WO1997041198A1

WO1997041198A1 - Process for cleaning plastic surfaces and means for carrying out the process

Info

Publication number: WO1997041198A1
Application number: PCT/EP1997/001991
Authority: WO
Inventors: Heinz-Dieter Soldanski; Marianne Duhan
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1996-04-29
Filing date: 1997-04-21
Publication date: 1997-11-06
Also published as: DE59702086D1; EP0900263A1; ATE194999T1; DE19617096A1; EP0900263B1; ES2149589T3

Abstract

This invention concerns a process in which surfaces are moistened with an aqueous cleaning agent which contains synthetic surfactant, water soluble solvent, alkali and soap and polyethylene wax and, simultaneously or subsequently, are wiped with a cloth whereby the dirt is removed with the cleaning agent. This process is characterized by high cleaning effectiveness and little tendency of the cleaned surfaces to become resoiled.

Description

"Process for cleaning plastic surfaces and means for carrying out the process"

The present invention relates to a method for cleaning plastic surfaces with the aid of aqueous cleaning agents and relates in particular to the cleaning of outside surfaces. The invention further relates to agents which are suitable for this method.

Surfaces of plastic objects that are located outdoors and are therefore more or less exposed to natural weathering and the associated pollution, particularly tend to accumulate and turn gray to dirt and dust particles on the surface. This effect is particularly noticeable on light-colored plastic surfaces and regardless of whether the plastic objects are part of a building, such as window frames, doors or shutters, or whether they are independent objects, such as garden furniture. The dirt adheres particularly firmly to these surfaces and is very difficult and usually incomplete to remove using commercially available cleaning agents. In general, dirt accumulates very quickly after cleaning. These difficulties occur with all conventional aqueous cleaning agents that are recommended for this purpose. Common components of such cleaning agents are surfactants and water-soluble solvents and alkalis. The attempt to add dirt-repellent components, such as are known from the floor care sector, for example in the form of special polymers or waxes, did not lead to the desired result. Surprisingly, it has now been found that when using special waxes together with soaps, a very good primary cleaning result combined with a drastically reduced tendency to re-soiling is achieved.

The invention therefore relates to a process for cleaning plastic surfaces, particularly outdoors, in which the surface to be cleaned contains, with an aqueous agent, the synthetic surfactant, water-soluble solvent, alkali, and soap and wax from the group consisting of polyethylene, oxidized polyethylene and mixtures thereof , is wetted, and at the same time or immediately afterwards, the dirt is removed from the surface by wiping together with cleaning agents. Particularly advantageous effects are achieved with waxes whose dropping point is between 100 and 150 ° C., preferably between 120 and 140 ° C. The procedure is remarkably simple and can be carried out without any additional aids, and there is usually no need for rinsing with water.

The agents used in the process according to the invention for cleaning the plastic surfaces contain, as the predominant constituent, water, which serves as a solvent or carrier medium for the cleaning-active substances and other auxiliaries dissolved or dispersed in the agents.

Suitable surfactants for the cleaning agents used according to the invention are in principle all water-soluble surfactants from the classes of anionic, nonionic and zwitterionic surfactants, either individually or as a combination of several surfactants. Anionic and nonionic surfactants and in particular mixtures of surfactants from these two classes are preferred. The synthetic surfactants are primarily of the sulfonate and sulfate type. The surfactants of the sulfonate type are alkylbenzenesulfonates with a C ₉ -C ₁₅ -alkyl radical and olefin sulfonates, ie mixtures of alkene and hydroxyalkanesulfonates and disulfonates, such as are obtained, for example, from C ₁₂ -C ₁₈ monoolefins with a terminal or internal double bond by sulfonating with gaseous Sulfur trioxide and subsequent alkaline or acidic hydrolysis of the sulfonation products is considered. Also suitable are the alkanesulfonates which are obtainable from C ₁₂ -C ₁₈ -alkanes by sulfochlorination or sulfoxidation and subsequent hydrolysis or neutralization or by bisulfite addition to olefins, and the esters of α-sulfofatty acids, for example the α-sulfonated methyl¬ or ethyl esters of hydrogenated coconut, palm kernel or tallow fatty acids.

Suitable surfactants of the sulfate type are the sulfuric acid monoesters, also known as alkyl sulfates, of long-chain, preferably primary alcohols of natural or synthetic origin, ie of fatty alcohols, such as, for. As coconut fatty alcohols, oleyl alcohol, lauryl, myristyl, palmityl or stearyl alcohol, or the C ₁₀ -C ₂₀ oxo alcohols or secondary alcohols of this chain length. The sulfuric acid monoesters of the aliphatic long-chain primary alcohols or ethoxylated secondary alcohols ethoxylated with 1 to 6 mol of ethylene oxide (EO) are also suitable (alkyl ether sulfates). Also suitable are sulfated fatty acid alkanolamides, sulfated fatty acid monoglycerides, long-chain sulfosuccinic esters and the salts of long-chain ether carboxylic acids, which are obtainable, for example, by reacting long-chain alcohols ethoxyated with 1 to 10 mol EO with chloroacetic acid. The anionic surfactants are preferably used as alkali salts, in particular sodium salts, but ammonium salts or the salts of alkanolamines having 2 to 6 carbon atoms can also be used. In the context of the present inventions, particularly preferred anionic surfactants are the alkyl sulfates and the alkyl ether sulfates. Suitable nonionic surfactants are primarily the adducts of 3 to 20 moles of ethylene oxide (EO) with primary C ₁₀ -C ₂₀ alcohols, such as. B. on coconut or tallow alcohols, on oleyl alcohol, on oxo alcohols or on secondary alcohols of this chain length. In addition to the water-soluble nonionic surfactants included here, the not fully water-soluble, low ethoxylated fatty alcohol polyglycol ethers with 3 to 7 ethylene glycol ether residues in the molecule may also be of interest, especially if they are used together with water-soluble nonionic or anionic surfactants. The corresponding ethoxylation products of other long-chain compounds are also suitable, for example the fatty acids and the fatty acid amides with 12 to 18 carbon atoms and the alkylphenols with 8 to 16 carbon atoms in the alkyl part. Instead of part of the ethylene oxide, propylene oxide (PO) can also be added to all of these products. Other suitable nonionic surfactants are also the water-soluble adducts of ethylene oxide with polypropylene glycol, alkylenediamine polypropylene glycol and with alkylpolypropylene glycol with 1 to 10 carbon atoms in the alkyl chain, in which the polypropylene glycol chain is a hydrophobic chain, in which the polypropylene glycol chain is hydrophobic Rest acts. Also suitable as nonionic surfactants are mono- and diethanolamides of fatty acids and N-polyhydroxyalkyl fatty acid amides and long-chain amine oxides or sulfoxides, for example the compounds N-coconut alkyl-N, N-dimethylamine oxide, N-tallow alkyl-N, N-dihydroxyethylamine oxide and also the water-soluble ones Alkyl glycosides, the hydrophobic C ₈ -C ₂₀ alkyl residue of which is usually linked with a mostly oligomeric hydrophilic glycoside residue, for example C ₁₂ -C ₁₄ fatty alcohol + 1, 6 glucose. In the agents used according to the invention, preferred nonionic surfactants are ethoxylates of fatty alcohols or oxo alcohols with 4 to 15 moles of EO, in particular with 4 to 6 moles of EO. The zwitterionic surfactants are long-chain compounds whose hydrophilic part consists of a cationically charged center (usually a tertiary amino or a quaternary ammonium group) and an anionically charged center (usually a carboxylate or a sulfonate group). Examples of such surfactants are N-cocoalkyl-N, N-dimethylaminoacetate and N-dodecyl-N, N-dimethyl-3-aminopropanesulfonate.

The amount of synthetic surfactants in the agents used according to the invention is preferably about 1 to 10% by weight and in particular about 3 to 7% by weight. If a preferred combination of anionic and nonionic surfactants is used as the surfactant, again a combination of alkyl sulfate and alkyl ethoxylate being particularly preferred, the ratio of anionic to nonionic surfactant in this combination is preferably between 1: 2 and 2: 1.

The water-soluble solvents contained in the cleaning agents used should have a water solubility of at least 1% by weight, preferably at least 2% by weight at room temperature. Furthermore, only those solvents are generally used which, when mixed with water, do not dissolve the usual plastics used as construction materials, such as PVC, polycarbonate, impact-resistant polystyrene, and polypropylene and polyamide. Particularly preferred solvents are glycol ethers with up to 10 C atoms in the molecule and alcohols with up to 4 C atoms in the molecule. Examples of suitable glycol ethers are the monoalkyl ethers of monoethylene glycol, diethylene glycol, triethylene glycol, monopropylene glycol and dipropylene glycol with 1 to 6 C atoms, preferably 1 to 4 C atoms in the alkyl part. Of these, diethylene glycol monobutyl ether, ethylene glycol monophenyl ether, propylene glycol monobutyl ether and dipropylene glycol imonomethyl ether are particularly preferred. In the case of alcohols, particular mention should be made of ethanol, n-propanol and isopropanol, of which ethanol in particular is particularly is preferred. Of course, mixtures of several solvents can be used in the agents used according to the invention. When selecting the water-soluble solvents, in addition to the cleaning action, toxic and olfactory properties may also have to be taken into account. The content of water-soluble organic solvents in the agents used according to the invention is preferably between about 2 and 30% by weight, in particular between about 5 and 15% by weight.

The agents used in the process according to the invention have an at least weakly alkaline pH due to the obligatory soap content. The pH of the compositions is preferably between about 9 and about 12, but pH values below or above these values are also possible without further ado. To enhance the cleaning action, the agents contain small amounts of free alkalis in the molecule in the form of ammonia and / or alkanolamines having 2 to 9 C atoms, preferably 2 to 6 C atoms. Ammonia is particularly preferred as an alkalizing agent. In addition to the aminic alkalizing agents, small amounts of alkali metal hydroxides, in particular NaOH and / or KOH, can also be present. The amount of alkalis in the agents used according to the invention is preferably between about 0.1 and 5% by weight, in particular between about 0.2 and 2% by weight. These amounts are understood to be without the alkalis bound in salt-like form in the soaps or the anionic surfactants.

The soaps contained in the agents used according to the invention are water-soluble salts of long-chain fatty acids. Preferred are the salts of fatty acids with 8 to 18 carbon atoms and the salts which are formed with the alkali cations and the ammonium ions derived from ammonia or the ethanolamines with up to 6 C atoms in the molecule. Sodium, potassium and ammonium soaps are particularly preferred. Of course Mixtures of different soaps can also be contained in the agents used according to the invention. The amount of soaps in these agents is preferably about 0.1 to 5% by weight, in particular about 0.3 to 2% by weight.

Another essential constituent in the agents used according to the invention is wax from the group of polyethylene waxes and oxidized polyethylene waxes. Waxes of this type or mixtures of these two types are preferably used which have dropping points between 100 and 150 ° C., in particular between 120 and 140 ° C. The acid number of the oxidized polyethylene waxes is preferably up to about 40. In combination with the soaps also contained in the compositions, these waxes make a significant contribution to the excellent re-soiling behavior when using the method according to the invention. Insofar as they are self-emulsifying, the waxes can be emulsified under pressure into the agents according to the invention. However, the waxes are preferably used for the preparation of the cleaning agents in a pre-emulsified form, as are customary in the trade. Examples of suitable wax emulsions are, for example, Polygen WE1 (BASF, Ludwigshafen, DE), Tecylen 301 or Tecylen 101 (Trüb Chemie, Ramsen, CH). The wax content, calculated as a solid substance, in the agents used according to the invention is preferably about 0.5 to 10% by weight and in particular about 1 to 5% by weight.

In addition to the abovementioned constituents, the agents used according to the invention can contain further auxiliaries and additives customary in such cleaning agents, provided that the advantages of the method according to the invention are not impaired thereby. Examples of such auxiliaries and additives are dyes, perfume, complexing agents for the hardness formers of water, enzymes, foam inhibitors, foam stabilizers and preservatives. Auxiliaries and additives are usually added in a concentration that guarantees the effect. Depending on Auxiliary and intended effect, this concentration can be very different and is usually between about 0.001% by weight and 1% by weight.

The preparation of the agents used according to the invention has no special features and generally does not require a special sequence when mixing the components. If the soap provided in the compositions is to be formed first of all from fatty acid and alkali, this is expediently done in a portion of the water before adding the other constituents. In the event that no pre-emulsified waxes are to be used, it is expedient for the pressure emulsification to put the alkalis in water.

In the actual cleaning process, the cleaning agents are generally applied undiluted or applied to the plastic surfaces as evenly as possible in a form slightly diluted with water. The surfaces are preferably wetted by spraying the cleaning agents on in liquid or pre-foamed form, for example with the aid of a spray gun. Another possibility is to soak a cloth or an absorbent object, for example a sponge, with the cleaning liquid and then to treat the plastic surface with this object. In any case, it is necessary to wipe the plastic surface with a cloth or other soft, absorbent object after applying the cleaning liquid or, in the latter case, and in this way to take up the loosened dirt together with cleaning liquid in the cloth and with to remove this. From time to time, the cloth is wrung out and, if necessary, rinsed with water or new cleaning fluid and used again to treat the plastic surface. Rinsing the plastic surface with water is not necessary and, on the contrary, can adversely affect the effect achieved according to the invention. Examples

1. The aqueous cleaning agents listed in Table 1 were prepared by mixing the individual components. The compositions according to Examples 1, 2, 3 and 5 are comparative examples, while Examples 4, 6 and 7 are according to the invention.

Furthermore, two commercially available aqueous plastic cleaning agents were included in the tests described below, of which A contained nonionic surfactants as active ingredients and isopropanol and B contained anionic surfactants, alcohol derivatives and phosphoric acid esters as active ingredients.

2. To test the cleaning and re-soiling behavior, the cleaning method according to the invention was tested in comparison with conventional methods on commercially available garden chairs made of white PVC, which were exposed to natural weathering outdoors. For this purpose, four equal areas were divided on these chairs on the back and on the seat with the help of an adhesive tape. Three of these partial areas were each subjected to a cleaning process using the products listed in Table 2, the fourth partial area was cleaned in the same way only with water. For each sub-area, the cleaning process consisted of using a pipette to add 5 ml of the cleaning fluid to a damp, well wrung out cotton cloth and to wipe the sub-area evenly with this cloth, wetting it with the cleaning liquid and at the same time removing the dirt from the cotton cloth . In this way, each chair was treated with a different cleaning agent and compared to water. The chairs cleaned in this way were then exposed to the natural weather and after 14 days visually with regard to the Soiling severity rated. The surfaces soiled by the natural weathering were then cleaned again in the same way as before and exposed again to the weathering for 2 weeks. Now a second visual inspection was carried out.

Table 2 below shows the mean results from both

Samples, in which averaging was also carried out over the soiling areas on the seat and back. The following evaluation applies: o = degree of soiling of the water standard

- = more dirty than standard surface

+ = less soiled than standard surface

++ = much less soiled than standard surface

It is clear from the results listed in Table 2 that a particularly sustainable cleaning effect is only achieved in the cleaning processes using a cleaning agent which contains both soap and a wax based on polyethylene.

Table 1, composition of the means in percent by weight 3 o vo

-j

oβ

• fl O

H vo ~ ue

* • _* ve vo

Table 2, test results

Example degree of soiling after weathering

1

2 +

3 +

4 ++

5

6 ++

7 ++

A

B

Claims

claims

1. A method for cleaning plastic surfaces, in which the surface to be cleaned is wetted with an aqueous agent which contains synthetic surfactant, water-soluble solvent, alkali, and soap and wax from the group consisting of polyethylene, oxidized polyethylene and mixtures thereof, and simultaneously or immediately then the dirt is removed from the surface together with the cleaning agent by wiping.

2. The method according to claim 1, wherein the wax contained in the cleaning agent from the group polyethylene, oxidized polyethylene and mixtures thereof has a dropping point between 100 and 150 ° C, preferably between 120 and 140 ° C.

3. The method according to any one of claims 1 to 2, wherein the synthetic surfactant contained in the cleaning agent is selected from the group anionic surfactants, nonionic surfactants and mixtures thereof.

4. The method according to claim 3, in which the synthetic surfactant contained in the cleaning agent is selected from the group consisting of alkyl sulfates, alkyl ether sulfates, alkyl ethoxylates and mixtures thereof.

5. The method according to any one of claims 1 to 4, wherein the water-soluble solvent contained in the cleaning agent is selected from the group glycol ether with up to 10 carbon atoms in the molecule, alcohols with up to 4 carbon atoms in the molecule and mixtures of these solvents.

6. The method according to claim 5, in which the solvent contained in the cleaning agent is selected from the group consisting of ethylene glycol monophenyl ether, propylene glycol monobutyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, ethanol and mixtures of these compounds.

7. The method according to any one of claims 1 to 6, wherein the alkali contained in the cleaning agent is selected from the group ammonia, alkanolamine with 2 to 9 carbon atoms in the molecule and mixtures of these compounds, and optionally additionally alkali hydroxide is present.

8. Aqueous cleaning agent for carrying out a method according to any one of claims 1 to 7, containing synthetic surfactant, water-soluble solvent, alkali, and soap and wax from the group of polyethylene, oxidized polyethylene and mixtures thereof.

9. Composition according to claim 8, containing

1 to 10% by weight, preferably 3 to 7% by weight, of synthetic surfactant from the group consisting of anionic surfactants, nonionic surfactants and mixtures thereof;

2 to 30% by weight, preferably 5 to 15% by weight of water-soluble

Solvents from the group of glycol ethers with up to 10 C atoms in the molecule, alcohols with up to 4 C atoms in the molecule and mixtures thereof; 0.1 to 5% by weight, preferably 0.2 to 2% by weight, of alkali from the group consisting of ammonia, alkanolamine with 2 to 9 carbon atoms in the molecule and mixtures thereof; 0.1 to 5% by weight, preferably 0.3 to 2% by weight, of water-soluble soap based on fatty acids with 8 to 18 carbon atoms in the molecule;

0.5 to 10 wt .-%, preferably 1 to 5 wt .-% of wax from the group of polyethylene, oxidized polyethylene and mixtures thereof with a dropping point between 100 and 150 ° C.

10. Composition according to claim 9, containing

1 to 10% by weight, preferably 3 to 7% by weight, of synthetic surfactant from the group consisting of alkyl sulfates, alkyl ether sulfates, alkyl ethoxylates and mixtures thereof;

2 to 30% by weight, preferably 5 to 15% by weight of water-soluble

Solvents from the group consisting of ethylene glycol monophenyl ether, propylene glycol monobutyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, ethanol and mixtures thereof,

0.1 to 5 wt .-%, preferably 0.2 to 2 wt .-% of alkali from the group ammonia, ethanolamines with 2 to 6 carbon atoms in the molecule and mixtures thereof;

0.1 to 5 wt .-%, preferably 0.3 to 2 wt .-% of water-soluble soap from the group of alkali, ammonium and amine salts of fatty acids with 8 to 18 carbon atoms and mixtures of these salts;

0.5 to 10% by weight, preferably 1 to 5% by weight, of wax from the group

Polyethylene, oxidized polyethylene and their mixtures with a dropping point between 120 and 140 ° C.

11. Use of an agent according to any one of claims 8 to 10 for cleaning plastic surfaces, preferably outdoors.