FR2712298A1 - Particulate detergent composition with low content of fine particles. - Google Patents

Abstract

The invention relates to a particulate detergent composition comprising a surfactant and a builder and having a particle porosity of not more than 10% of the pore volume, wherein the particle size distribution of the particles is such that not more than 10% of the particles have a particle size. particle size not exceeding 180 mum, as well as a kneading / densification process to produce it.

Description

This invention relates to a detergent composition and, in

  particular, to a particulate detergent composition having a small proportion of fine particles. The use of detergent compositions for washing laundry in a washing machine generally requires introducing the detergent composition into the wash by means of a dispensing device. Typically, washing machines are provided with an integrated dispenser drawer into which the dose of detergent can be introduced, then the contents of the drawer are emptied with water and sent to the washing compartment. Distribution devices are also known which are placed in the washing compartment of the washing machine and

  from which the detergent composition is dispensed.

  It is desirable that the detergent composition be dispensed in the wash without leaving significant deposits in the dispensing device. Poor dispensing is undesirable, as it results in wasted powder, inaccuracy in the amount of powder reaching washing, leading to ineffective washing cycle, an unsightly residue in the dispensing device and the need to clean the device between two washes. In general, a residue of more than about 10% of the dose of powder introduced is considered to be unacceptable and a residue of less than

about 5%.

  Distribution problems have been encountered mainly in the use of high bulk detergent powders. It is believed that the low porosity of the particles of these powders can exacerbate distribution problems. In addition, the temperature of the wash water can affect the distribution properties of the powder, in particular more residue may remain at low temperatures of the wash water. Wash water temperatures below 'C and, in some cases, below 10' C are used, and it is desirable that the powder is satisfactorily distributed at these temperatures, as well as at low pressure d 'water. Detergent compositions can be produced by a spray drying process, but powders of high bulk density are generally produced by a process involving mechanical kneading, as described, for example, in EP 367,339 (Unilever). The product

  of such a kneading process is here called basic powder.

  Other constituents can be mixed with the powder of

  base to give a fully formulated detergent product.

  It has been found that it is possible to obtain powders with a high bulk density having excellent distribution properties by limiting the particle size distribution of the base powder so that the proportion of fine particles does not exceed a specified value. Consequently, the first object of the invention is a particulate detergent composition having a high bulk density, comprising a surfactant and an adjuvant and having a particle porosity not exceeding

  % of the pore volume, in which the particle size distribution

  particle metric is such that no more than 10% of

  particles have a particle size not exceeding 180 µm.

  Preferably, the detergent composition is mixed with another compound to provide a detergent product

fully formulated.

  The detergent composition advantageously has an apparent density of at least 750 g / l and, preferably, at least 800 g / l. Preferably, the particles have a porosity not exceeding 8% of the pore volume. The porosity is optimal between 3 and 8% of the pore volume, to provide a desirable combination between

  distribution properties and dissolution properties.

  The porosity of the particles is advantageously

  determined using a mercury porosimeter.

  Preferably, the particle size distribution of the powder is such that no more than 5% of the particles have a particle size not exceeding 180 μm. It is also preferred that the composition does not comprise a significant proportion of large particles, which can be called "oversized" particles. Preferably, the particle size distribution of the powder is such that not more than 10% and, preferably, not more than 5%, of the particles have a particle size exceeding 1400 μm and, advantageously,

that it does not exceed 1000 µm.

  Advantageously, the detergent composition has an average particle size of 200 to 1,300 μm, preferably of

  400 to 1000 mm and, in particular, from 500 to 750 pm.

  The composition can be in powder form or in a

  granular form, as desired.

  Advantageously, the distribution characteristics of a composition according to the invention leave a residue of less than 10% and, preferably less than 5%, of the dose of powder introduced into a PHILIPS AWB 126/127 dispenser, at a temperature water of 20 C, preferably 10 C,

  and at a water flow rate of 5 liters per minute for 1 minute.

  The powders according to the present invention are advantageously such that excellent distribution is obtained, in order to allow the powder to be dosed correctly in the wash, thus avoiding significant waste and reducing the need to clean the dispensing device. A second object of the invention is a process for preparing a detergent composition having an apparent density exceeding 750 g / l, which comprises mixing the constituents of the composition to form particles and densifying the particles, so that the particles have a porosity not exceeding% of the pore volume, and classifying the particles so that no more than 10% of the particles have a particle size not exceeding 180 µm. The constituents of the composition can be mixed and densified in the same device or in separate devices. The process can be, as desired,

continuous or discontinuous.

  Preferably, the constituents of the composition are mixed in a high shearing stage, for example in a LODIGE CB30 recycling mixer, for a period of from 30 seconds, and the mixing speed in the apparatus is advantageously from 100 to 2,500 revolutions / min, depending on the degree of densification and the grain size required. A granulation step can optionally be used and implemented with a mixer at low speed, in a moderate shearing step, for example a Plowshare LODIGE KM300 mixer, for a period of 1 to 10 minutes and at a mixing speed of 40. at 160 rpm in the device. It is possible to use a process

  discontinuous, for example in a FUKAE mixer.

  Other mixing devices, in particular those produced by Drais Schrugi, can possibly be

employees.

  The constituents of the composition can comprise individual constituents, particles which comprise several constituents, which are called additives here and / or particles of a spray-dried powder. The process can therefore be a process which is not carried out in a tower, in which no spray drying step is used, or alternatively a process after a tower, in which the constituents of the composition which are mixed and densified include the product of a

  spray drying process.

  The particles can be classified by any suitable means, for example by sieving. It is further preferred that after kneading and densification, the particles are dried and / or cooled, preferably in a fluid bed. Advantageously, the fluid bed is used to eliminate the excessive proportions of fine particles in the powder. In particular, when a drying or cooling step is used, an elutriation of the fine particles can be carried out, since the lower temperature and / or humidity of the powder can increase

  the efficiency of removing fines.

  If necessary, the fine particles which are eliminated from the composition can be recycled to the kneading and / or densification step to give a proportion

fines not exceeding 10%.

  Other constituents can be added after the fact to the compositions according to the invention, in order to give a fully formulated product, as required, which must have a particle size distribution such that not more than 10% of the particles have a particle size not exceeding pm . The detergent compositions according to the present invention generally contain a surfactant and an adjuvant, and may also contain bleaching compounds and other active substances to improve performance and properties. The surfactant can be chosen from soaps and non-saponaceous surfactants of the anionic, nonionic, amphoteric, cationic and / or zwitterionic type. Anionic surfactants, for example alkylbenzenesulfonates, where the alkyl group is linear,

  primary and secondary alkyl sulfates, olefins

  sulfates, fatty acid estersulfonates and alkyl ether sulfates, and nonionic surfactants, for example primary and secondary alcohol ethoxylates, alkylpolyglycosides and glycerol monoethers, are preferred. Suitable examples are described in the literature, for example "Surface active agents and

  Detergents ", volumes I and II, by Schwartz, Perry and Birch.

  The total amount of surfactant advantageously represents from 5 to 40% of the weight of the composition. The adjuvant can include mineral and / or organic adjuvants. Suitable builders include sodium carbonate, aluminosilicates, preferably zeolites, e.g. ZEOLITE A24, phosphates and polymeric builders, e.g. polycarboxylates and acrylic acid / maleic acid copolymers. The adjuvant can comprise a silicate, preferably a crystalline lamellar silicate and, optionally, a zeolite and / or a salt, for example a citrate. The adjuvant is advantageously present in a proportion of 10 to 80% and, preferably, from 15 to

%, of the weight of the composition.

  The composition may include a bleaching system which may be based on oxygen or chlorine. Peroxide bleaching compounds, for example mineral persalts and organic peracids, are preferred. Percarbonate is particularly preferred. The bleaching agent is advantageously present at 5 to 35%

  by weight and preferably from 10 to 25%.

  A bleach activator may also be present,

  for example tetraacetylethylene diamine (TAED), before-

  suitably at a rate of 1 to 8% by weight of the composition.

  Other conventional constituents may be present in the composition, in particular a silicate, a fluorescent agent, a carbonate, a sulfate, a powder structuring enzyme, a perfume, dyes, as the case may be.

  if necessary. This list is by no means exhaustive.

  The invention is illustrated by the examples not

following limitations.

Example 1

  A composition according to the present invention is produced having the constituents listed below, by mixing the constituents in a Lodige CB30 recycler mixer to obtain composition particles, and then a densification and agglomeration of the particles is carried out, to produce a powder. having an average particle size in the range of 550 to 700 µm, a particle porosity of less than 10% and an apparent density exceeding 750 g / 1. Several components, including a percarbonate bleach, a bleach activator, sodium silicate, sodium carbonate, an enzymatic fluorescent agent and a perfume, are added after the fact to the powder, to produce a fully formulated powder comprising about 60 % of the densified powder and around 40%

of products added afterwards.

  The densified powder consists of the following substances: Parts by weight Anionic surfactant (Na-PAS) 10 Non-ionic surfactant 22 Soap 3 Zeolite A24 55 Sodium carbonate 2 The densified powder is sieved and the proportion of particles having a particle size less than 180 μm East

less than 5%.

  Comparative Examples Comparative compositions are produced having the same composition as in Example 1, but the proportion of densified powder particles having a particle size less than 180 μm is greater than 10%, to be more

accurate is 20%, 30% and 40%.

Example 2

  The distribution properties of the compositions produced in Example 1 and in the comparative example are studied, by placing 100 g of the composition in a PHILIPS AWB 126/127 dispenser and passing water through the dispenser to a flow rate of 5 1 / minute for one minute, under a pressure of 0.5 atm, and by measuring the amount of residue remaining in the dispenser as a percentage of the total composition. The experiences are

  made with water at a temperature of 10 C and 20 C.

  The results are indicated in the form of a graph in the appended FIG. 1, which shows that the compositions having a low proportion of fine materials offer excellent distribution properties and, in particular, that the compositions having a proportion of fines do not

  not more than 5% have no significant difference

  distribution properties at 10 ° C and 20 C.

Claims (10)

R E V E N D I C A T IONS   1. Particulate detergent composition, comprising a surfactant and an adjuvant and having a particle porosity not exceeding 10% of the pore volume, characterized in that the particle size distribution of the particles is such that not more than 10% of the particles   have a particle size not exceeding 180 µm.   2. Composition according to claim 1, characterized in that not more than 5% of the particles have a   particle size not exceeding 180 µm.   3. Composition according to claim 2, characterized in that it has a particle porosity of 3 to 8% of the pore volume.   4. Composition according to any one of the claims   previous, characterized in that not more than 10% of   particles have a particle size exceeding 1,400 µm.   5. Composition according to any one of the claims   above, characterized in that it leaves a residue of less than 10% of the composition when it is dispensed from a PHILIPS AWB 126/127 dispenser at a water temperature of 20 C and at a flow rate d 5 liters of water per minute for 1 minute.   6. Composition according to any one of the claims   above, characterized in that it comprises an anionic surfactant, a nonionic surfactant and an adjuvant, which preferably comprises a silicate and a zeolite. 7. Detergent product comprising a detergent composition   as defined in any one of the claims   above, characterized in that it also comprises an additional compound, preferably a bleaching agent   percarbonate, mixed with it.   8. Process for preparing a detergent composition having an apparent density exceeding 750 g / l, characterized in that it consists in mixing the constituents of the composition to form particles and in densifying the particles so that the particles have a porosity not exceeding 10% of the pore volume and to classify the particles so that not more than 10% of the particles have a particle size not exceeding pm. 9. Method according to claim 8, characterized in that some of the constituents of the composition are mixed in a high shear step, at a mixing speed of 100 to 2,500 holes / min, then cooled and / or dried. 10. Method according to claim 9, characterized in that the constituents of the compositions are mixed in a moderate shearing step, at a mixing speed of 40 to 160 revolutions / min, before or immediately after the high shearing step.