hydrotropic substances, agents for preventing limescale, fragrances and / or dyes and, if appropriate, further auxiliaries. Aqueous rinse aids of this type in particular are described in principle in the publications DE-OS 35 12 120 and 35 30 303 mentioned at the outset. In order to complete the disclosure of the invention, the essential details are listed again below. The alkyl polyethylene glycol ethers used according to the invention are used in the rinse aids in a concentration of 5 to 80, preferably 25 to 50% by weight, and preferably in an aqueous solution.

To achieve sufficient temperature stability, however, it may be useful to add solubilizing substances such as mono- or polyvalent alkanols (e.g. ethanol, propanol, isopropanol, ethylene glycol, propylene glycol) - preferably in amounts of about 5 to 20% by weight, based on the total rinse aid.

Hydrotropic substances, such as the alkali metal salts of low molecular weight alkylbenzenesulfonic acids, sodium cumene sulfonate, sodium xylene sulfonate or sodium toluenesulfonate, are also effective.

Depending on the cloud point of the surfactant and the desired storage stability, the amounts of the solubilizing and / or hydrotropic substances can be between 0 and 40% by weight, based on the total rinse aid.

In addition, to prevent limescale deposits on the dishes when using non-softened water in the rinse cycle, an additional 0 to 40, preferably 10 to 35% by weight, based on the total rinse aid, of complexing agents, such as, for example, citric acid, tartaric acid, glycolic acid and / or commercially available technical mixture

Succinic acid, glutaric acid and adipic acid (Sokalan DCS ^(R) from BASF).

Complexing agents which have threshold-effective properties, such as, for example, 2-phosphonobutane-1,2,4-tricarboxylic acid (Bayhibit AM ^(R) ), can also be used, provided they are physiologically harmless. Here, the application concentration ions are also lower and are 0 to 10, preferably 2 to 7 wt .-%, based on the total rinse aid.

Furthermore, customary colorants, fragrances and preservatives can be added in the customary manner for use in rinse aids.

As a starting material for the preparation of the polyglycol ethers of the general formula (I), for example fatty alcohols such as n-octanol, n-decanol, n-dodecanol, n-tetradecanol, n-hexadecanol, n-octadecanol and / or unsaturated components such as n-octadecene 9,10-ol (oleyl alcohol) but also alcohols of the stated carbon number of other origin, for example oxo alcohols, can be used individually or in a mixture.

To prepare the alkyl polyethylene glycol ethers of the general formula (I) to be used according to the invention, the fatty alcohols described above are advantageously etherified with ethylene oxide in a moiety ratio of 1:20 to 1:40 and in particular in molar ratios of about 1:25 to 1:35 then at least some of the hydroxyl groups present in the reaction product obtained. The reaction with ethylene oxide takes place under the known alkoxylation conditions, preferably in the presence of suitable alkaline catalysts. The etherification of the free hydroxyl groups is preferably carried out under the known conditions of Williamson's ether synthesis with straight-chain and / or branched C ₈ to C ₁₄ alkyl halides, the use of appropriate alkyl chlorides being particularly suitable. It may be expedient to use an approximately stoichiometric ratio of alkyl halide and alkali to about twice the stoichiometric excess, so that molar ratios of the ethoxylated alcohol to the alkyl halide in the range from about 1.0: 0.9 to 1.0: 2.0 are particularly suitable.

Finally, the invention relates in a further embodiment to a process for the production of low-foaming rinse aids for machine dishwashing in the home and business, this process being characterized in that surfactants or surfactant mixtures of the stated type are prepared and the reaction product obtained with water and / or mixes the other auxiliaries mentioned.

Examples

The following examples summarize comparative examples relating to the prior art and examples in the sense of the inventive action. The tested agents are tested on the one hand with regard to their wetting capacity compared to a plastic surface and on the other hand with regard to the tendency to foam or the anti-foam effect. The following applies to these tests:

Determination of network assets

The wetting capacity of the surfactant mixtures listed in the examples was determined using the following method:

3 liters of water with a water hardness of 16 ° dH and a temperature of 65 ° C are poured into a plastic tub 40 cm long, 28 cm wide and 12 cm high. 2.4 g of the surfactant mixtures given in the examples are dissolved in this amount of water. Before this liquid cools down, a Makrolon plastic plate with a diameter of 24 cm is completely immersed in this solution and left in this surfactant solution for about 30 seconds. The plate is then pulled out and already visually assessed when it is pulled out. It is evaluated how quickly the water film still adhering to the plastic plate when it is pulled out of the cleaning solution tears open, which leads to dry spots on the plate being visible. If no dry spots can be seen 10 seconds after the plate has been pulled out, i.e. if the surface of the plate is still 100% covered with water film after this time, the evaluation number is 100%. A rating of 60% means here conditions that after this time the surface of the plate is only 60% covered by a film of water. The higher this rating number for one of the surfactant mixtures given in the examples, the better its wetting power.

Testing the anti-foam effect

The foam-suppressing effect of the antifoams listed in the examples was tested using the following test method:

In 500 ml of water with a water hardness of 16 ° dH, 1 g of whole egg is whisked homogeneously and 1.5 g of the dishwasher cleaner "Topmat intensive" (brand name from Henkel) is dissolved. This liquid is then poured into a double-walled measuring cylinder of 2,000 ml and heated to 40 ° C. After the test temperature has been reached, 0.25 g of the low-foam surfactant mixture given in the examples is added to this amount of liquid. With the help of a laboratory hose pump, this solution is sucked from the bottom of the measuring cylinder with a glass tube. The liquid is returned to the measuring cylinder via a second tube, the lower end of which ends at the height of the upper edge of the measuring cylinder. The liquid is pumped around at a rate of 4 1 / min and falls back into the measuring cylinder. This pumping around the liquid creates foam. After 1, 2, 3, 4, 5, 7 and 10 min pumping time, the volumes given in the examples are read, which have formed from foam and liquid after these times. Comparative examples

Coconut alcohol is a linear saturated fatty alcohol with a C chain distribution of approx. 70% C ₁₂ and 30% C ₁₄ .

Comparative Example 1:

The surfactant mixture consists of

50% by weight coconut alcohol 3EO-6PO 50% by weight coconut alcohol 5EO-4PO

Valuation number network assets: 30%.

Foam development

Minutes volume (ml)

1,500

2 520

3 520

4 5.20

5 540

7,560

10 580

Comparative Example 2:

The surfactant mixture consists of

50 wt% coconut alcohol-5EO-4PO

50% by weight R- (oCH ₂ CH ₂ ) ₁₀ -OC ₄ E ₉ (R = C _12/18 )

Valuation number network assets: 50% Foam development

Minutes volume (ml)

1,500

2,500 3,500

4 520

5 520

7 520

10 520

Comparative Example 3:

The surfactant mixture consists of

60% R- (OCH ₂ CH ₂ ) ₁₀ -oC ₄ H ₉ (R = C _12/18 )

20% coconut alcohol-23EO

20% R- (OCH ₂ CH ₂ ) ₇ -OC ₄ H ₉ (R = C _12/18 )

Valuation number network assets: 90%

Foam development

Minutes volume (ml)

1,680

2,700

3,720

4,740

5 740

7 760

10 780 Comparative Example 4:

The surfactant mixture consists of 75% R- (OCH ₂ CH ₂ ) ₁₀ -OC ₄ H ₉ C _12/18 ) 25% coconut alcohol-23EO

Valuation number network assets: 100%

Foam development

Minutes volume (ml)

1,740

2,800

3 920

4 1 040

5 1 300

7 1 620

10 over foamed

(more than 2,000)

Comparative Example 5:

The surfactant mixture consists of

70% coconut alcohol-3EO-6PO 30% coconut alcohol-30EO

Valuation number network assets: 80% Foam development

Minutes volume (ml)

1,760 2,850

3,950

4 1 130

5 1 450

7 1 860

10 over foamed

(more than 2,000)

Examples according to the invention

Example 1:

The surfactant mixture consists of

57% coconut alcohol-3EO-6PO 23% R- (OCH ₂ CH ₂ ) ₃₀ -OC ₁₀ H ₂₁ (R = coconut alcohol) 20% coconut alcohol-23EO

Valuation number network assets: 100%

Foam development

Minutes volume (ml)

1,500

2,500

3,500

4,500

5,500

7 520

10 540 Example 2:

The surfactant mixture consists of

55% coconut alcohol-4EO-5PO

25% R- (OCH ₂ CH ₂ ) ₄₀ -OC _12/14 H _25/29 (R = C _12/18 )

20% coconut alcohol-30EO

Valuation number network assets: 100%

Foam development

Minutes volume (ml)

1,500

2,500

3,500

4,500

5,500

7 520

10 520

Example 3:

The surfactant mixture consists of

50% R- (OCH ₂ CH ₂ ) ₁₀ -OC ₄ H ₉ (R = C _12/18 ) 30% R- (OCH ₂ CH ₂ ) ₃₀ -OC _12/14 H _25/29 20% coconut alcohol-30EO

Valuation number network assets: 100

Foam development

Minutes volume (ml)

1 520

2 520

3 520

4 520

5 520

7 520

10 520

Claims

Patent claims

1. Use of end-capped alkyl or alkenyl polyethylene glycol ethers of the general formula "(I)

R ₁ -O- (CH ₂ CH ₂ O) _n -R ₂ (I)

in the

R _{1 is} a straight-chain or branched alkyl and / or

2. Embodiment according to claim 1, characterized in that compounds of the general formula (I) are used in which R _{2 is} an alkyl radical having 8 to 10, in particular having 10 carbon atoms, and n is a number from 25 to 35.

3. Containing surfactant mixtures for use in detergents and cleaning agents, in particular rinse aids, with a high wetting action compared to solid plastics, but with reduced foaming

(B) at least one of the following nonionic alkyl or alkenyl polyethylene glycol ether surfactant components of the general formulas (II) to (IV), in which in each case R _{1 has} the meaning given for the formula (I), (B-1) compounds of the general formula (II)

R ₁ -O- (CH ₂ CH ₂ O) - (CH ₂ -CH-O) _b -H (II)

in the

(B-2) compounds of the general formula (III)

R ₁ -O- (CH ₂ CH ₂ O) _c -R ₄ (III)

in which R _{4 is} an alkyl radical with 4 to 8 C atoms and c is a number from 7 to 12,

(B-3) compounds of the general formula (IV)

R ₁ -O- (CH ₂ CH ₂ O) _d -H (IV)

in which d is a number from 20 to 50 and preferably from 25 to 35.

4. Surfactant mixtures according to claim 3, characterized in that they contain mixtures of alkyl or alkenyl polyglycol ethers of the general formulas (I) and (II) in a mixing ratio of 50:50 to 20:80 parts by weight (I): (II) contain.

5. Surfactant mixtures according to claims 3 and 4, characterized in that they contain the nonionic surfactant components in the following proportions:

10 to 40% by weight, preferably 15 to 25% by weight, of compounds of the general formula (I)

(III).

.

6. Low-foam detergents and / or cleaning agents, in particular rinse aids for machine dishwashing in households and businesses with improved wetting properties compared to plastics based on a preferably aqueous solution of nonionic surfactants from the class of alkyl and / or alkenyl polyethylene glycol ethers, if desired containing solubilizers, hydrotropic substances , Agents for preventing limescale, fragrances and / or substances and optionally further auxiliaries, characterized in that they contain surfactant mixtures according to Claims 3 to 6 in amounts of about 5 to 80% by weight, in particular in amounts of about 15 to 50% by weight .-% contain.

7. Low foam detergent and / or cleaning agent according to claim

6, characterized in that they contain complexing agents such as citric acid, tartaric acid, glycolic acid and / or technical mixtures of succinic acid, glutaric acid and adipic acid in amounts of 0 to 40% by weight, preferably 10 to 35% by weight and / or threshold effective complexing agents, such as 2-phosphonobutane 1,2,4-tricarboxylic acid, in amounts of 0 to 10 wt .-%, preferably from 2 to 7 wt .-%, wt .-% each based on the total rinse aid.

8. Low-foam detergent and / or cleaning agent according to claims 6 and 7, characterized in that they contain cumene sulfonate in amounts of 5 to 20 wt .-%, based on the total rinse aid.

9. Low-foam detergent and / or cleaning agent according to claims 6 and 7, characterized in that they contain low alcohols such as ethanol and / or isopropanol in amounts of 5 to 20 wt .-%, based on the total rinse aid.

10. A process for the preparation of low-foaming rinse aid for machine dishwashing in the household and commercial, characterized in that alkanols or alkenols of the formula R ₁ -OH, in which R _{1 is} a straight-chain or branched alkyl or alkenyl radical with 8 to 18 C- Atoms means ethoxylated with ethylene oxide in a molar ratio of 1:20 to 1:40 and in particular 1:25 to 1:35 in the presence of alkaline catalysts, then etherifying the free hydroxyl groups with straight-chain or branched C ₈ to C ₁₄ alkyl halides, preferably alkyl chlorides and in particular works with molar ratios of the ethoxylated alcohol to the alkyl halide in the range from 1.0: 0.9 to 1.0: 2.0 and mixes the reaction product obtained with water and / or the other auxiliaries mentioned.