Aqueous cleaning composition and its use in the cleaning of polymeric substrates

Abstract

An aqueous cleaning composition having utility in the processes by which footwear is manufactured, the composition comprising: water; phosphoric acid; at least one cationic surfactant; and, at least one water-miscible organic solvent, wherein the aqueous cleaning composition has a pH of from 1 to 5.

Description

[0001] Henkel AG & Co.KGaA

[0002] 2024P00373WO

[0003] AQUEOUS CLEANING COMPOSITION AND ITS USE IN THE CLEANING OF POLYMERIC SUBSTRATES FIELD OF THE INVENTION

[0004] The present disclosure is directed to an aqueous cleaning composition which may have utility in the cleaning of polymeric substrates. More particularly, the present disclosure is directed to an aqueous cleaning composition which comprises water, phosphoric acid, at least one cationic surfactant and a water-miscible organic solvent, which cleaning composition has particular utility in the removal of hydrophobic contaminants disposed on the surface of polymeric substrates.

[0005] BACKGROUND TO THE INVENTION

[0006] The manufacture of footwear typically includes a number of distinct phases. Firstly, in a design stage, a plan for the footwear is developed. Manufacturers then select materials based on the shoe design, and those materials are cut and bound together - through stitching or the use of adhesives - to form the main structure of the footwear. Workers then shape and fit the footwear to a mold - often referred to as a “last” - which provides the footwear with its final form. The footwear is then “finished’ by a treatment which often provides an aesthetic value through, for instance, painting, polishing and the addition of laces or other means of closure.

[0007] An illustrative shoe is provided in Figure 1 appended hereto. The depicted shoe (1) is broadly divided into an upper (2) and a sole (3). In the illustrated shoe, the upper (2) comprises a counter (21), a lining (22), vamps (23) and a toecap (24). The sole (3) herein is depicted as comprising a heel portion (31), an outsole (32), a midsole (33), an insole (34) and a bottom filler (35). These various components may be composed of several materials of which mention may be made of natural leather, synthetic leather, thermoplastic polyurethane (TPU), thermoplastic rubber (TPR), styrene -butadiene rubber (SBR), ethylene vinyl acetate (EVA) and polyvinyl chloride.

[0008] Where adhesives are to be used to bond together these various components, the process of bonding conventionally comprises the steps of: providing the material(s) to be bonded; surface treating the material(s); optionally applying a primer to at least one surface which is to be bonded; applying an adhesive composition to at least one surface which is to bonded; activating the adhesive composition; attaching and pressing the surfaces to be bonded; permitting the attached surfaces to stand or cool; and, testing of the obtained bond strength.

[0009] The aforementioned step of surface treatment is often important in ensuring the durability and quality of the bonded substrates. Physical surface treatments, chemical surface treatments and combinations thereof may be employed at this stage. Physical treatments of the surface are typically performed to increase the bonded surface area and, as such, may include the abrasion, roughening or feather edging of the surface. Abrasion and feather-edging may be effected using, for instance, an orbital sander having sandpaper of a pre-determined grit. After sanding, the treated area may optionally be cleaned again to remove any particulates generated during the abrasion operation or any other acquired dirt or contaminants.

[0010] Chemical treatments are known in the art and can be performed in a single or multi-stage manner constituted by, for instance, the use of one or more of: immersion in a cleaning solution; treatment with a cleaning solution; wiping the surface with a dry wipe; and, wiping the surface with a wet wipe which has been moistened with a cleaning solution.

[0011] Where the materials to be bonded are polymeric - and, in particular, where the polymeric surfaces to be bonded have low surface energy due to the presence of anti-adherend moieties on the surface - it has become conventional to use cleaning solutions which are wholly based on organic solvents. However, the use of organic solvents is deleterious to the environment and can furthermore be problematic in the manufacturing process. The organic solvents tend to be flammable, combustible and volatile and thus require careful handling, for which there is a concomitant practical cost.

[0012] Whilst it would be desirable to use cleaning compositions in which the amount of volatile organic compounds is reduced, there are practical impediments to doing so. Any cleaning composition should either pennit fast drying or should dry from the surface without the need to apply elevated temperatures. Moreover, the cleaning composition should provide similar surface wettability - or rather maintain an similar surface tension - to that of a cleaning composition based on organic solvents. And further, the cleaning composition should demonstrate similar cleansing properties across more than one substrate type such that, in the manufacture of footwear, it may pennit the cleaning composition to be used for more than one constituent. It would, for example, be deleterious if a cleaning composition having utility in the surface treatment of a midsole could not be utilized in the surface treatment of an outsole.

[0013] The present inventors have developed an aqueous cleaning composition which obviates the impediments to the use of compositions which are characterized by a reduced volatile organic compound (VOC) content relative to established cleaning compositions and which provide at least similar cleansing properties, especially for polymeric substrates conventionally used in the manufacturing of footwear, more specifically the assembly of shoe soles made from different polymeric substrates.

[0014] STATEMENT OF THE INVENTION

[0015] In accordance with a first aspect of the invention, there is provided an aqueous cleaning composition comprising: water; a) phosphoric acid; b) at least one cationic surfactant; and, c) at least one water-miscible organic solvent, wherein the aqueous cleaning composition has a pH of from 1 to 5.In certain embodiments, the aqueous cleaning composition comprises, based on the weight of the composition: from 10 to 60 wt.% of water; from 0.05 to 2 wt.% of a) said phosphoric acid; from 0.1 to 5 wt.% of b) said at least one cationic surfactant; and, from 20 to 90 wt.% of c) said at least one water-miscible solvent, wherein the aqueous cleaning composition has a pH of from 1 to 4.

[0016] In exemplary embodiments, the aqueous cleaning composition comprises, based on the weight of the composition: from 10 to 50 wt.%, preferably from 20 to 50 wt.% of water; from 0.05 to 1 wt.%, preferably from 0.1 to 1 wt.% of a) said phosphoric acid; from 0.1 to 1 wt.%, preferably from 0.1 to 0.5 wt.% of b) said at least one cationic surfactant; and, from 40 to 80 wt.%, preferably from 50 to 80 wt.% of c) said at least one water-miscible solvent, wherein the aqueous cleaning composition has a pH of from 1 to 4.

[0017] The aqueous cleaning composition of the present disclosure is characterized by a reduced volatile organic compound (VOC) content as compared to conventional cleaning compositions which find utility in the manufacturing of footwear. Despite this lowered VOC content, the aqueous composition demonstrates efficacious wetting of substrates conventionally found in footwear, including low surface energy polymeric substrates. It is evident that the cleaning composition is simple to prepare and apply and moreover demonstrates an operable drying profile.

[0018] In certain embodiments of the aqueous cleaning composition, constituent b) comprises or consists of at least one quaternary ammonium compound.

[0019] In some embodiments, constituent b) comprises at least one quaternary ammonium compound conforming to the formula (Qa):

[0020] (Rla)(R2a)(R3a)(R4a)N+X- (Qa)

[0021] wherein: X-is a counter anion; and, Rlato R4aare the same or different and are independently selected from Ci-C20 alkyl, Ci -C20 hydroxyalkyl, C1-C20 alkoxyalkyl, C1-C20 alkenyl, Ce-Cis aryl, C7-C18 alkaryl or C7-C18 aralkyl. In certain embodiments: X" is selected from the group consisting of halides, sulphate, methyl sulphate, ethyl sulphate and sulphonates; and, Rlato R4aare independently selected from Ci-Cis alkyl, Ci-Cis hydroxyalkyl, Ci-Cis alkoxy or Ci-Cis alkenyl. In other embodiments: X" is halide; and, Rlato R4aare independently selected from Ci-Cis alkyl, Ci-Cis hydroxyalkyl or Ci-Cis alkoxy.

[0022] In some embodiments, constituent b) comprises at least one quaternary ammonium compound conforming to the formula (Qb):

[0023] (Rlb)(R2b)(R3b)(R4b)N+X- (Qb)

[0024] wherein: X" is a counter anion; Rlband R2bmay together form a saturated, unsaturated or heteroaromatic ring together with the nitrogen atom to which they are bonded; and, R3bto R4bare the same or different and areindependently selected from C1-C20 alkyl, C1-C20 hydroxyalkyl, C1-C20 alkoxyalkyl, C1-C20 alkenyl, Ce-Cis aryl, C7-C18 alkaryl or C7-C18 aralkyl.

[0025] In still further embodiments, constituent b) comprises at least one quaternary ammonium compound confirming to the formula (Qc):

[0026] (R1C)(R2C)(R3C)(R4C)N+X- (Qc)

[0027] wherein: X" is selected from halide, sulphate, methyl sulphate, ethyl sulphate or sulphonate; Rlcis C4-C18 alkyl or C4-C18 alkenyl; R2cand R3care independently selected from C1-C4 alkyl; R4cis C1-C4 alkyl or C1-C4 hydroxyalkyl. Having regard to this embodiment it is preferred that: X" is selected from halide, sulphate, methyl sulphate, ethyl sulphate or sulphonate; Rlcis C4-C18 alkyl or C4-C18 alkenyl; R2cand R3care independently selected from C1-C2 alkyl; and, R4cis C1-C2 alkyl or C1-C2 hydroxyalkyl. Moreover, it is particularly preferred that: X is halide; Rlcis Cs-Cie alkyl or Cs-Cie alkenyl; R2cand R3care independently selected from C1-C2 alkyl; and, R4cis C1-C2 alkyl.

[0028] The aqueous cleaning composition may desirably be further characterized in that the ratio by weight of water to constituent c) said at least one water-miscible organic solvent is from 20:80 to 50:50, for example from 30:70 to 50:50.

[0029] Independently of, or additional to this preferred ratio by weight, it is preferred that constituent c) comprises or consists of at least one ketone. In exemplary embodiments constituent c) comprises or consists of acetone and methyl ethyl ketone.

[0030] In accordance with a second aspect of the invention, there is provided a formulated wipe which is impregnated with the aqueous cleaning composition as described herein above and in the appended claims.

[0031] In accordance with a further aspect of the invention, there is provided the use of the aqueous cleaning composition as defined herein above and in the appended claims in the manufacture of footwear. More particularly, the present invention provides for the use of the aqueous cleaning composition for the cleaning of polymeric substrates of footwear such as, but not limited to, molded polymeric substrates of which specific mention may be made of shoe outsoles, shoe midsoles and shoe insoles.

[0032] Where the aspects of the disclosure are described above as having certain embodiments, any one or more of those embodiments can be implemented in or combined with any one of the further embodiments, even if that combination is not explicitly described. Expressed differently, the described embodiments are not mutually exclusive, and permutations thereof remain within the scope of this disclosure.

[0033] DEFINITIONS

[0034] The words “a” and “an” generally carry a meaning of “one or more,” unless stated otherwise.The terms “ comprising” , “comprises” and “comprised of as used herein are synonymous with “including” , “includes”, “containing” or “contains”, and are inclusive or open-ended and do not exclude additional, nonrecited members, elements or method steps. If used, the phrase "consisting of is closed, and excludes all additional elements. Further, the phrase "consisting essentially of’ excludes additional material elements, but allows the inclusions of non-material elements that do not substantially change the nature of the invention. For completeness, the term “comprising” encompasses “consisting of .

[0035] When amounts, concentrations, dimensions and other parameters are expressed in the form of a range, a preferable range, an upper limit value, a lower limit value or preferable upper and limit values, it should be understood that any ranges obtainable by combining any upper limit or preferable value with any lower limit or preferable value are also specifically disclosed, irrespective of whether the obtained ranges are clearly mentioned in the context.

[0036] The words “preferable” , "preferred" , "preferably", “particularly” and “desirably” and synonyms thereof are used frequently herein to refer to embodiments of the disclosure that may afford particular benefits, under certain circumstances. However, the recitation of one or more preferable, preferred, particular or desirable embodiments does not imply that other embodiments are not useful and is not intended to exclude those other embodiments from the scope of the disclosure.

[0037] As used throughout this application, the word “may” is used in a permissive sense - that is meaning to have the potential to - rather than in the mandatory sense.

[0038] As used herein, room temperature is 23°C plus or minus 2°C.

[0039] Viscosities of the composition compositions may be determined using the Brookfield Viscometer, Model RVT at standard conditions of 25 °C and 50% Relative Humidity (RH). The viscometer is calibrated using silicone oils of known viscosities, which vary from 5,000 cps to 50,000 cps. A set of RV spindles that attach to the viscometer are used for the calibration. Measurements of the aqueous cleaning compositions are done using the No. 6 spindle at a speed of 20 revolutions per minute for 1 minute until the viscometer equilibrates. The viscosity corresponding to the equilibrium reading is then calculated using the calibration.

[0040] As used herein, number average molecular weight (Mn) and weight average molecular weight (Mw) are determined by gel permeation chromatography (GPC) with tetrahydrofuran (THF) as the eluent in accordance with DIN 55672-1:2007-08. The term polydispersity (PD) is derived from Mw and Mn and is calculated as (Mw / Mn).

[0041] The term “at least a fraction” is used herein in the context of representing an amount of a constituent, condition or parameter and specifically encompasses 100% of the defined constituent. The term “at least a fraction”includes: at least 5%; at least 10%; at least 15%; at least 20%; at least 25%; at least 30%; at least 35%; at least 40%; at least 45%; at least 50%; at least 55%; at least 60%; at least 65%; at least 70%; at least 75%; at least 80%; at least 85%; at least 90%; at least 95%; or, 100% of the defined constituent, condition or parameter.

[0042] The term “fraction” per se refers to a numerical quantity which defines a part up to but not including 100 percent or the entirety of the thing in question.

[0043] Unless otherwise stated, the term “particle size” refers to the largest axis of the particle. In the case of a generally spherical particle, the largest axis is the diameter.

[0044] The term “median volume particle size” (Dv50), as used herein, refers to a particle size corresponding to 50% of the volume of the sampled particles being greater than and 50% of the volume of the sampled particles being smaller than the recited Dv50 value. Particle size is determined herein by laser diffraction.

[0045] The term "aqueous cleaning composition" as used herein refers to that composition which actually contacts the surface to be cleaned. As is known in the art, such contacting can occur in a so-called "bath" which is shaped, sized and disposed to enable at least part of the substrate to be immersed therein. The bath should moreover be sized to allow for movement of the aqueous cleaning composition around and throughout a loaded substrate, which movement can be further enhanced with recirculation and / or ultrasonics. The pH of the composition within the bath, the temperature of the bath, and contact time with the substrate surface are result effective variables which should be monitored either manually or automatically, whenever possible.

[0046] The term “contact time” refers to the time period over which the aqueous cleaning composition contacts the substrate surface. The contact time commences when at least a fraction of the composition contacts said substrate surface. In certain embodiments, the contact time may be determined by the flow rate of the aqueous cleaning composition.

[0047] .As used herein "solvents" are substances capable of dissolving another substance to form a uniform solution; during dissolution neither the solvent nor the dissolved substance undergoes a chemical change. Solvents may either be polar or non-polar.

[0048] Water, for use as a (co-)solvent herein, is intended to mean water of low solids content as would be understood by a person of ordinary skill in the art. The water may, for instance, be distilled water, demineralized water, deionized water, reverse osmosis water, boiler condensate water, or ultra-filtration water. Tap water may be tolerated in certain circumstances.

[0049] The term "water-miscible organic solvent", as used herein, refers to an organic solvent that is completely miscible with water at room temperature. In this regard, a particular preference may be noted for organic solventswhich are soluble, freely soluble or very soluble in water and are thereby characterized by requiring < 30 ml of water to dissolve 1 g of organic solvent at room temperature (https: / / www.sigmaaldrich.com / united-kingdom / technical-services / solubility.html).

[0050] The term "water-immiscible organic solvent”, as used herein refers to organic solvents that form a two-phase system with water. In this regard, a particular preference may be noted for organic solvents which are slightly soluble, very slightly soluble or practically insoluble in water and are thereby characterized by requiring > 100 ml of water to dissolve 1 g of organic solvent at room temperature (https: / / www.sigmaaldrich.com / united-kingdom / technical-services / solubility.html).

[0051] As used herein, the term “volatile organic compound” (VOC) is defined as a carbon-containing compound that has a boiling point below 250° C. at atmospheric pressure.

[0052] Measurement of the VOC emissions of the compositions of the present invention should be conducted in accordance with ISO 11890-2: 2006. The measurement conditions of this ISO norm should be directed to quantitatively measure the full content of VOC. The VOC should be expressed in weight % of the total formulation i.e. water is included in the total formulation and in the VOC calculation as well.

[0053] Measurement of the solids content of coating or coating materials is conducted in accordance with EPA Test Method 24 (40 CFR 60, Appendix A).

[0054] If an organic liquid product has a boiling point region, then the onset (the lowest temperature) of the boiling point range at atmospheric pressure is taken as the nominal boiling point. Where necessary any measurement of the initial boiling point for materials should be conducted in accordance with ASTM Standard Test Method D1078-95, or its most current version.

[0055] As used herein, the term “dispersion” refers to a composition that contains discrete particles that are distributed throughout a continuous liquid medium.

[0056] As used herein, the term “surface tension” refers to the force required to increase the unit area of a surface of a liquid or of an interface between two liquids or between a liquid and a gas, generally stated in units of dynes / cm. Surface tensions described herein are measured by the Du Noiiy ring method utilizing an Easy Dyne tensiometer model K20 marketed by Kriiss USA, Matthews, N.C.

[0057] All percentages, ratios and proportions used herein are given on a weight basis unless otherwise specified. As used herein, "phosphoric acid" refers to ortho-phosphoric acid having the formula H3PO4, which acid is typically available as an aqueous solution having a concentration up to 75 wt.% H3PO4. As used herein “phosphonic acid’ refers to the phosphorus oxoacid having the formula H3PO3 that consists of a singlepentavalent phosphorus covalently bound via single bonds to a single hydrogen and two hydroxy groups and via a double bond to an oxygen.

[0058] As used herein, "Ci-Cnalkyl" group refers to a monovalent group that contains 1 to n carbons atoms, that is a radical of an alkane and includes straight-chain and branched organic groups. As such, a "C1-C4 alkyl" group refers to a monovalent group that contains from 1 to 4 carbons atoms, that is a radical of an alkane and includes straight-chain and branched organic groups. Examples of alkyl groups include, but are not limited to: methyl; ethyl; propyl; isopropyl; n-butyl; isobutyl; sec-butyl; and, tert-butyl. In the present invention, such alkyl groups may be unsubstituted or may be substituted with one or more halogen. Where applicable for a given moiety (R), a tolerance for one or more non-halogen substituents within an alkyl group will be noted in the specification. The terms “ alkylene group" refers to a group that are radicals of a linear, branched or cyclic alkane, which group may be substituted or unsubstituted and may optionally be interrupted by at least one heteroatom.

[0059] The term “C;-C„ hydroxyalkyl” as used herein refers to an HO-(alkyl) group having from 1 to n carbon atoms, where the point of attachment of the substituent is through the oxygen-atom and the alkyl group is as defined above.

[0060] An “ alkoxy group” refers to a monovalent group represented by -OA where A is an alkyl group: non-limiting examples thereof are a methoxy group, an ethoxy group and an iso-propyloxy group. The term " alkoxylatecT as used herein means comprising at least one alkoxy group.

[0061] As used herein, “C2-C„ alkenyl” group refers to an aliphatic carbon group that contains 2 to n carbon atoms and at least one double bond disposed in any position. The alkenyl group can be straight chained, branched or cyclic and may optionally be substituted with one or more halogen. Where applicable for a given moiety (R), a tolerance for one or more non-halogen substituents within an alkenyl group will be noted in the specification. The term “alkenyl” also encompasses radicals having “cis” and “trans” configurations, or alternatively, “E” and “Z” configurations, as appreciated by those of ordinary skill in the art. In general, however, a preference for unsubstituted alkenyl groups containing from 2 to 6 (C2-Ce) or from 2 to 4 (C2-C4) carbon atoms should be noted. And Examples of C2-C6 alkenyl groups include, but are not limited to: ethenyl; 1 -propenyl; 2-propenyl; 1-methyl-ethenyl; 1-butenyl; 2-butenyl; 4-methylbutenyl; 1 -pentenyl; 2-pentenyl; 3-pentenyl; 4-pentenyl; 4-methyl-3 -pentenyl; 1 -hexenyl; 3-hexenyl; and, 5-hexenyl.

[0062] The term “Ci-Ce cycloalkyl” as used herein means an optionally substituted, saturated cyclic hydrocarbon having 3-6 carbon atoms. In the present invention, such cycloalkyl groups may be unsubstituted or may be substituted with one or more halogen. Where applicable for a given moiety (R), a tolerance for one or more non-halogen substituents within a cycloalkyl group will be noted in the specification. Exemplary cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl groups.As used herein, “Cj-Cg cycloalkylene” means a divalent radical formed by the removal of two hydrogen atoms from one or more rings of a cycloalkyl group having from 3 to 6 carbon atoms.

[0063] As used herein, "C2-C18 alkenyl" refers to hydrocarbyl groups having from 2 to 18 carbon atoms and at least one unit of ethylenic unsaturation. The alkenyl group can be straight chained, branched or cyclic and may optionally be substituted with one or more halogen. Where applicable for a given moiety (R), a tolerance for one or more non-halogen substituents within an alkenyl group will be noted in the specification. The term “alkenyl” also encompasses radicals having “cis” and “trans” configurations, or alternatively,

[0064]

[0065] and “Z” configurations, as appreciated by those of ordinary skill in the art. Examples of said C2-C20 alkenyl groups include, but are not limited to: — CH=CH2; — CH=CHCH3; — CH2CH=CH2; — C(=CH2)(CH3); — CH=CHCH2CH3; — CH2CH=CHCH3; — CH2CH2CH=CH2; — CH=C(CH3)2; — CH2C(=CH2)(CH3); — C(=CH2)CH2CH3; — C(CH3)=CHCH3; — C(CH3)CH=CH2; — CH=CHCH2CH2CH3; — CH2CH=CHCH2CH3;— CH2CH2CH=CHCH3; — CH2CH2CH2CH=CH2; — C(=CH2)CH2CH2CH3; — C(CH3)=CHCH2CH3; — CH(CH3)CH=CHCH;— CH(CH3)CH2CH=CH2; — CH2CH=C(CH3)2; 1 -cyclopent- 1-enyl; l-cyclopent-2-enyl; l-cyclopent-3-enyl; 1 -cyclohex- 1-enyl; 1 -cyclohex-2 -enyl; and, l-cyclohexyl-3-enyl.

[0066] As used herein, an “Cs-Cis aryl” group used alone or as part of a larger moiety - as in “aralkyl group” - refers to monocyclic, bicyclic and tricyclic ring systems in which the monocyclic ring system is aromatic or at least one of the rings in a bicyclic or tricyclic ring system is aromatic. The bicyclic and tricyclic ring systems include benzofused 2-3 membered carbocyclic rings. In the present disclosure, such aryl groups may be unsubstituted or may be substituted with one or more halogen. Where applicable for a given moiety (R), a tolerance for one or more non-halogen substituents within an aryl group will be noted in the specification. Exemplary aryl groups include: phenyl; (C1-C4) alkylphenyl, such as tolyl and ethylphenyl; indenyl; naphthalenyl, tetrahydronaphthyl, tetrahydroindenyl; tetrahydroanthracenyl; and, anthracenyl.

[0067] As used herein, "alkylaryl" refers to alkyl-substituted aryl groups and "substituted alkylaryl" refers to alkylaryl groups further bearing one or more substituents as set forth above. Further, as used herein "aralkyl" means an alkyl group substituted with an aryl radical as defined above.

[0068] The term "hetero" as used herein refers to groups or moieties containing one or more heteroatoms, such as N, O, Si and S. Thus, for example "heterocyclic" refers to cyclic groups having, for example, N, O, Si or S as part of the ring structure. "Heteroalkyl" , "heterocycloalkyl" and “heteroaryl” moieties are alkyl, cycloalkyl and aryl groups as defined hereinabove, respectively, containing N, O, Si or S as part of their structure.

[0069] The term "heterocyclyl" refers to a monovalent chain of carbon and heteroatoms, wherein the heteroatoms are selected from N, O, Si or S, a portion of which, including at least one heteroatom, form a ring.The term “ substituted" refers to substitution with at least one suitable substituent. For completeness: the substituents may connect to the specified group or moiety at one or more positions; and, multiple degrees of substitution are allowed unless otherwise stated. Further, the terms “substitution” or “substituted with” include the implicit proviso that such substitution is in accordance with permitted valence of the substituted atom and the substituent, and that the substitution results in a stable compound that does not spontaneously undergo transformation by, for instance, rearrangement, cyclization or elimination.

[0070] The present compositions may be defined herein as being “substantially free” of certain compounds, elements, ions or other like components. The term “substantially free” is intended to mean that the compound, element, ion or other like component is not deliberately added to the composition and is present, at most, in only trace amounts which will have no (adverse) affect on the desired properties of the coating. An exemplary trace amount is less than 1000 ppm by weight of the composition. The term “substantially free” encompasses the term “free”, the latter term indicating those embodiments where the specified compound, element, ion, or other like component is completely absent from the composition or is not present in any amount measurable by techniques generally used in the art.

[0071] BRIEF DESCRIPTION OF THE DRAWING

[0072] The present invention will be described with reference to the appended drawing in which:

[0073] Fig. 1 is an illustration of an exemplary shoe as known in the art.

[0074] DETAILED DESCRIPTION

[0075] As described above, the present disclosure is directed to an aqueous cleaning composition comprising: water; a) phosphoric acid; b) at least one cationic surfactant; and, c) at least one water-miscible organic solvent, wherein the aqueous cleaning composition has a pH of from 1 to 5.

[0076] a) Phosphoric Acid

[0077] The aqueous composition comprises phosphoric acid. In an embodiment, the aqueous cleaning composition may comprise, based on the weight of the composition, from 0.05 to 2 wt.% of a) said phosphoric acid. For example, the aqueous cleaning composition may comprise from 0.05 to 1 wt.% or from 0.1 to 1 wt.% of a) said phosphoric acid, based on the weight of the composition.

[0078] In certain embodiments, which are not intended to be mutually exclusive of the preferred weight ranges given above, the added amount of phosphoric acid should be such that the aqueous cleaning composition has a pH of from 1 to 5, for example from 1 to 4 or from 2 to 4.b) Cationic Surfactant

[0079] The present aqueous cleaning compositions comprise b) at least one cationic surfactant. The aqueous cleaning compositions may typically comprise from 0.1 to 5 wt.% of b) said at least one cationic surfactant, based on the total weight of the aqueous composition. For example, the aqueous cleaning composition may comprise from 0.1 to 2 wt.%, from 0.1 to 1 wt.% or from 0.1 to 0.5 wt.%, based on the total weight of the aqueous composition. Exemplary cationic surfactants, which may be used alone or in combination include: ammonium compounds derived from fatty amines; quaternary ammonium compounds; and, monomeric biguanide compounds such as, but not limited to chlorhexidine, alexidine and salts thereof. The use of quaternary ammonium compounds in the aqueous cleaning composition may be mentioned in particular.

[0080] Fatty amines may contain from 1 to 3 short chain or long chain alkyl groups, aryl groups and / or heterocyclic groups attached to a nitrogen atom - of the amino group - and have a pH of greater than 7.0. The treatment of the fatty amines with acid produces fatty amine salts which are weakly cationic. The reaction between tertiary fatty amines - wherein three hydrophobic groups are attached to the amino nitrogen atom - and alkyl halides produces quaternary ammonium compounds. This reaction or quatemization forms a permanently charged species which is stable to variations in pH. The charged species is conventionally soluble in water but the solubility of the fatty acid salts and quaternary ammonium compounds in aqueous systems is dependent upon the size of the molecule or, more particularly, the length and number of hydrophobic chains, relative to the charge on the molecule.

[0081] Fatty amine salts, and quaternary ammonium compounds have the respective generic formulae:

[0082] Fatty Amines (FA): (R')(R2)(R3)N

[0083] Fatty Amine Salts (FAS) : [(R’)(R2)(R3)NH]+X- Quatemary Ammonium Salt (Q): [(R')(R2)(R3)(R4)N]+X_

[0084] wherein: X" is a counter anion; and,

[0085] R1to R4are the same or different and are independently selected from aliphatic, cycloaliphatic or aromatic groups.

[0086] In a first exemplary embodiment, the aqueous cleaning composition may comprise at least one quaternary ammonium compound conforming to the formula (Qa):

[0087] (Rla)(R2a)(R3a)(R4a)N+X' (Qa)

[0088] wherein: X" is a counter anion; and,

[0089] Rlato R4aare the same or different and are independently selected from C1-C20 alkyl, C1-C20 hydroxyalkyl, C1-C20 alkoxyalkyl, C1-C20 alkenyl, Ce-Cis aryl, C7-C18 alkaryl or C7 -Cis aralkyl.Having regard to quaternary ammonium compounds of Formula (Qa) having utility in the present disclosure, it is preferred that: Rlato R4aare independently selected from Ci-Cis alkyl, Ci-Cis hydroxyalkyl, Ci-Cis alkoxy or Ci-Cis alkenyl. In particular for said quaternary ammonium compounds of Formula (Qa), Rlato R4amay be independently selected from Ci-Cis alkyl, Ci-Cis hydroxyalkyl or Ci-Cis alkoxy.

[0090] Independently of or additional to this statement of preference for substituents Rlato R4aof the quaternary ammonium compounds of Formula (Qa), X" may desirably be selected from the group consisting of: halides, in particular chloride or bromide; sulphate; methyl sulphate; ethyl sulphate; and, sulphonates, in particular toluene sulphonate. A preference may be mentioned for X" being halide and, more particularly, chloride.

[0091] In accordance with the aforementioned general formulae, exemplary quaternary ammonium compounds in accordance with Formula (Qa) having utility in the present disclosure include the following salts with counteranion X": tetra(C4-Cis)alkylammonium salts, such as tetrabutylammonium chloride; (C4-Cis)alkyltrimethylammonium salts; di(C4-Cis)alkyldimethyl ammonium salts, such as dioctyldimethyl ammonium chloride and didecyl dimethyl ammonium chloride; (C4-Ci8)alkyl(C6-Cis)arylmethylammonium salts; (C4-Ci8)alkyl(C7-Cis)aralkylammonium salts, such as octyldimethylbenzyl ammonium chloride; (C4-Ci8)alkylpryidinium salts; and, (C4-Ci8)alkyl(Ci-C2)alkylmorpholinium salts.

[0092] In a second exemplary embodiment, which is not mutually exclusive of that given above, the aqueous cleaning composition may comprise at least one quaternary ammonium compound conforming to the formula (Qb):

[0093] (Rlb)(R2b)(R3b)(R4b)N+X- (Qb)

[0094] wherein: X" is a counter anion;

[0095] Rlband R2bmay together form a saturated, unsaturated or heteroaromatic ring together with the nitrogen atom to which they are bonded; and,

[0096] R3bto R4bare the same or different and are independently selected from C1-C20 alkyl, C1-C20 hydroxyalkyl, C1-C20 alkoxyalkyl, C1-C20 alkenyl, Ce-Cis aryl, C7-C18 alkaryl or C7 -Cis aralkyl.

[0097] In a still further exemplary embodiment, which is also not mutually exclusive of those given above, the aqueous composition comprises at least one quaternary ammonium compound having the general formula (Qc)

[0098] (R1C)(R2C)(R3C)(R4C)N+X- (Qc)

[0099] wherein: Rlcis C4-18 alkyl or C4-C18 alkenyl;

[0100] R2cand R3care independently selected from C1-C4 alkyl;

[0101] R4Cis C1-C4 alkyl or C1-C4 hydroxyalkyl; and,

[0102] X-is selected from halide, sulphate, methyl sulphate, ethyl sulphate or sulphonate.

[0103] In particular embodiments of the quaternary ammonium compounds in accordance with Formula (Qc): Rlcis C4-Cis alkyl or C4-C18 alkenyl; R2cand R3care independently selected from C1-C2 alkyl; and, R4cis C1-C2 alkyl orC1-C2 hydroxy alkyl. In exemplary quaternary ammonium compounds in accordance with Formula (Qc): Rlcis Cs-Cie alkyl or Cs-Cie alkenyl; R2cand R3care independently selected from C1-C2 alkyl; and, R4cis C1-C2 alkyl. Illustrative quaternary ammonium compounds in accordance with Formula (Qc) and which may be used alone or in combination in the aqueous cleaning compositions, include: cetyl (Cie) trimethylammonium chloride (CETAC); and, pentyl (C5) trimethyl ammonium chloride.

[0104] Suitable quaternary ammonium compounds may be obtained from commercial sources, of which examples include: BTC 1010, BTC 1210, BTC 818 and BTC 8358, available from Stepan Co; and Dehyquart A CA, available from BASF.

[0105] It is not precluded that the present aqueous cleaning compositions may comprise at least one further surfactant selected from the group consisting of: zwitterionic surfactants; non-ionic surfactants; and, mixtures thereof. The aqueous composition may, for example, comprise in toto from 0 to 1 wt.% or from 0 to 0.5 wt.%, of said further surfactants, based on the total weight of the aqueous composition. For completeness, it is preferred that the aqueous cleaning composition is substantially free of anionic surfactants.

[0106] In an embodiment, the further surfactant(s) included in the composition comprise, consist essentially or consist of non-ionic surfactant. The or each further surfactant included in the composition may, in an embodiment, be non-ionic. Non-ionic surfactants used in the aqueous cleaning composition may be characterized by a number average molecular weight (Mn) of from 2000 to 20000 daltons, for example from 2000 to 10000 daltons or from 2000 to 8000 daltons. Exemplary non-ionic surfactants include: polyethylene oxides, such as PEG 300 or PEG 400; fatty alcohols; primary alcohol (C2-C4)alkoxylates; secondary alcohol (C2-C4)alkoxylates; alkylphenol (C2-C4)alkoxylates; alkylamino (C2-C4)alkoxylates; amine poly glycol condensates, such as Triton® CF-32 available from the Dow Chemical Company; polyoxy(C2-C3)alkylene fatty acid esters; polysorbates; sodium lauryl sulfate; sorbitan monolaurate; sorbitan monooleate; sorbitan monopalmitate; sorbitan trioleate; and, silicone surfactants, such as silicone poly ether copolymers.

[0107] c) Water-Miscible Organic Solvent

[0108] The aqueous composition comprises c) at least one water-miscible organic solvent. The aqueous composition may comprise, based on the weight of the composition, from 20 to 90 wt.% of c) said at least one water-miscible solvent. For example, the composition may comprise from 30 to 90 wt.%, from 40 to 80 wt.% or from 50 to 80 wt.% of c) said at least one water-miscible solvent, based on the weight of the composition.

[0109] In an alternative expression of preference, which is not intended to be mutually exclusive of the compositional ranges mentioned above, the water and c) said at least one water-miscible organic solvent may be present in theaqueous cleaning composition at a ratio by weight of from 20:80 to 50:50, for example from 30:70 to 50:50. In an additional statement of preference, which is not intended to be mutually exclusive of those ratios mentioned above, it is preferred that the water-miscible organic solvent or the mixture of water-miscible organic solvents included in constituent c) are selected and added to water in an amount sufficient to reduce the surface tension of the water / solvent combination to less than 64 dynes / cm at room temperature.

[0110] The at least one water-miscible organic solvent of the present invention may be selected from the group consisting of: Ci-e alkanols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tertbutanol, n-pentanol; cyclopentanol; cyclohexanol; diols, particularly diols having from 2 to 12 carbon atoms such as ethylene glycol, propylene glycol, butylene glycol, 1,5 -pentanediol, pentylene glycol, hexylene glycol but also including thiodiglycol and oligo- and poly-alkyleneglycols, such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol and polypropylene glycol; triols such as 1,2,6-hexanetriol; ketones and ketone-alcohols; tetrahydrofuran; dioxane; mono-Ci-4-alkyl ethers of diols having from 2 to 12 carbon atoms, such as ethylene glycol mono-(Ci-C4)-alkyl ethers, propylene glycol mono-(Ci-C4)alkyl ethers and in particular ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether; diethylene glycol mono-(Ci-C4)alkyl ethers, such as diethylene glycol monomethyl ether and diethylene monobutyl ether; dipropylene glycol mono-(Ci-C4)alkyl ethers, such as dipropylene glycol N-propyl ether, dipropylene glycol monopropyl ether and dipropylene glycol monobutyl; propylene glycol phenyl ether; linear amides, such as N,N-dimethylformamide and N,N-dimethylacetamide; cyclic amides such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, caprolactam and 1,3-dimethylimidazolidone; sugar esters, such as dimethyl isosorbide; cyclic esters such as caprolactone; and, sulfoxides, such as dimethyl sulfoxide and sulfolane.

[0111] In an important embodiment, said at least one water-miscible solvent comprises at least one ketone. Exemplary ketones, which may be used alone or in combination, include: acetone; methyl ethyl ketone; 2-pentanone; 3-pentanone; methyl isobutyl ketone; and, cyclohexanone. The use of acetone and methyl ethyl ketone, either alone or desirably in combination, may be mentioned in particular. For example, constituent c) of the aqueous cleaning composition may comprise methyl ethyl ketone and acetone, wherein the ratio by weight of methyl ethyl ketone to acetone is from 1:3 to 3:1, such as from 1:2 to 2:1 or from 1.5:1 to 1:1.5.

[0112] d) Adjunct Ingredients

[0113] The aqueous cleaning compositions of the present disclosure may further comprise adjuvants and additives that can impart improved properties to these compositions. The adjuvants and additives may, for instance, impart one or more of: reduced drying time; reduced corrosiveness; improved stability; and, longer shelf-life of the compositions. Such adjuvants and additives can be used in such combination and proportions as desired, provided they do not adversely affect the nature and essential properties of the composition. While exceptionsmay exist in some cases, these adjuvants and additives should not in toto comprise more than 5 wt.% of the total weight of the aqueous cleaning composition.

[0114] Included among such adjuvants and additives are: non-ionic and zwitterionic surfactants as mentioned above; stabilizers, including UV stabilizers; biocides; and, rheological adjuvants for moderating the viscosity or thixotropic properties of the aqueous cleaning compositions and of which examples include thickeners, cosolvents and non-reactive diluents. As regards any additive or adjunct material, it is preferred that said material possess a flash point of at least 60°C, for example at least 75°C.

[0115] "Stabilizers" for the purposes of this disclosure are understood to be materials that reduce the tendency of the aqueous composition to separate into two phases. When present, stabilizers may constitute in toto up to 2 wt.%, for instance from 0.1 to 1 wt.%, based on the total weight of the aqueous compositions. Standard examples of stabilizers suitable for use herein include: lecithin; phospholipids; and, grafted or crosslinked silicone polymers.

[0116] One or more biocides may be present in the aqueous composition to control microbial growth. Biocides may constitute in toto from 0 to 1 wt.%, for instance from 0.01 to 1 wt.%, based on the weight of the emulsion. Examples of suitable biocides include but are not limited to: 5-chloro-2-methyl-4-isothiazolin-3-one; 2-methyl-4-isothiazolin-3-one; glutaraldehyde; 2,2-dibromo-3-nitrilopropionamide; 2-bromo-2 -nitropropane- 1,3 diol; 1-bromo-l-(bromomethyl)-l,3-propanedicarbonitrile; tetrachloroisophthalonitrile; alkyldimethylbenzyl ammonium chloride; dimethyl dialkyl ammonium chloride; poly(oxyethylene(dimethyliminio)ethylene (diemethyliminio)ethylene dichloride; methylene bisthiocyanate; 2-decylthioethanamine; tetrakishydroxymethyl phosphonium sulfate; dithiocarbamate; cyanodithioimidocarbonate; 2-methyl-5-nitroimidazole-1 -ethanol; 2-(2-bromo-2-nitroethenyl)furan; beta-bromo-beta-nitrostyrene; beta-nitrostyrene; beta-nitrovinyl furan; 2-bromo-2-bromomethyl glutaronitrile; bis(trichloromethyl)sulfone, S-(2-hydroxypropyljthiomethanesulfonate; tetrahydro-3, 5-dimethyl-2H-l, 3, 5-hydrazine-2-thione; 2- (thiocyanomethylthio)benzothiazole; 2-bromo-4'-hydroxyacetophenone; l,4-bis(bromoacetoxy)-2-butene; bis(tributyltin)oxide; copper sulfate; (2-tert-butylamino)-4-chloro-6-(ethylamino)-s-triazine; dodecylguanidine acetate; dodecylguanidine hydrochloride; coco alkyldimethylamine oxide; n-coco alkyltrimethylenediamine; tetra-alkyl phosphonium chloride; 7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid; 2-(4-thiazolyl)-benzimidazole; orthophenylphenol; 6-ethoxy-l,2-dihydro-2,2,4-trimethyl quinoline; and, 4,5-dichloro-2-n-octy l-4-isothiazoline-3 -one .

[0117] Thickeners represent an optional component of the present aqueous cleaning compositions and may constitute from 0 to 2 wt.% or from 0 to 1 wt.%, based on the total weight of the composition. Exemplary thickeners include but are not limited to: cellulosic thickeners and their derivatives; natural gums, such as guar gum, karaya gum, locust bean gum, carrageenan, tragacanth gum and xanthan gum; starches; stearates; fatty alcohols; hydrophobically modified alkali-soluble emulsion polymers (HASE); hydrophobically modified urethane-ethoxylate resins (HEUR); and, acrylic acid polymers and cross-polymers. The use of cellulosic thickeners and their derivatives may in particular be mentioned, of which examples include: carboxymethyl hydroxyethylcellulose; cellulose, hydroxybutyl methylcellulose; hydroxyethylcellulose; hydroxypropylcellulose; hydroxypropyl methyl cellulose; methylcellulose; microcrystalline cellulose; and, sodium cellulose sulfate.

[0118] Preparation of the Aqueous Compositions

[0119] To form the defined aqueous cleaning compositions, the parts are brought together and mixed. It is important that the mixing homogenously distributes the ingredients within the composition: the mixing is thus not usually conducted by hand but is instead performed using either a static mixer, dynamic mixer, colloid mill, rotor-stator homogenizer or an ultrasonic probe. Whilst the order in which the constituent ingredients are mixed and the temperature of mixing may not typically be germane, it may of course be varied to ensure the homogeneity of the mixture. Further, soluble components may also be added as one or more pre-prepared solution or may be added in neat form but under mixing conditions which ensure that the components are in dissolved form in the final aqueous cleaning composition. Still further, the mixing procedure may, in some embodiments, be carried out at reduced pressure to limit or prevent entrainment of air.

[0120] If necessary, the aqueous cleaning compositions may be prepared well in advance of their application. However, in an interesting alternative embodiment, a concentrated composition may first be obtained by mixing components with only a fraction of the water that would be present in the composition as applied: the concentrated composition may then be diluted with the remaining water shortly before its application. It is considered that such concentrated compositions may be prepared and stored as either single-package concentrates - that can be converted by dilution with water only - or as multi-part concentrates, two or more of which must be combined and diluted to form a complete working composition according to the invention. Any dilution can be effected simply by the addition of water, in particular deionized and / or demineralized water, under mixing. The aqueous cleaning composition might equally be prepared within a rinse stream whereby one or more streams of the concentrate(s) is injected into a continuous stream of water.

[0121] Without specific intention to limit the amount of water included in the aqueous cleaning compositions, it is preferred that said compositions contain from 10 to 60 wt.%, preferably from 10 to 50 wt.% and more preferably from 20 to 50 wt.%, based on the weight of the composition, of water. In an alternative but not mutually exclusive characterization, the aqueous cleaning composition may be defined by a viscosity of from 0.005 to 1 Pa.s (50 cps to 1000 cps), as measured using a Brookfield viscometer at 25 °C.

[0122] Preparation of Formulated WipesIn accordance with an aspect of the invention, there is provided a formulated wipe which is impregnated with the above described aqueous cleaning composition. The substrate used to make the formulated wipes is any substrate that can be impregnated with the aqueous cleaning composition - at least on its surface - to provide a suitable article for treatment of the surface concerned. As such, the substrate for the wipe is generally an absorbent or adsorbent material that is insoluble in the cleaning composition and which is not corrupted by that composition: a preference for wipes comprising or consisting of non-woven sheets might be mentioned.

[0123] Non-woven sheets typically contain at least one layer that is made of: natural fibers; one or more synthetic fibers; or, blends of natural fibers and said one or more synthetic fibers. Non-limiting examples of suitable synthetic fibers include: polyester fibers, such as polyethylene terephthalate fibers; rayon; viscose; polyamides, such as nylon; polyether sulphone (PES) fibers; polypropylene fibers; and, polyethylene fibers. Exemplary natural fibers including: wood pulp; cellulose polymers; and, starch. The constituent fibers of the sheet may be melt blown, co-formed, air laid, air gelled, spun bond, wet laid, bonded, dash-carded, hydro-entangled or otherwise formed into a sheet by a combination of said methods. A binder may or may not be present in the sheet.

[0124] Non-woven sheets may be characterized by an areal weight that is dependent on the density of the fibers making up the sheet and the relative number of fibers per unit area. Without intention to the limit the present invention, suitable non-woven sheets will typically have an areal weight from 5 to 200 g / m2, for example from 5 to 100 g / m2, from 20 to 80 g / m2or from 30 to 70 g / m2.

[0125] Aside from non-woven sheets, the use of other substrate materials capable of imbibing or impregnation with the cleaning solutions is not precluded. Such substrates might include: woven materials, such as those made from cotton fibers, from fibers of synthetic polymers, or from blends of cotton and synthetic fibers; and, foam materials, such as regenerated cellulose or polyurethane foams.

[0126] It is envisaged that the wipes can be individually sealed with a heat-sealable or glue-able thermoplastic overwrap. Equally, the wipes might be packaged as numerous individual sheets which are then impregnated or contacted with the cleaning solution for economical dispensing: such individual wipes may be nested or interleaved within the package such that the removal of one individual wipe advances the next wipe and so forth. Still further, the wipes might be formed as a continuous web during the manufacturing process and loaded into a suitable dispenser equipped with a closure - preferably a re-sealable closure - which functions to isolate the moistened wipes from the external environment. Such a dispenser may viably be provided with a means of sizing the desired length of the wipe form the continuous web, such as a knife blade or serrated edge. In alternative embodiments, the continuous web of wipes can be scored, perforated, folded, segmented, or partially cut into uniform or non-uniform sizes or lengths.There is no particular intention to limit the size and shape of the wipes. They should have dimensions suitable for use by a single person. Alternatively or additionally, the wipes should be small enough to be stored and transported easily, yet large enough to provide adequate treatment of the surface concerned.

[0127] The wipes are manufactured by applying the aqueous cleaning composition to a substrate by, for example, dipping, immersion or spraying. The amount of cleaning solution which is applied to the wipe can be varied to provide a desired loading of the components thereof and such variation might be effected by metering the solution during a spraying operation or by moving the substrate past an application source at a controlled rate. If necessary, excess solution can be removed from the wipe after application by shaking, rolling, drip drying and the like.

[0128] A further aspect of the present invention is constituted by a kit of parts which comprises the above described cleaning composition and a means for applying said composition. For instance, a suitable kit might comprise: a plurality of the formulated wipes as described hereinabove which are impregnated with the cleaning solution and disposed in a dispenser or packaging; and, instructions for the use of those wipes in written form, cartoon form, pictorial form or combinations thereof. Alternatively, a suitable kit may comprise: a container of the cleaning solution; a plurality of absorbent or adsorbent wipes; and, instructions for both the impregnation of those wipes with the cleaning composition and the subsequent use of the wipes. Kits may of course be provided with other items, including but not limited to : means to remove excess composition from the surface to be treated; and, protective clothing, masks and eye wear.

[0129] METHODS AND APPLICATIONS

[0130] Prior to applying the aqueous cleaning composition, it is not precluded that the relevant surfaces be physically and / or chemically pre-treated. Such treatments are known in the art and can be performed in a single or multistage manner constituted by, for instance, the use of one or more of: abrasion of the surface; roughening of the surface; feather edging of the surface; an etching treatment with an acid suitable for the substrate and optionally an oxidizing agent; sonication; plasma treatment, including chemical plasma treatment, corona treatment, atmospheric plasma treatment and flame plasma treatment; immersion in a degreasing bath; treatment with a cleaning solvent, such as acetone, carbon tetrachloride or trichloroethylene; and, water rinsing, preferably with deionized or demineralized water.

[0131] The aqueous cleaning compositions can be applied to a surface in any desired manner suitable for the particular surface. For example, the aqueous cleaning compositions can be applied by: at least partial immersion of the surface in the aqueous composition; dispensing of the aqueous cleaning composition onto the surface, including by pouring for instance; spraying of the aqueous cleaning composition onto the surface; and, wiping the surface with the aqueous cleaning composition as provided by a retaining substrate, such as a sponge, rag or the afore-described wipes. The methods of application are not mutually exclusive and more than one such method may be used.

[0132] The aqueous composition is typically applied to the surface(s) at ambient temperature. However, in certain circumstances, the temperature of the aqueous compositions may be elevated prior to application to, for instance, a temperature in the range of from 30°C to 90°C, for instance from 30°C to 70° C.

[0133] Independently of the method of application, the aqueous cleaning composition should contact the surface for a sufficient amount of time to remove at least a fraction of the soils on said surface. Effective contact times may be from 1 to 60 seconds, for example from 1 to 30 seconds or from 1 to 15 seconds. Whilst the rinsing of the surface after contacting with the aqueous cleaning composition is not precluded, this may not be required to achieve an effective removal of soils from the surface or may not be desired where the aqueous composition has positively modified the free energy of the cleaned surface.

[0134] The surface to which the aqueous cleaning composition has been applied may optionally be dried following an appropriate contact time. Drying may be performed at ambient temperatures, using for example ambient air drying. In the alterative, the temperature of the surface may be elevated using, for example, circulating warm air, forced air drying or infrared heating. The temperature of the substrate(s) surface should be controlled during any such drying to obviate any undesired physical, morphological or chemical changes to the surface.

[0135] The surface to which the cleaning composition is to be applied may, in certain embodiments, be provided by an article of footwear manufacture. With further reference to Figure 1 appended hereto, exemplary articles of footwear manufacture include, but are not limited to: uppers (2); counters (21); linings (22); vamps (22); toecaps (24); shoe unit-soles (3); heels (31); shoe outsoles (32); shoe midsoles (33); shoe insoles (34); over-molded articles; natural leather articles; synthetic leather articles; laminated articles; coated articles; boots; sandals; galoshes; and, plastic shoes. Articles of footwear manufacture which have been molded - and which may therefore comprise mold release agents and surface anti-adherend moieties - may be mentioned more particularly as providing candidate surfaces for the application of the aqueous cleaning compositions. Especially preferred surfaces to which the cleaning composition is applied to are the surfaces of shoe midsoles (33) and outsoles (32) that require a diligent cleaning prior to bonding of these substrates with each other and other components of the shoe unit sole (3) such as the insole (34). The shoe midsole (33) and the outsole (32) preferably both constitute polymeric substrates as further specified in the alternative expression of preference succeeding this paragraph whereby even more specifically the midsole (33) is preferably made from ethylene vinyl acetate copolymers and the shoe outsole (32) preferably made from rubbers as outlined in the following paragraphs.

[0136] In an alternative expression of preference, which is not intended to be mutually exclusive of that mentioned above, the surface to which the cleaning composition is applied may be provided by a polymeric substrate andmore particularly a polymeric substrate having a surface energy of from 20 to 60 dyne / cm. Exemplary polymeric substrates include, but are not limited to: ethylene vinyl acetate copolymers; polyorganosiloxanes; polyolefins, such as polyethylene and polypropylene; polyvinyl chloride; polystyrene; polyurethanes; and, rubbers.

[0137] Exemplary ethylene vinyl acetate copolymers may be characterized by at least one of: i) a percentage by weight of vinyl acetate, as determined in accordance with ASTM D5594 of from 5 to 40 wt.%; ii) a percentage by weight of ethylene of from 60 to 95 wt.%; iii) a melt flow index, as determined at 190°C and 2.16 kg in accordance with ASTM D1238, of from 1 to 45 dg / min; iv) a density, as determined in accordance with ASTM D792 of from 0.80 to 1.00 g / cm3; and, v) a Shore A hardness, as determined in accordance with ASTM D2240 of from 10 to 80. These characterizations are not mutually exclusive and one, two, three, four or five thereof may be applicable.

[0138] Exemplary rubbers include, but are not limited to: natural rubber; poly-isoprene (IR); styrene -butadiene rubber (SBR); poly butadiene; nitrile rubber (NBR); polyolefin rubbers, such as ethylene -propylene rubbers (EPDM, EPM); acrylic rubbers; halogen rubbers, such as halogenated butyl rubbers including brominated butyl rubber and chlorinated butyl rubber, brominated isotubylene and poly chloroprene; silicone rubbers, such as methylvinyl silicone rubber and dimethyl silicone rubber; sulfur-containing rubbers, such as polysulfidic rubber; fluorinated rubbers; thermoplastic rubbers, such as elastomers based on styrene, butadiene, isoprene, ethylene and propylene, styrene-isoprene-styrene (SIS), styrene-ethylene-butylene-styrene (SEBS), and styrene-butylene-styrene (SBS); ester-based elastomers; elastomeric polyurethane; and, elastomeric polyamide.

[0139] It is preferred that the rubbers to be treated are characterized by at least one of: a) a Shore A hardness, as determined in accordance with ASTM D2240 of from 10 to 80; b) a Mooney Viscosity, as determined by ASTM D1646 at 125° C of from 5 to 150 ML(l+4); and, c) a melt flow index (MFI) as determined at 190° C and 2.16 kg in accordance with ASTM D1238, of from 1 to 50 dg / min. These characterizations are not mutually exclusive and one, two or three thereof may be applicable.

[0140] Various features and embodiments of the disclosure are described in the following examples, which are intended to be representative and not limiting.

[0141] EXAMPLES

[0142] The following commercial products are employed in the Examples below:

[0143] Dehyquart A CA: Cetyl (Cie) trimethylammonium chloride, cationic surfactant available from BASF. Phy Ion Cleaner: Solvent based liquid cleaning composition, available from Henkel (Loctite Bondace PC3)RB Cleaner: Solvent based liquid cleaning composition, available from Henkel (Loctie Bondace 233M)

[0144] The remaining constituents of the composition described herein below are available from Sigma Aldrich. Example 1

[0145] An aqueous cleaning composition in accordance with the present disclosure (hereinafter AC1) was prepared by mixing the ingredients given in Table 1 herein below.

[0146] Table 1

[0147]

[0148] The aqueous cleaning composition in accordance with Table 1 is a colourless transparent liquid having a pH of 2.3 + / - 0.5.

[0149] Example 2

[0150] The following tests were performed using the aqueous composition (ACL) of Table 1 and, where applicable, the comparative Phylon Cleaner and RB Cleaner.

[0151] Surface Tension (mN / m): KRUSS Easy Drop Shape Analysis was employed to determine the surface tension of the tested compositions. A sessile drop of the composition is metered onto a solid sample: an image of the drop is recorded with the help of a camera and transferred to drop shape analysis software. A contour recognition is initially carried out based on a grey-scale analysis of the image. In a further step, a geometrical model describing the drop shape is fitted to the contour. The contact angle is given by the angle between the calculated drop shape function and the sample surface, the projection of which in the drop image is referred to as the baseline. The surface tension is calculated using a Young-Laplace fit to the contour of a pendant drop determined by image analysis, and based on the image scale and the difference in density between drop phase and bulk solid phase.Surface Energy (Dyne / cm): The tested compositions were independently applied to the substrates documented in Table 2 below and each permitted to dry in ambient air for a duration of 30 minutes. In a reference test, the documented substrates which had not been treated with any cleaning compositions were also evaluated. The surface energies of the substrates were then measured using ARCOTEC™ test inks and test pens available from Lotar Enterprises. As a starting point for each check a test ink or test pen with a medium value should be applied, for example 38 dyne / cm (40 mN / m). If the line of ink stays unchanged for at least 2 seconds on the surface of the material without turning into droplets, the surface energy of the material is the same or higher than the surface tension of the fluid. In this case, the test ink / test pen with the next higher value is applied to the surface, for example 40 dyne / cm (40 mN / m). This check has to be repeated with the next higher value of surface tension up to the point at which, within 2 seconds, the line of applied fluid turns into separate droplets. If already at the starting point (38 mN / m (dyne / cm)) droplets are formed from the line of fluid, the check is continued with test inks / test pens of lower values. As a general limit, 32 dyne / cm may be mentioned: where the surface energy level is below this value, it is considered that subsequent adhesion to the surface will be poor.

[0152] The results of the aforementioned tests are provided in Table 2 below.

[0153] Table 2

[0154]

[0155] Having regard to Table 2, it is noted that the aqueous cleaning composition in accordance with the present disclosure has a comparable surface tension to the organic solvent based cleaning compositions: this demonstrates analogous substrate wetting. Further, the aqueous compositions promoted a significantly higher surface energy than each comparative cleaning treatment and the reference test: it is thereby considered that the documented substrates, when treated with the aqueous cleaning composition, may be more facile to subsequently bond to secondary substrates in the formation of bonded structures.In view of the foregoing description and examples, it will be apparent to those skilled in the art that equivalent modifications thereof can be made without departing from the scope of the claims.

Claims

CLAIMS1. An aqueous cleaning composition comprising:water;a) phosphoric acid;b) at least one cationic surfactant; and,c) at least one water-miscible organic solvent,wherein the aqueous cleaning composition has a pH of from 1 to 5.

2. The aqueous cleaning composition according to claim 1 comprising, based on the weight of the composition:from 10 to 60 wt.% of water;from 0.05 to 2 wt.% of a) said phosphoric acid;from 0.1 to 5 wt.% of b) said at least one cationic surfactant; and,from 20 to 90 wt.% of c) said at least one water-miscible solvent,wherein the aqueous cleaning composition has a pH of from 1 to 4.

3. The aqueous cleaning composition according to claim 1 comprising, based on the weight of the composition:from 10 to 50 wt.%, preferably from 20 to 50 wt.% of water;from 0.05 to 1 wt.%, preferably from 0.1 to 1 wt.% of a) said phosphoric acid;from 0.1 to 1 wt.%, preferably from 0.1 to 0.5 wt.% of b) said at least one cationic surfactant; and, from 40 to 80 wt.%, preferably from 50 to 80 wt.% of c) said at least one water-miscible solvent, wherein the aqueous cleaning composition has a pH of from 1 to 4.

4. The aqueous cleaning composition according to any one of claims 1 to 3, wherein constituent b) comprises or consists of at least one quaternary ammonium compound.

5. The aqueous cleaning composition according to claim 4, wherein said at least one quaternary ammonium compound has the formula (Qa):(Rla)(R2a)(R3a)(R4a)N+X- (Qa)wherein: X" is a counter anion; and,Rlato R4aare the same or different and are independently selected from C1-C20 alkyl, C1-C20 hydroxyalkyl, C1-C20 alkoxyalkyl, C1-C20 alkenyl, Ce-Cis aryl, C7-C18 alkaryl or C7-C18 aralkyl.

6. The aqueous cleaning composition according to claim 5, wherein:X" is selected from the group consisting of halides, sulphate, methyl sulphate, ethyl sulphate and sulphonates; and,Rlato R4aare independently selected from Ci-Cis alkyl, Ci-Cis hydroxyalkyl, Ci-Cis alkoxy or Ci-Cis alkenyl.

7. The aqueous cleaning composition according to claim 6, wherein:X-is halide; and,Rlato R4aare independently selected from Ci-Cis alkyl, Ci-Cis hydroxyalkyl or Ci-Cis alkoxy.

8. The aqueous cleaning composition according to claim 4, wherein said at least one quaternary ammonium compound has the formula (Qb):(Rlb)(R2b)(R3b)(R4b)N+X- (Qb)wherein: X" is a counter anion;Rlband R2bmay together form a saturated, unsaturated or heteroaromatic ring together with the nitrogen atom to which they are bonded; and,R3bto R4bare the same or different and are independently selected from C1-C20 alkyl, C1-C20 hydroxyalkyl, C1-C20 alkoxyalkyl, C1-C20 alkenyl, Ce-Cis aryl, C7-C18 alkaryl or C7-C18 aralkyl.

9. The aqueous cleaning composition according to claim 4, wherein said at least one quaternary ammonium compound has the formula (Qc):(R1C)(R2C)(R3C)(R4C)N+X- (Qc)wherein: X" is selected from halide, sulphate, methyl sulphate, ethyl sulphate or sulphonate.Rlcis C4-C18 alkyl or C4-C18 alkenyl;R2cand R3care independently selected from C1-C4 alkyl; and,R4cis C1-C4 alkyl or C1-C4 hydroxyalkyl.

10. The aqueous cleaning composition according to claim 9, wherein:X" is selected from halide, sulphate, methyl sulphate, ethyl sulphate or sulphonate;Rlcis C4-C18 alkyl or C4-C18 alkenyl;R2Cand R3Care independently selected from C1-C2 alkyl; and,R4cis C1-C2 alkyl or C1-C2 hydroxyalkyl.

11. The aqueous cleaning composition according to claim 9, wherein:X is halide;Rlcis Cs-Cie alkyl or Cs-Cie alkenyl;R2Cand R3Care independently selected from C1-C2 alkyl; and,R4cis Ci -C2 alkyl.

12. The aqueous cleaning composition according to any one of claims 1 to 11, wherein the ratio by weight of water to constituent c) said at least one water-miscible organic solvent is from 20:80 to 50:50, preferably from 30:70 to 50:50.

13. The aqueous cleaning composition according to any one of claims 1 to 12, wherein constituent c) comprises or consists of at least one ketone.

14. The aqueous cleaning composition according to any one of claims 1 to 13, wherein constituent c) comprises or consists of acetone and methyl ethyl ketone.

15. Use of the aqueous cleaning composition as defined in any one claims 1 to 14 in the cleaning of polymeric substrates of footwear.

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