EP1966362B1 - Improving the stability of detergents containing hypochlorite - Google Patents

Abstract

Use of cyclodextrin for the stabilization of optical brightener in aqueous liquid detergent containing alkali hypochlorite. An independent claim is also included for an aqueous liquid bleaching agent containing alkali hypochlorite, optical brightener and cyclodextrin.

Description

The present invention relates to the stabilization of hypochlorite-containing liquid detergents which contain optical brighteners.

Sodium hypochlorite is known to be a highly effective bleaching agent and has been used for a long time, optionally with soaps and / or synthetic surfactants, to remove stains and all sorts of soils from laundry to textiles as well as hard surface cleaning. It is normally sold in concentrations of about 2% to 10% by weight in water for household use

Liquid detergent formulations or equivalent preparations of hard surface cleaners containing hypochlorite as a bleaching component are susceptible to loss of activity upon prolonged storage, especially because of the then-depleting hypochlorite. Among the ingredients that are desirable from an application point of view or for aesthetic reasons in detergents and cleaners include, in addition to the performance of such agents crucial influencing agents, among which in particular the hypochlorite may be mentioned, also active ingredients, which rather the visual appearance of the so affect treated textiles. Here are primarily optical brighteners to name, which raise during the washing process on the fibers of the textile material. These compounds are able to absorb light and emit light of shorter wavelength. In the absorption of red and yellow-toned light and the emission of blue to ultraviolet light results in the sum of an increase in the intensity of perceived as white light, so that a correspondingly treated textile looks optically lighter. For white laundry, this is a very desirable effect; Detergents intended for use in washing colored textiles generally do not contain optical brighteners. Optical brighteners are easily oxidatively attacked by hypochlorite, so that corresponding agents, both containing, after storage, in addition to the resulting loss of the bleaching agent also for the optical White impression co-responsible active ingredient of the optical brightener is no longer or at least not fully available.

In the international patent application WO 99/15616 It is proposed to add free-radical scavengers to hypohalite-containing bleaching agents containing optical brighteners to stabilize the optical brighteners. US 3,393,153 discloses liquid bleaching compositions, and EP 1 462 512 discloses compositions containing cyclodextrin.

Surprisingly, it has now been found that certain compounds which are not radical scavengers contribute very effectively to the stabilization of optical brighteners in hypochlorite-containing liquids.

The present invention is the use of cyclodextrin for stabilizing optical brighteners in aqueous liquid detergents containing alkali metal hypochlorite.

The use of cyclodextrins in the field of detergents and cleaners is known from the prior art. In the international patent application WO 94/10280 a detergent is described which contains at least one cyclodextrin or cyclodextrin derivative as a cleaning-active component. The agent described therein is used in particular for removing oils, fats, aliphatic and aromatic hydrocarbons, acids, esters and ethers from arbitrary surfaces.

In the international patent application WO 93/05136 discloses a process for the preparation of solid particles from water-prone materials in which particulate complexes of cyclodextrins and perfumes are provided with a protective sheath.

Cyclodextrins, also called cycloglucans, are formed in the degradation of starch by Bacillus macerans or B. circulans under the action of cyclodextrin glycosyltransferase. The cyclodextrins consist of ring-shaped α-1,4-linked glucose units, usually of 6, 7 or 8 glucose units; these are referred to as α-, β- or γ-cyclodextrin. The use of cyclodextrins or their derivatives as active cleaning component is used, for example, in the international patent application WO 94/10280 described. Surprisingly, it has now been found that on addition of cyclodextrins to hypochlorite-containing liquid agents, the stability of optical brighteners contained in these agents is increased and also that the hypochlorite is degraded less rapidly on storage than is the case without this addition.

A second object of the invention is an aqueous liquid bleach or bleaching detergent containing alkali hypochlorite and optical brightener, which is characterized in that it additionally contains cyclodextrin.

Normally, it is sufficient if more than 0 wt.% To about 1 wt.%, In particular about 0.01 wt.% To about 0.5 wt.%, Of cyclodextrin is included in the liquid agent to be stabilized is.

The agent according to the invention may contain any desired cyclodextrins, for example .alpha.-, .beta.- or .gamma.-cyclodextrin. Preference is given to the use of β-cyclodextrin.

The optical brightener stabilized according to the invention is preferably selected from a compound according to one of the following formulas (I) to (VIII) or mixtures thereof, wherein the compounds with trans-configured C =C double bond shown are also present at least partially in cis configuration can:

R¹

Wasserstoff, -SO₃M, -OR¹³, -CN, -Cl, -COOR¹³, -CON(R¹³)₂

R² und R³

unabhängig voneinander Wasserstoff, -R¹³ oder -Ar,

R⁴ und R⁵

unabhängig voneinander -OH, -Cl, -NH₂, -OR¹³, -O-Ar, -NHR¹³, -N(R¹³)₂, -NR¹³R¹⁴, -N(R¹⁴)₂, -NH-Ar, eine Morpholino-Gruppe, -S-R¹³ oder -S-Ar,

R⁶

Wasserstoff, -Cl oder -SO₃M,

R⁷

-CN, -SO₃M, -S-R¹³ oder -S-Ar,

R⁸

Wasserstoff, -R¹³, -Cl oder -SO₃M,

R⁹ und R¹⁰

unabhängig voneinander Wasserstoff, -R¹³, -Cl, -SO₃M oder -OR¹³,

R¹¹

Wasserstoff oder -R¹³,

R¹²

Wasserstoff, -R¹³, -CN, Cl, -COOR¹³, -CON(R¹³)₂, -Ar oder -O-Ar,

R¹³

eine verzweigte oder unverzweigte C₁- bis C₄-Alkylgruppe

R¹⁴

eine verzweigte oder unverzweigte C₁- bis C₄-Hydroxyalkylgruppe,

Ar

eine gegebenenfalls mit -R¹³, -Cl, -SO₃M oder -OR¹³ substituierte Phenyl-, Naphthyl-, Pyrindinyl-, Pyridazinyl-, Pyrimidinyl-, Pyrazinyl-, Triazinyl-, Indolyl-, Anthracenyl-, Phenanthrenyl- oder Benzonaphthylgruppe,

M

Wasserstoff, Na, K, Ca, Mg, Ammonium, mono-, di-, tri- oder tetra-R¹³- substituiertes Ammonium, mono-, di-, tri- oder tetra-R¹⁴-substituiertes Ammonium oder mit einer Mischung aus R¹³ und R¹⁴ mono-, di-, tri- oder tetra-substituiertes Ammonium.

In these mean

R ¹

Hydrogen, -SO ₃ M, -OR ¹³ , -CN, -Cl, -COOR ¹³ , -CON (R ¹³ ) ₂

R ² and R ³

independently of one another hydrogen, -R ¹³ or -Ar,

R ⁴ and R ⁵

independently of one another -OH, -Cl, -NH ₂ , -OR ¹³ , -O-Ar, -NHR ¹³ , -N (R ¹³ ) ₂ , -NR ¹³ R ¹⁴ , -N (R ¹⁴ ) ₂ , -NH- Ar, a morpholino group, -SR ¹³ or -S-Ar,

R ⁶

Hydrogen, -Cl or -SO ₃ M,

R ⁷

-CN, -SO ₃ M, -SR ¹³ or -S-Ar,

R ⁸

Hydrogen, -R ¹³ , -Cl or -SO ₃ M,

R ⁹ and R ¹⁰

independently of one another hydrogen, -R ¹³ , -Cl, -SO ₃ M or -OR ¹³ ,

R ¹¹

Hydrogen or -R ¹³ ,

R ¹²

Hydrogen, -R ¹³ , -CN, Cl, -COOR ¹³ , -CON (R ¹³ ) ₂ , -Ar or -O-Ar,

R ¹³

a branched or unbranched C ₁ - to C ₄ alkyl group

R ¹⁴

a branched or unbranched C ₁ - to C ₄ -hydroxyalkyl group,

Ar

an optionally substituted with -R ¹³ , -Cl, -SO ₃ M or -OR ¹³ substituted phenyl, naphthyl, pyrindinyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, indolyl, anthracenyl, phenanthrenyl or Benzonaphthylgruppe .

M

Hydrogen, Na, K, Ca, Mg, ammonium, mono-, di-, tri- or tetra-R ¹³ -substituted ammonium, mono-, di-, tri- or tetra-R ¹⁴ -substituted ammonium or with a mixture of R ¹³ and R ¹⁴ mono-, di-, tri- or tetra-substituted ammonium.

Particular preference is given to using optical brighteners which correspond to the formulas (I) or (II). For example, the compound according to formula (I) with R ¹ = M = H under the name Tinopal® CBS-X by Ciba-Geigy and the compound according to formula (II) with R ² = M = H, R ³ = phenyl under the Name Optiblanc® BRB available from 3V Sigma.

Optical brighteners are usually present only in small amounts, for example from 10 ppm to 0.5 wt .-%, in detergents or bleaches.

Preparations according to the invention are particularly suitable and very effective as bleaching agents or bleaching detergents for white textiles. An agent of the present invention is effective against a variety of stains, including greasy soils such as sebum, makeup, or lipstick, enzymatically removable soils such as blood, grass or cocoa, and bleachable soils such as wine, coffee or tea, even after aging of the composition means if it has been stored for a long time after its production.

Another advantage of bleaches according to the present invention is that they are suitable for bleaching textiles of various materials, including those of natural fibers such as cotton or linen, but also those of synthetic material, such as synthetic polymer fibers, and also of corresponding ones mixed fabrics.

A liquid composition according to the present invention is advantageously applied to the textiles to be cleaned in diluted form, for example when it is used in manual or machine washing of textiles as a washing additive or as a detergent alone, but it can additionally or alternatively also undiluted to the textile be applied, for example, as a liquid pretreatment agent or stain remover.

A bleaching agent in the form of hypochlorite is an essential component of the compositions according to the invention. Bleaches per se are well-known components of detergent and cleaner compositions and, in particular, are also successful in controlling mildew and mildew and in disinfecting. Although other alkali metal hypochlorites, such as potassium hypochlorite, are useful, it is preferred to employ sodium hypochlorite in minerals stabilized in accordance with the present invention. Commercially available aqueous sodium hypochlorite solutions often contain considerable amounts of chloride salts. These can readily for the production according to the invention Means are used, so that one does not necessarily rely on the use of high purity NaOCl. In a preferred embodiment of the invention, the compositions contain 0.5% by weight to 5% by weight, in particular 1% by weight to 4% by weight, of alkali metal hypochlorite.

The stabilized agents according to the invention are normally alkaline and may contain for this purpose about 0.1 wt .-% to 2 wt .-%, in particular 0.1 wt .-% to 1.1 wt .-% alkali metal hydroxide. The preferred alkali hydroxide is sodium hydroxide, and also the alkali salts mentioned in connection with the other ingredients of the compositions are preferably the sodium salts.

in der R¹⁴ eine Alkyl- oder Alkenylgruppe mit 6 bis 22 Kohlenstoffatomen oder eine Gruppe R¹⁷CO-NH-(CH₂)_n- ist, R¹⁵ Wasserstoff oder eine Alkylgruppe mit 1 bis 4 Kohlenstoffatomen ist, R¹⁶ Wasserstoff oder eine Alkylgruppe mit 1 bis 4 Kohlenstoffatomen ist, R¹⁷ eine Alkyl- oder Alkenylgruppe mit 6 bis 22 Kohlenstoffatomen ist, m eine Zahl von 1 bis 6 und n eine Zahl von 1 bis 3 ist. Beispiele für besonders geeignete Vertreter dieser Klasse von Tensiden umfassen C_12-18-Alkyldimethylbetain, kommerziell erhältlich als Kokosnußbetain, und C_10-16-Alkyldimethylbetain, kommerziell erhältlich als Laurylbetain. Eine weitere Klasse besonders bevorzugter Tenside sind die Alkylethersulfate, die durch Umsetzung von Alkoholen (vorzugsweise mit 6 bis 22 Kohlenstoffatomen) mit Alkylenoxiden, insbesondere Ethylenoxid, und anschließende Sulfatierung und Neutralisation erhältlich sind, insbesondere ein mit 2 Equivalenten Ethylenoxid alkoxyliertes C_12-14-Fettalkoholethersulfat. In den Ethersulfaten ist das korrespondierende Kation vorzugsweise Natrium. Tenside sind, falls anwesend, vorzugsweise in Mengen bis zu 20 Gew.-%, insbesondere von 0,1 Gew.-% bis 15 Gew.-% in erfindungsgemäß stabilisierten Mitteln enthalten.The formulations may contain surfactants that are stable in the presence of the hypochlorite. Preference is given to betaines, in particular those of the general formula IX,

wherein R ^{14 is} an alkyl or alkenyl group having 6 to 22 carbon atoms or a group R ^{17 is} CO-NH- (CH ₂ ) _n -, R ^{15 is} hydrogen or an alkyl group having 1 to 4 carbon atoms, R ^{16 is} hydrogen or an alkyl group with 1 to 4 carbon atoms, R ^{17 is} an alkyl or alkenyl group having 6 to 22 carbon atoms, m is a number from 1 to 6 and n is a number from 1 to 3. Examples of particularly suitable members of this class of surfactants include C _12-18 alkyl dimethyl betaine, commercially available as coconut betaine, and C _10-16 alkyl dimethyl betaine, commercially available as lauryl betaine. Another class of particularly preferred surfactants are the alkyl ether sulfates obtainable by reacting alcohols (preferably having 6 to 22 carbon atoms) with alkylene oxides, especially ethylene oxide, followed by sulfation and neutralization, especially a C _12-14 fatty alcohol ether sulfate alkoxylated with 2 equivalents of ethylene oxide , In the ether sulfates, the corresponding cation is preferred Sodium. Surfactants, if present, are preferably contained in amounts of up to 20% by weight, in particular of 0.1% by weight to 15% by weight, of stabilizers in accordance with the invention.

in der R¹⁸ Wasserstoff, eine Gruppe -(CH₂)_x(CHCH₃)_y-NH₂->O oder ein Alkalimetall ist, x eine Zahl von 1 bis 4 und y 0 oder 1 ist. Unter den besonders bevorzugten Phosphonsäuren ist Diethylentriamin-penta-methylenphosphonsäure und das Aminoxid auf der Basis der Aminotrimethylenphosphonsäure. Vorzugsweise sind 0,01 Gew.-% bis 2 Gew.-% solcher Sequestriermittel vorhanden.The compositions may additionally contain sequestering agents, preferably aminoalkylphosphonic acids, alkylphosphonic acids and alkylphosphonic acids having at least one amine oxide substituent on the alkyl group, referred to herein as amine oxide phosphonic acids, polyacrylic acids and / or polyoxyacids containing phosphono groups which may also be in the form of their alkali metal salts. The incorporation of such complexing leads surprisingly to particularly good stability of the hypochlorite. Amine oxide phosphonic acids are normally prepared by oxidation of corresponding aminoalkyl phosphonic acids. They preferably belong to the group of compounds according to general formula (X),

in which R ^{18 is} hydrogen, a group - (CH ₂ ) _x (CHCH ₃ ) _y -NH ₂ -> O or an alkali metal, x is a number from 1 to 4 and y is 0 or 1. Among the particularly preferred phosphonic acids is diethylene triamine penta-methylene phosphonic acid and the amine oxide based on aminotrimethylene phosphonic acid. Preferably, from 0.01% to 2% by weight of such sequestering agents are present.

In addition to the constituents mentioned, the preparations stabilized according to the invention may contain small amounts of pH-buffering substances and / or one or more pale-stable dyes or fragrances. The optional perfume component is preferably of higher relative volatility than the ingredients optionally responsible for a bleaching odor. Preferably, the agents contain more than 0 wt .-% to about 0.01 wt .-%, in particular about 0.001 wt .-% to about 0.008 wt .-% of colored, in particular blue and / or green, metal pigment. Among them, complex compounds of nickel, cobalt, cuprous, iron and / or manganese are preferred; particularly preferred are copper phthalocyanine dyes. The stability of both the colored metal pigment and the alkali hypochlorite is enhanced by the presence of alkali iodide. Preferably, therefore, more than 0 wt .-% to about 0.01 wt .-%, in particular about 0.001 wt .-% to about 0.006 wt .-% alkali metal iodide, in particular potassium iodide present in inventive compositions. Useful pH buffering ingredients are preferably selected from the alkali carbonates, polycarbonates, sesquicarbonates, silicates, polysilicates, borates, phosphates, stannates, aluminates and mixtures thereof, the preferred alkali metals being sodium and potassium. The starting materials for the preparation of, for example, the hypohalite bleach may contain by-products, for example, carbonate, which may result in a content of such by-products in the compositions of optionally up to 0.4% by weight.

The aqueous compositions according to the invention normally have viscosities in the range from about 25 mPa.s to 1500 mPa.s, in particular from 50 mPa.s to 1100 mPa.s.

A composition of the present invention may be used, in dilute or undiluted form, to remove soils and stains from fabrics by allowing the composition and fabric to contact one another over a period of time sufficient to bleach the fabric, and thereafter the fabric rinsed with water. Alternatively, or alternatively to rinsing with water, the textile can also be washed using an agent according to the invention by hand or in a mechanical washing process in which an agent according to the invention is metered into a conventional washing machine.

example

For an aqueous composition containing 1.43 mmol / l NaOCl, 8 10 ^-4 mmol / l Tinopal® CBS-X, and 5 mmol / l β-cyclodextrin, the fluorescence intensity of the optical brightener after storage for 1 hour was 20%. higher than an otherwise identical composition lacking the β-cyclodextrin and stored under the same conditions.

Replacing this optical brightener with 1.5 10 ^-4 mmol / L Hostalux® PCNX, the value was 21% higher than the composition lacking the β-cyclodextrin.

Replacing this optical brightener with 7.5 10 ^-4 mmol / l Optiblanc® BRB, the value was 54% higher than the composition lacking the β-cyclodextrin.

Claims (9)

1. Use of cyclodextrin for stabilizing optical brighteners in aqueous liquid laundry detergents which contain alkali metal hypochlorite.
2. The use as claimed in claim 1, characterized in that the cyclodextrin is β-cyclodextrin.
3. The use as claimed in claim 1 or claim 2, characterized in that the composition contains more than 0 wt.% up to 0.5 wt.%, in particular 0.01 wt.% to 0.1 wt.%, of cyclodextrin.
4. The use as claimed in any one of claims 1 to 3, characterized in that the optical brightener is selected from a compound according to one of the following formulae (I) to (VIII) or mixtures thereof,

   

   

   

   

   

   

   

   

   in which

   R¹ means hydrogen, -SO₃M, -OR¹³, -CN, -Cl, -COOR¹³, -CON(R¹³)₂

   R² and R³ mutually independently mean hydrogen, -R¹³ or -Ar,

   R⁴ and R⁵ mutually independently mean -OH, -Cl, -NH₂, -OR¹³, -O-Ar, -NHR¹³, -N(R¹³)₂, -NR¹³R¹⁴, -N(R¹⁴)₂, -NH-Ar, a morpholino group, -S-R¹³ or -S-Ar,

   R⁶ means hydrogen, -Cl or -SO₃M,

   R⁷ means -CN, -SO₃M, -S-R¹³ or -S-Ar,

   R⁸ means hydrogen, -R¹³, -Cl or -SO₃M,

   R⁹ and R¹⁰ mutually independently mean hydrogen, -R¹³, -Cl, -SO₃M or -OR¹³,

   R¹¹ means hydrogen or -R¹³,

   R¹² means hydrogen, -R¹³, -CN, Cl, -COOR¹³, -CON(R¹³)₂, -Ar or -O-Ar,

   R¹³ means a branched or unbranched C₁ to C₄ alkyl group

   R¹⁴ means a branched or unbranched C₁ to C₄ hydroxyalkyl group,

   Ar means a phenyl, naphthyl, pyrindinyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, indolyl, anthracenyl, phenanthrenyl or benzonaphthyl group optionally substituted with -R¹³, -Cl, -SO₃M or -OR¹³,

   M means hydrogen, Na, K, Ca, Mg, ammonium, mono-, di-, tri- or tetra-R¹³-substituted ammonium, mono-, di-, tri- or tetra-R¹⁴-substituted ammonium or ammonium mono-, di-, tri- or tetra-substituted with a mixture of R¹³ and R¹⁴.
5. The use as claimed in any one of claims 1 to 4, characterized in that the composition contains 0.5 wt.% to 5 wt.% of alkali metal hypochlorite, in particular sodium hypochlorite.
6. The use as claimed in any one of claims 1 to 5, characterized in that the composition contains up to 20 wt.% of bleach-stable surfactant, in particular betaine and/or alkyl ether sulfate.
7. An aqueous liquid bleaching agent containing alkali metal hypochlorite and optical brightener, characterized in that it additionally contains cyclodextrin.
8. The agent as claimed in claim 7, characterized in that the optical brightener is selected from a compound according to one of the formulae (I) to (VIII) or mixtures thereof.
9. The agent as claimed in claim 7 or claim 8, characterized in that it contains 10 ppm to 0.5 wt.% of optical brightener.