WO1996023052A1

WO1996023052A1 - Aqueous cleaning composition

Info

Publication number: WO1996023052A1
Application number: PCT/US1996/001133
Authority: WO
Inventors: Pierre Marie Lenoir
Original assignee: The Dow Chemical Company
Priority date: 1995-01-24
Filing date: 1996-01-23
Publication date: 1996-08-01
Also published as: AU4706396A; EP0724011A1

Abstract

An aqueous cleaning composition comprises a bleach, a surfactant, and an alkylene glycol diether of formula (I): R1O-(CH2-CHR3O)n-R2, wherein the substituents R?1 and R2¿ each independently are alkyl, cycloalkyl, alkenyl or aryl, R3 in each occurrence independently is methyl or ethyl, and n is from 1 to 30. The cleaning composition has a good cleaning capability and a good storage stability.

Description

AQUEOUS CLEANING COMPOSITION

The present invention relates to an aqueous cleaning composition which comprises a bleach and a surfactant. Furthermore, the present invention relates to a process for preparing the aqueous cleaning composition and to the use of the aqueous cleaning composition for cleaning, particularly for cleaning hard surfaces, such as glass, metallic and polymeric surfaces.

Cleaning compositions which comprise a bleach and a surfactant are known in the art. U.S. Patent 4,057,505 discloses a liquid cleaning and bleaching composition which essentially consists of an aqueous solution of from 3 to 7 percent by weight of an alkali metal hypochlorite and from 0.5 to 8 percent by weight of a synthetic alcohol sulfate as a surfactant, with the balance essentially being water. The cleaning composition is recommended for cleaning and bleaching textiles. U.S. Patent 5,164,106 discloses a nonaqueous liquid automatic dishwasher detergent composition containing a dual bleach system. The composition contains a nonaqueous organic carrier liquid, a chlorine bleach source, a bromide compound and a surfactant. The detergent composition is said to be stable in storage and readily dispersible in water. U.S. Patent 4,071,463 discloses an aqueous cleaning formulation which is useful for removal of stubborn stains, such as fruit juices, tea, coffee and ink, from counter tops and like surfaces. The aqueous cleaning formulation contains a synthetic detergent, sodium hypochlorite and a water-soluble alkaline builder to maintain the pH of the formulation above 10. The synthetic detergent is an alkali metal alkyl sulfate, an alkali metal salt of an alkylated diphenyl oxide sulfonic acid, a branched chain alkyl aryl sulphonate or a mixture thereof. The cleaning formulation may also contain thickening agents to enhance the stability of the cleaner on vertical surfaces. Furthermore, the cleaning formulation may contain minor amounts (for example, up to 1 weight percent of the formulation) of bleach stable organic solvents to enhance the cleaning effectiveness of the composition. Petroleum distillates, such as kerosene and naphtha, are typical of such useful solvents.

Published European Patent Application EP-A-0,336,651 discloses a thickened aqueous hard surface abrasive cleanser which has an improved cleaning efficacy due to the presence of an organic solvent in the composition. It is disclosed that the organic solvent can be included in the cleanser without causing the system to become unstable. The cleanser comprises from 5 to 70 percent by weight of a particulate abrasive, an anionic, nonionic, amphoteric or zwitterionic surfactant, from 0.1 to 10 percent by weight of an electrolyte buffer, from 1 to 15 percent by weight of a colloidal alumina thickener, up to 5 percent by weight of a fatty acid soap and up to 10 percent by weight of an organic solvent. The cleanser may comprise a bleach, preferably sodium hypochlorite, in an amount of from 0.1 to 5 percent. The water content of the cleanser preferably is from 10 to 80 percent by weight.

Derwent Abstract WPI 88-025265/04, abstracting JP-A-62286000, discloses a liquid detergent composition which contains 0.1 to 8 weight percent of a hypochlorite, 0.1 to 10 weight percent of an alkali agent, 0.1 to 8 weight percent of a surfactant stable to the hypochlorite and the agent, and 0.1 to 10 weight percent of a solvent of formula CH₃-0-(EO)_n(PO)_m-CH₃, wherein EO is -CH₂-CH₂-0; PO is CH(CH₃)-CH₂-0-, n is from 1 to 455 and m is from 0 to 5, with n + m being at least 1. The hypochlorite is sodium or potassium hypochlorite or a mixture thereof. The alkali agent is sodium hydroxide or potassium hydroxide or a mixture thereof. In the formula, preferably n is from 1 to 15 and m = 0. Surfactants include polyoxyethylene, alkyl phenyl ether sulfates, alkyl diphenyl ether disulfonates and alkyl sulphates.

Although various aqueous cleaning compositions are known which contain a bleach and a surfactant, there is still the need to provide new cleaning compositions which have a high cleaning capability. Furthermore, there is a high demand for cleaning compositions which can be transported and stored as concentrates and which can be diluted with water prior to usage, for example, by the end-users. Transportation and storage of concentrated cleaning compositions is highly desirable for ecological and economic reasons because it reduces the energy and costs which are required for packaging, transporting and storing the cleaning compositions over an extended period of time. However, storage of concentrated cleaning compositions requires that even the concentrates are stable over an extended period of time. Accordingly, one object of the present invention is to provide a new cleaning composition. A preferred object of the present invention is to provide a new cleaning composition which exhibits a high cleaning capability and a sufficient storage stability, even when the cleaning composition is stored as a concentrate.

Surprisingly, it has been found that the cleaning capability of an aqueous cleaning composition comprising a bleach and a surfactant can be significantly increased by including certain alkylene glycol diethers in the cleaning composition. It has been found that this increased cleaning capability is even observed in diluted cleaning compositions wherein the concentration of this alkylene glycol diether is less than 0.5 weight percent, typically even less than 0.1 weight percent. Even more surprisingly, it has been found that the inclusion of such an alkylene glycol diether does not reduce the storage stability of the cleaning composition in an unacceptable degree.

Accordingly, one aspect of the present invention is an aqueous cleaning composition which comprises a bleach, a surfactant, and an alkylene glycol diether of formula I RiO - (CH₂ - CHR30)_n - R2 (I), wherein the substituents R¹ and R² each independently are alkyl, cycloalkyl, alkenyl or aryl, R³ in each occurrence independently is methyl or ethyl, and n is from 1 to 30.

Another aspect of the present invention is a process for preparing this cleaning composition by blending one or more of the bleaches, one or more of the surfactants, one or more of the alkylene glycol diethers of formula I, water and optional additives. Yet another aspect of the present invention is the use of the cleaning composition for cleaning, particularly for cleaning hard surfaces. The cleaning composition can be used as household cleaner or for commercial purposes.

An essential component of the cleaning composition of the present invention is the alkylene glycol diether of formula I. RlO - (CH₂ - CHR30)_n - R2 (I)

In formula I, the substituents R¹ and R² independently from each other represent alkyl, cycloalkyl, alkenyl, or aryl.

The alkyl groups are preferred over the cycloalkyl, alkenyl and aryl groups. Of the alkyl groups those are preferred that contain from 1 to 12, preferably from 1 to 6, most preferably from 1 to 4 carbon atoms. The alkyl groups can be straight-chain or branched. The more preferred alkyl groups are methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl or tert- butyl. Most preferably, both groups R¹ and R² are methyl.

Of the cycloalkyl groups, those containing 5 or 6 carbon atoms are preferred.

Of the alkenyl groups, those are preferred that contain from 2 to 12, preferably from 2 to 6, most preferably from 2 to 4 carbon atoms.

Of the aryl groups, those containing from 6 to 14 carbon atoms are preferred, such as benzyl, phenylbutyl, tolyl, xylyl, naphthyl, or, preferably, phenyl.

R³ in each occurrence independently is methyl or ethyl. Preferably, at least one substituent R³ is methyl. If the alkylene glycol diether contains propylene oxide units and butylene oxide units, these units can be distributed randomly or in blocks. Most preferably, each group R³ represents methyl.

In formula I, n is from 1 to 30, preferably from 1 to 12, more preferably from 1 to 6, most preferably 1, 2 or 3.

Preferred alkylene glycol diethers of formula I are propylene glycol dimethyl ether, propylene glycol methyl n-butyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol methyl n- butyl ether, butylene glycol dimethyl ether, and dibutylene glycol dimethyl ether. Propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and butylene glycol dimethyl ether are the most preferred alkylene glycol diethers. The alkylene glycol diethers of formula I and methods of preparing them are well known in the art. It has been found that the alkylene glycol diethers of formula I are surprisingly stable in the presence of the bleaches described below. The cleaning composition of the present invention may comprise one or more alkylene glycol diethers of formula I. Furthermore, the cleaning composition of the present invention comprises one or more bleaches. Bleaches are known in the art. Bleaches are, for example, peroxygen compounds, such as perborates, persulfates, perdisulfates, perphosphates, peroxocarboxylic acids or percarbonates. The sodium and potassium salts of the peroxygen compounds are preferred.

Preferred bleaches are hypohalites or hypohalite liberating compounds, more preferably hypochlorites or hypochlorite liberating compounds. Hypochlorite liberating compounds preferably are water-soluble, dry, solid materials which generate hypochlorite ions on contact with water. Examples thereof are sodium, potassium, lithium and calcium hypochlorite, chlorinated trisodium phosphate dodecahydrate, sodium and potassium tri- and dichloroisocyanurate, tri- and dichloroisocyanuric acid, dichlorodimethyl hydantoin, chlorobromo dimethyl hydantoin, N-chlorosulfamide, and chloramine. Preferred bleaching agents are alkali metal hypochlorites, most preferably sodium hypochlorite. Other useful hypochlorite generating compounds are those listed in U.S. Patent 5,164,106, column 7, lines 21-62.

Furthermore, the cleaning composition of the present invention comprises one or more surfactants. The surfactant should be stable in the aqueous cleaning composition in the presence of the bleach. Useful surfactants are described in U.S. Patent 5,164,106, column 5, line 61, to column 7, line 19, and European Patent Application 0,336,651, page 5, line 16, to page 6, line 14.

The cleaning composition of the present invention generally contains an anionic, non-ionic, amphoteric or zwitterionic surfactant or a combination of two or more surfactants. Preferably, an anionic surfactant is used, optionally in combination with a non-ionic surfactant, which is preferably bleach-stable. The most preferred surfactants are linear or branched mono- or dialkyl diphenyl oxide disulfonates. Preferred alkyl groups contain 8 to 18 carbon atoms. The alkali metal salts are preferred, particularly the sodium and potassium salts. Alkylated diphenyl oxide disulfonates are commercially available from The Dow Chemical Company as DOWFAX'" 3B2, DOWFAX'" 8390 and DOWFAX™ 2A1. Other useful anionic surfactants are the linear or branched mono- or dialkyl diphenyl oxide monosulfonates, primary and secondary alkyl sulphonates, alkyl sulphonates, alkyl benzene sulphonates and alkylaryl-sulphates wherein the alkyl groups preferably contain 8 to 18 carbon atoms. The alkali metal salts, particularly the sodium or potassium salts are preferred.

When a non-ionic surfactant is present in the cleaning composition of the present invention, it is preferably saturated. Useful nonionic surfactants are amine oxides, preferably trialkyl amine oxides. Preferred trialkyl amine oxides are (C₁.3-alkyl)₂Cio-20-^a"⁽yl-amine oxide, particularly dimethyldodecylamine oxide. Other useful non-ionic surfactants are poly-lower ether-capped alkoxylated higher alkanols wherein the alkanol contains 9 to 18, preferably 9 to 11 or 12 to 15 carbon atoms, the lower alkylene oxide contains 2 or 3 carbon atoms and the number of mols of lower alkylene oxide is from 3 to 12, preferably from 5 to 9. A preferred example is a surfactant wherein the alkanol is a fatty alcohol containing 12 to 15 carbon atoms and which contains about 7 ethylene oxide groups per mol. Useful amphoteric surfactants are betaines, imidazolines and quaternary phosphonium and tertiary sulfonium compounds.

Useful surfactants are described in European Patent Application 0,336,651 , page 5, line 16, to page 6, line 8, and in U.S. Patent 5,164,106, column 6, lines 12-56.

The cleaning composition of the present invention generally comprises from 0.01 to 30 percent, preferably from 0.02 to 15 percent, of the bleach, from 0.01 to 30 percent, preferably from 0.03 to 25 percent, of the surfactant, from 0.01 to 30 percent, preferably from 0.02 to 25 percent, of the alkylene glycol diether of formula I and from 10 to 99.97 percent, preferably from 35 to 99.93 percent of water, based on the total weight of bleach, surfactant, alkylene glycol diether and water. It is to be understood that the cleaning composition may comprise more than one bleach, more than one surfactant and/or more than one alkylene glycol diether of formula I. If the cleaning composition comprises more than one bleach, surfactant and/or alkylene glycol diether of formula I, their total amount is generally within the weight ranges indicated above.

The cleaning composition of the present invention may contain optional additives, such as alkaline builders and thickeners. The presence of a water-soluble alkaline builder may increase the stability of the bleach in the aqueous cleaning composition. Preferred alkaline builders are alkali metal carbonates, phosphates, polyphosphates, pyrophosphates, triphosphates, tetrapyrophosphates, metasilicates, polysilicates, chlorides, sulfates and silicates, of which the sodium salts are preferred. Any suitable base, such as sodium and potassium hydroxide, may also be employed. Preferably, the pH of the cleaning composition is above 7, more preferably above 8 or 9, most preferably from 10 to 13, if maximum stability of the bleach is to be attained. Other useful builders are zeolites, borates, aluminates and bleach-stable organic materials, such as gluconates, succinates, maleates and their alkali metal salts. Combinations of two or more alkaline builders may be used. Furthermore, one or more thickening agents, preferably one or more inorganic thickening agents, may be included in the cleaning composition of the present invention to enhance the stability of the cleaning composition on vertical surfaces. Preferred inorganic thickening agents are inorganic clays, such as Macoloid'" clay or a synthetic clay containing hydrated sodium magnesium silicates. Inorganic thickening agents are known in the art and are described, for example, in U.S. Patent 5,164,106. Other optional components of the cleaning composition are fatty acid salts, such as sodium or potassium, laurate, stearate or oleate; or non-oxygenated solvents, such as saturated hydrocarbons. The cleaning composition of the present invention may contain other optional additives, such as preservatives, bactericides, perfumes and/or coloring agents. Such optional additives and their useful amounts are known in the art.

The cleaning composition of the present invention is usually prepared by mixing the various ingredients. Typically, the ingredients are mixed at room temperature. To save transportation costs and energy, it is often preferred to prepare a concentrated aqueous composition and to dilute the concentrate with water prior to its use. For preparing the concentrate, deionized or tap water (hard water) can be used. Deionized water can be used for diluting the concentrate, however, tap water is also useful. o A concentrated aqueous composition generally comprises from 1 to 30 percent, more preferably from 2 to 15 percent, most preferably from 3 to 12 percent of the bleach, generally from 1 to 30 percent, preferably from 2 to 25 percent, more preferably from 5 to 20 percent of the surfactant, generally from 1 to 30 percent, preferably from 2 to 25 percent, more preferably from 3 to 20 percent of the alkylene glycol diether of formula I and from 97 to 5 10 percent, preferably from 93 to 35 percent, more preferably from 89 to 48 percent of water, based on the total weight of bleach, surfactant, alkylene glycol diether and water. If the concentrated aqueous composition comprises an alkaline builder, its concentration generally is from 0.5 to 30 percent, preferably from 1 to 25 percent, more preferably from 2 to 20 percent, based on the total weight of bleach, surfactant, alkylene glycol diether and water. If the 0 concentrated aqueous composition comprises a thickener, its concentration preferably is from 0.1 to 10 percent, more preferably from 1 to 5 percent, based on the total weight of bleach, surfactant, alkylene glycol diether and water. The concentrate can be used without previous dilution for removing stubborn stains, for example, for removing blood, fruit juices, tea, wine, coffee and greases from hard surfaces. The concentrate can also be used for killing germs on 5 hard surfaces.

The concentrate can be diluted with water for producing a household cleaning composition or an industrial cleaning composition which is ready for use. Preferred dilution ratios are from 5 to 1000, more preferably from 20 to 500, most preferably from 30 to 200 weight parts of water per weight part of concentrate. Alternatively, the components of the 0 aqueous cleaning composition can be mixed in such ratios that the prepared composition is ready for use. Such aqueous cleaning composition generally comprises from 0.01 to 0.8 percent, more preferably from 0.02 to 0.6 percent, most preferably from 0.03 to 0.5 percent of the bleach, generally from 0.01 to 0.8 percent, preferably from 0.03 to 0.6 percent, more preferably from 0.05 to 0.4 percent of the surfactant, generally from 0.01 to 0.8 percent, 5 preferably from 0.02 to 0.6 percent, more preferably from 0.03 to 0.5 percent of the alkylene glycol diether of formula I and from 99.97 to 97.6 percent, preferably from 99.93 to 98.2 percent, more preferably from 99.89 to 98.6 percent of water, based on the total weight of bleach, surfactant, alkylene glycol diether and water. If such aqueous cleaning composition comprises an alkaline builder, its concentration is preferably chosen such that the pH of the diluted composition is above 7, more preferably from 8 to 13.

The cleaning composition of the present invention is very useful for removing polar and non-polar impurities, such as grease, oils or salts, from hard surfaces, such as glass, ceramic, metallic or polymeric surfaces, or for killing germs on hard surfaces. The cleaning composition is particularly useful for removing impurities from floors, windows, tiles and counter tops. As indicated above, the cleaning capability of the composition of the present invention is significantly better than the cleaning capability of a comparable composition which does not contain an alkylene glycol diether of formula I. This increased cleaning capability is even observed in diluted cleaning compositions wherein the concentration of the alkylene glycol diether of formula I is less than 0.5 weight percent, typically even less than 0.1 weight percent. In many cases, this increased cleaning capability is even observed when the concentration of the alkylene glycol diether of formula I is less than 0.05 weight percent. Even more surprisingly, it has been found that the inclusion of the alkylene glycol diether of formula I does not reduce the storage stability of the cleaning composition in an unacceptable degree. Furthermore, the cleaning composition of the present invention evaporates fast, which is highly desirable when cleaning hard surfaces.

The cleaning composition can be applied to the surface to be cleaned in any known manner. For example, the cleaning composition may be applied to and/or distributed on the surface to be cleaned with a spraying device or an absorbent object, such as a sponge, cloth, paper, or piece of leather. Although the cleaning composition may be used at decreased or slightly elevated temperatures, it is preferably used at room temperature for cleaning purposes. The cleaning composition is preferably distributed on and/or at least partially removed from the surface by wiping with an absorbent object. Preferably, the bleach(es), surfactant(s), alkylene glycol diether(s) of formula I, water and optional alkaline builder(s) amount to 90 percent or more, more preferably 95 percent or more, and most preferably 99 percent or more of the total weight of the aqueous cleaning composition. Most preferably, the aqueous cleaning composition of the present invention essentially consists of the bleach(es), surfactant(s), alkylene glycol diether(s) of formula I, water and, optionally, alkaline builder(s).

The aqueous cleaning composition of the present invention is liquid at room temperature. It is usually prepared by mixing the various components of the composition in a known manner. The mixing temperature is not critical. Room temperature is the most convenient,however, decreased or elevated temperatures are also useful. The present invention is further illustrated by the following examples which should not be construed to limit the scope of the present invention. Unless otherwise mentioned, all parts and percentages are by weight. The cleaning capability of the aqueous cleaning composition is measured according to the IPP test, as published in Seifen, Oele, Fette, Wachse, Heft, 10/1986, pages 371-372, "Qualitatsnormen fϋr Fussbodenpflege- und Reinigungsmittel". A white carrier is treated with defined impurities. The contaminated carrier is wiped with a sponge which has been soaked with the cleaning composition under well-defined conditions. The cleaning effect is measured by comparing the reflection of the contaminated carrier after cleaning ("sample") in comparison with the reflection of a white carrier which has not been treated with impurities. The percentage of cleaning is calculated according to the following formula: (ref I. of sample - ref I. of impurities)* 100

% cleaned = -

(ref I. of white carrier - ref I. of impurities) The higher the number that is achieved by a specific cleaning composition in the IPP test, the better is its cleaning capability. The temperature and the humidity influence the cleaning capability of a given composition somewhat. Examples 1 to 4

A concentrated cleaning composition is produced by mixing 91 parts of an aqueous solution of sodium hypochlorite, 4 parts of an anionic surfactant, commercially available as DOWFAX" 3B2, and varying amounts of dipropylene glycol dimethyl ether. Varying amounts of water are added such that the total weight of the cleaning composition is 100 parts. The hypochlorite content in the aqueous solution of sodium hypochlorite is 6.05 percent. DOWFAX'" 3B2 surfactant contains 45 percent of the sodium salt of a C₁₀-alkylated diphenyl oxide disulfonate. Examples 5 to 8 The concentrated cleaning compositions of Examples 1 to 4 are diluted with tap water 65 times to produce diluted cleaning compositions which consist of 1.54 percent of the concentrated cleaning composition and 98.56 percent of tap water.

Table I (Temperature: 21°C, rel. humidity: 40%)

Weight Parts

Example Dipropylene Glycol % Cleaned

Dimethyl Ether

1 1 76

2 2 77

3 3 78

4 5 82

5 0.015 38

6 0.03 41

7 0.045 42

8 0.075 46

Example 9 and Comparative Examples A to D

A concentrated cleaning composition is produced by mixing 93 parts of an aqueous solution of sodium hypochlorite, 4 parts of an anionic surfactant, commercially available as DOWFAX'" 3B2, and 3 parts of either water (Comparative Example A) or an organic solvent (Comparative Examples B to D and Example 9). The surfactant and the sodium hypochlorite solution are the same as in Examples 1 to 4. The cleaning capability is measured shortly after preparation. The results are listed in Table II.

Table II

(Comparative ) 3 weight parts of .... (27°C, 56% Example rel. humidity)

% cleaned

A Water 73

B Ethylene glycol mono- 72 n-butyl ether

C Dipropylene glycol 84 monomethyl ether

D Dipropylene glycol 75 mono-n-butyT ether

9 Dipropylene glycol 86 dimethyl ether The comparison between Comparative Examples A, B, D and Example 9 shows that the inclusion of some glycol monoethers does not significantly increase the cleaning capability of the cleaning composition, as compared to the cleaning capability of a corresponding cleaning composition which does not contain an organic solvent (Comparative Example A). However, the inclusion of an alkylene glycol diether of formula I, specifically of dipropylene glycol dimethyl ether, in the cleaning composition significantly increases its cleaning capability. Comparative Example C (dipropylene glycol monomethyl ether) shows a good cleaning capability when the cleaning composition is fresh, however, its long-term stability is insufficient, as will be illustrated further below. Example 10 and Comparative Examples E to L

For determining the stability of the cleaning composition, a concentrated composition is produced by mixing 93 parts of an aqueous solution of sodium hypochlorite, 4 parts of an anionic surfactant, commercially available as DOWFAX'" 3B2, and 0, 1 or 3 parts of an organic solvent. The surfactant and the sodium hypochlorite solution are the same as in Examples 1 to 4. Varying amounts of water are added such that the total weight of the cleaning composition is 100 parts.

The concentration of the organic solvent is determined by gas chromatography after having stored the cleaning composition for 3 weeks at room temperature. The hypochlorite and chloride concentrations are measured shortly after the cleaning composition has been prepared and after having stored the cleaning composition for 1 and 2 weeks, respectively, at room temperature. The chloride concentration is determined using an SM-Titrino'" titrating agent. The hypochlorite concentration is determined by an iodometric method, as described in Praktikum der Massanalvse by W. Poethke, Verlag Harri Deutsch, 1980, page 178.

Table

(Compar¬ % OCI ative) Solvent % Example initial 1 week 2 weeks

Aqueous hypochlorite 6.1 6.4 6.3 solution

E 0 5.4 5.8 5.7 0 5.3 5.7 5.6

10 Dipropylene glycol 1 5.3 5.6 dimethyl ether 3 5.4 5.5 5.2

F Propylene glycol 1 5.9 5.2 monomethyl ether 3 5.6 3.7 1.0

G Dipropylene glycol 1 6.0 5.5 monomethyl ether 3 6.0 4.5 0.2

H Tripropylene glycol 1 5.1 5.6 monomethyl ether 3 5.2 4.8 3.9

I Propylene glycol 1 5.3 5.4 mono-n-butyl ether 3 5.2 3.6 0.9

J Dipropylene glycol 1 5.1 5.4 mono-n-butyl ether 3 5.2 4.1 0.1

K Tripropylene glycol 1 5.2 5.3 mono-n-butyl ether 3 4.7 2.8 0.1

L Ethylene glycol 1 6.0 5.8 mono-n-butyl ether 3 5.4 0.2

Table III (Continued)

(Com¬ % Chloride parative) Solvent % % Solv. Example (GC) initial 1 week 2 weeks 3 weeks

Aqueous 2.1 2.4 2.5 hypochlorite solution

E 0 2.2 2.2 2.4 0 2.1 2.3 2.3

10 Dipropylene glycol 1 2.2 2.3 1.0 dimethyl ether 3 2.2 2.3 2.5 2.8

F Propylene glycol 1 2.3 2.3 0.83 monomethyl ether 3 2.3 2.7 3.3 1.9

G Dipropylene glycol 1 2.2 2.3 0.73 monomethyl ether 3 2.2 2.5 3.4 1.7

H Tripropylene glycol 1 2.2 2.4 0.54 monomethyl ether 3 2.2 2.4 3.1 1.1

I Propylene glycol 1 2.2 2.4 0.66 mono-n-butyl ether 3 2.3 2.7 3.5 1.5

J Dipropylene glycol 1 2.2 2.4 0.58 mono-n-butyl ether 3 2.3 2.6 3.5 1.3

K Tripropylene glycol 1 2.2 2.4 0.40 mono-n-butyl ether 3 2.3 3.1 3.5 1.1

L Ethylene glycol 1 2.2 2.4 0.26 mono-n-butyl ether 3 2.3 3.5 1.5

The results in Table III illustrate that the inclusion of alkylene glycol monoethers in the cleaning formulation decreases the stability of the composition. Specifically, the hypochlorite content drastically decreases and the chloride content significantly increases within 2 weeks, and the solvent content significantly decreases within 3 weeks in Comparative Examples F to L. Surprisingly, this is not the case when an alkylene glycol diether of formula I, such as dipropylene glycol dimethyl ether, is included in the cleaning composition.

The results in Comparative Example E, according to which the hypochlorite concentration after 1 and 2 weeks is slightly higher than the initial hypochlorite concentration, and the corresponding results after 1 week in Example 10 are caused by a small systematic error in the measurements.

Examples 1 1 to 13 and Comparative Examples M to P

A concentrated cleaning composition is produced by mixing 91 parts of an aqueous solution of sodium hypochlorite, 4 parts of an anionic surfactant, commercially available as DOWFAX'" 3B2, and varying amounts of dipropylene glycol dimethyl ether or diethylene glycol dimethyl ether. Diethylene glycol dimethyl ether is among the preferred solvents in the liquid detergent composition disclosed in Derwent Abstract WPI 88-025265/04, abstracting JP-A-62286000. Varying amounts of water are added such that the total weight of the cleaning composition is 100 parts. The surfactant and the sodium hypochlorite solution are the same as in Examples 1 to 4.

Examples 14 to 16 and Comparative Examples Q to T

The concentrated cleaning compositions of Examples 11 to 13 and Comparative

Examples M to P are diluted with tap water 65 times to produce diluted cleaning compositions which consist of 1.54 percent of the concentrated cleaning composition and 98.56 percent of tap water.

Table IV (Temperature: 22°C, rel. humidity: 33%)

(Comparative ) Weight Parts Weight Parts Example Dipropylene glycol Diethylene glycol % Cleaned dimethyl ether dimethyl ether

M - - 78

11 1 - 79

12 3 - 80

13 5 - 81

N - 1 78

O - 3 79

P - 5 81

Q (diluted) - - 30

14 0.015 - 32

15 0.045 - 35

16 0.075 - 39

- 0.015 23

S - 0.045 26

T - 0.075 27 The results in Table IV illustrate that sufficient cleaning is achieved when an ethylene glycol diether is included in a concentrated cleaning composition instead of a propylene glycol diether. However, if the concentrate is diluted with tap water, as is normally the case for household cleaners, the presence of an ethylene glycol diether instead of a propylene glycol diether substantially decreases the cleaning capability of the composition. The diluted cleaners containing the ethylene glycol diether (Comparative Examples R to T) even have a lower cleaning capability than a corresponding diluted cleaner which does not contain a glycol diether (Comparative Example Q). Examples 17 to 22 and Comparative Examples U to X A concentrated cleaning composition is produced by mixing an aqueous solution of sodium hypochlorite, optionally an anionic surfactant, commercially available as DOWFAX'" 3B2, optionally sodium hydroxide and varying amounts of a glycol diether. Varying amounts of water are added such that the total weight of the cleaning composition is 100 parts. DOWFAX'" 3B2 surfactant contains 45 percent of the sodium salt of a Cio-alkylated diphenyl oxide disulfonate. The weight parts of the hypochlorite, surfactant, sodium hydroxide, glycol diether and water are listed in Table V below.

Table V

(Compara¬ tive ) Hypo¬ um Glycol Example chlorite Surfactant Sodi Hydroxide Diether* Water

17 5 2 1 1 91

18 5 2 1 2 90

19 5 2 1 3 89

20 5 2 2 3 88

U 5 1 - 94

V 5 - 95

W 5 2 1 - 92

21 5 1 2 92

22 5 2 1 1 91

X 5 2 1 1 91

* The glycol ether is dipropylene glycol dimethyl ether in Examples 17 to 21 , butylene glycol dimethyl ether in Example 22 and diethylene glycol dimethyl ether in Comparative Example X.

For determining the stability of the concentrated cleaning composition, the hypochlorite concentration is measured shortly after the cleaning composition has been prepared and after having stored the cleaning composition for 1 , 2, 3 and 4 weeks, respectively, in brown bottles at 35°C. The hypochlorite concentration is determined as in Example 10 and Comparative Examples E to L. The results are listed in Table VI below.

Table VI

(Com¬ % OCI ^■ parative) Example initial 1 week 2 weeks 3 weeks 4 weeks

17 5.0 4.88 4.85 4.77 4.50

18 5.0 4.94 4.88 4.78 4.58

19 5.0 4.95 4.86 4.78 4.62

20 5.0 4.97 4.86 4.74 4.62

U 5.0 4.97 4.89 4.79 4.66

V 5.0 4.90 4.90 4.74 4.60

W 5.0 4.81 4.79 4.64 4.46

21 5.0 4.98 4.96 4.82 4.68

22 5.0 4.89 4.79 4.73 4.45

X 5.0 4.82 4.74 4.53 4.34

The comparison between Examples 17, 18, 19 and 22 and Comparative Example W illustrates that the inclusion of an alkylene glycol diether of Formula I, such as dipropylene glycol dimethyl ether or butylene glycol dimethyl ether, does not further reduce the stability of the cleaning composition. This result is confirmed by comparing Example 21 and Comparative Example U. The stability of the compositions of Examples 17 to 19 is even better than the stability of the composition of Comparative Example W, which does not contain an alkylene glycol diether. Comparative Example X illustrates that the inclusion of diethylene glycol dimethyl ether in the cleaning composition has a negative impact on its stability.

Claims

WHAT IS CLAIMED IS:

1. An aqueous cleaning composition comprising a bleach, a surfactant, and an alkylene glycol diether of formula I RlO - (CH₂ - CHR30)_n - R² (I), wherein the substituents R¹ and R² each independently are alkyl, cycloalkyl, alkenyl or aryl, R³ in each occurrence independently is methyl or ethyl, and n is from 1 to 30.

2. The cleaning composition of Claim 1 wherein the substituents R¹ and R² in 0 formula I each independently are a C^^-alkyl group.

3. The cleaning composition of Claim 1 or Claim 2 wherein both substituents R¹ and R² in formula I are methyl.

4. The cleaning composition of any one of Claims 1 to 3 wherein n in formula I is from 1 to 6.

5. The cleaning composition of any one of Claims 1 to 4 wherein R³ in formula

I is methyl.

6. The cleaning composition of any one of Claims 1 to 5 wherein the bleach is a hypochlorite or a hypochlorite liberating compound.

7. The cleaning composition of any one of Claims 1 to 6 wherein the o surfactant is an anionic surfactant, optionally in combination with a non-ionic surfactant.

8. The cleaning composition of any one of Claims 1 to 7 comprising from 0.01 to 30 percent of the bleach, from 0.01 to 30 percent of the surfactant, from 0.01 to 30 percent of the alkylene glycol diether of formula I and from 10 to 99.97 percent of water, based on the total weight of bleach, surfactant, alkylene glycol diether and water.

9. A process for preparing the cleaning composition of any one of Claims 1 to

8 by blending one or more of the bleaches, one or more of the surfactants, one or more of the alkylene glycol diethers of formula I, water and optional additives.

10. Use of the cleaning composition of any one of Claims 1 to 8 for cleaning purposes. 0

5