WO2000027963A1

WO2000027963A1 - Processes of bleaching fabrics

Info

Publication number: WO2000027963A1
Application number: PCT/US1998/023982
Authority: WO
Inventors: Gloria Di Capua; Pierre Antoine Dresco; Stefano Scialla
Original assignee: The Procter & Gamble Company
Priority date: 1998-11-10
Filing date: 1998-11-10
Publication date: 2000-05-18
Also published as: WO2000027974A1; TR200101317T2; JP2003520907A; AU1699099A; CO5211000A1; EP1129166A1; AU1717400A

Abstract

According to the present invention there is provided a process for cleaning fabrics with a bleaching composition and a detergent composition.

Description

PROCESSES OF BLEACHING FABRICS

Technical Field

The present invention relates to a process of bleaching fabrics with a bleaching composition comprising a peroxycarboxylic acid.

Background of the invention

Detergent compositions suitable for laundry applications are well known in the art. It is also known that detergent compositions relying on hypochlorite as a bleaching agent can be preferred over oxygen bleaches, mainly for performance reasons, especially at lower temperatures. Typically used oxygen bleaches are the oxygen bleach precursors perborate or percarbonate that react with an activator species to produce hydrogen peroxide.

However, there are some limitations to the convenience of hypochlorite bleaches. In particular, it is well known from consumers that hypochlorite bleaching may cause yellowing and/or damage of the fabrics which are being bleached. This holds particularly true for synthetic fabrics and indeed there is a standing prejudice against using hypochlorite bleaches on synthetic fibers, as evidenced by warnings on labels of commercially available hypochlorite bleaches. Also, a variety of fabrics made of or containing synthetic fibers are labeled by their manufacturers as non-bleachable. The manufacturer is therefore faced with achieving a balance between cleaning performance and fabric and/or colour damage. The Applicant has identified a bleaching agent, peroxy carboxylic acid, that is a less aggressive bleach than hypochlorite, yet still provides improved cleaning performance versus the oxygen bleach precursor bleaching agents currently used in most fully formulated detergent compositions. Peroxy carboxylic acids are known in the art for example EP 435 379.

However, despite the apparent suitability of this bleach, it has been found that cleaning performance is occasionally not sufficient to meet consumer expectations.

It is therefore an object of the present invention to address the issues mentioned above, namely those of providing improved overall stain removal performance on a wide range of soils in addition to providing colour and fabric safety.

We have found that these issues are efficiently addressed when a fabric is cleaned using a particular process of bleaching fabrics. Indeed, it has been found that when fabrics are treated using the process of the present invention, improved bleaching performance as well as improved overall stain removal performance is delivered to the fabrics. Indeed, it has surprisingly been found that by using this process of bleaching fabrics improved greasy stain removal and especially enzymatic stain removal can be achieved as compared to the performance delivered with a conventional fully formulated detergent composition comprising the same bleaching agent. Furthermore, it has also been found that when using the process described herein fabric and/or colour damage is minimal. Hence, the Applicant believes to have achieved a balance between cleaning performance and fabric/colour damage.

Summary of the invention

The present invention relates to a process of cleaning a fabric with a bleaching composition and a detergent composition comprising the separate steps of: (a) contacting the fabric with a bleaching composition comprising a peroxycarboxylic acid, (b) contacting the fabric with a detergent composition,

(c) rinsing the fabric with water.

Detailed Description

The present invention encompasses a process of bleaching fabrics as described herein after.

By "fabrics", it is to be understood any type of fabric including for example natural and synthetic fabrics and these used to make clothes, curtains, drapes, bed linens, bath linens, table cloths, sleeping bags, tents, upholstered furniture and the like. By "natural" fabrics, it is meant fabrics made of cotton, viscose, linene, silk and/or wood. By "synthetic" fabrics, it is meant those made of synthetic fibers like polymeric fibers (polyamide, polyester, lycra® and elasthane®), and those made of both natural and synthetic fibers.

Process

The process of the present invention requires that a fabric is contacted in one step (a) with a bleaching composition and in a second separate step (b), the fabric is contacted with a detergent composition. The first step may be performed prior to the second step or alternatively the second step may be performed prior to the first step.

The steps of the process may be performed by hand, but in a preferred embodiment of the present invention, the process is carried out in a laundry washing machine having at least one rinse cycle and a wash cycle. In general, washing machines have a pre-rinse cycle wherein the fabric is moistening with at least water. This pre-rinse cycle may be followed by additional rinse cycles, but is normally followed with the main wash cycle. It is into the main wash cycle that detergent compositions are conventionally delivered. The main wash cycle is followed with at least one post-wash rinse cycle, preferably at least 2 rinse cycles. It is preferred that step (a) is performed in the pre-rinse and/or at least one of the post-wash rinse cycle. It is preferred that step (b) is performed in the main wash cycle. In the process of bleaching fabrics according to the present invention the bleaching composition remains in contact with the fabrics for a period of time sufficient to bleach the fabrics. When used in diluted form the acidic liquid aqueous composition herein remains in contact with the fabrics for up to 24 hours, preferably from 1 minute to 12 hours and more preferably from 20 minutes to 6 hours. When used in its neat form the acidic liquid aqueous composition herein remains in contact with the fabrics for up to 24 hours, preferably from 1 minute to 2 hours and more preferably from 1 minute to 1 hour.

The temperature of the bleaching process has an influence on the stain removal performance and/or bleaching performance of the bleaching compositions. More specifically, an increased temperature accelerates the bleaching process, i.e. diminishes the time required to bleach a given soil. It is therefore preferred that step (a) of the bleaching processes according to the present invention, where the bleaching composition as described herein is used in its diluted, is performed of a temperature of from 4°C to 60°C, preferably from 10°C to 50°C and most preferably from 20°C to 40°C.

The process of bleaching fabrics according to the present invention further comprises as an essential step, the step of rinsing the fabrics with water after having been contacted with the bleaching composition and the detergent composition. This can either be performed by hand in a container of water or by placing the fabric under flowing water or in a rinse cycle of a laundry washing machine.

In fact whilst one, two or all three of the steps of the present process may be carried out by hand, it is preferred for the convenience of the user that at least one, more preferably two, most preferably all steps are performed in a laundry washing machine.

Bleaching composition

The process of the present invention requires contacting a fabric with a bleaching composition comprising a pre-formed peroxy carboxylic acid (hereafter referred to as peracid). Suitable peracids are any of those known in the art. Preferred peracids are those having general formula:

O

wherein R is selected from C1-4 alkyl and n is an integer of from 1 to 5.

In a particularly preferred aspect of the present invention the peracid has the formula such that R is CH₂ and n is 5 i.e. phthaloyl amino-peroxy caproic acid or PAP.

The peracid is preferably used as a substantially water-insoluble and is available from Ausimont under the trade name Euroco.

The peracid is present may be present at a level in the composition of from 0.1% to 10% more preferably 0.5% to 8% and most preferably 1% to 6%. Alternatively the peracid may be present at a much higher level of for example 10% to 40%, more preferably from 15% to 30%, most preferably from 20% to 25%.

The bleaching composition may be in granular, but is preferably in liquid form. The term liquid is to be understood as including gel-like or pasty form as well. Where the bleaching composition is liquid, it is preferably aqueous, comprising water at a level of preferably 10 to 99%, more preferably from 50% to 98% by weight of the bleaching composition. The bleaching composition may comprise other components in addition to the peracid. Examples of such components are described herein as optional ingredients. Preferred optional components include surfactants, preferably anionic surfactants. In this embodiment it is also particularly preferred that the surfactant be present at a level of less than 5%.

Another particularly preferred component is a suspending agent. Suspending agents are components that aid or facilitate the suspension of insoluble or partially insoluble solids in a liquid environment. The peracids currently available are generally solid and substantially water insoluble. If solid particles are incorporated in a liquid composition, the particles fall to the bottom of the container holding the liquid. A way of uniformly distributing the solid (e.g. peracid) throughout the liquid composition is to incorporate suspending agent. In the present invention preferred suspending agents are polymers for example natural-gum polymers (e.g. xanthan gum), cross-linked polycarboxylic acids, polyvinyl polymers (PVA, PVP etc). Preferably the suspending agent of the present invention is selected from xanthan gum, cross-linked polycarboxylic acid and mixtures thereof.

The bleaching composition is preferably acidic i.e. the bleaching composition preferably has a pH of less than 7, more preferably from 1 to 8.5, most preferably from 3 to 4.

By "diluted form", it is meant herein that the composition as described herein after, may be diluted by the user, preferably with water. Such dilution may occur for instance in hand laundry applications as well as by the other means such as in washing machine. Said compositions can be diluted up to 500 times, preferably from 5 to 200 times and more preferably from 10 to 80 times. In a preferred embodiment herein said composition is used in its diluted form.

An advantage of the bleaching compositions suitable for use in the process of bleaching fabrics according to the present invention is that they are physically and chemically stable upon prolonged periods of storage.

Chemical stability of these compositions may be evaluated by measuring the concentration of available oxygen at given storage time after having manufactured the compositions. By "chemically stable" it is meant herein that the compositions used herein comprising a peracid do not undergo more than 15% AvO loss, in one month at 25°C and preferably not more than 10%.

Available oxygen (AvO) loss of a peracid-containing composition can be measured by titration with potassium permanganate after reduction with a solution containing ammonium ferrous sulphate. Said stability test method is well known in the art and is reported, for example, on the technical information sheet of CuroχR commercially available from Interox. Alternatively peracid concentration can also be measured using a chromatography method described in the literature for peracids (F. Di Furia et al., Gas-liquid Chromatography Method for Determination of Peracids, Analyst, Vol 113, May 1988, p 793-795).

By "physically stable" it is meant herein that no phase separation occurs in the bleaching composition used herein for a period of 7 days at 50°C.

Detergent composition

The process of the present invention requires contacting a fabric with a detergent composition. By the term detergent composition it is understood fully formulated detergent compositions currently available on the market. These compositions are those that are generally expected to be used in the wash cycle of a laundry washing machine. The detergent composition comprises conventional detergent ingredients.

Suitable conventional detergent ingredients for use in such detergent compositions are described for example in co-pending patent applications UK 96/16112.0, UK 97/13946.3, or WO 96/28531 and or EP-B-707626.

Such liquid detergent and/or granular detergent compositions may also comprise at least one or more other conventional detergent ingredients, preferably selected from builders (up to 80%), organic polymeric compounds (up to 20%), bleaching agents (up to 25%), bleach activators (up to 15%) , enzymes (typically 0.0001% to 2%), suds suppressers (up to 4%), dispersants (up to 15%), lime- soap dispersants (up to 15%), soil suspending agents (up to 20%), antiredepositions agents (up to 20%), corrosion inhibitors (up to 10%), solvents (up to 20%), chelating agents (up to 15%), dyes, pigments, perfumes and the like. The precise nature of the additional conventional detergent ingredients and levels of incorporation thereof will depend on the physical form of the detergent composition and the end characteristics of the composition desired.

The detergent composition of the present invention does not comprise a peracid, although it may comprise another mild bleach or bleach system such as a bleach precursor and a bleach activator. The detergent composition may be in granular or liquid form. Preferably, the detergent composition comprises surfactant and where present the surfactant is present at a level of greater than 5%.

The detergent composition when in liquid form or a 1% solution thereof when in granular form preferably has a pH of greater than 7, more preferably greater than 9, most preferably in the range of from 9 to 11.5. The pH of both the bleaching and detergent compositions may be adjusted using any acidic or alkaline agent known to those skilled in the art. Examples of acidic agents are organic acids such as citric acid and inorganic acids such as sulphuric acid, sulphonic acid and/or methane sulphonic acid. Examples of alkaline agents are sodium hydroxide, potassium hydroxide and/or sodium carbonate.

Typically, such liquid detergent compositions and/or granular detergent compositions may be diluted up to 250 times their weight of water to provide an alkaline solution as described herein, preferably from 2 to 200 and more preferably from 10 to 160. Such dilution may occur for instance in hand laundry application as well as by other means such as in washing machine.

Optional ingredients

The bleaching compositions used in the process of bleaching fabrics according to the present invention may comprise a variety of optional ingredients such as surfactants, chelating agents, radical scavengers, antioxidants, stabilisers, builders, soil suspenders, polymeric soil release agents, dye transfer agents, solvents, suds controlling agents, brighteners, perfumes, pigments, dyes and the like.

Surfactants

The bleaching compositions suitable for use in the process of bleaching fabrics herein preferably comprise a surfactant selected from the group consisting of nonionic surfactants, anionic surfactants, cationic surfactants, zwitterionic surfactants, amphoteric surfactants and mixtures thereof.

Where present the surfactant is present at a level of less than 5%, more preferably from 0.1 % to 4% and most preferably from 1 % to 3%. Suitable anionic surfactants for use in the compositions herein include water- soluble salts or acids of the formula ROSO3M wherein R preferably is a C-10-C24 hydrocarbyl, preferably an alkyl or hydroxyalkyl having a C10-C20 alkyl component, more preferably a C12-C18 alkyl or hydroxyalkyl, and M is H or a cation, e.g., an alkali metal cation (e.g., sodium, potassium, lithium), or ammonium or substituted ammonium (e.g., methyl-, dimethyl-, and trimethyl ammonium cations and quaternary ammonium cations, such as tetramethyl- ammonium and dimethyl piperdinium cations and quaternary ammonium cations derived from alkylamines such as ethylamine, diethylamine, triethylamine, and mixtures thereof, and the like). Typically, alkyl chains of C12-I6 are preferred for lower wash temperatures (e.g., below about 50°C) and Ci6-18 ^a'W chains are preferred for higher wash temperatures (e.g., above about 50°C).

Other suitable anionic surfactants for use herein are water-soluble salts or acids of the formula RO(A)_mSθ3M wherein R is an unsubstituted C10-C24 alkyl or hydroxyalkyl group having a C10-C24 alkyl component, preferably a C12- 20 alkyl or hydroxyalkyl, more preferably C-12-C18 alkyl or hydroxyalkyl, A is an ethoxy or propoxy unit, m is greater than zero, typically between about 0.5 and about 6, more preferably between about 0.5 and about 3, and M is H or a cation which can be, for example, a metal cation (e.g., sodium, potassium, lithium, calcium, magnesium, etc.), ammonium or substituted-ammonium cation. Alkyl ethoxylated sulfates as well as alkyl propoxylated sulfates are contemplated herein. Specific examples of substituted ammonium cations include methyl-, dimethyl-, trimethyl-ammonium and quaternary ammonium cations, such as tetramethyl-ammonium, dimethyl piperdinium and cations derived from alkanolamines such as ethylamine, diethylamine, triethylamine, mixtures thereof, and the like. Exemplary surfactants are C12-C18 alkyl polyethoxylate (1.0) sulfate, Ci2-C-|8^E(¹ -0)M), C12-C18 alkyl polyethoxylate (2.25) sulfate, C12- C^<|8E(2.25)M), C12-C18 alkyl polyethoxylate (3.0) sulfate C^<|2-Ci8E(3.0), and

C12-C18 alkyl polyethoxylate (4.0) sulfate Ci2-C-|8^E(^{4 0})^M). wherein M is conveniently selected from sodium and potassium.

Other particularly suitable anionic surfactants for use herein are alkyl sulphonates including water-soluble salts or acids of the formula RSO3M wherein R is a CQ-

C22 linear or branched, saturated or unsaturated alkyl group, preferably a C-12- C-|8 alkyl group and more preferably a C14-C16 alkyl group, and M is H or a cation, e.g., an alkali metal cation (e.g., sodium, potassium, lithium), or ammonium or substituted ammonium (e.g., methyl-, dimethyl-, and trimethyl ammonium cations and quaternary ammonium cations, such as tetramethyl- ammonium and dimethyl piperdinium cations and quaternary ammonium cations derived from alkylamines such as ethylamine, diethylamine, triethylamine, and mixtures thereof, and the like).

Suitable alkyl aryl sulphonates for use herein include water- soluble salts or acids of the formula RSO3M wherein R is an aryl, preferably a benzyl, substituted by a

Cβ-C22 linear or branched saturated or unsaturated alkyl group, preferably a C-12-C18 alkyl group and more preferably a C14-C16 alkyl group, and M is H or a cation, e.g., an alkali metal cation (e.g., sodium, potassium, lithium, calcium, magnesium etc) or ammonium or substituted ammonium (e.g., methyl-, dimethyl-, and trimethyl ammonium cations and quaternary ammonium cations, such as tetramethyl-ammonium and dimethyl piperdinium cations and quaternary ammonium cations derived from alkylamines such as ethylamine, diethylamine, triethylamine, and mixtures thereof, and the like).

The alkylsulfonates and alkyl aryl sulphonates for use herein include primary and secondary alkylsulfonates and primary and secondary alkyl aryl sulphonates. By "secondary C6-C22 alkyl or C6-C22 alkyl aryl sulphonates", it is meant herein that in the formula as defined above, the S03M or aryl-S03M group is linked to a carbon atom of the alkyl chain being placed between two other carbons of the said alkyl chain (secondary carbon atom).

For example C14-C16 alkyl sulphonate salt is commercially available under the name Hostapur ® SAS from Hoechst and C8-alkylsulphonate sodium salt is commercially available under the name Witconate NAS 8® from Witco SA. An example of commercially available alkyl aryl sulphonate is Lauryl aryl sulphonate from Su.Ma. Particularly preferred alkyl aryl sulphonates are alkyl benzene sulphonates commercially available under trade name Nansa® available from Albright&Wilson.

Other anionic surfactants useful for detersive purposes can also be used herein. These can include salts (including, for example, sodium, potassium, ammonium, and substituted ammonium salts such as mono-, di- and triethanolamine salts) of soap, C8-C24 olefinsulfonates, sulfonated polycarboxylic acids prepared by sulfonation of the pyrolyzed product of alkaline earth metal citrates, e.g., as described in British patent specification No. 1 ,082,179, C8-C-24 alkylpolyglycolethersulfates (containing up to 10 moles of ethylene oxide); alkyl ester sulfonates such as C 14.-16 methyl ester sulfonates; acyl glycerol sulfonates, fatty oleyl glycerol sulfates, alkyl phenol ethylene oxide ether sulfates, paraffin sulfonates, alkyl phosphates, isethionates such as the acyl isethionates, N-acyl taurates, alkyl succinamates and sulfosuccinates, monoesters of sulfosuccinate (especially saturated and unsaturated C-12-C18 rnonoesters) diesters of sulfosuccinate (especially saturated and unsaturated C6-C14 diesters), sulfates of alkylpolysaccharides such as the sulfates of alkylpolyglucoside (the nonionic nonsulfated compounds being described below), branched primary alkyl sulfates, alkyl polyethoxy carboxylates such as those of the formula RO(CH₂CH₂0)_kCH₂COO-M⁺ wherein R is a Cg-C₂₂ alkyl, k is an integer from 0 to 10, and M is a soluble salt-forming cation. Resin acids and hydrogenated resin acids are also suitable, such as rosin, hydrogenated rosin, and resin acids and hydrogenated resin acids present in or derived from tall oil. Further examples are given in "Surface Active Agents and Detergents" (Vol. I and II by Schwartz, Perry and Berch). A variety of such surfactants are also generally disclosed in U.S. Patent 3,929,678, issued December 30, 1975, to Laughlin, et al. at Column 23, line 58 through Column 29, line 23 (herein incorporated by reference).

Other particularly suitable anionic surfactants for use herein are alkyl carboxylates and alkyl alkoxycarboxylates having from 4 to 24 carbon atoms in the alkyl chain, preferably from 8 to 18 and more preferably from 8 to 16, wherein the alkoxy is propoxy and/or ethoxy and preferably is ethoxy at an alkoxylation degree of from 0.5 to 20, preferably from 5 to 15. Preferred alkylalkoxycarboxylate for use herein is sodium laureth 11 carboxylate (i.e., RO(C₂H₄O)₁₀-CH₂COONa, with R= C12-C14) commercially available under the name Akyposoft® lOONV from Kao Chemical Gbmh.

Suitable amphoteric surfactants for use herein include amine oxides having the following formula R<| R2R3NO wherein each of R1 , R2 and R3 is independently a saturated substituted or unsubstituted, linear or branched hydrocarbon chains of from 1 to 30 carbon atoms. Preferred amine oxide surfactants to be used according to the present invention are amine oxides having the following formula R-1 R2R3NO wherein R1 is an hydrocarbon chain comprising from 1 to 30 carbon atoms, preferably from 6 to 20, more preferably from 8 to 16, most preferably from 8 to 12, and wherein R2 and R3 are independently substituted or unsubstituted, linear or branched hydrocarbon chains comprising from 1 to 4 carbon atoms, preferably from 1 to 3 carbon atoms, and more preferably are methyl groups. R1 may be a saturated substituted or unsubstituted linear or branched hydrocarbon chain. Suitable amine oxides for use herein are for instance natural blend C8-C10 amine oxides as well as C12-C16 amine oxides commercially available from Hoechst.

Suitable zwitterionic surfactants for use herein contain both a cationic hydrophilic group, i.e., a quaternary ammonium group, and anionic hydrophilic group on the same molecule at a relatively wide range of pH's. The typical anionic hydrophilic groups are carboxylates and sulfonates, although other groups like sulfates, phosphonates, and the like can be used. A generic formula for the zwitterionic surfactants to be used herein is :

R₁-N⁺(R2)(R3)R4X-

wherein R<| is a hydrophobic group; R2 is hydrogen, CI -CR alkyl, hydroxy alkyl or other substituted C-I-CR alkyl group; R3 is CI -CR alkyl, hydroxy alkyl or other substituted C -CQ alkyl group which can also be joined to R2 to form ring structures with the N, or a CI -CR carboxylic acid group or a C-j-Cβ sulfonate group; R4 is a moiety joining the cationic nitrogen atom to the hydrophilic group and is typically an alkylene, hydroxy alkylene, or polyalkoxy group containing from 1 to 10 carbon atoms; and X is the hydrophilic group which is a carboxylate or sulfonate group.

Preferred hydrophobic groups R-| are aliphatic or aromatic, saturated or unsaturated, substituted or unsubstituted hydrocarbon chains that can contain linking groups such as amido groups, ester groups. More preferred R-| is an alkyl group containing from 1 to 24 carbon atoms, preferably from 8 to 18, and more preferably from 10 to 16. These simple alkyl groups are preferred for cost and stability reasons. However, the hydrophobic group R1 can also be an amido radical of the formula R_a-C(0)-NH-(C(Rk)2)m, wherein R_a is an aliphatic or aromatic, saturated or unsaturated, substituted or unsubstituted hydrocarbon chain, preferably an alkyl group containing from 8 up to 20 carbon atoms, preferably up to 18, more preferably up to 16, Rt, is selected from the group consisting of hydrogen and hydroxy groups, and m is from 1 to 4, preferably from 2 to 3, more preferably 3, with no more than one hydroxy group in any (C(R|-,)2) moiety.

Preferred R2 is hydrogen, or a C1-C3 alkyl and more preferably methyl. Preferred R3 is a C1-C4 carboxylic acid group or C1-C4 sulfonate group, or a

C1-C3 alkyl and more preferably methyl. Preferred R4 is (CH2)_n wherein n is an integer from 1 to 10, preferably from 1 to 6, more preferably is from 1 to 3.

Some common examples of betaine/sulphobetaine are described in U.S. Pat. Nos. 2,082,275, 2,702,279 and 2,255,082, incorporated herein by reference.

Examples of particularly suitable alkyldimethyl betaines include coconut-dimethyl betaine, lauryl dimethyl betaine, decyl dimethyl betaine, 2-(N-decyl-N, N- dimethyl-ammonia)acetate, 2-(N-coco N, N-dimethylammonio) acetate, myristyl dimethyl betaine, palmityl dimethyl betaine, cetyl dimethyl betaine, stearyl dimethyl betaine. For example Coconut dimethyl betaine is commercially available from Seppic under the trade name of Amonyl 265®. Lauryl betaine is commercially available from Albright & Wilson under the trade name Empigen BB/L®.

Examples of amidobetaines include cocoamidoethylbetaine, cocoamidopropyl betaine or C10-C14 fatty acylamidopropylene(hydropropylene)sulfobetaine. For example C10-C14 fatty acylamidopropylene(hydropropylene)sulfobetaine is commercially available from Sherex Company under the trade name "Varion CAS® sulfobetaine".

A further example of betaine is Lauryl-immino-dipropionate commercially available from Rhone-Poulenc under the trade name Mirataine H2C-HA ®.

Suitable cationic surfactants for use herein include derivatives of quaternary ammonium, phosphonium, imidazolium and sulfonium compounds. Preferred cationic surfactants for use herein are quaternary ammonium compounds wherein one or two of the hydrocarbon groups linked to nitrogen are a saturated, linear or branched alkyl group of 6 to 30 carbon atoms, preferably of 10 to 25 carbon atoms, and more preferably of 12 to 20 carbon atoms, and wherein the other hydrocarbon groups (i.e. three when one hydrocarbon group is a long chain hydrocarbon group as mentioned hereinbefore or two when two hydrocarbon groups are long chain hydrocarbon groups as mentioned hereinbefore) linked to the nitrogen are independently substituted or unsubstituted, linear or branched, alkyl chain of from 1 to 4 carbon atoms, preferably of from 1 to 3 carbon atoms, and more preferably are methyl groups. Preferred quaternary ammonium compounds suitable for use herein are non-chloride/non halogen quaternary ammonium compounds. The counterion used in said quaternary ammonium compounds are compatible with any peracid and are selected from the group of methyl sulfate, or methylsulfonate, and the like.

Particularly preferred for use in the compositions of the present invention are trimethyl quaternary ammonium compounds like myristyl trimethylsulfate, cetyl trimethylsulfate and/or tallow trimethylsulfate. Such trimethyl quaternary ammonium compounds are commercially available from Hoechst, or from Albright & Wilson under the trade name EMPIGEN CM®.

Amongst the nonionic surfactants, alkoxylated nonionic surfactants and especially ethoxylated nonionic surfactants are suitable for use herein. Particularly preferred nonionic surfactants for use herein are the capped alkoxylated nonionic surfactants as they can also provide a suds suppression benefit.

Suitable capped alkoxylated nonionic surfactants for use herein are according to the formula: R₁(0-CH₂-CH₂)_n-(OR₂)_m-0-R₃

wherein R-| is a C8-C24 linear or branched alkyl or alkenyl group, aryl group, alkaryl group, preferably R-| is a C8-C-|8 alkyl or alkenyl group, more preferably a C1O-C15 a'kyl or alkenyl group, even more preferably a C-10- 15 alkyl group; wherein R2 is a C-|-Cιo linear or branched alkyl group, preferably a C2-C10 linear or branched alkyl group ;

wherein R3 is a C-|-C-|o alkyl or alkenyl group, preferably a C1-C5 alkyl group, more preferably methyl;

and wherein n and m are integers independently ranging in the range of from 1 to 20, preferably from 1 to 10, more preferably from 1 to 5; or mixtures thereof.

These surfactants are commercially available from BASF under the trade name Plurafac®, from HOECHST under the trade name Genapol® or from ICI under the trade name Symperonic®. Preferred capped nonionic alkoxylated surfactants of the above formula are those commercially available under the tradename Genapol® L 2.5 NR from Hoechst, and Plurafac® from BASF.

Chelating agents

The bleaching compositions suitable for use in the process of bleaching fabrics herein may comprise a chelating agent as a preferred optional ingredient. Suitable chelating agents may be any of those known to those skilled in the art such as the ones selected from the group comprising phosphonate chelating agents, amino carboxylate chelating agents, other carboxylate chelating agents, polyfunctionally-substituted aromatic chelating agents, ethylenediamine N,N'- disuccinic acids, or mixtures thereof.

The presence of chelating agents contribute to further enhance the chemical stability of the compositions. A chelating agent may be also desired in the compositions herein as it allows to increase the ionic strength of the compositions and thus their stain removal and bleaching performance on various surfaces.

Suitable phosphonate chelating agents for use herein may include alkali metal ethane 1-hydroxy diphosphonates (HEDP), alkylene poly (alkylene phosphonate), as well as amino phosphonate compounds, including amino aminotri(methylene phosphonic acid) (ATMP), nitrilo trimethylene phosphonates (NTP), ethylene diamine tetra methylene phosphonates, and diethylene triamine penta methylene phosphonates (DTPMP). The phosphonate compounds may be present either in their acid form or as salts of different cations on some or all of their acid functionalities. Preferred phosphonate chelating agents for use herein are diethylene triamine penta methylene phosphonate (DTPMP) and ethane 1- hydroxy diphosphonate (HEDP). Such phosphonate chelating agents are commercially available from Monsanto under the trade name DEQUEST®-

Polyfunctionally-substituted aromatic chelating agents may also be useful in the compositions herein. See U.S. patent 3,812,044, issued May 21 , 1974, to Connor et al. Preferred compounds of this type in acid form are dihydroxydisulfobenzenes such as 1 ,2-dihydroxy -3,5-disulfobenzene.

A preferred biodegradable chelating agent for use herein is ethylene diamine N,N'- disuccinic acid, or alkali metal, or alkaline earth, ammonium or substitutes ammonium salts thereof or mixtures thereof. Ethylenediamine N,N'- disuccinic acids, especially the (S,S) isomer have been extensively described in US patent 4, 704, 233, November 3, 1987, to Hartman and Perkins. Ethylenediamine N,N'- disuccinic acids is, for instance, commercially available under the tradename ssEDDS® from Palmer Research Laboratories.

Suitable amino carboxylates to be used herein include ethylene diamine tetra acetates, diethylene triamine pentaacetates, diethylene triamine pentaacetate (DTPA).N- hydroxyethylethylenediamine triacetates, nitrilotri-acetates, ethylenediamine tetrapropionates, triethylenetetraaminehexa-acetates, ethanol- diglycines, propylene diamine tetracetic acid (PDTA) and methyl glycine di-acetic acid (MGDA), both in their acid form, or in their alkali metal, ammonium, and substituted ammonium salt forms. Particularly suitable amino carboxylates to be used herein are diethylene triamine penta acetic acid, propylene diamine tetracetic acid (PDTA) which is, for instance, commercially available from BASF under the trade name Trilon FS® and methyl glycine di-acetic acid (MGDA).

Further carboxylate chelating agents to be used herein include salicylic acid, aspartic acid, glutamic acid, glycine, malonic acid or mixtures thereof.

Another chelating agent for use herein is of the formula:

wherein R^«| , R2, R3, and R4 are independently selected from the group consisting of -H, alkyl, alkoxy, aryl, aryloxy, -Cl, -Br, -NO2, -C(0)R\ and -SO2R"; wherein R' is selected from the group consisting of -H, -OH, alkyl, alkoxy, aryl, and aryloxy; R" is selected from the group consisting of alkyl, alkoxy, aryl, and aryloxy; and R5, RQ, R7, and Rs are independently selected from the group consisting of -H and alkyl.

Particularly preferred chelating agents to be used herein are amino aminotri(methylene phosphonic acid), di-ethylene-triamino-pentaacetic acid, diethylene triamine penta methylene phosphonate, 1 -hydroxy ethane diphosphonate, ethylenediamine N, N'-disuccinic acid, and mixtures thereof.

Typically, the compositions suitable for use in the process of bleaching fabrics herein comprise up to 5% by weight of the total composition of a chelating agent, or mixtures thereof, preferably from 0.01% to 1.5% by weight and more preferably from 0.01 % to 0.5%.

Radical scavengers

The bleaching compositions suitable for use in the process of bleaching fabrics herein may comprise a radical scavenger or a mixture thereof.

Suitable radical scavengers for use herein include the well-known substituted mono and dihydroxy benzenes and their analogs, alkyl and aryl carboxylates and mixtures thereof. Preferred such radical scavengers for use herein include di-tert- butyl hydroxy toluene (BHT), hydroquinone, di-tert-butyl hydroquinone, mono-tert- butyl hydroquinone, tert-butyl-hydroxy anysole, benzoic acid, toluic acid, catechol, t-butyl catechol, benzylamine, 1,1 ,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl) butane, n-propyl-gallate or mixtures thereof and highly preferred is di-tert-butyl hydroxy toluene. Such radical scavengers like N-propyl-gallate may be commercially available from Nipa Laboratories under the trade name Nipanox S1 ®. Radical scavengers when used, are typically present herein in amounts ranging from up to 10% by weight of the total composition and preferably from 0.001 % to 0.5% by weight.

The presence of radical scavengers may contribute to the chemical stability of the bleaching compositions herein as well as to the safety profile of these compositions.

Test methods:

The bleaching performance may be evaluated by the following test methods on various type of bleachable stains.

A suitable test method for evaluating the bleaching performance on a soiled fabric according to the process of bleaching of the present invention is the following: First a typical step (b) is carried out either in a washing-machine (e.g., by introducing 225 g of a conventional detergent, e.g. Ariel future® in the detergent dispenser of a typical washing machine, e.g., Sangiorgio Exacta 352ZX ® and running a washing cycle with the soiled fabrics) or in a hand soaking operation (e.g., by contacting soiled fabrics with a soaking solution typically obtained by diluting a conventional detergent, e.g., Ariel a mano®, at a dilution level of 140ml/1 Outers of water -typical soaking time is 1 minute to several hours). Then a bleaching composition as described herein is diluted with water typically at a dilution level of 1 to 100 ml/L, preferably 20 ml/L (composition :water), then the fabrics having previously undergone step (b) as described herein above, are soaked in the bleaching composition for 20 minutes to 6 hours (i.e. step (a)) and then rinsed (i.e. step (c)). Alternatively the bleaching composition can be used in the washing machine at a dilution level of typically at a dilution level of 1 to 100 ml/L (composition :water). In the washing machine the soiled fabrics are bleached at a temperature of from 30° to 90°C for 10 to 100 minutes and then rinsed. Soiled fabrics/swatches with for example tea, coffee and the like may be commercially available from E.M.C. Co. Inc..

The bleaching performance is then evaluated by comparing side by side the soiled fabrics treated accordingly to where the cleaning process only involves cleaning with a detergent composition in step (b) and step (a) is not used. A visual grading may be used to assign difference in panel units (psu) in a range from 0 to 4.

The stain removal performance may be evaluated with the same test method but with soiled fabrics soiled by different types of stains like enzymatic ones and/or greasy ones.

Examples

The following compositions were made by mixing the listed ingredients in the listed proportions (weight % unless otherwise specified). These compositions are suitable to be used in the "bleaching step" of the bleaching processes of the present invention.

Compositions I II III IV V

(% weight) Na alkylbenzene sulphonate - 1 - 1.5 -

Linear alkyl sulfonate - - 1 0.5 -

C12-15alkyI 7 ethoxylated - 1 - - -

Akyposoft 100 NV® - - 2 -

PAP 3 2 4 1 20 Hydroxyethanediphosphonate 0.1 0.05 0.16 0.1 0.1

Perfume - 0.2 0.2 0.3 - brightener - 0.01 0.05 0.03 - xanthan gum 0.3 0.2 0.3 - 0.5 carbopol ETD 2691 0.2 - 0.1 - carbopol ETD 2623 - - - 0.3 - carboxylmethoxycellulose - 1 0.5 1 -

Alkanizing / acidizing agent up to pH 3 3..99 2.5 3.5 4 4

Akyposoft 100 NV® is a C12-C14 alkyl ethoxy 10 carboxylate commercially available from Kao Chemicala Gmbh. Witkonate NAS 8® is an alkylsulphonate available from Witco AS

HEDP is ethane 1 -hydroxy diphosphonate commercially available from Monsanto under the serie Dequest®.

PAP is phthalimidoperoxyhexanoic acid available from Ausimont under the tradename Euroco®

Carbopol®ETD 2623 and 2991 are polymers available from BFGoodrich The following compositions are representative of the granular detergent compositions suitable to be diluted with water to provide an alkaline solution suitable to be used in the first step (alkaline step) of the process herein.

A B C D

LAS 8.0 8.0 5.25 4.8

TAS - - 1.25 1.6

C25E3 3.4 3.4 - 1.2

C45E7 - - 3.25 5.0

QAS - 0.8 0.8 2.0

Zeolite A 18.1 18.1 - 19.5

STPP - - 19.7 -

NaSKS-6/citric acid - - - 10.6

(79:21)

Carbonate 13.0 13.0 6.1 21.4

Bicarbonate - - - 2.0

Silicate 1.4 1.4 6.8 -

Sulfate 26.1 26.1 39.8 14.3

PB4 9.0 9.0 5.0 2.5

TAED 1.5 1.5. 0.5 0.25

DETPMP 0.25 0.25 0.25 0.2

HEDP 0.3 0.3 - 0.3

Enzymes 0.003 0.004 0.01 0.015

MA/AA 0.3 0.3 0.8 1.6

CMC 0.2 0.2 0.2 0.4

Photoactivated 15 15 15 27 bleach (ppm)

Brightener 0.09 0.09 0.08 0.19

Perfume 0.3 0.3 0.3 0.3

Silicone antifoam 0.5 0.5 0.5 2.4

Misc/minors to 100%

Density in g/litre 850 850 750 750 Blown Powder

Zeolite A 15.0 15.0 -

Sodium sulfate 0.0 5.0 -

LAS 3.0 3.0 -

DETPMP 0.4 0.5 -

CMC 0.4 0.4 -

MA/AA 4.0 4.0 -

Agglomerates

C45AS - - 11.0

LAS 6.0 5.0 -

TAS 3.0 2.0 -

Silicate 4.0 4.0 -

Zeolite A 10.0 15.0 13.0

CMC - - 0.5

MA/AA - - 2.0

Carbonate 9.0 7.0 7.0

Spray On

Perfume 0.3 0.3 0.5

C45E7 4.0 4.0 4.0

C25E3 2.0 2.0 2.0

Dry additives

MA/AA - - 3.0

NaSKS-6 - - 12.0

Citrate 10.0 - 8.0

Bicarbonate 7.0 3.0 5.0

Carbonate 8.0 5.0 7.0

PVPVI/PVNO 0.5 0.5 0.5

Pectin degrading enzyme 0.05 0.005 0.02

Protease 0.026 0.016 0.047

Lipase 0.009 0.009 0.009

Amylase 0.005 0.005 0.005

Cellulase 0.006 0.006 0.006

Silicone antifoam 5.0 5.0 5.0 Dry additives

Sodium sulfate 0.0 9.0 0.0

Balance (Moisture and 100.0 100.0 100.0

Miscellaneous)

Density (g/litre) 700 700 700

The following compositions are representative of the liquid detergent compositions suitable to be used diluted with water to provide an alkaline solution suitable to be used in the first step of the process of bleaching fabrics according to the present invention.

H I J K L M N O

LAS 10.0 13.0 9.0 - 25.0 - - -

C25AS 4.0 1.0 2.0 10.0 - 13.0 18.0 15.0

C25E3S 1.0 - - 3.0 - 2.0 2.0 4.0

C25E7 6.0 8.0 13.0 2.5 - - 4.0 4.0

TFAA - - - 4.5 - 6.0 8.0 8.0

QAS - - - - 3.0 1.0 - -

TPKFA 2.0 - 13.0 2.0 - 15.0 7.0 7.0

Rapeseed fatty - - - 5.0 - - 4.0 4.0 acids

Citric 2.0 3.0 1.0 1.5 1.0 1.0 1.0 1.0

Dodecenyl/ 12.0 10.0 - - 15.0 - - - tetradecenyl succinic acid

Oleic acid 4.0 2.0 1.0 - 1.0 - - -

Ethanol 4.0 4.0 7.0 2.0 7.0 2.0 3.0 2.0

1 ,2 Propanediol 4.0 4.0 2.0 7.0 6.0 8.0 10.0 13.-

Mono Ethanol - - - 5.0 - - 9.0 9.0

Amine

Tri Ethanol - - 8 - - - - -

Amine

NaOH (pH) 8.0 8.0 7.6 7.7 8.0 7.5 8.0 8.2

Ethoxylated 0.5 - 0.5 0.2 - - 0.4 0.3 tetraethylene pentamine

DETPMP 1.0 1.0 0.5 1.0 2.0 1.2 1.0 -

SRP 2 0.3 - 0.3 0.1 - - 0.2 0.1

PVNO - - - - - - - 0.10

Enzymes .007 .009 .009 .009 .01 .013 .011 .015

Boric acid 0.1 0.2 - 2.0 1.0 1.5 2.5 2.5

Na formate _ - 1.0 - - - - - Ca chloride - 0.01 - 0.01 -

Bentonite clay - - - - 4.0 4.0 -

Suspending clay - - - - 0.6 0.3 -

SD3

Balance Moisture 100 100 100 100 100 100 100 100 and

Miscellaneous

LAS Sodium linear C-J2 alkyl benzene sulphonate

TAS Sodium tallow alkyl sulphate

QAS R2.N⁺(CH3)2(C₂H₄OH) with R2 = C12-C14 TFAA C16-C18 alkyl N-methyl glucamide.

TPKFA C12-C14 topped whole cut fatty acids. NaSKS-6 Crystalline layered silicate of formula 5-Na2Si2θ5

Carbonate Anhydrous sodium carbonate with a particle size between 200 μm and 900μm.

Bicarbonate Anhydrous sodium bicarbonate with a particle size between 400 μm and 1200μm.

STPP Anhydrous sodium tripolyphosphate

MA/AA Copolymer of 1 :4 maieic/acrylic acid, average molecular weight about 80,000

Zeolite A Hydrated Sodium Aluminosilicate of formula Na-|2(A1θ2Siθ2)i2- 27H2O having a primary particle size in the range from 0.1 to 10 micrometers

Citrate Tri-sodium citrate dihydrate of activity 86,4% with a particle size distribution between 425 μm and 850 μm.

PB1 Anhydrous sodium perborate monohydrate bleach, empirical formula NaBo2.H202 PB4 Anhydrous sodium perborate tetrahydrate

TAED Tetraacetyl ethylene diamine. Photoactivated Sulfonated zinc phtlocyanine encapsulated in dextrin Bleach soluble polymer.

CMC Sodium carboxymethyl cellulose.

HEDP 1 ,1-hydroxyethane diphosphonic acid.

DETPMP Diethylene triamine penta (methylene phosphonic acid), marketed by Monsanto under the Trade name Dequest 2060.

PVNO Poly(4-vinylpyridine)-N-Oxide. PVPVI Poly (4-vinylpyridine)-N-oxide/copolymer of vinyl- imidazole and vinyl-pyrrolidone.

Silicone antifoam Polydimethylsiloxane foam controller with siloxane- oxyalkylene copolymer as dispersing agent with a ratio of said foam controller to said dispersing agent of 10:1 to 100:1.

SRP 2 Diethoxylated poly (1 ,2 propylene terephtalate) short block polymer.

PPT 10-propionic phenothiazine BUS Butyl syringate Sulphate Anhydrous sodium sulphate.

Examples of processes of bleaching fabrics according to the present invention

The following processes of bleaching fabrics will illustrate the present invention:

Any of the combination "alkaline stepVbleaching step" below are suitable, provided that the "alkaline step" is before the "bleaching step".

In soaking vessel

"Alkaline step" Alkaline detergent Water volume rinse

(ml) (liters)

50 5L no

100 5L yes

100 10L no

200 10L no

In soakinq vessel

"Bleachinq step" Peracid Water volume rinse composition

(ml) (liters)

50 5L yes

100 5L yes

150 10L yes

200 10L ves

In washing machine "Alkaline step" Addition step Alkaline detergent

(ml) in the main wash 150 in the main wash 150 in the main wash 300

In washing machine "Bleaching step" Addition step Peracid composition (ml) during rinse cycle 50 during rinse cycle 100 during main wash ^* 50 during main wash ^* 100

"during main wash*" of the bleaching step it is to be understood that a washing cycle is run with the bleaching composition in absence of detergent composition, the bleaching composition being introduced directly in the detergent dispenser without the presence of the detergent or in the bleach dispenser if the machine is so provided.

The alkaline detergent used in the processes of bleaching fabrics as exemplified herein above can be any of the conventional detergent compositions available on the market, e.g. Ariel future, Dash future® when used in a washing machine, or Ariel a Mano® when used in a hand washing application. The peracid containing compositions used in these processes can be any of the ones exemplified herein before, compositions I to V.

Any washing machine may be used herein include European types as well as US types or Japanese types. An example is for instance San Giorgio Exacta 252 ZX.

All the above processes provide excellent bleaching performance as well as effective stain removal performance when bleaching fabrics as above indicated while being safe to the fabrics and colors.

Claims

1. A process for cleaning a fabric with a bleaching composition and a detergent composition comprising the separate steps of:

(a) contacting the fabric with a bleaching composition comprising a preformed peroxy carboxylic acid,

(b) contacting the fabric with a detergent composition,

(c) rinsing the fabric with water.

2. A process according to claim 1 wherein step (a) is performed prior to step (b).

3. A process according to claim 1 wherein step (b) is performed prior to step (a).

4. A process according to any preceding claim wherein the pre-formed peroxy carboxylic acid has general formula:

o

O

wherein R is C1-4 alkyl and n is an integer of from 1 to 5.

5. A process according to claim 4 wherein the pre-formed peroxy carboxylic acid has the formula wherein R is CH₂ and n is 5.

6. A process according to any preceding claim wherein the bleaching composition has pH of from 1 to 6.5.

7. A process according to any preceding claim wherein the bleaching composition comprises surfactant at a level of less than 5% by weight of the composition.

8. A process according to any preceding claim wherein the pre-formed peroxy carboxylic acid is solid and substantially water-insoluble.

9. A process according to any preceding claim wherein the bleaching composition additionally comprises at least one suspending agent, preferably comprising at least one polymer.

10. A process according to any preceding claim wherein the detergent composition has alkaline pH of greater than 7.

11. A process according to any preceding claim wherein the detergent composition comprises more than 5% surfactant.

12. A process according to any preceding claim performed in a laundry washing machine having at least one rinse cycle and a wash cycle.

13. A process according to claim 12 wherein step (a) is performed in at least one rinse cycle of the washing machine.

14. A process according to claim 12 or 13 wherein step (b) is performed in the wash-cycle of the washing machine.