NO174430B - Aqueous cleanser for hard surfaces - Google Patents

Description

The present invention relates to a cleaning agent for hard surfaces, such as bathtubs, wash basins, tiles, porcelain and enamelware, as the cleaning agent removes soap scum, lime deposits and grease from such surfaces without damaging them. The invention relates more particularly to an acidic microemulsion which can be sprayed onto the surface to be cleaned and which can be wiped away without ordinary rinsing and still leave the cleaned surface glossy and shiny.

Cleaners for hard surfaces, such as bathroom cleaners and scouring cleaners, have been known for many years. Abrasive cleaners normally include a soap or a synthetic organic surfactant or surfactant and an abrasive. Such products can scratch relatively soft surfaces and can eventually cause them to become dull. They are also often ineffective when it comes to removing limescale deposits

(usually shell formations of calcium and magnesium carbonate)

during normal use. Because scale deposits can be removed by chemical reactions with acidic media, various acidic cleaners have been produced and have had varying degrees of success.

In some cases, such cleaners have been a failure because the acid used was too strong and damaged the surfaces being cleaned. At other times, the acidic component in the cleaning agent reacted in an undesirable way with other components in the product and adversely affected, for example, the surfactant or the perfume. Certain cleaning products require rinsing to avoid unwanted deposits being left on the surface. the cleaned surfaces. As a result of research carried out in an attempt to overcome the aforementioned disadvantages, an improved liquid detergent mixture has recently been produced in stable microemulsion form which is an effective detergent for removing soap scum, scale and greasy dirt from hard surfaces, such as bathroom surfaces, and which does not require rinsing after use. Such a product has been described in US Patent Application No. 120,250 which was filed on November 12, 1987 by Loth, Blanvalet and Valange,

and this patent application is hereby incorporated by reference. In particular, in example 3 of this patent application, an acidic, clear oil-in-water microemulsion is described, which is stated in the patent application with good results to be able to be used to clean shower wall tiles

for scale and soap scum that have stuck to the tiles. Such cleaning was carried out by applying the cleaning agent to the walls, followed by wiping or minimal rinsing, after which the walls were allowed to dry to achieve a good shiny appearance.

The described microemulsion cleaning agent according to the patent application is effective in removing scale and soap scum from hard surfaces, and it is easy to use, but it has been shown that its mixture of acidic agents (succinic, glutaric and adipic acids) can damage the surfaces of some hard fixtures, such as those made of materials that are not acid-resistant. One such material is an enamel which has been widely used in Europe as a coating for bathtubs and which will be referred to here as "European enamel". This has been described as a white zirconium enamel or a white zirconium powder enamel and offers the advantage that it is resistant to surfactants, and this makes it suitable for use on bathtubs, wash basins, shower tiles and enamelware in bathrooms. However, such an enamel is sensitive to acids and is seriously damaged when the acidic microemulsion cleaner based on the three previously balanced organic carboxylic acids is used. This problem has been solved by means of the present invention according to which additional acidic materials are incorporated into the cleaning agent together with the organic acids, and instead of aggravating the problem, they prevent damage to such European enamel surfaces due to such organic acids. Furthermore, a mixture of such additional acids, phosphonic and phosphoric acid, surprisingly improves the safety of using the aqueous cleaner on such European enamel surfaces further and lowers the cost of the cleaner. Thanks to the present invention, the emulsion according to the invention can thus be used to clean European enamel surfaces as well as any other acid-resistant surfaces of bathtubs and other bathroom surfaces. However, the product should not be used on various other materials that are particularly sensitive to attack by acidic media, such as marble.

The invention thus relates to an acidic, aqueous cleaning agent for bathtubs and other objects with hard surfaces that are acid-resistant or made of zirconium white enamel, as the cleaning agent has a pH of 1-4 and removes scale, soap scum and greasy dirt from the surfaces of such objects without damaging such surfaces, and the cleaning agent is characterized by the fact that it comprises 2-8% of a synthetic organic anionic surfactant or surfactants selected from the group consisting of water-soluble salts of lipophilic sulphonic and sulfuric acids, 1-6% of a synthetic organic non-ionic surfactant or surfactants selected from the group consisting of condensation products of ethylene oxide or ethylene glycol with a lipophilic part which is a higher alcohol, phenol, propylene oxide polymer or propylene glycol polymer, 2-10% of an aliphatic carboxylic diacid or diacids of 4-7 carbon atoms, 0.05-1% phosphoric acid and 0.01-0.2% of an aminoalkylenephosphonic acid or

-acids with the formula

in which Y is alkylamino or N-substituted alkylamino, the aminoalkylenephosphonic acid containing 1-3 amino nitrogens, 3

or 4 lower alkylenephosphonic acid groups in which the lower alkylene has 1 or 2 carbon atoms, and 0-2 alkylene groups each with 2-6 carbon atoms, the alkylene group(s) being present and connecting amino nitrogens when several such amino nitrogens are present in the aminoalkylenephosphonic acid.

In the present mixtures, the synthetic organic anionic surfactants are water-soluble salts of lipophilic sulfonic and sulfuric acids. The lipophilic moieties preferably include long-chain aliphatic groups, preferably long-chain alkyl groups, with 8-20 carbon atoms and more preferably

with 12-18 carbon atoms. Although many

different types of solubilizing cations may be present in the surfactants, it will usually be preferred that these consist of alkali metal, e.g. sodium or potassium or a mixture thereof, ammonium or lower alkanolamine with 2 or 3 carbon atoms per alkanol moiety. It is a desired feature according to the present invention that sodium can be the alkali metal used, and the emulsions obtained will be stable and effective.

Strongly preferred salts of lipophilic sulphonic acids are paraffin sulphonates in which the paraffin group has 12-18 carbon atoms, preferably 14-17 carbon atoms. Other useful sulphonates are olefin sulphonates in which the olefin starting material has 12 - 18 carbon atoms, e.g. 12 - 15 carbon atoms, and linear alkyl-benzene sulphonates in which the alkyl group has 12 - 18 carbon atoms, preferably 12 - 16 carbon atoms, e.g. 12 or 13 carbon atoms. All such sulphonates will preferably be used in the form of their sodium salts, but other salts are also effective.

Strongly preferred salts of lipophilic sulfuric acids are of higher alkyl ethoxylate sulfuric acids which can also be termed higher alkyl ethyl ether sulfuric acids. The higher alkyl groups of such compounds have the chain lengths indicated above for this group of anionic surfactants, ie 10 - 18 carbon atoms, preferably 10 - 14 carbon atoms, e.g. 12 or approx. 12 carbon atoms. Such compounds should include 1-10 ethylene oxide groups per molecule, preferably 3-7 ethylene oxide groups per molecule, e.g. 5. A preferred cation is sodium, but the cations mentioned above, due to their solubilizing functions, can be used under suitable circumstances.

The non-ionic surfactants which can be used according to the present invention are condensation products of a lipophilic part which is a higher alcohol, phenol, propylene glycol polymer. or propylene oxide polymer, with ethylene oxide or ethylene glycol. In some of the condensation products of ethylene oxide and higher fatty alcohol or alkyl-substituted phenol (in which the alkyl group on the phenol nucleus usually has 7-12, preferably 9, carbon atoms) part of the propylene oxide can be mixed with the ethylene oxide so that the lower alkylene oxide part of the non-ionic surfactant is mixed, whereby the hydrophilic-lipophilic balance (HLB) can be regulated.

Strongly preferred nonionic surfactants present in the emulsions according to the invention will be condensation products of a fatty alcohol having 8-20 carbon atoms, with 3-20 moles of ethylene oxide, preferably of a linear alcohol having 9-15 carbon atoms, such as 9-11 or 11 ^ 13 carbon atoms, or an average of 10 or 12 carbon atoms, with 3-15 mol

ethylene oxide, such as 3-7 or 5-9 moles of ethylene oxide, e.g. about.

5 or 7 moles of this. Instead of the higher fatty alcohol, an alkylphenol can be used, such as an alkylphenol with 8-10 carbon atoms in a linear alkyl group, e.g. nonylphenol, and the phenol may be condensed with 3-20 ethylene oxide groups, preferably 8-15. Similar functioning, non-ionic surfactants which are polymers of mixed ethylene oxide and propylene oxide can at least partially be used as a substitute for the other non-ionic surfactants. Among these are those sold under the Plurafac<®> brand, such as Plurafac<®> RA-30 and Plurafac<®> LF-400. Preferred such nonionic surfactants contain 3-10 ethoxy groups, more preferably approx. 7, and 2 - 7 propoxy groups, more preferably approx. 4, and these are condensed with a higher fatty alcohol having 12 - 16, more preferably 13 - 15, carbon atoms, so that one mole of non-ionic surfactant is obtained.

Various non-ionic surfactants, and the anionic surfactants, are often mixtures, and these are included under the designations given here in the singular.

The active acidic component in the emulsions is carboxylic diacid, which is sufficiently strong to lower the emulsion's pH to within the range from 1 to 4. Among the carboxylic acids, the diacids have proven to be the most effective for removing soap scum and scale from bathroom surfaces without destabilizing the emulsion. Within the dicarboxylic acid group, which includes those with 2-10 carbon atoms. from oxalic acid via sebacic acid, suberic, azelaic and sebacic acids have lower solubility and are therefore not as useful in the present emulsions as the other dibasic aliphatic fatty acids which are all preferably saturated and straight chain. Oxalic and malonic acids, although they are also useful here as reducing agents, can be too strong for careful cleaning of hard surfaces. Preferred such dibasic acids are those having a number of carbon atoms within the middle part of the 2 - 10 carbon atom acid range, succinic, glutaric, adipic and pimelic acids, especially the first three of these, which fortunately are commercially available, in mixture. The diacids, after they have been incorporated into the emulsion according to the invention, can be partially neutralized to give the desired pH in the emulsion in order to achieve the strongest functional efficiency with certainty.

Phosphoric acid is one of the additional acids that help to protect acid-sensitive surfaces that are cleaned with the emulsion cleaner according to the invention. Being a tri-basic acid, this can also be partially neutralized to obtain

an emulsion pH within the desired range. For example, it can be partially neutralized to the biphosphate, e.g. NaH 2 PO 4 or NH 4 H 2 PO 4 . ^

Phosphonic acid, the second of the two additional acids to protect acid-sensitive surfaces against the dissolving action of the dicarboxylic acids in the present emulsions, apparently exists only theoretically, its derivatives are stable and useful in the practice of the present invention. These are considered as if they are phosphonic acids in the sense that this term is used in the present description.

The phosphonic acids give the hair structure

wherein Y is alkylamino or N-substituted alkylamino. For example, a preferred phosphonic acid component in the present emulsions is aminotrismethylenephosphonic acid having the formula NfCH^P^O^). Among other useful phosphonic acids are ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid and diethylenetriaminepentamethylenephosphonic acid. Such a group of compounds is described as aminoalkylenephosphonic acid containing 1-3 aminonitrogen atoms, 3 or 4 lower alkylenephosphonic acid groups in which the lower alkylene group has 1 or 2 carbon atoms, and 0-2 alkylene groups with 2-6 carbon atoms in each, this alkylene or these alkylenes is present and connects the amino nitrogen atoms when several such amino nitrogen atoms are present in the aminoalkylenephosphonic acid. It has been shown that such aminoalkylene phosphoric acids, which can also be partially neutralized at the microemulsion cleaning agent's desired pH, have the desired stabilizing and protective effect in the cleaning agent according to the invention, especially when they are present together with phosphoric acid, whereby harmful attacks on European enamel are prevented

surface due to the diacid(s) components in the cleaning agent. As a rule, the phosphoric acid salts will be monosalts of each

of the phosphorus and/or phosphonic acid groups present.

The water used for the production of the present microemulsions can be tap water, but it preferably has a low hardness, and this is normally less than 150 parts per litre. million (ppm) hardness, calculated as calcium carbonate. Good cleaning agents can nevertheless be produced from tap water that has a higher hardness, up to 300 ppm, such as CaCO^. It is most preferred that the water used is distilled or deionized water in which the content of hardness ions is less than 25 ppm and as a rule zero. Use of such deionized water makes it possible to produce a product with consistently good qualities regardless of hardness variations in the aqueous medium.

Various other components can in the desired way

be present in the cleaning agents according to the invention, including preservatives, antioxidants or corrosion inhibitors, co-solvents, co-surfactants, polyvalent metal ions, perfumes, dyes and terpenes (and terpineols), but various other auxiliary substances which are commonly used in liquid detergent mixtures and cleaning agents for hard surfaces, may also be present, provided that they do not adversely affect the detergent's cleaning and foam and scale removal functions. Among the various auxiliaries (which are identified as such because they are not necessary for the production of an effective cleaning agent even though they may be highly desired components of the cleaning agent) the more important are considered to be the perfumes

as together with terpenes, terpineols and hydrocarbons

(which can be used as a substitute for the perfumes or added to them) function as particularly effective solvents for low-fat dirt on hard surfaces that are cleaned, and form the dispersed phases in oil-in-water (O/w) microemulsions. The cosurfactants and the polyvalent metal ions are also of functional importance, the former helping to stabilize the microemulsion and the latter helping to improve the detergency, especially for more dilute detergents, and when the polyvalent salts of the anionic used

surfactants are more effective than surfactants against the greasy dirt encountered during use.

Various perfumes which have been found to be useful in forming the dispersed phase in the °/v microemulsion detergents may be those normally used in cleaning products, and they are preferably normally present in liquid form. They include esters, ethers, aldehydes, alcohols and alkanes used in the perfume industry, but the essential oils that have a high terpene content are the most important. It seems that the terpenes (and terpineols) cooperate with the cleaning components in the microemulsions so that the cleaning power of the cleaning agents according to the invention is improved in addition to forming the stable dispersed phase in the microemulsions. It has been shown according to the present invention that especially when a pine-like perfume is used, the amount of a comparatively expensive such perfume can be reduced, and this can be compensated for with α-terpineol, and in some cases with other terpenes. For example, for every 1% perfume, 60 - 90% of this, e.g. about. 80%, is replaced with a-terpineol and while achieving essentially the same pine smell and with good cleaning and microemulsion stability. similarly, terpenes and other terpene-like compounds and derivatives may be used, but α-terpineol is considered the best.

The polyvalent metal ion present in the cleaning agents according to the invention may be any such ion, including magnesium (generally preferred), aluminium, copper, nickel, iron or calcium, and the ion or mixture thereof may be added in any preferably in a suitable form, and occasionally as an oxide or hydroxide, but usually in the form of a water-soluble salt. It appears that the polyvalent metal ion reacts with the anion in the anionic surfactant (or replaces the surfactant cation or produces an equivalent solution in the emulsion), improving the cleaning power and generally also improving other properties of the product. If the multivalent metal ion reacts with the surfactant anion to form an insoluble product, such a multivalent ion should be avoided. For example, calcium reacts with paraffin sulfonate anion to form an insoluble salt, and calcium ions, such as those obtainable from calcium chloride, will therefore be eluted from any emulsion cleaner of the invention containing paraffin sulfonate surfactant. In a similar way, the polyvalent ions or other components in the mixtures according to the invention and which will react unfavorably with other components will also be omitted. As previously mentioned, the polyvalent metal ion will preferably be magnesium, and this will be added to the other emulsion components in the form of a water-soluble salt. A preferred such salt is magnesium sulfate, usually used in the form of its heptahydrate (Epsom salts), but other hydrates of this or the anhydride can also be used. The sulfates of polyvalent metals will generally be used because their sulfate anions are also the anion for some of the anionic surfactants and occur in some such surfactants as a by-product from neutralization.

The cosurfactant component(s) in the microemulsion cleansers reduces the interfacial tension or surface tension between the lipophilic droplets and the continuous

_3

aqueous medium to a value often close to 10 dyne/cm, which results in spontaneous breakdowns of the dispersed phase globules until they become so small that they cannot be seen with the naked eye, forming a clear microemulsion. In such a microemulsion, the surface area of the dispersed phase increases greatly, and its dissolving power and grease-removing ability are also increased, so that the microemulsion becomes significantly more effective as a cleaning agent for removing greasy dirt than when the globules in the dispersed phase are of normal emulsion size. Among the co-surfactants that can be used in the cleaning agents according to the invention, mention can be made of water-soluble lower alkanols with 2-4 carbon atoms per molecule (occasionally preferably 3 or 4), polypropylene glycols with 2-18 propoxy units, monoalkyl lower glycol ethers of the formula RO(X)nH, where R is C 1 -alkyl, X is CH 2 CH 2 O, CH 2 CH 2 CH 2 O or CH(CH ,)CH,0, and n is 1 - 4, monoalkyl esters of the formula R 1 0(X)nH, in which R 1 is C 2_4 acyl, and X and n are.-as described immediately above, aryl-substituted alkanols with 1- 4 carbon atoms, propylene carbonate, aliphatic mono-, di- and tricarboxylic acids with 3-6 carbon atoms, mono-, di- and trihydroxy-

substituted aliphatic mono-, di- and tricarboxylic acids of 3 - 6 carbon atoms, higher alkyl ether poly-lower alkoxy carboxylic acids, lower alkyl mono-, -di- and -triesters of phosphoric acid in which the lower alkyl group has 1-4 carbon atoms, and mixtures thereof.

Representatives of such cosurfactants are succinic, glutaric and adipic acids, diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether and diethylene glycol monoisobutyl ether, which are considered the most effective.

Based on the above description of applicable co-surfactants in the present cleaning agents, it appears that succinic, glutaric and adipic acids, and a mixture of such components, are useful for lowering the product's pH so that this easily removes soap scum and scale from surfaces that are to cleaned, and at the same time they function as co-surfactants while improving the appearance of the product and so that this becomes more effective in removing grease from such surfaces. Similar dual effects can be achieved by using other of the indicated acidic materials which are co-surfactant in the described cleaning agents.

Although it is strongly preferred that the present cleaning agent mixtures are in the form of aqueous microemulsions, according to the invention it is aimed that this should include less preferred emulsions (in which the globules in the dispersed phase have larger sizes), but in such cases the cleaning power of the product will be less because there will not be as good contact between the cleaning agent and the surface being treated. Although microemulsions are highly preferred embodiments of the invention, other emulsions and other forms of the mixture can also be used, such as gels, pastes, solutions, foams and aerosols, which include aqueous media.

In the cleaning agents according to the invention, it is important that the relative quantities of the components lie within certain areas so that the product will most effectively remove greasy dirt, lime scale and soap scum and other deposits from the hard surfaces that are subjected to treatment, and so that such surfaces are protected during a such treatment. As previously indicated, the surfactant should be present in a cleaning amount sufficient to remove greasy and oily soil, the amount or amounts of carboxylic acid or carboxylic acids should be sufficient to remove soap scum and scale, the phosphonic acid or the phosphoric and phosphonic acid mixture should be present in a sufficient amount to prevent the carboxylic acid or acids from damaging acid-sensitive surfaces, and the aqueous medium should be a solvent and suspending medium for the necessary components and for any excipients that may also be present. The percentages of the components are therefore 2-8% synthetic anionic organic surfactant or surfactants, 1-6% synthetic, organic nonionic surfactant or surfactants, 2-10% aliphatic carboxylic diacids, 0.05-1% phosphoric acid or monosalt thereof, and 0.01-0.2% aminoalkylenephosphonic acid or acids or monophosphonic salt or salts thereof, and the remainder water and auxiliary substance or substances if such are present. Among the carboxylic diacids, it is preferred that

a mixture of succinic, glutaric and adipic acids is used, and the ratio between these is most preferred within the range 1-3:6: 1-2, the ratios being 1:1:1 or approx. 2:5:1 are the most preferred. The ratios of aminoalkylenephosphonic acid to phosphoric acid to aliphatic carboxylic diacids are usually approx. 1:1-20:20-500, preferably 1:2-10:10-200, and more preferably approx. 1:4:25, 1:7:170 and 1:3:25 in three representative recipes. However, ranges as wide as 1:1-2000:10-4000 can be used, and the preferred range for the ratio of dicarboxylic acid to phosphonic acid is sometimes 5:1-250:1. In a similar way, a mixture of succinic, glutaric and adipic acids can have the ratio Q .8-4:0.8-10:1, and the ratio between dicarboxylic acid and phosphoric acid can be from 5:2 to 25:1.

As a rule, 0.05 - 5%, preferably 0.1 - 0.3%, multivalent ion, preferably magnesium or aluminium, and more preferably magnesium, will be present in the cleaning agent, especially when the paraffin sulphonate is the surfactant. The percentage of perfume is also normally within the range 0.2 - 2%, preferably 0.5 - 1.5%, and of this perfume at least 0.1% is terpene or terpineol. The terpineol is a-terpineol and is preferably added to enable a reduction in the amount of perfume, as the total amount of perfume (including the a-terpineol) is made up of

50 - 90% terpineol, preferably approx. 80% of this.

For preferred formulations of the present cleansers which differ in that one contains two anionic surfactants and the other only one, the latter will contain 3-5% sodium paraffin sulfonate, wherein the paraffin has ^^. A- IT

2 - 4% non-ionic surfactant which is a condensation product of a fatty alcohol having 9 - 15 carbon atoms, with 3-15 mol of ethylene oxide per mole higher fatty alcohol, 3 - 7% of a 1:1:1 or 2:5:1 mixture of succinic, glutaric and adipic acids, 0.1 -

0.3% phosphoric acid, 0.03 - 0.1% aminotrismethylenephosphonic acid,

0.1 - 0.2% magnesium ion, 0.5 - 2% perfume of which 50 -

90% consists of a-terpineol, 0 - 5% excipients and 75 -

90% water. Such a cleaning agent will more preferably comprise or consist essentially of approx. 4% sodium paraffin ( ci4_ ij)~ sulphonate, approx. 3% of the non-ionic surfactant, approx. 5% of the 2:5:1 mixture of the dicarboxylic acids, approx. 0.2% phosphoric acid, approx. 0.05% aminotrismethylenephosphonic acid, approx. 1% perfume which includes approx. 0.8% α-terpineol, approx. 0.7% magnesium sulfate (anhydrous), approx. 3% excipients and approx. 83% water.

The second preferred formulation comprises 0.5 - 2% sodium paraffin sulfonate, wherein the paraffin has ci^^^ T 2 - 4% sodium ethoxylated-higher fatty alcohol sulfate, wherein the higher fatty alcohol has 10-14 carbon atoms and which contains 1-3 ethylene oxide groups per . mol, 2 - 4% non-ionic surfactant which is a condensation product of fatty alcohol having 9-15 carbon atoms, with 3-15 mol ethylene oxide per moles of fatty alcohol, 3 - 7% of a 1:1:1 mixture of succinic, glutaric and adipic acids, 0.1 0.3% phosphoric acid, 0.01 - 0.05% aminotrismethylenephosphonic acid, 0.09 - 0, 17% magnesium ion, 0.5 - 2% perfume of which at least 10% is terpene(s) and/or terpineol, 0 - 5% auxiliary substance(s) and 75 - 90% water. Such a cleaning agent, with two anionic surfactants, will more preferably include or essentially consist of approx. 1% sodium paraffin (C^_^)-sulfonate, approx. 3% sodium ethoxylated higher fatty alcohol sulphate, in which the higher fatty alcohol is lauryl alcohol and the degree of ethoxylation is 2 mol ethylene oxide per minor, approx. 3% non-ionic surfactant which is a condensation product of a Cp,_ii linear alcohol and 5 mol ethylene oxide, approx. 5% of a 1:1:1 mixture of succinic, glutaric and adipic acids, approx. 0.2% phosphoric acid, approx. 0.03% aminotrismethylenephosphonic acid, approx. 0.7% magnesium sulfate (anhydrous), approx. 2% excipients and approx. 84% water.

The pH of the various cleaning agents, preferably microemulsion cleaning agents, is 1-4, preferably 1.5-3.5, e.g. 3. The water content of the microemulsions will usually be within the range 75 - 90%, preferably 80 - 85%, and the excipient content will be 0 - 5%, as a rule 1 - 3%. If the pH is not within the desired range, it will usually be regulated with either sodium hydroxide or suitable acids, e.g. sulfuric acid solutions, but normally the pH will be raised and not lowered, and if it is to be lowered, more of the dicarboxylic acid mixture can be used instead.

The cleaning agents according to the invention, which are in microemulsion form, are clear o/w emulsions and exhibit stability at room temperature and at elevated and reduced temperatures, from 10 to 50° C. They are easily pourable and exhibit a viscosity within the range 2 - 150 or 200 centipoise, e.g. 5-40 cP, as desired, and the viscosity can be partly regulated by adding to the recipe a thickening agent, such as lower alkyl cellulose, e.g. methylcellulose or hydroxypropylmethylcellulose, or a water-soluble resin, e.g. polyacrylamide, or polyvinyl alcohol. Any tendency that the product may have to foam in an undesirable way can be counteracted by incorporating free fatty acid or soap into the recipe

in smaller quantities, which is known in detergent technology (at low pH, the soap turns to acid).

The liquid cleaning agents can be prepared simply by mixing the various components for them, and the order of addition is not of critical importance. In order to mix the different water-soluble components with each other, it is however desirable that the oil-soluble components are mixed together in a separate operation, and that the two mixtures are mixed with each other as the oil-soluble part is added to the water-soluble part (in the water) with stirring or other agitation . In some cases, such a method can be varied to prevent any unwanted reactions between components. For example, concentrated phosphoric acid will be added directly to magnesium sulfate or to a dye, but such additions will be in the form of aqueous solutions, preferably diluted, of the components.

The cleaning agent can be packaged in the desired manner in manually operated shower-dispensing containers which are usually and preferably made of synthetic, organic, polymeric plastic material, such as polyethylene, polypropylene or polyvinyl chloride (PVC). Such containers also preferably include a closure device, shower nozzle, immersion tube and associated dispensers of nylon or other non-reactive plastic, and the resulting packaged cleaner is ideally suited for use in "shower and wipe" applications. However, in some cases, such as when scale and soap scum deposits are strong, the cleaner can be left on until it has dissolved or loosened the deposits, and it can then be wiped or rinsed away, or several applications can be made, followed by several removals, until the deposits are gone. For shower applications, the viscosity of the microemulsion (or of a normal emulsion if one is used instead) will preferably be increased so that the liquid will stick to the surface as must be cleaned, which is particularly important when such a surface is vertical, to prevent immediate run-off of the cleaning agent and consequent reduced efficiency. Occasionally the product may be formulated as an "aerosol shower type" so that its foam discharged from the aerosol container will adhere to the surface to be cleaned. At other times, the aqueous medium may be such that a gel or paste is obtained which is deposited on the surface by application by hand, preferably with a sponge or cloth, and which is removed by a combination of rinsing and wiping, preferably with a sponge, after which it can be left to dry so that it becomes shiny or it can be wiped with a cloth. If this were to be practical, the cleaned surface can of course be rinsed to remove all traces of acid from it.

The examples below illustrate

the invention. All parts, amounts and percentages in the examples, description and claims are based on weight, and all temperatures are in °C unless otherwise stated.

Example 1

The microemulsion cleaner is prepared by dissolving the surfactants in the water, after which the rest of the water-soluble materials are added to the surfactant solution, with stirring, except for the perfume and the pH-adjusting agent (sodium oxide solution). The pH is adjusted to 3.0, and then the perfume is stirred into the aqueous solution, instantly forming the desired microemulsion which has a clear blue color and a viscosity within the range of 2-20 cP. If the viscosity is lower or if it is considered desirable that this be increased, 0.1 - 1% of a suitable rubber or resin can be incorporated into the recipe, e.g. sodium carboxymethylcellulose or hydroxypropylmethylcellulose, or polyacrylamide or polyvinyl alcohol or a suitable mixture thereof.

The acidic cleaning agent is packaged in squeezable polyethylene bottles fitted with polypropylene shower nozzles that can be adjusted to closed, shower-emitting and current-emitting positions. During use, the microemulsion is sprayed onto the "bathtub"

on a bathtub that also exhibits lime scale in addition to soap scum and greasy dirt. The amount of application is approx. 5 ml per 5 m ring (which is approx. 3 cm wide). After application and after waiting for approx. After 2 minutes, the ring is wiped away with a sponge and is removed with water using a sponge. It turns out that the greasy dirt, soap scum and even limescale have been effectively removed. In such cases where the lime scale is particularly thick or adherent, another application may be desirable, but this is not considered to be the norm.

The tub surface can be rinsed because it is so easy to rinse a bathtub (or a shower), but such a rinse is not necessary. Occasionally, dry wiping will be sufficient, but if it is desired to remove any acid residue, the surface can be treated with water and a sponge or wiped with a damp cloth, but in such a case it is not necessary to apply more than 10 times the applied weight of detergent.

In other words, there is no need to carefully shower or rinse the surface with water, and it will still be clean and shiny (assuming it was originally shiny). For other uses of the cleaner, this can be used to clean shower tiles, floor tiles in bathrooms, kitchen tiles, sinks and enamel objects in general without damaging their surfaces. It is recognized that several such surfaces are acid resistant, but a commercial product must be able to be used without damage to even less resistant surfaces, such as white European enamel (often on a cast iron or plate steel substrate) which is sometimes referred to as white zirconium powder enamel. It is a distinctive feature of the above-described cleaning agent (and other cleaning agents according to the invention) that they effectively clean hard surfaces, but they contain ionizable acids and should therefore not be applied to acid-sensitive surfaces. Nevertheless, they have been found not to damage white European enamel bathtubs, according to this example, which are seriously affected by cleaning with compositions exactly like the composition of this example, except that the phosphonic acid or phosphonic-phosphoric acid mixture has been omitted from these.

The main component according to the mixture that protects the European enamels is the phosphonic acid, and according to the recipe the amount of such acid has been reduced to below the minimum normally required at a pH of 3. Nevertheless, although 0.5% is normally the minimum amount when phosphoric acid is present, which is ineffective as such at such a pH, this increases the action of the phosphonic acid and enables a reduction in the amount of the more expensive phosphonic acid.

For variants of the recipe described, the same components are retained for all concerned and in the same quantities, except for the water and phosphonic and phosphoric acids. In experiments, 0.05% aminotris-methylenephosphonic acid was used, and the phosphoric acid was omitted. In experiment lb, 0.5% ethylenediaminetetramethylenephosphonic acid and no phosphoric acid are used, in experiment le 0.5% hexamethylenediaminetetramethylenephosphonic acid and no phosphoric acid are used, in experiment ld 0.4% diethylenetriaminepentamethylenephosphonic acid and no phosphoric acid are used, and in experiment le 0.1% diethylenetriaminepentamethylenephosphonic acid is used and 0.6% phosphoric acid. The cleaning power of the mixtures 1d and 1e is approximately the same, and this shows that the presence of the phosphoric acid, which is essentially inactive as a protector of surfaces against the effects of the carboxylic acids present in the mixture, reduces the amount of phosphonic acid used to protect the surfaces , to 1/4 of the amount previously required. Similar effects can be achieved when phosphonic acid is used in the mixtures lb and lc in approximately the same quantities as in example 1 and example le.

If very strong foaming occurs when the cleaning agent is used, an anti-foaming agent, such as a silicone or coconut fatty acid, can be added. Alternatively, coconut diethanolamine can be added to increase foaming.

Example 2

The mixtures according to this example are prepared in the same way as the mixtures according to example 1 and they are also tested in the same way with similarly good results. The microemulsions have a clear lighter blue color and their pH is adjusted to 3.0. The cleaners easily remove soap scum and greasy dirt from hard surfaces and loosen and facilitate the removal also of scale with minimal rinsing or sponging, as reported in Example 1. The presence of the aminotrismethylenephosphonic acid prevents damage to the acid-sensitive surfaces due to the carboxylic acids, and the presence of the phosphoric acid enables reduction of the amount of aminotrismethylenephosphonic acid used. For example, according to example 2a, without phosphoric acid present, 0.1% of the aminotrismethylenephosphonic acid is required to prevent damage to European enamel when using the cleaning mixture. Similarly, according to Example 1b where the recipe is the same, except that the phosphonic and phosphoric acids are replaced by 0.2% phosphonic acid (diethylenetriaminepentamethylenephosphonic acid) and 0.6% phosphoric acid, European enamel remains undamaged, while to achieve the same desired effect without the phosphoric acid being present, 0.5% of the phosphonic acid is required. Similar results are obtained when the 0.5% of the phosphonic acid is replaced by the same amount of ethylenediaminetetramethylenephosphonic acid or hexamethylenediaminetetramethylenephosphonic acid, with and without supplemental phosphoric acid.

It thus appears from this example (and example 1) that phosphoric acid, which is essentially ineffective in protecting acid-sensitive surfaces against the effects of carboxylic acids in the present cleaning agents, improves the protective effects of phosphonic acids and does this to a significant extent for bathtub European enamel.

Example 3

The above mixture is prepared in the manner previously described, and is similarly tested and found to be satisfactory for cleaning acid-sensitive objects with hard surfaces, such as bathtubs and sinks of cast iron or plate steel coated with European enamel, for greasy dirt on these and to facilitate the removal of soap scum and scale from such surfaces. When the phosphonic and phosphoric acids are omitted from the recipe or when only the phosphonic acid is omitted, the cleaning agent attacks such surfaces and dissolves them. The presence of the phosphoric acid makes it possible to reduce the amount of phosphonic acid that is necessary to inhibit the cleaning agent so that it will not attack the European enamels, and this reduction is significant, especially for economic reasons, but also functionally, the a-terpineol replaces part of the perfume and helps with the formation of the microemulsion while not destroying the pleasant smell that the perfume imparts to the product,

and such results can be achieved with other perfumes of the pine type. The a-terpineol facilitates, in a similar way to the terpene components of a pine-type perfume, the formation of the microemulsion, but the terpineol is even more active because it is an essentially 100% terpene-type compound, whereas perfumes are usually less than 50% of terpenes.

Example 4

When variations of the above-mentioned recipes are made by substituting different anionic and non-ionic surfactants, of the types described here, by using other polyvalent salts (or omitting these), by using other phosphonic acids, with or without phosphoric acid, and by varying the amount of components by + 10%, 30% and 30%, within the ranges indicated in the present description, usable microemulsion cleaners can be obtained which will satisfactorily clean hard surfaces and remove soap scum and scale from them without damaging them , even if they consist of European enamel.

The cleaning agents are preferably available as microemulsions, but even if the microemulsion were to be "broken down" to a regular emulsion, the product would be able to be used as an effective cleaning agent, and such emulsions are therefore also 1 within the scope of the invention. It may be preferred to dispense the cleaning agent from a shower bottle, but it can also be packaged in ordinary bottles. It can be produced in the form of a paste or gel so that it will stick better to surfaces on which it is applied, so that it will stay on the dilsse and work so that it attacks the lime scale instead of running down and away from the surface. Although mixtures have also been mentioned in the present description, even where they have not been specifically referred to, it should be understood that mention of a single component includes reference to mixtures of such components in the present cleaning agents.

Claims (9)

1. Acidic, aqueous cleaner for bathtubs and other objects with hard surfaces that are resistant to acids or are of zirconium white enamel, the cleaner having a pH of 1-4 and removing scale, soap scum and greasy dirt from the surfaces of such objects without damaging such surfaces, characterized in that it comprises 2-8% of a synthetic organic anionic surfactant or surfactants selected from the group consisting of water-soluble salts of lipophilic sulfonic and sulfuric acids, 1-6% of a synthetic organic non-ionic surfactant or surfactants selected from the group consisting of condensation cation products of ethylene oxide or ethylene glycol with a lipophilic part that is a higher alcohol, phenol, propylene oxide polymer or propylene glycol polymer, 2-10% of an aliphatic carboxylic diacid or diacids with 4-7 carbon atoms, 0.05-1% phosphoric acid and 0.01- 0.2% of an aminoalkylenephosphonic acid or acids of the formula wherein Y is alkylamino or N-substituted alkylamino, the aminoalkylenephosphonic acid containing 1-3 amino nitrogens, 3 or 4 lower alkylenephosphonic acid groups in which the lower alkylene has 1 or 2 carbon atoms, and 0-2 alkylene groups each with 2-6 carbon atoms, the alkylene group(s) ) are present and connect amino nitrogens when several such amino nitrogens are present in the aminoalkylenephosphonic acid. 2. Cleaning agent according to claim 1 in the form of a liquid emulsion, characterized in that the ratio between dicarboxylic acid and aminoalkylenephosphonic acid is within the range 5:1 - 250:1. 3. Cleaning agent according to claim 2, characterized in that the aminoalkylenephosphonic acid is selected from the group consisting of aminotrismethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid and mixtures thereof. 4. Cleaning agent according to claim 1 in the form of a liquid emulsion, characterized in that the amount of phosphoric acid is within the range 2:1 - 10:1 with respect to the aminoalkylenephosphonic acid and that the ratio between dicarboxylic acid and phosphoric acid is within the range 5:2-25:1. 5. Cleaning agent according to claim 1 in the form of a liquid emulsion, characterized in that the synthetic organic anionic surfactant is selected from the group consisting of water-soluble higher paraffin sulfonate and water-soluble ethoxylated higher fatty alcohol sulfate which has 1-10 ethylene oxide groups per mol, and mixtures thereof, that the non-ionic surfactant is a condensation product of a fatty alcohol having 9-15 carbon atoms, with 3-15 mol of lower alkylene oxide per mol higher fatty alcohol, that the diacid or diacids are a mixture of succinic, glutaric and adipic acids in the ratios 0.8 - 4:0.8 - 10:1, and that the aminoalkylenephosphonic acid is aminotrismethylenephosphonic acid. : 6. Detergent according to claim <5>, characterized in that it has a pH within the range 2.5 - 3.5 and comprises 3 - 5% sodium paraffin sulphonate in which the paraffin has C]_4_^7' 2 - 4% non-ionic surfactant which is a condensation product of a fatty alcohol which has 9 -15 carbon atoms, with 3-15 mol lower alkylene oxide per mol higher fatty alcohol, 3 - 7% of the mixture of succinic, glutaric and adipic acids, 0.1 - 0.3% phosphoric acid, 0.03 - 0.1% aminotrismethylenephosphonic acid, 0.1 - 0.2% magnesium ion, 0 .5 - 2% perfume, of which 50 - 90% is a-terpineol, 0 - 5% excipients and 75 - 90% water. 7. Cleaning agent according to claim 6, characterized by the fact that it includes approx. 4% sodium paraffin sulphonate, approx. 3% non-ionic surfactant, approx. 5% of an approx. 2:5:1 mixture of succinic, glutaric and adipic acids, approx. 0.2% phosphoric acid, approx. 0.05% aminotrismethylenephosphonic acid, approx. 1% perfume, approx. 0.7% anhydrous magnesium sulfate, approx. 1% excipients and approx. 81% water. 8 . Cleaning agent according to claim 5, characterized in that it comprises 0.5 - 2% sodium paraffin sulphonate in which the paraffin has ^^. A- IT 2 - 4% sodium ethoxylated higher fatty alcohol sulphate in which the higher fatty alcohol has 10 - 14 carbon atoms and which contains 1-3 ethylene oxide groups per mol, 2 - 4% non-ionic surfactant which is a condensation product of fatty alcohol having 9-15 carbon atoms, with 3-15 mol ethylene oxide per mol higher fatty alcohol, 3 - 7% of an approximately 1:1:1 mixture of succinic, glutaric and adipic acids, 0.1 - 0.3% phosphoric acid, 0.01 - 0.05% aminotrismethylenephosphonic acid, 0.09 - 0.17% magnesium ion, 0.5 - 2% perfume of which at least 10% is terpene or terpenes and/or terpineol, 0 - 5% excipient or excipients and 75 - 90% water. 9 . Cleaning agent according to claim 8, characterized in that it comprises approx. 1% sodium paraffin sulphonate, approx. 3% sodium-ethoxylated-higher-fatty alcohol sulphate, approx. 3% non-ionic surfactant, approx. 5% of a 1:1:1 mixture of succinic, glutaric and adipic acids, approx. 0.2% phosphoric acid, approx. 0.03% aminotrismethylenephosphonic acid, approx. 0.7% magnesium sulfate, approx. 1% perfume, approx. 1% excipients and approx. 85% water.