MX2014012995A - Process for the production of a detergent granule, detergent granule and detergent composition comprising said granule. - Google Patents

Abstract

There is provided a process for the production of a detergent granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof, which comprises the steps of (i) neutralising an anionic surfactant precursor with a source of alkali, (ii) adding Na2SO4 and Na2CO3 to form a slurry and (iii) spray-drying the obtained slurry to form a granule, whereby the molar ratio of Na2SO4 to Na2CO3 is in range of 1 : 0.9 to 1 : 1.3, and whereby the double salt Na2SO4.Na2CO3 is formed and whereby the slurry comprises a polycarboxylate polymer. There is also provided a spray-dried detergent carrier granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof, comprising (i) linear alkylbenzene sulphonate (LAS), soap and mixtures thereof, and (ii) the double salt Na2SO4.Na2CO3 obtainable by the process of the present invention. A third aspect is a detergent composition comprising such granules.

Description

PROCESS FOR THE PRODUCTION OF A GRANULO DE DETERGENT, DETERGENT GRANULATE AND COMPOSITION OF DETERGENT BUY BY SENDING SAID GRANULO TECHNICAL FIELD OF THE INVENTION The present invention relates to the field of detergent powders, especially laundry detergent powders and their production. More particularly, it relates in a first aspect to a process for the production of a detergent granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof. In a second aspect, the invention relates to a detergent granule comprising at least 40% by weight of an anionic surfactant and which is obtainable by said process. In a third aspect, the invention relates to detergent compositions comprising such granules.

Background This invention relates to the production of detergent granules comprising a surfactant system that gives effective washing. In particular, the invention relates to a process for producing such granules by spray drying an aqueous suspension.

It is well known to prepare granular detergent products or powders by spray drying of aqueous suspensions. Such processes comprise the steps of preparing an aqueous suspension comprising from 20 to 60% by weight of water, followed by atomizing the suspension under high pressure to form droplets and then drying them in a counter-current spray-drying tower. Typical tower entry and outlet temperatures are from 250-400 ° C and 80-120 ° C, respectively.

For example, EP-A-1 914 297 describes a process for the preparation of a spray-dried detergent powder having a bulk density of 426 g / l or less, wherein the spray-dried detergent powder comprises an anionic detersive surfactant. and from 0% to 10% by weight of zeolite former and from 0% to 10% by weight of phosphate former, and wherein the process comprises the step of: (a) preparing an aqueous suspension suitable for spray drying comprising from 30% to 60% by weight of water and from 40% to 70% by weight of non-aqueous material, wherein the non-aqueous material comprises an inorganic component and a component organic, wherein the weight ratio of the inorganic component to organic component is in the range from 0.3: 1 to 5: 1; Y (b) atomizing the suspension in a spray-drying tower, wherein the temperature of the suspension as it enters the spray-drying tower is in the range from 65 ° C to 140 ° C, and where the air temperature The output of the spray-drying tower is in the range of 70 ° C to 120 ° C, and wherein the non-aqueous material comprises anionic surfactant, polymeric carboxylate and carbonate salt.

EP-A-221 776 discloses a process for the production of a porous, zero-phosphate powder, suitable for use as a base for a granular detergent composition or a component thereof and capable of absorbing and retaining substantial amounts of liquid. fluid liquid liquefiable detergent components or components, said process comprises the steps of (i) preparing an aqueous suspension comprising sodium carbonate, and optionally also comprising sodium sulfate, (ii) drying the suspension to form a powder, the process being characterized in that the total amount of sodium carbonate and (if present) sodium sulfate is at least 20 weight percent based on the dry powder, the weight ratio of sodium carbonate to sodium sulfate (when is present) in the suspension is at least 0.37: 1, and from 0.1 to 60 weight percent, based on the total amount of sodium carbonate and (if present) sodium sulfate in the dry powder, of a mod Glass growth enhancer, which is a polymeric polycarboxylate which is incorporated in the suspension not after the sodium carbonate, whereby it is formed in the modified burkeite suspension in crystal growth and / or modified sodium carbonate monohydrate in growth. crystal glass.

These processes can be advantageously used to prepare spray-dried detergent powders having a low bulk density, a low content of anionic surfactants. However, it is difficult to prepare detergent powders having an anionic detergent content of 40% by weight or greater. A further increase in anionic detergent content leads to a poor drying rate due to the high suspension moisture content of about 40-50% by weight. The high drying temperatures required to dry the excess water cost extra energy and can lead to fire incidents in the tower and / or drying cyclones. High anionic detergent suspensions can also cause overflow and have transportation problems due to aeration and very high viscosity.

The resulting high anionic detergent powders usually have a low bulk density and are difficult to handle and store and have higher packing costs.

Moreover, spray drying is an intense process in energy and it would be interesting from an environmental point of view, to improve the current detergent manufacturing technology in this regard. The environmental aspects of detergent manufacturing processes are considered important, not only by manufacturers but also by consumers who are increasingly interested in the sustainability of our economic activities.

Therefore, a first objective of the present invention is to provide a more energy-efficient process for preparing spray-dried detergent granules having an anionic detergent content above 40% by weight or greater that does not have the aforementioned disadvantages. . In particular, the detergent granules should have good powder properties.

A further objective of the present invention is to provide a more energy efficient process for preparing spray dried (laundry) detergent powders having an anionic detergent content above 40% by weight or greater that does not have the aforementioned disadvantages.

We have now found, surprisingly, that the spray-dried detergent granules having an anionic detergent content above 40% by weight or greater can be prepared from a paste comprising Na2SO4 and Na2CO3, wherein the molar proportion of Na2S04 to Na2C03 is in the range of 1: 0.9 to 1: 1 .3, and therefore the double salt Na2S04 is formed. Na2C03.

In this way, these and other objectives can be achieved by the process according to the invention, which comprises the steps of (i) neutralizing an anionic surfactant precursor with an alkali source, (ii) adding Na2CO3 and Na2SO4 to form a paste and (iii) spray-drying the obtained suspension to form a granule, whereby the molar ratio of Na2S04 to Na2CO3 is in the range of 1: 0.9 to 1: 1 .3, and therefore the double salt Na2S04 . Na2C03 is formed, and whereby the suspension comprises a polycarboxylate polymer.

BRIEF DESCRIPTION OF THE INVENTION According to a first aspect of the present invention, there is provided a process for the production of a detergent granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof, which comprises the steps of (i) neutralizing an anionic surfactant precursor with an alkali source, (ii) add Na2SO4 and Na2CO3 to form a suspension and (iii) spray-dry the suspension obtained to form a granule, whereby the molar ratio of Na2SO4 to Na2CO3 is in the range of 1: 0.9 to 1: 1.3; and whereby the double salt Na2S04 is formed. Na2C03, and whereby the suspension comprises a polycarboxylate polymer.

According to a second aspect of the present invention, there is provided a spray-dried detergent granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof, comprising (i) linear alkyl benzene sulfonate (LAS), soap and mixtures thereof, and (ii) the double salt Na2S04. Na2C03 obtainable by the process of the present invention.

According to the third aspect of the present invention, a detergent composition comprising the granules according to the present invention is provided.

Detailed description of the invention The first aspect of the present invention is a process for the production of a detergent granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof. In a first step of this process, an anionic surfactant precursor is neutralized with an alkali source to form a paste of surfactant The anionic surfactant precursor is an acid precursor of a non-anionic soap surfactant which, when reacted with an alkali source, will be neutralized to form a salt of the anionic surfactant.

Precursors of anionic surfactants in liquid, pumpable form are preferred. The anionic surfactant precursor is preferably selected from the alkyl benzene sulfonic acid, fatty acid and mixtures thereof. The linear alkyl benzene acid is also referred to as LAS and H LAS. The LAS acid produces the corresponding linear alkyl benzene sulfonate (LAS) on neutralization. Preferably, the non-soap LAS anionic surfactant has an alkyl chain length of C 8-1 8, more preferably C 10-16 and most preferably C 2-14.

The soaps formed by the neutralization of fatty acids or carboxylic acids can be used as secondary anionic surfactants in mixture with the non-soap anionic surfactants. Preferred carboxylic acids are fatty acids with 1 2-1 8 carbon atoms, such as, for example, fatty acids from coconut oil, palm oil, palm kernel oil and tallow. The fatty acids can be saturated or unsaturated, branched chain or linear. Mixtures of fatty acids can be used. Fatty acids can be used at levels up to 30% by weight based on the anionic surfactant precursor.

The anionic surfactant precursors (or mixture of surfactant precursors) can be used in a partially pre-neutralized form without complete loss of the advantageous effects of the invention. In effect, the surfactant acid is then a mixture of the surfactant acid with non-neutralized ammonium soap surfactant.

The anionic surfactant precursors can be added in admixture with other components. Suitable components are neutralized anionic surfactants, for example, the salts of half-esters of alkyl and / or alkenyl sulfuric acid (ie, the sulfation products of primary alcohols), which give alkyl and / or alkenyl sulfates upon neutralization. Among such non-soap anionic surfactants is the primary alcohol sulfate (PAS), especially PAS having a chain length of C 10-22, preferably C 12-14. Coco PAS is particularly desirable.

Other suitable surfactant acids include alpha-olefin sulphonic acids, internal olefin sulfonic acids, sulfonic acid esters of fatty acids and primary sulfonic acid. It is also possible to use combinations of surfactant acids as will be apparent to the skilled person.

Among the other components, besides the fatty acids and neutralized anionic surfactant already discussed, the most important additional component that can be added as liquids with the surfactant precursor is the nonionic surfactant. It is usually added to the surfactant acid to reduce the viscosity to allow it to be added at a lower temperature.

Suitable non-ionic surfactants that can be used include the ethoxylates of primary and secondary alcohols, especially the C8-C20 aliphatic alcohols ethoxylated with an average from 1 to 50, preferably 1 to 20, moles of ethylene oxide per mole of alcohol, and more especially the primary and secondary aliphatic alcohols ethoxylated with an average from 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkyl polyglycosides, glycerol monoethers and polyhydroxyamides (glucamide). As discussed, the already neutralized anionic surfactant can be mixed with the surfactant acid. This can have the advantage of increasing the performance of the overall process.

Other liquid additives that can be added with the anionic surfactant precursor, or added as a separate liquid stream or stream, include inorganic acids, such as sulfuric acid, and hydrotropes, such as toluene sulfonic acid.

The alkali source which is reacted with the anionic surfactant precursor can be any suitable alkali source, in liquid or solid form. Examples are aqueous solutions of alkali metal hydroxides, preferably sodium hydroxide solutions, or sodium carbonate. Particularly preferred are concentrated aqueous sodium hydroxide solutions of approximately 50% by weight. The amount of water should be kept to a minimum, because the water will have to be dried in the subsequent spray drying step. On the other hand, it should not be so low that the neutralized surfactant paste is too viscous to handle.

Sodium carbonate can be of any type. It has been found that synthetic light soda ash is especially preferred; natural heavy soda ash is intermediate, while synthetic granular soda ash is the least preferred raw material.

The surfactant paste is preferably prepared in a stirred mixer provided with an open steam coil to heat the dough to a temperature of about 35-40 ° C. The neutralization reaction between the anionic surfactant precursor and the alkali source produces a concentrated surfactant paste, which preferably has a solids content of between 60 to 80% by weight. The heat of neutralization causes the temperature to rise from about 35-40 ° C to about 75-80 ° C, where it is maintained. It is beneficial to allow a few minutes of additional time to ensure complete neutralization.

In a second step of the process, sodium sulphate (Na2S04) and sodium carbonate (Na2C03) are added to the surfactant paste to form a paste. It is not believed that the order of addition is essential.

Additionally, the pulp comprises a polycarboxylate polymer. For example, the polycarboxylate and alkali silicate copolymer can be pumped into the mixer with increased agitation speed to improve the total mass flow. The alkali metal silicates having a proportion of SiO2 / M20, wherein M is sodium ion, from 1.5 to 3.3, preferably from 1.8 to 2.6, are favorably used.

Among the polycarboxylate polymers, polyaspartates and polyaspartic acid are advantageously used because of their biodegradability. Polymeric polycarboxylates are used in amounts from 0.1 to 20% by weight, preferably from 0.2 to 5% by weight, most preferably 1 to 5% by weight, based on the total amount of sodium carbonate. However, higher levels of polymer, for example, up to 30% by weight based on sodium carbonate, can be present in detergent granules of the invention, or complete compositions comprising the granules of detergents of the invention, for other reasons , for example, training, structuring or anti-redeposition.

The polycarboxylate polymer preferably has a molecular weight of at least 1,000, advantageously from 1,000 to 300,000, in particular from 1,000 to 250,000. Polycarboxylates having a molecular weight from 1,000,000 to 70,000 are especially preferred. All molecular weights cited herein are those provided by the manufacturers.

Preferred polycarboxylates are homopolymers and acrylic acid or maleic acid copolymer. Of particular interest are polyacrylates and copolymers of acrylic acid / maleic acid. Suitable polymers, which may be used alone or in combination, include the following: The salts of polyacrylic acid, such as sodium polyacrylate, for example, Versicol (trademark) E5 E7 and E9 examples of Allied Colloids, average molecular weights of 4000, 27000 and 7000; Narlex (trademark) LD 30 and 34, examples of National Adhesives and Resins Ltd, average molecular weights of 5000 and 25000 respectively; and Sokalan range (trademark) PA examples of BASF, average molecular weight of 250000; ethylene / maleic acid copolymers, for example, the EMA series (trademark) example of Monsanto; copolymers of methyl vinyl ether / maleic acid, for example Gantrez (trademark) AN 1 19 eg GAF Corporation; copolymers of acrylic acid / maleic acid, for example, Sokalan (Trade Mark) CP, example BASF.

A second group of polycarboxylate polymers comprises polyaspartic acids and polyaspartates. Poliaspartate is a biopolymer synthesized from L-aspartic acid, a natural amino acid. Due in part to the carboxylate groups, the polyaspartate has properties similar to polyacrylate. A preferred type of polyaspartate is thermal polyaspartate or TPA. This has the benefit of being biodegradable for environmentally benign products, such as carbon dioxide and water, which avoids the need for removal of TPA during wastewater treatment, and its disposal to landfill. PTA can be made by first heating aspartic acid to temperatures above 1 80 ° C to produce polysuccinimide. Then, the polysuccinimide is ring-opened to form polyaspartate. Because the ring can be opened in two possible ways, two polymer bonds are observed, an [alpha] -link and a [beta] -link.

Mixtures of any two or more polymers, if desired, can be used in the process and detergent granule compositions of the invention.

In a third subsequent step of the process of the invention, the suspension obtained is spray-dried to form a granule, whereby the molar ratio of Na 2 SO 4 to N 2 CO 3 of sodium is in the range of 1: 0.9 to 1: 1.3. and for which double salt Na2S04. Na2C03 is formed. It is believed that the double salt Na2S04. Na2C03 contributes in a favorable manner to the high specific surface area ("SSA") of the granules, which in turn allows them to carry liquid components, such as fatty / non-ionic acid mixtures.

The tower inlet and outlet temperatures typical of the spray drying process are from 250-400 ° C and 80-120 ° C, respectively.

The detergent granule A second aspect of the present invention is a spray-dried detergent granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof. The granules have a relatively high specific surface area, which makes them suitable as carriers for absorbing liquid components, such as nonionic surfactants or mixtures of nonionic surfactants / fatty acids.

The granule according to the invention comprises. (i) an alkali metal salt of a non-soap detergent, soap and mixtures thereof, and (ii) the double salt Na2S04. Na2C03, and is obtainable by the process according to the invention. Preferably, the alkali metal salt of a non-soap detergent is linear alkyl benzene sulfonate (LAS).

The spray-dried detergent granule of the invention is a particulate solid with a bulk density in the range of 350 to 800 g / liter. The particle size distribution is generally such that at least 50% by weight, preferably at least 70% by weight and more preferably at least 85% by weight, of the particles are smaller than 1,700 microns, and the Fine level is low. It has generally been found that no additional treatment is necessary to remove either oversized or fine particles.

The spray-dried detergent granule is further characterized by its specific surface area, as measured by nitrogen adsorption. The specific surface area ("SSA") of the granules is measured by nitrogen absorption according to the ASTM D 3663-78 standard based on the Brunauer, Emmett and Teller (BET) method described in J. Am. Chem. Soc. 60, 309 (1 938). We use a Gemini Model 2360 surface area analyzer (available from Micromeritics I nstrument Corp. of Norcross, Ga.). The spray-dried detergent granule has a specific surface area (SSA) of 5 m2 / g or greater, preferably 8 m2 / g or greater, even more preferably 10 m2 / g or greater.

The granule obtained generally has excellent flow properties, low compressibility and low tendency to cake formation. The particulate detergent granules which are the direct result of the spray drying process have an anionic surfactant content of at least 40% by weight. There is no need for a granulation aid, such as zeolite, although it is possible to use them. It is possible to achieve exceptionally high levels of anionic surfactant in the granule. For example, more than about 45% by weight, preferably more than 50% by weight, or about 50% by weight of anionic surfactant can be incorporated in the detergent granule. It is preferred that the anionic surfactant comprises at least 10% by weight of soap, based on the total anionic surfactant in the detergent granule.

The detergent granules may also comprise water in an amount of 0 to 8%, and preferably 0 to 4% by weight of the granules. The detergent granules obtained from the process are stable in storage at high humidity levels. Thus, they can be used in a wide range of detergent products.

Desirably, the detergent granules have an aspect ratio not in excess of two and more preferably are generally spherical in order to reduce the segregation of other particles in a formulated powder detergent composition and to improve the visual appearance of the powder .

The presence of the double salt Na2S04.Na2C03 can be detected using X-ray diffraction techniques that are known in the art. X-ray diffraction (XRD) is a non-analytical method destructive to measure the diffraction angles and characteristic intensities of a periodically ordered material (crystalline material). The spatial distributions and intensity of the scattered X-rays form a specific diffraction pattern, which is the "footprint" of the sample and can be used for qualitative and quantitative evaluation, calculation of d-value, determination of crystallite size and defects by the peak shape and polymorphism.

The detergent composition A third aspect of the present invention is a detergent composition, especially a laundry detergent composition, comprising the granules according to the present invention.

The spray-dried detergent granules of the present invention can be used as such, but can also be supplemented with other detergent ingredients, components or additives to form a complete detergent composition. The detergent granules can be mixed with anything normally used in detergent formulations. They can be mixed dry with solid materials and can advantageously have additional liquids added to them, using their capacity to carry surplus liquids. It is especially advantageous to add conventional, or even higher than conventional, levels of perfume in this form.

Other types of non-soap surfactants, for example, cationic, zwitterionic, amphoteric or semi-polar surfactants, may also be used with the granules if desired. Many suitable active detergent compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volume I and I I, by Schwartz, Perry and Berch.

The soap may also be present, to provide additional foam control and detergency and forming powder. The fully formulated composition can comprise up to 8% by weight.

Fully formulated detergent compositions including the detergent granules prepared by the process of the invention, may contain conventional amounts of other detergent ingredients, for example, bleaches, enzymes, foam boosters or foam controllers as appropriate, anti-aging agents. redeposition, such as cellulosic polymers; aincrustation agents, perfumes, dyes, matting agents, fluorescent agents, sodium silicate; corrosion inhibitors including silicates; inorganic salts such as sodium sulfate, enzymes; colored specks; foam controllers; and fabric softening compounds: the detergent granule can be mixed, if desired, with other organic or inorganic formers, usually supplied in the form of granules of either pure former or mixtures of former and other ingredients. Especially preferred organic formers are acrylic polymers, more especially acrylic / maleic copolymers, suitably used in amounts from 0.5 up to 15% by weight, preferably from 1 to 10% by weight. Such polymers can also fulfill the function of the habit modifying polymer.

The detergent granules of the present invention are hereinafter referred to as a base powder. They can be mixed with another powder obtained from any conventional detergent production process including spray drying or non-spray drying processes. As the detergent granules produced by the present invention can be mixed with these other powders, a significant degree of formulation flexibility is obtained and the level of active material in the fully formulated composition can be very high without an unnecessary increase in the levels of trainer The total amount of surfactant present in the fully formulated detergent composition is suitably from 1 to 70%, although amounts outside this range can be employed as desired The detergent granules can usually form from 30 to 100% by weight of a final fully formulated detergent composition. Normally, the fully formulated detergent composition incorporating the detergent granules produced by the process of the invention can comprise from 15 to 60% by weight, preferably 20 to 50% by weight of anionic surfactant, this anionic surfactant is completely derivatized or part of the granular product of the spray drying process. In addition, the fully formulated detergent composition can comprise from 0 to 35% by weight of nonionic surfactant, and from 0 to 5% by weight of fatty acid soap.

Fully formulated detergent compositions, comprising other ingredients and detergent granules produced according to the invention, preferably have a bulk density of about 50 to 750 g / liter, more preferably at least 450 g / liter.

Fully formulated detergent compositions may also include other desired solid ingredients for inclusion in the detergent powder, eg, fluorescent; polycarboxylate polymers; anti-redeposition agents, for example, sodium carboxymethyl cellulose; or fillers such as sodium sulfate, diatomaceous earth, calcite, kaolin or bentonite.

If desired, solid particulate surfactants, for example, alkylbenzene sulfonate and / or alkyl sulphate in powder form, can be part of the charge of solids to the mixer to additionally increase the level of surfactant activity in the granules, without However, it is preferred to produce all of the anionic surfactant by spray drying.

The process is generally not sensitive to the type of mixer used, provided intensive mixing is applied. We have found that to obtain the full advantages of the invention, the use of a mixer with a chopping action can be advantageous.

Preferably, the mixing is performed in a mixer having and using both a stirring action and a cutting action, most preferably these actions will be usable separately, as described below. The cutting action is the chopping action is preferred. This can be advantageously achieved by the choice of mixer to be a high speed mixer / granulator having both a stirring action and a cutting action. Preferably, the high-speed mixer / granulator has rotating cutters and agitators that can be operated independently of one another, and at variable or separate speeds.

Such a mixer is capable of combining a high energy stirrer inlet with a cutting action, but it can also be used to provide other milder stirring regimes with or without the cutter in operation. A Lódige mixer is preferred, vertical or horizontal axis cutters are desirable for high anion loading. Mixers of the Fukae FS-G type manufactured by Fukae Powtec Co Ltd., Japan are also preferred.; this apparatus is essentially in the form of a bowl-shaped container accessible via an upper port, provided with wax from its base with an agitator having a substantially vertical axis and a cutter positioned on a side wall. The agitator and cutter can be operated independently of one another, and at variable speeds separately. The container can be cooled.

Other mixers that are believed to be suitable for use in the process of the invention are the Fuji (trademark) VG-C series, eg from Fuji Sangyo Co., Japan; and Roto (trademark), eg Zanchetta & Co srl, Italy.

Still another mixer found suitable for use in the process of the invention is the batch mixer Lódige series (trademark) FM, eg Morton Machine Co., Ltd., Scotland. This differs from the aforementioned mixers because its agitator has a horizontal axis. Z-shaped and sigma blade mixers (Winkworth Machinery Limited) are suitable mixers having a chopper action.

The invention will be further described with reference to the following non-limiting examples. In the examples, bulk density (BD), dynamic flow rate (DFR) and unconfined compression test (UCT) are measured according to the following known test protocol.

Bulk density (BD) The bulk density properties in the present specification are measured by a method according to JIS K 3362.

Dynamic flow rate (DFR) This is also called flow velocity. The powder flow can be quantified by means of the dynamic flow rate (DFR) in ml / s, measured by the following procedure. The apparatus used consists of a cylindrical glass tube having an internal diameter of 40 mm and a length of 600 mm. The tube is held securely in a position so that its longitudinal axis is vertical. Its lower end is terminated by means of a soft cone of polyvinyl chloride having an internal angle of 1 5 ° and a lower outlet hole of diameter of 22.5 mm. A first beam sensor is positioned 1 50 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 exit orifice is temporarily closed, for example, when covering with a piece of cardboard, and the powder is emptied through a funnel in the upper part of the cylinder until the powder level is about 1 0 cm higher than the upper sensor; a separator between the funnel and the tube ensures that the filling is uniform. The output then opens and the time t (seconds) taken by the dust level to fall from the upper sensor to the lower sensor is measured electronically. The measurement is usually repeated two or three times and an average value is taken. If V is the volume (mi) of the tube between the upper and lower sensors, the dynamic flow rate DFR (ml / s) is given by the following equation: DFR = V ml / s t Unconfined compression test (UCT) In this test, the newly produced powder is compressed into a Compact and the force required to break the compact is measured. The powder is loaded in a cylinder and the surface is leveled. A 50 g plastic disc is placed on top of the powder and a 10 kg weight plunger is slowly placed on top of the disc and allowed to remain in position for 2 minutes. The weight and plunger are then removed and the cylinder is carefully removed from the powder to leave a self-supporting powder cylinder with the 50 g plastic disc on top of it. If the compact breaks, a second 50 g plastic disc is placed on top of the first and left for approximately ten seconds. Then if the compact is still broken, a 1 00 g disk is added to the plastic discs and left for ten seconds. The weight is then increased in increments of 0.25 kg at 1 0 second intervals until the compact collapses. The total weight (w) necessary to effect the collapse is noted.

The cohesiveness of a powder is classified by weight (w) as follows: W < 1 .0 kg flows well 1 .0 kg < w < 2.0 kg flows moderately 2. 0 kg < w < 5.0 kg cohesive 5. 0 kg < Very cohesive w Examples Example 1 An aqueous paste was prepared in a stirred mixer provided with an open steam coil to heat the dough. 2, 500 kg of a suspension were prepared involving the following steps.

A charge made of clean water (523 kg) and caustic soda solution (1 92 kg) of 50% purity was dosed to the mixer and heated to a temperature of 40-40 ° C. Following this step, a pre-weighed quantity (732 kg) of commercial grade sulfonic acid was dosed gradually over a period of 3-4 minutes with continuous agitation to form a neutralized pulp. An additional 2 minutes was allowed to ensure that the neutralization reaction was completed. The preheated alkali silicate (1 69 kg) and copolymer (1 14 kg) were pumped into the mixer with increased agitation speed, in order to improve the flowability of the total mass. In this step, it may be preferred to maintain temperature at 75-80 ° C by using steam in open coil. Following this step, the steam valve was closed and sodium sulphate (326kg) / sodium carbonate (228kg) was dosed together with minors (0.91kg fluorescent and sodium carboxymethylcellulose (SCMC) 16.3kg) via an adjusted screw conveyor to be dosed for a period of 2-3 minutes and the agitator speed was raised to 70-75 rpm. When the solids are dosed, they fall near the agitator blades to prevent build-up on the wall or the formation of lumps. In different examples, the solids were dosed in different sequences to promote the formation of crystalline phases after care was taken to ensure that good dispersion / dissolution was achieved. HE allowed a final mixing step for another 2 minutes, and then the mixed mass was discharged to the holding tank for subsequent operation in the spray-drying tower.

In all the examples, the previous loading sheet was calculated for several formulations and was used to make the suspensions. The suspensions were transported by means of a low pressure pump, Reitz magnetic mill / separator and then to the HP pump. The suspension was sprayed in a spray dryer with a diameter of 2.5 by the use of two spray system nozzles to achieve the desired performance speed of 1 100-1 200 kg / h of suspension at pressures of 25 bars (25x105 Pa) . The tower was heated by hot air maintained at temperatures of 270-290 ° C in countercurrent mode and the dry powder was collected at the bottom of the tower. The dust moisture content was controlled in the range of 2-3% and minor variations in air inlet temperature were required to maintain steady state conditions.

The powder properties were examined as follows and a non-ionic / additional fatty acid mixture was atomized onto the tower base powder (indicated by% active loaded) to give a detergent product having excellent powder properties. active charged: 7.6% max active loaded: 7.0% max % of asset loaded: 7.0% max % of active loaded: 5.6% max Example 2 These base powders of Example 1 were also examined for the presence of crystalline phases. Using the D8 Discover machine eg Bruker-AXS machine, the d values of the diffraction lines of the samples were obtained and from them the crystalline compounds were identified.

Materials and methods: The results are given in the table below: The presence of crystalline compounds in base powders "+" indicates the presence of a crystalline compound "-" indicates that a crystalline compound, if present, is below the detection limit of the XRD method used.

Claims (17)

1. REIVI NDICATIONS 1 . The process for the production of a detergent granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof, which comprises the steps of (i) neutralizing a precursor of anionic surfactant with an alkali source, (ii) adding Na2SO4 and Na2CO3 to form a suspension and (iii) spray drying the obtained suspension to form a granule, whereby the molar ratio of Na2SO4 to Na2CO3 is in the range of 1: 0.9 to 1: 1 .3, and whereby the double salt Na2S04 is formed. Na2C03 and whereby the suspension comprises a polycarboxylate polymer. 2. The process according to claim 1, wherein the anionic surfactant precursor is selected from linear alkyl sulfate acid (LAS), fatty acid and mixtures thereof. 3. The process according to any preceding claim, wherein the anionic surfactant precursor is LAS acid. 4. The process according to any preceding claim, wherein the suspension comprises amorphous silicate. 5. The process according to claim 1, wherein the polymer is selected from acrylic acid homopolymers, acrylic acid / maleic acid copolymers and acrylic phosphinates. 6. The process according to claim 5, characterized in that the polymer is sodium polyacrylate. 7. The process according to claim 6, characterized in that the polymeric polycarboxylate has a molecular weight in the range from 1,000 to 250,000, preferably in the range from 3,000 to 1,000,000. 8. The process according to any preceding claim, wherein the granule is characterized as having a specific surface area of 5 m2 / g or greater, preferably 8 m2 / g or greater, even more preferably 1 0 m2 / g or greater. 9. A spray-dried detergent granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof, comprising (i) an alkali metal salt of a non-soap detergent, soap and mixtures thereof, and (ii) the double salt Na2S04. Na2C03 obtainable by the process according to any preceding claim. 1 0. The detergent granule according to claim 9, wherein the non-soap detergent is linear alkyl benzene sulfonate (LAS). eleven . The detergent granule according to any of claims 9-1 0, characterized by having a specific surface area of 5 m2 / g or greater, preferably 8 m2 / g or greater, even more preferably 1 0 m2 / g or greater. 12. The detergent granule according to any of claims 9-1, characterized in that the level of anionic surfactant in the granule is greater than 45% by weight, even greater than 50% by weight and preferably even greater than 60% by weight. weight. 1 3. The detergent composition comprising the granules according to any of claims 9-1 2. 14. The detergent composition according to claim 1, which further comprises soap and / or non-ionic surfactant. The detergent composition according to any of claims 1 3-14, further comprising a bleaching system. 16. The detergent composition according to claim 1, wherein the bleaching system is TAED / percarbonate. 17. The detergent composition according to any of claims 1 3-16, further comprising, fluorescent, preferably at a level of 0.05 to 0.5% by weight. 1 8. The detergent composition according to any of claims 1 3-1 7, further comprising perfume. SUMMARY A process is provided for the production of a detergent granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof., which comprises the steps of (i) neutralizing an anionic surfactant precursor with an alkali source, (ii) adding Na2SO4 and Na2CO3 to form a suspension, and (iii) spray drying the obtained suspension to form a granule, which the molar ratio of Na2S04 to Na2C03 is in the range of 1: 0.9 to 1: 1 .3, and for which the double salt Na2S04 is formed. Na2C03 and whereby the suspension comprises a polycarboxylate polymer. A spray-dried detergent-containing granule comprising at least 40% by weight of an anionic surfactant and suitable for use as a granular detergent composition or a component thereof, comprising (i) linear alkylbenzene sulfonate (LAS) is also provided. ), soap and mixtures thereof, and (ii) the double Na2S04 salt. Na2C03 obtainable by the process of the present invention. A third aspect is a detergent composition comprising such granules.