DE4401235A1 - Rinse aid for the automatic cleaning of dishes - Google Patents

Abstract

The object of the invention is the use of C6-C10-n-alkyl sulphates in rinsing agents. Preference is given to rinsing agents containing: a) 0.5 to 20 wt. %, preferably 2 to 10 wt. % of a C6-C10-n-alkyl sulphate or its alkaline or ammonium salt, especially Na salt; b) 0.5 to 30 wt. %, preferably 2 to 20 wt. %, of a fatty alcohol ether of formula (I) in which R<1> is a linear or branched alkyl and/or alkenyl radical with 8 to 18 C atoms, m is a number from 0 to 6 and n is a number from 1 to 6, and/or 0.5 to 30 wt. %, preferably 2 to 20 wt. %, of a fatty alcohol ether of formula (II) in which R<2> is a linear or branched alkyl or alkenyl radical with 8 to 14 C atoms, R<3> is a methyl, ethyl, a linear or branched alkyl radical with 3 or 4 C atoms or a benzyl radical and x is a number from 5 to 15, and c) 0.5 to 30 wt. %, preferably 1 to 20 wt. %, related to the entire agent, of an organic di or tricarboxylic acid with 2 to 6 C atoms, preferably citric acid.

Description

Field of the Invention

The invention relates to the use of C₆-C₁₀-n-alkyl sulfates in clear detergents for the automatic cleaning of dishes.

State of the art

Commercial rinse aids are mixtures of low-foaming fat alcohol polyethylene / polypropylene glycol ethers, solubilizers (e.g. Cumene sulfonate), organic acids (e.g. citric acid) and solvents (e.g. ethanol). The purpose of these agents is to: To influence the interfacial tension of the water so that it is possible in one Lich thin, coherent film can run off the dishes, so that during the subsequent drying process, no water drops, streaks or Films lag behind. An overview of the composition of rinse aid Learning and methods for checking performance can be found by W. Schirmer et al. in tens. Surf. Det. 28, 313 (1991).

When using modern phosphate-free and low-alkaline cleaners for automatic dishwashing, it can also form lime or silicate deposits on the wash ware and inside the machine, because the calcium binding capacity of these cleaners is lower than that of classic products containing phosphates. Disturbing lime or silicate coverings occur especially when the dishwashing water from the dishwasher is not or not sufficiently softened and a water hardness of 4 ° d is exceeded. In such cases, lime or silicate coverings can be used Avoid effectively if an organic acid, e.g. B.  Citric acid is dosed into the rinse aid. Standard rinse aid therefore contain considerable amounts of organic acids, mostly citrus nenoic acid.

From EP-B1 0 197 434 (Henkel) rinse aids are known which are used as surfactants Mixed ether included. In the dishwasher, a large number of un different materials (glass, metal, silver, plastic, porcelain) cleaned. This variety of materials must be as good as possible in the rinse aid process be wetted. Rinse aid formulations made up as a surfactant component finally contain mixed ethers, do not meet these requirements or only to a small extent, so that the rinse aid or drying effect in particular especially with plastic surfaces, e.g. B. polycarbonate, not satisfied is posed.

The unpublished German patent application P 43 23 252.3 be writes rinse aid, the surfactant mixtures of mixed ethers and fat contain alcohol ethoxylates or fatty alcohol propoxylates. Such clear dishwashers show a positive behavior towards plastic surfaces; at these formulations, however, can generally not be based on a solution medium such as B. cumene sulfonate can be dispensed with. Such solution brokers do not develop any surfactants themselves. H. wetting effect, they perform so no contribution to the rinse aid effect. Other disadvantages of this solution intermediaries are that they are manufactured on a petrochemical basis and are only slowly biodegradable.

The object of the present invention is therefore to provide powerful rinse aid to provide formulations that differ from those customary in the market Rinse aids in principle without the usual solubilizers such as cumene sulfonate get along.

It has now been found that unbranched C₆-C₁₀-n-alkyl sulfates solubilizing effect of typical solubilizers such as Achieve and sometimes even surpass cumene sulfonate at the same time surfactant, d. H. Develop wetting effects that lead to Add rinse aid. Compared to the typical solubilizer Cumene sulfonate with C₆-C₁₀-n-alkyl sulfonates at lower  Same phase stability (solubilizing effect) as well as slightly to significantly better rinse aid effects (wetting effect) achieved. In addition, C₆-C₁₀-n-alkyl sulfates are generally fat chemical origin and therefore biodegradable.

The invention therefore relates to the use of C₆-C₁₀-n-alkyl sul faten and their alkali or ammonium salts, especially sodium salts, in Rinse aid for machine washing dishes.

N-Octyl sulfate and its alkali metal or ammonium are particularly preferred salt, especially Na-n-octyl sulfate. Preferably the C₆-C₁₀-n- Alkyl sulfates as co-surfactants in acidic rinse aid formulations based nonionic surfactants, especially fatty alcohol ethers, are used. In Such formulations occur at the same time wetting and dissolving averaging effect particularly well.

Another subject of the invention is therefore rinse aid

• a) 0.5 to 20 wt .-%, preferably 2 to 10 wt .-%, of a C₆-C₁₀-n- Alkyl sulfate or its alkali or ammonium salt, especially Na salt,
• b) 0.5 to 30% by weight, preferably 2 to 20% by weight, of a fatty alcohol ether of the formula I. in which R¹ is a linear or branched alkyl and / or alkenyl radical having 8 to 18 carbon atoms, m is a number from 0 to 6 and n is a number from 1 to 6,
  and / or 0.5 to 30 wt .-%, preferably 2 to 20 wt .-%, of a fatty alcohol ether of the formula IIR²-O- (CH₂-CH₂O) _x R³ (II), in which R² for a linear or branched Alkyl or alkenyl radical with 8 to 14 carbon atoms, R³ for a methyl, ethyl, a linear or branched alkyl radical with 3 or 4 carbon atoms or a benzyl radical and x stands for numbers from 5 to 15, and
• c) 0.5 to 30 wt .-%, preferably 1 to 20 wt .-%, each based on the entire agent, an organic di- or tricarboxylic acid 2 to 6 carbon atoms, preferably citric acid.

The C₆-C₁₀-n-alkyl sulfates are commercially available products, the i.a. by sulfating C₆-C₁₀ alcohols, e.g. B. Capron, Capryl or capric alcohol. The Na-n- Octyl sulfate, commercially available under the name Texapon 842 (from Henkel) is available.

The fatty alcohol ethers of the formula I are not known ionic surfactants, which can be obtained by adding propylene oxide and then receives ethylene oxide or only ethylene oxide on fatty alcohols. Examples are polyglycol ethers of the formula (I) in which R 1 is an alkyl remainder with 8 to 18 carbon atoms, m for numbers from 0 to 6 and n for Numbers from 1 to 6 stands. The indices n and m represent a be correct commercial product represents mean values, since in practice there is always a ver division of addition products of different degrees of alkoxylation is present.

Examples of fatty alcohol ethers of the formula I are e.g. B.
Dehydol LS-2: C _12/14 coconut fatty alcohol 2EO adduct;
Dehydol LS-4: C _12/14 coconut fatty alcohol 4EO adduct;
Dehydol LS-5: C _12/14 coconut fatty alcohol 5EO adduct;
Dehypon LS-54: C _12/14 coconut fatty alcohol 5EO-4PO adduct;
Dehypon LS-45: C _12/14 coconut fatty alcohol 4EO-5PO adduct;
all fatty alcohol ethers mentioned are sales products from Henkel (EO ethylene oxide, PO propylene oxide).

The fatty alcohol ethers of the formula (II) are known end-capped fatty alcohol polyglycol ethers which can be obtained by the relevant methods of preparative organic chemistry. Fatty alcohol polyglycol ethers are preferably reacted in the presence of bases with alkyl halides, in particular butyl or benzyl chloride. Typical examples are fatty alcohol ethers of the formula (II) in which R² is an industrial C _12/14 cocoalkyl radical, x is 5 to 10 and R³ is a butyl group (Dehypon LT 54 or LS-104, from Henkel) . The use of mixed ethers containing butyl or benzyl groups is particularly preferred for technical reasons.

The rinse aid according to the invention can be the C₆-C₁₀-n-alkyl sulfates and the fatty alcohol ethers of the formula I or II in a weight ratio of 10:90 to 80:20, preferably 30:70 to 70:30 and in particular 30:70 to 40: 60 included.

As organic di- or tricarboxylic acids with 2 to 6 carbon atoms come z. B. Malic acid, tartaric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, Adipic acid, but especially citric acid.

In terms of performance, the rinse aids according to the invention are commercially available Formulations regarding the desired minimal foaming, the drying effect, the rinse aid effect and the phase stability native and sometimes even superior, without the use of additional Solution brokers to be instructed. Fall within the scope of the invention but also rinse aid formulations that also contain small amounts (up to approx. 3 wt .-%, based on the total agent) of conventional solubilizers contain.

In the simplest case, the rinse aid according to the invention is excluded the C₆-C₁₀-n-alkyl sulfate is only a fatty alcohol ether of the formula I with m = 0, i.e. H. an ethoxylated C₈-C₁₈ alcohol, e.g. B. Dehydol LS-2, LS-4 or LS-5 included. Alternatively, only a fatty alcohol ether can be used of formula I with m ≠ 0, d. H. a propoxylated and then ethoxy Liert C₈-C₁₈ alcohol, e.g. B. Dehypon LS-54 or Dehypon LS-45 included his. Any conceivable mixture of one or more fatty alcohols  ethers of the formula I with m = 0 and one or more fatty alcohol ethers Formula I with m ≠ 0 is conceivable.

In addition, any of the possible individual substances or mixtures can gene also a fatty alcohol ether of formula II, for. B. Dehypon LT 54 or Dehypon LS-104. The fatty alcohol ethers of the formula II can nen - as a single substance or in a mixture of different fatty alcohol ethers of the formula II - also as the sole fatty alcohol ether component without simultaneous presence of a fatty alcohol ether of formula I used become.

Optionally contained in the rinse aid according to the invention Substances can be nonionic surfactants of the C der-C₁₈ alkyl glucoside type and / or the N-C₆-C₁₈ acylglucamides and dyes and fragrances become.

Examples

Compositions 1 to 13 were made by simply mixing the com components manufactured. Compositions 1 and 2 are rinse aid of the State of the art, compositions 3 to 13 are according to the invention (Figures in% by weight).  

Performance test of the rinse aid formulations I. Testing the foam behavior of the rinse aid formulations

The foam development of the rinse aid was with the help of a revolution pressure measuring device determined. The rinse aid (3 ml) was Hand rinse cycle at 50 ° C.

Here mean:
0 points = no foam development
1 point = weak foaming
2 points = medium foam development (still acceptable)
3 points = strong foaming

II. Drying

The door of the Ge dishwasher fully open. After 5 minutes the Drying by counting the remaining drops on those listed below Dishware determined.

Rating:
0 points = more than 5 drops
1 point = 5 drops
2 points = 4 drops
3 points = 3 drops
4 points = 2 drops
5 points = 1 drop
6 points = 0 drops (optimal drying)

III. Rinse aid effect

After assessing the drying, the dishes were outside the Dishwasher turned off for 30 minutes to cool and then un The lighting in a black box is visually matched. Appraisal the remaining ones on the dishes and cutlery were divided dried residual drops, streaks, deposits, cloudy films etc.  

Rating:
0 points = poor rinse aid effect
8 points = optimal rinse aid effect
For the performance tests II. And III. The tests were carried out in the Bauknecht GSf 1162 dishwasher with softened water. The 65 ° C normal program was selected for this. 30 ml of Somat® cleaner (Henkel) were dosed in the cleaning cycle. The amount of rinse aid - the rinse aid composition shown in Table 1 - was 3 ml, exceptions: Examples 5, 7 and 8 each only 2 ml, and was dosed by hand at 50 ° C in the rinse aid. The salt load in the water was between 600 and 700 mg / l. 3 rinse cycles were carried out for each rinse aid formulation.

The following were used to assess the drying and the rinse aid effect Dishes used

• - "Neckar-Becher" glasses (Schott-Zwiesel), 6 pieces
• - Stainless steel knife "Brasilia" (from WMF), 3 pieces
• - White porcelain dinner plates (from Arzberg), 3 pieces
• - red plastic plate "Valon dinner plate" (Fa. Haßmann), 3 pieces

It was found that the n-octyl sulfate-containing preparations 3 to 13 ge compared to the preparations containing solubilizers with regard to Drying of the crockery parts, the foaming behavior and the rinse aid effect have equivalent to slightly better performances.

Claims (3)

1. Use of C₆-C₁₀-n-alkyl sulfates and their alkali or ammo nium salts, especially sodium salts, in rinse aid for the machine After washing dishes. 2. Use according to claim 1, characterized in that the C₆-C₁₀-n-alkyl sulfate is n-octyl sulfate. 3. Containing rinse aid

• a) 0.5 to 20% by weight, preferably 2 to 10% by weight, of a C₆-C₁₀-n-alkyl sulfate or its alkali or ammonium salt, in particular sodium salt,
• b) 0.5 to 30% by weight, preferably 2 to 20% by weight, of a fatty alcohol ether of the formula I. in which R¹ is a linear or branched alkyl and / or alkenyl radical with 8 to 18 carbon atoms, in for numbers from 0 to 6 and n for numbers from 1 to 6,
  and / or 0.5 to 30% by weight, preferably 2 to 20% by weight, of a fatty alcohol ether of the formula IIR²-O- (CH₂CH₂O) _x R³ (II), in which R² is a linear or branched alkyl or Alkenyl radical with 8 to 14 carbon atoms, R³ for a methyl, ethyl, a linear or branched alkyl radical with 3 or 4 carbon atoms or a benzyl radical and x stands for numbers from 5 to 15, and
• c) 0.5 to 30% by weight, preferably 1 to 20% by weight, based in each case on the total agent, of an organic di- or tricarboxylic acid having 2 to 6 carbon atoms, preferably citric acid.