EP0642572B1 - Floor cleaning process - Google Patents

Abstract

According to a floor cleaning process, a non-diluted, aqueous surfactant solution is applied on the floor and spread by wiping. The surfactant solution contains a combination of alkyl polyglycoside and alkylether sulphate. This process achieves remarkable cleaning results without leaving visible residues on the floor.

Description

The present invention is in the field of cleaning floors using aqueous surfactant solutions.

Today's most common methods of cleaning and maintaining floors can be divided into three classes:

Processes that primarily aim to care for and preserve the flooring use agents that, after being applied and distributed on the flooring surfaces, produce more or less hard, protective films. For this purpose, the agents usually contain heavy metal salts, mostly in emulsified form, waxes or film-forming polymers and crosslinking agents, which together form self-glossy or polishable films on the treated surfaces after drying. In this way, long-lasting preservation of the surfaces can be achieved, with strong mechanical loads being well tolerated, depending on the quality of the film. A disadvantage of these agents is that removal of the firmly adhering films, if it becomes necessary, for example because of dirt or damage, is only possible under extreme conditions.

In contrast, in processes whose aim is to clean and restore the original surface, agents are used which contain high amounts of surfactants, often together with alkaline substances, organic solvents or abrasives. In many cases, these agents can be used to thoroughly remove dirt and old coverings, but the surfaces cleaned in this way are usually exposed to re-soiling without protection, unless a preservation treatment is connected.

In addition to this process of basic cleaning, in which the old self-gloss coverings are removed, processes are known for superficial cleaning, in which only loosely lying and adhering dirt is removed without the care films being attacked. The agents used contain surfactants only in low concentrations and at most small amounts of alkali. Usually, low concentrations of nourishing substances are contained at the same time, which is why these agents are also referred to as wiping agents. An example of such an agent is described in Japanese Patent Application 3/182596.

With the last-mentioned methods, which also includes the method according to the present invention, a major problem lies in not impairing the other properties of the floor surface, in particular its gloss, with good dirt removal. This problem is often only poorly solved in the processes used today because the cleaning agents used cannot be distributed evenly enough and dry up in strips. In spite of many suggestions in this area, there was therefore still the task of developing an overall more satisfactory process.

The present invention offers a solution to this problem in the form of a method for cleaning floors, in which an aqueous surfactant solution in an amount of 0.2 to 5 g per square meter is applied undiluted to the floor, preferably by spraying, and is distributed there by wiping , wherein this solution contains a surfactant combination of alkyl polyglycoside and alkyl ether sulfate.

The process of spraying and in particular the subsequent wiping of the floor results in a largely uniform distribution of the cleaning agent, so that its effect can develop evenly. The portion of the surfactant solution remaining on the floor after wiping dries on the floor surface so uniformly in an unprecedented manner that no streaks can be seen and the surface gloss remains intact. The high cleaning effect and the property of streak-free drying are decisively determined by the surfactant combination of alkyl polyglycoside and alkyl ether sulfate present in the solution. The alkyl polyglycosides used according to the invention are surfactants of the general formula I.

RO (-G) _n I

in which R is a long-chain alkyl radical having 8 to 22 carbon atoms, G is a glycosidically bonded radical of a monosaccharide and n is a value between 1 and 10.

Alkyl polyglycosides have been known as surface-active substances for more than 50 years and can be produced in various ways. In this context, reference should only be made to European patent application 362 671, which also cites literature on older processes.

A synthesis which is important on an industrial scale today consists essentially in the acid-catalyzed condensation of monosaccharides of the aldose type (HO-G) with long-chain alcohols (R-OH) which contain 8 to 22, preferably 8 to 18, C atoms. When water escapes, alkyl glycosides of the formula I are formed

RO (-G) _n

the value of n can be varied within wide limits by the choice of reaction conditions. Alkyl glycosides of the formula I with n = 1 to 10 can be used according to the invention; Compounds with values for n between 1 and 6, in particular 1 to 2, are preferred. In products in which n is greater than 1, n naturally represents a statistical mean.

In the production of the alkyl glycosides, one can also start from oligosaccharides or polysaccharides, which are then depolymerized to lower fragments in the course of the acid-catalyzed reaction by hydrolysis and / or alcoholysis before the alkyl glycosides of the formula I form. Mixtures of different reducing monosaccharides or polysaccharides which contain different monosaccharide units can also be used as starting materials, and if n is greater than 1, appropriately mixed alkylglycoside molecules can be formed.

The following monosaccharides are preferably suitable as starting materials: glucose, mannose, galactose, arabinose, apiose, lyxose, gallose, old rose, Idose, ribose, xylose and talose, and the oligosaccharides and polysaccharides composed of these monosaccharides, for example maltose, lactose, maltotriose, hemicellulose, starch, partial hydrolysates of starch and sugar syrup. In the context of the invention, however, alkyl glycosides are preferred which are composed of the same monosaccharide units. Alkyl glycosides in which the rest (-G) is derived from glucose are particularly preferred. For these compounds, which are also referred to as alkyl glucosides, glucose, maltose, starch and other oligomers of glucose are used accordingly as starting materials.

In the preparation described above, the alkyl part R is derived from long-chain, optionally unsaturated, preferably primary alcohols which can be branched, but are preferably not branched. Examples are the synthetic oxo alcohols with 9 to 15 C atoms and the fatty alcohols obtained from natural fatty acids with 8 - 22 C atoms. The fatty alcohols with 8 to 18 carbon atoms and the oxo alcohols with 11 to 15 carbon atoms are preferred, but in particular the fatty alcohols with 8 to 10 carbon atoms or with 12 to 14 carbon atoms.

In addition to the actual alkyl glycosides of formula I, technically manufactured products generally also contain certain proportions of free alcohol R-OH and non-acetalized saccharides, optionally in oligomerized form. In most cases, these technical impurities do not interfere with the intended use. If alcohol mixtures are used in the production of the alkyl glycosides, for example alcohols based on natural fats, the alkyl glycosides are of course also mixtures with a correspondingly larger meaning of R in formula I.

The second component used in the surfactant mixture according to the invention is alkyl ether sulfate. Chemically speaking, these are salts of sulfuric acid monoesters of ethoxylated long-chain alcohols with the general formula II

R'-O (-CH ₂ -CH ₂ -O) _m -SO ₄ M II

Alkyl ether sulfates have long been in practical use as surfactants, so that the preparation need not be discussed in more detail here. A common method is the ethoxylation of long-chain alcohols R-OH with m mol of ethylene oxide and subsequent sulfation and neutralization. In formula II, the radical R 'is derived from long-chain, optionally unsaturated, preferably primary alcohols which can be branched, but are preferably not branched. Examples are the synthetic oxo alcohols with 9 to 15 carbon atoms and the fatty alcohols with 8 to 22 carbon atoms obtained from natural fatty acids. Preferred within the scope of the invention are ether sulfates in which R 'is derived from fatty alcohols with 10 to 18 C atoms or from oxo alcohols with 11 to 15 C atoms. The index m indicates the number of moles of ethylene oxide (EO) that are bound in the molecule. The value for m in the ether sulfates which can be used according to the invention is between 1 and 6, preferably between 2 and 4. In the conventional production process which proceeds via the ethoxylation of long-chain alcohols R'-OH, it goes without saying that m is always only an average of several integers can mean. M represents the cation of the base used to neutralize the sulfuric acid half-ester. In the alkyl ether sulfates which can be used according to the invention, M is preferably alkali metal or ammonium, in particular sodium.

The particular advantages of the cleaning process according to the invention are based to a very large extent on the simultaneous use of the alkyl polyglycosides and alkyl ether sulfates in the aqueous cleaning liquor. The weight ratio between alkyl polyglycosides and alkyl ether sulfates is usually between about 1:10 and 10: 1. Weight ratios between 4: 1 and 1: 4 and in particular between 2: 1 and 1: 2 are preferred. Due to the particular interaction of these surfactants, the Cleaning solution required only a low concentration of the surfactant mixture, which is preferably 0.2 to 4 percent by weight and in particular 0.5 to 2 percent by weight.

In addition to the surfactant combination used according to the invention, the cleaning solution usually does not contain any other surfactants, albeit their Presence is not excluded, provided that it does not interfere with the advantageous effect of the mixture of alkyl polyglycosides and alkyl ether sulfates. In contrast, the addition of other cleaning agents and care products can be useful. First of all, water-miscible organic solvents, complexing agents for water hardness, waxes and film-forming polymers should be mentioned. In addition, dyes, fragrances, foam inhibitors and antimicrobial agents as well as acids and bases for regulating the pH are mentioned. It goes without saying that only representatives of these substances are selected in the selection which do not impair the advantageous effects of the surfactant mixture of alkyl polyglycosides and alkyl ether sulfates.

The water-miscible organic solvents which can be used according to the invention are primarily volatile alcohols and ether alcohols. Examples are in particular the lower alcohols with 2 to 4 carbon atoms, of which ethanol is particularly preferred. The content of organic solvents in the cleaning agent solution is generally not more than 20 percent by weight, preferably between 1 and 10 percent by weight.

The use of waxes and / or film-forming polymers in the cleaning agent solution has the purpose of making the thin film remaining on the floor surface more dirt-repellent and, if necessary, to compensate for minor damage to the surface of the floor which impair the gloss. Suitable waxes are both synthetic waxes, such as polyethylene waxes, partially synthetic waxes, such as montan ester waxes, and natural waxes, such as carnauba wax and candelilla wax. According to the invention, natural waxes, in particular carnauba wax, are preferred. The concentration of the waxes in the cleaning solution is usually not more than about 0.3 percent by weight, preferably between 0.05 and 0.2 percent by weight. Suitable polymers are generally all polymer compounds which are soluble in water in the weakly alkaline range and which dry out from solutions with the formation of a film. As a rule, these are copolymers with a certain proportion of monomers containing carboxylic acid groups, in particular acrylic acid or methacrylic acid, which also contain nonionic monomers, in particular from the group of acrylic acid or methacrylic acid esters with lower alcohols and styrene. The content of polymers in the cleaning agent solutions is usually not more than 0.3 percent by weight, preferably between 0.05 and 0.2 percent by weight. Polymeric film formers and waxes can also be present at the same time.

To carry out the method according to the invention, the cleaning agent solution described above is applied in as uniform a form as possible to the floor to be treated and is then immediately distributed by wiping on the floor. The application takes place in a particularly advantageous manner by spraying either with the aid of small hand-held sprayers or, particularly in the commercial sector, with the aid of mechanical spraying devices. The amount to be applied depends within certain limits on the degree of soiling of the floor and its surface roughness. According to the invention, it lies in the range between 0.2 g and 5 g / m ² and in particular between approximately 0.3 and 2 g / m ² . The wiping is preferably carried out with a damp, absorbent soft object, in particular with a cloth, a sponge or a mop. While wiping the detergent solution is evenly distributed over the entire surface, on the other hand the loosened dirt together with excess detergent solution is absorbed by the absorbent object. From time to time, the absorbent article is rinsed out in clear water, the absorbed dirt and excess surfactant solution being released. Larger areas can be cleaned in sections to prevent the sprayed-on cleaning solution from drying too much. In addition to excellent cleaning action and the avoidance of streaking on the surfaces, the method according to the invention is also distinguished by ecological advantages. By applying the detergent solution directly to the surface of the floor to be cleaned, only the minimum amount necessary for cleaning is used, whereas with conventional wiping cleaning, the detergent was diluted in the water bucket, so that a large proportion of the wiping water always reached the sewage system unused .

Examples

• 1. Rückstandsverhalten
  Ein Fußbodenstück der Größe 75 x 60 cm, das mit schwarzen hochglänzenden Kacheln belegt war, wurde zur Hälfte mit dem Reinigungsmittel behandelt und nach dem Abtrocknen visuell durch drei Prüfer abgemustert. Zur Durchführung des Reinigungsverfahrens wurden auf die zu behandelnde Hälfte des Fußbodenstückes mit einer Glaspipette 0,2 ml des jeweiligen Reinigungsmittels aufgebracht und dieses Mittel mit einem feuchten, gut ausgewrungenen Baumwolltuch (25 x 25 cm) durch Wischen gleichmäßig verteilt. Dieser Vorgang wurde, um eine Akkumulation des Reinigungsmittels beobachten zu können, nach Zwischentrocknung des verbleibenden feuchten Reinigungsmittels viermal mit einem frischausgespülten Tuch wiederholt. Nach dem Antrocknen des letzten Auftrags wurde die Bewertung durchgeführt, wobei nach Absprache der Prüfer folgende Bewertungsziffern vergeben wurden:

  1 =

  kein sichtbarer Unterschied zwischen behandelter und nichtbehandelter Fläche

  2 =

  leichte Streifenbildung

  3 =

  stärkere Streifenbildung

  4 =

  deutlicher, flächig sichtbarer Rückstand

• 1a. Rückstandsverhalten bei Anwendung der Mittel im herkömmlichen Reinigungsverfahren (Wassereimer-Methode)
  In einem Wassereimer wurde eine Mischflotte dadurch hergestellt, daß 10 g der jeweiligen Mittel pro Liter Leitungswasser (Wasserhärte 25°d) aufgelöst wurden. Mit dieser Lösung wurde ein Baumwolltuch der Größe 25 x 25 cm getränkt und dann das tropfnasse Baumwolltuch zum Wischen der unter 1. beschriebenen Fläche benutzt. Das Tuch wurde dann ausgewrungen und die Fläche einmal mit diesem Tuch nachgewischt. Wie unter 1. angegeben wurde der Wischvorgang jeweils nach dem Abtrocknen der Fläche viermal wiederholt. Die visuelle Bewertung entspricht der unter 1.
• 2. Reinigungsvermögen nach Gardner (nicht erfindungsgemäß)
  Die Prüfung erfolgte in der für Wischpflegemittel in der Zeitschrift "Seifen-Öle-Fette-Wachse" 1986 S. 371-72 angegebenen Weise an weißen, künstlich angeschmutzten PVC-Platten der Größe 40 x 554 mm. Als Anschmutzung diente das dort angegebene Gemisch aus 7% Ruß, 57% Fettsäuretriglycerid und 36% Benzin. Es wurde in Variante a auf unbehandelte PVC Streifen aufgetragen, während in Variante b PVC-Streifen angeschmutzt wurden, die mit dem Reinigungsmitteln vorbehandelt worden waren. Diese Vorbehandlung, die zur Überprüfung eines schmutzabweisenden Effektes vorgenommen wurde, geschah in der Weise, daß die Fläche von 7 eng nebeneinander liegenden Streifen mit einer Gesamtfläche von 280 x 554 mm mit 5 ml des jeweiligen Reinigungsmittels versehen und dann mit einem feuchten Baumwollappen (25 x 25 cm) gleichmäßig gewischt wurde. Nach dem Abtrocknen wurde diese Behandlung noch zweimal wiederholt, ehe dann die Anschmutzung aufgetragen wurde.

The cleaning effect and residue behavior were tested on the following agents 1 and 2 according to the invention and in the same way also on agents 3 to 6 not according to the invention. The composition of the agents is shown in Table 1 (data in percent by weight). Table 1 ingredients Examples 1 2nd 3rd 4th 5 6 Ethanol 5.0 5.0 5.0 C ₁₂ -C ₁₄ fatty alcohol sulfate Na 0.58 C ₁₂ -C ₁₄ fatty alcohol ether sulfate Na (2 EO) 0.5 0.5 0.5 Coconut alcohol ethoxylate (4 EO) 0.5 0.5 sec. C _13/18 alkanesulfonate Na 1.0 1.0 C ₈ -C ₁₀ alkyl polyglucoside (n = 1.6) 0.5 0.5 Carnauba wax 0.1 0.1 0.1 0.1 Perfume 0.1 0.1 0.1 0.1 0.1 0.1 Glutaraldehyde 0.2 0.2 0.2 0.2 0.2 0.2 100% water Residue behavior and cleaning effect were tested on different floor coverings under different conditions:

• 1. Residue behavior
  A 75 x 60 cm piece of flooring with black high-gloss finish Tiles were covered, half was treated with the cleaning agent and visually checked by three inspectors after drying. To carry out the cleaning process, 0.2 ml of the respective cleaning agent was applied to the half of the floor piece to be treated with a glass pipette and this agent was evenly distributed with a damp, well wrung out cotton cloth (25 x 25 cm). In order to be able to observe an accumulation of the cleaning agent, this process was repeated four times with a freshly rinsed cloth after the remaining moist cleaning agent had dried. After the last order had dried on, the evaluation was carried out, with the following evaluation numbers being assigned after the examiners' agreement:

  1 =

  no visible difference between treated and untreated surfaces

  2 =

  slight streaking

  3 =

  stronger banding

  4 =

  clear, area-visible residue

• 1a. Residue behavior when using the agents in the conventional cleaning process (water bucket method)
  A mixing liquor was prepared in a water bucket by dissolving 10 g of the respective agent per liter of tap water (water hardness 25 ° d). A 25 x 25 cm cotton cloth was impregnated with this solution and the dripping wet cotton cloth was then used to wipe the area described under 1. The cloth was then wrung out and the surface wiped once with this cloth. As stated under 1., the wiping process was repeated four times each time the surface had dried. The visual assessment corresponds to that under 1.
• 2. Gardner cleaning power (not according to the invention)
  The test was carried out in the manner specified for wiping agents in the magazine "Seifen-Öle-Fette-Wwachs" 1986 pp. 371-72 on white, artificially soiled PVC sheets of size 40 x 554 mm. As soiling served the mixture of 7% carbon black, 57% fatty acid triglyceride and 36% gasoline specified there. In variant a, it was applied to untreated PVC strips, while in variant b PVC strips that had been pretreated with the cleaning agent were soiled. This pretreatment, which was carried out to check a dirt-repellent effect, was carried out in such a way that the area of 7 strips lying closely next to one another with a total area of 280 x 554 mm was given 5 ml of the respective cleaning agent and then with a damp cotton cloth (25 x 25 cm) was wiped evenly. After drying, this treatment was repeated two more times before the soiling was applied.

In the actual cleaning cycle, which was carried out with a mechanically operated sponge, the amount of cleaning agent was 6 ml per strip. The evaluation of 7 strips, each treated in the same way, was carried out with a Lange color difference measuring device Microcolor, which gave the results in percent cleaning effect (based on the white, untreated film = 100).

The results obtained with the individual agents in the above test methods are summarized in Table 2. Agents 1a and 2a listed there were concentrates which contained surfactants and wax in the same proportions as agents 1 and 2, but in a concentration 10 times higher. Table 2 Test method Examples 1 2nd 1a 2a 3rd 4th 5 6 1st residue on black tiles a) Concentrated (according to the invention) 1 1 2nd 2nd 2-3 2-3 b) Dilution 10 g / l 3rd 3rd 2. Gardner cleaning ability a) not pretreated 57 58 54 51 49 50 b) pretreated 74 59 70 68 68 52

It is clear from the values in Table 2 that an excellent cleaning result is achieved with the process according to the invention and, at the same time, residues on the cleaned surfaces are practically not recognizable.

Claims (6)

1. A process for cleaning floors using alkyl ether sulfates, characterized in that an aqueous surfactant solution is applied to the floor in undiluted form in a quantity of 0.2 to 5 g per square metre and is distributed over the floor by wiping, the surfactant solution containing a combination of alkyl polyglycoside and alkyl ether sulfate.
2. A process as claimed in claim 1, in which the surfactant solution additionally contains a water-miscible, volatile organic solvent.
3. A process as claimed in claim 1 or 2, in which the surfactant solution contains 0.2 to 4% by weight of a surfactant mixture of alkyl polyglycoside and alkyl ether sulfate.
4. A process as claimed in any of claims 1 to 3, in which alkyl polyglycoside and alkyl ether sulfate are present in the surfactant solution in a ratio by weight of 4:1 to 1:4 and preferably 2:1 to 1:2.
5. A process as claimed in any of claims 1 to 4, in which the surfactant solution additionally contains a floor-care substance from the group of waxes, film-forming polymers and mixtures thereof.
6. A process as claimed in any of claims 1 to 5, in which the surfactant solution is applied by spraying, preferably in a quantity of 0.3 to 2 g per square metre.