Process for preparing granular detergent compositions

Description of the invention

The invention relates to a process for the preparation of a granular detergent product with good powder properties. More specifically, the invention relates to a method in which a liquid binder is brought into contact with a solid particulate material in a gas fluidization granulator under controlled conditions.

Background of the invention

In recent years, there has been a great deal of interest in the preparation of detergent products by mainly mixing methods without the use of spray drying. In this type of process, the various ingredients are dry blended and optionally granulated with a liquid binder. The liquid binders typically used in such granulation processes are anionic surfactants, acidic surfactant precursors, nonionic surfactants or mixtures thereof.

When substantially mechanical agitation is used in the granulation process, the granular detergent product produced has a high bulk density, typically greater than 700 or 800 g / l. However, if the granulation process involves gas fluidization mixing, products having an average bulk density, for example from 300 to 750 g / l, are produced.

Liquid binders are generally pumped into the mixer to be brought into contact with the solid particulate material. Thus, liquid binders must be sufficiently low in viscosity to be pumpable. It is also important that the liquid binder is properly adsorbed and absorbed by the particulate solid material and that the liquid binder does not "leak" from the granular product, especially during storage.

When the produced powders contain particulate ingredients with low liquid absorption capacity, the mixing process with liquid binders can have a detrimental effect on the required flowability, good granularity and low water content of the resulting powder. In the obtained product, soft granules are formed with poor powder properties resulting from low adhesion forces of the surface of wet particles, which results in a poor granulate structure. Hard lump build-up caused by rapid exothermic hydration and the formation of crystalline bridges can also be a problem.

State of the art

Such problems have been solved by the use of a structurant-containing liquid binder as described in WO 98/11198 (Unilever). This document discloses preparing a liquid binder with a structurant to be pumpable at the temperature at which the liquid binder is formed, and then mixing the liquid binder with the solid component at a lower temperature at which the structurant solidifies the mixture.

WO 98/58048 (Unilever) describes a granulation process in which a liquid binder is sprayed onto a fluidizing solid material in a gas fluidization granulator.

During the process, the temperature of the fluidizing gas, and preferably also the bed temperature, is lowered or elevated. However, WO 98/58048 lacks any correlation between the fluidizing gas temperature and / or the bed temperature and the nature of the liquid binder material sprayed onto the fluidizing particulate material.

We have surprisingly found that when a liquid binder is brought into contact with a solid particulate material in a fluidized bed granulation process, significantly improved powder properties are obtained if the temperature in the granulator is controlled according to the viscosity of the liquid binder. More specifically, we have found that powder flow and storage properties, in particular cohesiveness, are improved.

Brief Description of the Invention

The invention relates to a process for the preparation of a granular detergent product comprising contacting a particulate solid material with a sprayed liquid binder while fluidizing the solid in a gas fluidization granulator, characterized in that the temperature of the fluidizing gas is increased to plus / minus 25 ° C, more preferably plus / minus 15 ° C of the temperature at which the liquid binder has a viscosity of 1 Pa.s at 50 s^-1, and the temperature of the atomizing gas is also increased in the range of plus / minus 25 ° C, more preferably plus / minus 15 ° C relative to the temperature at which the liquid binder has a viscosity of 1 Pa.s at 50s.^-1, and the temperature of the fluidizing gas and also the atomizing gas is maintained at an elevated level for as long as the liquid binder is sprayed onto the fluidizing solid.

PL 192 102 B1

Preferably, the temperature of the fluidizing gas and also the atomizing gas is increased and maintained at a temperature at which the liquid binder has a viscosity of 1 Pa.s at 50 s.^-1.

Preferably, a liquid binder containing one or more anionic surfactants or an acid precursor thereof is used in the process of the invention, and more particularly, a liquid binder containing one or more non-ionic surfactants is used.

A liquid binder containing a structurant is also preferably used.

The process of the invention preferably employs a solid particulate material treated in one or more mixers and / or granulator prior to treatment in a gas fluidization granulator.

The "pumpable temperature" of the liquid binder is here defined as the temperature at which the liquid binder has a viscosity of 1 Pa s at 50 s.^-1.

Detailed Description of the Invention

In the context of the invention, the term "granular detergent product" includes granular, wholesome products intended for sale as well as granular ingredients or adjuncts (additives) intended for the production of wholesome products, e.g. other form mixed with further components or adjoints. Thus, a granular detergent product as defined herein may be free of detergent-active material such as surfactant and / or soap. As a minimum requirement, it should contain at least one material of the type of conventional granular detergent product ingredients such as surfactant (including soap), builder, bleach or bleach component, enzyme, enzyme stabilizer or enzyme stabilizer component, anti-redeposition, fluorescer or optical brightener, anti-corrosive, antifoam, fragrance or dye.

However, in a preferred embodiment of the invention the granular detergent products contain a detergent active material such as synthetic surfactant and / or soap in an amount of at least 5 wt%, preferably at least 10 wt% of the product.

The term "powder" as used herein refers to materials essentially consisting of the grains of the individual materials and mixtures of such grains. The term "granules" as used herein means small particles of agglomerated smaller particles, for example agglomerated powder particles. The final product produced by the process of the invention consists of, or contains a high percentage of granules. Additional granular and / or powdery materials can optionally be post-dosed to such a product.

The terms "granulating" and "granulating" as used herein refer to a process in which, inter alia, particles are agglomerated.

For the purposes of the invention, the flow of the granular product is defined by the dynamic flow rate (DFR) in ml / s, measured as follows. A cylindrical glass tube with an internal diameter of 35 mm and a length of 600 mm is placed vertically with respect to the longitudinal axis. The lower end of the pipe ends with a polyvinyl chloride cone with an internal angle of 15 ° and a lower discharge opening with a diameter of 22.5 mm. The first flux sensor is located 150 mm above the exit and the second flux sensor 250 mm above the first sensor.

To determine the dynamic flow rate, the exit orifice is temporarily closed, and the cylinder is filled with the granular detergent product to a point about 10 cm above the top sensor. The exit orifice is opened and the flow time t (seconds) for the powder to flow from the upper sensor to the lower sensor is electronically measured. The activities are repeated 2 or 3 times and the average time is determined. If V is the volume (ml) of tube between the upper and lower sensors then the DRF value is expressed as V / t.

The unconfined compressibility (UCT) test provides a measure of the cohesiveness or "stickiness" of a product and can provide an indication of storage properties, for example in silos. UCT can be measured for both fresh powders and aged powders, but the UCT value is particularly significant to indicate the likely storage behavior of a powder.

The essence of the test is to compress the granular detergent product into a compact and then measure the force needed to break the compact. This is done in a device that includes a cylinder 89 mm in diameter and 114 mm in height (3.5 x 4.5 inches), a spindle and plastic disks and weights of a predetermined weight.

The cylinder, placed around the permanently fixed and clamped disc, is filled with the granular detergent product and the surface is leveled by dragging4

Follow it with a blade. A 50 g plastic disc is placed on top of the granular product, the spindle is lowered, and a 10 kg weight is slowly placed on top of the spindle disc. The weight is left in this position for 2 minutes, then the 10 kg weight is removed and the plunger is raised. The clamp is removed from the cylinder and the compact of granular product is ejected. If the compact is unbroken, a 50 gram plastic disc is placed on top and allowed to sit for approximately ten seconds. If the compact is not yet broken, a 100 gram disc is placed on top of the plastic discs and left for ten seconds. If the part is not yet broken, the pin is very gently lowered onto the discs and 250 g weights are added for ten-second intervals until the part breaks. When broken, the total weight of the mandrel, plastic disks and weights is recorded.

Powder cohesiveness is determined by the weight required to break the compact. The greater the weight required, the greater the UCT value and the more cohesive ("sticky") the powder is.

"Finished" as used herein is defined as particles having a diameter less than 180 micrometers.

"Coarse" material in the invention is defined as particles having a diameter greater than 1400 micrometers.

The amounts of fines and coarse material can be measured by sieve analysis.

Unless otherwise stated, values ​​for powder properties such as bulk density, DFR, moisture content etc. are for an aged granular detergent product.

Way

The process according to the invention is carried out in a gas fluidization granulator. A gas fluidization granulator is sometimes called a "fluid bed" granulator or mixer. This is not a strict term as such mixers can operate at such a high gas flow rate that a classic "bubbling" fluidized bed is not formed.

The gas fluidization granulator and agglomerating step are preferably carried out essentially as described in WO 98/58046 and WO 98/58047 (Unilever).

The gas fluidization device mainly consists of a chamber in which a stream of gas (hereinafter referred to as fluidizing gas), typically air, is used to induce a turbulent flow of the particulate solid to form a "cloud" of solid, and the liquid binder is sprayed onto or into cloud to bring about contact with single particles. As the process progresses, individual particles of the solid starting material agglomerate with the liquid binder to form granules.

A gas fluidization granulator typically operates at leading gas velocities of about 0.1 - 1.2 ms^-1, in both positive and negative pressure conditions, with an inlet air temperature (i.e., fluidizing gas temperature) in the range of -10 ° C or 5 ° C up to 100 ° C. In some cases it can be as high as 200 ° C.

The temperature of the fluidizing gas, and therefore preferably the bed temperature, may vary during the granulation process as described in WO 98/58048. It can be increased in the first period, for example to 100 ° C or even up to 200 ° C, and then in one or more other steps (before or after), it can be lowered to slightly above, equal to or below the ambient temperature, for example to 30 ° C or less, preferably 25 ° C or less, or even up to 5 ° C or less, or -10 ° C or less.

When the process is a bunker process, the temperature varies over time. If it is a continuous process, the changes occur along the "path" in the granulator bed (ie, in the direction of powder flow through the granulator bed). In the latter case, a "plug flow" granulator is conveniently used, ie one in which materials flow through the reactor from start to finish.

In a tank process, the temperature of the fluidizing gas may be reduced in a relatively short period of time, for example 10 to 50% of the process time. Typically, the temperature of the gas may be lowered for 0.5 to 15 minutes. In a continuous process, the gas temperature may be reduced over relatively short lengths of the "path" of the granulator bed, for example 10 to 50% of the way. In both cases, the gas may be pre-cooled.

Preferably, the temperature of the fluidizing gas, and preferably also the bed temperature, are not lowered until agglomeration of the fluidizing particles of the solid material is substantially complete.

PL 192 102 B1

In addition to the fluidizing gas, the gas fluidization granulator also uses an atomizing gas stream. This atomizing gas stream is used to assist in atomizing the liquid binder sprayed from the nozzle onto or into the fluidizing solid. The atomizing gas stream is generally used at a pressure of 2 x 10⁵ up to 5 x 10⁵ Pa (2 to 5 bar). The atomizing gas stream, usually air, is also heated.

According to a first aspect of the invention, the temperature of the fluidising gas is elevated to be in the range (plus or minus) of 25 ° C, more preferably in the range of 15 ° C, even more preferably in the range of 10 ° C, and suitably in the range of 5 ° C of a temperature capable of pumping (as defined herein) the liquid binder.

The temperature of the atomizing gas is also elevated to be in the range (plus or minus) of 25 ° C, more preferably in the range of 15 ° C, most preferably in the range of 10 ° C and suitably in the range of 5 ° C of the pumpable temperature of the liquid binder. .

The bed temperature in the fluidizing gas chamber may be elevated to be in the range (plus or minus) of 35 ° C, preferably in the range of 25 ° C, more preferably in the range of 15 ° C, even more preferably in the range of 10 ° C, and suitably in the range of within 5 ° C of the pumpable temperature of the liquid binder.

The temperature of the fluidizing gas and the atomizing gas is raised substantially as long as the liquid binder is sprayed onto the fluidizing solid.

It is especially preferred that the temperature of the fluidizing gas, as well as the temperature of the atomizing gas, are elevated and kept near a temperature permitting the pumping of the liquid binder.

It has been found that an increase, relative to the pumpable temperature of the liquid binder, of the temperature of the fluidising gas, and preferably also of the atomizing gas, is particularly advantageous when the liquid binder is a structured blend.

As used herein, the term "bed temperature" refers to the temperature of the fluidizing gas around the solid particulate material. The temperature of the bed can be measured, for example, with a thermocouple. Whether it is a perceptible powder bed or an imperceptible powder bed (i.e. when the mixer is operated at such a high gas flow rate that a classic "bubbling" fluidized bed is not formed, the "bed temperature" is taken to be the temperature measured at a point inside the fluidization chamber about 15 cm from the gas distribution plate.

Regardless of whether the gas fluidization process of the invention is a tank process or a continuous process, the solid particulate material can be introduced at any time while the liquid binder is sprayed. In the simplest form of the process, the solid particulate material is first introduced into a gas fluidization granulator and then the liquid binder is sprayed on. However, a portion of the solid particulate material may be introduced into the gas fluidization apparatus at the start of the process and the remainder may be introduced one or more times later, either as one or more separate feeds or continuously.

A gas fluidization granulator may optionally have a vibrating bed, especially for use in continuous operation.

Possible drying and / or cooling

The granular detergent product must be in a loose state for use, handling or storage. Thus, in the final step, the granules can be dried and / or cooled, if necessary. This step can be carried out in any known manner, for example in a fluidized bed apparatus (drying or cooling) or with a sparger (cooling). Drying and / or cooling can be performed in the same fluidized bed equipment as used in the final agglomeration step, simply by changing the process conditions, as is well known to those skilled in the art. For example, fluidization may continue for a period of time after the addition of the liquid binder is complete, after the temperature of the incoming gas has been reduced.

Other possible process steps

In more sophisticated embodiments of the process of the invention, the solid particulate material may be treated in one or more mixers and / or granulator prior to the gas fluidization granulator. For example, the solid particulate material may be mixed and optionally contacted with the liquid binder in a separate pre-mixing step, for example in a slow, medium or high shear mixer. If a liquid binder is added in the preliminary mixing step, a partially granulated material is formed. This material can then be sprayed with a remainder of the liquid binder in a gas fluidization granulator to produce a detergent product.

PL 192 102 B1

In this aspect, the fluid bed granulation step may be preceded by one or more separate mixing or granulating steps. Suitable mixers and granulators are well known to those skilled in the art. For example, the solid particulate material may first be treated with the liquid binder in a high shear mixer stage and then a medium shear mixer mixing stage prior to the gas fluidization stage.

Examples of suitable pre-granulation processes are described in EP-367339, EP-420317, WO 96/04359, WO 98/58046 and WO 98/58047 (Unilever), but other granulation and mixing processes are also suitable, as is evident for one skilled in the art.

The method according to the invention can be carried out both by the tank method and in a continuous manner. In a preferred embodiment, the entire process is a continuous process.

Liquid binder

In the process of the invention, the liquid binder is added during the granulation step in a gas fluidization granulator, and may also be added at other optional steps in the process.

If there is more than one granulation step or more than one point or time of addition, the liquid binder added at each such step or point or time may be the same or different, and more than one liquid binder may be added at any one step or at any time. point or time.

The liquid binder is sprayed in a gas fluidization granulator.

The liquid binder may contain one or more ingredients of the granular detergent product. Suitable liquid ingredients include anionic surfactants and their acid precursors, nonionic surfactants, fatty acids, water, and organic solvents.

The liquid binder may also include solid ingredients dissolved or dispersed in the liquid component, such as, for example, inorganic neutralizing agents and detergency builders. The only limitation is that with or without dissolved or dispersed solids, the liquid binder should be pumpable and suitable for delivery to the mixer and / or granulator in liquid, including pasty, form.

It is especially preferred that the liquid binder comprises an anionic surfactant. The anionic surfactant content of the liquid binder may be as high as possible, for example at least 98% by weight of the liquid binder, or may be less than 75% by weight, less than 50% by weight or less than 25% by weight. It may also be 5% by weight or less or not be present at all.

Suitable anionic surfactants are well known to those skilled in the art. Examples suitable for inclusion in the liquid binder include alkyl benzene sulfonates, especially linear alkyl benzene sulfonates having C8-C15 alkyl groups; primary and secondary alkyl sulfates, especially C12-C15 primary alkyl sulfates; alkyl ether sulfates, olefin sulfonates; alkyloxylene sulfonates, dialkyl sulfosuccinates and fatty acid sulfonate esters. The sodium salts are generally preferred.

It is very preferred to form part or all of the anionic surfactant in situ in the liquid binder by reacting a suitable acid precursor and an alkali material such as an alkali metal hydroxide, for example NaOH. Since the latter usually has to be added in the form of an aqueous solution, it has to introduce a certain amount of water into the process. Moreover, the reaction between the alkali metal hydroxide and the acid precursor also produces some water as a by-product.

While in general any alkaline inorganic material can be used for neutralization, water-soluble alkaline inorganic materials are preferred. Another preferred material is sodium carbonate, alone or in combination with one or more water-soluble inorganic materials, for example sodium bicarbonate or silicate. If desired, a stoichiometric excess of neutralizing agent may be used to provide complete neutralization or to provide alternative functions, for example as a detergency builder, for example when the neutralizing agent comprises sodium carbonate. Organic neutralizing agents can also be used.

Of course, if the liquid binder contains an acidic anionic surfactant precursor, the acid precursor may be neutralized, or the neutralization occurs in situ in the mixer and / or granulator by contacting both with the solid alkaline material and with the granulator.

And by adding, in a separate step, the liquid neutralizing agent to the mixer and / or granulator. However, neutralization in the mixer and / or granulator is not a preferred feature of this invention.

The liquid acid precursor can be selected from linear alkylbenzene sulfonic acids (LAS), alpha-olefin sulfonic acids, intra-olefinic sulfonic acids, fatty acid ester sulfonic acids, and combinations thereof. The process of the invention is particularly useful for preparing alkyl benzene sulfonate compositions by reacting a suitable alkyl benzene sulfonic acid, for example Dobanoic acid from Shell. Linear or branched primary alkyl sulfates (PAS) can also be used.

In a preferred embodiment, the liquid binder comprises an anionic surfactant and a non-ionic surfactant. The weight ratio of anionic to nonionic surfactant is in the range from 10: 1 to 1:15, preferably from 10: 1 to 1:10, more preferably 10: 1 to 1: 5. If the liquid binder comprises at least a portion of the acid precursor of the anionic surfactant and the nonionic surfactant, the weight ratio of the anionic surfactant including acid precursor to nonionic surfactant may be higher, for example 15: 1.

The nonionic surfactant component of the liquid binder may be one or more liquid non-ionic compounds selected from primary and secondary alcohol ethoxylates, especially C8-C20 aliphatic alcohols ethoxylated with an average of 1 to 20 moles of ethylene oxide per mole of alcohol, and more specifically an aliphatic primary and secondary alcohol. a C10-C15 secondary alcohol ethoxylated with an average of 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkylpolyglycosides, glycerol monoethers, and polyhydroxyamides (glucamide).

In a preferred embodiment of the invention, the liquid binder is substantially anhydrous. This means that the total water content of the binder is not more than 15% by weight, preferably not more than 10% by weight. Although, if desired, controlled amounts of water can be added to facilitate neutralization. Typically, water may be added in amounts of 0.5 to 2% by weight of the final detergent product. Typically, from 3 to 4% by weight of the liquid binder may be water as a by-product of the reaction, the remainder of the water present being the solvent in which the alkaline material is dissolved. The liquid binder preferably contains no water other than that from the above-mentioned sources, except, of course, in trace amounts of impurities.

Alternatively, an aqueous liquid binder may be used. This is particularly suitable for the manufacture of products that are adjuncts (additives) then mixed with the other ingredients to form a fully formulated detergent product. Such adjuncts typically, in addition to the liquid binder components, mainly consist of one or a few other components normally found in detergent compositions, for example a surfactant or builder such as zeolite or sodium tripolyphosphate. This does not preclude the use of aqueous liquid binders in the granulation of completely composed products. In each case, typical aqueous liquid binders include aqueous alkali metal silicate solutions, water-soluble acrylate / maleic polymers (e.g., Sokalan CP5), and the like.

The liquid binder may optionally contain soluble solid ingredients and / or finely divided solid ingredients dispersed therein. The only limitation is that with or without dissolved or dispersed solids, the liquid binder should be pumpable and sprayable at a temperature of 50 ° C or greater, or 60 ° C or greater, such as 75 ° C. It is preferably solid at a temperature of less than 50 ° C, preferably 25 ° C or less. The liquid binder is preferably at a temperature of at least 50 ° C, more preferably at least 60 ° C when introduced into the mixer or gas fluidization granulator.

According to the invention, liquid binders are considered easily pumpable if they have a viscosity of no more than 1 Pa s at a shear rate of 50 s.^-1 at pumping temperature. Higher viscosity liquid binders may still, generally be pumpable, but the upper limit is 1 Pa s at a shear rate of 50 s^-1 is used herein to indicate that the binder is easy to pump.

Viscosity can be measured, for example, with a Haake VT500 rotary viscometer. Viscosity measurement can be performed as follows. The measuring spindle SV2P connects to a thermostatic water bath with a cooling unit. The weight rotates at a shear rate of 50 s^-1. The solidified mixture is heated in the microwave to 95 ° C and poured into the basin

PL 192 102 B1 samples. After conditioning for 5 minutes at 98 ° C, the sample is cooled at a rate of +/- 1 ° C per minute. The temperature at which the viscosity is 1 Pa.s is recorded as the "pumpable temperature".

The "pumpable temperature" of a liquid binder is defined herein as the temperature at which the liquid binder exhibits a viscosity of 1 Pa s at a shear rate of 50 s.^-1. For a definition of a solid, see Handbook of Chemistry and Physics, CRC Press, Boca Raton, Florida, 67th edition, 1986.

Structured blends

In a preferred embodiment of the invention, the liquid binder comprises a structurant, the liquid binder containing the structurants is referred to herein as structured blends. All information on liquid binders is equally applicable to structured blends.

In the context of the invention, the term "structurant" means any component which enables the liquid component to solidify in the granulator and thus to granulate well even though the solid component has a low liquid absorption capacity.

Structurants may be categorized as having a structuring (solidification) effect by one or more of the following mechanisms, namely: recrystallization (e.g., silicate or phosphates); formation of a network of finely divided particles (for example silicates or clays); and those that exert steric effects at the molecular level (e.g., soaps or polymers), such as the types commonly used as detergent builders. One or more structurants may be used.

Structured blends have the advantage of a lower temperature at which they solidify with the consequent effect of imparting structure and strength to the particulate solid onto which they are sprayed. Thus it is important that the structured blend be pumpable and sprayable at elevated temperatures, for example at a temperature of at least 50 ° C, preferably at least 60 ° C, and should solidify at a temperature below 50 ° C, preferably below 35 ° C. C for beneficial effects.

Typically, in high speed, medium or low speed mixers the temperature is above 10 ° C, preferably more than 20 ° C below the temperature at which the blend was made and pumped into the granulator.

The structurants cause the liquid binder to solidify preferably to produce a strong blend in the following manner. The strength (hardness) of the solidified liquid component can be measured using an Instron pressure apparatus. A tablet 14 mm in diameter by 19 mm in height is produced of the solidified liquid component taken from the process prior to contact with the solid component. Then the tablet is broken between the fixed and moving plate, the movable plate moves towards the fixed plate. The plate speed is fixed at 5 mm / min, which results in the measured time being approximately 2 seconds. The computer plots the pressure curve. The maximum pressure (at the time of tablet breaking) is determined and the E modulus is calculated from the slope of the curve.

For the solidified liquid component, Pmax at 20 ° C is preferably a minimum of 0.1 MPa, more preferably 0.2 MPa, for example from 0.3 to 0.7 MPa. At 55 ° C, a typical range is 0.05 to 0.4 MPa. At a temperature of 20 ° C, the Emod of the liquid blend is preferably a minimum of 3 MPa, for example from 5 to 10 MPa.

The structured blend is preferably prepared in a dynamic shear mixer by mixing the ingredients and carrying out any neutralization of the anionic acid precursor.

Soaps are one of the preferred classes of structurants, especially when the structured blend comprises a liquid nonionic surfactant. In many cases, it may be desired that the soap has an average chain length greater than the average chain length of the liquid nonionic surfactant, but less than twice the average chain length of the latter.

It is very advantageous to prepare some or all of the soap structurant in situ in the liquid binder by reaction of a suitable fatty acid precursor and an alkali material such as an alkali metal hydroxide, for example NaOH. In general, any inorganic material can be used for neutralization, but water-soluble inorganic materials are preferred. In a liquid binder containing an anionic surfactant and soap, it is preferable to prepare both the anionic surfactant and soap from their respective acid precursors. All disclosures relating to the preparation of an anionic surfactant by in situ neutralization in a liquid binder from their respective acidic precursors simultaneously apply to the preparation of soap in structured blends.

If desired, the solid ingredients can be dissolved or dispersed in the structured blend. Typical amounts of the components of the structured blends in wt% of the structured blend are as follows:

preferably from 98 to 10% by weight of anionic surfactant, more preferably from 70 to 30% and most preferably from 50 to 30% by weight;

preferably from 10 to 98% by weight of a nonionic surfactant, more preferably from 30 to 70% by weight, most preferably from 30 to 50% by weight;

preferably from 2 to 30% by weight of the structurant, more preferably from 2 to 20%, even more preferably from 2 to 15% by weight and most preferably from 2 to 10% by weight.

In addition to the anionic surfactant or its precursor, nonionic surfactant and structurant, the structured blend may also contain other organic solvents.

Solid shredded material

The solid particulate materials used in the invention may be powdered and / or granulated. The solid particulate material can be any ingredient of the granular detergent product available in particulate form. Preferably, the solid particulate material with which the liquid binder is mixed is a detergency builder. In a particularly preferred embodiment of the invention, the solid particulate material comprises fillers selected from crystalline and amorphous aluminosilicates.

Product

A granular detergent product is obtained by the process of the invention (prior to any post-dosing or similar process).

The granular detergent product produced by the process of the invention has a bulk density of less than 900 g / l, preferably less than 800 g / l, more preferably less than 750 g / l, and even more preferably less than 700 g / l. The bulk density may be as low as 300 g / l, but is preferably greater than 400 g / l. Preferably it is in the range of 400-800 g / l, more preferably 400-750 g / l, even more preferably 400-700 g / l.

The product has a bulk density resulting from the nature of the process, but may be controlled to some extent by selecting appropriate mixing steps as will be apparent to those skilled in the art.

The granular detergent products according to the invention have a low fines content, good flowability and low UCT values.

Preferably less than 15 wt%, more preferably less than 10 wt% of the granules are less than 180 micrometers in diameter, more preferably less than 8 wt% and most preferably less than 5 wt%.

A granular product is considered to be free flowing (free flowing) if it has a DFR below 80 ml / s. Preferably the granular products have a DFR of at least 80 ml / s, preferably at least 90 ml / s, more preferably at least 100 ml / s and most preferably at least 110 ml / s.

The granular detergent product preferably has a UCT value of less than 1500 g, more preferably less than 1000 g, even more preferably less than 900 g and even more preferably less than 700 g and most preferably less than 500 g.

Granules can be distinguished from granules produced by other methods by the use of mercury porosimetry. This technique is ideal for characterizing granulates produced by a process involving gas fluidization agglomeration.

Detergent compositions and ingredients

As previously indicated, the granular detergent product according to the invention may itself be a fully packaged detergent composition, or it may be an ingredient or an adjuvant only part of the composition. This section of the description relates to the final, fully compiled detergent compositions.

The total amount of detergency builder in the final detergent composition is preferably from 10 to 80 wt%, more preferably from 15 to 60 wt%. The builder may be adjacent to the other ingredients or, if desired, separate builder particles containing one or more filler materials may be used.

PL 192 102 B1

The invention is particularly suitable when the solid starting material comprises fillers selected from crystalline and amorphous aluminosilicates, for example zeolites as described in GB-A-1,473,201; amorphous aluminosilicates as disclosed in GB-A-1,473,202; and mixed crystalline / amorphous aluminosilicates as disclosed in EP-B-164,514.

The aluminosilicates, whether used as layering agents and / or incorporated in the mass of the particles, may suitably be present in a total amount of from 10 to 60% by weight, preferably in an amount from 15 to 50% by weight based on the final weight of the detergent composition. The zeolite used in most commercial particulate detergent compositions is zeolite A. The maximum aluminum zeolite P (zeolite MAP) described and claimed in EP-A-384070 may preferably be used. Zeolite MAP is a P-type alkali metal aluminosilicate with a silicon to aluminum ratio not exceeding 1.33, preferably not exceeding 1.15, and more preferably not exceeding 1.07.

Other suitable fillers include hydrated salts, preferably in a significant amount such as at least 25% by weight of the solid component, preferably at least 10% by weight.

Hydratable solids include inorganic sulfates and carbonates as well as inorganic phosphate builders, for example sodium orthophosphate, pyrophosphate and tripolyphosphate.

Other inorganic fillers that may be present in the composition include sodium carbonate (as mentioned above, an exemplary hydrating solid) and, if desired, in combination with a calcium carbonate seed, as disclosed in GB-A1437950. As previously mentioned, sodium carbonate may be the residue of the inorganic alkali neutralizing agent used to generate the anionic surfactant in situ.

Organic anionic builders that may be present include polycarboxylate polymers such as polyacrylates, acrylic / maleic copolymers and acrylic phosphinates, monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, mono-, di- and tribosuccinates of glycerol, carboxymethalioniminetyls, hydroxymethaliminetyls, aminopolycarboxylates such as nitrilotriacetates (NTA), ethylenediaminetetraacetate (EDTA) and iminodiacetates alkyl and alkenyl malonates and succinates, and sulphonated fatty acid salts. A copolymer of maleic acid, acrylic acid and vinyl acetate is particularly preferred because they are biodegradable and therefore environmentally desirable. This list is not intended to be exhaustive.

Particularly preferred organic builders are citrates, suitably used in amounts of from 2 to 30% by weight, preferably from 5 to 25% by weight, acrylic polymers, more specifically acrylic / maleic copolymers suitably used in amounts of from 0.5 to 15% by weight, preferably from 1 to 10% by weight. The filler is preferably in the form of an alkali metal salt, especially a sodium salt.

Granular detergent compositions may contain, in addition to any anionic and / or nonionic surfactants, a liquid binder, one or more detergent active compounds which may be selected from soap and non-soap anionic, cationic, nonionic, amphoteric and zwitterionic surfactants and mixtures thereof . They can be post-dosed at any appropriate stage before or during the process. Many detergent active compounds are available, and they are widely described in the literature, for example in "Surface-Active Agents and Detergents" volumes I and II, Schwartz, Perry and Berch. The preferred detergent actives that can be used are soaps and synthetic non-soap anionic and nonionic compounds.

The detergent compositions may also contain a bleach system, a peroxy bleach compound, for example an inorganic persalt or organic peracid, capable of liberating hydrogen peroxide in aqueous solutions is desirable. The peroxy bleach compound may be used in conjunction with a bleach activator (bleach precursor) to improve bleaching performance at low wash temperatures. A particularly preferred bleach system comprises a peroxy bleach compound (preferably sodium percarbonate, optionally together with a bleach activator).

Typically, any bleach compounds and other sensitive ingredients such as enzymes and perfumes are post-dosed after granulation along with the other minor ingredients.

Typical minor components include sodium silicate, corrosion inhibitors including silicates, anti-redeposition agents such as cellulose polymers, fluorelants, inorganic salts such as sodium sulfate, foam regulators or foam boosters as needed, protolytic and lipolytic enzymes, dyes, colored particles, fragrances, foam regulating agents and fabric softening compounds. This list is not exhaustive.

Optionally, a "layering agent" or "flow aid" may be included at any appropriate stage in the process of the invention. They serve to improve the granulation of the product, for example by preventing aggregation and / or caking into the granule. Any free flow aids are suitably present in an amount of 0.1 to 15% by weight of the granular product, more preferably in an amount of 0.5 to 5% by weight.

Suitable layering / flow aid agents include crystalline or amorphous alkali metal silicates, aluminosilicates including zeolites, citrates, Dicamol, calcite, diatomaceous earths, silica, e.g. precipitated silica, chlorides such as sodium chloride, sulfates such as magnesium sulfate, carbonates such as calcium carbonate and phosphates such as sodium tripolyphosphate. Mixtures of these materials can also be used.

Zeolite MAP, as well as being the preferred filler, is particularly useful as a layering agent. Layered silicates such as SKS-6 from Clariant are also useful as layering agents.

Powder flow can also be improved by incorporating small amounts of additional powder structurant, for example fatty acid (or fatty acid soap), sugar, acrylate or acrylate / maleate polymer or sodium silicate, which are suitably present in amounts of 1 to 5 wt%.

In general, additional ingredients may be introduced in the liquid binder or mixed with the solid starting material at an appropriate stage in the process. However, the solid ingredients may be post-dosed into the granular detergent product.

The granular detergent composition may also contain a particulate filler (or any other ingredient that does not contribute to the washing process) which conveniently contains an inorganic salt such as sodium sulfate and sodium chloride. The filler may be present in an amount of 5 to 70% by weight of the granular product.

The invention will be described in more detail in the following non-limiting Examples, in which parts and percentages are by weight, unless otherwise indicated. The numbered examples are according to the invention and the lettered examples are comparative examples.

Examples

Example 1 and Comparative Example A

A granular detergent product was prepared in the form of a base powder with the following composition in% by weight:

Linear sodium alkylbenzenesulfonate (Na-LAS) 12.40

Non-ionic surfactant 7EO 12.81

Soap 1.73

Zeolite MAP 36.10

Light soda, dust 24.96

SCMC 0.81

Sodium citrate 3.33

Water, minorities, NDOM 7.86

100,00

SCMC - Sodium Carboxymethyl Cellulose NDOM - Insoluble Organic Substance The base powder in Example 1 was prepared by:

(i) mixing and granulating the solid ground materials with the liquid binder in a high-speed mixer (Lodige Recycler CB 30) for about 15 seconds, (ii) transferring the material from step (i) of the medium-speed mixer (Lodige Ploughshare KM 300) for about 3 minutes, ( iii) transferring the material from step (ii) to the fluidized bed in a gas fluidization granulator, adding further liquid binder and granulating, and (iv) finally drying / cooling the product in the fluidized bed.

PL 192 102 B1

The fluidized bed in step (iii) was operated for as long as a liquid binder was sprayed onto the fluidized solid under the following conditions.

Fluidizing gas temperature 75 ° C

Temperature of the atomizing gas hot ₅

Atomizing gas pressure 3.5 x 10⁵ Pa (3.5 bar)

The liquid binder used in steps (i) and (iii) was a structured blend containing anionic surfactant, nonionic surfactant and soap components of the base powder. A blend was prepared by mixing 38.44 parts by weight of LAS acid precursor and 5.20 parts by weight of fatty acid soap precursor in the presence of 41.60 parts by weight of nonionic surfactant in a mixing loop and neutralized with 14.75 parts of sodium hydroxide solution. The temperature of the mixing in the loop was controlled by the heat exchanger. The neutralizing agent was a sodium hydroxide solution. The mixture obtained had the following composition in% by weight:

Linear sodium alkylbenzene sulfonate 39.9

7EO non-ionic surfactant 41.6

Soap 5.6

Water 12.9

The pumpable temperature of the structured blend was 75 ° C.

The weight ratio of the blend added to the recycler and to the gas fluidization granulator was 67:33.

The base powder of Comparative Example A was prepared in the same manner except that the temperatures of the fluidizing gas and the atomizing gas were equal to the ambient temperature.

The properties of the powders obtained are shown in Table 1, these data clearly show the benefit of increasing the temperature of the fluidizing gas and the atomizing gas when spraying the liquid binder. The UCT value for the composition of Example 1 is significantly better than that of the compositions of Example A.

Table 1

<td></td><td>Example 1</td><td>Comparative example A.</td>

<td>bd (g / l)</td><td> 652</td><td> 593</td>

<td>DFR (ml / s)</td><td> 131</td><td> 117</td>

<td>UCT (g)</td><td> 200</td><td> 950</td>

Example 2 and Comparative Example B.

A granular detergent product was prepared in the form of a base powder with the following composition in% by weight:

Na-LAS 12.9

7EO 14.5 non-ionic surfactant

Soap 2.0

Zeolite A24 51.7

Light soda, dust 9.1

SCMC 0.95

Water, salts, NDOM 8.85

100,00

The base powder in Example 2 was prepared as in Example 1 except that the weight ratio of the blend added to the recycler and to the gas fluidization granulator was 80:20.

The mixture obtained had the following composition in% by weight:

Linear sodium alkylbenzene sulfonate 39.7

7EO non-ionic surfactant 44.7

Soap 6.0

Water 9.6

The pumpable temperature was 73 ° C.

PL 192 102 B1

The base powder of Comparative Example B was prepared in the same manner as Example 2 except that the temperature of the fluidizing gas was at ambient temperature (the temperature of the atomizing gas remained hot). The detailed properties of the powder are presented in Table 2.

When comparing the data for Example 2 and Comparative Example B, it is clear that increasing the temperature of the fluidizing gas leads to a marked improvement in the UCT value of the powder. The visual evaluation of the properties of the powders also shows a significant improvement. The composition of Comparative Example B looked tacky, whereas the composition of Example 2 was very well granulated with no coarse material or tacky.

Table 2

<td></td><td>Example 2</td><td>Comparative example B</td>

<td>BD (g / l)</td><td> 634</td><td> 554</td>

<td>DFR (ml / s)</td><td> 131</td><td> 130</td>

<td>UCT (g)</td><td> 450</td><td> 1950</td>

Example 3

The procedure of Example 2 was repeated with increasing both the temperature of the fluidizing gas and the atomizing gas. The powder had the following properties: