WO1998054287A1

WO1998054287A1 - Phosphate-built detergent compositions

Info

Publication number: WO1998054287A1
Application number: PCT/EP1998/002984
Authority: WO
Inventors: William Derek Emery; Terry Instone; Seeng Djiang Liem; Gilbert Martin Verschelling
Original assignee: Unilever Plc; Unilever N.V.
Priority date: 1997-05-30
Filing date: 1998-05-11
Publication date: 1998-12-03
Also published as: CN1137984C; PL337037A1; ZA984215B; CN1261912A; GB9711352D0; EP0985025A1; HUP0002065A2; AR015700A1; EA199901105A1; AU730912B2; BR9809482A; IN190312B; HUP0002065A3; ID27763A; TR199902936T2; AU8209698A

Abstract

Particulate phosphate-built detergent compositions having a surfactant content of at least 15 % by weight, preferably at least 25 % by weight and more preferably at least 30 % by weight, are composed of at least two different granular components: (i) a base powder comprising sodium tripolyphosphate and optionally zeolite, the ratio of sodium tripolyphosphate to any zeolite present being at least 5:1, and (ii) at least 10 % by weight of high-active granules containing at least 60 % by weight of surfactant, and preferably at least 60 % by weight of anionic surfactant. The compositions have excellent flow properties despite the high surfactant content.

Description

PHOSPHATE-BUILT DETERGENT COMPOSITIONS

The present invention relates to particulate phosphate-built laundry detergent compositions of medium to high bulk density having a high content of surfactant, especially anionic surfactant.

Background

High bulk density particulate laundry detergent compositions have been manufactured for a number of years . They have the advantage over low bulk density compositions that they require less volume for storage.

Detergency builder included in detergent compositions may, as is known to the skilled person, be selected from a wide range of materials, of which salts such as sodium carbonate and sodium phosphates and insoluble aluminosilicate compounds such as zeolites are examples.

Sodium phosphates, particularly sodium tripolyphosphate, are found to be effective builders, having particularly good calcium ion binding capacity.

High quantities of organic detergent surfactant (active) are sometimes required in laundry detergent compositions, particularly in compositions intended for washing by hand, to give effective soil removal. However, it has been found that problems of poor powder properties can be encountered in high-active compositions, for example, powder stickiness- leading to agglomeration and poor flow. This is found to be a problem particularly with high bulk density detergent compositions built with large quantities of sodium tripolyphosphate, as this material can have a relatively poor carrying capacity for detergent active, especially in non-spray-dried compositions.

In order to improve the liquid carrying capacity of the detergent composition to allow a high active level, it is known in the art to include a relatively high proportion of material, typically builder material, which has a better carrying capacity than sodium tripolyphosphate. For example, zeolite may be used in this role.

WO 96/38529A (Procter & Gamble) discloses a continuous process for producing high-active high-density detergent granules containing relatively large quantities of phosphate builder, but relatively large quantities of sodium carbonate are also required.

It is an object of the present invention to provide a high bulk density particulate detergent composition having a high surfactant content, having sodium tripolyphosphate as the predominant builder material, the composition having acceptable or good powder properties.

The present inventors have realised that this object can be achieved by formulating the detergent composition with a proportion of the surfactant formulated as particles containing a high proportion of surfactant. Summary of the invention

The present invention accordingly provides a particulate detergent composition comprising at least 15% by weight of organic detergent surfactant, the composition being composed of at least two different granular components:

(i) a base powder comprising sodium tripolyphosphate and optionally zeolite, the ratio of sodium tripolyphosphate to any zeolite present being at least 5:1, and

(ii) at least 10% by weight of granules containing at least 60% by weight of surfactant, and preferably containing at least 60% by weight of anionic surfactant.

It has been found by the inventors that compositions formulated in this way have good powder properties. In particular low stickiness can be achieved, leading to good dynamic flow rate (DFR) .

The detergent compositions of the present invention preferably have a high bulk density, preferably in excess of 600 g/1, particularly preferably in excess of 700 g/1.

The detergent compositions of the present invention are characterised by excellent flow properties. The dynamic flow rate (DFR) , measured as described below, is generally at least 100 ml/s. Preferred compositions of the invention have a DFR of at least 110 ml/s, and more preferably at least 120 ml/s. The compositions of the invention preferably contain from 10 to 90% by weight of the base powder (i) , and from 10 to 60% by weight, more preferably from 15 to 55% by weight, of the high-active granules (ii) .

Organic surfactant

The detergent compositions of the invention will contain one or more detergent active compounds (surfactants) which may be chosen from soap and non-soap anionic, cationic, nonionic, amphoteric and zwitterionic detergent active compounds, and mixtures thereof. Many suitable detergent active compounds 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.

The total amount of surfactant present is at least 15% by weight, preferably at least 25% by weight. Compositions having very high surfactant levels, for example, at least 27% by weight, preferably at least 28% by weight, more preferably at least 30% by weight and even at least 35% by weight, are of especial interest because it has not previously been found possible to prepare medium or high bulk density flowable phosphat-built powders containing such high surfactant loadings .

Anionic surfactant

Preferred compositions of the invention contain non-soap anionic surfactant, and may optionally also contain other surfactant types, notably, soaps and/or nonionic surfactants .

Anionic surfactants are well known to those skilled in the art. Examples include alkylbenzene sulphonates, particularly linear alkylbenzene sulphonates having an alkyl chain length of C₈-Cι₅; primary and secondary alkylsulphates, particularly C₈-Cι₅ primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl sulphosuccinates ; and fatty acid estersulphonates. Sodium salts are generally preferred. Preferably, there is less than 10% by weight of primary alcohol sulphate, more preferably 5% by weight or less.

Preferably, the quantity of anionic surfactant is in the range of 15 to 60 % by weight of the total composition. Preferably it is at least 25%, more preferably at least 30% by weight, and may be as high as at least 35% by weight. The preferred region is from 25 to 45% by weight.

The anionic surfactant may be solely within the granules (ii) , but is more preferably present also in the base powder (i) •

Optional nonionic surfactant

Nonionic surfactants may optionally be present in the compositions of the invention, suitably in amounts within the range of from 5 to 20% of the composition.

Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the C₈-C₂₀ aliphatic alcohols ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the C₁₀-C₁₅ primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkylpolyglycosides , glycerol monoethers, and polyhydroxyamides (glucamide) .

The high-active granules (ii)

More than one type of high-active granules (ii) may be present, provided that in total at least 10% by weight of the composition is constituted by these granules.

It is particularly preferred that the high-active granules (ii) containing at least 60% by weight of surfactant comprise a substantial quantity of anionic surfactant. Preferably, the granules comprise at least 60% by weight of anionic surfactant, more preferably at least 70% by weight of anionic surfactant.

A method of producing a detergent component containing at least 60% by weight of anionic surfactant is set forth in WO 97/32002A (Unilever) . The process comprises the steps of feeding a paste material comprising water and an anionic surfactant into a drying zone, heating the paste material in the drying zone to reduce the water content thereof and subsequently cooling the paste material in a cooling zone to form detergent particles, characterised by introducing a layering agent into the cooling zone during the cooling step. This process may be carried out in a machine manufactured by VRV Impianti SpA, having a heating surface area of 1.2 m². The heating zones are maintained at a temperature in the region of 120-190°C, for example 170°C. Cooling is achieved using ambient process water at 15°C. The apparatus is used with tip speed of the blades of 30 m/s.

A method of producing a detergent component containing at least 75% by weight of anionic surfactant is set forth in WO 96/06916A and WO 96/06917A (Unilever) . In the process of the former application, a paste material comprising water in an amount of more than 10% by weight of the paste and the surfactant is fed into a drying zone, the paste is heated to a temperature in excess of 130°C to reduce the water content to more than 10% by weight and the material is subsequently cooled to form detergent particles.

High-active granules (ii) containing anionic surfactant may be present at a level of from 5 to 45% by weight, preferably from 5 to 40% by weight. If these are the only granules present in which the surfactant level is at least 60% by weight, then they must be present in an amount of at least 10% by weight.

Preferably, a major proportion of the anionic surfactant is contained in the high-active granules (ii) containing at least 60% by weight of anionic surfactant. The remainder of the anionic surfactant may be present in any other suitable form. Preferably, the remainder of the anionic surfactant will be present in the base powder. Preferably, at least 45% by weight of the anionic surfactant is incorporated in the high-active granules. Nonionic surfactant may also be present in the form of high- active granules, although these need not necessarily contain at least 60% by weight of nonionic surfactant. A method of manufacturing nonionic surfactant containing granules comprising 55% by weight or more of nonionic surfactant, at least 5% by weight of silica of oil absorption capacity of 1.0 ml/g and less than 10% by weight of aluminosilicate are disclosed in our copending application of even date (reference C3777) entitled "Detergent Compositions Containing Nonionic Surfactant Granule"

These granules can be manufactured by mixing together components in a high speed granulator (for example an Eirich RV02 Granulator) . Alternatively, 70 to 100% by weight of the solid components and 70 to 95% by weight of the nonionic surfactant can be mixed together in a first step, the remainder of the solid components and nonionic surfactant being added in a second step, preferably under moderate shear. In the second process, the majority of the structurant is preferably added in the second step.

The base powder (i)

The base powder may be manufactured by spray-drying or agglomeration techniques, as are well known in the art. The base powder may be prepared by spray-drying followed by densification or by a wholly non-tower method. Preferably, the base powder is manufactured by spray-drying followed by densification, or by non-tower granulation. Preferably, the base powder has a bulk density in excess of 600 g/1. The invention is also applicable to spray-dried base powders of lower bulk density that have not subsequently been densified, but it is of especial interest in the context of high-bulk-density base powder of low porosity. The densification step or granulation process is preferably carried out in a high speed mixer/granulator . Processes using high-speed mixer/granulators are disclosed, for example, in EP-A-0340013 , EP-A-036733 , EP-A-0390251 and EP- A-0420317 (Unilever) .

The base powder may contain surfactant. It preferably comprises at least 5% by weight of anionic surfactant, preferably in the region of 10 to 30% by weight. The base powder also contains builder, which comprises sodium tripolyphosphate and which may also comprise other builders, notably zeolite. The content of builder in the base powder is preferably above 50% by weight, more preferably at least 70% by weight, of the base powder.

Nonionic surfactant may be present in the base powder or, as previously indicated, as high-active granules, such granules preferably containing at least 60% by weight of nonionic surfactant .

Nonionic surfactant may be additionally or alternatively present in the base powder as discussed above. If present in the base powder, the nonionic surfactant preferably comprises from 5 to 30% by weight, more preferably from 10 to 20% by weight, of the base powder. Detergency builder

The granular detergent compositions of the present invention comprise builder material, preferably at a level of from 10 to 60% by weight, more preferably from 30 to 50% by weight. As an essential builder ingredient the composition comprises sodium tripolyphosphate, preferably within the range of from 20 to 50% by weight. Preferably at least 60% of the builder is in the base powder.

The detergent composition of the invention may also contain a crystalline aluminosilicate, preferably an alkali metal aluminosilicate, more preferably a sodium aluminosilicate. If zeolite is present, the ratio of sodium tripolyphosphate to zeolite in the base powder is at least 5:1, preferably at least 7:1, but there may be no aluminosilicate at all.

Sodium tripolyphosphate of high hydration level can be used. In normal practice, it is common to use sodium tripolyphosphate of low hydration level, in order to increase its carrying capacity. However, using low hydration sodium tripolyphosphate has the disadvantage that the tendency to the material to cake on storage is increased. By pre-hydrating the sodium tripolyphosphate, caking can be further reduced.

Aluminosilicate may generally be incorporated in amounts of from 5 to 18% by weight (anhydrous basis), preferably from 10 to 15 wt %. Aluminosilicates are materials having the general formula:

0.8-1.5 M₂0. A1₂0₃. 0.8-6 Si0₂ where M is a monovalent cation, preferably sodium.

The zeolite optionally used in the compositions of the present invention may be the commercially available zeolite A (zeolite 4A) now widely used in laundry detergent powders. However, according to a preferred embodiment of the invention, any zeolite incorporated in the compositions of the invention is maximum aluminium zeolite P (zeolite MAP) as described and claimed in EP 384 07OB (Unilever) , and commercially available as Doucil (Trade Mark) A24 from Crosfield Chemicals Ltd, UK.

The detergent composition may contain amorphous or crystalline water-soluble alkali metal silicate, preferably sodium silicate having a Si0₂:Na0 mole ratio within the range of from 1.6:1 to 4:1, preferably 2:1 to 3.3:1.

The water-soluble silicate maybe present in an amount of from 1 to 20 wt %, preferably 3 to 15 wt % and more preferably 5 to 10 wt %, based on the aluminosilicate (anhydrous basis) .

As well as the sodium tripolyphosphate and crystalline aluminosilicate builders already mentioned, other inorganic or organic builders may be present. Inorganic builders that may be present include sodium carbonate, layered silicates (eg SKS-6 from Hoechst) , amorphous aluminosilicates, and other phosphate builders, for example, sodium orthophosphate or pyrophosphate.

Organic builders that may additionally be present include polycarboxylate polymers such as polyacrylates and acrylic/maleic copolymers; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-di-- and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates , dipicolinates , hydroxyethyliminodiacetates, alkyl- and alkyenylmalonates and succinates; and sulphonated fatty acid salts.

Especially preferred organic builders are citrates, suitably used in amounts of from 5 to 30 wt %, preferably from 10 to 25 wt %; and acrylic polymers, more especially acrylic/maleic copolymers, suitably used in amounts of from 0.5 to 15 wt %, preferably from 1 to 10 wt % .

Builders, both inorganic and organic, are preferably present in alkali metal salt, especially sodium salt, form.

The builder components may be present in the form of a builder granule which consists substantially only of builder components. However, it is preferable that the builder is present in the base powder as discussed above, with surfactant. Preferably, builder comprises in the region of from 10 to 70% by weight of such a base powder, more preferably in the region of from 15 to 50% by weight.

Preparation of the detergent composition

The composition of the invention is suitably prepared as follows: the base powder is manufactured and dry-mixed with the granules (ii) containing at least 60% by weight of surfactant. Other ingredients

The composition of the present invention may constitute a detergent composition in its own right. Preferably, however, further components are post-dosed to provide improved washing qualities and benefits .

Detergent compositions according to the invention may also suitably contain a bleach system. The compositions of the invention may contain peroxy bleach compounds capable of yielding hydrogen peroxide in aqueous solution, for example inorganic or organic peroxyacids, and inorganic persalts such as the alkali metal perborates, percarbonates, perphosphates, persilicates and persulphates .

The sodium percarbonate may have a protective coating against destabilisation by moisture. Sodium percarbonate having a protective coating comprising sodium metaborate and sodium silicate is disclosed in GB 2 123 044 (Kao) .

The peroxy bleach compound, for example sodium percarbonate, is suitably present in an amount of from 5 to 35 wt %, preferably from 10 to 25 wt %.

The peroxy bleach compound, for example sodium percarbonate, 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 wt %, preferably from 2 to 5 wt % .

Preferred bleach precursors are peroxycarboxylic acid precursors, more especially peracetic acid precursors and peroxybenzoic acid precursors; and peroxycarbonic acid precursors. An especially preferred bleach precursor suitable for use in the present invention is N, N, N' , N'- tetracetyl ethylenediamine (TAED) .

A bleach stabiliser (heavy metal sequestrant) may also be present. Suitable bleach stabilisers include ethylenediamine tetraacetate (EDTA) , ethylenediamine disuccinate (EDDS) , and the aminopolyphosphonates such as ethylenediamine tetramethylene phosphonate (EDTMP) and diethylenetriamine pentamethylene phosphonate (DETPMP) .

The compositions of the present invention may also include a bleach catalyst, such as manganese cyclononane derivative.

The compositions of the present invention may also contain soil release polymers, for example sulphonated and unsulphonated PET/POET polymers, both end-capped and non- end-capped, and polyethylene glycol/polyvinyl alcohol graft copolymers such as Sokalan (Trade Mark) HP22.

The compositions of the invention may also contain dye transfer inhibiting polymers, for example, polyvinyl pyrrolidone (PVP) , vinyl pyrrolidone copolymers such as PVP/PVI, polyamine-N-oxides, PVP-NO etc.

A powder structurant, for example, a fatty acid (or fatty acid soap) , a sugar, an acrylate or acrylate/maleate polymer may be included in the granular components . A preferred powder structurant is fatty acid soap, suitably present in an amount of from 1 to 5 wt % .

It is particularly preferred to include sodium carbonate. This has the advantage that it helps to structure the granule, can act to control the pH of the detergent composition when dissolved and acts as a builder. Preferably 5 to 30% by weight sodium carbonate may be present. Minor ingredients such as layering agents (for example zeolite, Alusil (trade mark) or clay) may be present, for example, at a level of 0.1 to 10%.

Other materials that may be present in detergent compositions of the invention include antiredeposition agents such as cellulosic polymers; fluorescers ; photobleaches ; inorganic salts such as sodium sulphate; foam control agents or foam boosters as appropriate; enzymes (proteases, lipases, amylases, cellulases) ; dyes; coloured speckles; perfumes; and fabric conditioning compounds.

Ingredients which are normally but not exclusively postdosed, may include bleach ingredients, bleach precursor, bleach catalyst, bleach stabiliser, photobleaches, alkali metal carbonate, water-soluble crystalline or amorphous alkaline metal silicate, layered silicates, anti-redeposition agents, soil release polymers, dye transfer inhibitors, fluorescers, inorganic salts, foam control agents, foam boosters, proteolytic, lipolytic, amylitic and cellulytic enzymes, dyes, speckles, perfume, fabric conditioning compounds and mixtures thereof .

The present invention will be further illustrated by means of the following non-limiting Examples.

Except where stated otherwise, all quantities are parts or percentages by weight . EXAMPLES

Measurement of dynamic flow rate (DFR)

Dynamic flow rate (DFR) is measured by the following method.

The apparatus used consists of a cylindrical glass tube having an internal diameter of 35 mm and a length of 600 mm. The tube is securely champed in a position such that its longitudinal axis is vertical. Its lower end is terminated by means of a smooth cone of polyvinyl chloride having an internal angle of 15° and a lower outlet orifice of diameter 22.5 mm. A first beam sensor is positioned 150 mm above the outlet, and a second beam sensor is positioned 250 mm above the first sensor.

To determine the dynamic flow-rate of a powder sample, the outlet orifice is temporarily closed, for example, by covering with a piece of card, and powder is poured through a funnel into the top of the cylinder until the powder level is about 10 cm higher than the upper sensor; a spacer between the funnel and the tube ensures that filling is uniform. The outlet is then opened and the time t (seconds) taken for the powder level to fall from the upper sensor to the lower sensor is measured electronically. The measurement is normally repeated two or three times and an average value taken. If V is the volume (ml) of the tube between the upper and lower sensors, the dynamic flow rate DFR (ml/s) is given by the following equation:

DFR=V/t The averaging and calculation are carried out electronically and a direct read-out of the DFR value obtained.

EXAMPLES 1 TO 6

Six particulate detergent compositions as shown in the table below were manufactured as follows.

Base powders comprising the components listed in the first 8 lines was prepared by dosing the components into a high- speed Fukae batch granulator and granulating. The sodium LAS in the base powder (where present) was prepared by in situ neutralisation of LAS acid with sodium carbonate. The materials were granulated until powder with good particle size was obtained. If necessary, the powder was layered with zeolite.

The LAS granules Al were prepared in a flash dryer by dry neutralisation of LAS acid with sodium carbonate. A 1.2 m² VRV flash-drier machine was used having three equal jacket sections. Dosing ports for liquids and powders were situated just prior to the first hot section, with mid- jacket dosing ports available in the final two sections. Zeolite was added via this port in the final section. An electrically-powered oil heater provided the heating to the first two jacket sections. Ambient process water at 15°C was used for cooling the jacket in the final section. Make-up air flow through the reactor was controlled between 10 and 50 m³/kg hr by opening a bypass on the exhaust vapour extraction fan. All experiments were carried out with the motor at full-speed giving a tip speed of about 30 m/s. Screw-feeders were calibrated to dose sodium carbonate and zeolite MAP for layering. The sodium carbonate and liquids were added just prior to the first hot section and zeolite layering was added into the third section which was cold. The minimum level of zeolite was added to give free- flowing granules leaving the drier.

A jacket temperature of 145°C was used in the first two sections, with an estimated throughput of components 60 to 100 kg/hr. A degree of neutralisation of alkyl benzene sulphonate of greater than 95% was achieved.

This resulted in granules with the following composition.

The LAS granules Al were dry-mixed in a low shear mixer with the base powders produced in the Fukae granulator to provide detergent compositions having the bulk densities indicated.

Good DFR values were obtained, indicating low stickiness in the products. As can be seen below, compositions having very high active - (total surfactant) levels, about 35%, and very high quantities of sodium tripolyphosphate, can be prepared as free-flowing powders. These compositions have good flow rates in spite of the presence of little or no zeolite.

According to the invention, large quantities of zeolite are not required to carry the large quantities of surfactant.

Detergent compositions: Examples 1 to 6

Trade Mark: acrylic/maleic copolymer ex BASF ² Alkyl ether sulphate: Empicol 0251-70 ex Albright & Wilson, supplied as 70% paste EXAMPLES 7 to 12

In Examples 7 to 12 , granules containing high concentrations of anionic surfactants - LAS, primary alcohol sulphate (PAS) and alpha-olefin sulphonate (AOS) - are admixed with phosphate-built base powders containing moderate levels of LAS and/or nonionic surfactant.

LAS granules A2 were made as described for Examples 1 to 6 , using a 2m² VRV machine. In this case the granules contained 70% wt% NaLAS, 20 wt% zeolite 4A and 5 wt% zeolite MAP.

PAS granules A3 were produced by drying a primary alcohol sulphate (PAS) paste containing 70% neutralised cocoPAS and 30% water in a dryer/granulator supplied by VRV SpA, Italy, as follows. The temperature of the material fed into the drying zone was set at 60°C and a small negative pressure was applied to the drying zone. A throughput in the flash drier of 120 kg/hr of paste was used. The temperature of the wall of the drying zone was initially 140°C. The heat transfer area of the drying and cooling zones was 10 m² and 5m² respectively. The temperature of the wall of the drying zone was raised in steps to 170°C. Correspondingly, the throughput was increased in steps to 430 kg/hr at 170°C. The particles then passed to a cooling zone operated at a temperature of 30°C.

AOS granules A4 were produced in a similar manner by drying an AOS paste containing 70% neutralised AOS and 30% water in a dryer/granulator supplied by VRV SpA, Italy. The temperature of the material fed into the drying zone was set at 60°C and a small negative pressure was applied to the drying zone. The temperature of the wall of the drying zone was initially 140°C. The heat transfer areas of the drying and cooling zones were 0.8 m² and 0.4 m² respectively. The temperature of the wall of the drying zone was raised in steps to 155°C. The particles then passed to a cooling zone operated at a temperature of 30°C and were collected as free flowing granules .

The high-active granules had the following compositions:

Detergent base powders were produced by using a Lδdige CB30 mixer, in which the various ingredients were mixed together, followed by a densification step in a Lδdige KM300 mixer. The resulting powders were cooled in a fluid bed. In the CB30 mixer, phosphate and sodium carbonate were dosed as solid components .

In case of base powder Fl, LAS acid was dosed and neutralised with the sodium carbonate to make NaLAS. At the same time a mixture of nonionic (Synperonic A7 and Synperonic A3 ex ICI) and fatty acid (Pristerene 4916 ex - Unichema) were dosed, as well as a 40% Sokolan CP5 solution.

In case of base powder F2 , no LAS acid was dosed. The CB30 was operated at 1500 rpm and the exiting powder was layered with zeolite MAP prior to entering the KM300. After cooling in the fluid bed, powders were collected with the following compositions :

These detergent powders were mixed with the above described LAS, PAS and AOS granules, as well as other post dose materials to produce fully formulated detergent powders as shown below.

As can be seen high active (total surfactant) levels can be achieved, whilst maintaining good flow properties. Examples 7 to 12 : detergent compositions

Examples 13 to 17

Base powders F3 , F4 and F5 were prepared as described in Examples 1 to 6 , using a Fukae batch granulator. These were mixed with the anionic granules A3 and A4 described in Examples 7 to 12 to give full formulations within the invention.

Examples 18 and 19

These Examples illustrate formulations containing a nonionic granule as well an anionic granule and a base powder. In Example 18 the base powder was a non-tower base containing surfactant, while in Example 19 the base powder was a builder-only granule.

Base powder F8 was prepared by using a Lδdige CB30 mixer, in which the various ingredients were mixed together, followed by a densification step in a Lδdige KM300 mixer. The resulting powders were cooled in a fluid bed. In the CB30 mixer, phosphate and sodium carbonate were dosed as solid components. LAS acid was dosed and neutralised with the sodium carbonate to make NaLAS. At the same time a 40% Sokalan CP5 solution was dosed. The CB30 was operated at 1500 rpm and the exiting powder was layered with zeolite MAP prior to entering the KM300. After cooling in the fluid bed, powder was collected with the following composition:

Base powder (builder granule) F9 was prepared by continuously dosing STP in a Schugi Flexomix, while spray- drying on a 10% alkaline silicate solution. The resulting powder was cooled in a fluid bed and collected. The following powder was obtained:

A nonionic granule Nl was also prepared. The process route consisted of a Lodige CB30, followed by a Niro fluid bed and a Mogensen sieve. The Lodige CB30 was operated at 1500 rpm.

Water was used to cool the CB30 jacket during the process.

The air flow in the Niro fluid bed was 900-1000 m³/hr. The total flow of powder exiting the process was in the order of 600 kg/h.

Silica (Sorbosil (Trade Mark) TC15) was continuously dosed into the CB30, into which also a mixture of nonionic surfactant (Lutensol A07 ex BASF) and fatty acid (Pristerene 4916 ex Unichema) was dosed via dosing pipes. At the same time 50% NaOH was dosed to neutralise the fatty acid. This set of solid and liquid materials was mixed and granulated in the CB30 after which the resulting powder was entered in the fluid bed and cooled with ambient air. Fines were filtered from the air stream with a cyclone and filter bags. Coarse particles (>1400μm) were separated from the product by the Mogensen sieve.

Anionic granule A2 was prepared as described earlier in Examples 1 to 6 and had the following composition:

With these ingredients the following powders having high surfactant contents and excellent flow rates were assembled:

Claims

1 A particulate detergent composition comprising at least 15% by weight of organic detergent surfactant, characterised in that it is composed of at least two different granular components :

(ii) at least 10% by weight of granules containing at least 60% by weight of surfactant.

2 A detergent composition as claimed in claim 1, characterised in that it has a bulk density of least 600 g/1.

3 A detergent composition as claimed in any preceding claim, characterised in that it contains at least 25% by weight of total surfactant.

4 A detergent composition as claimed in claim 3 , characterised in that it contains at least 28% by weight of total surfactant. 5 A detergent composition as claimed in claim 4, characterised in that it contains at least 30% by weight of total surfactant.

6 A detergent composition as claimed in any preceding claim, characterised in that the granules (ii) contain at least 60% by weight of anionic surfactant.

7 A detergent composition as claimed in any preceding claim, characterised in that the base powder (i) contains at least 5% by weight of anionic surfactant.

8 A detergent composition as claimed in any preceding claim, characterised in tht the base powder has a bulk density of at least 600 g/litre and is prepared by spray- drying and densification, or by non-tower granulation.

9 A detergent composition as claimed in any preceding claim, characterised in that it contains from 10 to 90% by weight of the base powder (i) .

10 A detergent composition as claimed in any preceding claim, characterised in that it comprises from 10 to 60% by weight of the granules (ii) . 11 A detergent composition as claimed in any preceding - claim, characterised by a dynamic flow rate of at least 100 ml/s .

12 A detergent composition as claimed in claim 11, characterised by a dynamic flow rate of at least 110 ml/s