EP1029912A1

EP1029912A1 - Bleaching compositions comprising an oligocarboxylate and a complex-facilitating co-agent

Info

Publication number: EP1029912A1
Application number: EP99870030A
Authority: EP
Inventors: Andrea Briatore; Giovanni Grande; Michael Alan John Moss; Oreste Todini
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1999-02-16
Filing date: 1999-02-16
Publication date: 2000-08-23

Abstract

Bleaching compositions are disclosed which comprise a hypohalite bleach, an oligocarboxylate and a complex-facilitating co-agent. Said bleaching compositions provide fabric yellowing-prevention and/or fabric safety benefits. A process of treating fabrics with such a bleaching composition is also disclosed.

Description

Technical field

The present invention relates to bleaching compositions, in particular to hypochlorite bleaching compositions, suitable for use in laundry applications such as hand washing as well as washing with automatic laundry washing machines.

Background of the invention

Bleach-containing compositions for bleaching various surfaces, e.g., fabrics, are well known in the art.
Amongst the different bleaching compositions available, those relying on bleaching by hypohalite bleach, such as hypochlorite, are often preferred, mainly for bleaching performance reasons.
However, a drawback associated with the use of hypohalite bleach-containing compositions, e.g., hypochlorite-based compositions, is that said compositions may damage and/or cause yellowing of the fabrics being bleached. During the bleaching operation, a liquid hypochlorite-containing composition for example, can be applied onto the fabric in neat or diluted form. The hypochlorite bleach can be present in various forms, including hypochlorous acid and in the form of various derivatives resulting from its decomposition pathways. Hypochlorous acid and these derivatives can react with fabrics and may cause damage and/or yellowing of fabrics being bleached.
Therefore, bleaching compositions are often formulated comprising bleach and a fabric protection system. Compositions comprising bleach and one of various fabric protection systems are well known in the art. An example is a bleaching composition based on hypohalite bleach comprising an oligocarboxylate (European Patent Application No. 97870118.3).
However, there are some limitations to the use, especially regarding the fabric protection, of said bleaching composition comprising a fabric protection system. In particular, it is known from consumer research that said bleaching composition may still damage and/or yellow the fabrics which are being bleached.
It is therefore an objective of the present invention to provide a bleach-containing composition, suitable for use in laundry applications, whereby fabric yellowing-prevention benefits are provided.
It is a further objective of the present invention to provide a bleaching composition, suitable for use in laundry application, whereby fabric safety benefits are provided.
It has been found that the above objectives can be met by formulating a hypohalite bleach-containing bleaching composition comprising a particular oligocarboxylate as described herein after and a complex-facilitating co-agent. The compositions of the present invention provide fabric yellowing-prevention and/or fabric safety benefits on fabrics bleached therewith. Particularly, the fabric yellowing-prevention and/or fabric safety are improved, as compared to the fabric yellowing-prevention and/or fabric safety delivered by the use of the same compositions comprising an oligocarboxylate but without a complex-facilitating co-agent.
A further advantage of the bleaching compositions of the present invention is that they are suitable for the bleaching of different types of fabrics including natural fabrics, (e.g., fabrics made of cotton and linen), synthetic fabrics such as those made of polymeric fibres of synthetic origin (e.g., polyamide-elasthane), as well as those made of both natural and synthetic fibres. For example, the bleaching compositions of the present invention based on hypohalite bleaches, such as hypochlorite may be used on synthetic fabrics despite a standing prejudice against using such bleaches on synthetic fabrics, as evidenced by warnings on labels of commercially available hypochlorite-containing compositions and clothes.
A further advantage of the bleaching compositions of the present invention is that said bleaching compositions are suitable for various laundry bleaching applications both when used in diluted conditions, e.g., as a detergent additive or a fully formulated laundry detergent composition, and when used in neat condition, e.g., as a liquid pretreater (spotter).

Background art

Hypohalite bleach-containing compositions, like hypochlorite-containing compositions suitable for bleaching fabrics have been described in the art.
The European Patent Application No. 97870118.3 discloses compositions comprising a hypohalite bleach and an oligocarboxylate as described herein. However, the combination of such an oligocarboxylate with a co-agent as described herein is not disclosed.
EP-A-622 451 discloses compositions comprising hypochlorite, sodium hydroxide, a bleach stable perfume and a buffering system whereby the pH of the diluted composition is buffered to a constant value throughout use. However, the combination of such an oligocarboxylate and a co-agent as described herein, let alone together with a catalyst is not disclosed.
EP-A-653 482, EP-A-668 345 and EP-A-688 857 disclose hypochlorite-containing compositions comprising a source of strong alkalinity, a pH buffering means and optionally other types of ingredients such as respectively radical scavengers, polycarboxylate acids of pyridine and periodates. However, the combination of such an oligocarboxylate and a co-agent as described herein, let alone together with a catalyst is not disclosed.

Summary of the invention

The present invention encompasses a liquid or solid bleaching composition comprising a hypohalite bleach, a complex-facilitating co-agent and from 0.001% to 3% by weight of the total composition of an oligocarboxylate according to the formula:
wherein : n is an integer of from 0 to 20; the substituents R₁ and R₄ are independently selected from the group consisting of : -(CH₂)_pCOOH;-(CH₂)_p(CHCOOH)_qCH₃; -(CHCOOH)_qCH₃-(CH₂)_p(CHCOOH)_qCOOH; and-(CHCOOH)_qCOOH; the substituents R₂ and R₃ are independently selected from the group consisting of : hydrogen; -CH₃; -COOH; -(CH₂)_pCH₃;-(CH₂)_pCOOH; -(CH₂)_p(CHCOOH)_qCH₃; -(CHCOOH)_qCH₃;-(CH₂)_p(CHCOOH)_qCOOH; and -(CHCOOH)_qCOOH; wherein p is an integer of from 1 to 20; and wherein q is an integer of from 1 to 20.
In a preferred embodiment of the present invention said complex-facilitating co-agent has at least one functional group selected from the group consisting of : an alkoxy group; an amine oxide group; a positively charged nitrogen ion; a betaine or a sulfobetaine moiety; and a hydroxy group.
In a preferred embodiment of the present invention the compositions herein further comprise a catalyst, to further enhance the fabric safety and/or yellowing-prevention performance delivered by the compositions of the present invention when used to bleach a fabric.
In another preferred embodiment the compositions of the present invention further comprise a pH buffering component. The presence of a pH buffering component in the compositions of the present invention further contributes to the effective yellowing-prevention performance and/or fabric safety of these compositions.
The present invention also encompasses a process of bleaching fabrics wherein said fabrics are contacted with a bleaching composition according to the present invention.
The present invention further encompasses the use of a complex-facilitating co-agent in a bleaching composition comprising a hypohalite bleach and an oligocarboxylate, whereby fabric yellowing-prevention and/or fabric safety benefits are provided.

Detailed Description of the invention

The bleaching compositions may be formulated either as solids or liquids.
In the case where the bleaching compositions are formulated as solids, for example as granules, tablets or powders, they are preferably applied on the fabrics to be bleached according to the present invention in a liquid form, i.e., solid compositions are used in combination with an appropriate solvent, typically water.
In the case where the bleaching compositions are formulated as liquids including gel and paste form, the bleaching compositions are preferably but not necessarily formulated as aqueous compositions. Liquid bleaching compositions are preferred herein for convenience of use. Preferred liquid bleaching compositions of the present invention are aqueous and therefore, preferably may comprise water, more preferably may comprise water in an amount of from 60% to 98%, even more preferably of from 80% to 97% and most preferably 85% to 97% by weight of the total composition.

Hypohalite bleach

As a first essential ingredient, the bleaching compositions of the present invention comprise a hypohalite bleach or a mixture thereof.
Suitable hypohalite bleaches may be provided by a variety of sources, including bleaches that lead to the formation of positive halide ions and/or hypohalite ions, as well as bleaches that are organic based sources of halides, such as chloroisocyanurates.
Suitable hypohalite bleaches for use herein include the alkali metal and alkaline earth metal hypochlorites, hypobromites, hypoiodites, chlorinated trisodium phosphate dodecahydrates, potassium and sodium dichloroisocyanurates, potassium and sodium trichlorocyanurates, N-chloroimides, N-chloroamides, N-chloroamines and chlorohydantoins.
In a preferred embodiment wherein the bleaching compositions are liquid, said hypohalite bleach is an alkali metal and/or alkaline earth metal hypochlorite. More preferably, for liquid bleaching compositions said hypohalite bleach is an alkali metal and/or alkaline earth metal hypochlorite selected from the group consisting of sodium hypochlorite, potassium hypochlorite, magnesium hypochlorite, lithium hypochlorite and calcium hypochlorite, and mixtures thereof. Even more preferably, for liquid bleaching compositions said hypohalite bleach is sodium hypochlorite.
In another preferred embodiment wherein the bleaching compositions are solid, said hypohalite bleach is : an alkali metal or alkaline earth metal hypochlorite; chlorinated trisodium phosphate dodecahydrate; potassium dichloroisocyanurate; sodium dichloroisocyanurate; potassium trichlorocyanurate; sodium trichlorocyanurate; or a mixture thereof. More preferably, for solid bleaching compositions said hypohalite bleach is : an alkali metal or alkaline earth metal hypochlorite selected from the group consisting of lithium hypochlorite and calcium hypochlorite; chlorinated trisodium phosphate dodecahydrate; potassium dichloroisocyanurate; sodium dichloroisocyanurate; potassium trichlorocyanurate; sodium trichlorocyanurate; or a mixture thereof. Even more preferably, for solid bleaching compositions said hypohalite bleach is sodium dichloroisocyanurate and/or calcium hypochlorite.
Preferably, the liquid bleaching compositions according to the present invention comprise said hypohalite bleach such that the content of active halide in the composition is of from 0.01% to 20% by weight, more preferably from 0.1% to 10% by weight, even more preferably from 0.5% to 6% and most preferably from 1 % to 6% by weight of the composition.
Preferably, the solid bleaching compositions according to the present invention comprise said hypohalite bleach such that the content of active halide in the composition is of from 20% to 95% by weight, more preferably from 25% to 60% by weight of the composition.

Oligocarboxylate

As a second essential ingredient, the bleaching compositions according to the present invention comprise an oligocarboxylate as described herein or a mixture thereof.
Suitable oligocarboxylates for use herein are according to the formula:
wherein : n is an integer of from 0 to 20; the substituents R₁ and R₄ are independently selected from the group consisting of : -(CH₂)_pCOOH;-(CH₂)_p(CHCOOH)_qCH₃; -(CHCOOH)_qCH₃-(CH₂)_p(CHCOOH)_qCOOH; and-(CHCOOH)_qCOOH; the substituents R₂ and R₃ are independently selected from the group consisting of : hydrogen; -CH₃; -COOH; -(CH₂)_pCH₃;-(CH₂)_pCOOH; -(CH₂)_p(CHCOOH)_qCH₃; -(CHCOOH)_qCH₃;-(CH₂)_p(CHCOOH)_qCOOH; and -(CHCOOH)_qCOOH; wherein p is an integer of from 1 to 20; and wherein q is an integer of from 1 to 20.
Preferably n is an integer of from 0 to 10, more preferably of from 0 to 3 and most preferably n is 0, 1 or 2. Preferably p and q independently are integers of from 1 to 10, more preferably from 1 to 5, more preferably p and/or q are 1 or 2 and most preferably are 1.
More preferably the substituents R₁ and R₄ independently are -(CH₂)_pCOOH, wherein p is an integer of from 1 to 10, preferably from 1 to 5 and more preferably p is 1 or 2.
Preferably the substituents R₂ and R₃ independently are hydrogen, -CH₃,-(CH₂)_pCOOH, or -COOH; wherein p is an integer of from 1 to 10, preferably from 1 to 5 and more preferably is 1 and more preferably R₂ and R₃ each independently are hydrogen, -(CH₂)_pCOOH, or -COOH.
Examples of preferred oligocarboxylates for use herein include 1,2,3,4-butane tetracarboxylate and/or 1,2,3-propanetricarboxylate. Sodium 1,2,3,4-butane tetracarboxylate has been found to be particularly suitable to use according to the present invention.
Sodium 1,2,3,4-butane tetracarboxylate may be commercially available from Aldrich (reagent grade materials) and/or from K&K Laboratories.
Preferably, the bleaching compositions according to the present invention comprise from 0.001% to 3%, more preferably from 0.01% to 3%, even more preferably from 0.2% to 2% and most preferably from 0.5% to 1.5% by weight of the total composition of said oligocarboxylate or a mixture thereof.

Complex-facilitating co-agent

As a third essential ingredient, the bleaching compositions according to the present invention comprise a complex-facilitating co-agent. Preferably, said complex-facilitating co-agent facilitates the binding of said oligocarboxylate with the fibres of a fabric treated with said bleaching composition.
Any complex-facilitating co-agent having the desired property of facilitating the binding of said oligocarboxylate with the fibres of a fabric treated with said bleaching composition may be used.
Suitable complex-facilitating co-agents have at least one functional group selected from the group consisting of: an alkoxy group; an amine oxide group; a positively charged nitrogen ion; a betaine or a sulfobetaine moiety; and a hydroxy group.
Suitable complex-facilitating co-agents having an alkoxy group are alkoxylated surfactants. Suitable alkoxylated surfactants herein include non-capped or capped alkoxylated nonionic surfactants, alkyl alkoxylated sulphates, alkyl alkoxylated carboxylates and alkyl alkoxylated methylcarboxylates and mixtures thereof.
Suitable non-capped alkoxylated nonionic surfactants are according to the formula RO-(A)_nH, wherein : R is a C₆ to C₂₂, preferably a C₈ to C₂₂ alkyl chain, or a C₆ to C₂₈ alkyl benzene chain; A is an ethoxy or propoxy or butoxy unit; and wherein n is from 0 to 20, preferably from 1 to 15 and, more preferably from 2 to 15 and most preferably from 2 to 12. Preferred R chains for use herein are the C₈ to C₂₂ alkyl chains. Non-capped ethoxy/butoxylated, ethoxy/propoxylated, butoxy/propoxylated and ethoxy/butoxy/propoxylated nonionic surfactants may also be used herein. Preferred non-capped alkoxylated nonionic surfactants are non-capped ethoxylated nonionic surfactants.
Suitable non-capped ethoxylated nonionic surfactants for use herein are Dobanol® 91-2.5 (HLB= 8.1; R is a mixture of C₉ and C₁₁ alkyl chains, n is 2.5), or Lutensol® TO3 (HLB=8; R is a C₁₃ alkyl chains, n is 3), or Lutensol® AO3 (HLB=8; R is a mixture of C₁₃ and C₁₅ alkyl chains, n is 3), or Tergitol® 25L3 (HLB= 7.7; R is in the range of C₁₂ to C₁₅ alkyl chain length, n is 3), or Dobanol® 23-3 (HLB=8.1; R is a mixture of C₁₂ and C₁₃ alkyl chains, n is 3), or Dobanol® 23-2 (HLB=6.2; R is a mixture of C₁₂ and C₁₃ alkyl chains, n is 2), or Dobanol® 45-7 (HLB=11.6; R is a mixture of C₁₄ and C₁₅ alkyl chains, n is 7) Dobanol® 23-6.5 (HLB=11.9; R is a mixture of C₁₂ and C₁₃ alkyl chains, n is 6.5), or Dobanol® 25-7 (HLB=12; R is a mixture of C₁₂ and C₁₅ alkyl chains, n is 7), or Dobanol® 91-5 (HLB=11.6; R is a mixture of C₉ and C₁₁ alkyl chains, n is 5), or Dobanol® 91-6 (HLB=12.5 ; R is a mixture of C₉ and C₁₁ alkyl chains, n is 6), or Dobanol® 91-8 (HLB=13.7 ; R is a mixture of C₉ and C₁₁ alkyl chains, n is 8), Dobanol® 91-10 (HLB=14.2 ; R is a mixture of C₉ to C₁₁ alkyl chains, n is 10), Dobanol® 91-12 (HLB=14.5 ; R is a mixture of C₉ to C₁₁ alkyl chains, n is 12), or mixtures thereof. Preferred herein are Lutensol® TO3, or Lutensol® AO3, or Tergitol® 25L3, or Dobanol® 23-3, or Dobanol® 23-6.5, or Dobanol® 45-7, Dobanol® 91-8, or Dobanol® 91-10, or Dobanol® 91-12, or mixtures thereof. These Dobanol® surfactants are commercially available from SHELL. These Lutensol® surfactants are commercially available from BASF and these Tergitol® surfactants are commercially available from UNION CARBIDE.
Suitable capped alkoxylated non-ionic surfactants, having the terminal hydroxyl group capped, are according to the formula : R(A)n-O-R1 where R and R1 are independently a C₁ to C₃₀, preferably a C₁ to C₂₀ alkyl chain, or a C₁ to C₁₈ alkyl benzene chain; A is an ethoxy or propoxy or butoxy unit; n is from 0 to 20, preferably from 1 to 15 and, more preferably from 2 to 15 and most preferably from 2 to 12. Capped ethoxy/butoxylated, ethoxy/propoxylated, butoxy/propoxylated and ethoxy/butoxy/propoxylated nonionic surfactants may also be used herein. A suitable capped alkoxylated non-ionic surfactants for use herein is for instance Plurafac® LF231 commercially available from BASF.
Suitable chemical processes for preparing the alkoxylated nonionic surfactants for use herein include condensation of corresponding alcohols with alkylene oxide, in the desired proportions. Such processes are well known to the person skilled in the art and have been extensively described in the art.
Suitable alkyl alkoxylated sulphate surfactants for use herein are according to the formula RO(A)_mSO₃M wherein : R is an unsubstituted C₆-C₂₀ alkyl or hydroxyalkyl group having a C₆-C₂₀ alkyl component, preferably a C₁₂-C₂₀ alkyl or hydroxyalkyl, more preferably C₁₂-C₁₈ alkyl or hydroxyalkyl; A is an ethoxy or propoxy or butoxy unit; m is greater than zero, typically between 0.5 and 6, more preferably between 0.5 and 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 and alkyl butoxylated 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 (C₁₂-C₁₈E(1.0)SM), C₁₂-C₁₈ alkyl polyethoxylate (2.25) sulfate (C₁₂-C₁₈E(2.25)SM), C₁₂-C₁₈ alkyl polyethoxylate (3.0) sulfate (C₁₂-C₁₈E(3.0)SM), and C₁₂-C₁₈ alkyl polyethoxylate (4.0) sulfate (C₁₂-C₁₈E(4.0)SM), wherein M is conveniently selected from sodium and potassium.
Suitable alkyl alkoxylated carboxylate surfactants for use herein are according to the formula RO(A)_mCO₂M wherein : R is an unsubstituted C₆-C₂₀ alkyl or hydroxyalkyl group having a C₆-C₂₀ alkyl component, preferably a C₁₂-C₂₀ alkyl or hydroxyalkyl, more preferably C₁₂-C₁₈ alkyl or hydroxyalkyl; A is an ethoxy or propoxy or butoxy unit; m is greater than zero, typically between 0.5 and 6, more preferably between 0.5 and 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 carboxylates as well as alkyl propoxylated carboxylates and alkyl butoxylated carboxylates 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) carboxylate (C₁₂-C₁₈E(1.0)CM), C₁₂-C₁₈ alkyl polyethoxylate (2.25) carboxylate (C₁₂-C₁₈E(2.25)CM), C₁₂-C₁₈ alkyl polyethoxylate (3.0) carboxylate (C₁₂-C₁₈E(3.0)CM), and C₁₂-C₁₈ alkyl polyethoxylate (4.0) carboxylate (C₁₂-C₁₈E(4.0)CM), wherein M is conveniently selected from sodium and potassium.
Suitable alkyl alkoxylated methylcarboxylates surfactants for use herein are according to the formula RO(A)_mCH₂CO₂M wherein : R is an unsubstituted C₆-C₂₀ alkyl or hydroxyalkyl group having a C₆-C₂₀ alkyl component, preferably a C₁₂-C₂₀ alkyl or hydroxyalkyl, more preferably C₁₂-C₁₈ alkyl or hydroxyalkyl; A is an ethoxy or propoxy or butoxy unit; m is greater than zero, typically between 0.5 and 6, more preferably between 0.5 and 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 methylcarboxylates as well as alkyl propoxylated methylcarboxylates and alkyl butoxylated methylcarboxylates 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) methylcarboxylates (C₁₂-C₁₈E(1.0)CH₂CO₂M), C₁₂-C₁₈ alkyl polyethoxylate (2.25) methylcarboxylates (C₁₂-C₁₈E(2.25)CH₂CO₂M), C₁₂-C₁₈ alkyl polyethoxylate (3.0) methylcarboxylates (C₁₂-C₁₈E(3.0)CH₂CO₂M), and C₁₂-C₁₈ alkyl polyethoxylate (4.0) methylcarboxylates (C₁₂-C₁₈E(4.0)CH₂CO₂M), wherein M is conveniently selected from sodium and potassium.
Suitable complex-facilitating co-agents having a betaine or sulfobetaine moiety include betaine or sulfobetaine surfactants.
Suitable betaine or sulfobetaine surfactants are according to the formulae :
wherein : R₁ and R₂ are each independently linear or branched, saturated or unsaturated hydrocarbon chains of from 1 to 30, preferably 1 to 20, more preferably 1 to 7, carbon atoms; R₃ is a linear or branched hydrocarbon chain of from 8 to 30, preferably of from 10 to 20, more preferably 12 to 18 carbon atoms; n is an integer of from 1 to 20, preferably 1 to 10, more preferably 1 to 5; and M is H or an alkali metal, or mixtures thereof.
Examples of suitable betaine or sulfobetaine surfactants include coconut-dimethyl betaine commercially available from Albright & Wilson.
Suitable complex-facilitating co-agents having an amine oxide group include the amine oxide surfactants corresponding to the formula : R₁R₂R₃NO wherein each of R₁, R₂ and R₃ is independently a saturated or unsaturated, 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 : R₁R₂R₃NO 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 saturated or unsaturated, 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 or unsaturated, 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, preferred amine oxide is C₁₂-C₁₄ dimethyl amine oxide commercially available from Albright & Wilson.
Suitable complex-facilitating co-agents having a positively charged nitrogen ion include quaternary ammonium surfactants according to the formula : R₁R₂R₃R₄N⁺ X^-, wherein X is a counteranion such as halogen, methyl sulphate, methyl sulphonate, or hydroxide; R₁ is a saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl group containing from 1 to 30 carbon atoms, preferably from 12 to 20, more preferably from 8 to 20; and R₂, R₃ and R₄ are each independently hydrogen or saturated or unsaturated, substituted or unsubstituted, linear or branched alkyl groups containing from 1 to 4 carbon atoms, preferably from 1 to 3 and more preferably methyl. In highly preferred quaternary ammonium surfactants herein R₁ is a C₁₀-C₁₈ hydrocarbon chain, most preferably C₁₂, C_14,, or C₁₆; and R₂, R₃ and R₄ are all three methyl, and X is halogen, preferably bromide or chloride, most preferably bromide.
Examples of quaternary ammonium surfactants are myristyl trimethylammonium methyl sulphate, cetyl trimethylammonium methyl sulphate, lauryl trimethyl ammonium bromide, stearyl trimethyl ammonium bromide (STAB), cetyl trimethyl ammonium bromide (CTAB) and myristyl trimethyl ammonium bromide (MTAB). Highly preferred herein are lauryl trimethyl ammonium salts. Such trimethyl quaternary ammonium surfactants may be commercially available from Hoechst, or from Albright & Wilson under the trade name Empigen CM®.
Suitable complex-facilitating co-agents having a hydroxy group include tertiary alcohols, polyalcohols, and mixtures thereof.
Suitable tertiary alcohols and polyalcohols are according to the following formula :
wherein : R₁, R₂ and R₃ are independently linear or branched, saturated or unsaturated hydrocarbon chains of from 1 to 30, preferably 1 to 20, more preferably 1 to 7, carbon atoms optionally comprising one or more C₅ to C₇, preferably C₆, aromatic or aliphatic ring structures; and m, m', m" n, n', n", o, o' and o" are independently integers of from 0 to 1000, preferably 0 to 100, more preferably 0 to 50.
Examples of suitable tertiary alcohols include tert-butyl alcohol, tert-amyl alcohol.
An example of a suitable polyalcohol is 2,4 dimethyl butane-2,4-diol.
Suitable tertiary alcohols and polyalcohols are commercially available from Aldrich.
Preferred complex-facilitating co-agents are selected from the group consisting of : alkoxylated surfactants; amine oxide surfactants; quaternary ammonium surfactants; betaine and sulfobetaine surfactants; tertiary alcohols and polyalcohols; and mixtures thereof. More preferred complex-facilitating co-agents herein are capped alkoxylated nonionic surfactants, alkyl alkoxylated sulphates or tertiary alcohols or mixtures thereof. Most preferred complex-facilitating co-agents herein are Sodium C_12-14 polyethoxylate (3.0) sulfate, C₁₂-C₁₄ dimethyl amine oxide, tert-butyl alcohol or tert-amyl alcohol or mixtures thereof.
Preferably, the liquid bleaching compositions according to the present invention comprise from 0.01% to 20%, more preferably from 0.05% to 10%, even more preferably from 0.05% to 5% and most preferably from 0.05% to 2% by weight of the total composition of said complex-facilitating co-agent or a mixture thereof.
Preferably, the solid bleaching compositions according to the present invention comprise from 0.01% to 40%, more preferably from 0.2% to 20%, even more preferably from 0.5% to 10% and most preferably from 0.5% to 5% by weight of the total composition of said complex-facilitating co-agent or a mixture thereof.
Cotton fabrics contain cellulose (i.e., (C₆H₁₀O₅)_n). When a bleach-containing composition, e.g., a hypochlorite-containing composition, is used to bleach a cotton fabric, the bleach may react with the hydroxyl substituents of cellulose in position 6, 2, 3 and 5 of the cellulosic ring and thus may introduce new functional groups like carbonylic, aldehydic and/or carboxylic groups. Synthetic fabrics may be made of various synthetic materials like polyamide-elasthane that also comprises hydroxyl groups capable of being oxidised by bleach. The applicant believes that it is these new functional groups that cause fabric damage and/or yellowing.
It has now been found that oligocarboxylates and complex-facilitating co-agents in a hypohalite bleach-containing composition in combination act as fabric protection agent when this composition is used to bleach fabrics. Oligocarboxylates as described herein are capable of binding the hydroxyl groups of a fabric thereby protecting said hydroxyl group from reacting with the bleach. Indeed, it has been found that the binding of the oligocarboxylates to the hydroxyl groups can be facilitated by the presence of a complex-facilitating co-agent. This results in an excellent yellowing-prevention performance and/or the fabric safety profile of a hypohalite bleach-containing composition comprising them. These results can be seen both when the liquid bleaching compositions of the present invention is used in neat condition, e.g. as a pretreater, as well as in diluted conditions, e.g. typical dilution with water in conventional washing conditions, as well as when the solid bleaching compositions of the present invention is used.
Indeed, the present invention is based on the finding that by facilitating the binding of the hydroxyl groups of a fabric due to the presence of a complex-facilitating co-agent, the oxidation of said hydroxyl groups that otherwise occurs when bleaching a fabric with a hypohalite bleach-containing composition like a hypochlorite-containing composition, is reduced. According to the present invention, such interaction can take place on various types of fabrics including not only cotton fabrics but also synthetic fabrics like polyamide-elasthane fabrics, despite the low accessibility and reactivity of the hydroxyl groups of such fabrics, thereby further improving fabric yellowing-prevention and/or fabric safety.
By "binding", it is meant herein any interaction between the carboxylic groups of the oligocarboxylates present in the compositions of the present invention and the hydroxyl groups of a fabric bleached in presence of such compositions, including esterification, Van der Waals interactions, covalent bindings and so on.
By "facilitated binding", it is meant herein that the interaction as described above between the oligocarboxylate and the fabric is enhanced due to the presence of said complex-facilitating co-agent.
The degree of binding between fabric fibres and the oligocarboxylates as described herein may be evaluated by different test methods including the cellulose viscosity test method. In this test method cellulose powder (commercially available from Aldrich) is mixed with a composition (in a liquid form, preferably with water as the solvent) comprising an oligocarboxylate as described herein and a co-agent as described herein. Said mixture is stirred for 30 minutes. After separation by filtration, the cellulose fraction is solubilized in a Cu(ll)ethylenediamine solution (1:1 with water) according to DIN 54270 for measuring the viscosity of cellulose (commercially available from Merck). The viscosity of the resulting solution is measured by a capillary viscometer (e.g., an AVS 500 automatic viscometer available from Italscientifica S.r.l.-ltaly) versus a reference cellulose sample treated with an equal molar concentration of NaCI to subtract the eventual ionic strength effect and prepared as described above without adding a composition comprising an oligocarboxylate as described herein and a complex-facilitating co-agent.
The facilitated binding between fabric fibres and the oligocarboxylates due to the complex-facilitating co-agent, can be evaluated by comparing the cellulose viscosity of cellulose treated with a composition comprising an oligocarboxylate as described herein and a co-agent as described herein to the cellulose viscosity of cellulose treated with the same composition without the complex-facilitating co-agent being present or the same composition without the oligocarboxylate being present.
Indeed, the fabric yellowing-prevention benefit and/or safety effect benefit of the present invention can be evaluated by comparing the bleaching composition according to the present invention to the same bleach-containing composition without the co-agent as described herein being present or the same bleach-containing composition without the oligocarboxylate being present.
By "fabric yellowing-prevention benefit", it is meant herein that the yellowing of fabrics, i.e., the appearance of a yellowish tone of said fabrics, that may occur by using the hypohalite bleach-containing compositions of the present invention (e.g., those containing a hypochlorite bleach) is reduced, compared to the yellowing that occurs by using the same compositions without the complex-facilitating co-agent as described herein.
The degree of yellowing can be determined by both visual and instrumental grading. Visually, the difference in yellowing between items treated with different compositions can be determined by a team of expert panellists. Instrumentally, the assessment can be determined with the help of Colorimeters such as Ganz Griesser® instruments (e.g., Datacolor® Spectraflash® SF 500, Machbet White-eye® 500) or a ZEISS ELREPHO® or others which are available for instance from Hunterlab® or Gardner®.
By "fabric safety benefit", it is meant herein that the damage that may be caused to fabrics by using the hypohalite bleach-containing compositions of the present invention (e.g., those containing a hypochlorite bleach) is reduced, compared to the damage caused by using the same compositions without the complex-facilitating co-agent as described herein.
Fabric safety may be evaluated by different test methods including the degree of polymerisation test method according to UNI (Ente Nazionale Italiano di Unificazione) official method UNI 8282-Determinazione della viscosity intrinseca in soluzione di cuprietilendiammina (CED).
Another aspect of the present invention is the use of a complex-facilitating co-agent in a bleaching composition comprising a hypohalite bleach and an oligocarboxylate, whereby fabric yellowing-prevention and/or fabric safety benefits are provided, preferably said complex-facilitating co-agent, has at least one functional group selected from the group consisting of an alkoxy group, an amine oxide group, a positively charged nitrogen ion, a betaine or a sulfobetaine moiety and a hydroxy group.

pH

The pH of the liquid bleaching compositions according to the present invention, as is, is typically from 8 to 14 measured at 25°C, preferably from 10 to 13.5 and more preferably from 11 to 13.5. Solid bleaching compositions or liquid bleaching compositions of the invention have a pH of from 7.5 to 13, preferably from 8 to 12, more preferably from 8.5 to 11.5, when diluted into 1 to 500 times its weight of water. It is in this alkaline range that the optimum stability and performance of the hypohalite as well as fabric yellowing-prevention and/or safety are obtained. The pH range can suitably be provided by the pH buffering component mentioned hereinafter and the hypohalite bleach mentioned hereinbefore, which are alkalis. However, in addition to these components, an alkalinity source may also optionally be used.
Suitable alkalinity sources for use herein are the caustic alkalis, such as sodium hydroxide, potassium hydroxide and/or lithium hydroxide, and/or the alkali metal oxides such, as sodium and/or potassium oxide or mixtures thereof. A preferred alkalinity source is a caustic alkali, more preferably sodium hydroxide and/or potassium hydroxide.
Other suitable alkalinity sources include ammonia, ammonium carbonate and hydrogen carbonate.
Typical levels of such alkalinity sources, when present, are of from 0.1% to 5% by weight, preferably from 0.3% to 2% and more preferably from 0.5% to 1.5% by weight of the composition.

Catalysts

In a preferred embodiment, the bleaching compositions according to the present invention further comprise a catalyst or a mixture thereof.
Suitable catalysts for use herein are according to the formula X_aM wherein X is Cl, Br, O or OH, wherein M is zinc, tin, titanium, bismuth, aluminium, germanium, cobalt, magnesium or antimony, and wherein a is an integer of from 1 to 6 (depending on the oxidation state of M).
Particularly suitable catalysts for use herein are titanium alcoxides such as tetrabutoxytitanium, titaniumchloride, ZnCl₂, Al(OH)₃, SnCl₂, BiCl₂, TiO₂, Co₃O₄, CoSO₄ and/or GeO₂. Particularly preferred herein is ZnCl₂ and/or SnCl₂.
Zinc chloride is commercially available from Mineral Research and Development Corporation US.
Tin chloride is commercially available from Aldrich and Fluka (reagent grade materials).
Other suitable catalysts for use herein also include bismuth subcarbonate and/or subnitrate.
Preferably, the liquid bleaching compositions according to the present invention may comprise up to 2%, more preferably from 0.01% to 1% by weight, even more preferably from 0.04% to 0.5% and most preferably from 0.05% to 0.3% by weight of the total composition of said catalyst or a mixture thereof
Preferably, the solid bleaching compositions according to the present invention may comprise up to 5%, more preferably from 0.01% to 2% by weight, even more preferably from 0.05% to 1% and most preferably from 0.1% to 0.6% by weight of the total composition of said catalyst or a mixture thereof.
Such catalysts are present in preferred compositions according to the present invention as they contribute to even further improve the yellowing-prevention performance and/or fabric safety of the compositions of the present invention. Indeed, it is believed that in the bleaching process, the presence of a catalyst even further facilitates and thus enhances the binding of the hydroxyl groups of the fabric by the oligocarboxylate salt, thereby promoting fibre crosslinking.
Accordingly, the addition of such a catalyst to a bleaching composition comprising a hypohalite bleach, an oligocarboxylate and a complex-facilitating co-agent allows to significantly further increase the yellowing-prevention performance and/or the fabric safety profile of said composition.

pH buffering components

A pH buffering component is an optional but highly preferred component of the bleaching compositions of the present invention. The pH buffering component ensures that the pH of the composition is buffered to a pH value ranging from 7.5 to 13, preferably from 8 to 12, more preferably from 8.5 to 11.5 after the composition has been diluted into 1 to 500 times its weight of water.
Suitable pH buffering components for use herein are selected from the group consisting of alkali metal salts of carbonates, polycarbonates, sesquicarbonates, silicates, polysilicates, boron salts, boric acid, phosphates, stannates, alluminates and mixtures thereof. The preferred alkali metal salts for use herein are sodium and potassium.
Suitable boron salts or mixtures thereof for use herein include alkali metal salts of borates and alkyl borates and mixtures thereof. Examples of boron salts include alkali metal salts of metaborate, tetraborate, octoborate, pentaborate, dodecaboron, borontrifluoride and alkyl borate containing from 1 to 12 carbon atoms, preferably from 1 to 4. Suitable alkyl borate includes methyl borate, ethyl borate and propyl borate. Particularly preferred boron salts herein are the alkali metal salts of metaborate, such as sodium metaborate, potassium metaborate, and the alkali metal salts of borate, such as sodium borate, or mixtures thereof. Boron salts like sodium metaborate and sodium tetraborate are commercially available from Borax and Societa Chimica Larderello under the name sodium metaborate and Borax®.
Particularly preferred pH buffering components are selected from the group consisting of sodium carbonate, sodium silicate, sodium borate, sodium metaborate and mixtures thereof.
The raw materials involved in the preparation of hypohalite bleaches usually contain by-products, e.g., calcium carbonate resulting in an amount of up to 0.4% by weight of by-product within the hypohalite composition. However, at such amount, the by-product will not have the buffering action defined above.
Liquid bleaching compositions herein will preferably contain an amount of pH buffering component of from 0.5% to 9% by weight, preferably from 0.5% to 5% by weight, and more preferably in an amount of from 0.6% to 3% by weight of the composition.
Solid bleaching compositions herein will preferably contain an amount of pH buffering component of from 3% to 30% by weight, more preferably from 5% to 25% by weight, and most preferably in an amount of from 10% to 20% by weight of the composition.
It has been found that the buffering action of the pH buffering components allows to reduce the conversion of hypochlorite into hypochlorous acid, one of the species which are responsible for the fabric damage and/or fabric yellowing-prevention. In other words, the pH buffering components, when added in a bleaching composition comprising a hypohalite bleach, an oligocarboxylate, a complex-facilitating co-agent and optionally a catalyst, has a further action in addition to the one of said fabric protection system, allowing thereby to further improve the fabric yellowing-prevention and/or the fabric safety of fabrics bleached with said composition.

Other optional ingredients

The bleaching compositions according to the present invention may further comprise other optional ingredients such as other surfactants on top of the surfactants described as complex-facilitating co-agents, organic or inorganic alkalis, pigments, dyes, brighteners, polymers, solvents, builders, thickening agents, perfumes, chelating agents, stabilising agents and the like and mixtures thereof.

Stabilising agents

A highly preferred optional component of the invention is a stabilising agent or mixture thereof, preferably a radical scavenger, a chelating agent or a mixture thereof. Naturally, for the purpose of the invention, the stabilizing agents have to be stable to the hypohalite bleach.
Highly preferred stabilizing agents are radical scavengers alone or in combination with a chelating agent.
Suitable radical scavengers are described in three categories. The first category of radical scavengers (i) has general formula :
wherein S is either -COO^-M⁺ or -SO₃ ^-M⁺; X, Y, Z, J, W are substituents of the benzene ring independently being either -H, -COO^-M⁺, -Cl, -Br, -SO₃ ^-M⁺, -NO₂, -OR' (with R' = linear or branched alkyl chain C₁-C₂₀), or a C₁ - C₁₀ primary and secondary alkyl groups; and M is either H or a metal.
The second category of radical scavengers (ii) are naphthalene derivatives wherein the carbon atoms in position 1 to 8 (see below figure for carbon numbering) are substituted with S, A, B, C, D, E, F, G groups and wherein: S is either -COO^-M⁺ or -SO₃ ^-M⁺ ; A, B, C, D E, F and G are independently either -H, -COO^-M⁺, -Cl, -Br, -SO₃ ^-M⁺, -NO₂, -OR' (with R' = linear or branched alkyl chain C₁-C₂₀), or a C₁ to C₁₀ primary and secondary alkyl groups; and M is H or a metal.
The third category of radical scavengers (iii) are homo or copolymers containing either as a part of the repeating unit(s) or as a side chain substituent one or more residues of the type:

wherein I, L, M, N, O, P, Q are independently either -H, -COO^-M⁺, -SO₃ ^-M⁺,-Cl, -Br, -SO₃ ^-M⁺, -NO₂, -OR' (with R' = linear or branched alkyl chain C₁-C₂₀) or a C₁ - C₁₀ primary and secondary alkyl groups; R is either -H, -COO^-M⁺,-SO₃ ^-M⁺, -Cl, -Br, -SO₃ ^-M⁺, -NO₂, -OR' (with R' = linear or branched alkyl chain C₁-C₂₀), -OH or a C₁ - C₁₀ primary and secondary alkyl groups; R₁ and R₂ are independently either -CH₂-, -CHR-, -CRR-, -CO-, -CO-O-, -CO-NH-, -O-,-CH₂CH₂O-, -N⁺(R)₂-, -(N->O)- (with R = linear or branched alkyl chain C₁-C₂₀), and M is either H or a metal.
Preferred radical scavengers are selected from the group consisting of 2,3,4,5-tetramethoxy benzoic acid; 2,3,4,5,6-pentamethoxy benzoic acid; polystyrene; polystyrene sulfonate; styrene:maleic acid copolymer; styrene:acrylic acid copolymer; styrene:ethylene glycole graft polymers; poly(ethyleneglycol) ditoluene sulfonate; poly hydroxy benzoic acid; poly hydroxy styrene; poly methyl stryrene; polystyrene divinyl benzene; poly vinyl phenol; benzoic acid; toluic acid; 4-toluene sulfonic acid; 3-nitro benzoic acid; 2-n-octyl benzoic acid; 2-n-octyl sulfonic acid; anisic acid; and mixtures thereof.
Where the pH of the bleaching compositions of the present invention is in the alkaline range, the radical scavengers of the present invention exist primarily as the ionized salt in the aqueous composition herein. The anhydrous derivatives of certain species described herein above can also be used in the present invention, e.g., pyromellitic dianhydride, phthalic anhydride, sulphthalic anhydride and the like.
Suitable chelating agents for use herein may be any of those known to those skilled in the art such as the ones selected from the group consisting of phosphonate chelating agents, phosphate chelating agents, polyfunctionally-substituted aromatic chelating agents, ethylenediamine N,N'-disuccinic acids, and mixtures thereof.
Suitable phosphonate chelating agents to be used 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 to be used 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®.
Suitable phosphate chelating agents are as follows: Phosphonic acid can be condensed in the reaction
The reaction can be repeated with any of the reactive OH groups, and phosphate ingredients are obtained which can be

linear or branched polyphosphates of structure
where R is M or
where M is a counterion, preferably alkali metal;
where 0 ≤ n+m < 500 (if n+m = 0 then the compound is phosphonic acid)
cyclic polyphosphates (also referred to as metaphosphates), of structure
where R is M or
if R is
the phosphate compound contains both cycles and branched chain, and can be referred to as an ultraphosphate;
where M is a counterion, preferably an alkali metal
where 0 ≤ n+m < 500

All such phosphate ingredients are suitable for use herein, and preferred are linear phosphate ingredients (i.e., R is M) where n is 1 (pyrophosphate) and n is 2 (tripolyphosphate (STPP)), most preferably where n is 2. The most commonly available form of this phosphate is where M is Sodium.
Phytic acid, which is a chelating agent particularly suitable for use herein, is a hexa-phosphoric acid that occurs naturally in the seeds of many cereal grains, generally in the form of the insoluble calcium-magnesium salt. It may also be derived from corn steep liquor. Commercial grade phytic acid is commercially available from J.T.Baker Co., e.g., as a 40% aqueous solution. It is intended that the present invention covers the acidic form of phytic acid as well as alkali metal salt derivatives thereof, particularly sodium or potassium salts thereof. Sodium phytate is available from Jonas Chemical Co (Brooklyn, N.Y.). In fact since the typical pH of the bleaching compositions of the present invention are in the alkaline pH range, the phytic acid component exists primarily as the ionized salt in the liquid compositions herein even if it is added in its acidic form. Mixtures of such salts of phytic acid are also covered.
Polyfunctionally-substituted aromatic chelating agents may also be useful in the bleaching 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 acid is, for instance, commercially available under the tradename ssEDDS® from Palmer Research Laboratories.
Particularly preferred chelating agents for use herein are phosphate chelating agents like sodium tripolyphosphate, sodium pyrophosphate, phytic acid, and mixtures thereof.
Typically, the bleaching compositions according to the present invention may comprise from 0.01% to 10%, preferably from 0.01% to 8% by weight, more preferably from 0.1% to 5%, and most preferably from 0.2% to 3% by weight of the total composition of a stabilising agent.

Polymers

An optional component of the bleaching compositions herein is a polymer. Naturally, for the purpose of the invention, the polymer has to be stable in the presence of the hypohalite bleach.
Suitable polymers for use are polymers comprising monomeric units selected from the group consisting of unsaturated carboxylic acids, polycarboxylic acids, sulphonic acids, phosphonic acids and mixtures thereof. Co-polymerisation of the above monomeric units among them or with other co-monomers such as styrenesulfonic acid is also suitable.
Preferred examples of such polymers are the polymers and co-polymers of monomeric units selected from the group consisting of acrylic acid, maleic acid, vinylsulphonic acid and mixtures thereof. Also suitable for use herein are the above mentioned polymers and co-polymers which are modified in order to contain other functional groups such as aminophosphonic and/or phosphonic units. More preferred polymers are selected from the group consisting of polyacrylate polymers, co-polymers of acrylic and maleic acid, co-polymers of styrene sulphonic acid and maleic acid, and mixtures thereof, preferably modified with aminophosphonic and/or phosphonic groups.
The molecular weight for these polymers and co-polymers is preferably below 100,000, most preferably between 500 and 50,000. Most suitable polymers and co-polymers for use herein will be soluble in an amount up to 0.1% by weight, in an aqueous bleaching composition comprising 5% by weight of sodium hypochlorite with its pH adjusted to 13 with sodium hydroxide.
Commercially available polymers, suitable for use herein, are the polyacrylate polymers sold under the tradename Good-Rite® from BF Goodrich, Acrysol® from Rohm & Haas, Sokalan® from BASF, Norasol® from Norso Haas. Also suitable for use herein are the co-polymers of styrene sulphonic acid and maleic acid, commercially available under the tradename Versaflex® from National Starch such as Versaflex 157, as well as Acumer® terpolymers from Rohm and Haas, in particular Acumer® 3100. Preferred commercially available polymers are the polyacrylate polymers, especially the Norasol® polyacrylate polymers and more preferred are the polyacrylate polymer Norasol® 410N (MW 10,000) and the polyacrylate polymer modified with phosphonic groups Norasol ® 440N (MW 4000) and its corresponding acid form Norasol® QR 784 (MW 4000).
A preferred polymer for use herein is a polyacrylate polymer modified with phosphonic groups commercially available under the tradename Norasol® 440N (MW 4000) and its corresponding acid form Norasol® QR 784 (MW 4000) from Norso-Haas.
Mixtures of the polymers described herein may also be used in the present invention.
Typically the bleaching compositions according to the present invention may comprise up to 10% by weight, preferably up to 1%, more preferably from 0.001% to 0.5% by weight, most preferably from 0.005% to 0.2% by weight of the total composition of a polymer.

Brighteners

The bleaching compositions according to the present invention may also comprise a brightener as an optional ingredient. Naturally, for the purpose of the invention, the brightener has to be stable in the presence of the bleach used. The brighteners may be desired herein to further enhance the whiteness performance of the bleaching compositions herein.
Brighteners are compounds which have the ability to fluoresce by absorbing ultraviolet wave-lengths of light and re-emitting visible light. Brighteners, also referred to as fluorescent whitening agent (FWA), have been extensively described in the art, see for instance EP-A-0 265 041, EP-A-0 322 564, EP-A-0 317 979 or "Fluorescent whitening agents" by A.K. Sarkar, published by MERROW, especially page 71-72.
Commercial optical brighteners which may be useful in the present invention can be classified into subgroups, which include, but are not necessarily limited to, derivatives of stilbene, pyrazoline, coumarin, carboxylic acid, methinecyanines, dibenzothiophene-5,5-dioxide, azoles, 5- and 6-membered-ring heterocycles, and other miscellaneous agents. Examples of such brighteners are disclosed in "The Production and Application of Fluorescent Brightening Agents", M. Zahradnik, Published by John Wiley & Sons, New York (1982). Further optical brighteners which may also be used in the present invention include naphthlimide, benzoxazole, benzofuran, benzimidazole and any mixtures thereof.
Examples of optical brighteners which are useful in the present bleaching compositions are those identified in U.S. Patent 4,790,856. These brighteners include the PHORWHITE® series of brighteners from Verona. Other brighteners disclosed in this reference include: Tinopal-UNPA®, Tinopal CBS® and Tinopal 5BM® available from Ciba-Geigy; Artic White CC® and Artic White CWD®; the 2-(4-styryl-phenyl)-2H-naptho[1,2-d]triazoles; 4,4'-bis(1,2,3-triazol-2-yl)-stilbenes; 4,4'-bis(styryl)bisphenyls; and the aminocoumarins.
Specific examples of brighteners useful herein include 4-methyl-7-diethylamino coumarin; 1,2-bis(-benzimidazol-2-yl)ethylene; 1,3-diphenyl-pyrazolines; 2,5-bis(benzoxazol-2-yl)thiophene; 2-styryl-naptho-[1,2-d]oxazole; 2-(stilbene-4-yl)-2H-naphtho[1,2-d]triazole, 3-phenyl-7-(isoindolinyl) coumarin; 3-methyl-7-(isoindolinyl) coumarin; 3-chloro-7-(isoindolinyl) coumarin; 4-(isoindolinyl)-4'-methylstilbene; 4-(isoindolinyl)-4'-methoxystilbene; sodium 4-(isoindolinyl)-4'-stilbenesulfonate; 4-(isoindolinyl)-4'-phenylstilbene; 4-(isoindolinyl)-3-methoxy-4'-methylstilbene; 4-(2-chloroisoindolinyl)-4'-(2-methylisoindolinyl)-2,2'-stilbenedisosulfonic acid; disodium 4,4'-diisoindolinyl-2,2'-stilbene disulfonate; 4,4'-diisoindolinyl-2,2'-stilbenedisulfonamide; disodium 4,4'-(7,8-dichloro-1-isoindolinyl)2,2-stilbenedisulfonate; disodium 4,4'-(7-chloro-1-isoindolinyl)2,2-stilbenedisulfonate; disodium 4,4'-(6-lsopropoxy-1-isoindolinyl)2,2-stilbenedisulfonate; disodium 4,4'-(7,8-diisopropyl-1-isoindolinyl)2,2-stilbenedisulfonate; disodium 4,4'-(7-butoxy-1-isoindolinyl)2,2-stilbenedisulfonate; disodium 4,4'-(6-trifluoromethyl-1-isoindolinyl)2,2-stilbenedisulfonate; disodium 4,4'-[6-(1,4,7-trioxanonyl)-1-isoindolinyl)]2,2-stilbenedisulfonate; disodium 4,4'-(7-methoxymethyl-1-isoindolinyl)2,2-stilbenedisulfonate; disodium 4,4'-(6-phenyl-1-isoindolinyl)2,2-stilbenedisulfonate; disodium 4,4'-(6-naphthyl-1-isoindolinyl)2,2-stilbenedisulfonate; disodium 4,4'-(6-methylsulfonyl-1-isoindolinyl)2,2-stilbenedisulfonate; disodium 4,4'-(7-cyano-1-isoindolinyl)2,2-stilbenedisulfonate; and disodium 4,4'-[7-(1,2,3-trihydroxypropyl)-1-isoindolinyl)]2,2-stilbenedisulfonate; disodium 4-isoindolinyl-4'-ethoxy-2,2'-stilbenedisulfonate; disodium 4-isoindolinyl-4'-methoxy-2,2'-stilbenedisulfonate; disodium 4-isoindolinyl-4'-ethoxy-2,2'-stilbenedisulfonamide; disodium 4-isoindolinyl-4'-methyl-2,2'-stilbenedisulfonamide; 4,4'-bis(4-phenyl-2H-1,2,3-triazol-2-yl)-2,2'-stilbenedisulfonic acid and mixture thereof. See also U.S. Patent 3,646,015, U.S. Patent 3,346,502 and U.S. Patent 3,393,153 for further examples of brighteners useful herein.
Indeed one of the functionally equivalent derivative salts of 4,4'-bis(4-phenyl-2H-1,2,3-triazol-2-yl)-2,2'-stilbenedisulfonic acid, namely its sodium salt is available from Mobay Chemical Corporation, a subsidiary of Bayer AG under the name Phorwite® CAN. The amine salt is available from Molay under the name Phorwite® CL solution. The potassium salt is available under the name Phorwite® BHC 766.
Other specific examples of optical brighteners useful in the present invention are those having the structural formula:
wherein R₁ is selected from anilino, N-2-bis-hydroxyethyl and NH-2-hydroxyethyl; R₂ is selected from N-2-bis-hydroxyethyl, N-2-hydroxyethyl-N-methylamino, morphilino, chloro and amino; and M is a salt-forming cation such as sodium or potassium.
When in the above formula, R₁ is anilino, R₂ is N-2-bis-hydroxyethyl and M is a cation such as sodium, the brightener is 4,4',-bis[(4-anilino-6-(N-2-bis-hydroxyethyl)-s-triazine-2-yl)amino]-2,2'-stilbenedisulfonic acid and disodium salt. This particular brightener species is commercially marketed under the tradename Tinopal-UNPA-GX by Ciba-Geigy Corporation. Tinopal-UNPA-GX is the preferred hydrophilic optical brightener useful in the detergent compositions herein.
When in the above formula, R₁ is anilino, R₂ is N-2-hydroxyethyl-N-2-methylamino and M is a cation such as sodium, the brightener is 4,4'-bis[(4-anilino-6-(N-2-hydroxyethyl-N-methylamino)-s-triazine-2-yl)amino]2,2'-stilbenedisulfonic acid disodium salt. This particular brightener species is commercially marketed under the tradename Tinopal 5BM-GX by Ciba-Geigy Corporation.
When in the above formula, R₁ is anilino, R₂ is morphilino and M is a cation such as sodium, the brightener is 4,4'-bis[(4-anilino-6-morphilino-s-triazine-2-yl)amino]2,2'-stilbenedisulfonic acid, sodium salt. This particular brightener species is commercially marketed under the tradename Tinopal AMS-GX by Ciba Geigy Corporation.
Other substituted stilbene 2,2'-disulfonic acid derivatives also include 4-4'-bis (2-2' styryl sulfonate) biphenyl, commercially available from Ciba-Geigy under the trade name Brightener 49® or other hydrophilic brighteners like for example Brightener 3® or Brightener 47®, also commercially available from Ciba-Geigy.
Further specific examples of brighteners useful in the present invention include the polycyclic oxazole derivatives such as benzo-oxazole derivatives, or mixtures thereof and particularly preferred herein the benzo-oxazole derivatives. An example of such a brightener is benzoxazole,2,2'-(thiophenaldyl)bis having the following formula C₁₈H₁₀N₂O₂S, commercially available from Ciba-Geigy under the trade name Tinopal SOP®. This brightener is almost insoluble in water, i.e., it has a solubility being lower than 1 gram per liter. Another example of such a brightener is bis(sulfobenzofuranyl)biphenyl, commercially available from Ciba-Geigy under the trade name Tinopal PLC®.
Typically the bleaching compositions according to the present invention may comprise up to 1.0%, preferably from 0.005% to 0.5%, more preferably from 0.005% to 0.3% and most preferably from 0.008% to 0.1% by weight of the total composition of a brightener.

Process of bleaching fabrics:

The present invention further encompasses a process of bleaching fabrics which comprises the step of contacting said fabrics with a bleaching composition according to the present invention comprising a hypohalite bleach, an oligocarboxylate and a complex-facilitating co-agent. In a preferred embodiment, the compositions used in said process of bleaching fabrics are hypohalite-containing, preferably hypochlorite-containing, compositions that may further comprise a catalyst, more preferably a catalyst and a pH buffering component as defined hereinbefore.
The compositions according to the present invention are preferably contacted to fabrics in a liquid form. Indeed, by "in a liquid form" it is meant herein the liquid compositions according to the present invention per se in neat or diluted form, as well as the granular or powder compositions or tablets according to the present invention that have been diluted with an appropriate solvent, typically water, before use, i.e., before being contacted to said fabrics.
The compositions according to the present invention are typically used in diluted form in a laundry operation. By "in diluted form" it is meant herein that the compositions for the bleaching of fabrics according to the present invention may be diluted by the user, preferably with water. Such dilution may occur for instance in hand laundry applications as well as by other means such as in a 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.
By "in its neat form", it is to be understood that the liquid bleaching compositions are applied directly onto the fabrics to be treated without undergoing any dilution, i.e., the liquid compositions herein are applied onto the fabrics as described herein.
More specifically, the process of bleaching fabrics according to the present invention preferably comprises the steps of first contacting said fabrics with a bleaching composition according to the present invention, then allowing said fabrics to remain in contact with said composition, for a period of time sufficient to bleach said fabrics, then rinsing said fabrics with water. If said fabrics are to be washed, i.e., with a conventional composition comprising at least one surface active agent, the washing of said fabrics with a detergent composition comprising at least one surface active agent may be conducted before the step of contacting said fabrics with said bleaching composition and/or in the step where said fabrics are contacted with said bleaching composition and/or after the step where said fabrics are contacted with the bleaching composition and before the rinsing step and/or after the rinsing step.
The bleaching composition may be used in dilute or neat form. Where it is used diluted, the bleaching composition should remain in contact with the fabric for typically 1 to 60 minutes, preferably 5 to 30 minutes. Whereas, when the bleaching composition is used in its neat form, it should remain in contact with the fabric for a much shorter time, typically 5 seconds to 30 minutes, preferably 1 minute to 10 minutes.
In a preferred embodiment of the present invention wherein the liquid bleaching composition of the present invention, is contacted to the fabrics in its neat form, it is preferred that the level of hypohalite bleach, is from 0.01% to 5%, preferably from 0.1% to 3.5%, more preferably from 0.2% to 2% and most preferably from 0.2% to 1%. Advantageously, the present invention provides liquid hypohalite bleach-containing compositions that may be applied neat onto a fabric to bleach, despite a standing prejudice against using hypochlorite-containing compositions neat on fabrics.
It is preferred to perform the bleaching processes herein before said fabrics are washed. Indeed, it has been observed that bleaching said fabrics with the compositions according to the present invention (diluted and/or neat bleaching processes) prior to washing them with a detergent composition provides superior whiteness and stain removal with less energy and detergent than if said fabrics are washed first, then bleached.
Alternatively instead of following the neat bleaching process as described herein above (pretreater application) by a rinsing step with water and/or a conventional washing step with a liquid or powder conventional detergent, the bleaching pre-treatment operation may also be followed by the diluted bleaching process as described herein before either in bucket (hand operation) or in a washing machine.

Examples

The following examples will further illustrate the present invention. The compositions are made by combining the listed ingredients in the listed proportions (weight % unless otherwise specified). The following Examples are meant to exemplify compositions used in a process according to the present invention but are not necessarily used to limit or otherwise define the scope of the present invention.

Compositions	I	II	III	IV	V	VI	VII
(weight %)
Sodium hypochlorite	5.0	5.0	5.0	2.5	2.5	5.0	5.0
Sodium hydroxide	1.3	1.3	1.3	0.7	1.4	0.7	1.4
Sodium carbonate	--	1.2	1.2	1.0	1.2	1.2	1.2
Sodium silicate	--	--	0.5	--	--	0.2	--
Sodium metaborate	--	0.5	--	--	--	--	--
Sodium 1,2,3,4,butane
tetracarboxylate	1.0	0.75	0.75	1.0	0.75	0.5	1.0
Tert-amyl alcohol	0.5	0.1	1.0	2.0	0.5	5.0	0.01
SnCl₂	--	0.1	0.2	--	0.1	--	--
ZnCl₂	--	--	--	--	0.1	--	0.1
Minors and water	----------------balance up to 100%------------------
The pH of these examples is from 8 to 14.

Compositions	VIII	IX	X	XI	XII	XIII	XIV
(weight %)
Sodium hypochlorite	5.0	5.0	5.0	2.5	2.5	5.0	5.0
Sodium hydroxide	1.3	1.3	1.3	0.7	1.4	0.7	1.4
Sodium carbonate	--	1.2	1.2	1.0	1.2	1.2	1.2
Sodium silicate	--	--	0.5	--	--	0.2	--
Sodium 1,2,3,4-butane
tetracarboxylate	1.0	1.0	0.75	1.0	0.75	--	--
Sodium 1,2,3-propane
tricarboxylate	--	--	--	--	--	1.0	1.0
C₁₂-C₁₄ dimethyl
amine oxide	0.1	0.5	1.0	2.0	5.0	0.3	0.1
TiO₂	--	--	0.2	0.1	--	0.1	--
Bismuth subcarbonate	--	0.1	--	--	0.1	--	--
Minors and water	--------------------balance up to 100%------------------
The pH of these examples is from 8 to 14.

Compositions	XX	XXI	XXII	XXIII	XXIV	XXV	XXVI
(weight %)
Sodium hypochlorite	1.0	1.0	1.0	2.5	3.5	2.5	5.0
Sodium carbonate	--	1.2	1.2	1.2	1.2	1.2	1.2
Sodium metaborate	--	--	1.5	--	--	--	--
Sodium silicate	--	--	--	--	--	0.2	--
Sodium 1,2,3,4-butane
tetracarboxylate	1.0	1.0	1.0	1.0	1.0	1.0	1.0
NaC_12/14E3S	5.0	0.1	3.0	2.0	1.0	6.0	0.3
SnCl₂	--	0.1	--	0.1	--	0.1	0.1
Minors and water	---------------------balance up to 100--------------------
Sodium hydroxide up to pH 12.

C₁₂-C₁₄ dimethyl amine oxide is commercially available from Albright & Wilson. NaC_12/14E3S is a C_12/14 ethoxylated sulphate surfactant commercially available from Albright & Wilson.
All the above bleaching compositions provide fabric safety and/or fabric yellowing-prevention benefits when used to treat fabrics.

Claims

A liquid or solid bleaching composition comprising a hypohalite bleach, a complex-facilitating co-agent and from 0.001% to 3% by weight of the total composition of an oligocarboxylate according to the formula:
wherein : n is an integer of from 0 to 20; the substituents R₁ and R₄ are independently selected from the group consisting of : -(CH₂)_pCOOH;-(CH₂)_p(CHCOOH)_qCH₃; -(CHCOOH)_qCH₃-(CH₂)_p(CHCOOH)_qCOOH; and -(CHCOOH)_qCOOH; the substituents R₂ and R₃ are independently selected from the group consisting of : hydrogen; -CH₃; -COOH;-(CH₂)_pCH₃; -(CH₂)_pCOOH; -(CH₂)_p(CHCOOH)_qCH₃; -(CHCOOH)_qCH₃;-(CH2)p(CHCOOH)qCOOH; and -(CHCOOH)qCOOH; wherein p is an integer of from 1 to 20; and wherein q is an integer of from 1 to 20.
A liquid bleaching composition according to claim 1 wherein said hypohalite bleach is an alkali metal and/or an alkaline earth metal hypochlorite.
A solid bleaching composition according to claim 1 wherein said hypohalite bleach is : an alkali metal or alkaline earth metal hypochlorite; chlorinated trisodium phosphate dodecahydrate; potassium dichloroisocyanurate; sodium dichloroisocyanurate; potassium trichlorocyanurate; sodium trichlorocyanurate; or a mixture thereof.
A bleaching composition according to any of the preceding claims wherein said hypohalite bleach, based on active halide, is present in an amount of from 0.01% to 20% by weight by weight of the liquid composition or in an amount of from 20% to 95% by weight by weight of the solid composition.
A bleaching composition according to any of the preceding claims wherein in said oligocarboxylate n is an integer of from 0 to 10, p and q independently are integers of from 1 to 10.
A bleaching composition according to any of the preceding claims wherein in said oligocarboxylate the substituents R₁ and R₄ independently are-(CH₂)_pCOOH, the substituents R₂ and R₃ independently are hydrogen,-CH₃, -(CH₂)_pCOOH or -COOH and wherein p is an integer of from 1 to 10.
A bleaching composition according to any of the preceding claims wherein said oligocarboxylate is sodium 1,2,3,4-butane tetracarboxylate.
A bleaching composition according to any of the preceding claims wherein said complex-facilitating co-agent has at least one functional group selected from the group consisting of an alkoxy group, an amine oxide group, a positively charged nitrogen ion, a betaine or a sulfobetaine moiety and a hydroxy group.
A bleaching composition according to any of the preceding claims wherein said complex-facilitating co-agent is selected from the group consisting of: alkoxylated surfactants; amine oxide surfactants; quaternary ammonium surfactants; betaine and sulfobetaine surfactants; tertiary alcohols and polyalcohols; and mixtures thereof.
A bleaching composition according to claim 9 wherein said alkoxylated surfactant is selected from the group consisting of non-capped or capped alkoxylated nonionic surfactants, alkyl alkoxylated sulphates, alkyl alkoxylated sulphonates, alkyl alkoxylated carboxylates and alkyl alkoxylated methylcarboxylates and mixtures thereof.
A bleaching composition according to claim 9 wherein said tertiary alcohols and polyalcohols are according to the formula :
wherein : R₁, R₂ and R₃ are independently linear or branched, saturated or unsaturated hydrocarbon chains of from 1 to 30, carbon atoms optionally comprising one or more C₅ to C₇ aromatic or aliphatic ring structures; and m, m', m" n, n', n", o, o' and o" are independently integers of from 0 to 1000.
A bleaching composition according to any of the preceding claims wherein said complex-facilitating co-agent is present in an amount of from 0.01% to 20% by weight of the liquid composition or in an amount of from 0.01% to 40% by weight of the solid composition.
A bleaching composition according to any of the preceding claims which further comprises up to 2% by weight of the liquid composition or up to 5% by weight of the solid composition of a catalyst.
A bleaching composition according to claim 13 wherein said catalyst is according to the formula X_aM wherein X is Cl, Br, O or OH, wherein M is zinc, tin, titanium, bismuth, aluminium, magnesium, cobalt, germanium or antimony, and wherein a is an integer of from 1 to 6 (depending on the oxidation state of M) or bismuth subcarbonate, subnitrate or a mixture thereof.
A bleaching composition according to any of the preceding claims, wherein said composition further comprises a pH buffering component
A bleaching composition according to claim 15, wherein said pH buffering component is selected from the group consisting of alkali metal salts of carbonates, polycarbonates, sesquicarbonates, silicates, polysilicates, boron salts, boric acid, phosphonates, stannates, alluminates and mixtures thereof and present in an amount of from 0.5% to 9% by weight of the liquid composition or in an amount of from 3% to 30% by weight of the solid composition.
A bleaching composition according to any of the preceding claims, wherein said bleaching composition further comprises an alkalinity source.
A process of bleaching fabrics which comprises the step of contacting said fabrics with a bleaching composition according to any of the preceding claims, in its diluted form at a dilution level with water up to 500 times.
A process of bleaching fabrics according to claim 18 which comprises the additional subsequent steps of:

allowing said fabrics to remain in contact with said bleaching composition for a period of time sufficient to bleach said fabrics;

then rinsing said fabrics in water to remove said bleaching composition.
A process according to any of the claims 18 or 19 wherein said fabrics are washed with a detergent composition comprising at least one surface active agent before and/or during the contacting with the bleaching composition and/or after the rinsing when said bleaching composition has been removed.
A process of bleaching a fabric which comprises the step of contacting said fabric with a liquid bleaching composition according to any of claims 1 to 17, in its neat form, allowing said fabric to remain in contact with said bleaching composition for a period of time sufficient to bleach said fabric, and then rinsing said fabric in water to remove said bleaching composition.
A process according to claim 21 wherein said fabric is washed with a detergent composition comprising at least one surface active agent before the step of contacting said fabric with said bleaching composition and/or after the step of rinsing wherein said bleaching composition has been removed.
The use of a complex-facilitating co-agent in a bleaching composition comprising a hypohalite bleach and an oligocarboxylate, whereby fabric yellowing-prevention and/or fabric safety benefits are provided.