SK24097A3 - Detergent compositions - Google Patents

Abstract

A particulate detergent composition containing more than 5 wt.% of C8-20 primary alcohol sulphate and/or at least 8 wt.% of an ethoxylated C8-20 alcohol nonionic surfactant and/or more than 15 wt.% of total non-soap organic surfactant, and a builder system containing alkali metal aluminosilicate, also comprises from 0.01 to 5 wt.% of an antioxidant, preferably a sterically hindered phenol, more preferably butylated hydroxytoluene or butylated hydroxyanisole. The composition exhibits improved stability of the surfactant system on bulk storage and handling.

Description

Technical field

The invention relates to particulate detergent compositions containing high levels of high-performance organic surfactants, and in particular compositions comprising a primary alcohol sulfate or ethoxylated alcohol nonionic surfactants, or both. The compositions exhibit increased stability due to the presence of low levels of antioxidants.

BACKGROUND OF THE INVENTION

EP 283 252B and EP 320219B (Procter & Gambia) disclose particulate detergent compositions in which an antioxidant is incorporated in bleach activator granules to enhance the stability of the bleach activator.

Various particulate detergent compositions containing antioxidants are also disclosed in JP 50 502A / JP 77 003 730B, JP 50 151 905A / JP 78 028 163B and JP 57 128 798A / JP 84 012 720B (Lion) and JP 73 008 324B (Daiichi) Kogyo Seijaku KK). The gain is reduced odor and discoloration when stored.

It has now been found that in particulate detergent compositions having high levels of surfactant content and high performance surfactants, especially those containing primary alcohol sulfate and / or ethoxylated nonionic surfactants, improved stability of the surfactant system can be achieved by incorporation of antioxidants, especially sterically hindered phenols. The increased protective margin thus achieved facilitates the industrial handling and overall storage of these high-activity products, thereby providing increased processing flexibility.

SUMMARY OF THE INVENTION

Accordingly, the invention provides a particulate detergent composition comprising (i) an organic surfactant system comprising anionic and / or nonionic non-soap surfactants, the composition comprising more than 5% by weight of a primary alcohol Cg_20 sulfate and / or at least 8% by weight of ethoxylated Cg_20 an alcoholic nonionic surfactant and / or more than 15% by weight total non-soap organic surfactant; (ii) an alkali metal aluminosilicate-containing detergent system; (iii) from 0.01 to 5% by weight antioxidant; (iv) optionally other detergent ingredients % to 100% by weight, all percentages based on the total mixture.

Surface-active system

The composition according to the invention comprises a high level of non-soap organic surfactant, preferably 15% by weight or more, preferably from 15 to 25% by weight. However, as indicated below, some compositions containing total surfactant levels below 15% by weight are also within the scope of this invention.

The surfactants may be selected from anionic, cationic, nonionic, amphoteric and zwitterionic detergent actives and mixtures thereof. Many suitable detergent active agents are available and are fully described in the literature, for example in Surface Active Agents and Detergents, Volumes I and II, by Schwartz, Perry and Berch.

Anionic surfactants are well known to those skilled in the art. Examples include alkylbenzenesulfonates, especially sodium linear alkylbenzenesulfonates having an alkyl chain length of C 8 -C 14; primary and secondary alkyl sulphates, especially C8-C5 primary alkyl sulphates; alkyl ether; olefin sulphonates; alkyl xylene sulphonates; dialkyl; and fatty acid sulfonate esters. Sodium salts are generally preferred.

Nonionic surfactants which may be used include the ethoxylates of primary and secondary alcohols, especially C8-C20 aliphatic alcohols ethoxylated with an average of 1 to 20 moles of ethylene oxide per mole of alcohol, more preferably primary and secondary C12-C20 alcohols ethoxylated on average with 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkyl polyglycosides, glycerol monoethers, lactobionamides and polyhydroxyamides (glucamide).

The invention is particularly applicable to compositions comprising a surfactant system comprising a C 1-20 primary alcohol sulfate, an ethoxylated nonionic C 1-20 alcohol surfactant, or both. Preferred compositions of the present invention comprise more than 5% by weight of a primary alcohol C 8-20 salt, and / or at least 8%, preferably 10% by weight, of an ethoxylated nonionic C 8-20 alcohol surfactant. When one or both of these conditions are met, the total level of the non-soap surfactant in the composition of the present invention need not be greater than 15% by weight, but is preferably at least 10% by weight and more preferably at least 12% by weight.

A class of preferred compositions of the invention includes compositions containing more than 5% by weight of the total Cg-20 primary alcohol sulfate product, optionally in conjunction with an ethoxylated nonionic Cg-20 alcohol surfactant.

Preferred compositions may contain at least 8% by weight, more preferably at least 10% by weight, of the ethoxylated nonionic surfactant, and preferably the ratio of primary alcohol sulphate to ethoxylated nonionic sulphate may be less than 1: 1. However, compositions containing minor proportions of nonionic surfactant, for example those containing other anionic surfactants, are also within the scope of this invention.

Another class of preferred compositions of the invention which also contain at least 8% by weight and more preferably at least 10% by weight of ethoxylated nonionic surfactant are those in which the non-soap surfactant system consists wholly or substantially entirely of the nonionic surfactant.

The compositions of the invention may also contain a fatty acid soap. However, if the limit is at least 15% by weight of the total surfactant, it does not include any fatty acid soap.

System of detergent ingredients

The compositions of the present invention comprise an alkali metal aluminosilicate as the detergent component, either alone or in combination with one or more additional detergent components.

The total amount of detergent component in the compositions may suitably range from 5 to 80% by weight, preferably from 10 to 60% by weight.

An essential component of the composition according to the invention is the detergent component of an alkali metal aluminosilicate, preferably sodium. Sodium aluminosilicates can generally be incorporated in amounts of from 10 to 70% by weight (anhydrous basis), preferably from 25 to 50% by weight.

The alkali metal aluminosilicates may be either crystalline or amorphous or mixtures thereof having the general formula:

0.8-1.5 Na ₂ O.Al ₂ O ₃ . 0.8-6 Si0 ₂

These materials contain bound water and are intended to have a calcium exchange capacity of at least 50 mg CaO / g. Preferred sodium aluminosilicates contain 1.5 to 3.5 SiO 2 units (in the above formula). Both amorphous and crystalline material can be prepared readily by reaction between sodium silicate and sodium aluminate, as is amply described in the literature.

Suitable crystalline sodium aluminosilicates as ion exchange detergent ingredients are described, for example, in GB 1 429 143 (Procter & Gambia). Preferred sodium aluminosilicates of this type are the well-known commercially available zeolites A and X, and mixtures thereof.

The zeolite may be a commercially available zeolite 4A, at the same time widely used in laundry detergent powders. However, according to a preferred embodiment of the invention, the zeolite component incorporated in the compositions of the invention is maximum aluminum zeolite P (zeolite MAP) as described and claimed in EP 384 070A (Unilever). Zeolite MAP is defined as an alkali metal aluminosilicate of the zeolite P type with a silicon to aluminum ratio not exceeding 1.33, preferably in the range of 0.90 to 1.33, and more preferably in the range of 0.90 to 1.20.

Particularly preferred is a zeolite MAP having a silicon to aluminum ratio not exceeding 1.07, more preferably about 1.00. The calcium binding capacity of zeolite MAP is generally at least 150 mg CaO per gram of anhydrous material.

This zeolite is preferably used in conjunction with an additional detergent component. Additional organic detergent builders that may be present include polycarboxylate polymers such as polyacrylates, acrylate / maleate copolymers and acryphosphinates; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, mono-, di-, and trisuccinates of glycerol, carboxymethyloxy succinates, carboxymethyloxy malonates, dipicolinates, hydroxyethyliminodiacetates, alkyl and alkenyl malonates and succinates; and salts of sulfonated fatty acids. This list is not intended to be exhaustive.

Particularly preferred additional detergent ingredients are citrates, suitably used in amounts of from 5 to 30% by weight, preferably from 10 to 25% by weight; and acrylic polymers, more particularly acrylate / maleate copolymers, suitably used in amounts of from 0.5 to 15% by weight, preferably from 1 to% by weight.

The compositions of the invention may also contain lamellar crystalline sodium silicates having the composition ^N 2 Si _x O _{2 + 1} . yH ₂ O wherein M represents sodium or hydrogen, preferably sodium; x is a number from 1.9 to 4; and y is a number from 0 to 20.

These materials are described in US 4,664,839, US 4,728,443 and US 4,820,439 (Hoechst AG). They are crystalline materials and can be easily characterized by their X-ray diffraction patterns. Compared to amorphous silicates, these are significantly better calcium and magnesium ion binding agents.

Preferred materials are those in which x = 2, i. compounds of the formula

NaMSi ₂ C> 5. yH ₂ O

Natural and synthetic materials of this formula are also of interest, a synthetic material known as Na-SKS-6 is particularly preferred. This material is commercially available from Hoechst AG; its preparation is described and defined in terms of its X-ray diffraction pattern, in the aforementioned US 4,664,839.

antioxidant

An antioxidant is a material capable of retarding the oxidation of the surfactant system of the composition at elevated temperatures, e.g., above 100 ° C.

The antioxidant is preferably present in an amount of from 0.01 to 2% by weight, more preferably from 0.05 to 1% by weight, and more particularly from 0.1 to 0.5% by weight.

One class of preferred antioxidants consists of sterically encapsulated phenols.

Suitable antioxidants include the following:

(i) butylated hydroxytoluene (BHT), also known as 2,6-di-tert-butyl-p-cresol;

(ii) butylated hydroxyanisole (BHA), also known as (1,1-dimethylethyl-4-methoxyphenol);

(iii) tert-butylhydroquinone (TBHQ), also known as 1,4-benzenediol.

Optional metal ion sequestrant

Advantageously, the compositions of the invention may also contain a transition metal ion sequestrant.

Preferred sequestrants include aminopolycarboxylates, for example ethylenediaminetetraacetic acid or salts thereof; or aminopolyphosphonates such as ethylenediaminetetramethylenephosphonic acid (ETDMP) or its salts (Dequest (Trade Mark) 2041 and 2047 ex Monsanto) or higher phosphonates such as diethylenetriaminepentamethylenephosphonic acid (DETPMP) or its salts (Dequest 20).

Such phosphonates are conventionally incorporated into detergent compositions containing peroxy bleaching agents such as bleach stabilizers; however, in the context of the present invention, sequestrants are preferably present both in the presence and absence of the bleaching system.

Optional whitening system

The compositions of the present invention may optionally contain a bleaching system. However, the invention does not concern bleaching stability and is equally applicable to non-bleaching compositions.

Suitable peroxygen bleaches include organic peroxides, and inorganic peroxy salts such as alkali metal perborates, percarbonates, perphosphates, peroxy silicates, and persulfates. Preferred inorganic peroxy salts are sodium perborate monohydrate and tetrahydrate and sodium percarbonate. The peroxy bleach is suitably present in an amount of from 5 to 35% by weight, preferably from 10 to 25% by weight.

The peroxy bleach may be used in conjunction with a bleach activator (bleach precursor) to improve bleaching action at low wash temperatures. The bleach precursor is suitably present in an amount of from 1 to 8% by weight, more preferably from 2 to 5% by weight. Preferred bleach precursors are peroxocarboxylic acid precursors, more particularly peroxoacetic acid precursors and peroxobenzoic acid precursors; and percarbonate precursors. A particularly preferred bleach precursor suitable for use in the present invention is N, N, N ', N' -tetracetylethylenediamine (TAED).

As previously indicated, a bleach stabilizer (heavy metal sequestrant) may also be present. Suitable sequestrants are discussed above.

If desired, the bleaching system may also comprise a transition metal bleach catalyst as described and claimed in EP 458 397A, EP 458 398A and EP 509 787A (Unilever).

Other optional components

The compositions of the present invention may contain an alkali metal carbonate, preferably sodium, to increase detergency and facilitate processing. The sodium carbonate may suitably be present in amounts ranging from 1 to 60% by weight, preferably from 2 to 40% by weight. However, mixtures containing little or no alkali metal carbonate are also within the scope of the invention.

Powder flow may be improved by incorporating a small amount of a powder structurant, for example a fatty acid (or fatty acid soap), a sugar, an acrylate or acrylate / maleate polymer, or sodium silicate.

A preferred powder structurant is a fatty acid soap, preferably in an amount of from 1 to 5% by weight.

Other ingredients that may be present in the detergent composition include sodium silicate; and anti-redeposition agents such as cellulose polymers; other soil release or anti-redeposition polymers; fluorescent substances; inorganic salts such as sodium sulfate; suds control or suds enhancers, as required; detergent enzymes such as proteases, lipases, cellulases and amylases; coloring agents; colored grains; perfumes; foam control agents; and fabric softening agents. This list is not intended to be exhaustive.

Preparation and bulk density

The invention has particular value for compact detergent powders in which the ingredients are in very close proximity, for example to compositions having bulk densities of 650 g / l or more, and in particular of 750 g / l.

High bulk density detergent compositions are generally prepared either by post-tower compaction of the powders prepared by spray drying or by spray-free processes such as mixing and granulation. In both cases, a high speed mixer / granulator may be advantageously used. Processes using a high speed mixer / granulator are described, for example, in EP 340 013A, EP 367 339A, EP 390 251A, EP 420 417A and EP 506 184A (Unilever).

Preferred processes for preparing the compositions of this invention will include the step of mixing and granulating the ingredients in a high speed mixer / thickener to form a high bulk density base powder and optionally post-dosing the ingredients unsuitable for such processing.

The antioxidant can either be included in the high bulk density base powder or be post-dosed. It is desirable that the antioxidant be distributed as homogeneously as possible in the final product.

According to one preferred process, the solution or suspension of the antioxidant in the nonionic surfactant / fatty acid soap mixture is mixed into the base powder prior to dispensing the other solid ingredients.

Alternatively, the antioxidant may be postdosed in particulate form, either alone or in the form of granules, which also contain a carrier material, for example zeolite or sodium carbonate, and optionally a binder, for example sodium silicate or an acrylate or acrylate / maleate polymer.

DETAILED DESCRIPTION OF THE INVENTION

The invention is further illustrated by the following non-limiting Examples in which parts and percentages are by weight unless otherwise indicated.

Examples 1 to 6

Bleaching detergent compositions of high bulk density were prepared with the following general composition:

Coconut alcohol sulphate

Non-ionic PAL 7E0

Non-ionic PAL 3E0

Zeolite MAP

Sodium soap

Sodium carbonate Sodium carboxymethylcellulose BHT

Percarbonate, TAED, etc.

EDTMP Dequest 2047

enzymes

perfume

Foam Control Granules / Fluorescent Water and Salt

5.52

7:50

5.00

34.76

1.95

3.13

0.85 see below

30.07

0.42

1.42

0.45

3.50 to 100.00

PAL - surfactant

The mixtures were prepared as follows. A high bulk density base powder was prepared by mixing and granulating surfactants, zeolite, sodium carbonate, and sodium carboxymethylcellulose in a continuous high speed mixer / thickener (Lodige (trademark) Recycler). Bleaching components, additional sodium carbonate, enzyme granules, and foam / fluorescent substance granules were postdosed subsequently. EDTMP was incorporated into the base of some mixtures and post-dosed into other mixtures.

BHT was introduced in two different ways:

(a) into a base powder (in a high speed mixer / granulator) as a nonionic surfactant / soap / / BHT mixture; or (b) post-dosing in powder form.

The mixtures were prepared as follows:

Example Antioxidant EDTMP

1 0.22% by weight . BHT, postdosed postdosed 2 0.4 % materials. BHT, postdosed postdosed 3 0.1 % materials. BHT, postdosed in the 4 0.2 % materials. BHT, postdosed in the 5 0.3 % materials. BHT, postdosed in the 6 0.4 % materials. BHT, postdosed in the

Example 7

A similar formulation was prepared which contained perborate instead of sodium percarbonate. It contained post-dosed EDTMP and 0.2 wt% BHT post-dosed.

Examples 8 to 10

Non-bleaching detergent compositions with high bulk density

were prepared with the following General composition: Coconut alcohol sulphate 6.35 Non-ionic PAL 7E0 8.63 Non-ionic PAL 3E0 5.75 Sodium soap 2.24 Zeolite MAP 39.99 Sodium carbonate 1.26 Sodium carboxymethylcellulose BHT 0.98 see below Sodium citrate (2H2O) EDTMP Dequest 2047 22.18 1.43 enzymes 1.24 perfume 0.45 Granules for foam control / fluorescent substance 3.20 Water and salts do 100,00

The preparation process was as follows: a high bulk density base powder was prepared as described in Examples 1 to 6; sodium citrate, enzyme granules and foam control / fluorescent granules were postdosed subsequently. EDTMP was post-dosed.

The mixtures were prepared as follows:

Example Antioxidant EDTMP

0.30% by weight. BHT, post-dosed post-dosed

0.1% BHT + 0.1% BHA, post-dosed post-dosed

0.05% BHT + 0.05% BHA, post-dose. postdosed

Claims (16)

PATENT CLAIMS A particulate detergent composition comprising an organic surfactant system comprising anionic and / or nonionic non-soap surfactants, a detergent builder component and other ingredients up to 100% by weight, characterized in that (i) the composition comprises more than 5% by weight primary alcohol sulfate and / or at least 8% by weight of an ethoxylated Cg_20 alcohol nonionic surfactant and / or more than 15% by weight of a total non-soap organic surfactant, (ii) a detergent system comprising an alkali metal aluminosilicate, (iii) the composition further comprising from 0.01 to 5% by weight of an antioxidant, all percentages are based on the total mixture. 2. A detergent composition according to claim 1 wherein the organic surfactant system comprises a primary alcohol sulfate Cg_2Q and a nonionic Cg2Q alcohol surfactant. 3. A detergent composition according to claim 2 wherein the composition comprises more than 5% primary alcohol sulfate by weight. Detergent composition according to claim 2, characterized in that the composition contains more than 15% by weight of a surfactant system (i) comprising a primary alcohol sulphate C 20-20 and a non-ionic C 20-20 ^{and a} 10% surfactant. 5. A detergent composition according to claim 2, wherein the UCA, the combination of the surfactant system comprises (i) containing sulphate ^ 8-20 ^{EXAMPLE vain} and h ° alcohol neió14 new Cg_20 alcohol surfactant in a ratio of currency, j as 1: 1. 6. A detergent composition according to claim 1 wherein the composition comprises at least 10% by weight of an ethoxylated nonionic surfactant. The detergent composition of claim 1, wherein the antioxidant (iii) is a sterically hindered phenol. 8. A detergent composition according to claim 7, wherein the antioxidant (iii) is selected from butylated hydroxytoluene, butylated hydroxyanisole and tert-butylhydroquinone. 9. A detergent composition according to claim 1 comprising from 0.05 to 2% by weight of an antioxidant (iii). 10. The detergent composition of claim 1, further comprising a sequestrant for transition metal ions. The detergent composition of claim 10, wherein the sequestrant comprises aminopolycarboxylates or aminopolyphosphonates. 12. A detergent composition according to claim 10 wherein the sequestrant comprises ethylenediaminetetramethylenephosphonic acid or a salt thereof. 13. A detergent composition as claimed in claim 1 having a bulk density of at least 650 g / l. 14. The detergent composition of claim 1, wherein it is not the product of a spray drying process. A method for preparing a particulate detergent composition according to claim 1, comprising the step of mixing and granulating the ingredients in a high speed mixer / denser to form a high bulk density base powder and optionally post-dosing ingredients unsuitable for processing in the high speed mixer / denser, characterized by by mixing the solution or suspension of the antioxidant in the nonionic surfactant with the base powder prior to post-dosing the other solids. A method for preparing a particulate detergent composition according to claim 1, comprising the step of mixing and granulating the ingredients in a high speed mixer / denser to form a high bulk density base powder and optionally post-dosing components unsuitable for processing in the high speed mixer / denser, characterized by in that the antioxidant is postdosed in particulate form.