NO175010B - Detergent additive, process for its preparation, and detergent composition containing it - Google Patents

Description

This invention relates to detergent additive products in the form of particles or granules, methods for their production and their use in detergent mixtures. In particular, it relates to detergent additive-containing particles with improved mechanical strength and wear resistance as well as excellent dispersibility and

. resolution properties.

It is generally recognized that the function of a number of detergent additive materials can be significantly weakened in detergent mixtures by interaction between the additive material and other components in the mixture. E.g. enzymes, perfume, fluorescent agents, and bleach activators can adversely interact with peroxy bleaches; since organic bleach activators are usually hydrolyzable compounds, they tend to hydrolyze or perhydrolyze due to the action of moisture, alkaline substances and the percompound present in the detergent composition. Also, peroxyacid-bleach compounds and chlorine-bleach compounds, such as the chloroisocyanurates, when incorporated into detergent compositions, tend to attack oxidation-sensitive components such as perfumes, fluorescent agents and dyes. Cationic compounds can be affected in a harmful way by interaction with anionic constituents, e.g. anionic surfactants.

Numerous attempts have been made to improve the storage stability properties of detergent additive materials, such as bleach activators and the like, but such attempts have generally met with only limited success. The most common way of tackling the problem has been to protect the additive material from its adverse environment by agglomerating, coating or encapsulating the material with a non-hygroscopic, preferably hydrophobic material. Generally, organic materials have been most favored as coating/agglomerating agents because such materials easily form an essentially coherent and continuous plastic matrix, in which the additive material can be contained. GB A 1 2 04 12 3, GB A 1 441 416 and GB A 1 398 785 are representative of this general method.

In general, these descriptions teach the incorporation of a fine-particle bleach activator (hereinafter also referred to as peroxy acid bleach precursor), possibly with further stabilizing compounds, in larger agglomerates using organic solids with a melting point in the range of 30-60°C as agglomerating agents.

Unfortunately, however, protection of sensitive components in an organic plastic matrix as practiced in the prior art can have a detrimental effect on the component's dispersibility or dissolution properties in water, especially at low temperatures.

US patent 4,009,113 describes granular mixtures comprising approx. 40-80% of a bleach activator and an inert carrier material such as a long chain fatty acid or ester where the precursor is substantially uniformly distributed with the precursor compound forming a composite particle. The particle has an outer protective layer such as may consist of polyvinyl alcohol. The particles according to this patent can be produced by a one-step process using a machine called "Marumeriser" ® made by Fuji Pandal KK, or by a two-step process where the precursor/carrier mixture is processed by extrusion to form extrudates, which are then broken down into a "Marumeriser" and is formed into "spheres" and coating of the spherical particles. It is stated that such mixtures have both good storage stability and dispersibility in the washing water.

US patent 4 399 049 (=EP-A-0062523) describes a detergent additive comprising 75-95% (84-90%) of a particulate solid (e.g. bleach activator) with a particle size distribution such that at least approx. . 50% of the particles pass a 250 µm sieve, and 5-25% (10-16%) of ethoxylated non-ionic surfactant melts in the range 20-60°C, where the mixture is produced by a radial extrusion process. Such compositions are said to have improved storage stability as well as excellent release and dispersibility properties in wash water.

EP-A-0106634 describes activator-containing bodies comprising a bleach activator and an organic binder material with a melting point of not less than 40°C, where the bleach activator and the binder material are evenly distributed throughout the body, so that the body has the right density, produced by compression pressing or a radial extrusion process. It is stated that such bodies have both superior storage stability and dispersibility in the washing water.

In all these prior art descriptions, however, the main objective has been the formation of a bleach additive granule containing a peroxy bleach activator, whose chemical stability could be maintained in an adverse environment, e.g. when stored under conditions of elevated temperature and humidity in intimate contact with an alkaline peroxy bleach-containing detergent.

Since bleach activators, i.e. peroxy acid bleach precursors, are reactive compounds that act by forming peroxy acids in alkaline solutions containing a source of hydrogen peroxide, such as sodium perborate, a reaction often referred to as perhydrolysis, it is essential that detergent additive particles comprising a bleach activator, should be dispersed well and dissolve rapidly in the washing liquid while obtaining maximum benefit from their use. Other detergent additive materials will also benefit from these properties.

However, it is also highly desirable that the detergent additive material, especially peroxyacid bleach precursors, enzymes, fluorescent agents, germicides and chlorinated or peroxyacid bleach compounds, be formed into granulated particles or granules which have sufficient mechanical strength and wear resistance to be stored and transported safely by mass handling methods. The more aggressive the detergent additive material is, the more important this criterion will be.

It has been known how the first criterion must be fulfilled. It may also be known how the second criterion is to be fulfilled, but this has so far been at the expense of the requirements set for really good dispersibility and rapid dissolution of the particles.

The present invention seeks, as one of its purposes, to solve these conflicting requirements by providing granulated particles containing a detergent additive which will have the desirable properties that it is not brittle, not dusty and at the same time dissolves quickly.

Granulated particles, granules or particulate bodies in general should, in order to be classified as non-brittle, non-dusty and at the same time fast-dissolving, desirably show an abrasion value of less than 2%, preferably less than 1%; a dust formation of less than 1 mg/g, preferably less than 0.5 mg/g; and a resolution rate of less than 150 seconds, preferably less than 100 seconds.

According to the invention, a stable, non-brittle, non-dusty and at the same time fast-dissolving particulate detergent additive is provided which consists of bodies with sizes in the range of 100-2000 /xm, which comprise a detergent additive material which is enclosed in a water-soluble material in such a way that it can be released, which additive is characterized in that each body comprises a core particle comprising (a) 25-95 weight percent of a solid, particulate, storage-sensitive detergent additive material and (b) 75-5 weight percent of an organic binder material with a melting point of 25-80°C;

where (a) and (b) are substantially uniformly distributed throughout the core particle, which core particle is provided with 1-10 percent by weight of an outer coating of an organic material with a melting point below the melting point of the binder material of less than 60°C and solubility in water at 40°C of more than 20% by weight, and said bodies are in the form of substantially rounded particles with an average sphericity > 0.85 and a pore volume of not more than 0.25 cm<3>/g, and the product has a compressive strength expressed by a compression coefficient of more than 0.5 x 10<6>N/m<2>.

Preferred bodies will have a core particle comprising 50-90 weight percent of the solid particulate detergent additive material and 50-10 weight percent of the organic binder material. It is further preferred that a pore volume of less than 0.2 cm<3>/g is aimed for.

Definitions:

Sphericity is the ratio of the surface area of a sphere of the same volume as the particle to its true surface area, and can be determined by microscopy according to a method described by G. Herdan in "Small Particle Statistics", Butterworths, London, 2nd edition, 1960.

Pore volume is measured by mercury porosity measurement as described by T. Allen in "Particle Size Measurement", Champan and Hall, London, 3rd edition, 1980.

The compression coefficient of the particles is measured as follows:

A sieve fraction of granules in the order of 710-1000 µm is placed in a cylindrical press mold with a diameter of 16 mm and a depth of 6 mm. The granules are compressed by lowering a piston into the press mold, and at the same time the force is measured. The force required to produce a pressure of 30% (1.8 mm compression) is measured. This is then expressed as voltage and converted into a coefficient by dividing by the pressure (0.3).

The wear value is measured using a spray layer test, described in Iso/TC 47/WG 11, 1972, "Sodium perborate for industrial use, determination of rate of attrition" and the use of a 355-500 ixm sieve fraction of the granules.

The apparatus consists of a glass tube with diameter 25 mm, length 400 mm, mounted vertically. The lower end of the tube is fitted with a 3 mm thick stainless steel mouth plate with a 0.4 mm hole drilled in the middle. The plate is sealed to the pipe with flanges. The upper end of the tube is equipped with a removable dust filter. The tube orifice plate is supplied with nitrogen from a cylinder of compressed gas. The gas flow rate is adjusted using a pressure regulator to 7.0 ± 0.25 liters per minute, measured at atmospheric pressure.

A 50 gram sample of granules is fluidized for 10 minutes. Afterwards, the contents of the tube and filter are removed and the percentage of particles passing a 150 µm sieve is determined.

Dust formation is measured using a fluid bed dust compaction test and using a 1000-1400 /xm sieve fraction of granules. The vortex layer used has an inner diameter of 34.5 mm and is 2,000 mm high. Air is supplied to the layer at a surface gas velocity of 0.8 m/sec. through a sintered glass distributor. The layer is filled with 60 g of granules. Slumming is carried out for 40 minutes. Dirty dust is collected and weighed.

The dissolution rate is the time it takes for 90% of the detergent additive material to dissolve or disperse in water at 23°C, buffered at pH 10, in a standard test where a weight of 250 mg of granules is added to 500 ml of water in an agitated container, equipped with a magnetic stirrer of length 40 mm and diameter 9 mm rotated at 730 rpm (revolutions per minute).

Binder materials

The materials that can be used as binders include non-ionic surface-active agents, fatty acids, polyethylene glycols, anionic surface-active agents and mixtures of these with character properties as specified above and below. In some cases, water-insoluble materials such as silicone wax types, hydrocarbon wax types and triglycerides can also be used.

Examples of suitable non-ionic surfactants are the condensation products of primary and secondary aliphatic alcohols with 8-24 carbon atoms, with either a straight-chain or branched structure, which may be saturated or unsaturated, with 3-50 mol, preferably 3-25 mol, of ethylene oxide per . moles of alcohol. A specific example of this is tallow alcohol/ethylene oxide, which melts at approx. 40"C.

The preferred non-ionic surfactants in this class are prepared from primary alcohols which are partially branched, such as the dobanols and the neodols which have approx. 2 5% 2-methyl branching (Dobanol® and Neodol® are trademarks of Shell) or Synperonic compounds, which are known to have approx. 50% 2-methyl branching (Synperonic® is a trademark of ICI), or the primary alcohols with more than 50% branched structure, sold under the trade name Lial® by Liquichimica.

Other examples of non-ionic surfactants that can be used as binders are the condensation products of saturated or unsaturated, straight-chain or branched carboxylic acids with 8-24 carbon atoms with 3-50 mol, preferably 3-25 mol, of ethylene oxide per moles of carboxylic acid. Specific examples of non-ionic surfactants in this class are those produced from coconut fatty acid, palmitic acid, stearic acid and myristic acid.

Fatty acids that are useful in the present are e.g.

saturated or unsaturated fatty acids containing 8-24 carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, tallow acid or mixtures of tallow acid and coconut fatty acid, araic acid and behenic acid and mixtures thereof.

Suitable polyethylene glycols (PEGs), which are homopolymers of ethylene oxide with the general formula:

with an average molecular weight of from 400 to approx. 30,000, preferably from approx. 1,000 to 20,000, and most preferably from 1,500 to about 10,000. E.g. can these materials be obtained from the Dow Chemical Company with molecular weights of 1,500, 4,000, 4,500, 7,500,

9,500 and 20,000, which are wax-like products.

PEG 1500 has a melting point of approx. 40°C and solubility in water at 40°C of approx. 73%.

PEG 4000 has a melting point of approx. 55°C and solubility in water at 40°C of approx. 70%.

Suitable anionic surfactants are the water-soluble salts, preferably the alkali metal, ammonium and alkylolammonium salts, of organic sulphur-containing reaction products which in their

molecular structure has an alkyl group containing from 8-20 carbon atoms and a sulfonic acid or sulfuric acid ester group (included 1 the term "alkyl" is the alkyl part of acyl groups). Examples of this group of synthetic surfactants are the sodium and potassium alkyl sulphates, especially those obtained by sulphating the higher alcohols (C8-C18 carbon atoms) such as those produced by reducing the glycerides of tallow or coconut oil, and the sodium and potassium alkylbenzene sulphonates , where the alkyl group contains from approx. 9 to approx. 15 carbon atoms, with straight-chain or branched structure, e.g. such as are described in US patents 2,220,099 and 2,477,383. The preferred anionic surfactants are straight-chain alkylbenzene sulfonates, where the average number of carbon atoms in the alkyl group is 11-13, abbreviated as C11.13LAS.

Other anionic surfactants herein are the water-soluble salts of the higher fatty acids, ie "soap", which are suitable anionic surfactants in the compositions herein. These include alkali metal soaps such as the sodium, potassium, ammonium and alkylolammonium salts of higher fatty acids containing 8-24 carbon atoms, and preferably 12-18 carbon atoms. Soaps can be produced by direct saponification of fats and oils or by neutralization of free fatty acids.

Other anionic surfactants for use herein are the sodium alkyl glyceryl ether sulfonates, particularly such ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates; sodium or potassium salts of alkylphenol ethylene oxide ether sulfates containing 1-10 units of ethylene oxide per molecule and where the alkyl groups contain 8-12 carbon atoms; and sodium or potassium salts of alkyl ethylene oxide ether sulfates containing 1-10 units of ethylene oxide per molecule, and where the alkyl group contains 10-2 0 carbon atoms.

Other suitable anionic surfactants herein include the water-soluble salts of esters of alpha-sulfonated fatty acids containing 6-20 carbon atoms in the fatty acid group and 1-10 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-1-sulfonic acids containing 2-9 carbon atoms in the acyl group and 9-23 carbon atoms in the alkane moiety; water-soluble salts of olefin and paraffin sulfonates containing 12-20 carbon atoms; and beta-alkyloxyalkanesulfonates containing 1-3 carbon atoms in the alkyl group and 8-20 carbon atoms in the alkane moiety.

Mixtures of the above compounds, such as e.g. a mixture of a low-melting and a high-melting compound is also perfectly usable. Other suitable binder material mixtures are e.g. soap-fatty acid mixtures. It is also advantageous if polyethylene glycol is used for the incorporation of a surfactant (non-ionic and/or anionic) while improving wetting and dissolution.

Although the binder material's melting point is an important condition, there are no specific requirements with regard to the solubility and/or dispersibility in water of the binder material that can be imposed on all detergent additives in general.

E.g. it will be desirable that extremely insoluble detergent additive materials are mixed with extremely soluble binder materials to achieve the desired dissolution rate, and extremely soluble detergent additive materials may be sufficient together with less water-soluble or even water-insoluble binder materials, such as long-chain fatty acids and waxes materials.

In the case of peroxyacid bleach precursors, a suitable binder material should generally preferably have a solubility in water at 40°C of more than 20% by weight.

Beleaning materials

The same classes of materials which are suitable as binder materials, i.e. nonionic surfactants, fatty acids, polyethylene glycol, soap, anionic surfactants and mixtures thereof, are suitable for use as coating materials. However, it is desirable that a coating material should be chosen that has a lower melting point than the binder material used, so that the coating can be applied without changing the granule. Preferably, a coating material with a melting point of at least 5°C below the melting point of the binder material used is used. Specific examples of a coating material are PEG 300 (m.p. from -15 to 8°C), PEG 400 (m.p. from 4 to 8°C) and PEG 600 (m.p. from 22°C), which are very soluble materials with low viscosity .

The manufacturing process

The particulate detergent additive according to the invention can be produced by a mixing method with high shear. In the method, a high-speed mixer/granulator equipment is used which has both a high-energy stirring effect and a cutting effect. Equipment for processing at high shear can generally be divided according to whether the mixing shaft, to which a mixing paddle wheel or several mixing paddle wheels are attached, is mounted vertically or horizontally. When the shaft is vertical, a single mixing paddle wheel rotating in a horizontal plane is fitted inside a tightly fitting bowl-shaped container. The rotation of the paddle wheel results in the mixing of powders with a high shear force. When the shaft is horizontal, one or more mixing paddle wheel blades rotating in a vertical plane are mounted inside a tightly fitting cylindrical container. Rotation of the paddle wheel blades provides mixing of the powder with a high shear force. In addition, it is common practice that small chopper blades are mounted inside the container which rotate at approx. 1,000 rpm or more, and which serves to dissolve oversized material formed during agglomeration. Both types of these high-speed mixers/granulators are commercially available and can be used for the production of the detergent additive-containing bodies according to the invention as rounded, mechanically strong particles.

The Fukae (trademark) FS-G mixer manufactured by Fukae Powtech Kogyo Co., Japan has been shown to give excellent results in batch operation. This apparatus is essentially in the form of a container accessible via a top opening, provided near its bottom with a stirrer having a substantially vertical axis, and a cutting device arranged on a side wall. Preferably, the stirrer and the cutting device can be operated independently of each other and at separate variable speeds, whereby the method can be regulated and adjusted according to changes in preparations.

Other mixers suitable for use in the method of the invention include the Diosna (Trade Mark) V series from Dierks & Sohne, Germany; the Lodige (trademark) FM ("ploughshare" mixer) series from Morton Machine Co. Ltd, Scotland; and Pharma Matrix (trademark) from T.K. Fielder Ltd, England. Other mixers believed to be suitable for use in the process of the invention are the Fuji (trademark) VG-C series from Fuji Sangyo Co., Japan; Lodige MTG from Morton Machine Co. Ltd, Scotland and Roto (trademark) of Zanchetta & Co. S.r.l., Italy. The Lodige mixer differs from the Fukae mixer mentioned above in that its stirrers have a horizontal axis; this structure is suitable for continuous operation.

The use of a mixing process with a high shear force is highly desirable for the formation of the detergent additive-containing bodies according to the invention, which, with a suitable selection of the binder and a suitable selection of the coating as described herein, will be mechanically strong and highly abrasion-resistant and yet quickly -dissolving.

Other known agglomeration processes by which a fine powder can be converted into a granular powder and which can be classified as: i) low shear mixing processes;

ii) fluidized bed processes (also called fluidized bed processes) and processes involving the use of a

air flow; and

iii) compaction processes,

are not excluded, but they may be less suitable for achieving the desired results.

Low shear mixing processes include the use of pans, drums and low energy mechanical mixers. These usually give irregularly shaped, weak, porous granules which are not well-suited for handling in bulk because they can easily cause wear, although the porous nature of the particles can contribute to a good dissolution value.

Fluidized bed processes and processes involving the use of air currents generally produce porous, mechanically weak, but fast-dissolving granules. The mechanical weakness of the granules makes them unsuitable for the purpose of the invention.

Compression processes include the various extrusion and tableting processes. They generally give granules with defined shape-characteristics, e.g. cylindrical particles (sometimes referred to as "noodles") and tablets. The strength of the granules depends on the pressure and other processing conditions and on the type and level of the binder used, and can vary over a very large area. Granules prepared by compaction methods and having adequate strength for pulp handling usually dissolve slowly. Due to their shape and internal tension, structure and consistency built into the process, they tend to burst and will be able to wear.

In one preferred form of the invention, the invention consequently provides stable, non-brittle, non-dusty and at the same time fast-dissolving detergent additive-containing bodies as defined herein, and which can be obtained by a mixing process with high shear force using a high-speed mixer /- granulator.

Two main processing steps characterize the production of the bodies, namely 1) granulation to form the core particles and 2) coating of the core particles to form the finished bodies. Both processes can be carried out sequentially in the same high-speed mixer/granulator, or the core particles obtained from the high-speed mixer/granulator can be taken out and coated in another suitable mixer, such as a fluid bed mixer, a rotary inclined pan granulator, rotary drum mixer, drum mixer, V- mixers, plowshare mixers and belt mixers.

The organic binder material can be filled into the mixer/granulator in solid or liquid form. In both cases, it is important to maintain the temperature during granulation slightly above the melting point of the binder material, whereby the binder material is in a state where it can form a matrix with the solid, particulate detergent additive material.

It is desirable that the core particles are cooled before the coating. This can be done in a number of ways, e.g. inside the high-speed mixer/granulator, by trough cooling, rotating drum cooling and using the cooling effect of pneumatic conveying. A preferred cooling method is to use a swirl bed where air at ambient temperature, or cooled to below ambient temperature, is supplied to the particle layer by means of a distribution plate. The fluidized bed can be operated in batches or continuously.

It may also be desirable to sieve the particulate mass to remove coarse material. This material may consist of granules or oversized material that has been compressed in the device and then torn loose. If desired, fine material can also be removed by sieving or another suitable size classification method. These screening operations can be performed before cooling, after cooling or after coating.

In another aspect, the invention thus provides a

method for producing a particulate detergent additive product, comprising the following steps: 25-95 parts by weight of a solid, particulate, storage-sensitive detergent additive material is treated in a high-speed mixer/granulator in the presence of 75-5 parts by weight of an organic binder material having a melting point of 25-80 °C, whereby granulation and spherification are carried out; nuclear particle

lene is formed, followed by cooling and addition of an organic material with a melting point below the melting point of the binder material of less than 60°C, and a solubility in water at 40°C of more than 20% by weight, whereby coating of the core particles is carried out, forming bodies with a substantially rounded shape with an average sphericity > 0.85 and a pore volume of not more than 0.25 cm<3>/g and a compressive strength expressed by a compression coefficient greater than 0.5 x 10<6>N/m<2> .

The detergent additive material

The detergent additives that can be used in the present invention can be selected from any group of solid, particulate, storage-sensitive detergent additive materials.

Preferred detergent additives are enzymes, peroxyacid compounds, peroxygen and chlorine bleaches, fluorescent agents and peroxyacid bleach precursors. A highly preferred detergent additive material, however, is an organic peroxy acid bleach precursor. Another highly preferred material is a peroxy acid compound.

For the sake of simplicity, the invention will be further described with special reference to peroxy acids and peroxy acid bleach precursors.

Examples of the various classes of peroxyacid bleach precursors include: (a) N-diacylated and N,N'-polyacylated amines, such as N,N,N',N'-tetraacetylmethylenediamine and N,N,N',N '-tetraacetylethylenediamine, N,N-diacetylaniline, N,N-diacetyl-p-toluidine; 1,3-diacylated hydantoins such as e.g. 1,3-diacetyl-5,5-dimethylhydantoin and 1,3-dipropionylhydaritoin; (b) N-alkyl-N-sulfonylcarbonamides, e.g. the compounds N-methyl-N-mesylacetamide, N-methyl-N-mesylbenzamide, N-methyl-N-mesyl-p-nitrobenzamide and N-methyl-N-mesyl-p-methoxybenzamide; (c) N-acylated cyclic hydrazides, acylated triazones or urazoles, e.g. monoacetylmaleic acid hydrazide; (d) 0,N,N-trisubstituted hydroxylamines, such as 0-benzoyl-N,N-succinylhydroxylamine, O-acetyl-N,N-succinylhydroxylamine, 0-p-methoxybenzoyl-N,N-succinylhydroxylamine, O-p-nitro-benzoyl -N,N-succinylhydroxylamine and O,N,N-triacetylhydroxylamine; (e) N,N'-diacylsulfuryl amides, e.g. N,N'-dimethyl-N,N'-diacetylsulfurylamide and N,N'-diethyl-N,N'-dipropionylsulfurylamide; (f) Triacyl cyanurates, eg triacetyl cyanurate and tribenzoyl cyanurate; (g) Carboxylic anhydrides, such as benzoic anhydride, m-chlorobenzoic anhydride, phthalic anhydride and 4-chlorophthalic anhydride; (h) Sugar residues, e.g. glycosepentaacetate; (i) 1,3-diacyl-4,5-diacyloxy-imidazolidine, e.g. 1,3-di-formyl-4,5-diacetoxy-imidazolidine, 1,3-diacetyl-4,5-diacetoxy-imidazoline, 1,3-diacetyl-4,5-dipropionyloxy-imidazoline; (j) Tetraacetyl glycoluril and tetrapropionyl glycoluril; (k) Diacylated 2,5-diketopiperazine, such as 1,4-diacetyl-2,5-diketopiperazine, 1,4-dipropionyl-2,5-diketopiperazine and 1,4-dipropionyl-3,6-dimethyl-2,5 -diketopiperazine; (1) Acylation products of propylene diurea or 2,2-dimethyl-propylene diurea (2,4,6,8-tetraazabicyclo-(3,3,1)-nonane-3,7-dione or its 9,9-dimethyl derivative), in particular the tetraacetyl or tetrapropionyl propylenediurea compound or their dimethyl derivatives; (m) Carbonic acid esters, e.g. the sodium salts of p-(ethoxycarbonyloxy)benzoic acid and p-(propoxycarbonyloxy)benzenesulfonic acid;

(n) α-acyloxy-(N,N')-polyacylmalonamides, such as α-acetoxy-(N,N')-diacetylmalonamide.

(o) Acylphenolsulfonates and acylalkylphenolsulfonates, such as sodium p-acetoxybenzenesulfonate,

sodium p-nonanoyloxybenzenesulfonate, and

sodium p-trimethylhexanoyloxybenzenesulfonate.

These and other classes of peroxyacid bleach precursors are known and fully described in the literature, such as in GB patents 836,988, 864,798, 907,356, 1,003,310 and 1,519,351; German Patent 3,337,921; EP-A-0185522; EP-A-0174132; EP-A-0120591 and US Patents 1,246,339, 3,332,882, 4,128,494, 4,412,934 and 4,675,393.

Another useful class of peroxyacid bleach precursors is the class of the quaternary ammonium substituted peroxyacid precursors described in US Patents 4,751,015 and 4,397,757, in EP-A-284292 and EP-A-331229. Examples of peroxyacid bleach precursors in this class are: 2-(N,N,N-trimethylammonium)ethyl sodium 4-sulfophenylcarbonate chloride - (SPCC);

N-octyl-N,N-dimethyl-N10-carbophenoxydecylammonium chloride -

(ODC);

3-(N,N,N-trimethylammonium)propyl sodium 4-sulfophenylcarboxylate; and

N,N,N-trimethylammonium toluyloxybenzenesulfonate.

Among the above bleach precursor classes, the preferred classes are the esters, including acylphenol sulfonates and acylalkylphenol sulfonates; amides, including TAED; and the quat.-ammonium-substituted peroxyacid precursors, especially SPCC.

Specific preferred materials are solid and are incorporated into the present bodies, particles or granules in finely divided form, i.e. with an average particle size of less than 250 µm, preferably less than 200 µm, especially with a main particle size of between 50 and 150 µm.

Most preferred activators include sodium 4-benzoyloxybenzenesulfonate; sodium p-trimethylhexanoyloxybenzenesulfonate; sodium 1-methyl-2-benzoyloxybenzene-4-sulfonate; sodium 4-methyl-3-benzoyloxybenzoate; SPCC and trimethylammonium toluyloxybenzenesulfonate, among which sodium 4-benzoyloxybenzenesulfonate and 2-(N,N,N-trimethylammonium)ethyl sodium 4-sulfophenyl carbonate chloride are particularly preferred.

Peroxy acid compounds include the organic peroxy acids and their acids and the inorganic peroxy acid salts, which are solid at room temperature and preferably have a melting point above 50°C.

Suitable organic peroxyacids can be represented by the compounds of the general formula: where R is an alkylene or substituted alkylene group containing 1-20 carbon atoms, or an arylene group containing from 6-8 carbon atoms, n is 0 or 1, and Y is hydrogen, halogen, alkyl, aryl or any group which provides an anionic or cationic moiety in aqueous solution. Such groups may include, for example:

where M is H or a water-soluble, salt-forming cation.

The organic peroxyacids and their salts can contain either one, two or more peroxy groups and can be either aliphatic or aromatic. When the organic peroxyacid is

aliphatic, the unsubstituted acid may have the general formula:

where Y can be H,

and m can be an integer from 1-20.

Specific examples of compounds of this type are deperoxyazelaic acid, peroxylauric acid and 1,12-diperoxydodecanedic acid, and the magnesium salts thereof.

When the organic peroxyacid is aromatic, the unsubstituted acid may have the general formula: where Y e.g. is hydrogen, halogen, alkyl,

The percarboxy or percarboxylic acid and Y groups may be in any relative position around the aromatic ring. The ring and/or the Y group (if alkyl) may contain any non-interacting substituents, such as halogen or sulfonate groups.

Specific examples of such aromatic peroxyacids and salts thereof include peroxybenzoic acid, m-chloroperoxybenzoic acid, p-nitroperoxybenzoic acid, p-sulfonate-peroxybenzoic acid, diperoxyisophthalic acid, peroxy-alpha-naphthoic acid and 4,4'-sulfonyl-diperoxybenzoic acid and magnesium salts thereof.

Another suitable peroxyacid class is the class of imido-aromatic (poly)peroxycarboxylic acids as described in EP-A-325289 with the general formula: where A is an optionally substituted benzene ring and n is an integer from 1 to 12, preferably 5.

A specific compound that represents the class is N,N-phthaloylamino-peroxycaproic acid.

A specific example of inorganic peroxyacid salts is potassium monopersulfate. A product comprising this compound is the triple salt K2SOA-KHSOA-2KHS05, which is commercially available under the trade name Oxone® from E.I. Dupont de Nemours & Co.

Suitable enzymes include the amylolytic, lipolytic and proteolytic enzymes suitable for incorporation into detergent compositions.

Preferred proteolytic enzymes are usually solid, catalytically active protein materials which degrade or change protein spot types found e.g. like fabric stains, by a hydrolysis reaction. They may be prepared from any suitable origin, such as vegetable, animal, bacterial or yeast origin.

Proteolytic enzymes or protease of different quality and origin and with activity in different pH ranges of 4-12 are available and can be used in the present invention. Examples of suitable proteolytic enzymes are the subtilisins, which are obtained from special strains of B. subtilis and B. licheniformis, such as the commercially available subtilisins Maxatase®, supplied by Gist-Brocades N.V., Delft, Holland, and Alcalase® supplied by Novo Industri A/ S, Copenhagen, Denmark.

Particularly suitable is a protease obtained from a strain of Bacillus with maximum activity throughout the pH range 8-12, and which is commercially available, e.g. from Novo Industri A/S under the registered trade names Esperase® and Savinase®. The preparation of these and analogous enzymes is described in British Patent 1 24 3 785. Other commercial proteases are Kazusase® (supplied by Showa-Denko, Japan), Optimase® (from Miles Kali-Chemie, Hannover, West Germany) and Superase® (provided by Pfizer, U.S.A.).

Fluorescent brighteners are well-known materials, examples of which are disodium 4,4'-bis-(2-diethanolamino-4-anilino-s-triazin-6-ylamino)stilbene-2:2'-disulfonate, disodium-4, 4'-bis-(2-morpholino-4-anilino-s-triazin-6-ylaminostilbene-2:2'-disulfonate, disodium 4,4'-bis-(2,4-dianilino-s-triazine-6 -ylamino)stilbene-2:2'-disulfonate, disodium 4,4'-bis-(2-anilino-4-

(N-methyl-N-2-hydroxyethylamino)-s-triazin-6-ylamino)stilbene-2, 2'-disulfonate, disodium 4,4'-bis-(4-phenyl-2,1,3-triazole -2-yl)stilbene-2,2'-disulfonate, disodium 4,4'-bis(2-anilino-4-(1-methyl-2-hydroxyethylamino)-s-triazin-6-ylamino)stilbene -2,2'-disulfonate and sodium 2(stilbyl-4''-naphtho-1',2':4,5)-1,2,3-triazole-2''-sulfonate

Other fluorescent agents which can be used in the invention include the 1,3-diarylpyrazolines and the 7-alkylaminocoumarins.

In addition, the particulate detergent additive bodies according to the invention can also contain other components as desired to improve dissolution or other properties. These additional components, if present, are preferably incorporated in admixture with the detergent additive material in the core particle. Examples of such additional ingredients are: i) Water-soluble inorganic or organic salts which can be acidic or neutral salts, such as sodium or potassium mono- or dihydrogen phosphates, sodium or potassium hydrogen sulphate, ammonium salts of strong acids, e.g. ammonium sulphate, sodium or potassium sulphate and chloride, and citrates. ii) Acidic materials such as citric acid, and water soluble polymeric materials such as low molecular weight homo- and copolymers of

acrylic acid and their salts.

iii) Non-ionic compounds such as sugars, e.g.

sucrose and fructose; and polyvinylpyrrolidone (PVP).

iv) Surfactants, if not already included below

binders.

v) Water-insoluble materials, such as clays and antifoams

funds.

vi) Dispersants and water-swellable materials, such as modified starch compounds, modified cellulose compounds, powdered cellulose, cellulose fibers, cross-linked PVP and starch ethers, e.g. carboxymethyl cellulose.

vii) Stabilizers, such as ethylenediaminetetra-(methylenephosphonic acid),

diethylenetriaminepenta-(methylenephosphonic acid), ethylenediaminetetraacetic acid, and their salts.

Any of these optional constituents may be present in the core particle at a total level of up to about 60% by weight, based on the core particle, preferably not more than 25% by weight.

As explained above, the new detergent additive-containing bodies (particles or granules) according to the invention are very well suited for incorporation into washing powder mixtures.

Accordingly, detergent mixtures comprising the particulate detergent additive product as described herein are within the scope of the present invention.

When the detergent additive material is a bleach activator (a peroxyacid bleach precursor), the detergent mixture requires as an essential component a peroxide bleach compound which can give hydrogen peroxide in aqueous solution.

Hydrogen peroxide sources are well known in the art. They include the alkali metal peroxides, organic peroxide compounds such as urea peroxide and the inorganic persalts such as the alkali metal perborates, percarbonates, perphosphates and persulfates. Mixtures of two or more such compounds may also be suitable. Particularly preferred is sodium perborate tetrahydrate and especially sodium perborate monohydrate. Sodium perborate monohydrate is preferred because it has excellent storage stability, while it also dissolves very quickly in aqueous bleach solutions. This rapid dissolution will further contribute to the formation of higher levels of peroxycarboxylic acid, whereby the surface bleaching ability is increased.

The molar ratio between hydrogen peroxide (or a peroxide compound that forms the equivalent amount of H 2 O 2 ) and precursor can typically be in the range from 0.5:1 to about 20:1, preferably from 1:1 to 5:1, most preferably from 1:1 to 2:1.

A detergent preparation containing the bleach activator granules according to the invention will usually also contain surface-active materials, detergent builders and other known ingredients in such preparations.

In such preparations, the bleach activator granules can be incorporated in an amount where the peroxy acid bleach precursor is present at a level in the range from approx. 0.1-20% by weight, preferably from 0.5-10% by weight, especially from 1-7.5% by weight, together with a peroxide-bleach compound, e.g. sodium perborate mono- or tetrahydrate, the amount of which is usually within the range from 2 to 40% by weight, preferably 4-30% by weight, especially 10-25% by weight.

The surface-active material may be of natural origin, such as soap, or it may be a synthetic material selected from anionic, non-ionic, amphoteric, zwitterionic, cationic active materials and mixtures thereof. Many suitable active materials are commercially available and are fully described in the literature, e.g. in "Surface Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch. The total level of the surfactant may be in the range of up to 50% by weight, preferably 1-40% by weight, based on the mixture, most preferably 4-25%.

The detergent mixtures according to the invention will normally also contain a detergency builder. Building materials may be selected from 1) calcium sequestering materials, 2) precipitation materials, 3) calcium ion exchange materials and 4) mixtures thereof.

Examples of calcium sequestering builders include alkali metal polyphosphates such as sodium tripolyphosphate; nitrile triacetic acid and its water-soluble salts; the alkali metal salts of carboxymethyloxysuccinic acid, ethylenediaminetetraacetic acid, oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, citric acid and polyacetal carboxylates as described in US patents 4,144,226 and 4,146,495.

Examples of precipitation builders include sodium orthophosphate, sodium carbonate, and long-chain fatty acid soaps.

Examples of calcium ion exchange building materials include the various types of water-insoluble crystalline or amorphous aluminum silicates, among which zeolites are the best known representatives.

The mixtures according to the invention can in particular contain any of the organic or inorganic building materials, such as sodium or potassium tripolyphosphate, sodium or potassium pyrophosphate, sodium or potassium orthophosphate, sodium carbonate, the sodium salt of nitrile triacetic acid, sodium citrate, carboxymethyl malonate, carboxyethyl oxysuccinate and the water-insoluble crystalline or amorphous aluminosilicate building materials, or mixtures thereof.

These building materials can be present at a level of e.g. 5-80% by weight, preferably 10-60% by weight.

In addition to the components already mentioned, the detergent mixtures according to the invention can contain any of the usual additives - if not already incorporated in the present granules - in the quantities where such materials are usually used in laundry detergent mixtures. Examples of these additives include foaming agents such as alkanolamides, especially the monoethanolamides derived from palm kernel fatty acids and coconut fatty acids, antifoaming agents such as alkyl phosphates and silicones, anti-redeposition agents such as sodium carboxymethyl cellulose and alkyl or substituted alkyl cellulose ethers, peroxide stabilizers such as ethylenediaminetetraacetic acid and preferably phosphonates, e.g. ethylenediaminetetramethylenephosphonic acid and diethylenetriaminepentamethylenephosphonic acid or their salts, fabric softeners, inorganic salts such as sodium sulfate, and, usually present in very small amounts, fluorescent agents, perfumes, enzymes such as proteases, cellulases, lipases and amylases, germicides and dyes.

The following examples will illustrate the embodiments of the invention more fully. All parts, percentages and shares mentioned herein are by weight unless otherwise illustrated.

Examples I-X

The following bleach activator granules of compounds I-X were prepared in a Fukai (trademark) type high speed mixer/granulator. All the granules obtained had the shape of rounded particles with an average sphericity around 0.9 and had pore volumes of less than 0.15 cm<3>/g. The wear value, dust formation, compression coefficient and dissolution rate of each granule mixture were determined and the results, as listed below, show excellent physical properties of high mechanical strength combined with good dissolution rate.

Example XI

Preparation of bleach activator granules according to examples I-X

Into a Fukae® model FS-GC-30 high speed mixer/granulator was charged 6 kg of the bleach precursor (SBOBS or TAED) with or without the optional ingredients sodium sulfate, sucrose and cellulose fibers, as required. The temperature was regulated at 55°C using the water jacket. The molten binder (PEG 4000 or PEG 1500 or Dobanol 45/11 EO or PEG 1500 + Synperonic A7) was poured into the granulator over a period of 1 minute, during which time the mixing paddle wheel was rotated at 100 rpm and the chopper blades was rotated at 3,000 rpm. Mixing was then continued for a further 9 minutes.

Granulation was carried out over a period of 5 minutes, with one revolution of the mixing paddle wheel at 300 rpm and rotation of the chopper blades at 3,000 rpm. The temperature was then reduced to 20°C by means of the cooling jacket, and the speed of the mixing paddle wheel was reduced to 70 rpm and the speed of the chopper blades to 1000 rpm. After cooling for 10 minutes, the coating liquid (PEG 400) was added, and after a further 5 minutes the product was withdrawn. The product obtained contains a major proportion of granules with a size between 350 and 1400 µm.

Examples XII-XIII

The following peroxyacid granules of mixtures XII and XIII were prepared in a Lodige® type high speed mixer/granulator. All the obtained granules had the form of rounded particles with an average sphericity around 0.9 and a pore volume of less than

0.2 cm<3>/g. The wear value, compression coefficient and dissolution rate of each granule mixture were determined and the results, as listed below, show excellent physical properties with high mechanical strength combined with a good dissolution rate.

Example XIV

Preparation of bleaching agent granules according to examples XII-XIII

The peroxyacid bleach granules were prepared with a Lodige model M4 ELOD high-speed mixer/granulator. The granulator was filled with 0.450 kg of the peroxy acid bleach and the appropriate weight proportions of sodium sulfate and lauric acid. The temperature was regulated at 50°C by blowing hot air over the granulator. The granulation was carried out over a period of

2 minutes while the mixing paddle wheel rotated at 300 rpm.

The prepared granules were removed and cooled for 10 minutes in a laboratory fluidized bed type Aeromatic (trade mark)

(model STREA-l).

The granules were sieved to remove particles above

1400 films. Coatings were applied in a drum mixer at a temperature of 30°C.

Claims (21)

1. Particulate detergent additive product consisting of detergent additive-containing bodies with sizes in the range of 100-2000 / µm, comprising a detergent additive material which is enclosed in a water-soluble material in such a way that it can be released, characterized in that each body comprises a core particle comprising: (a) 25-95 percent by weight of a solid, particulate, storage-sensitive detergent additive material, and (b) 75-5 percent by weight of an organic binder material having a melting point of 25-80°C, where ( a) and (b) are substantially uniformly distributed throughout the core particle, which core particle is provided with 1-10 percent by weight of an outer coating of an organic material with a melting point below the melting point of the binder material of less than 60°C and a solubility in water at 40 °C of more than 20% by weight, and the bodies are in the form of mainly rounded particles with an average sphericity > 0.85 and with a pore volume of not more than 0.25 cm<3>/g; and the product has a compressive strength expressed by a compression coefficient greater than 0.5 x IO<6>N/m<2>. 2. Detergent additive product according to claim 1, characterized in that the core particle comprises 50-90 percent by weight of the solid, particulate, storage-sensitive detergent additive material and 50-10 percent by weight of the organic binder material. 3. Detergent additive product according to claim 1 or 2, characterized in that the pore volume is less than 0.2 cm<3>/g. 4. Detergent additive product according to claim 1, 2 or 3, characterized in that the binder material is selected from the group consisting of non-ionic surfactants, fatty acids, polyethylene glycols and anionic surfactants, and mixtures thereof. 5. Detergent additive product according to any one of claims 1-4, characterized in that the coating material is selected from the group consisting of non-ionic surfactants, fatty acids, polyethylene glycols and anionic surfactants, and mixtures thereof, with a lower melting point than the binder material. 6. Detergent additive product according to any one of claims 1-5, characterized in that the coating material has a melting point of at least 5°C below the melting point of the binder material. 7. Detergent additive product according to any one of claims 1-6, characterized in that the detergent additive is selected from the group consisting of enzymes, peroxyacid compounds, peroxygen and chlorine bleaches, fluorescent agents and peroxyacid bleach precursors. 8. Detergent additive product according to claim 7, characterized in that the detergent additive is a peroxyacid bleach precursor. 9. Detergent additive product according to claim 8, characterized in that the peroxyacid bleach precursor is sodium 4-benzoyloxybenzenesulfonate. 10. Detergent additive product according to claim 8 or 9, characterized in that the binder material has a solubility in water at 40°C of more than 20% by weight. 11. Process for the production of a particulate detergent additive product according to any one of the preceding claims, characterized in that it comprises the following steps: 25-95 percent by weight of a solid, particulate, storage-sensitive detergent additive material is processed in a high-speed mixer/granulator in the presence of 75-5 parts by weight of an organic binder material with a melting point of 25-80°C, by which granulation and spherification are carried out; the core particles are formed, followed by cooling and addition of an organic material with a melting point below the melting point of the binder material of less than 60°C and a solubility in water at 40°C of more than 20% by weight, whereby the coating of the core particles takes place; bodies of a predominantly rounded shape with average sphericity are formed > 0.85, a pore volume of not more than 0.25 cm<3>/g and a compressive strength expressed by a compression coefficient greater than 0.5 x 10<6> N/m<2.> 12. Method according to claim 11, characterized in that the granulation is carried out at a temperature slightly above the binder material's melting point. 13. Method according to claim 11 or 12, characterized in that 50-90 parts by weight of the detergent additive material is treated in the presence of 50-10 parts by weight of the liquid organic binder material. 14. Method according to any one of claims 11-13, characterized in that the binder material is selected from the group consisting of non-ionic surfactants, fatty acids, polyethylene glycols and anionic surfactants, and mixtures thereof. 15. Method according to any one of claims 11-14, characterized in that the coating material is selected from the group consisting of non-ionic surfactants, fatty acids, polyethylene glycols and anionic surfactants, and mixtures thereof, with a lower melting point than the binder material. 16. Method according to any one of claims 11-15, characterized in that the coating material has a melting point of at least 5°C below the melting point of the binder material. 17. Method according to any one of claims 11-16, characterized in that the detergent additive material is selected from the group consisting of enzymes, peroxyacid compounds, peroxygen and chlorine bleaches, fluorescent agents and peroxyacid bleach precursors. 18 . Method according to claim 17, characterized in that the detergent additive is a peroxyacid bleach precursor. 19. Method according to claim 18, characterized in that the peroxyacid bleach precursor is sodium 4-benzoyloxybenzenesulfonate. 20. Method according to claim 18 or 19, characterized in that the binder material has a solubility in water at 40°C of more than 20% by weight. 21. Washing powder mixture, characterized in that it comprises a detergent additive product according to any one of claims 1-10.