MXPA97002347A - Compositions highly active granular detergents and processing for elaboration - Google Patents

Abstract

The present invention relates to a process for making a detergent composition having at least 40% by weight with a surfactant and a bulk density of at least 650 g / l, the process comprising the single step of mixing with high shear until granulated to a temperature on the scale from ambient temperature to 60 ° C, a binder component comprising the surfactant and less than 20% water, with a solid component in particles of initial particle size from 0.1 to 500 microns, the particulate solid component has less 15% by weight of particles with a particle size of at least 50 microns and a sufficient quantity of smaller particles so that the average surface area of the particulate component is at least 9 m / g as measured by the BET method and where the binder keeps the mixture in the particulate state through the entire procedure

Description

COMPOSITIONS HIGHLY ACTIVE GRANULAR DETERGENTS AND PROCEDURE FOR ELABORATING THEM D E S C R I P C I O N This is a request that is a continuation in part of the pending application S / N 08/083115, filed on June 25, 1993, which is a continuation in part of the application S / N 07/980856, filed on October 24, 1993. November 1992 and now abandoned, which is a continuation in part of the pending application S / N 07/816408, filed on December 31, 1991 and now abandoned.

Technical Field - The present invention relates to a process for making a highly active granular detergent composition and in particular a granular detergent composition with a high bulk density, ie having a bulk density greater than 600 g per liter and at least 40% by weight of surfactants. Preferably, the granular detergent composition has good powder properties. More particularly, the invention relates to a process for the preparation of a granular detergent composition, especially one with a high proportion of surfactant.

Background and Previous Technique. - Granular detergent compositions with high levels of surfactant of about 40% by weight or higher have several advantages over compositions with lower concentrations, particularly in work environments that use low amounts of water. In addition, granular detergent compositions of high bulk density have several advantages over compositions of low bulk density. The volume of packaging of the granules is lower, which means that the packaging can be smaller which facilitates the storage and transportation of the products. The factors that govern the volumetric density of detergent granules are the volumetric density of the starting materials, for those granules produced by dry mixing and the chemical composition of the slurry for those granules produced by spray drying. Given the restrictions to formulate effective compositions that are made using either one of these factors to vary the volumetric density, the substantial increase in volumetric density can only be achieved to a greater degree by mechanical processing.

In view of the increased environmental requirements, it is desirable to reduce the water consumption thereby saving water as well as the energy used to heat it. According to the above, very active powders suitable for use with washings with little water are highly beneficial.

Mainly, commercial high volumetric density granules are produced by mechanical densification of a powder that: = e dries by spray. This route for high volume density detergent granules is an intensive route of energy and capital. The equipment used to produce spray drying is expensive and the procedure itself removes 30-40% by weight of water from the slurry that is energy intensive. As spray drying is a hot process it also places restrictions on what can be included in the formulation, in particular nonionic surfactants which can give rise to undesirable emissions and sensitive or volatile components such as enzymes and perfumes that can degrade or to lose. After spray drying, additional equipment and energy are needed for additional mechanical processing to densify the powder.

EP-A-337330 (HENKEL) refers to a continuous process for obtaining a detergent powder of high volumetric density containing a considerable amount of anionic and nonionic surfactant, this process comprises treating spray-dried detergent material in a high speed mixer with the addition of non-ionic material, whereby the average residence time in the mixer is from 10 to 60 seconds.

In the patent US-no. 4 '923, 636 and US-4 '826, 632 of Blackburn et al. and US Pat. No. 5,324,445 to Dumas et al. liquid surfactant compositions that can be sprayed on spray dried powders have been disclosed to increase the bulk density. While these "densified" spray-dried powders have not been produced by mechanical densification, the disadvantages of using a spray-dried powder as a starting point remain. Furthermore, only a limited level of liquid surfactant can be sprayed if the powder properties are not altered and the spray process rests on an absorbent powder base.

There are many drying processes that do not use aspersion in the prior art and that produce detergent granules. These have drawbacks too. Most, in a first stage, form a mass that is deagglomerated in a second stage to form granules. Usually, then the granules are coated and dried in additional stages. An example of such a procedure is described in US Patent no. 5 '045, 238, Jolicoeur. This multi-stage process requires more than one mixer and a separate granulation operation. Other procedures require the use of the acid form of the surfactant to work. Some others require high temperatures that degrade the starting materials.

In the US patent no. 4 '925,589 Strauss et al., Issued May 16, 1990, it is disclosed that certain detergent compositions with high bulk density can be made by a fine dispersion process, by mixing a surfactant paste and a detergent to form a sticky mass as an intermediate material. To form granules of this mass it is necessary to cool it, for example, with dry ice at temperatures as low as minus 25 ° C followed by additional mixing to form large granules. To achieve the desired moisture content the granules are dried in a separate drying step, for example, in a fluid bed dryer. This process comprises at least 3 stages, it is long and expensive because of the cooling and drying requirements. In the US patent no. 4 * 666,740 of Wixxon issued May 19, 1987, it is disclosed that certain high volume density detergent particles can be made by a process of spraying a liquid or nonionic detergent pasty on preformed carbonate-bicarbonate beads. The beads are then coated with zeolite to form free-flowing particles.

The European patent application no. 420,327 to Appel discloses a 3 step process for preparing a granular detergent composition of high bulk density by in situ neutralization of a liquid acid precursor of an anionic surfactant. Typically, in this type of process, an excess of carbonate is required to ensure a reasonable conversion of the acid. Excess carbonate results in an undesirably high pH in the product. The use of the acid precursor also requires handling, storage and coordination with careful granulation.

Beerse et al., US Pat. No. 5,108,646, describes a granulation process for making a granular detergent former, rather than a complete detergent composition. Critically, the invention of the applicants requires at least about 40% by weight of active surfactant and further describes a granulation route for making a complete detergent. Applicant particles contain detergent solids such as formers and fillers and active mixed surfactant with a very low water content as the binder for the granulation process. B erse et al. discloses a granulation process using an aqueous mixed active paste, although the granules must be combined with at least 1.3 times their weight of spray-dried base granules to produce a complete detergent product. The solid forming portion of Beerse et al. it must be selected from zeolites or silicates and the size of the solids is restricted to 0.1 to 10 microns. The present invention allows any solid ingredient of the detergent to include anhydrous sodium carbonate or sodium sulfate and on a much larger scale scale. Also, the relationship of Beerse et al. of anionic to non-ionic surfactant is limited to 3: 1 or greater, unlike the present invention. In the Beerse annexation particle, the weight ratio of trainer to binder is 1.75: 1 to 3.5: 1. The maximum amount of surfactant in the annexation is thus about 36%. There is a need for a process for making a granular detergent composition especially of high bulk density, which does not use a spray-dried powder as a starting material and which mitigates the disadvantages and complexities of the processes of the prior art.

We have found that it is possible to make a granular detergent composition of highly active volumetric density in a simple low energy process, using readily available starting materials. We have found that it is possible to make a highly active granular detergent composition by a low energy green process preferably with a high surfactant content.

In particular, we have found that these and other preferred objects can be achieved by adding a mobile surfactant system comprising anionic surfactants and a non-ionic alkoxylated surfactant to particulate starting materials during the treatment of this starting material in a mixer. high speed densifier. The anionic surfactants can be linear alkylbenzene sulphonate, alkyl sulfate and the like. It has been found that an upper detergent powder containing high levels of surfactant produced with solid detergent granulation ingredients can be produced with a binder composed of a liquid mixture with a low moisture content of anionic and nonionic surfactants and small particulate components with high surface areas that act as granulation aids. The complete particulate mixture can have a high surface area or the elevated surface area can be achieved by manipulating selected components of the mixture. The levels of active (surfactant) that can be reached are as high as 60% by weight of surfactants and at least 40% by weight. The advantages are the increased level of active that can be incorporated into the granulate by comparing the granulations without the high surface area components.

THE INVENTION According to the foregoing, the invention provides a process and a product prepared by the process for making a detergent composition of high active density, which comprises the steps of: mixing with high shear until granulated with a binder component, comprising a neutralized or partially neutralized surfactant with a particulate solid component, of an initial particle size of about 0.1 to 500 microns, wherein the binder maintains the mixture in a particulate state throughout the process. The particle size of at least 15% by weight of the particulate solids should be at least 50 microns and preferably about 50 to 400 microns to provide seed. It has been found that if a particle having an appropriate particle size and surface area is added in a sufficient amount such that the total particle employed has an average surface area above at least 9 m 2 / g and preferably over Up to at least 15 m2 / g measured by the BET method, then particularly high amounts of active can be used, theoretically, as much as 60%.

The advantages of this procedure and product are that it is simple because only one mixer and one stage are necessary, the operating costs are low and the procedure can be worked at room temperature. According to the above, there is less ecological damage in relation to energy requirements. There is no need for a drying step for most formulations. The process is flexible because sensory components can be included with the solid and binder components and at the beginning of the process the need for a subsequent dosing is eliminated.

The process is essentially an agglomeration process, wherein the solid component is agglomerated by the binder component, which results in detergent particles containing the solid component of a surfactant phase. The use of sufficient high surface area solids allows the adsorption of more liquid surfactant per weight of solid.

The advantage of this agglomeration process over a process in which a mobile surfactant composition is absorbed into a particulate starting material is the fact that by agglomeration, much higher levels of mobile surfactant material can be incorporated into the composition at the same time that good powder properties are maintained.

This agglomeration process can be carried out either as a continuous process or a batch process. However, a continuous process is preferred.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for making a highly active, high volumetric detergent composition as well as the composition itself, the method comprising the steps of: (i) introducing a binder component comprising a neutralized or partially neutralized surfactant and a solid component of initial particle size of submicras up to about 500 microns in a mixer of high cross section to thereby form a particulate mixture; and (ii) subjecting the mixture to high cross section mixing and thereby granulating the components to form granules of a size within the range of 1 to 1200 microns. Preferably, after this mixing, a coating agent such as zeolite is added to the mixer.

The detergent composition is suitably a complete detergent composition. The term "complete" is used as a reference to a detergent composition comprising sufficient surfactant, former and an alkaline source to function as an effective powder for washing fabrics. The alkaline source refers to anhydrous sodium carbonate or phosphates.

The term "complete" does not restrict the addition of certain minor components in conventional amounts, for example to weights less than 5%. These minor components include enzymes, bleaches, perfumes, anti-deposition agents or dyes, to improve the performance of the washing powder.

If desired, the particulate detergent composition can be used as a feedstock in a detergent production process. For example, a liquid component surfactant such as a nonionic surfactant can be sprayed onto the composition and then coated with, for example, zeolite. If the detergent composition is used as a feedstock, it is preferred that it be the direct product of the process of the present invention. That is, no additional components are incorporated into the detergent particles before use as a feedstock. However, if desired, the particles can be mixed with separate particles comprising other materials. This provides the advantage of allowing the production of the detergent composition in one place by a single-stage process and optionally mixing with separate particles and then transported to a remote location for storage or further processing, if desired.

For use as a feed material, the detergent composition is in a practically pure form. By "practically pure form" it should be understood that the composition may contain up to 10% by weight of other particulate materials but is practically pure in relation to other materials.

The particle to solid component can have at least 15% solids with a particle size of 50 microns and the average surface area of the solid should be at least of and m / g.

An important feature of the present invention is that the mixture remains in particulate or granular form throughout the entire process. If a mass is not formed, this means that no non-deagglomeration stage is required. For this reason, the procedure is simple and the final product can be elaborated in a single stage.

In the context of the present invention, "particle size or dimension" shall be understood to mean the average particle dimension determined by Rosin-Rammler calculation.

It is important that the process is well controlled, a robust process results in a detergent powder with a desired particle size scale and powder properties that are comparable to those of the detergent powders normally on the market. In order to obtain detergent powder with good powder properties, it is advantageous to add, in addition to the binder, one or more components with a composition such that an increase in the significant viscosity of the resulting total binder is obtained. The addition of these components gives rise to the viscosity mentioned above, in general by at least a factor of 5, preferably by at least a factor of 10, an increase in viscosity of at least a factor of 100 is what is most preferred (when measured in a Haake viscometer at a shear rate of between 0.1 and 20 S.

As a result of the increase in viscosity, the process appears much more easily controlled which results in better powder properties for the detergent composition.

Examples of components that give rise to this viscosity are water and in particular, fatty acid in combination with a stoichiometric amount of alkaline material (such as caustic soda (sufficient to neutralize the fatty acid with obvious results in the formation of soap).

In the process, a solid component which may comprise detergency builders such as water-soluble inorganic alkaline materials (for example sodium carbonate seeded with calcium carbonate), zeolite, sodium tripolyphosphate, other water-soluble inorganic materials, example, sodium silicate or bicarbonate, fluorescent, polycarboxylate polymers, anti-redeposition agents and fillers, is mixed with a binder component which, in addition to a neutralized or partially neutralized surfactant, may contain water, a silicate solution, components of liquid polymers, polyethylene glycols, perfumes, fatty acids and other materials. In the context of the present invention, the term "binder" includes any component that is plastically deformable under the conditions found during the process.

This invention allows higher levels of surfactant to be incorporated into detergent powders produced by granulation. Unexpectedly, the division of a small fraction by weight of particles having sufficient high surface area so that the average surface area of the particulate solids is at least about 9 m 2 / g and preferably at least approximately 15 m2 / g greatly improves the amount of surfactant that can be added. At least 15% by weight of the particulate solids should have a particle size of at least 50 microns, preferably 50 microns to 400 microns to provide a site as a seed. Further, preferably the high surface area solids have an average diameter that differs from the other common solid components. This leads to a marked increase in the weight ratio of surfactant to solids. Specifically, the inclusion of additional high surface area particulate components, which results in a total surface area of solids exceeding 9 μg, preferably at least 12 m 2 / g and even more preferably at least 15 m2 / g. g, it extends the weight levels of surfactant achievable to 60% by weight.

You can reach high surface areas by using porous particles, such as zeolite MAP, Sipernat or using very small particles (submicrons), such as Cabot Cab-O-Sil. Other porous particles are also suitable. The high surface area of the resulting mixture of particles then allows more liquid active to be adsorbed by weight of solid. In addition, the multimodal distribution of particles resulting from the mixing of different components imparts greater resistance to the granulate. The small particles in the distribution serve to increase the yielding effort and viscosity of the binder mixture of liquid asset, which promotes the efficient agglomeration of the components into larger particles. The multimodal distribution of particles also results in a more efficient packing of the solids which reinforces the granulate. Although a more efficient packing eliminates some hollow spaces in the agglomerate which can fill liquid assets, this loss is more than compensated by the empty space gained by using porous particles.

Examples of materials that can be postdosed to the composition include enzymes, bleaches, bleach precursors, bleach stabilizers, foam suppressors, perfumes and colorants.

Conveniently, solid or porous ingredients, generally inorganic, can be absorbed by the solid porous particles, which can then be post-dried in the composition obtained by the process of this invention.

The process is very flexible with respect to the chemical composition of the starting materials. Phosphate forming compositions as well as zeolite can be made. The process is also suitable for preparing compositions containing calcite / carbonate.

The particulate solid component has an initial particle size of 0.1 to 500 microns, preferably 1 to 350 microns, more preferably 0.1 to 300 microns. Preferably, the solid component comprises from 5 to 95% builders, more preferably from 10 to 80% and more preferred from 20 to 60% by weight.

The neutralized or partially neutralized surfactant may comprise anionic, nonionic or zwitterionic surfactants. The words "partially neutralized" shall mean a surfactant that may be selected from linear alkylbenzene sulfate or C12 to C18 sulfonate, linear alkylbenzene sulfate, alpha olefin sulfate or sulfonate, internal olefin sulfate or sulfonate, sulfate or sulfonate of an acid ester. primary alkyl fatty acid, sulfate or sulphonate, sulfates or sulfonates of primary alcohols and water-soluble salts of the fatty acids, for example tallow or coconut soaps.

The nonionic surfactant can be selected from those compounds produced by the condensation of alkylene oxide groups with an organic hydrophobic compound, for example alcohols or alkyl phenols. Preferred nonionic compounds are the water-soluble condensation products of aliphatic alcohols having from 8 to 30 carbon atoms in the molecule with from 3 to 15 moles of ethylene oxide formaldehyde alcohol. Other nonionic compounds include water-soluble amine oxides containing an alkyl moiety of about 10 to 18 carbon atoms and 2 halves selected from the groups of alkyl and hydroxyalkyl moieties with 1 to 3 carbon atoms and those derived nonionic compounds of sugars, for example alkyl polyglycosides.

Zwitterionic surfactants include derivatives of aliphatic quaternary ammonium sulfonium phosphonium compounds in which one of the aliphatic substituents comprises an anionic group which solubilizes in water.

Preferably, the binder component comprises a mixture of neutralized or partially neutralizing surfactants, for example a mixture of linear or primary alkylbenzene sulphonates containing from 11 to 14 carbon atoms and primary alcohols containing from 12 to 15 carbon atoms ethoxylated with 3 to 7 moles of ethylene oxide formaldehyde alcohol in a weight ratio of anionic compound to nonionic compound of 3 to 1 or a mixture of a primary or secondary alcohol sulfate with 14 to 17 carbon atoms with a primary alcohol with 12 to 15 carbon atoms ethoxylated with 3 to 7 moles of ethylene oxide formaldehyde alcohol in a weight ratio of 2 to 1.

Preferably, the neutralized surfactant comprises less than 20% by weight of water, more preferably less than 10%, more preferred still less than 5% by weight, and is obtained by the method described in US Pat. us. 4-923,636 and 4,826,632 from Blackburn, or the US patent. 4 * 052,342 of Fernle, or the patent E.U.A. 5 * 324,455 from Dumas et al. which are incorporated here as references.

The surfactant content of the binder is preferably from 50% to 100%, more preferably from 55% to 90% and even more preferred from 60% to 80%. Preferred surfactant mixtures contain from 20 to 80% by weight of anionic surfactant and from 20 to 80% by weight of nonionic surfactant and without water.

Preferably the binder component comprises less than 30% by weight of water more preferably between 0.5% and 25% and still more preferred between 5% and 15%.

The high shear mixer advantageously used to carry out the process is preferably a Littleford (MR) FM 130D mixer. This apparatus consists essentially of a large static hollow cylinder with its horizontal longitudinal axis. Along this axis is a rotary shaft with several different types of vanes mounted on it. Preferably, when used to perform the method of the present invention, the tip speed of the shaft is between 1 m / sec and 20 m / sec, more preferably between 1 m / sec. and 12 m / sec. The mixer may be equipped with one or more high speed blades and preferably these are operated at tip speeds from 15 m / sec to 80 m / sec, more preferably from 20 m / sec to 70 m / sec. Other mixers suitable for the process of the present invention are the Lodige (MR), Eirich (MR) RV02, Powrex (MR) VG00, Zanchetta (MR), Schugi (MR) and Fukae (MR) mixers.

In the process according to the invention, the solid component is fed to the mixer followed by the binder component which is either sprayed onto the solid component or pumped into the mixer. The components are mixed for a total residence time preferably 0.2 to 8 min. and more preferably from 0.25 to 5 min. Optimally after that mixing time a coating agent such as zeolite can be added to the mixer and the mixer operated with only the main shaft for 20 to 60 seconds. The granules made by the process preferably have a bulk density of 600 g / 1 to 1150 g / 1 and a particle size (measured by the Rosin-Rammier method) of 300 to 1200 microns, more preferably 400 to 800 microns.

The ratio of binder component to solid component preferably is in a weight ratio of 3: 2 to 2: 3 and more preferably 1: 1 to 2: 3.

The preferred process operates at a temperature from room temperature to 60 ° C, more preferably from room temperature to 40 ° C.

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

In the examples, the abbreviations that follow are used for the materials used: Zeolite: Zeolite 4A (essalith ex Degussa) and Zeolite MAP (ex Crosfield) Carbonate: sodium carbonate G100 (ex FMC) LAS: linear alkyl benzene sulfonate Non-ionic: non-ionic surfactant, ethoxylated alcohol, Neodol 25-7 ex Shell SI 90: smoked silica produced by Cabot and which is fully described in the Boeltín CGEN-8 2/90 Sip 50s: A silicate produced by Degussa and fully described in the Bulletin PT 71-16-1-391-HC.

TABLE 1% SOLID MIXTURE tM 1/1 HAM: combination of I part LAS to 1 part 7E.0 C | 2., 5 highly active mixture of alcohol (non-ionic) < :) 2/1 HAM: combination of 2 parts LAS to 1 part 7E.0 C, 2., 5 highly active mixture of alcohol (non-ionic) p) FP: food processor (4) BL: Lodige load mixer.

Examples 1 to 4 were prepared at a scale of 45 kg (100 lb.) in a Lodige load mixer (Littleford PM 130D1) at high speed or at a small scale of 3-500 gm in a food processor General Model VC- Four. Solids and binders were added to the mixer before the granulation began and the granulation duration was 30 sec. 2 minutes. The granulation stopped when most of the particles appeared between 100 and 500 microns in diameter. The resulting powders flowed freely.

Examples 1, 3 and 4 show formulations in which the level of granule surfactant exceeds 40% by weight. The mixture of solids used, the specific surface areas that result and the amount of active in the product have been reported in Table 1. The specific surface areas were measured in m per gram of particles and the values for a given mixture were calculated on an average weight basis using the BET measured surface areas. The BET surface areas that were used for individual components are listed in Table 2 below.

Example 2 serves as a comparative example to illustrate that a surfactant level of less than 40% is achieved when the solid mixture has a relatively small specific surface area.

Other mixers are also suitable.

TABLE 2 PROPERTIES OF SOLIDS

Claims (10)

R E I V I N D I C A C I O N S

1. - Process for preparing a detergent composition having at least 40% by weight of surfactant and a bulk density of at least 650 g / 1, the process comprises the single step of mixing with high shear until granulated at a temperature in the scale from the ambient temperature up to 60 ° C, a binder component comprising the surfactant and less than 20% water, with a solid particulate component, of initial particle size from about 0.1 to 500 microns; the particulate solid component has at least about 15% by weight of particles with a particle size of at least about 50 microns and a sufficient amount of smaller particles so that the average surface area of the particulate component is at least 9 m / g approximately measured by the BET method and where the binder keeps the mixture in the particulate state throughout the entire process.

2. - Process according to clause 1, wherein the binder comprises from 20 to 80% of an anionic surfactant and from 20 to 80% of a nonionic surfactant.

3. - Process according to clause 1 or 2, wherein the binder component comprises: a) a sodium or potassium salt of an alkyl sulphate or sulphonate in an amount of 20 to 80% by weight; b) a non-ionic alkoxylated surfactant in an amount of 20 to 80% by weight; c) the balance is water in an amount from 0 to less than 20% by weight.

4. - Process according to any of the preceding clauses, wherein the binder comprises less than 10% water.

5. - Process according to clause 1, wherein the binder comprises fatty acid in combination with a stoichiometric amount of alkaline material sufficient to neutralize the fatty acid.

6. - Process according to any of the preceding clauses, wherein the solid component comprises from 5 to 95% by weight of a builder.

1 . - Process according to any of the preceding clauses, wherein the binder and the solid components are mixed until the granules have a diameter of 300 to 1200 microns.

8. - Process according to any of the preceding clauses, wherein the composition comprises binder and solid components in a weight ratio of binder to solid of 3: 2 to 2: 3.

9. - A detergent composition in particles that is obtained directly by a process as defined in any of the preceding clauses.

10. - Composition according to clause 9, which is in a substantially pure form. SUMMARY Process for making a detergent composition having at least 40% by weight of surfactant and a bulk density of at least 650 g / 1, the process comprises the single step of mixing with a high shear stress until granulated at a temperature from room temperature up to 60 ° C, a binder component comprising the surfactant and less than 20% water, with a solid component in particles of an initial particle size of about 0.1 to 500 microns; the particulate solid component has at least about 15% by weight of particles with a particle size of at least about 50 microns and a sufficient amount of smaller particles so that the average surface area of the particulate component is at least 9 m / g approximately, measured by the BET method and where the binder maintains the mixture in a particulate state throughout the entire process.