ES2222583T3 - DETERGENT COMPOSITIONS. - Google Patents

Abstract

Detergent compositions are presented in the form of tablets for washing fabrics containing at least 30% but preferably or more than 56% of particles containing most or all non-soap surfactants so that this supplies between 20 and 3l 50% of these particles, which also contain an adjuvant for water soluble detergents. The non-soap surfactant is a mixture of anionic and non-ionic surfactants wherein the amount of anionic surfactant is at least 1.5 times the amount of the non-ionic surfactant. These particles are accompanied by at least 15% of material that is different from the soapy or organic surfactant and that promotes rapid dissolution and disintegration of the tablet composition. The preferred material is sodium tripolyphosphate which contains a majority of phase anhydride form ((I) and is partially hydrated so that it contains between 1 and 4% of its hydration water weight. The particles form a network which confers both strength and elasticity to the tablet before use, while the water-soluble material that accompanies the particles promotes rapid dissolution and disintegration at the time of use, thus obtaining an improved combination of resistance when manipulates, resistance to breakage in transport and speed of disintegration.

Description

Detergent compositions.

This invention relates to compositions detergents in the form of pills to use in washing tissues.

Detergent compositions are described in form of tablet, for example, in GB 911204 (Unilever) documents, US 3953350 (Kao), JP 60-015500A (Lion) and EP-A-711827 (Unilever); and they are sold commercially in Spain. The pills have several advantages over other powdered products: they do not require measurement and, therefore, They are easier to handle and supply in the wash load and are  more compact, thus facilitating more economical storage.

Such detergent tablets are prepared generally compressing or compacting an amount of composition particulate detergent. It is desirable that the pills have adequate mechanical strength when dry, before to use, even if they disintegrate and disperse / dissolve quickly when added to the wash water. It has been tested It is not simple to get both properties simultaneously. TO As more pressure is used when compacting a tablet, they also increase the density and strength of the tablet, but the disintegration / dissolution rate when the tablet enters Contact with wash water decreases.

During the period from about 1960 to 1970 there was considerable research activity in relation to the tablets for use in tissue washing. Was published a large number of patents by leading manufacturers of detergents Detergent tablets sold commercially in the United States of America and some European countries.

However, the pills disappeared from the markets in almost all countries (Spain is the apparent exception) even though the pills have obvious advantages and have become known as a product form for compositions of dishwashers, which are characterized by a low content of organic surfactant

The document US-A-3018267 (Procter & Gamble) shows that the force should be limited, and therefore the pressure, applied when a tablet composition is compacted, or else the pills would take too long to dissolve.

The compression pressures used in the Examples of this document were approximately 1.2 to 2.1 MPa. In another part of the document it is proposed that the pressure should not exceed approximately 2.5 MPa to avoid disintegration Slow found with higher pressures.

A number of proposals have been suggested as a form to improve the compromise between the opposite desired objectives, but the desire to improve the resistance of the pills still continues no loss of speed of disintegration, and vice versa.

Some documents have proposed treatments or surface coatings to increase the strength of the tablet. For example, the document US-A-3451928 (Colgate) states that the problem of resistance against dissolution rate remains unresolved, and proposes a spray treatment of water, followed by rapid heating. The document US-A-3324038 (Procter) proposes the application of a coating containing urea.

It is known how to include materials whose function is increase the disintegration of the pills when placed in the wash water Some pills, which are sold commercially, They incorporate urea for this purpose. Urea has a very soluble solubility. high in water, exceeding 100 g per 100 ml of water at 20 ° C. He EP-A-711827 teaches the use of sodium citrate for the same purpose.

Detergent compositions, including tablet compositions often contain a mixture of organic anionic and nonionic surfactants. Often is desirable to include both types of surfactant, for the benefits of the composition when washing fabrics.

It has been found now that you can achieve a improved compromise between the strength of the pads and the speed of disintegration following certain related principles with the formulation and manufacture of the pills.

At the same time it is possible to incorporate materials which is desired to give a good performance in washing, and it is possible to formulate ingredients components of the tablet so that they are satisfactory in handling during Pill manufacturing.

Also, it has been found that two are relevant different measures of the strength of the tablet for properties observed by a consumer. The force to provoke the fracture is a direct determination of resistance, and indicates the resistance of the tablet to breakage when handled by a consumer at the time of use. The amount of energy (or mechanical work) used before the fracture is a measure of the deformability of the tablet and is relevant to the resistance of the tablet to break during transport.

Both properties are relevant to the perception of pills by the consumer: consumers will want the pills to be enough resistant to handling, so that they arrive intact, and that disintegrate quickly and completely at the time of use. Following these principles of the invention as regards the formulation, it is possible to achieve a good combination of these properties.

In this invention, it has been found desirable incorporate most (if not all) of the surfactants in particles that constitute a substantial part but, of no mode, the whole composition of a pill. Organic surfactant in these particles provides a substantial part of the weight, but in any way, all its weight.

Second, it is desirable that the surfactant be a mixture of anionic and non-ionic detergent surfactants non-soapy (preferably accompanied by soap) in which both are present in significant quantities, but the Anionic is majority.

Third, the balance of the composition must then contain material, other than the surfactant organic, that is soluble in water. This formulation approach is Applies to the composition of a pill as a whole.

So, according to a first aspect of this invention, a detergent tablet of a compressed particulate composition, in which the tablet comprises an organic surfactant and detergency builder soluble in water, characterized in that the tablet contains 30 to 65% by weight (of the tablet) of particles containing 25 to 80% by weight (of these particles) of detergency adjuvant soluble in water and 20 to 50% by weight (of these particles) of a non-soap organic surfactant which is an anionic surfactant and non-ionic in a ratio of 5: 1 to 1.5: 1, and because, in addition to said particles, the tablet contains at least 15% by weight (of the tablet) of a substance that is different from a soap or organic surfactant, and having a water solubility of at minus 10 g / liter at 20 ° C.

It is believed that it is beneficial to concentrate the majority or all the surfactant in particles rich in surfactant, and use a substantial proportion of anionic surfactant, to provide pills that have as much resistance as elasticity, while allowing the rest of the composition of the tablet contains a substantial proportion of soluble material in water, which helps the disintegration of the pills at the moment of use

It is not necessary to include surfactant as adjuvant material in the part of the composition outside the particles rich in surfactant. It is advantageous to exclude it from this part of the composition, to avoid interference with the prompt dissolution of this part of the composition.

Thus, it is preferred that the weight of the surfactant non-soap anionic in the particles is at least 1.7 times the weight of the nonionic surfactant in them. More preferably, this weight ratio of anionic surfactant to nonionic surfactant is in a range of 2: 1 to 5: 1, and more preferably 2: 1 to 4: 1. Preferably, these particles contain at least 80% in weight, better at least 90% or even 95%, of the entire surfactant Organic (including any soap) in the tablet.

The water soluble material that is present in the composition, externally to particles rich in surfactant, preferably comprises 15 to 40% (better 16 or even 25% to 35%) by weight (of the tablet) of one or more materials selected from:

compounds with a water solubility that exceeds 50 grams per 100 grams of water;

sodium tripolyphosphate containing the minus 50% of its own weight of the anhydrous form of phase I, and preferably partially hydrated so that it contains water of hydration in an amount that is at least 1% by weight of the sodium tripolyphosphate;

mixtures thereof.

It is greatly preferred that the soluble material in water that is present in the composition, externally at particles rich in surfactant, be present as particles that they are substantially free of surfactant, that is, they do not contain more than 5% of its own weight of organic surfactant.

A preferred form of this invention provides a detergent tablet of compressed particulate composition which contains

(i)

from 35 to 60% by weight (and probably 41 to 53, 56 or 60% by weight) of particles containing non-soap anionic surfactant, nonionic surfactant and detergency adjuvant soluble in Water,

(ii)

from 15 to 40% by weight (and probably 16 or 17 to 35% by weight) of particles that are substantially free of surfactant, is say they contain at least 95% of their own weight of soluble material in water but do not contain more than 5% of their own weight of organic surfactant, and

(iii)

from 0 to 50% by weight of additional particulate ingredients,

wherein said first particles (i) contain at least 20% preferably at least 24% of their own non-soap surfactant weight and the anionic surfactant weight in them it is 1.5 to 5 times the weight of the nonionic surfactant in they.

In another aspect, this invention provides a detergent tablet of compressed particulate composition in the that the tablet comprises particles containing surfactant non-soapy anionic, non-ionic surfactant, preferably soap and other water soluble ingredients, characterized in that the particles contain at least 20% by weight in total of the anionic and non-ionic surfactants, and because a test pill consisting of said non-soap anionic surfactant, surfactant non-ionic, and any soap in the same proportions, along with 15% by weight of moisture, it has a breaking resistance as defines here of at least 0.04 MPa and a module as defined here of no more than 10 MPa, preferably no more than 8 MPa.

In yet another additional aspect, this invention provides the use of particles containing a mixture of non-soap anionic and non-ionic surfactants and adjuvant of detergency, in which the concentration by weight of surfactant non-soapy anionic is at least 1.5 times as large as the concentration by weight of non-ionic surfactant, and concentration Total of these surfactants is at least 20% by weight of the particles to provide resistance improvements and elasticity of the pads versus the speed of disintegration

The tablet of the invention is homogeneous. In the This descriptive report the term "homogeneous" is used to mean a tablet produced by compacting a only particle composition, but does not imply that all particles of that composition are necessarily of composition identical The term "heterogeneous" is used to mean a tablet consisting of a plurality of discrete regions, by example layers, inserts or coatings, each derived by compaction of a particle composition.

Drawings

The accompanying drawings illustrate in the form of Diagram the test of a cylindrical tablet:

Figure 1a shows a pill when it enters for the first time in contact with the dishes of a test machine of materials,

Figure 1b shows the tablet at the point of fracture,

Figure 2 diagrammatically illustrates the shape of a graph obtained during the test.

Pill Assay

The disintegration rate of the tablets by means of a test procedure in which placed a pill on a plastic sieve with a size of 2 mm mesh that is submerged in 9 liters of water demineralized at room temperature of 20 ° C. The conductivity of Water is followed until it reached a constant value. He drink the time for dissolution of the pills as the time (T_ {90}) so that the change in water conductivity reaches 90% of its final magnitude.

The resistance of the tablet has been tested by a procedure illustrated by the drawings that accompany in which a tablet 10 is radially compressed cylindrical between the plates 12, 14 of a test machine of materials up to the fractures of the tablet. In the position of heading shown in figure 1a, plates 12, 14 are in contact with the tablet, but do not apply force. The force is apply, as indicated by arrows 16 to compress the tablet. The test machine measures the applied force (F), and also the displacement (x) of the plates with each other as they compress the pill. Also known is the distance (and) between the dishes before the force is applied, which is the diameter of The pill. In the fracture, illustrated in Figure 1b, the tablet it cracks (for example, as shown in 18), and the force drops applied necessary to maintain displacement. The measure is makes discontinuous when the force applied necessary to maintain the displacement has fallen by 25% with respect to its maximum value (indicated as point D in figure 2 below).

A graph of the force (F) versus displacement (x) has the form illustrated by figure 2. The maximum force is the force in the fracture (F_ {f}). From this force measurement can be calculated a test parameter, which It has been used in the past, called fracture effort diametral, using the equation

\ sigma = \ frac {2F_ {f}} {\ pi Dt}

in which \ sigma is the effort to Diametral fracture in Pascals, F_ {f} is the force applied in Newtons to cause fracture, D is the diameter of the tablet in meters, and t is the thickness of the tablet in meters

The fracture force divided by the area of a diametral plane through the tablet (approximately the area of crack 18) is the breaking strength, with units of Pascals

The breaking energy is the area under the graph of force against displacement, to the point of breaking off. It is shown shaded in Figure 2, and is given by equation:

E_ {b} = \ int ^ {x_ {f}} {0} F (x) dx

in which E_ {b} is the energy of break in joules,

x is the displacement in meters,

F is the force applied in Newtons in the displacement x, y

x_ {f} is the displacement in the fracture.

The displacement in the fracture in relation to pickup diameter is relative displacement x_ {f} / y.

The breaking resistance divided by the relative displacement is a module, whose value is inverse to the elasticity of the tablet.

Materials and other features

The materials that can be used in the pills of this invention will now be discussed with more detail.

Anionic surfactant compounds

Synthetic anionic surfactants (i.e. not soapy) are well known to those experts in the technique. The anionic surfactant may comprise, total or predominantly linear alkylbenzenesulfonate of the formula

one

where R is a linear alkyl of 8 to 15 carbon atoms, and M + is a solubilizing cation, especially sodium.

The primary alkyl sulfate, which has the formula

ROSO_3 <+> - M +

in which R is an alkyl chain or alkenyl of 8 to 18 carbon atoms, especially 10 to 14 carbon atoms, and M + is a solubilizing cation, it is also commercially significant as an anionic surfactant and can be used in this invention.

Frequently, such linear alkylbenzenesulfonate or primary alkyl sulfate of the above formula, or a mixture of they will be the desired non-soap anionic surfactant, and can provide 75 to 100% of any non-anionic surfactant Soapy in the composition.

Examples of other non-anionic surfactants Soaps include olefinsulfonates; alkanesulfonates; dialkylsulfosuccinates; and acid ester sulfonates fatty

One or more soaps may also be included. fatty acids, in addition to the non-soap anionic surfactant required. Examples of sodium soaps obtained from fatty acids from coconut oil, beef tallow, sunflower oil or of hardened rapeseed. These can be formed by adding fatty acid and a base such as sodium carbonate to a suspension which is spray dried to form rich base particles in surfactant.

Nonionic surfactant compounds

Nonionic surfactant compounds include in particular the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides or alkylphenols, with oxides of alkylene, especially ethylene oxide.

Nonionic surfactant compounds specific are condensed from (C 8-22) alkyl - phenols With ethylene oxide, alcohol condensation products C 8-20 primary or secondary aliphatics linear or branched with ethylene oxide, and products obtained by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine.

The ethoxylates of primary alcohols and Secondary ones are especially preferred, especially ethoxylates of primary and secondary alcohols C_ {9-11} and C_ {15-15} with a average of 3 to 20 moles of ethylene oxide per mole of alcohol.

Detergency adjuvant

The composition that compacts to form tablets include water soluble detergency adjuvant.

Inorganic detergency builders Water soluble phosphorus-containing include orthophosphates, metaphosphates, pyrophosphates and alkali metal polyphosphates. Specific examples of inorganic phosphate builders include sodium tripolyphosphates, orthophosphates and hexametaphosphates and potassium.

Non-phosphorous water soluble adjuvants They can be organic and inorganic. The inorganic adjuvants that may be present include alkali metal carbonate (usually sodium); while organic adjuvants include polycarboxylate polymers, such as polyacrylates and acrylic / maleic copolymers, monomeric polycarboxylates such as citrates, gluconates, oxidisuccinates, mono-, di- and glycerol trisuccinates, carboxymethyloxysuccinates, carboxymethylximalonates, dipicolinates and hydroxyethyliminodiacetates.

Pill compositions include preferably polycarboxylate polymers, more especially Acrylic / maleic polyacrylates and copolymers that can work as adjuvants and also inhibit unwanted deposition on washing liquid tissues.

Proportions

Generally, a pill according to this The invention will generally contain 2 or 5% by weight up to 40 or 50% in non-soapy surfactant weight, and 5 or 10% by weight up to 60 u 80% by weight of detergency adjuvant.

The concentration of anionic surfactant does not soapy in the pill will usually be at least once and a half the concentration of nonionic surfactant. It is preferably from 3% by weight up to, for example 30 or 40% by weight of the tablet, per example of 3% by weight up to 30 or 40% by weight. The concentration of nonionic surfactant is preferably at least 2% by weight of the tablet, such as 2 to 15% by weight of the tablet.

The amount of soap in the tablet is preferably from 0.1 or 0.2 to 1% or 2% by weight of the tablet. Higher proportions such as up to 4% are less preferred.

In accordance with this invention, the surfactant non-soap anionic, non-ionic surfactant, adjuvant of water soluble detergent and other materials that include preferably soap, they are formed into particles so that the non-soap surfactant provides 20 to 50% of the weight of these particles Preferably, the non-soap surfactant provides at least 22% or 24% of the weight of these particles, and more preferably at least 28%, desirably up to 45% of its weight. When soap is present, it is desirably from 0.2 to 2%, and possibly more, up to 3% or 4% by weight of these particles, and in these particles the weight ratio of nonionic detergent to Soap is preferably 5: 1, better 10: 1, at 30: 1.

Such particles can be obtained by drying by spraying or by a granulation process. Preferably contain water soluble detergency adjuvant in a amount that is 30 to 80% of the weight of these particles, better 30 or 40 to 60% of the weight of these particles.

The mixture of surfactants used in these particles can be tested directly mechanically analogous to the tablet test, discussed above. For this is obtained on a small scale a mixture of the surfactants not soaps and any soap, and is molded cylindrically or in some other way in which a cylinder can be cut. Yes it is necessary it dries to reduce the water content up to 15% by weight (approximately up to 5% moisture in the particles that contain this mixture of surfactants). Then, it is tested in a material testing machine in the manner described previously for the test of the pills. This procedure Mechanical test can also be applied to the pads obtained only from the particles rich in surfactant.

The effect of the surfactant has been found anionic in these particles is to increase elasticity without affecting much the magnitude of the force to cause the fracture. He Nonionic surfactant tends to have some opposite effect. He Soap, when present, cooperates with the non-ionic surfactant in reducing the mobility of the nonionic surfactant and increasing the pad resistance (measured by force to cause fracture).

Using sufficient amounts of surfactant non-soapy anionic, non-ionic surfactant and preferably soap, it has been found that resistance is possible and adequate elasticity of a test tablet, which in turn means that the same mixture will give pills with good resistance and elasticity.

Breaking strength is desirably at minus 0.04 MPa, preferably at least 0.05 MPa. The module is desirably not greater than 10 MPa preferably not greater than 8 or even 5 MPa.

It has been observed that a mixture of alkylbenzenesulfonate and non-ionic surfactant, in a ratio 1.16: 1, gave a module of about 15 MPa; but when ratios were changed to 2.2: 1 (according to this invention) the  module dropped dramatically to around 4.0 to 4.5 MPa, which indicates greater elasticity, with a very small change in fracture strength

Particles that promote disintegration

In addition to the required particles they contain surfactants and an adjuvant, a tablet of this invention it contains water soluble material that serves to promote the disintegration Preferably this is provided as particles. which are substantially free of organic surfactant.

A preferred possibility is that said particles that promote disintegration are particles that contain sodium tripolyphosphate with more than 50% of it (by weight of the particles) in the form of anhydrous phase I.

Sodium tripolyphosphate is very well known as a sequestering adjuvant in detergent compositions. It exists in a hydrated form and two anhydrous crystalline forms. These are the normal crystalline anhydrous form, known as phase II which is the form at low temperature, and phase I which is stable at high temperature. The conversion from phase II to phase I takes place a lot quickly when heating above the transition temperature, which is around 420 ° C, but the reverse reaction is slow. In consequently, phase I sodium tripolyphosphate is metastable at room temperature.

In the document US-A-4536377 a procedure is given for the manufacture of particles containing a high proportion of the phase I form of sodium tripolyphosphate by spray drying below 420 °.

Particles containing this form of phase I they often contain the phase I form of sodium tripolyphosphate as at least 55% by weight of the tripolyphosphate in the particles. Other forms of sodium tripolyphosphate will be present. Normally to a lesser degree. Other salts may be included in the particles, although that is not preferred. An additional preference is that sodium tripolyphosphate is partially hydrated. He degree of hydration should be at least 1% by weight of the sodium tripolyphosphate in the particles. Can be in a 2.5 to 4% range, or it may be longer.

The right material is commercially available. Suppliers include Rhone-Poulenc, France, and Albright & Wilson, United Kingdom.

The "Rhodiaphos HPA 3.5" of Rhone-Poulenc has been found particularly suitable. It is a characteristic of this grade of tripolyphosphate that it hydrates very quickly in a standard Olten test. It has been found that it hydrates as quickly as a tripolyphosphate of anhydrous sodium, although prehydration seems to be beneficial for avoid unwanted crystallization of hexahydrate when the material comes into contact with water at the time of utilization.

Another possibility that can be used instead of tripolyphosphate, or in a mixture with it, is that these particles that promote disintegration contain at least 50% of their own weight, better at least 80%, of a material that has a solubility in deionized water at 20 ° C of at least 50 grams per 100 grams of Water.

The mentioned particles can provide material of such solubility in an amount that is at least 7% in weight or 12% by weight of the overall composition of the tablet.

A solubility of at least 50 grams per 100 grams of water at 20 ° C is an exceptionally high solubility: many materials that are classified as water soluble are less soluble than this.

Listed below are some materials highly soluble in water that can be used, with their solubilities expressed as grams of solid to form a saturated solution in 100 grams of water at 20 ° C:

Material Solubility in water (g / 100 g) Sodium citrate dihydrate 72 Carbonate potassium 112 Urea > 100 Acetate of sodium 119 Sodium acetate trihydrate 76 Magnesium sulphate 7H 2 O 71 Acetate potassium > 200

On the contrary, the solubilities of some Other usual materials at 20ºC are:

Material Solubility in water (g / 100 g) Chloride sodium 36 Sodium sulfate decahydrate 21.5 Sodium carbonate anhydrous 8.0 Sodium percarbonate anhydrous 12 Sodium perborate anhydrous 3.7 Sodium tripolyphosphate anhydrous fifteen

Preferably, this highly soluble material in water it is incorporated as particles of the material in a form substantially pure (ie, each such particle it contains about 95% by weight of the material). However, the mentioned particles may contain material of such solubility in a mixture with another material, with the condition that the material of the specified solubility provide at least 50% in weight of these particles.

Other ingredients

Detergent tablets according to the invention may contain a bleaching system. This includes preferably one or more peroxy bleaching compounds, for for example, inorganic persalts or organic peroxyacids, which can be used in conjunction with activators to improve the action bleach at low wash temperatures. If there is any compound Worried present, the amount is likely to be in a range of 10 to 25% by weight of the tablet.

Preferred inorganic persalts are perborate of sodium monohydrate and tetrahydrate, and sodium percarbonate. Bleach activators have been described extensively in the technique. Preferred examples include acid precursors peracetic, for example, tetraacetylethylenediamine (TAED) and perbenzoic acid precursors. Also of interest are quaternary ammonium and phosphonium bleaching activators, disclosed in documents US 4751015 and US 4818426 (Lever Brothers Company). Another type of bleach activator that can be use, but that is not a bleaching precursor, it is a catalyst Transition metal as disclosed in the documents EP-A-458397, EP-A-458398 and EP-A-549272. A bleaching system may also include a bleach stabilizer (sequestrant heavy metals), such as ethylenediamine tetramethylene phosphonate and diethylenetriamin-pentamethylene phosphonate.

The bleach activator is present usually in an amount of 1 to 10% by weight of the tablet, possibly less in the case of a metal catalyst than transition that can be used as 0.1% or more by weight of the tablet.

The detergent tablets of the invention also they may contain one of the well-known detergency enzymes in the technique for its ability to degrade various soils and stains and thus help their removal. The right enzymes include various proteases, cellulases, lipases, amylases, and their mixtures, which are designed to remove a variety of dirt and tissue stains. Detergency enzymes are used usually in the form of granules or marumes, optionally with a protective coating, in an amount of about 0.1% at around 3.0% by weight of the tablet.

The detergent tablets of the invention can also contain a fluorescent agent (optical brightener), by example, Tinopal DMS (registered trademark) or Tinopal CBS, available from Ciba-Geigy AG, Basel, Switzerland. Tinopal DMS is 4,4'-bis- (2-morpholino-4-anilino-s-triazin-6-ylamino) stilbendisulfonate of disodium; and Tinopal CBS is 2,2'-bis- (phenylstyryl) disulfonate of disodium

Advantageously a material is included antifoam, especially if the detergent tablet is intended primarily for use in automatic washing machines of the type of front loading drum. Antifoam materials in form Granular are described in EP 266863A (Unilever). Such antifoam granules typically comprise an oil mixture silicone, petroleum jelly, hydrophobic silica and alkyl phosphate as an antifoam active material, absorbed on a material inorganic support based on water soluble carbonate absorbed porous.

It may also be desirable for a pill detergent of the invention include an amount of a silicate of alkali metal, particularly ortho-, meta- or sodium disilicate. The presence of such alkali metal silicates can be advantageous to provide corrosion protection of parts metallic in the washing machines, in addition to providing certain adjuvance of detergency. Preferably the rich particles in surfactant they contain 5 to 15% silicate by weight of these particles This improves the resistance and free flow of these particles before the formation of pills.

Additional ingredients that can be used in The detergent tablet of the invention for washing fabrics includes anti-redeposition agents such as sodium carboxymethyl cellulose, linear chain polyvinylpyrrolidone, and cellulose ethers such as methylcellulose and ethylhydroxyethylcellulose; agents fabric softeners; heavy metal hijackers, such as EDTA; perfumes; and colored dyes or specks.

These other various ingredients may be present in the particles rich in surfactants or in the rest of the composition externally to them. It is preferred that any bleaching agent is contained in the rest of the composition externally to particles rich in surfactants.

Particle size and distribution

A detergent tablet of this invention is a matrix of compacted particles.

Preferably the particulate composition it has an average particle size before compaction in the range of 200 to 2000 µm, more preferably 250 to 1400 \ mum. Fine particles, smaller than 180 µm or 200 um, can be removed by screening before the formation of the tablet, if desired, although it has been observed that this is not always  essential.

Although the starting particle composition it can have, in principle, any apparent density, the present invention is especially applicable to pills obtained compacting powders of relatively high bulk density due to its greater tendency to exhibit problems of disintegration and dispersion.  Such tablets have the advantage that, compared with a tablet obtained from a powder of low apparent density, one dose given detergent composition can be presented as a pill smaller.

Thus, the particulate composition of heading can adequately have an apparent density of at least 400 g / liter and perhaps at least 600 g / liter.

The granular detergent compositions of high apparent density, prepared by granulation and densification in a high speed mixer / granulator, such as It is described and claimed in EP 340013A (Unilever), EP 352135A (Unilever) and EP 425277A (Unilever), or by means of continuous granulation / densification processes described and claimed in EP 367339A (Unilever) and EP 390251A (Unilever), are inherently suitable for use herein. invention.

Tablet formation

The formation of pills supposes the compaction of the particulate composition. It is known and you can use a variety of pill forming machinery. Usually, it will work by stamping an amount of the particulate composition which is confined in a matrix.

The formation of pills can be carried out no heat application, to take place at temperature ambient or at a temperature above room temperature. In order to carry out the formation of tablets at a temperature which is higher than room temperature, the composition in particles are preferably supplied to the forming machinery of pills at an elevated temperature. Of course this will supply heat to the tablet-forming machinery, but the Machinery can also be heated in some other way.

If any heat is supplied, it is contemplated that it will be supplied conventionally, such as by passing the particulate composition through an oven, instead of through any microwave energy application.

The size of the tablet will oscillate properly 10 to 160 g, preferably 15 to 60 g, depending on the conditions of the intended use, and if it represents a dose for a medium load in washing fabrics or a dishwasher or a fractional part of such a dose. The pills may have any way. However, for ease of packaging preferably they are substantially cross-sectional blocks uniform, such as cylinders or cuboids. The overall density of a tablet is preferably in a range of 1040 or 1050 g / liter up to 1300 g / liter. The density of the tablet may be quite well in an interval of up to no more than 1250 or even 1200 g / liter

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Examples

Pills were obtained for use in the tissue washing, starting from dried base powders spraying of the following compositions:

2

* Added to the suspension as anhydrous sodium tripolyphosphate containing minus 70% of the way phase II.

This powder was mixed with other ingredients to form particulate compositions as tabulated below. These include specified sodium tripolyphosphate particles to contain 70% of the phase I form and contain 3.5% of water from hydration (Rhodia-Phos HPA 3.5 available from Rhone-Poulenc).

The compositions contained the following weight percentages:

3

40 g portions of each were formed composition in cylindrical pads 44 mm in diameter, using a Carver manual press, with sufficient pressure applied to produce pills that dissolved up to 90% of the complete dissolution in approximately equal times not exceeded four minutes, in water at 20C. The forces applied in an interval of 2 to 4 kN proved to be normally sufficient when this manual press was used.

To test the dissolution of the tablets, used a test procedure in which a pill was placed on a plastic sieve with a mesh size of 2 mm that is submerged in 9 liters of demineralized water at temperature 20ºC environment. The conductivity of the water was followed until reached a constant value. He took the time to dissolve the pills as time (T_ {90}) for the change in Water conductivity reached 90% of its final magnitude.

The resistance of these pills was measured compressing them radially, between the plates of a machine universal material testing until the fracture of the tablet.

The fracture strength was calculated and measured. also the displacement in the fracture. Breaking energy, explained above, is the area under the force graph facing displacement until fracture.

The following table gives the results obtained for the tablets of examples 2 and 3 incorporating the invention and the comparative tablets of example 1. It is evident that the pills incorporating the invention were stronger although they dissolved in a similar way. The mechanical properties of The surfactant mixture used is included in the table.

4

Claims (15)

1. A detergent tablet of a compressed particle composition, in which the tablet is homogeneous and comprises organic surfactant and adjuvant to water-soluble detergency, characterized in that the tablet contains 30 to 65% by weight of particles containing 25 at 80% by weight (of these particles) of adjuvant of the water-soluble detergency and from 20 to 50% by weight (of these particles) of non-soapy organic surfactant which is an anionic and non-ionic surfactant in a weight ratio of 5: 1 to 1.5: 1, and because, in addition to said particles, the tablet contains at least 15% or more by weight (of the tablet) of material that is different from an organic soap or surfactant, and that has a water solubility of at least 10 g / liter at 20 ° C. 2. A tablet according to claim 1, in the tablet contains the mentioned particles in an amount of 41 at 56% by weight. 3. A tablet according to claim 1 or claim 2, wherein the weight ratio of surfactants anionic to nonionic surfactant is in a range of 1.7: 1 to 5: 1. 4. One tablet according to any of the claims 1 to 3, wherein the weight ratio of nonionic soap surfactant in said particles is in a range from 10: 1 to 30: 1. 5. A tablet according to any one of the claims 1 to 4, wherein the amount of surfactant non-soap organic in the said particles is 22 to 45% in particle weight 6. A tablet according to any one of the claims 1 to 5, containing soap in said particles in an amount of 0.2 to 2% by weight of the particles. 7. A tablet according to any one of the claims 1 to 6, wherein said particles contain 30 to 80% by weight (of the particles) of adjuvant of the water soluble detergency which is an alkali metal salt of a condensed phosphate 8. A tablet according to claim 7, in the that the salt of a condensed phosphate is sodium tripolyphosphate. 9. A tablet according to any one of the claims 1 to 8, wherein the water soluble material present in addition to said particles comprises 15% or more (in pill weight) in the form of additional particles that contain no more than 5% of its own surfactant weight organic. 10. A tablet according to any one of the claims 1 to 9, wherein the water soluble substance present in addition to said particles comprises 25 to 35% (in tablet weight) of material with a water solubility of at minus 50 g / 100 g of water at 20 ° C, or sodium tripolyphosphate that it contains more than 50% of its own weight of the anhydrous form of the phase I, or a mixture thereof. 11. A tablet according to claim 10, in that the water soluble substance present in addition to those mentioned particles comprise 15 to 35% (by weight of the tablet) of sodium tripolyphosphate containing more than 50% of its own weight of the anhydrous form of phase I, which is partially hydrated from so that it contains 1 to 4% by weight of hydration water. 12. A tablet according to any one of the claims 1 to 11, wherein said anionic surfactant is mostly sodium alkylbenzenesulfonate, accompanied optionally for a smaller amount of other surfactant anionic 13. A tablet according to any one of the claims 1 to 12, wherein said nonionic surfactant is mostly ethoxylated fatty alcohol, optionally accompanied for a small amount of other non-ionic surfactant. 14. A detergent tablet according to any one of claims 1 to 13, which is a conformed by understanding of a single particle composition. 15. A procedure to prepare a pill detergent according to any one of claims 1 to 14, which understand mix a) 30 to 65% by weight of particles containing 25 to 80% by weight (of these particles) of adjuvant of the water soluble detergent and 20 to 50% by weight (of these particles) of a non-soap organic surfactant which is a anionic and non-ionic surfactant in a weight ratio of 5: 1 a 1.5: 1, with b) 15% or more by weight of material that is different to soap or an organic surfactant, and which has a solubility in water of at least 10 g / liter at 20 ° C, and compacting the mixture in a tablet.