WO2016162067A1

WO2016162067A1 - Aqueous cleaning composition for cleaning and disinfecting hard surfaces

Info

Publication number: WO2016162067A1
Application number: PCT/EP2015/057736
Authority: WO
Inventors: Michael Schmidt; Daniela Richter
Original assignee: Ecolab USA Inc
Current assignee: Ecolab USA Inc
Priority date: 2015-04-09
Filing date: 2015-04-09
Publication date: 2016-10-13
Anticipated expiration: 2017-10-09
Also published as: AU2015390857A1

Abstract

The present invention refers to an aqueous cleaning composition for cleaning and disinfecting hard surfaces, said aqueous cleaning composition comprising or consisting of: a) alkylbenzene sulfonic acid, b) peracid, c) hydrogen peroxide d) optionally stabilizing agent, and e) water. The present invention also provides the use of said aqueous cleaning composition for cleaning and disinfecting hard surfaces, preferably in a CIP cleaning process or in a COP cleaning process, more preferred in a CIP cleaning process, and a method of cleaning and disinfecting hard surfaces, preferably in a CIP cleaning process or in a COP cleaning process, more preferred in a CIP cleaning process, comprising contacting said hard surfaces with said aqueous cleaning composition

Description

Aqueous cleaning composition for cleaning and disinfecting hard surfaces

The present invention relates to an aqueous cleaning composition for cleaning and disinfecting of hard surfaces, for example the cleaning means of a milking robot, said composition comprising a combination of a surfactant and a peracid. The present invention provides the use of low-foaming, surfactant-containing percarboxylic acid agents for cleaning and disinfecting hard surfaces, in particular for CIP and COP disinfection.

Background

Milking of cows on a large scale is almost entirely done with a milking machine. The milking machine draws the milk from the cow's udder by pulsating vacuum, e.g., by attaching a teat cup connected to a vacuum pump and pulsating the vacuum to alternately allow the milk to fill and drain from the area of the udder and teat to simulate hand milking of the cow. The tendency is to minimize the milking time by using high vacuum which can cause irritation or damage to the teat and udder.

The damage to tissue caused by the milking machine followed by exposure of the damaged tissue to certain microorganisms can result in an infection known as mastitis. Control of mastitis is of great economic importance to dairy farmers because an infected cow's contaminated milk cannot be marketed.

According to experts, prevention of mastitis by the dipping of teats in an antimicrobial (biostatic or biocidal) solution is one of the most effective procedures that a dairy farmer can follow. Application of an antimicrobial solution may be performed before or after milking, or both. The treatment is carried out either by dipping the teats in or spraying them with the disinfecting solution. An essential function of such treatment is to prevent mastitis by killing or controlling infectious microorganisms. The respective product desirably has a wide spectrum of antibacterial activity (i.e., it can kill or inhibit the growth of a wide variety of mastitis-causing microorganisms), and has emollient properties to prevent irritation of the skin on which it is applied.

Further, milking robots have been constructed, which carry out all steps including cleaning udder and teats and milking. For example, cleaning of udder and teats is carried out by use of rotating brushes in order to remove soil and manure. This step is carried out before milking. The brushes need to be cleaned and sanitized by spraying a disinfectant on the rotating brushes. As a result of this measure, the bacteria present on the brushes are destroyed within a few minutes, thus reducing the risk of cross contamination.

The use of halogen-releasing substances, halocarboxylic acids such as monobromoacetic acid, oxidative compounds such as chlorine dioxide, peroxyacetic acid, active chlorine and other antimicrobial substances such as isothiazolinones for cleaning and/or disinfecting hard surfaces is known. Furthermore, many antimicrobial agents such as, inter alia, oxidative agents, organic acids, phenyl compounds or guanidines and many other compounds are known.

Depending on the formulation, for example in combination with foaming surfactants, it may be that these types of active substances promote the production of foam in the cleaning solution, which is undesirable, for example, in some fields of application in the beverage producing industry.

In particular in CIP cleaning processes, there is a demand for agents where the foaming characteristics are not a problem during use and with which at the same time particularly good wetting of the surfaces being treated is achieved.

In the following, an explanation is given of what a CIP process is understood to mean in the context of the present invention. CIP is a familiar abbreviation in the specialist field and means Cleaning in Place.

By CIP, a person skilled in the art understands that hard surfaces of items, containers, tanks such as milk tankers or fermentation tanks in breweries are generally automatically treated with cleaning and/or disinfecting agents stored on site via equipment or devices installed on site on or in the item being cleaned, such as, for example, processing tanks, fluid lines, pumps, valves, heat exchangers, piping, pumps, nozzles, containers, spray-heads.

A CIP cleaning process cleans the internal surfaces of these components without the need to dismantle any of the components for individual cleaning. Rather, the components can be cleaned by passing a cleaning solution through the components, for example following a fluid path normally traveled by a fluid processed on the equipment, to clean the components.

Because of its ease of use and effectiveness, CIP cleaning processes have found widespread applicability in many different industries, particularly those industries where hygiene and sterility are of particular importance. Example industries that use CIP cleaning processes include dairy, beverage, brewing, pharmaceuticals, and cosmetics. In these and other industries, internal surfaces of processing equipment can become contaminated with soil during operation. To help ensure the operational efficiency of the processing equipment and to remove soil buildup from production equipment, the processing equipment is periodically cleaned using a CIP process.

Accordingly, CIP cleaning, as understood by a person skilled in the art, is the cleaning and/or disinfection of hard surfaces in a specific process, the CIP process. Due to the turbulent motion of the cleaning and disinfecting solution resulting from pumping, spraying and other processes, agents and solutions which tend to produce foam pose problems when used in a CIP process. Therefore, in a CIP process low foaming products are desired although such products need not necessarily to be completely foam-free.

For this reason, in practice the use of agents which contain highly foaming surfactants such as alkylamine oxides, ethercarboxylic acids, alkylether sulfates, are basically avoided in the context of CIP processes. On the one hand the wetting characteristics of the agent used are of especial importance. Thus, bacterial problems often occur in disinfection processes when, although sufficient active disinfectant is used, this does not reach the surface to be disinfected in CIP disinfection processes or does not adhere to this surface for a sufficiently long time in COP disinfection processes, due to low wetting power.

Further difficulties with regard to wetting are provided in CIP processes by the complexity of the structure to be cleaning and disinfected, which is why structurally restricted areas are present which are difficult to reach with the agent. Complete wetting at the application concentration required, with the maintenance of a minimum contact time, using selected disinfectants, however, is absolutely necessary for reliable destruction of all harmful microorganisms.

Another disadvantage of commonly used aqueous disinfectant solutions for CIP processes is also, due to the poor wetting characteristics, that they are not able to reach into microscopically small gaps, surfaces, scratches and inaccessible edges and corners of areas of the plant made of stainless steel in order also to completely destroy harmful microorganisms here.

However, it is also known that many surfactants, due to their strong wetting effect, exhibit very intense foaming behavior under the conditions of application. Foaming disinfectant solutions cannot be used in the field of CIP plants for disinfecting closed circuits. Intense foam production would impair the technical function of these plants and lead to unwanted operating problems. In contrast, in COP cleaning processes foam production is desired.

Presently, the application of cleaning and disinfecting products is covered with different peroxyacetic acid based products, which either comprise one or several surfactants or no surfactants. These products have a fairly weak foam appearance at the desired concentration of the use solution.

As the foam appearance is a visible indicator of the presence relating to the time- period and coverage over area of product applied to the surface to be cleaned, it was the technical object of the present invention to improve the foam properties for COP application and the microbiological performance while providing a product which can be diluted and prepared in a CIP process of the respective products.

A further object of the present invention was to provide a peracid compostion which achieve a very good disinfectant result when used for disinfection in CIP processes, for example cleaning of tanks, lines, pumps and other process equipment used for processing typically liquid product streams of beverages, in particular for cleaning milking machines, and at the same time have a positive effect on the wetting properties without having foam characteristics which might cause problems in a CIP process being observed.

A still further object of the present invention was to provide agents which achieve a very good disinfectant result when used for both disinfection in CIP and disinfection in COP processes, having a positive effect on the wetting properties in order to reach the surface to be disinfected in CIP disinfection processes and to adhere to this surface for a sufficiently long time in COP disinfection processes. Therefore, the object of the invention was also to provide improved peracid compositions for COP applications, for example cleaning the interior and exterior surfaces of a wide variety of parts, such as cleaning brushes, ceramic surfaces, metal surfaces, walls in, wash tanks, soaking vessels, mop buckets, holding tanks, scrub sinks, vehicle parts washers, non-continuous batch washers and systems, and the like.

Summary of the invention

The technical object is solved by an aqueous cleaning composition for cleaning and disinfecting hard surfaces, in particular in a CIP process and/or for cleaning and disinfecting the cleaning means for cleaning teats and udder, preferably rotating brushes, of a milking robot, comprising or consisting of:

a) alkylbenzene sulfonic acid,

b) peracid,

c) hydrogen peroxide,

d) optionally stabilizing agent, and

e) water. The aqueous cleaning composition for cleaning and disinfecting hard surfaces described refers to the concentrate as well as to the use solution made therefrom.

In a preferred embodiment of the present invention the alkylbenzene sulfonic acid is C9-18 alkylbenzene sulfonic acid, further preferred C-io-i e alkylbenzene sulfonic acid, more preferred C-10-13 alkylbenzene sulfonic acid. Further preferred, the alkylbenzene sulfonic acid is linear alkylbenzene sulfonic acid, more preferably linear do-13 alkylbenzene sulfonic acid. In a particular preferred embodiment the alkylbenzene sulfonic acid is linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13. In another particular preferred embodiment the alkylbenzene sulfonic acid is linear straight chain alkylbenzene sulfonic acid in which at least 95 wt.-% of the alkylbenzene sulfonic acid has 10 to 13 carbon atoms in the alkyl group. A preferred alkylbenzene sulfonic acid is commercially available as MARLON® AS 3 (Sasol Germany GmbH, Marl, Germany).

In another preferred embodiment the composition of the present invention further comprises stabilizing agents.

In a further particularly preferred embodiment the peracid is selected from:

a) peracids corresponding to general formula (I) R¹-O₂C-(CH₂)p-CO₃H, wherein R¹ is hydrogen or an alkyl group containing 1 to 4 carbon atoms and p is an integer from 1 to 4, or salts thereof;

b) phthalimidopercarboxylic acids (II) wherein the percarboxylic acid contains 1 to 18 carbon atoms, or salts thereof;

c) compounds corresponding to formula (III) R²-CO₃H, wherein R² is an alkyl or alkenyl group containing 1 to 22, preferably 1 to 18 carbon atoms.

Still further preferred the peracid is selected from:

a) peracids corresponding to general formula (I) R¹-O₂C-(CH₂)p-CO₃H, wherein R¹ is hydrogen or methyl group and p is an integer from 1 to 4, or salts thereof; b) phthalimidopercarboxylic acids (II) wherein the percarboxylic acid contains 1 to 8 carbon atoms, or salts thereof;

c) compounds corresponding to formula (III) R²-C0₃H, wherein R² is an alkyl or alkenyl group containing 1 to 12 carbon atoms.

In a further particularly preferred embodiment of the present invention the peracid (or peroxycarboxylic acid) is selected from peracetic acid, perpropionic acid, peroctanoic acid, phthalimidoperhexanoic acid, phthalimidoperoctanoic acid, persuccinic acid, persuccinic acid monomethyl ester, perglutaric acid, perglutaric acid monomethyl ester, peradipic acid, peradipic acid monomethyl ester, persuccinic acid, and persuccinic acid monomethyl ester. Peracetic (or peroxyacetic) acid is most preferred.

In another preferred embodiment the composition comprises 0.01 to 15.0 wt.-% of alkylbenzene sulfonic acid, 0.01 to 30.0 wt.-% of peracid and 0.01 to 50.0 wt.-% of hydrogen peroxide and 0.000 to 2.0 wt.-%, preferably 0.001 to 2.0 wt.-% stabilizing agent.

The artisan understands that the peracid is present in an equilibrium reaction mixture with hydrogen peroxide and the corresponding acid, i.e. the peracid exists as chemical equilibrium consisting of the peracid, the corresponding carboxylic acid, hydrogen peroxide and water. In particular, the peracid is peroxyacetic acid and present in an equilibrium reaction mixture with hydrogen peroxide, acetic acid and water. Therefore, the aqueous cleaning composition may include in addition to the peracid, in particular in addition to the 0.01 wt.-% to 30.0 wt.-% of peracid the corresponding carboxylic acid in an amount from 0.000 wt.-% to 60.0 wt.-%, which also applies to the respective preferred embodiments mentioned hereinafter. Further, if in the aqueous cleaning composition any other peracid as described herein is used, the aqueous cleaning composition may include in addition to the respective peracid, in particular in addition to the 0.01 wt.-% to 30.0 wt.-% of peracid the corresponding carboxylic acid in an amount from 0.000 wt.-% to 60.0 wt.-%, which also applies to the respective preferred embodiments mentioned hereinafter. Moreover, if in the aqueous cleaning composition peroxyacetic acid is used, the aqueous cleaning composition may include in addition to the peroxyacetic acid, in particular in addition to the 0.01 wt.-% to 30.0 wt.-% of peroxyacetic acid the corresponding acetic acid in an amount from 0.000 wt.-% to 60.0 wt.-%, which also applies to the respective preferred embodiments mentioned hereinafter.

In a preferred embodiment of the present invention the aqueous composition for cleaning and disinfecting hard surfaces comprises or consists of:

a) 0.01 to 15.0 wt.-% of alkylbenzene sulfonic acid,

b) 0.01 to 30.0 wt.-% of peracid,

c) 0.01 to 50.0 wt.-% of hydrogen peroxide,

d) 0.000 to 2.0 wt.-% of a stabilizing agent, and

e) adding up to 100 wt.-% with water.

In a further preferred embodiment of the present invention the aqueous composition for cleaning and disinfecting hard surfaces comprises or consists of:

a) alkylbenzene sulfonic acid, preferably C₉-i₈ alkylbenzene sulfonic acid, further preferred C-io-ie alkylbenzene sulfonic acid, more preferred C-io-₁₃ alkylbenzene sulfonic acid; still further preferred linear alkylbenzene sulfonic acid, more preferably linear do-₁₃ alkylbenzene sulfonic acid; in particular linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13; b) peroxyacetic acid, and

c) hydrogen peroxide,

d) optionally stabilizing agent, and

e) adding up to 100 wt.-% with water.

In a further preferred embodiment of the present invention the aqueous composition for cleaning and disinfecting hard surfaces comprises:

a) 0.01 to 15.0 wt.-% of alkylbenzene sulfonic acid, preferably C₉-i₈

alkylbenzene sulfonic acid, further preferred C-io-ie alkylbenzene sulfonic acid, more preferred C-io-₁₃ alkylbenzene sulfonic acid; still further preferred linear alkylbenzene sulfonic acid, more preferably linear C-₁₀-₁₃ alkylbenzene sulfonic acid; in particular linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13;

0.01 to 30.0 wt.-% of peroxyacetic acid, and

0.01 to 50.0 wt.-% of hydrogen peroxide.

optionally stabilizing agent, and

adding up to 100 wt.-% with water.

In yet another preferred embodiment of the present invention the aqueous

composition for cleaning and disinfecting hard surfaces comprises or consists of: a) 0.01 to 15.0 wt.-% of C-|₀-C-|₃ alkylbenzene sulfonic acid,

b) 0.01 to 30.0 wt.-% of peroxyacetic acid,

c) 0.01 to 50.0 wt.-% of hydrogen peroxide,

d) 0.000 to 2.0 wt.-% of a stabilizing agent, preferably 1 - hydroxyethylidene-1 ,1 -diphosphonic acid, and

e) adding up to 100 wt.-% with water.

As outlined above, in a preferred embodiment of the present invention the aqueous cleaning composition comprises or consists of:

- a peracid (or percarboxylic acid), in particular peroxyacetic acid, which is combined with the corresponding carboxylic acid, in particular acetic acid, and hydrogen peroxide in an equilibrium reaction mixture;

- alkylbenzene sulfonic acid, preferably C₉-i₈ alkylbenzene sulfonic acid, further preferred C-io-ie alkylbenzene sulfonic acid, more preferred C-10-13 alkylbenzene sulfonic acid. Further preferred, the alkylbenzene sulfonic acid is linear alkylbenzene sulfonic acid, more preferably linear do-₁₃ alkylbenzene sulfonic acid. In a particular preferred embodiment the alkylbenzene sulfonic acid is linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13. In another particular preferred embodiment the alkylbenzene sulfonic acid is linear straight chain alkylbenzene sulfonic acid in which at least 95 wt.-% of the alkylbenzene sulfonic acid has 10 to 13 carbon atoms in the alkyl group. A preferred alkylbenzene sulfonic acid is commercially available as MARLON® AS 3 (Sasol Germany GmbH, Marl, Germany); - optionally a stabilizing agent, and

- water.

Use solution

The present invention also provides a use solution of the composition according to the present invention, comprising or consisting of:

a) 0.005 to 0.1 wt.-% of alkylbenzene sulfonic acid,

b) 0.005 to 0.2 wt.-% of peracid, and

c) 0.005 to 0.3 wt.-% of hydrogen peroxide

d) 0.000 to 0.01 wt.-% of a stabilizing agent, and

e) adding up to 100 wt.-% with water.

As described above, the artisan understands that the peracid is present in an equilibrium reaction mixture with hydrogen peroxide and the corresponding acid, i.e. the peracid exists as chemical equilibrium consisting of the peracid, the corresponding carboxylic acid, hydrogen peroxide and water. In particular, the peracid is peroxyacetic acid and present in an equilibrium reaction mixture with hydrogen peroxide, acetic acid and water. Therefore, the use solution of the aqueous cleaning composition may include in addition to the peracid, in particular in addition to the 0.005 wt.-% to 0.2 wt.-% of peracid the corresponding carboxylic acid in an amount from 0.000 wt.-% to 0.4 wt.-%, which also applies to the respective preferred embodiments mentioned hereinafter. Further, if in the use solution of the aqueous cleaning composition any other peracid as described herein is used, the use solution of the aqueous cleaning composition may include in addition to the respective peracid, in particular in addition to the 0.005 wt.-% to 0.2 wt.-% of peracid the corresponding carboxylic acid in an amount from 0.000 wt.-% to 0.4 wt.-%, which also applies to the respective preferred embodiments mentioned hereinafter. Moreover, if in the use solution of the aqueous cleaning composition peroxyacetic acid is used, the use solution of the aqueous cleaning composition may include in addition to the peroxyacetic acid, in particular in addition to the 0.005 wt.-% to 0.2 wt.-% of peroxyacetic acid the corresponding acetic acid in an amount from 0.000 wt.-% to 0.4 wt.-%, which also applies to the respective preferred embodiments mentioned hereinafter.

In a further preferred embodiment the use solution comprises or consists of

a) 0.005 to 0.1 wt.-% of alkylbenzene sulfonic acid, preferably C₉-i₈ alkylbenzene sulfonic acid, further preferred C-io-ie alkylbenzene sulfonic acid, more preferred C-10-13 alkylbenzene sulfonic acid; still further preferred linear alkylbenzene sulfonic acid, more preferably linear do-13 alkylbenzene sulfonic acid; in particular linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13;

b) 0.005 to 0.2 wt.-% of peracid, and

c) 0.005 to 0.3 wt.-% of hydrogen peroxide,

d) 0.000 to 0.01 wt.-% of a stabilizing agent, and

e) adding up to 100 wt.-% with water.

In a preferred embodiment the use solution comprises or consists of:

a) 0.005 to 0.1 wt.-% of alkylbenzene sulfonic acid, preferably C₉-i₈ alkylbenzene sulfonic acid, further preferred C-io-ie alkylbenzene sulfonic acid, more preferred C-10-13 alkylbenzene sulfonic acid; still further preferred linear alkylbenzene sulfonic acid, more preferably linear C-10-13 alkylbenzene sulfonic acid; in particular linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13;

b) 0.005 to 0.2 wt.-% of peroxyacetic acid,

c) 0.005 to 0.3 wt.-% of hydrogen peroxide,

d) 0.000 to 0.01 wt.-% of a stabilizing agent, and

e) adding up to 100 wt.-% with water.

In yet another preferred embodiment the use solution comprises or consists of:

a) 0.005 to 0.1 wt.-% of alkylbenzene sulfonic acid, preferably Cg.-is

alkylbenzene sulfonic acid, further preferred C-io-i e alkylbenzene sulfonic acid, more preferred C-10-13 alkylbenzene sulfonic acid; still further preferred linear alkylbenzene sulfonic acid, more preferably linear C10-13 alkylbenzene sulfonic acid; in particular linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13;

b) 0.005 to 0.2 wt.-% of peroxyacetic acid,

c) 0.005 to 0.3 wt.-% of hydrogen peroxide,

d) 0.000 to 0.01 wt.-% of a stabilizing agent, preferably 1 - hydroxyethylidene-1 ,1 -diphosphonic acid, and

e) adding up to 100 wt.-% with water.

In yet another preferred embodiment the use solution comprises or consists of:

a) 0.005 to 0.1 wt.-% of C-|₀-C-|₃ alkylbenzene sulfonic acid,

b) 0.005 to 0.2 wt.-% of peroxyacetic acid,

c) 0.005 to 0.3 wt.-% of hydrogen peroxide,

e) adding up to 100 wt.-% with water.

The present invention further provides the use of the above described aqueous cleaning composition for cleaning and disinfecting hard surfaces, preferably in a CI P cleaning process or in a COP cleaning process, more preferred in a CI P cleaning process.

In a preferred use the hard surfaces are represented by the cleaning means for cleaning teats and udder of a milking robot. In a still further preferred use the hard surfaces are represented by the brushes for cleaning teats and udder of a milking robot.

The present invention also provides a method of cleaning and disinfecting hard surfaces, preferably in a CI P cleaning process or in a COP cleaning process, more preferred in a CI P cleaning process, comprising contacting said hard surfaces with the above described aqueous cleaning composition.

In a preferred method according to the present invention the hard surfaces are represented by the cleaning means for cleaning teats and udder of a milking robot. Still further preferred the hard surfaces are represented by the brushes for cleaning teats and udder of a milking robot.

The aqueous cleaning composition for cleaning and disinfecting may be applied to the hard surfaces by spray application or foam application.

The number of cleaning steps performed during the cleaning method can vary depending on the specific process being performed. At minimum, the aqueous cleaning composition solution is applied to the hard surface to be cleaned. More typically, the cleaning method involves at least three steps. In the first step, which may be referred to as a pre-rinse step, a fluid such as fresh water is applied to the hard surface in order to rinse the hard surface of soil (e.g., soil on the cleaning means of the milking robot). In the second step, which may be referred to as a cleaning step, the aqueous cleaning composition of the present invention is applied as use solution to the hard surface to clean and disinfect the hard surface. Finally, in the third step, a rinse liquid such as fresh water is applied to the hard surface to rinse any residual cleaning composition from the hard surface.

Therefore, in a particularly preferred embodiment the method comprises the following steps:

a) rinsing the hard surface, preferably the brushes for cleaning teats and udder of a milking robot, with water to rinse the hard surface of soil;

b) applying the aqueous cleaning composition of the present invention as described above to the hard surface to clean and disinfect the hard surface, wherein the applied aqueous cleaning composition preferably is a use solution;

c) rinsing the hard surface with water to rinse any residual cleaning composition from the hard surface.

Detailed description of the invention

The present invention provides an aqueous cleaning composition for cleaning and disinfecting hard surfaces, in particular the cleaning means for cleaning teats and udder, preferably rotating brushes, of a milking robot, comprising or consisting of: a) alkylbenzene sulfonic acid,

b) peracid, and optionally the corresponding carboxylic acid,

c) hydrogen peroxide

d) optionally stabilizing agent, and

e) water.

Accordingly, this invention contemplates an aqueous cleaning and disinfecting composition suitable for the killing of mastitis which comprises alkylbenzene sulfonic acid, peracid, hydrogen peroxide, optionally a stabilizing agent, and water. The composition of the invention is provided as a concentrate that is later diluted with water. As a result, the compositions can be used on a variety of hard surfaces.

The embodiments of this invention are not limited to particular compositions, methods of use and methods of making, which can vary and are understood by skilled artisans. It is further to be understood that all terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting in any manner or scope. For example, as used in this specification and the appended claims, the singular forms "a," "an" and "the" can include plural referents unless the content clearly indicates otherwise.

The term "consisting of" or "consists of", as far as used herein in respect to peracids, peroxyacids or peroxycarboxylic acids always include the corresponding carboxylic acid, although the latter may not necessarily be mentioned. The artisan understands that the peracid is present in an equilibrium reaction mixture with hydrogen peroxide, and the corresponding acid, i.e. the peracid exists as chemical equilibrium consisting of the peracid, the corresponding carboxylic acid, hydrogen peroxide and water. In particular, the peracid is peroxyacetic acid and present in an equilibrium reaction mixture with hydrogen peroxide, acetic acid and water.

So that the present invention may be more readily understood, certain terms are first defined. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the invention pertain. Many methods and materials similar, modified, or equivalent to those described herein can be used in the practice of the embodiments of the present invention without undue experimentation, the preferred materials and methods are described herein. In describing and claiming the embodiments of the present invention, the following terminology will be used in accordance with the definitions set out below.

The term "alkyl" or "alkyl groups," as used herein, refers to saturated hydrocarbons having one or more carbon atoms, including straight-chain alkyl groups (e.g. , methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc.), cyclic alkyl groups (or "cycloalkyl" or "alicyclic" or "carbocyclic" groups) (e.g. cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc.), branched- chain alkyl groups (e.g. isopropyl, tert-butyl, sec-butyl, isobutyl, etc.), and alkyl- substituted alkyl groups (e.g. alkyl- substituted cycloalkyl groups and cycloalkyl- substituted alkyl groups). Unless otherwise specified, the term "alkyl" includes both "unsubstituted alkyls" and "substituted alkyls." As used herein, the term "substituted alkyls" refers to alkyl groups having substituents replacing one or more hydrogens on one or more carbons of the hydrocarbon backbone. Such substituents may include, for example, alkenyl, alkynyl, halogeno, hydroxyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy, aryloxy, aryloxycarbonyloxy, carboxylate, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, alkylthiocarbonyl, alkoxyl, phosphate, phosphonato, phosphinato, cyano, amino (including alkyl amino, dialkylamino, arylamino, diarylamino, and alkylarylamino), acylamino (including alkylcarbonylamino, arylcarbonylamino, carbamoyl and ureido), imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate, sulfates, alkylsulfinyl, sulfonates, sulfamoyl, sulfonamido, nitro, trifluoromethyl, cyano, azido, heterocyclic, alkylaryl, or aromatic (including heteroaromatic) groups.

Differentiation of antimicrobial "-cidal" or "-static" activity, the definitions which describe the degree of efficacy, and the official laboratory protocols for measuring this efficacy are considerations for understanding the relevance of antimicrobial agents and compositions. Antimicrobial compositions can affect two kinds of microbial cell damage. The first is a lethal, irreversible action resulting in complete microbial cell destruction or incapacitation. The second type of cell damage is reversible, such that if the organism is rendered free of the agent, it can again multiply. The former is termed bacteriocidal and the later, bacteriostatic. A sanitizer and a disinfectant are, by definition, agents which provide antibacterial or bacteriocidal activity. In contrast, a preservative is generally described as an inhibitor or bacteriostatic composition.

For the purpose of this patent application, successful reduction of microorganisms is achieved when the populations of microorganisms are reduced by about 50%, by significantly more than is achieved by a wash with water, or at least about 0.3-1 log . Larger reductions in microbial population provide greater levels of protection. In this application, such a population reduction is the minimum acceptable for the processes. Any increased reduction in population of microorganisms is an added benefit that provides higher levels of protection. More preferred the aqueous cleaning composition provides at least a 3-log ₀, further preferred at least a 4-log-i₀ and even further preferred a 5-log-io reduction.

The term "disinfectant", as used herein, refers to an agent that kills all vegetative cells including most recognized pathogenic microorganisms. The term "sanitizer", as used herein, refers to an agent that reduces the number of bacterial contaminants to safe levels as judged by public health requirements. In a preferred embodiment, disinfectants or sanitizers - the aqueous cleaning composition for cleaning and disinfection - for use in this invention will provide at least a 99.9% reduction (3-log order reduction), preferably a 99.99% reduction (4-log order reduction) or more preferred a 99.999% reduction (5-log order reduction). These reductions can be evaluated using procedures set out according to the standards as described below. The term ..disinfectant" or ..sanitizer", as used herein, refers to an agent which meets the European requirements according to the Biocidals Products Regulation No 528/2012. According to this regulation the respective product must meet the following standards in food industry and agriculture, respectively.

Food industry:

According to standard EN 1276 clean conditions are defined, if the product achieves at least a 5-log reduction of bacterial cells within 5 min contact time at 20 °C. According to standard EN 1650 clean conditions are defined, if the product achieves at least a 4-log reduction of fungal cells within 5 min contact time at 20 °C.

According to standard EN 13697 clean conditions are defined, if the product achieves at least a 4-log reduction of bacterial cells within 5 min contact time at 20 °C and at least a 3-log reduction of fungal cells within 15 min contact time at 20 °C.

Agriculture:

According to standard EN 1656 clean conditions are defined, if the product achieves at least a 5-log reduction of bacterial cells within 30 min contact time at 10°C.

According to standard EN 1657 clean conditions are defined, if the product achieves at least a 4-log reduction of fungal cells within 30 min contact time at 10°C.

According to standard EN 14349 clean conditions are defined, if the product achieves at least a 4-log reduction of bacterial cells within 30 min contact time at 10°C.

The EN standards mentioned above represent the minimum requirements in order to achieve the approval as disinfectant or sanitizer. Therefore these EN standards represent mandatory conditions which the aqueous composition of the present invention meets. Beyond these mandatory and minimum conditions it is possible to test the product in respect to different conditions using different contact times, different temperatures and different soiling.

The term "microorganisms," as used herein, refers to any noncellular or unicellular (including colonial) organism. Microorganisms include all prokaryotes. Microorganisms include bacteria (including cyanobacteria), lichens, microfungi (fungal cells), protozoa, virions, viroids, viruses, and some algae. As used herein, the term "microbe" is synonymous with microorganism.

The terms "mixed" or "mixture" when used relating to "peracid composition," "peroxycarboxylic acid composition," "peracids" or "peroxycarboxylic acids" refer to a composition or mixture including more than one peracid or peroxycarboxylic acid, such as a composition or mixture including peroxyacetic acid and peroxyoctanoic acid.

The term "weight percent," "wt.-%," "percent by weight," "% by weight," and variations thereof, as used herein, refer to the concentration of a substance as the weight of that substance divided by the total weight of the composition and multiplied by 100. It is understood that, as used here, "percent," "%" and the like are intended to be synonymous with "weight percent," "wt.-%," etc.

The methods and compositions of the present invention may comprise, consist essentially of, or consist of the component and ingredients of the present invention as well as other ingredients described herein. As used herein, "consisting essentially of means that the methods and compositions may include additional steps, components or ingredients, but only if the additional steps, components or ingredients do not materially alter the basic and novel characteristics of the claimed methods and compositions.

In a preferred embodiment the stabilizing agent is selected from hydroxyethylidene- 1 ,1 -diphosphonic acid (HEDP), methylglycinediacetic acid (MGDA), tetrasodium N,N- bis(carboxylatomethyl)-L-glutamate (GLDA), dipicolinic acid, ethylene diamine tetraacetic acid (EDTA), nitrilotriacetic acid (NTA), iminodisuccinic acid (IDS) and other phosphonic acids. In a particularly preferred embodiment the stabilizing agent is 1 -hydroxyethylidene-1 ,1 -diphosphonic acid or dipicolinic acid.

The present inventors surprisingly found that an aqueous cleaning composition combining alkylbenzene sulfonic acid and peroxycarboxylic acid shows a synergistic effect with regards to the peracid generation compared to compositions making use of surfactants of the same or other chemical classes and to the properties of the foam.

In the control of bovine mastitis and rapid killing of bacteria is essential, since prolonged treatment (e.g. more than 15 minutes or even more than a minute) is normally impractical. The method and composition of the present invention do provide this desirable rapid kill. The antimicrobial activity (e.g., biostatic and biocidal activity) against both gram positive and gram negative microorganisms (e.g., mastitis) of an aqueous anionic surfactant is significantly increased when the aqueous mixture has therein a peroxycarboxylic acid. The aqueous cleaning composition has been found to have optimum antimicrobial activity (and hence optimum mastitis inhibition).

Typically, the pH of the compositions of the invention is less than 1 or 2, and the pH of a 1 % or 0.5% solution in water is 2.0 to 6.5. The compositions of the present invention preferably are maintained at a pH in the range of 0.8 to 5.0, further preferred in the range of 1 .0 to 4.5 and most preferably in the range of 1 .0 to 3.5. The concentrates of the aqueous cleaning composition of the invention are maintained at a pH in the range of 0.8 to 2.0, preferably in the range of 0.8 to 1 .5 and most preferably in the range of 0.8 to 1 .2. The use solutions, preferably a 0.5 % use solution, of the aqueous cleaning composition concentrate of the invention are maintained at a pH in the range of 2.0 to 4.0, preferably in the range of 2.5 to 3.5 and most preferably in the range of 2.7 to 3.3.

Aqueous cleaning compositions according to the present invention, according to available test results, have excellent bactericidal properties against gram negative organisms such as Pseudomonas aeruginosa, Escherichia coli (E. coli), Enterobacter aerogenes, and gram positive bacteria such as Staphylococcus aureus appear to provide relative quick bactericidal action, preferably a 5-log reduction or more.

The aqueous cleaning composition according to the present invention is used for cleaning and disinfecting hard surfaces, in particular the cleaning means for cleaning teats and udder with brushes of a milking robot. In particular, the teats or udder are cleaned by means of rotating brushes of a milking robot in order to remove soil and manure from the teats and udder. This step is carried out before milking. The brushes themselves need to be cleaned and sanitized by spraying a disinfectant on the rotating brushes. The application of spaying products on the cleaning brushes is a very specific application in terms of the requirements for the foam profile. The application solution will be prepared in a tank or dose-in line which requires a low or non foaming profile. Afterwards the product will be sprayed on the brushes, wherein foaming properties are required to increase the contact time on the brush. Therefore, a foam profile is required which is a combination of low foaming CIP (cleaning-in- place) and stronger foaming COP (cleaning-out-of-place). The advantage of the combination by using alkylbenzene sulfonic acid in combination with peracids is the fact that depending on the use quantities an optimized foam profile can be achieved to fulfil these special requirements.

In particular, the present invention provides an aqueous cleaning composition for cleaning and disinfecting hard surfaces, in particular the cleaning means for cleaning teats and udder, preferably rotating brushes, of a milking robot, comprising or consisting of:

- alkylbenzene sulfonic acid, preferably C9-18 alkylbenzene sulfonic acid, further preferred C-10-16 alkylbenzene sulfonic acid, more preferred C-io-13 alkylbenzene sulfonic acid. Further preferred, the alkylbenzene sulfonic acid is linear alkylbenzene sulfonic acid, more preferably linear do-13 alkylbenzene sulfonic acid. In a particular preferred embodiment the alkylbenzene sulfonic acid is linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13. In another particular preferred embodiment the alkylbenzene sulfonic acid is linear straight chain alkylbenzene sulfonic acid in which at least 95 wt.-% of the alkylbenzene sulfonic acid has 10 to 13 carbon atoms in the alkyl group. A preferred alkylbenzene sulfonic acid is commercially available as MARLON® AS 3 (Sasol Germany GmbH, Marl, Germany);

- optionally a stabilizing agent, and

- water.

According to the invention the aqueous cleaning composition comprises alkylbenzene sulfonic acid, preferably C₉-i₈ alkylbenzene sulfonic acid, further preferred C10-16 alkylbenzene sulfonic acid, more preferred C-10-13 alkylbenzene sulfonic acid, further preferred linear alkylbenzene sulfonic acid, still further preferred C-io-13 alkylbenzene sulfonic acid. In a particular preferred embodiment the alkylbenzene sulfonic acid is linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13. In another particular preferred embodiment the alkylbenzene sulfonic acid is linear straight chain alkylbenzene sulfonic acid in which at least 95 wt.-% of the alkylbenzene sulfonic acid has 10 to 13 carbon atoms in the alkyl group. A preferred alkylbenzene sulfonic acid is commercially available as MARLON® AS 3 (Sasol Germany GmbH, Marl, Germany).

Linear alkylbenzene sulfonates, or linear alkylbenzene sulfonic acids, (hereafter sometimes collectively referred to as "LAS") are moderately effective bactericides, particularly in mildly acidic media. However, linear alkylbenzene sulfonic acids are generally more active against gram positive organisms such as Staphylococcus aureus than against gram negative organisms, particularly at "skin" pH, i.e., greater than 5.0. These microorganisms may have as their origin, water, soil, improperly cleaned utensils, manure, infected cows, human hands, etc. For the most part, gram positive organisms such as Staphylococcus aureus originate in mammals (including humans), while many gram negative organisms are found in the feces of animals as well as humans. "Gram positive" and "gram negative" are designations of bacteria which are well-known to one skilled in the art. Linear alkylbenzene sulfonates are a useful class of anionic surfactants which appear to provide activity against both gram positive microorganisms (e.g., S. aureus) as well as gram negative microorganisms (e.g., Pseudomonas aeruginosa). While the LAS is not necessary to provide acceptable biocidal results in the aqueous cleaning composition of the invention, it does assist in keeping the aqueous cleaning composition and the use solution in a single phase and provides ideal foam properties. With respect to the linear alkyl chain of the LAS, it should not be so long as to create incompatibility with water yet not so short so as to reduce antimicrobial action. Therefore, the alkyl chains should preferably be 9 to 18, preferably 10 to 16, more preferably 10 to 13 carbon atoms in length. Carboxylic and Percarboxylic Acids

The aqueous cleaning composition according to the present invention also comprises a peracid, also referred to as peroxycarboxylic acid, which exists as chemical equilibrium consisting of a peracid, the corresponding carboxylic acid, hydrogen peroxide and water.

Generally when the peroxycarboxylic acid is formulated in accordance with the invention a mono carboxylic acid, such as acetic acid, is combined with an oxidizer such as hydrogen peroxide. The result of this combination is a reaction producing a peroxycarboxylic acid, such as peroxyacetic acid, and water. The reaction follows an equilibrium in accordance with the following equation:

H₂0₂ +RCOOH ^=^= RCOOOH+H₂O

wherein the K_eq is 2.0.

The importance of the equilibrium stems from the presence of hydrogen peroxide, the carboxylic acid and the peroxycarboxylic acid in the same composition at the same time. This combination provides enhanced sanitizing compared to carboxylic acid alone.

The first constituent of the equilibrium mixture comprises one or more carboxylic acids. The carboxylic acids function as a precursor for the reaction product peroxycarboxylic acid while providing a source of acidity and antimicrobial efficacy. The acidity stabilizes and otherwise assists in maintaining the equilibrium concentration of the peroxycarboxylic acid.

The other principle component of the antimicrobial composition of the invention is an oxidized carboxylic acid. This oxidized or peroxycarboxylic acid provides heightened antimicrobial efficacy when combined with hydrogen peroxide and the monocarboxylic acid in an equilibrium reaction mixture. Generally, any number of peroxycarboxylic acids is useful in accordance with the method of the invention. The peracid is present at an amount sufficient to exhibit antimicrobial activity. A variety of peroxycarboxylic acids may be employed in the compositions according to the invention. According to a preferred embodiment of the invention suitable peroxycarboxylic acids include ester peroxycarboxylic acids, alkyl ester peroxycarboxylic acids, and/or combinations of several different peroxycarboxylic acids, as described herein.

The aqueous cleaning composition according to the present invention includes at least one percarboxylic acid. In some embodiments, the compositions of the present invention include at least two or more percarboxylic acids.

In a preferred embodiment of the system of the present invention the composition comprises a peracid selected from:

a) peracids corresponding to general formula (I) R¹-0₂C-(CH₂)p-C0₃H, wherein R¹ is hydrogen or an alkyl group containing 1 to 4 carbon atoms and p is an integer from 1 to 4, or salts thereof;

c) compounds corresponding to formula (III) R²-C0₃H, wherein R² is an alkyl or alkenyl group containing 1 to 22, preferably 1 to 18 carbon atoms.

In yet a further preferred embodiment of the system the composition comprises a peracid selected from:

a) peracids corresponding to general formula (I) R¹-0₂C-(CH₂)p-C0₃H, wherein R¹ is hydrogen or methyl group and p is an integer from 1 to 4, or salts thereof;

b) phthalimidopercarboxylic acids (II) wherein the percarboxylic acid contains 1 to 8 carbon atoms, or salts thereof;

Further preferred, the peracid is selected from peracetic acid, perpropionic acid, peroctanoic acid, phthalimidoperhexanoic acid, phthalimidoperoctanoic acid, persuccinic acid, persuccinic acid monomethyl ester, perglutaric acid, perglutaric acid monomethyl ester, peradipic acid, peradipic acid monomethyl ester, persuccinic acid, and persuccinic acid monomethyl ester.

In still further preferred embodiments, the carboxylic acid for use with the compositions of the present invention in order to provide the corresponding peroxycarboxylic acid includes a Ci to C₂₂ carboxylic acid. In an aspect, any suitable C₁-C₂₂ carboxylic acid can be used in the present compositions. In some embodiments, the C1-C22 carboxylic acid is a C₂-C₂o carboxylic acid. In other embodiments, the C1-C22 carboxylic is a C-i, C₂, C₃, C₄, C₅, C₆, C₇, C₈, C₉, C-|₀, d-i , C-12, C-13, Ci₄, Ci5, C-I 6, Ci₇, C18, Ci9, C₂o, C21 , or C22 carboxylic acid. Further preferred the carboxylic acid for use with the compositions of the present invention is a Ci to C18 more preferred a Ci to d₂ carboxylic acid. The carboxylic acid for use with the compositions of the present invention in particular may be a C₅ to C-|₂ carboxylic acid. In particular preferred embodiments, the carboxylic acid for use with the compositions of the present invention is a Ci to C₄ carboxylic acid. Examples of suitable carboxylic acids include, but are not limited to, formic, acetic, propionic, butanoic, pentanoic, hexanoic, heptanoic, octanoic, nonanoic, decanoic, undecanoic, dodecanoic, as well as their branched chain isomers, lactic, maleic, ascorbic, citric, hydroxyacetic, neopentanoic, neoheptanoic, neodecanoic, oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, sebacid acid, and mixtures thereof. A particularly preferred carboxylic acid is acetic acid. The compositions may utilize a combination of several different carboxylic acids. In some preferred embodiments, the composition includes one or more Ci to C₄ carboxylic acids and one or more C₅ to C-₁₂ carboxylic acids. In further preferred embodiments, the Ci to C₄ carboxylic acid is acetic acid and the C₅ to C₁₂ acid is octanoic acid.

Corresponding to the carboxylic acid the aqueous cleaning compositions of the present invention comprises include at least one peroxycarboxylic acid. In preferred embodiments, the peroxycarboxylic acid for use with the compositions of the present invention includes a Ci to C₂₂ peroxycarboxylic acid. In an aspect, any suitable C C₂₂ percarboxylic acid can be used in the present compositions. In some embodiments, the C1-C22 percarboxylic acid is a C₂-C₂o percarboxylic acid. In other embodiments, the C1-C22 percarboxylic is a d , C₂, C₃, C₄, C₅, C₆, C₇, C₈, C₉, do, On , Ci2, Ci3, CM, Ci5, C₁₆, Ci7, C₁₈, Ci9, C₂₀, C21 , or C₂₂ percarboxylic acid. Further preferred the peroxycarboxylic acid for use with the compositions of the present invention is a Ci to ds, more preferred a Ci to C₁₂ peroxycarboxylic acid. The peroxycarboxylic acid for use with the compositions of the present invention in particular may be a C₅ to Ci₂ peroxycarboxylic acid. In particular preferred embodiments, the peroxycarboxylic acid for use with the compositions of the present invention is a Ci to C₄ peroxycarboxylic acid. Peroxycarboxylic acids useful in the compositions include peroxyformic, peroxyacetic, peroxypropionic, peroxybutanoic, peroxypentanoic, peroxyhexanoic, peroxyheptanoic, peroxyoctanoic, peroxynonanoic, peroxydecanoic, peroxyundecanoic, peroxydodecanoic, or the peroxyacids of their branched chain isomers, peroxylactic, peroxymaleic, peroxyascorbic, peroxycitric, peroxyhydroxyacetic, peroxyneopentanoic, peroxyneoheptanoic, peroxyneodecanoic, peroxyoxalic, peroxymalonic, peroxysuccinic, peroxyglutaric, peroxyadipic, peroxypimelic, peroxysuberic, peroxysebacid acid and mixtures thereof. A particularly preferred peroxycarboxylic acid is peroxyacetic acid. The compositions may utilize a combination of several different peroxycarboxylic acids. In some preferred embodiments, the composition includes one or more Ci to C₄ peroxycarboxylic acids and one or more C₅ to C-₁₂ peroxycarboxylic acids. In further preferred embodiments, the Ci to C₄ peroxycarboxylic acid is peroxyacetic acid and the C₅ to C-₁₂ acid is peroxyoctanoic acid.

In preferred embodiments, the compositions include peroxyacetic acid. Peroxyacetic (or peracetic) acid is a peroxycarboxylic acid having the formula: CH₃COOOH. Generally, peroxyacetic acid is a liquid having an acrid odor at higher concentrations and is freely soluble in water, alcohol, ether, and sulfuric acid. Peroxyacetic acid can be prepared through any number of methods known to those of skill in the art including preparation from acetaldehyde and oxygen in the presence of cobalt acetate. A solution of peroxycarboxylic acid can be obtained by combining the corresponding carboxylic acid with hydrogen peroxide. A solution of peroxyacetic acid can be obtained by combining acetic acid with hydrogen peroxide. A 50% solution of peroxyacetic acid can be obtained by combining acetic anhydride, hydrogen peroxide and sulfuric acid. In preferred embodiments, the compositions include peroxyoctanoic acid, peroxynonanoic acid, or peroxyheptanoic acid. In further preferred embodiments, the compositions include peroxyoctanoic acid. Peroxyoctanoic (or peroctanoic) acid is a peroxycarboxylic acid having the formula, for example, of n-peroxyoctanoic acid: CH₃(CH₂)₆COOOH. Peroxyoctanoic acid can be an acid with a straight chain alkyl moiety, an acid with a branched alkyl moiety, or a mixture thereof. Peroxyoctanoic acid can be prepared through any number of methods known to those of skill in the art. A solution of peroxyoctanoic acid can be obtained by combining octanoic acid and hydrogen peroxide and a hydrotrope, solvent or carrier.

Useful peroxycarboxylic acids also include the ester peroxycarboxylic acids described herein and compositions of the present invention including those ester peroxycarboxylic acids. Peroxy forms of carboxylic acids with more than one carboxylate moiety can have one or more of the carboxyl moieties present as peroxycarboxyl moieties. These peroxycarboxylic acids have been found to provide good antimicrobial action with good stability in aqueous mixtures. In a preferred embodiment, the composition of the invention utilizes a combination of several different peroxycarboxylic acids. Examples of suitable alkyl ester carboxylic acids include monomethyl oxalic acid, monomethyl malonic acid, monomethyl succinic acid, monomethyl glutaric acid, monomethyl adipic acid, monomethyl pimelic acid, monomethyl suberic acid, and monomethyl sebacic acid; monoethyl oxalic acid, monoethyl malonic acid, monoethyl succinic acid, monoethyl glutaric acid, monoethyl adipic acid, monoethyl pimelic acid, monoethyl suberic acid, and monoethyl sebacic acid; monopropyl oxalic acid, monopropyl malonic acid, monopropyl succinic acid, monopropyl glutaric acid, monopropyl adipic acid, monopropyl pimelic acid, monopropyl suberic acid, and monopropyl sebacic acid, in which propyl can be n- or isopropyl; and monobutyl oxalic acid, monobutyl malonic acid, monobutyl succinic acid, monobutyl glutaric acid, monobutyl adipic acid, monobutyl pimelic acid, monobutyl suberic acid, and monobutyl sebacic acid, in which butyl can be n-, iso-, or t-butyl. In a further preferred embodiment the aqueous cleaning composition comprises 0.01 wt.-% to 30.0 wt.-% of peracid. In other embodiments, the compositions of the present invention comprises 0.01 wt.-% to 20.0 wt.-% of a peracid. Further preferred, the composition additionally contains 0.01 to 50.0 wt.-% of hydrogen peroxide. Still further preferred, the composition comprises at least a mixture of hydrogen peroxide, peracid and the corresponding carboxylic acid. Most preferred, the composition comprises at least hydrogen peroxide, peroxyacetic acid and acetic acid. In further preferred embodiments, the compositions of the present invention comprises 0.01 wt.-% to 30.0 wt.-% of peroxyacetic acid. As the peracid, also referred to as peroxycarboxylic acid, exists as chemical equilibrium consisting of a peracid, the corresponding carboxylic acid, hydrogen peroxide and water, the quantity given as "0.01 wt.-% to 30.0 wt.-% of peracid" or given as "0.01 wt.-% to 30.0 wt.-% of peroxyacetic acid" means "0.01 wt.-% to 30 wt.-% of peracid and 0.000 wt.-% to 60.0 wt.-% of the corresponding carboxylic acid" and "0.01 wt.-% to 30.0 wt.-% of peroxyacetic acid and 0.000 wt.-% to 60.0 wt.-% of acetic acid", respectively.

Use solutions of the compositions of the present invention comprise 0.005 wt.-% to 0.2 wt.-% of peracid. Further preferred, the use solution of the composition additionally contains 0.005 wt.-% to 0.3 wt.-% of hydrogen peroxide. Still further preferred, the composition comprises at least a mixture of hydrogen peroxide, peracid and the corresponding carboxylic acid. Most preferred, the composition comprises at least hydrogen peroxide, peroxyacetic acid and acetic acid. In use solutions of the compositions of the present invention comprises 0.005 wt.-% to 0.2 wt.-% of peroxyacetic acid. As the peracid, also referred to as peroxycarboxylic acid, exists as chemical equilibrium consisting of a peracid, the corresponding carboxylic acid, hydrogen peroxide and water, the quantity given as "0.005 wt.-% to 0.2 wt.-% of peracid" or given as "0.005 wt.-% to 0.2 wt.-% of peroxyacetic acid" means "0.005 wt.-% to 0.2 wt.-% of peracid and 0.000 wt.-% to 0.4 wt.-% of the corresponding carboxylic acid" and "0.005 wt.-% to 0.2 wt.-% of peroxyacetic acid and 0.000 wt.-% to 0.4 wt.-% of acetic acid", respectively.

As one skilled in the art shall appreciate, peroxycarboxylic acids are not as stable as carboxylic acids, their stability generally increases with increasing molecular weight. Thermal decomposition of these acids can generally proceed by free radical and nonradical paths, by photodecomposition or radical-induced decomposition, or by the action of metal ions or complexes. Percarboxylic acids can be made by the direct, acid catalyzed equilibrium action of hydrogen peroxide with the carboxylic acid, by autoxidation of aldehydes, or from acid chlorides, and hydrides, or carboxylic anhydrides with hydrogen or sodium peroxide.

Making the Peroxycarboxylic Acids

Exemplary methods and apparatus for making peroxycarboxylic acids are disclosed in U.S. Patent No. 7,547,421 and U.S. Patent No. 8,017,082, both entitled "Apparatus and Method for Making a Peroxycarboxylic Acid," hereby expressly incorporated herein in its entirety by reference. These and other known methods and apparatus for making the particular peroxycarboxylic acids used according to the invention are included within the scope of the invention.

In some aspects, at ambient conditions, the reaction to make the peroxycarboxylic acid compositions may take a week or more to reach the desirable concentrations of peroxycarboxylic acid at equilibrium. In other aspects conditions can be modified to reach maximum peroxycarboxylic acid compositions within about 60 minutes or within a few hours. One skilled in the art will ascertain the various modifications to the conditions of the peroxycarboxylic acid reactions in order to obtain the desirable concentrations within a particular amount of time.

Stabilizing agents

In some embodiments, the compositions of the present invention include one or more stabilizing agents. The stabilizing agents can be used, for example, to stabilize the peracid and hydrogen peroxide and prevent the premature oxidation of this constituent within the composition of the invention. In some embodiments, an acidic stabilizing agent can be used. Thus, in some embodiments, the compositions of the present invention can be substantially free of an additional acidulant. Suitable stabilizing agents preferably are chelating agents or sequestrants. Suitable sequestrants preferably include, but are not limited to, organic chelating compounds that sequester metal ions in solution, particularly transition metal ions. Such sequestrants include organic amino- or hydroxy-polyphosphonic acid complexing agents (either in acid or soluble salt forms), carboxylic acids (e.g., polymeric polycarboxylate), hydroxycarboxylic acids, aminocarboxylic acids, or heterocyclic carboxylic acids, e.g., pyridine-2,6-dicarboxylic acid (dipicolinic acid).

It should be understood that the stabilizing agent can include mixtures of different stabilizing agents.

Since the present invention also refers to a concentrated formula, the composition is not diluted at the manufacturing site. It was discovered that the efficacy of the composition was adversely affected if the dilution water used to prepare the use solutions or ready to use solutions was less than satisfactory. By less than satisfactory, it is meant that if the dilution water had high amounts of hardness ions such as magnesium, calcium and heavy metals that chelants are able to stabilize the formulation to prevent a too fast degradation of the formulation.

The addition of a chelant allowed the composition of the invention to perform well no matter the hardness of the dilution water. Because the concentrate composition has an acidic pH, care must be taken when selecting the chelant. It was found that hydroxyethylidene-1 ,1 -diphosphonic acid (HEDP), methylglycinediacetic acid (MGDA), tetrasodium N,N-bis(carboxylatomethyl)-L-glutamate (GLDA), dipicolinic acid, ethylene diamine tetraacetic acid (EDTA), nitrilotriacetic acid (NTA), iminodisuccinic acid (IDS) and other phosphonic acids function even when the composition is acidic and allows the dilution of the concentrate with any type of water yet the diluted or ready to use solution performs as well as when the concentrate is diluted with soft water.

Exemplary chelants that can be used according to the invention include phosphonates, sodium gluconate, pentasodium salt of diethylenetriamine pentaacetic acid (available under the name Versenex®80), sodium glucoheptonate, ethylene diamine tetraacetic acid (EDTA), salts of ethylene diamine tetraacetic acid, hydroxyethyl ethylene diamine triacetic acid (HEDTA), salts of hydroxyethyl ethylene diamine triacetic acid, nitrilotriacetic acid (NTA), salts of nitrilotriacetic acid, diethanolglycine sodium salt (DEG), ethanoldiglycine disodium salt (EDG), tetrasodium N,N-bis(carboxylatomethyl)-L-glutamate (GLDA), and mixtures thereof. Exemplary salts of ethylene diamine tetraacetic acid include disodium salts, tetrasodium salts, diammonium salts, and trisodium salts. An exemplary salt of hydroxyethyl ethylene diamine triacetic acid is the trisodium salt.

Suitable chelant that can be used in the first component are iminodisuccinate, preferably the sodium salt of iminodisuccinate, hydroxyethylidene diphosphonic acid and/or tetrasodium N,N-bis(carboxylatomethyl)-L-glutamate (GLDA).

In other embodiments, the sequestrant can be or include phosphonic acid or phosphonate salt. Suitable phosphonic acids and phosphonate salts include 1 - hydroxy ethylidene-l,l-diphosphonic acid (CH₃C(P0₃H₂)₂OH) (HEDP); ethylenediamine tetrakis methylenephosphonic acid (EDTMP); diethylenetriamine pentakis methylenephosphonic acid (DTPMP); cyclohexane-l,2-tetramethylene phosphonic acid; amino[tri(methylene phosphonic acid)]; (ethylene diamine[tetra methylene-phosphonic acid)]; 2-phosphonobutane-1 ,2,4-tricarboxylic acid; or salts thereof, such as the alkali metal salts, ammonium salts, or alkyloyl amine salts, such as mono, di, or tetra-ethanolamine salts.

Commercially available chelating agents include phosphonates sold under the trade name DEQUEST® including, for example, 1 - hydroxyethylidene-1 ,1 -diphosphonic acid, available from Monsanto Industrial Chemicals Co., St. Louis, Mo., as DEQUEST® 2010; amino(tri(methylenephosphonic acid)), available from Monsanto as DEQUEST® 2000; ethylenediamine[tetra(methylenephosphonic acid)] available from Monsanto as DEQUEST® 2041 ; and 2-phosphonobutane-1 ,2,4-tricarboxylic acid available from Mobay Chemical Corporation, Inorganic Chemicals Division, Pittsburgh, Pa., as Bayhibit AM.

The sequestrant can be or include aminocarboxylic acid type sequestrant. Suitable aminocarboxylic acid type sequestrants include the acids or alkali metal salts thereof, e.g. amino acetates and salts thereof. Suitable aminocarboxylates include N- hydroxyethylaminodiacetic acid; hydroxyethylenediaminetetraacetic acid, nitrilotriacetic acid (NTA); ethylenediaminetetraacetic acid (EDTA); N-hydroxyethyl- ethylenediaminetriacetic acid (HEDTA); diethylenetriaminepentaacetic acid (DTPA); and alanine-N,N-diacetic acid; and the like; and mixtures thereof.

In a preferred embodiment, from 0.01 to 5 wt.-%, 0.25 to 4 wt.-%, 0.3 to 3 wt.-%, 0.5 to 2 wt.-% stabilizing agent, i.e. chelant and/or sequestrant, is included in the composition concentrate, and from 0.001 to 0.01 wt.-% in the use solution.

Aqueous Diluent

Water is provided in the composition of the invention in the undiluted concentrate and is also used as the diluent to prepare the ready to use solution. Water is suitable as a diluent in compositions of this invention particularly because of its unquestionable economic advantages over other liquid diluents. The aqueous diluent used in the concentrated composition of this invention is water in an amount from about 10 wt.-% up to about 65 wt.-% or from about 20 wt.-% up to about 60 wt.-%. When preparing the concentrated composition of the invention, the manufacturer has control over the water that is used. In an embodiment softened, deionized, distilled, or neutral water is used to prepare the concentrated composition of this invention.

The water used to prepare the concentrate may be very different than the water used to prepare the ready to use solution. One will readily recognize that when providing a concentrate, the water used to dilute the concentrate to a ready to use solution is beyond the control of the manufacturer. Therefore, the concentrated composition of the invention must allow for variances in the water quality. As addressed above, the chelant included in the composition is one method of allowing for variances in the water quality of the diluent used to prepare the ready to use solution. One of ordinary skill in this art will be aware of the fact that, the pH of tap water can vary with hardness and other factors. Hard water with a pH approaching 10 is known, as is water with a pH on the slightly acid side, therefore, a chelant may be included to provide for fluctuations in hardness which might be introduced by slightly alkaline tap water.

Concentrate compositions of the invention are diluted with water in about a 1 to about 200 dilution of concentrate to water to prepare the use solution.

The inventive aqueous cleaning composition and the method according to the invention will be further described in the following examples which are meant to exemplify the present invention without restricting its scope. In the following all amounts mentioned refer to wt.-% based on the whole liquid detergent concentrate composition unless otherwise indicated.

Examples

Example 1 : Aqueous cleaning compositions comprising a mixture of surfactant in combination with a peracid leading to increased amounts of peracid

In order to show the peracid generation diverse aqueous solutions comprising different surfactants and peroxyacetic acid were prepared. The content of peroxyacetic acid and hydrogen peroxide was checked after 7 days storage at 20 °C by titration.

First, 25 ml 25% of sulphuric acid were added to the solution to be tested. Then titration was carried out with 0.1 N potassium permanganate (0.1 normal = 0.02 molar) up to a change to a persistent weak pink colour. Subsequently, 1 spatula of potassium- or sodium iodide and 2 ml 1 % starch solution was added. Immediately thereafter, titatration was carried out with 0.1 N sodium thiosulphate until the solution turned from blue to colourless.

The calculation of the hydrogen peroxide and peracid content, respectively, was based as follows: Titre of 0.1 N potassium permanaganate in ml x 17 = concentration of hydrogen peroxide in ppm (mg/l)

Titre of 0.1 N sodium thiosulfate in ml x 38 = concentration peroxyacetic acid in ppm (mg/l)

The results are summarized in table 1 . The table shows the use of different surfactants in combination with peroxyacetic acid. The results demonstrate that the surfactant alkylbenzene sulfonic acid (see solutions S1 and S2) shows a synergistic effect with regards to the generation of peroxyacetic acid compared to surfactants of the same chemical class as well as different surfactant classes (see solutions S3, S4, S5) and compared to aqueous solutions without any surfactant used as control (C). The amount of surfactant was calculated based on their active substance content to achieve comparable level of surfactant between the different types of surfactant.

Table 1 :

Example 2: Foaming properties

The aqueous solution according to the present invention is for cleaning and disinfecting hard surfaces. The teats or udder e.g. of cattle are cleaned by means of rotating brushes of a milking robot equipment before milking. These brushes therefore needs to be cleaned and sanitized by spraying a disinfectant on the rotating brushes. The application of spaying products on the cleaning brushes is a very specific application in terms of the requirements for the foam profile. The application solution has to be prepared in a tank or dose-in line which requires a low or non foaming profile. Afterwards the product has to be sprayed on the brushes, wherein foaming properties are required to increase the contact time on the brush. Therefore, a foam profile is required which is a combination of low foaming CIP (cleaning-in- place) and stronger foaming COP (cleaning-out-of-place).

The diverse aqueous cleaning compositions prepared according to example 1 (see table 1 ) were tested in respect to their foaming properties. The foam profile of the different mixtures was evaluated by using the Kruss DFA 100 instrument (Kruss GmbH, Hamburg, Germany).

The DFA100 instrument is for analyzing foams and measures the foamability of liquids and the foam stability based on precise measurements of the foam height. The device makes use of an accurately controlled foaming process with electronic gas flow control. The optical sensor measures the quantity of foam produced and the decay characteristic precisely and with high resolution.

The parameters used in the foam test are shown in the following table 2: Table 2:

The results are summarized in Figure 1 . The graphs in Figure 1 display the foam profile of the different surfactant combinations. Figure 1 shows a balanced foam profile for the aqueous cleaning compositions comprising alkylbenzene sulfonic acid (S1 and S2) depending on the concentration without intensive foaming at certain applications which make this synergistic approach suitable for CIP as well as COP.

Claims

1 . An aqueous cleaning composition for cleaning and disinfecting hard surfaces, said aqueous cleaning composition comprising or consisting of:

a) alkylbenzene sulfonic acid,

b) peracid,

c) hydrogen peroxide,

d) optionally stabilizing agent, and

e) water.

2. The composition according to claim 1 , wherein the alkylbenzene sulfonic acid is C9-18 alkylbenzene sulfonic acid, preferably C-m-ie alkylbenzene sulfonic acid, more preferred C-io-13 alkylbenzene sulfonic acid; still further preferred linear alkylbenzene sulfonic acid, more preferably linear C-io-13 alkylbenzene sulfonic acid; in particular linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13.

3. The composition according to claim 1 , wherein the alkylbenzene sulfonic acid is linear alkylbenzene sulfonic acid, preferably linear do-13 alkylbenzene sulfonic acid.

4. The composition according to claim 1 , wherein the alkylbenzene sulfonic acid is linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13.

5. The composition according to any one or more of claims 1 to 4, further comprising stabilizing agents.

6. The composition according to any one or more of claims 1 to 5, wherein the peracid is selected from:

a) peracids corresponding to general formula (I) R¹-0₂C-(CH₂)p-C0₃H, wherein R¹ is hydrogen or an alkyl group containing 1 to 4 carbon atoms and p is an integer from 1 to 4, or salts thereof; b) phthalimidopercarboxylic acids (II) wherein the percarboxylic acid contains 1 to 18 carbon atoms, or salts thereof;

7. The composition according to any one or more of claims 1 to 5, wherein the peracid is selected from:

8. The composition according to any one or more of claims 1 to 5, wherein the peracid is selected from peracetic acid, perpropionic acid, peroctanoic acid, phthalimidoperhexanoic acid, phthalimidoperoctanoic acid, persuccinic acid, persuccinic acid monomethyl ester, perglutaric acid, perglutaric acid monomethyl ester, peradipic acid, peradipic acid monomethyl ester, persuccinic acid, and persuccinic acid monomethyl ester.

9. The composition according to any one or more of claims 1 to 8, comprising 0.01 to 15.0 wt.-% of alkylbenzene sulfonic acid, 0.01 to 30.0 wt.-% of peracid and 0.01 to 50.0 wt.-% of hydrogen peroxide.

10. The composition according to any one or more of claims 1 to 9, wherein the peracid is present in an equilibrium reaction mixture with hydrogen peroxide, the corresponding acid and water.

1 1 . The composition according to any one or more of claims 1 to 9, wherein the peracid is peroxyacetic acid and present in an equilibrium reaction mixture with hydrogen peroxide, acetic acid and water.

12. The composition according to any one or more of claims 1 to 1 1 comprising or consisting of:

a) 0.01 to 15.0 wt.-% of alkylbenzene sulfonic acid,

b) 0.01 to 30.0 wt.-% of peracid,

c) 0.01 to 50.0 wt.-% of hydrogen peroxide,

d) 0.000 to 2.0 wt.-% of a stabilizing agent, and

e) adding up to 100 wt.-% with water.

13. The composition according to any one or more of claims 1 to 1 1 comprising or consisting of:

a) 0.01 to 15.0 wt.-% of alkylbenzene sulfonic acid, preferably C₉-i₈ alkylbenzene sulfonic acid, further preferred C-m-ie alkylbenzene sulfonic acid, more preferred C-io-₁₃ alkylbenzene sulfonic acid; still further preferred linear alkylbenzene sulfonic acid, more preferably linear C-io-₁₃ alkylbenzene sulfonic acid; in particular linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13;

b) 0.01 to 30.0 wt.-% of peroxyacetic acid,

c) 0.01 to 50.0 wt.-% of hydrogen peroxide,

e) adding up to 100 wt.-% with water.

14. Use solution of the composition according to any one or more of claims 1 to 1 1 , comprising or consisting of:

a) 0.005 to 0.1 wt.-% of alkylbenzene sulfonic acid,

b) 0.005 to 0.2 wt.-% of peracid,

c) 0.005 to 0.3 wt.-% of hydrogen peroxide,

d) 0.000 to 0.01 wt.-% of a stabilizing agent, and

e) adding up to 100 wt.-% with water.

15. The use solution according to claim 14, comprising or consisting of:

a) 0.005 to 0.1 wt.-% of alkylbenzene sulfonic acid, preferably C₉-i₈ alkylbenzene sulfonic acid, further preferred C-io-ie alkylbenzene sulfonic acid, more preferred C-io-13 alkylbenzene sulfonic acid; still further preferred linear alkylbenzene sulfonic acid, more preferably linear C-io-13 alkylbenzene sulfonic acid; in particular linear straight chain alkylbenzene sulfonic acid in which the average number of carbon atoms in the alkyl group is from 10 to 13;

b) 0.005 to 0.2 wt.-% of peroxyacetic acid,

c) 0.005 to 0.3 wt.-% of hydrogen peroxide,

d) 0.000 to 0.01 wt.-% of a stabilizing agent, and

e) adding up to 100 wt.-% with water.

16. Use of the aqueous cleaning composition according to any one or more of claims 1 to 15 for cleaning and disinfecting hard surfaces, preferably in a CIP cleaning process or in a COP cleaning process, more preferred in a CIP cleaning process.

17. Use according to claim 16, wherein the hard surfaces are represented by the cleaning means for cleaning teats and udder of a milking robot.

18. Use according to claim 16, wherein the hard surfaces are represented by the brushes for cleaning teats and udder of a milking robot.

19. A method of cleaning and disinfecting hard surfaces, preferably in a CIP cleaning process or in a COP cleaning process, comprising contacting said hard surfaces with an aqueous cleaning composition according to any one or more of claims 1 to 15.

20. The method according to claim 19, wherein the hard surfaces are represented by the cleaning means for cleaning teats and udder of a milking robot.

21 . The method according to claim 19, wherein the hard surfaces are represented by the brushes for cleaning teats and udder of a milking robot.

21 . The method according to claim 19, comprising the following steps: a) rinsing the hard surface, preferably the brushes for cleaning teats and udder of a milking robot, with water to rinse the hard surface of soil;

b) applying the aqueous cleaning composition according to any one of claims 1 to 15 to the hard surface to clean and disinfect the hard surface;