DE3818062A1 - FOAMING ALKYL POLYGLYCOLETHER FOR CLEANING AGENT (I) - Google Patents

Description

The invention relates to the novel use of low-foam or foam-depressing and biodegradable surfactants and Surfactant mixtures in rinsing and cleaning agents, in particular Rinse aid for machine dishwashing with Good wetting and drainage effect against hard surfaces. The invention gives particular advantages when cleaning of molded parts made of plastics.

Machine dishwashing generally involves two usually separated by intermediate rinses with pure water Rinses applied with various products. in the actual cleaning cycle come to the replacement and emulsification the food particles alkaline reacting agents are used. In the so-called after-rinse or even rinse cycle are there used against special rinse aid. These are not Detergents, but should have a good wetting capacity and the surface tension of the rinsing water so far minimize that this runs like a film from the dishes and no visible residue, such as limescale or other ver Dirt leaves.  

Because of the strong fleet movement in household and commercial Dishwashers need the rinse aid as possible be low in foam. Since the usual anionic wetting agents, such as higher molecular weight alkyl sulfates or alkyl or alkyl arylsulfonates known to have a strong foam tendency and therefore are not useful for this use, you pull in practice nonionic surfactants based on Ethylenoxidaddukten to fatty alcohols, alkylphenols or poly propylene glycols of higher molecular weights.

In practice, however, it has been shown that these products in the necessary for a sufficient network effect Concentration areas usually not sufficiently low in foam are. They lead, especially in commercial dishwashers with very high water circulation and the usual recycling the about 80 ° C hot rinse liquor in the main cleaning cycle with approx. 50 to 70 ° C and alkaline cleaning agent and in the only 40 ° C warm Schmutzvorabraumzone with still all food stains, easy to mechanical Disturbances due to excessive and stable foaming. However, the same difficulties can also be found in Household dishwashers occur. One is therefore mostly forced, even when using relatively low-foaming Ethylenoxidaddukte Add foam suppressant to the rinse aid. When such come nonionic alkoxylation products, which Rinsing temperatures are slightly water-soluble, into consideration, such as z. B. ethylene oxide adducts to higher alcohols, alkylphenols or Amines with a low degree of ethoxylation or equivalent Adducts of ethylene oxide and propylene oxide or propylene oxide and ethylene oxide. However, such products have application Temperatures no network effect and therefore a burden of the rinse aid.  

From DE-OS 35 30 303 and DE-OS 35 12 120 is still it is known that alkylpolyethylene glycol ethers of the general For mel

R¹-O- (CH₂CH₂O) _{m / n} -R²

in the
R¹ represents a straight-chain or branched alkyl or alkenyl radical having 8 to 18 C atoms,
R 2 is an alkyl radical having 4 to 8 C atoms,
n is a number from 7 to 16 and
m is a number from 17 to 23
mean, with a cloud point of less than 45 ° C low-foam, biodegradable surfactants represent that have an excellent wetting and drainage action when compared to glasses, cutlery and porcelain plates when used as a rinse aid for machine dishwashing.

However, the wetting of Plastic dishes z. B. polypropylene or polycarbonate. On such plastic dishes, z. B. from the plastic "Makrolon", low-foaming surfactants have insufficient content networking assets. On the other hand, if one uses well-wetting surfactants like fatty alcohol ethoxylates, they do not match the technically necessary requirements for their low foaming.

It has now surprisingly been found that by use selected surfactants or surfactant mixtures in the following described here also significant improvements can be adjusted.

The invention accordingly is in a first Embodiment the use of end-capped  Alkyl or Alkenylpolyethylenglykolethern the general Formula (I)

R₁-O- (CH₂CH₂O) _n -R₂ (I)

in the
R₁ is a straight-chain or branched alkyl and / or alkenyl radical having 8 to 18 C atoms,
R₂ is an alkyl radical having 8 to 14 C atoms and
n is a number from 20 to 40
mean, as a low-foaming and / or foam-damping surfactant component in aqueous rinsing and cleaning agents with in particular high wetting action over solid plastics.

A particularly important application within the meaning of the invention for these nonionic surfactant components of the general Formula (I) is the area of Rinse aid with improved wetting action over solid Plastic surfaces, but at the same time less or ver reduced foaming.

Compounds of general formula (I) which are preferably used according to the invention contain, as radical R₂, an alkyl radical having 8 to 10 and in particular 10 C atoms. The preferred value for n is a number from 25 to 35.

In a further embodiment of the invention are - respectively with the concomitant use of surfactant components of general formula (I) - selected surfactant mixtures, which is characterized by particularly good properties on the specified Field of application. In the following in the individual described surfactant combinations are the compounds of the general formula (I) as component (A), in mixture with one or more of the Ten  sidkomponenten B-1 to B-3 are used. This mix Components B-1 to B-3 correspond to those in the following specified compounds of the general formulas (II), (III) and (IV).

In the embodiment of the invention concerned here are Surfactant mixtures for use in dishwashing detergents and cleaning agents, especially in rinse aids with high wetting effect compared to solid plastics, but with reduced Described foaming, which are characterized by the Salary

• (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 each R₁ is the meaning given for the formula (I) Has,
• (B-1) Compounds of General Formula (II) in the
  R₃ is a methyl or ethyl radical and
  a is a number from 2 to 6 and
  b is a number from 3 to 7
  mean,
• (B-2) Compounds of general formula (III) R₁-O- (CH₂CH₂O) _c -R₄ (III) in the
  R₄ is an alkyl radical having 4 to 8 carbon atoms and
  c is a number from 7 to 12
  mean,
• (B-3) Compounds of the general formula (IV) R₁-O- (CH₂CH₂O) _d -H (IV) in the
  d is a number from 20 to 50 and preferably from 25 to 35.

In an important embodiment, the invention relates Surfactant mixtures of the type indicated, characterized are that they are mixtures of alkyl or Alkenylpolyglykolethern of the general formulas (I) and (II) in the mixing ratio from 50:50 to 20:80 parts by weight (I): (II) ent hold.

It has proved to be particularly useful according to the invention compounds used as mixture component (A) of the general formulas (I) in admixture with the non-end-capped polyethylene glycol ethers of general formula (IV) - component B-3 - use. there are in the preferred embodiment in the invention or surfactant mixture used according to the invention additionally also the mixture components B-1 and / or B-2 present. A particularly preferred subject of the invention accordingly, the nonionic surfactant components in the the following proportions

10 to 40% by weight, preferably 15 to 25% by weight, of compounds of the general formula (I)
From 10 to 40% by weight, preferably from 15 to 30% by weight, of compounds of the general formula (IV)
From 20 to 80% by weight, preferably from 45 to 65% by weight, of compounds of the general formulas (II) and / or (III).

In each case, particularly preferred mixture components from the class of cosurfactants B-1 to B-3 are the following types of compounds:
Compounds of general formula (II): C12 / 14-3EO-6PO
Compounds of general formula (III): C12 / 18-10EO-C4
Compounds of general formula (IV): C12 / 14-30EO

Finally, the invention relates to a further embodiment low-foaming rinsing and / or cleaning agents, in particular Rinse aid for machine dishwashing in households and businesses with improved network properties compared to plastics based on a preferably aqueous Solution of nonionic surfactants from the class of alkyl and / or Alkenyl polyethylene glycol ethers, these agents in addition the surfactants or surfactant mixtures described above if desired, customary mixture components, such as solubilizers, hydrotropic substances, means of prevention the limescale, fragrances and / or dyes and optionally may contain other auxiliaries. In particular Aqueous rinse aids of this type are mentioned in the beginning Publications DE-OSs 35 12 120 and 35 30 303 in principle portrayed. To complete the invention disclosure are the essential details in the following listed again.  

The alkylpolyethylene glycol ethers used according to the invention be in the rinse aid at a concentration of 5 to 80, preferably 25 to 50 wt .-% and preferably used in aqueous solution.

To achieve a sufficient temperature stability can but it would be useful to still solution-mediating substances, such as B. mono- or polyhydric alkanols (eg., Ethanol, propanol, Isopropanol, ethylene glycol, propylene glycol) - preferred in amounts of about 5 to 20 wt .-%, based on the entire rinse aid - to be incorporated.

Also very effective are hydrotropic substances such as Alkali salts of low molecular weight alkylbenzenesulfonic acids, Na Cumene sulfonate, Na xylene sulfonate or Na toluenesulfonate.

The amounts of the solubilizing and / or the hydrotropic substances may, depending on the cloud point of the Surfactant and the desired storage stability between 0 and 40 wt .-%, based on the total rinse aid, are.

In addition, to prevent limescale deposits on the dishes when using non-softened water in the rinse cycle additionally 0 to 40, preferably 10 to 35 wt .-%, based on the total rinse aid, complexing agents, such as citric acid, tartaric acid, glycolic acid and / or a commercial technical mixture of succinic acid, glutaric acid and adipic acid (Sokalan DCS ^(R) from BASF) can be used.

Also usable are complexing agents - if they are physiologically harmless - which have threshold-effective properties, such as. B. 2-phosphonobutane-1,2,4-tricarboxylic acid (Bayhibit AM ^(R) ). In this case, the Einsatzkonzentra tions may be less and 0 to 10, preferably 2 to 7 wt .-%, based on the total rinse aid amount.

Furthermore, in the usual way for use in clear Flushing agents of conventional colorants, fragrances and preservatives be added.

As starting material for the preparation of the polyglycol ethers of the general formula (I) may, 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) as well as alcohols said carbon number of other origin, for example Oxo alcohols, used singly or in admixture become.

For the preparation of the alkyl to be used according to the invention polyethylene glycol ethers of the general formula (I) are used suitably the fatty alcohols described above with ethylene oxide in the molar ratio of 1:20 to 1:40 and especially in molar ratios of about 1:25 to 1:35 and then etherified in the resulting reaction product existing hydroxy groups at least partially. The Reaction with ethylene oxide takes place under the known Alkoxylation conditions, preferably in the presence of suitable alkaline catalysts. The etherification of free hydroxyl groups is preferred among the known ones Conditions of Williamson ether synthesis with straight-chain and / or branched C₈ to C₁₄-alkyl halides carried out, wherein the use of appropriate alkyl chlorides is particularly suitable. It may be appropriate alkyl halide and alkali in an approximately stoichiometric ratio up to  to use about twice the stoichiometric excess, such that molar ratios of the ethoxylated alcohol to Alkyl halide in the range of about 1.0: 0.9 to 1.0: 2.0 are particularly suitable.

Finally, the invention relates to a further embodiment a process for producing low-foaming rinse aids for machine dishwashing in household and commerce, this process being characterized is that you surfactants or surfactant mixtures of the specified type produces and the resulting reaction product with water and / or the other mentioned excipients mixes.

Examples

The following examples summarize comparative examples State of the art and examples in the sense of the invention Acting together. The tested are tested On the one hand, with regard to their network assets a plastic surface and the other with respect to the Foaming tendency or the antifoaming effect. In detail the following applies to these tests:

Determination of network assets

The wetting power of the surfactant mixtures listed in the examples was determined by the following method:
In a plastic tub of 40 cm in length, 28 cm in width and 12 cm in height, 3 l of water with a water hardness of 16 ° dH and a temperature of 65 ° C filled. In this amount of water in each case 2.4 g of the surfactant mixtures specified in the examples are dissolved. Before a cooling of this liquid occurs, a plastic disk made of Makrolon with a diameter of 24 cm is completely immersed in this solution and left for about 30 seconds in this surfactant solution. Thereafter, the plate is pulled out and already visually assessed when pulling out. It is evaluated how quickly the water film, which is still adhering to the plastic plate when it is pulled out of cleaning solution, ruptures, resulting in dry spots being visible on the plate. If no dry spots are visible 10 seconds after removing the plate, ie if the plate surface is still 100% covered with a water film after this time, the rating is 100%. A rating of 60% means, on the other hand, that the plate surface after this time is only 60% covered by a water film. The higher this rating number for one of the surfactant mixtures given in the examples, the better is its wetting power.

Testing the antifoam effect

The foam-damping effect of the antifoams listed in the examples was tested according to the following test method:
In 500 ml of water with a water hardness of 16 ° dH 1 g of whole egg are whisked homogeneously and 1.5 g of dishwashing detergent "Topmat intensive" (brand name of the company Henkel) dissolved. This liquid is then poured into a double-walled measuring cylinder of 2000 ml and heated to 40 ° C. After reaching the test temperature, 0.25 g of the low-foaming surfactant mixture indicated in the examples are added to this amount of liquid. With the help of a laboratory hose pump, this solution is sucked with a glass tube from the bottom of the measuring cylinder. The return of the liquid in the measuring cylinder via a second tube whose lower end terminates at the level of the upper edge of the measuring cylinder. The liquid is circulated at a recirculation rate of 4 l / min and falls back into the graduated cylinder. This circulation of the liquid creates foam. After 1, 2, 3, 4, 5, 7 and 10 minutes of pumping the volumes indicated in the examples, which have formed from foam and liquid after these times, are read in each case.

Comparative Examples

Coconut alcohol is in each case a linear saturated fatty alcohol with the C-chain distribution of about 70% C₁₂ and 30% C₁₄ to understand.

Comparative Example 1

The surfactant mixture consists of
50% by weight of coconut alcohol-3EO-6PO
50% by weight of coconut alcohol 5EO-4PO
Rating net assets: 30%.

foaming minutes Volume (ml) 1 500 2 520 3 520 4 520 5 540 7 560 10 580

Comparative Example 2

The surfactant mixture consists of
50% by weight of coconut alcohol 5EO-4PO
50 wt .-% R (oCH₂CH₂) ₁₀-O-C₄H₉ (R = C _12/18 )
Rating Network Capacity: 50%

foaming 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- (OCH₂CH₂) ₁₀-o-C₄H₉ (R = C _12/18 )
20% Coconut Alcohol 23EO
20% R- (OCH₂CH₂) ₇-O-C₄H₉ (R = C _12/18 )
Rating Network Capacity: 90%

foaming 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- (OCH₂CH₂) ₁₀-O-C₄H₉ (R = C _12/18 )
25% coconut alcohol 23EO
Rating Network Capacity: 100%

foaming minutes Volume (ml) 1 740 2 800 3 920 4 1040 5 1300 7 1620 10 übergeschäumt | (more than 2000)

Comparative Example 5

The surfactant mixture consists of
70% coco-alcohol-3EO-6PO
30% cocoa-30EO
Rating Network Capacity: 80%

foaming minutes Volume (ml) 1 760 2 850 3 950 4 1130 5 1450 7 1860 10 übergeschäumt (more than 2000)

Examples according to the invention Example 1

The surfactant mixture consists of
57% coco-alcohol-3EO-6PO
23% R- (OCH₂CH₂) ₃₀-O-C₁₀H₂₁ (R = coconut alcohol)
20% Coconut Alcohol 23EO
Rating Network Capacity: 100%

foaming 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- (OCH₂CH₂) ₄₀-OC _12/14 H _25/29 (R = C _12/18 )
20% cocoa-30EO
Rating Network Capacity: 100%

foaming 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- (OCH₂CH₂) ₁₀-O-C₄H₉ (R = C _12/18 )
30% R (OCH₂CH₂) ₃₀-OC _12/14 H _25/29
20% cocoa-30EO
Rating Network Capacity: 100%

foaming minutes Volume (ml) 1 520 2 520 3 520 4 520 5 520 7 520 10 520

Claims (10)

1. Use of end-capped alkyl or alkenyl polyethylene glycol ethers of the general formula (I) R₁-O- (CH₂CH₂O) _n -R₂ (I) in the
R₁ is a straight-chain or branched alkyl and / or alkenyl radical having 8 to 18 C atoms,
R₂ is an alkyl radical having 8 to 14 C atoms and
n is a number from 20 to 40
mean, as a low-foaming and / or foam-damping surfactant component in aqueous rinsing and cleaning agents with in particular high wetting action over solid plastics. 2. Embodiment according to claim 1, characterized in that compounds of the general formula (I) are used, in which R₂ is an alkyl radical having 8 to 10, in particular 10 C-atoms, and n is a number from 25 to 35. 3. Surfactant mixtures for use in dishwashing detergents and cleaning agents, in particular rinse aids, with high wetting action compared to solid plastics, but with reduced foaming, containing

• (A) alkyl or alkenyl polyethylene glycol 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 each R₁ has the meaning given for the formula (I).
• (B-1) Compounds of General Formula (II) in the
  R₃ is a methyl or ethyl radical and
  a is a number from 2 to 6 and
  b is a number from 3 to 7
  mean,
• (B-2) Compounds of general formula (III) R₁-O- (CH₂CH₂O) _c -R₄ (III) in the
  R₄ is an alkyl radical having 4 to 8 carbon atoms and
  c is a number from 7 to 12
  mean,
• (B-3) Compounds of the general formula (IV) R₁-O- (CH₂CH₂O) _d -H (IV) in the
  d is a number from 20 to 50 and preferably from 25 to 35.

4. surfactant mixtures according to claim 3, characterized that they mixtures of alkyl or Alkenylpolyglykolethern the general formulas (I) and (II) in the mixing ratio of 50: 50 to 20: 80 parts by weight of (I): (II).   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)
From 10 to 40% by weight, preferably from 15 to 30% by weight, of compounds of the general formula (IV)
From 20 to 80% by weight, preferably from 45 to 65% by weight, of compounds of the general formulas (II) and / or (III). 6. Low-foaming rinsing and / or cleaning agents, in particular Rinse aid for machine dishwashing in household and commercials with improved network characteristics Plastics based on a preferably aqueous solution not ionic surfactants from the class of alkyl and / or alkenyl Polyethylene glycol ethers, if desired containing solubilizers, hydrotropic substances, means of prevention the limescale, fragrances and / or dyes and optionally further auxiliaries, characterized in that they Surfactant mixtures according to claims 3 to 6 in amounts of about 5 to 80 wt .-%, in particular in amounts of about 15 to 50 wt .-% included. 7. Low-foaming flushing 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, glutaric and adipic acid in amounts of 0 to 40 wt .-%, preferably from 10 to 35 wt .-% and / or threshold-active complexing agents, such as 2-phosphonobutane 1,2,4-tricarboxylic acid, in amounts of 0 to 10 wt .-%, preferably from 2 to 7 wt .-%, contained - wt .-% in each case on the entire rinse aid.   8. Low-foaming rinsing and / or cleaning agents according to claims 6 and 7, characterized in that they are cumene sulfonate in amounts of 5 to 20 wt .-%, based on the total Rinse aid, included. 9. Low-foam rinsing and / or cleaning agents according to claims 6 and 7, characterized in that they are low Alcohols such as ethanol and / or isopropanol in amounts of 5 to 20 wt .-%, based on the total rinse aid included. 10. Process for the preparation of low-foaming rinse aids for machine dishwashing in household and commercial, characterized in that alkanols or alkenols of Formula R₁-OH, in which R₁ is a straight-chain or branched Alkyl or alkenyl radical having 8 to 18 carbon atoms, 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 ethoxylated, then the free hydroxyl groups with straight-chain or branched C₈ to C₁₄-alkyl halides, preferably alkyl chlorides, etherified and thereby in particular with molar ratios of the ethoxylated alcohol to the alkyl halide in the range of 1.0: 0.9 to 1.0: 2.0 works and the resulting reaction product with water and / or the other mentioned excipients mixes.