WO1995019422A1 - Machine care sticks - Google Patents

Abstract

Sticks for the care of unloaded dishwashers consist of a solidified mixture of wax, nitrogenated surfactants and if required other non-ionic surfactants, water-soluble polyvalent alcohol, water-soluble organic carboxylic acids with one or more bases, if required substituted by hydroxyl groups and having 2 to 6 carbon atoms in the molecule, and if required dyes and/or perfumes, small amounts of solubilisers therefor and corrosion inhibitors. The nitrogenated non-ionic surfactants are fatty acid-N(R)-polyhydroxyalkylamides, in particular fatty acid-N(R)-glucamides having the general formula R1-CH2-CO-N(R)-CH2(CHOH)4-CH2OH, in which R = H, -CH3, -C2H5, -C3H7, -C4H9 and R1 = CnH2n+1, and n = about 8 to 16. Also disclosed is a process for producing such sticks and their use.

Description

 "Machine care ft"

In the area of the door seals, hose connections and low-flow zones of dishwashers, that is to say where the surfaces of the interior of the dishwasher are not exposed to the direct and intensive operating pressure of the cleaning liquor, deposits of dirt which essentially occur consists of finely divided, fatty food residues.

Occasional, unavoidable, technical faults in the ion exchange system of dishwashers, which serve to soften the water used, or due to continuous underdosing of the detergents by the users, deposits gradually develop on the inner surfaces of the machines a mixture of lime from hard water and detergent residues - so-called "tarnish colors", as the rainbow-colored discolorations of stainless steel parts of dishwashers are called.

These dirt deposits offer an undesirable breeding ground for putrefaction processes which are noticeable through an unpleasant odor, especially when the dishwashers are opened after a long period of non-use. In addition, however, the hose and sealing materials, especially on the doors, are also damaged by long-term exposure to these dirt deposits.

The commercially available powdery alkaline or acidic dishwashing, cleaning or rinsing agents are not or only insufficiently suitable for cleaning the so-called "problem areas" of the dishwashers which are at risk of contamination, since they are metered into and dissolved in the cleaning or rinsing cycle of the dishwashers can, but either not touch the soiled areas or touch them for a short time. For this reason, for a long time it was only necessary to manually clean such zones. The detergents used for cleaning dishes are unsuitable for such cleaning because they attack the skin too strongly. Commercial cleaning agents for hard surfaces are also available for these not suitable for special applications, since they generally contain highly foaming surfactants, the residues of which in dishwashers can lead to various types of faults.

Machine cleaners for household dishwashing machines are already offered as such on the market, in liquid form. The bottle required for this and the associated bottle cap mean, from an ecological point of view, a relatively high expenditure on packaging. EP 033 111 describes the use of a liquid, aqueous or aqueous-alcoholic, acidic agent containing water-soluble organic mono- or polybasic carboxylic acids, optionally substituted by hydroxyl groups, with 2 to 6 carbon atoms in the molecule, water-soluble polyhydric alcohols, low-foaming Non-ionic surfactants and other additives from the group of fragrances, dyes, solubilizers and / or corrosion inhibitors for cleaning and maintaining the inner surfaces of household dishwashers are known, the agent being used manually in concentrated form on an absorbent substrate or in amounts of 5 to 40 g / 1 water volume of the machine in the cleaning aisle of the unloaded machine and let the cleaning run as usual. It was therefore an object of the invention to find an ecologically more economical, yet user-friendly form of offer.

The unpublished DE 42 33 698 describes that the components of this liquid machine cleaner can be formulated in a wax base instead of in water. As a result, lower amounts of use are possible and therefore a more economical consumption of ingredients compared to the liquid machine maintenance. In addition, the number of ingredients could be reduced to the active substances, since the use of solubilizers in addition to the wax is no longer necessary. In contrast to the liquid products used in bottles, the machine care pen can, depending on the degree of soiling of the machine and the capacity of the dishwasher, also be divided into pieces of any length and thereby portioned, so that the use of chemicals can be further reduced as a result. The invention now relates to pens for the care of unloaded dishwashers, which are characterized in that they have a solidified mixture of wax, nonionic surfactants, water-soluble polyhydric alcohols, water-soluble organic mono- or polybasic carboxylic acids, optionally substituted by hydroxyl groups, with 2 up to 6 carbon atoms in the molecule and, if appropriate, colorants and / or fragrances, small amounts of solubilizers for these and corrosion inhibitors and the nonionic surfactants completely or to a substantial extent of at least 50% by weight from nitrogenous compounds there exist.

Wax-like compounds or wax mixtures that form the matrix of the machine care stick must melt completely in the range between 40 ° C. to 60 ° C. and preferably in the range between 45 ° C. to 55 ° C. so that the cleaning and care components are released in the dishwasher ¬ can be set. Low-melting polyethylene waxes as well as macrocrystalline n-paraffin are therefore preferred as wax-like compounds. Higher melting waxes such as the microcrystalline waxes of petrochemical origin or natural waxes such as carnauba wax, candellila wax, beeswax, montan waxes can only be used in combination with low-melting polyethylene waxes or low-melting macrocrystalline n-paraffins or petroleum jelly. Polyethylene glycols with an average molecular weight (MW) of about 1,000 to 12,000, preferably 3,000 to 6,000 and a melting (softening, dripping) point of about 40 to 60, preferably about 45, are preferably used as waxes. 55 ° C used. Their amount in the pen is about 45 to 95, preferably about 50 to 90% by weight. Although this appears to be a great deal in comparison with the water content of the known liquid care products, comparatively little packaging effort is required for the pen. The liquid cleaning and care products are offered in disposable polyethylene bottles. This use of packaging material is not necessary for the machine care pen. In addition, the wax matrix and the polyvalent water-soluble alcohols dissolved in the care stick serve as care components with which the rubber parts of the dishwasher are coated can be so that they remain supple and their life is extended.

Nonionic surfactants which are preferably used are those which are readily biodegradable and / or which are based on renewable raw materials.

According to the invention, biodegradable and rapidly degradable nitrogen-containing nonionic surfactants are used, namely fatty acid-N (R) -polyhydroxyalkylamides, in particular fatty acid-N (R) -glucamides of the general formula Rι-CH2-CO-N (R) -CH2 (CH0H ) - ₄ CH2-0H with R = H, -CH3, ^ 5, -C3H7, -C4H9 and Ri = C _n H2n + l. where n = about 8 to 16. These compounds are also referred to below as "fatty acid amides".

The fatty acid amides to be used according to the invention are preferably derived from reducing sugars having 5 or 6 carbon atoms, in particular from glucose. The preferred fatty acid N-alkylpolyhydroxyalkylamides are therefore fatty acid N-alkylglucamides, as represented by the following formula:

R ² OH OH OH

IIIIR ¹ CO-N-CH ₂ -CH-CH-CH-CH-CH2θH.

I OH

Suitable raw materials for the preparation of the agents used according to the invention are fatty acid N-alkylpolyhydroxyalkylamides of the formula Rι-C0- (R2) (Z), in which R * C0 for an acyl radical having 6 to 12 carbon atoms, R ² for a methyl group and (Z) stands for reduced glucose residue. Accordingly, fatty acid N-methylglucamides are particularly preferred, which are obtained by reductive amination of glucose with methylamine and subsequent acylation with a C6-Ci2 fatty acid or a corresponding derivative. When choosing the fatty acid comes one in particular Cg-Cio fraction in question, which is obtained, for example, as a preliminary step in the distillation of technical coconut fatty acid.

These fatty acid N-alkyl polyhydroxyalkylamides are known substances which can usually be obtained by reductive amination of a reducing sugar with ammonia, an alkylamine or an alkanolamine and subsequent acylation with a fatty acid, a fatty acid alkyl ester or a fatty acid chloride. Overviews can be found u. a. in Tens.Surf.Det. 25., 8 (1988) and in SÖFW-Journal, 119. (1993) pages 794-808. With regard to the processes for their production, reference is also made to US Pat. Nos. 1,985,424, 2,206,962 and 2,703,798 , the German Auslegeschrift DE-AS 12 61 861 and the international patent application WO 92/06984 referenced.

The use of the fatty acid amides mentioned is also the subject of a large number of publications. Their use as a thickener is known, for example, from European patent application EP-AI 0 285 768 (Hüls). French patent application FR-A 1 580 491 (Henkel) describes aqueous detergent mixtures based on sulfates and / or sulfonates, nonionic surfactants and, if appropriate, soaps, which contain fatty acid N-alkylgluca ide as foam regulators.

Mixtures of fatty acid N-alkylglucamides with anionic surfactants, surfactants with sulfate and / or sulfonate structure, ether carboxylic acids, ether sulfates, methyl ester sulfonates and other nonionic surfactants are the subject of international patent applications WO 92/6153; 6156; 6157; 6158; 6159 and 6160 (Procter & Gamble), the use of these substances in a wide variety of washing, rinsing and cleaning agents is described in international patent applications WO 92/6152; 6154; 6155; 6161; 6162; 6164; 6170; 6171 and 6172 (Procter & Gamble). However, these documents do not contain any reference to the advantageous use of these substances in compositions for use in accordance with the invention.

In addition, other nonionic surfactants can also be added to the care stick composition. This includes in particular te of about 2 to 15, preferably about 2 to 10, mol of ethylene oxide (EO) of fatty alcohols with about 8 to 22, preferably about 12 to 18, carbon atoms in the alkyl radical and modified fatty alcohol ethoxylates, the end group of which has a short-chain alkyl radical (for example butyl ) is closed. Suitable alkyl polyglycol ethers are, for example, the dehydol () types from Henkel, such as dehydol ( ^R ) LS 2, dehydol ( ^R ) LS 4, dehydol ( ^R ) LS 5 and dehydrol ( ^R ) LT 2, dehydol ( ^R ) LT 3 and Dehydol ( ^R ) LT 4. The dehydol products of the LS series are EO adducts with fatty alcohols with a chain length in the range of approximately C12-C14 and the LT series are those in the chain length range of approximately C ^ -Ciβ- Modified alkyl polyglycol ethers are, for example, alkyl ethoxylates which are end group-capped with a butyl group, such as, for example, Dehypon ( ^R ) LS 104, Dehypon ( ^R ) LT 104 and Dehypon ( ^R ) LT 054 from Henkel. Suitable alkyl polyglycol ethers based on oxo alcohol are lutensol ( ^R ) A 03, lutensol ( ^R ) A 04 from BASF, and also alkyl ethylene oxide / propylene oxide adducts, in particular adducts of about 1 to 10 mol of ethylene oxide and about 1 to 8 mol of propylene oxide with higher molecular weight fatty alcohols with about 8 to 20, preferably about 12 to 18 carbon atoms in the molecule or mixtures thereof, and also on synthetic alcohols, for example produced by oxosynthesis, of the possible chain length C13-C15. In addition, nonionic surfactants can also be alkyl polyglycosides with alkyl chains in the range of approximately Cβ-C12 and a degree of polymerization of approximately 1 <x 3, but preferably alkyl polyglycosides with alkyl chains in the range of approximately Cg-C10 and a degree of polymerization of approximately 1 <x < 3 are used. Their amount is 0 to about 3, preferably about 0.01 to 2.5% by weight, based on the fatty acid amide. ( ^C 8 " ^C 12) alkyl polyglycolsides, such as, for example, APG ( ^R ) 225 (Henkel), also known as Plantaren ( ^R ) 225, Lutensol ( ^R ) GD 70 (BASF) are preferably used. From a purely technical point of view Instead of the easily and quickly biodegradable fatty alcohol polyglycol ethers or alkylpolyglycosides, the difficult or only partially biodegradable EO-PO block polymers or alkylphenol polyglycol ethers can be used, such as ethylene oxide adducts with higher molecular weight propylene glycols with a molecular weight of 900 to 4000, e.g. Pluronic ( ^R ) -Types from BASF such as Plusonic ( ^R ) = PE 3100, Plusonic PE 4300. Suitable alkylphenyl polyglycol ethers are, for example, Lutensol ( ^R ) AP 6, Lutensol ( ^R ) AP 7 from BASF. The total amount of nonionic surfactants is about 0.5 to 15, preferably about 1 to 10,% by weight, the ratio of fatty acid amides to other nonionic surfactants being about 2: 0 to 1: 1.

Ethylene glycol, propylene glycol and preferably glycerin are used as water-soluble polyhydric alcohols. Their amounts are about 0.01 to 10, preferably about 0.05 to 7 percent by weight.

As water-soluble organic mono- or polybasic, optionally substituted by hydroxy groups, carboxylic acids with 2 to 6 carbon atoms in the molecule, preference can be given to those polyvalent acids which, based on the first dissociation stage, have a K _s value of> 10 ~ 6. These are, for example, adipic acid, succinic acid, tartaric acid, malic acid, glutaric acid, oxalic acid, malonic acid, succinic acid and preferably citric acid. Mixtures of such acids can also be used. Their amount is about 5 to 50, preferably about 10 to 40% by weight.

In addition to dyes and fragrances, the agents may also contain small amounts of about 0.1 to 2.5% by weight of solubilizers for the fragrances, for example dipropylene glycol, and corrosion inhibitors, for example one under the name Rodine 58 ( ^R ) Gerhard Collardin GmbH, Cologne, known condensation product made from aldehydes and amines, as well as long- and short-chain fatty acids, produced in an acid medium.

The care products according to the invention dissolve and remove both the greasy food residues as well as lime and cleaning agent residues in the dishwashers. The tarnish also disappears when rubbed off. As a result of the content of polyvalent water-soluble alcohols, the stick is prevented from drying out prematurely. This not only keeps rubber and plastic seals or connections soft and elastic in the machine area, but also stubborn dirt is softened and easy to wipe off due to the delay in re-drying. To produce the care product according to the invention, the organic carboxylic acid is stirred into the liquefied wax which has been heated to its melting point, then the nonionic surfactant (s), the water-soluble polyhydric alcohols and, if appropriate, the colorants and / or fragrances , Solution mediator for this and a corrosion inhibitor stirred. The still hot mass is then poured into sleeves lined with a protective film, for example with a capacity of about 100 g, and allowed to solidify. The complete wrapping with the protective film takes place automatically. The pins thus encased can then be removed from the sleeves.

In a further preferred production process, the wax matrix is melted and the organic carboxylic acid and the other formulation components such as nonionic surfactant (s), water-soluble polyhydric alcohols, optionally colorants and / or fragrances, a solubilizer therefor, and Corrosion inhibitors, mechanically dispersed therein. The liquid care stick mass is then poured into a release agent, e.g. Poured water, painted metal or plastic mold. After cooling, the machine care stick is released from the mold and placed in a protective film, e.g. packed in a polyethylene, polypropylene or in a hot water soluble polyvinyl alcohol film.

A warm water-soluble polyvinyl alcohol film has the advantage that the packaged machine care stick can be placed directly in the machine, so that the consumer does not have to have any contact with the product.

It is advisable to wrap the finished care pens before packaging in film by immersing them in n-paraffin with a melting point of about 30 ° C to 60 ° C, preferably about 45 ° C to 50 ° C. This not only makes contact with the stylus more pleasant, but also reduces the amount of foam that might otherwise occur.

During use, part of the protective film can first be removed from the pen while it is held in hand with the rest and thus rubbing in the rubber parts of the dishwasher. Then you remove the Protective film completely, lets the remaining pin slide into the cutlery box and the usual cleaning program runs with the otherwise unloaded machine. A further increase in gloss in the interior of the machine can be achieved if the care process taking place in the cleaning cycle is followed by a rinse cycle equipped with a rinse aid.

B e i s p e l e

The following non-coated and paraffin-coated care pens were produced in the manner described:

Table 1 without paraffin coating

Example 1% by weight

Cβ-Cio-fatty acid-N-methylglucamide 3.0 Ci2-Ciδ-fatty alcohol + 3.0 EO 1.5

Citric acid anhydrous 34.0 fragrance 0.25

Polyethylene glycol MG = 1500 58.95 Glycerin 1.0

Water from raw materials 1.3

Table 2 with paraffin coating (2-3 g n-paraffin with F: 46 ° C - 48 ° C per stick)

Example 2% by weight

C6-Ci2 fatty acid N-methylglucamide 3.0

Citric acid anhydrous 35.0

Perfume 0.25

Polyethylene glycol MG = 1500 59.45

Glycerin 1.0

Water from raw materials 1.3

E0 = ethylene oxide The practical application and effectiveness of the pens according to the invention for cleaning the inside of dishwashers was determined on the basis of the lime dissolving (I) and cleaning ability (II), cleaning performance (III) and drying (IV). Another important criterion is the foam behavior (V) of the machine care worker in the dishwasher.

I. Descaling power

For this purpose, the dishwasher fully loaded with dishes was operated in a 65 ° C normal program with hard water (16 ° C). In addition, 120 g of 50% sodium hydroxide solution were added to the cleaning cycle. For the production of stubborn, accumulated limescale deposits on dishes, cutlery and in the interior of the dishwasher, five washing cycles were carried out.

Removal of limescale

The limescale deposits produced in the manner described above could be removed easily with the machine care formulations 1 and 2 according to the invention. For this purpose, 100 g of machine care pen were placed in the cleaning aisle of a standard Miele G 590 dishwasher; the maximum rinse temperature was 55 ° C ± 3 ° C. The rinsing liquor in the cleaning cycle had a water volume of 5 ± 0.5 1.

Table 3

Quantity balance for heavy limescale deposits

liquid pen

Quantity used per care cycle 250 ml = 250 g 100 g packaging material1 PE bottle with PE film closure

= 26 g - 2 g

II. Cleaning ability

To determine the cleaning ability of the manually applied agents according to the invention of rubber and plastic parts of a tableware The following test application was used in the dishwasher. 2 g of an artificial soiling consisting of a mixture of carbon black, machine oil, triglycerides of saturated fatty acids and low-boiling aliphatic hydrocarbons were applied uniformly to a plastic test plate of 26 x 28 cm with the aid of a surface coater. The care stick according to Example 2 was moved mechanically on the test surface. After 6 strokes, the cleaned test area was kept under running water and the loose dirt was removed. The cleaning effect, i.e. the whiteness of the plastic surface cleaned in this way, was measured with a photoelectric color measuring device LF 90 (Dr. B. Lange). The original, clean, white plastic surface served as the white standard. During the measurement, this clean surface was set to 100 percent and the soiled area to 0 percent. The stated values of the cleaned plastic surfaces are to be regarded as percent cleaning capacity (% RV). They are averages from a 4-fold determination. A% RV of 21 was obtained with tap water.

example

RV 42

III. Cleaning performance

The result of the machine application of the agent according to the invention for cleaning the interior of the dishwashers was, inter alia, also determined in the form of cleaning performance. For this purpose, with a water content of the machine of 10.0 i 0.5 1 per 250 ml, an agent according to Example 1 was added to the cleaning cycle of a standard Miele G 590 dishwasher; the maximum rinse temperature was 55 ° C ± 3 ° C. On stainless steel surfaces of the interior of the dishwasher of 3 Miele G 590 machines there was 30 g of soiling, consisting of 100 g margarine

50 g raw egg (white and yellow)

50 g of defrosted frozen spinach 100 g drinking milk; 1.5% fat content 100 g drinking oat flakes 200 g mashed potatoes 400 g gravy, brown applied with a brush in the form of a strip and left to dry for 20 hours at room temperature. Then a pen according to Example 1 was placed in the cleaning cycle of the dishwasher and started as usual; the result was then assessed by three test subjects. The original new stainless steel inner surface was rated 10 (absolutely clean) and the stainless steel surfaces obtained after the soiling had dried on with 0. The cleaning grade 5.5 was achieved with pure water treatment.

example

Cleaning performance 7.0

IV. Drying effect

The drying effect is the application-technical criterion with which the effectiveness of the machine operator is assessed. After the rinse cycle has ended, it is checked whether the interior of the dishwasher is dry. For this purpose, the door of the dishwasher is fully opened 15 minutes after the end of the washing program. After 5 minutes, the drying is determined by counting the remaining drops in the machine ceiling and on the upper crockery basket and the cutlery basket. The evaluation is graded and comprises seven grades: 0 points - the interior of the machine is still completely wet, 6 points - stand for an optimally dry interior of the dishwasher.

Table 4 shows the drying values of recipes 1 and 2. Drying is particularly good if fatty acid amide / fatty alcohol ethoxylate mixtures are used and if additional rinse aid is added in the rinse cycle. Machine: Bauknecht GSF 1162

Program: 65 ° C normal program

Water: soft 3 ° dH

Machine care dosage: 100 g

Rinse aid dosage: 3 ml

Rinse aid composition: Somat Citrus rinse aid (Henkel KGaA)

Rating:

0 points = no drying

6 points = completely dry dishwasher interior

Table 4

Application machine care pen

Example without rinse aid with rinse aid

1 2.3 4.0

2 3.3 3.6

V. Foam development in the pre-rinse cycle

The foam development of the machine operator was determined with the aid of a circulating pressure measuring device. The machine operator was metered in during the cleaning process.

Machine: Miele G 590

Program: 65 ° C normal program

Water: hard 16 ° dH

Dosage: 100 g pen

Here mean:

0 points = no foam development

1 point = weak foaming

2 points = medium foam development (still acceptable)

3 points = strong foaming Table 3

Example 1 2

Foam development in the pre-rinse cycle 2 2

Claims

claims 1. pens for the care of unloaded dishwashers, characterized in that they are a solidified mixture of wax, non-ionic surfactants, water-soluble polyhydric alcohols, water-soluble organic, mono- or polybasic, optionally substituted by hydroxyl groups, carboxylic acids with 2 to 6 carbon atoms in the molecule and, if appropriate, dyes and / or fragrances, contain small amounts of solubilizers for these and corrosion inhibitors, and the nonionic surfactants consist entirely or in substantial part of at least 50% by weight of nitrogenous compounds. 2. Pencils according to claim 1, characterized in that as waxes about 45 to 95, preferably about 50 to 90 wt .-% of a polyethylene glycol with an average molecular weight MG of 1,000 to 12,000, preferably from 3,000 to 6,000 and a softening point from 40 ° C to 60 ° C, preferably from 45 ° C to 55 ° C are included. 3. pens according to claim 1 and 2, characterized in that as nitrogen-containing nonionic surfactants fatty acid-N (R) -polyhydroxyalkylamides, in particular fatty acid-N (R) -glucamides of the general formula R - CH ₂ -C0-N (R) -CH2 (CH0H) 4-CH20H with R = H, -CH3, -C2H5, -C3H7, -C4H9 and ^R l ⁼ C _n H2n + lι ^where ' ^3e ^ ^{n = about} 8 to 16 are contained , the total amount of nonionic surfactants being about 0.5 to 15, preferably from about 1 to 10,% by weight and the quantitative ratio of fatty acid amides to other nonionic surfactants being about 2: 0 to 1: 1. 4. pens according to claim 1 to 3, characterized in that glycerol is contained as water-soluble polyhydric alcohol. 5. pens according to claim 1 to 4, characterized in that about 5 to 50, preferably about 10 to 40 wt .-% anhydrous citric acid is contained as carbonic acid. 6. A method for producing pens according to claim 1, characterized gekenn¬ characterized in that the organic carboxylic acid is stirred into the heated and liquefied wax to its melting point, then the (the) nonionic (s) surfactant (s), the water-soluble polyvalent Alcohol and, if appropriate, the colorants and / or fragrances, a solvent for this and a corrosion inhibitor, with stirring, which still pours hot mass into sleeves lined with a protective film, solidify, the protective film being closed automatically. 7. A process for the production of pens according to claim 1, characterized in that the organic carboxylic acid, the (non) ionic (s) surfactant (s), the water-soluble polyhydric alcohol and, if appropriate, the coloring and / or fragrances, a solubilizer therefor and a corrosion inhibitor mechanically dispersed in the melted wax matrix, the liquid mass is poured into a mold coated with a release agent, the cooled stick mass is removed from the mold and packaged in a protective film. 8. Use of the pens according to claim 1, characterized in that if necessary after partial removal of the protective film with the pen strokes over rubber sealing parts of the machine, then the film is completely removed, the remaining pen is left in the loading space and then the usual cleaning program with the otherwise unloaded machine can run. 9. Use of the pens according to claim 1 and 7, characterized in that one can follow the care process taking place in the cleaning cycle still a rinse cycle equipped with a rinse aid.